Konica Minolta A00F011, bizhub c20p, MAGICOLOR 4650EN, MAGICOLOR 4650DN Service Manual

SERVICE MANUAL

THEORY OF OPERATION

magicolor 4650ENmagicolor 4650EN
magicolor 4650DNmagicolor 4650DN

2007.11
Ver. 1.0

THEORY OF OPERATION TOTAL CONTENTS

SAFETY AND IMPORTANT WARNING ITEMS ..............................................................S-1

IMPORTANT NOTICE ................................................................................................S-1

DESCRIPTION ITEMS FOR DANGER, WARNING AND CAUTION .........................S-1

SAFETY WARNINGS .................................................................................................S-2

WARNING INDICATIONS ON THE MACHINE ........................................................S-18

MEASURES TO TAKE IN CASE OF AN ACCIDENT ....................................................S-21

Composition of the service manual ................................................................................. C-1

Notation of the service manual ....................................................................................... C-2

magicolor 4650EN/4650DN main body

Outline ............................................................................................................................ 1

Composition/Operation ................................................................................................... 9

Lower feeder unit

Outline ............................................................................................................................ 1

Composition/Operation ................................................................................................... 3

i

Blank Page

ii

SAFETY AND IMPORTANT WARNING ITEMS

SAFETY AND IMPORTANT WARNING ITEMS

Read carefully the safety and important warning Items described below to understand them
before doing service work.

IMPORTANT NOTICE

Because of possible hazards to an inexperienced person servicing this product as well as
the risk of damage to the product, KONICA MINOLTA BUSINESS TECHNOLOGIES, INC.
(hereafter called the KMBT) strongly recommends that all servicing be performed only by
KMBT-trained service technicians.
Changes may have been made to this product to improve its performance after this Service
Manual was printed. Accordingly, KMBT does not warrant, either explicitly or implicitly, that
the information contained in this service manual is complete and accurate.
The user of this service manual must assume all risks of personal injury and/or damage to
the product while servicing the product for which this service manual is intended.
Therefore, this service manual must be carefully read before doing service work both in the
course of technical training and even after that, for performing maintenance and control of
the product properly.
Keep this service manual also for future service.

DESCRIPTION ITEMS FOR DANGER, WARNING AND CAUTION

In this service manual, each of three expressions “ DANGER”, “ WARNING”, and
“ CAUTION” is defined as follows together with a symbol mark to be used in a limited
meaning.
When servicing the product, the relevant works (disassembling, reassembling, adjustment,
repair, maintenance, etc.) need to be conducted with utmost care.

DANGER: Action having a high possibility of suffering death or serious injury

WARNING: Action having a possibility of suffering death or serious injury

CAUTION: Action having a possibility of suffering a slight wound, medium

trouble, and property damage

Symbols used for safety and important warning items are defined as follows:

:Precaution when servicing the

product.

:Prohibition when servicing the

product.

:Direction when servicing the

product.

General

precaution

General

prohibition

General

instruction

Electric hazard High temperature

Do not touch

with wet hand

Unplug Ground/Earth

Do not

disassemble

S-1

SAFETY AND IMPORTANT WARNING ITEMS

SAFETY WARNINGS

[1] MODIFICATIONS NOT AUTHORIZED BY KONICA MINOLTA

BUSINESS TECHNOLOGIES, INC.

KONICA MINOLTA brand products are renowned for their high reliability. This reliability is
achieved through high-quality design and a solid service network.
Product design is a highly complicated and delicate process where numerous mechanical,
physical, and electrical aspects have to be taken into consideration, with the aim of arriving
at proper tolerances and safety factors. For this reason, unauthorized modifications involve
a high risk of degradation in performance and safety. Such modifications are therefore
strictly prohibited. the points listed below are not exhaustive, but they illustrate the reason­ing behind this policy.

Prohibited Actions

DANGER

• Using any cables or power cord not specified by KMBT.

• Using any fuse or thermostat not specified by KMBT.
Safety will not be assured, leading to a risk of fire and
injury.

• Disabling fuse functions or bridging fuse terminals with
wire, metal clips, solder or similar object.

• Disabling relay functions (such as wedging paper between
relay contacts)

• Disabling safety functions (interlocks, safety circuits, etc.)
Safety will not be assured, leading to a risk of fire and
injury.

• Making any modification to the product unless instructed
by KMBT

• Using parts not specified by KMBT

S-2

SAFETY AND IMPORTANT WARNING ITEMS

[2] POWER PLUG SELECTION

In some countries or areas, the power plug provided with the product may not fit wall outlet
used in the area. In that case, it is obligation of customer engineer (hereafter called the CE)
to attach appropriate power plug or power cord set in order to connect the product to the
supply.

Power Cord Set or Power Plug

WARNING

• Use power supply cord set which meets the following
criteria:

- provided with a plug having configuration intended for
the connection to wall outlet appropriate for the prod­uct's rated voltage and current, and

- the plug has pin/terminal(s) for grounding, and

- provided with three-conductor cable having enough cur­rent capacity, and

- the cord set meets regulatory requirements for the area.

Use of inadequate cord set leads to fire or electric shock.

• Attach power plug which meets the following criteria:

- having configuration intended for the connection to wall
outlet appropriate for the product's rated voltage and
current, and

- the plug has pin/terminal(s) for grounding, and

- meets regulatory requirements for the area.

Use of inadequate cord set leads to the product connect­ing to inadequate power supply (voltage, current capacity,
grounding), and may result in fire or electric shock.

• Conductors in the power cable must be connected to ter­minals of the plug according to the following order:

• Black or Brown: L (line)

• White or Light Blue: N (neutral)

• Green/Yellow: PE (earth)

Wrong connection may cancel safeguards within the
product, and results in fire or electric shock.

kw

S-3

SAFETY AND IMPORTANT WARNING ITEMS

[3] CHECKPOINTS WHEN PERFORMING ON-SITE SERVICE

KONICA MINOLTA brand products are extensively tested before shipping, to ensure that all
applicable safety standards are met, in order to protect the customer and customer engi­neer (hereafter called the CE) from the risk of injury. However, in daily use, any electrical
equipment may be subject to parts wear and eventual failure. In order to maintain safety
and reliability, the CE must perform regular safety checks.

1. Power Supply

Connection to Power Supply

WARNING

• Check that mains voltage is as specified.

Connection to wrong voltage supply may result in fire or
electric shock.

• Connect power plug directly into wall outlet having same
configuration as the plug.

Use of an adapter leads to the product connecting to
inadequate power supply (voltage, current capacity,
grounding), and may result in fire or electric shock.

If proper wall outlet is not available, advice the customer
to contact qualified electrician for the installation.

• Plug the power cord into the dedicated wall outlet with a
capacity greater than the maximum power consumption.

If excessive current flows in the wall outlet, fire may
result.

• If two or more power cords can be plugged into the wall
outlet, the total load must not exceed the rating of the wall
outlet.

If excessive current flows in the wall outlet, fire may
result.

• Make sure the power cord is plugged in the wall outlet
securely.

Contact problems may lead to increased resistance,
overheating, and the risk of fire.

kw

• Check whether the product is grounded properly.

If current leakage occurs in an ungrounded product, you
may suffer electric shock while operating the product.
Connect power plug to grounded wall outlet.

S-4

SAFETY AND IMPORTANT WARNING ITEMS

Power Plug and Cord

WARNING

• When using the power cord set (inlet type) that came with
this product, make sure the connector is securely inserted
in the inlet of the product.
When securing measure is provided, secure the cord with
the fixture properly.

If the power cord (inlet type) is not connected to the prod­uct securely, a contact problem may lead to increased
resistance, overheating, and risk of fire.

• Check whether the power cord is not stepped on or
pinched by a table and so on.

Overheating may occur there, leading to a risk of fire.

• Check whether the power cord is damaged. Check
whether the sheath is damaged.

If the power plug, cord, or sheath is damaged, replace
with a new power cord (with plug and connector on each
end) specified by KMBT. Using the damaged power cord
may result in fire or electric shock.

• Do not bundle or tie the power cord.

Overheating may occur there, leading to a risk of fire.

• Check whether dust is collected around the power plug
and wall outlet.

Using the power plug and wall outlet without removing
dust may result in fire.

• Do not insert the power plug into the wall outlet with a wet
hand.

The risk of electric shock exists.

• When unplugging the power cord, grasp the plug, not the
cable.

The cable may be broken, leading to a risk of fire and
electric shock.

S-5

SAFETY AND IMPORTANT WARNING ITEMS

Wiring

WARNING

• Never use multi-plug adapters to plug multiple power cords
in the same outlet.

If used, the risk of fire exists.

• When an extension cord is required, use a specified one.
Current that can flow in the extension cord is limited, so
using a too long extension cord may result in fire.

Do not use an extension cable reel with the cable taken
up. Fire may result.

2. Installation Requirements

Prohibited Installation Places

WARNING

• Do not place the product near flammable materials or vola­tile materials that may catch fire.

A risk of fire exists.

• Do not place the product in a place exposed to water such
as rain.

A risk of fire and electric shock exists.

When not Using the Product for a long time

WARNING

• When the product is not used over an extended period of
time (holidays, etc.), switch it off and unplug the power
cord.

Dust collected around the power plug and outlet may
cause fire.

S-6

SAFETY AND IMPORTANT WARNING ITEMS

Ventilation

CAUTION

• The product generates ozone gas during operation, but it
will not be harmful to the human body.

If a bad smell of ozone is present in the following cases,

ventilate the room.
a. When the product is used in a poorly ventilated room
b. When taking a lot of copies

c. When using multiple products at the same time

Stability

CAUTION

• Be sure to lock the caster stoppers.

In the case of an earthquake and so on, the product may

slide, leading to a injury.

Inspection before Servicing

CAUTION

• Before conducting an inspection, read all relevant docu­mentation (service manual, technical notices, etc.) and
proceed with the inspection following the prescribed pro­cedure in safety clothes, using only the prescribed tools.
Do not make any adjustment not described in the docu­mentation.

If the prescribed procedure or tool is not used, the prod­uct may break and a risk of injury or fire exists.

• Before conducting an inspection, be sure to disconnect
the power plugs from the product and options.

When the power plug is inserted in the wall outlet, some
units are still powered even if the POWER switch is
turned OFF. A risk of electric shock exists.

• The area around the fixing unit is hot.

You may get burnt.

S-7

SAFETY AND IMPORTANT WARNING ITEMS

Work Performed with the Product Powered On

WARNING

• Take every care when making adjustments or performing
an operation check with the product powered.

If you make adjustments or perform an operation check
with the external cover detached, you may touch live or
high-voltage parts or you may be caught in moving gears
or the timing belt, leading to a risk of injury.

• Take every care when servicing with the external cover
detached.

High-voltage exists around the drum unit. A risk of elec­tric shock exists.

Safety Checkpoints

WARNING

• Check the exterior and frame for edges, burrs, and other
damage.

The user or CE may be injured.

• Do not allow any metal parts such as clips, staples, and
screws to fall into the product.

They can short internal circuits and cause electric shock
or fire.

• Check wiring for squeezing and any other damage.

Current can leak, leading to a risk of electric shock or
fire.

• Carefully remove all toner remnants and dust from electri­cal parts and electrode units such as a charging corona
unit.

Current can leak, leading to a risk of product trouble or
fire.

• Check high-voltage cables and sheaths for any damage.

Current can leak, leading to a risk of electric shock or
fire.

S-8

SAFETY AND IMPORTANT WARNING ITEMS

Safety Checkpoints

WARNING

• Check electrode units such as a charging corona unit for
deterioration and sign of leakage.

Current can leak, leading to a risk of trouble or fire.

• Before disassembling or adjusting the write unit (P/H unit)
incorporating a laser, make sure that the power cord has
been disconnected.

The laser light can enter your eye, leading to a risk of
loss of eyesight.

• Do not remove the cover of the write unit. Do not supply
power with the write unit shifted from the specified mount­ing position.

The laser light can enter your eye, leading to a risk of
loss of eyesight.

• When replacing a lithium battery, replace it with a new lith­ium battery specified in the Parts Guide Manual. Dispose
of the used lithium battery using the method specified by
local authority.

Improper replacement can cause explosion.

• After replacing a part to which AC voltage is applied (e.g.,
optical lamp and fixing lamp), be sure to check the installa­tion state.

A risk of fire exists.

• Check the interlock switch and actuator for loosening and
check whether the interlock functions properly.

If the interlock does not function, you may receive an
electric shock or be injured when you insert your hand in
the product (e.g., for clearing paper jam).

• Make sure the wiring cannot come into contact with sharp
edges, burrs, or other pointed parts.

Current can leak, leading to a risk of electric shock or
fire.

S-9

SAFETY AND IMPORTANT WARNING ITEMS

Safety Checkpoints

WARNING

• Make sure that all screws, components, wiring, connec­tors, etc. that were removed for safety check and mainte­nance have been reinstalled in the original location. (Pay
special attention to forgotten connectors, pinched cables,
forgotten screws, etc.)

A risk of product trouble, electric shock, and fire exists.

Handling of Consumables

WARNING

• Toner and developer are not harmful substances, but care
must be taken not to breathe excessive amounts or let the
substances come into contact with eyes, etc. It may be
stimulative.

If the substances get in the eye, rinse with plenty of water
immediately. When symptoms are noticeable, consult a
physician.

• Never throw the used cartridge and toner into fire.

You may be burned due to dust explosion.

Handling of Service Materials

CAUTION

• Unplug the power cord from the wall outlet.

Drum cleaner (isopropyl alcohol) and roller cleaner (ace­tone-based) are highly flammable and must be handled
with care. A risk of fire exists.

• Do not replace the cover or turn the product ON before
any solvent remnants on the cleaned parts have fully
evaporated.

A risk of fire exists.

S-10

SAFETY AND IMPORTANT WARNING ITEMS

Handling of Service Materials

CAUTION

• Use only a small amount of cleaner at a time and take
care not to spill any liquid. If this happens, immediately
wipe it off.

A risk of fire exists.

• When using any solvent, ventilate the room well.

Breathing large quantities of organic solvents can lead to

discomfort.

S-11

SAFETY AND IMPORTANT WARNING ITEMS

[4] Used Batteries Precautions

ALL Areas

CAUTION
Danger of explosion if battery is incorrectly replaced.
Replace only with the same or equivalent type recommended by the manufacturer.
Dispose of used batteries according to the manufacturer’s instructions.

Germany

VORSICHT!
Explosionsgefahr bei unsachgemäßem Austausch der Batterie.
Ersatz nur durch denselben oder einen vom Hersteller empfohlenen gleichwertigen Typ.
Entsorgung gebrauchter Batterien nach Angaben des Herstellers.

France

AT TE N T IO N
Il y a danger d’explosion s’il y a remplacement incorrect de la batterie.
Remplacer uniquement avec une batterie du même type ou d’un type équivalent recom­mandé par le constructeur.
Mettre au rebut les batteries usagées conformément aux instructions du fabricant.

Denmark

Lithiumbatteri - Eksplosionsfare ved fejlagtig håndtering.
Udskiftning må kun ske med batteri af samme fabrikat og type.
Levér det brugte batteri tilbage til leverandøren.

Finland, Sweden

Paristo voi räjähtää, jos se on virheellisesti asennettu.
Vaihda paristo ainoastaan laitevalmistajan suosittelemaan tyyppiin.
Hävitä käytetty paristo valmistajan ohjeiden mukaisesti.

ADVARSEL!

VAR OlT US

VARNING
Explosionsfara vid felaktigt batteribyte.
Använd samma batterityp eller en ekvivalent typ som rekommenderas av apparat­tillverkaren.
Kassera använt batteri enligt fabrikantens instruktion.

Norway

Eksplosjonsfare ved feilaktig skifte av batteri.
Benytt samme batteritype eller en tilsvarende type anbefalt av apparatfabrikanten.
Brukte batterier kasseres i henhold til fabrikantens instruksjoner.

ADVARSEL

S-12

SAFETY AND IMPORTANT WARNING ITEMS

[5] Laser Safety

• This is a digital machine certified as a Class 1 laser product. There is no possibility of
danger from a laser, provided the machine is serviced according to the instruction in this
manual.

5.1 Internal Laser Radiation

semiconductor laser

Maximum power of the laser diode 15 mW

Maximum average radiation power (*) 8.5 µW

Wavelength 770-800 nm

*at laser aperture of the Print Head Unit

• This product employs a Class 3B laser diode that emits an invisible laser beam. The
laser diode and the scanning polygon mirror are incorporated in the print head unit.

• The print head unit is NOT A FIELD SERVICEABLE ITEM. Therefore, the print head unit
should not be opened under any circumstances.

Laser Aperture of
the Print Head Unit

A00FP0C505DA

S-13

SAFETY AND IMPORTANT WARNING ITEMS

U.S.A., Canada
(CDRH Regulation)

• This machine is certified as a Class 1 Laser product under Radiation Performance Stan­dard according to the Food, Drug and Cosmetic Act of 1990. Compliance is mandatory
for Laser products marketed in the United States and is reported to the Center for
Devices and Radiological Health (CDRH) of the U.S. Food and Drug Administration of
the U.S. Department of Health and Human Services (DHHS). This means that the device
does not produce hazardous laser radiation.

• The label shown on page S-16 indicates compliance with the CDRH regulations and
must be attached to laser products marketed in the United States.

.

CAUTION

• Use of controls, adjustments or performance of procedures other than those
specified in this manual may result in hazardous radiation exposure.

semiconductor laser

Maximum power of the laser diode 15 mW

Wavelength 770-800 nm

All Areas

CAUTION

• Use of controls, adjustments or performance of procedures other than those
specified in this manual may result in hazardous radiation exposure.

semiconductor laser

Maximum power of the laser diode 15 mW

Wavelength 770-800 nm

Denmark

ADVARSEL

• Usynlig laserstråling ved åbning, når sikkerhedsafbrydere er ude af funktion.
Undgå udsættelse for stråling. Klasse 1 laser produkt der opfylder IEC60825-1
sikkerheds kravene.

halvlederlaser

Laserdiodens højeste styrke 15 mW

bølgelængden 770-800 nm

S-14

SAFETY AND IMPORTANT WARNING ITEMS

Finland, Sweden

LUOKAN 1 LASERLAITE
KLASS 1 LASER APPARAT

VAR OITU S!

• Laitteen käyttäminen muulla kuin tässä käyttöohjeessa mainitulla tavalla saat­taa altistaa käyttäjän turvallisuusluokan 1 ylittävälle näkymättömälle laser­säteilylle.

puolijohdelaser

Laserdiodin suurin teho 15 mW

aallonpituus 770-800 nm

VARNING!

• Om apparaten används på annat sätt än i denna bruksanvisning specificerats,
kan användaren utsättas för osynlig laserstrålning, som överskrider gränsen för
laserklass 1.

halvledarlaser

Den maximala effekten för laserdioden 15 mW

våglängden 770-800 nm

VAR O!

• Avattaessa ja suojalukitus ohitettaessa olet alttiina näkymättomälle laser­säteilylle. Älä katso säteeseen.

VARNING!

• Osynlig laserstråining när denna del är öppnad och spärren är urkopplad.
Betrakta ej stråien.

Norway

ADVERSEL

• Dersom apparatet brukes på annen måte enn spesifisert i denne bruksanvisn­ing, kan brukeren utsettes för unsynlig laserstrålning, som overskrider grensen
for laser klass 1.

halvleder laser

Maksimal effekt till laserdiode 15 mW

bølgelengde 770-800 nm

S-15

SAFETY AND IMPORTANT WARNING ITEMS

5.2 Laser Safety Label

• A laser safety label is attached to the inside of the machine as shown below.

5.3 Laser Caution Label

• A laser caution label is attached to the outside of the machine as shown below.

A00FP0E500DA

S-16

A00FP0E501DA

SAFETY AND IMPORTANT WARNING ITEMS

5.4 PRECAUTIONS FOR HANDLING THE LASER EQUIPMENT

• When laser protective goggles are to be used, select ones with a lens conforming to the
above specifications.

• When a disassembly job needs to be performed in the laser beam path, such as when
working around the printerhead and PC Drum, be sure first to turn the printer OFF.

• If the job requires that the printer be left ON, take off your watch and ring and wear laser
protective goggles.

• A highly reflective tool can be dangerous if it is brought into the laser beam path. Use
utmost care when handling tools on the user’s premises.

• The Print Head is not to be disassembled or adjusted in the field. Replace the Unit or
Assembly including the Control Board. Therefore, remove the Laser Diode, and do not
perform Control Board trimmer adjustment.

S-17

SAFETY AND IMPORTANT WARNING ITEMS

WARNING INDICATIONS ON THE MACHINE

Caution labels shown are attached in some areas on/in the machine.
When accessing these areas for maintenance, repair, or adjustment, special care should
be taken to avoid burns and electric shock.

High voltage

• This area generates high voltage.
Be careful not to touch here when the power is
turned ON to avoid getting an electric shock.

CAUTION

• The area around the
Fuser Unit is extremely
hot.
Touching any part other
than those indicated
may result in burns.

S-18

A00FP0C502DA

SAFETY AND IMPORTANT WARNING ITEMS

High voltage

• This area generates high
voltage.
Be careful not to touch here
when the power is turned
ON to avoid getting an elec­tric shock.

High voltage

• This area generates high
voltage.
Be careful not to touch here
when the power is turned
ON to avoid getting an elec­tric shock.

A00FP0C503DA

S-19

SAFETY AND IMPORTANT WARNING ITEMS

P

U

S

H

Y

WARNING

• Do not burn used Print Units.
Toner expelled from the fire is dangerous.

WARNING

• Do not burn used Waste Toner Bottle.
Toner expelled from the fire is dangerous.

Y

WARNING

• Do not burn used Toner Cartridge.
Toner expelled from the fire is dangerous.

A00FP0C504DA

CAUTION:

• You may be burned or injured if you touch any area that you are advised not to
touch by any caution label. Do not remove caution labels. If any caution label has
come off or soiled and therefore the caution cannot be read, contact our Service
Office.

S-20

MEASURES TO TAKE IN CASE OF AN ACCIDENT

MEASURES TO TAKE IN CASE OF AN
ACCIDENT

1. If an accident has occurred, the distributor who has been notified first must immediately
take emergency measures to provide relief to affected persons and to prevent further
damage.

2. If a report of a serious accident has been received from a customer, an on-site evalua­tion must be carried out quickly and KMBT must be notified.

3. To determine the cause of the accident, conditions and materials must be recorded
through direct on-site checks, in accordance with instructions issued by KMBT.

4. For reports and measures concerning serious accidents, follow the regulations speci­fied by every distributor.

S-21

MEASURES TO TAKE IN CASE OF AN ACCIDENT

Blank Page

S-22

Composition of the service manual

This service manual consists of Theory of Operation section and Field Service section to
explain the main machine and its corresponding options.

Theory of Operation section gives, as information for the CE to get a full understanding of
the product, a rough outline of the object and role of each function, the relationship
between the electrical system and the mechanical system, and the timing of operation of
each part.

Field Service section gives, as information required by the CE at the site (or at the cus­tomer’s premise), a rough outline of the service schedule and its details, maintenance
steps, the object and role of each adjustment, error codes and supplementary information.

The basic configuration of each section is as follows. However some options may not be
applied to the following configuration.

<Theory of Operation section>

OUTLINE: Explanation of system configuration,

product specifications, unit configuration, and paper path

COMPOSITION/OPERATION: Explanation of configuration of each unit,

operating system, and control system

<Field service section>

GENERAL: Explanation of system configuration, and product

specifications

MAINTENANCE: Explanation of service schedule, maintenance steps, ser-

vice tools, removal/reinstallation methods of major parts,
and firmware version up method etc.

ADJUSTMENT/SETTING: Explanation of utility mode, service mode, and mechanical

adjustment etc.

TROUBLESHOOTING: Explanation of lists of jam codes and error codes, and

their countermeasures etc.

APPENDIX: Parts layout drawings, connector layout drawings, timing

chart, overall layout drawing are attached.

C-1

Notation of the service manual

A. Product name

In this manual, each of the products is described as follows:

magicolor 4650EN/4650DN Main body

(1)
(2) Microsoft Windows 98: Windows 98

Microsoft Windows Me: Windows Me

Microsoft Windows NT 4.0: Windows NT 4.0 or Windows NT

Microsoft Windows 2000: Windows 2000

Microsoft Windows XP: Windows XP

Microsoft Windows Vista: Windows Vista

When the description is made in combination of the OS’s mentioned above:

Windows 98/Me

Windows NT 4.0/2000

Windows NT/2000/XP/Vista

Windows 98/Me/ NT/2000/XP/Vista

B. Brand name

The company names and product names mentioned in this manual are the brand name or
the registered trademark of each company.

C. Feeding direction

• When the long side of the paper is parallel with the feeding direction, it is called short
edge feeding. The feeding direction which is perpendicular to the short edge feeding is
called the long edge feeding.

• Short edge feeding will be identified with [S (abbreviation for Short edge feeding)] on the
paper size. No specific notation is added for the long edge feeding.
When the size has only the short edge feeding with no long edge feeding, [S] will not be
added to the paper size.

<Sample notation>

Paper size Feeding direction Notation

A4

A3 Short edge feeding A3

Long edge feeding A4

Short edge feeding A4S

C-2

SERVICE MANUAL

THEORY OF OPERATION

magicolor 4650EN
magicolor 4650DN

Main Body

2007.11
Ver. 1.0

Revision history

After publication of this service manual, the parts and mechanism may be subject to change for
improvement of their performance.
Therefore, the descriptions given in this service manual may not coincide with the actual machine.

When any change has been made to the descriptions in the service manual, a revised version will be
issued with a revision mark added as required.

Revision mark:

• To indicate clearly a section revised, show to the left of the revised section.
A number within represents the number of times the revision has been made.

1

1

• To indicate clearly a section revised, show in the lower outside section of the correspond­ing page.
A number within represents the number of times the revision has been made.

NOTE

Revision marks shown in a page are restricted only to the latest ones with the old ones deleted.

• When a page revised in Ver. 2.0 has been changed in Ver. 3.0:
The revision marks for Ver. 3.0 only are shown with those for Ver. 2.0 deleted.

• When a page revised in Ver. 2.0 has not been changed in Ver. 3.0:
The revision marks for Ver. 2.0 are left as they are.

1

1

2007/11 1.0 — Issue of the first edition

Date Service manual Ver. Revision mark Descriptions of revision

Theory of operation Ver. 1.0 Nov. 2007

CONTENTS

magicolor 4650EN/4650DN main body

Outline

1. System configuration............................................................................................... 1

2. Product specifications ............................................................................................. 2

3. Section configuration............................................................................................... 5

4. Media path .............................................................................................................. 6

5. Image creation process........................................................................................... 7

Composition/Operation

6. Overall composition................................................................................................. 9

6.1 Timing chart at main body power on .................................................................... 9

6.2 Control block diagram......................................................................................... 10

7. Write section ......................................................................................................... 11

7.1 Composition........................................................................................................ 11

7.2 Operation............................................................................................................ 12

7.2.1 Overview ..................................................................................................... 12

7.2.2 Laser exposure process.............................................................................. 12

7.2.3 Laser emission timing ................................................................................. 13

7.2.4 Laser emission area.................................................................................... 13

7.2.5 Laser light intensity control ......................................................................... 14

7.2.6 Registration correction control .................................................................... 14

8. Toner supply section ............................................................................................. 15

8.1 Composition........................................................................................................ 15

8.2 Drive ................................................................................................................... 16

8.3 Operation............................................................................................................ 17

8.3.1 Toner conveying mechanism....................................................................... 17

8.3.2 Toner collecting port shutter mechanism .................................................... 18

8.3.3 Toner replenishing mechanism ................................................................... 19

8.3.4 Toner level detection ................................................................................... 20

8.3.5 Toner near-empty condition detection ......................................................... 20

8.3.6 Toner empty condition detection ................................................................. 21

8.3.7 Toner empty condition detection control ..................................................... 21

8.3.8 Toner cartridge life control........................................................................... 21

9. Print unit section (overall composition).................................................................. 22

9.1 Composition........................................................................................................ 22

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magicolor 4650DN

OutlineComposition/Operation

i

9.2 Operation............................................................................................................ 23

10. Print unit section (photo conductor) ...................................................................... 24

magicolor 4650EN

magicolor 4650DN

10.1 Composition ....................................................................................................... 24

10.2 Drive ................................................................................................................... 24

10.3 Operation............................................................................................................ 25

OutlineComposition/Operation

11. Print unit section (charge corona)......................................................................... 27

11.1 Composition ....................................................................................................... 27

11.2 Operation............................................................................................................ 28

12. Print unit section (developing)............................................................................... 29

12.1 Composition ....................................................................................................... 29

12.2 Operation............................................................................................................ 30

13. Transfer section (1st transfer)................................................................................ 35

13.1 Composition ....................................................................................................... 35

13.2 Drive ................................................................................................................... 36

13.3 Operation............................................................................................................ 37

Theory of operation Ver. 1.0 Nov. 2007

9.2.1 Print unit life detection ................................................................................ 23

9.2.2 Print unit life control .................................................................................... 23

10.3.1 Photo conductor drive mechanism ............................................................. 25

10.3.2 Photo conductor post-exposure control ...................................................... 26

10.3.3 Photo conductor total exposure control upon recovery............................... 26

10.3.4 Photo conductor small amount rotation control .......................................... 26

11.2.1 Charge corona unit ON/OFF control........................................................... 28

11.2.2 Ozone ventilation mechanism..................................................................... 28

12.2.1 Developing drive control ............................................................................. 30

12.2.2 Toner collecting port shutter mechanism .................................................... 31

12.2.3 Toner flow ................................................................................................... 32

12.2.4 Developing system...................................................................................... 33

12.2.5 Cleaning mechanism .................................................................................. 34

12.2.6 Toner collecting port shutter mechanism .................................................... 34

13.3.1 1st transfer output control ........................................................................... 37

13.3.2 1st transfer roller pressure/retraction control .............................................. 37

13.3.3 1st transfer roller pressure operation.......................................................... 38

13.3.4 1st transfer roller retraction operation......................................................... 39

13.3.5 1st transfer roller pressure/retraction position control................................. 40

13.3.6 Transfer belt cleaning mechanism .............................................................. 41

13.3.7 1st transfer belt cleaning control................................................................. 42

13.3.8 1st transfer belt backward rotation control.................................................. 42

13.3.9 Toner collecting port shutter mechanism .................................................... 43

ii

Theory of operation Ver. 1.0 Nov. 2007

14. Transfer section (2nd transfer)............................................................................... 44

14.1 Composition........................................................................................................ 44

14.2 Drive ................................................................................................................... 45

14.3 Operation ............................................................................................................ 45

14.3.1 2nd transfer roller pressure mechanism...................................................... 45

14.3.2 2nd transfer voltage control......................................................................... 47

14.3.3 2nd transfer voltage setting control (ATVC: auto transfer voltage control) ..47

14.3.4 2nd transfer roller cleaning control.............................................................. 48

15. Waste toner collecting section............................................................................... 49

15.1 Composition........................................................................................................ 49

15.2 Drive ................................................................................................................... 50

15.3 Operation ............................................................................................................ 51

15.3.1 Toner flow at the 1st transfer section .......................................................... 51

15.3.2 Toner flow at the 2nd transfer section ......................................................... 52

15.3.3 Toner collecting port shutter mechanism at the suction transport unit........ 53

15.3.4 Toner collecting port shutter mechanism of the waste toner bottle ............. 53

15.3.5 Waste toner box locking mechanism........................................................... 54

15.3.6 Waste toner box locked position detection mechanism .............................. 54

15.3.7 Waste toner box-in-position detection mechanism...................................... 55

15.3.8 Waste toner flow in the waste toner box ..................................................... 55

15.3.9 Waste toner near-full condition detection control ........................................ 56

15.3.10 Waste toner full condition detection control ................................................ 56

16. Media feed section (Tray 1) ................................................................................... 57

16.1 Composition........................................................................................................ 57

16.2 Drive ................................................................................................................... 58

16.3 Operation ............................................................................................................ 58

16.3.1 Media lift plate mechanism ......................................................................... 58

16.3.2 Media separation mechanism ..................................................................... 59

16.3.3 Media feed control....................................................................................... 59

16.3.4 Media empty condition detection control..................................................... 60

17. Media feed section (Tray 2) ................................................................................... 61

17.1 Composition........................................................................................................ 61

17.2 Drive ................................................................................................................... 62

17.3 Operation ............................................................................................................ 62

17.3.1 Media lift plate mechanism ......................................................................... 62

17.3.2 Media separation mechanism ..................................................................... 63

17.3.3 Media feed control....................................................................................... 63

17.3.4 Media supply level detection control ........................................................... 64

17.3.5 Media empty condition detection control..................................................... 64

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OutlineComposition/Operation

iii

18. Conveyance section (IDC sensor)......................................................................... 66

18.1 Composition ....................................................................................................... 66

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magicolor 4650DN

18.2 Operation............................................................................................................ 67

OutlineComposition/Operation

19. Conveyance section (Registration roller) .............................................................. 69

19.1 Composition ....................................................................................................... 69

19.2 Drive ................................................................................................................... 70

19.3 Operation............................................................................................................ 71

20. Fusing section....................................................................................................... 75

20.1 Composition ....................................................................................................... 75

20.2 Drive ................................................................................................................... 76

20.3 Operation............................................................................................................ 76

21. Image stabilization control .................................................................................... 83

21.1 Overview of image stabilization control .............................................................. 83

22. Miscellaneous ....................................................................................................... 86

Theory of operation Ver. 1.0 Nov. 2007

17.3.6 Tray open/close detection control ............................................................... 65

17.3.7 Media misfeed detection control ................................................................. 65

18.1.1 Drive ........................................................................................................... 67

18.2.1 Toner density detection control ................................................................... 67

18.2.2 IDC sensor calibration control..................................................................... 68

18.2.3 IDC sensor shutter mechanism .................................................................. 68

19.3.1 Conveyance speed control ......................................................................... 71

19.3.2 Registration roller control............................................................................ 71

19.3.3 Control of loop formed before registration roller ......................................... 72

19.3.4 Media neutralization.................................................................................... 72

19.3.5 OHP transparencies detection control ........................................................ 73

19.3.6 Media size error detection control............................................................... 74

19.3.7 Temperature/humidity sensor ..................................................................... 74

20.3.1 Fusing roller drive control ........................................................................... 76

20.3.2 Fusing temperature control......................................................................... 80

20.3.3 Warm-up control ......................................................................................... 80

20.3.4 Wait control................................................................................................. 81

20.3.5 Print control................................................................................................. 81

20.3.6 PPM control ................................................................................................ 82

20.3.7 Protection against abnormally high temperature ........................................ 82

21.1.1 Complete correction control........................................................................ 83

21.1.2 Simplified correction control........................................................................ 84

21.1.3 Individual registration control ...................................................................... 84

21.1.4 Image stabilization control execution request............................................. 85

iv

Theory of operation Ver. 1.0 Nov. 2007

22.1 Fan control.......................................................................................................... 86

22.1.1 Composition ................................................................................................ 86

22.1.2 Function ...................................................................................................... 86

22.1.3 Control ........................................................................................................ 87

23. Switchback/Duplex section.................................................................................... 89

23.1 Composition........................................................................................................ 89

23.2 Drive ................................................................................................................... 90

23.3 Operation ............................................................................................................ 91

23.3.1 Outline......................................................................................................... 91

23.3.2 Switchback guide movable mechanism ...................................................... 92

23.3.3 Paper exit switching mechanism ................................................................. 93

23.3.4 Transport /Paper re-feed mechanism.......................................................... 95

magicolor 4650EN

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OutlineComposition/Operation

v

magicolor 4650EN

magicolor 4650DN

OutlineComposition/Operation

Theory of operation Ver. 1.0 Nov. 2007

Blank Page

vi

Theory of operation Ver. 1.0 Nov. 2007 1. System configuration

Outline

1. System configuration

[4][5]

[1]

[3]

[2]

A011T1C501AA

[1] magicolor 4650EN/4650DN [4] Hard disk kit

[2] Lower feeder unit [5] CF adapter

[3] Memory (DIMM)

magicolor 4650EN

magicolor 4650DN

Outline

1

2. Product specifications Theory of operation Ver. 1.0 Nov. 2007

2. Product specifications

A. Type

Type Desktop tandem full-color A4 laser beam printer

Printing system Electro photographic Printing System

magicolor 4650EN

magicolor 4650DN

Exposure system 4 laser diode and 1 polygon mirror

PC drum type OPC (organic photo conductor)

Photoconductor
cleaning

Print resolution 600 dpi x 600 dpi x 4 bit

Media feeding system Two-way system (Tray 1: 100 sheets, Tray 2: 250 sheets)

Outline

Developing system Mono-component SMT

Charging system Needle charging system (with Ozone suction feature)

Transfer system Transfer belt system

Media separating
system

Fusing system Belt fusing

Media exit system Face down (Output tray capacity: A4S/Letter, 200 sheets)

B. Functions

Warm-up time

Process speed 144 mm/sec (plain paper, Monochrome/full color mode)

First-page-out-time 14.0 second (Full-color mode, A4S/Letter, 1-sided mode, plain paper)

Print speed 24 pages/min. (A4S, 1-sided print, plain paper)

Tray capacities Plain paper

Blade cleaning system

* Expandable up to a three-way system by adding lower feeder units (up to

one)

Curvature separation + charge-neutralizing system

Average: 36 sec. or less
(Power on to ready, at ambient temperature of 23° C/73.4° F and rated source
voltage)

25 pages/min. (Letter, 1-sided print, plain paper)

:100 sheets (Tray1)

Label, postcard, thick 1, thick 2, glossy 1, glossy 2,
transparency, letterhead
Envelop

250 sheets (Tray2)
:20 sheets (Tray1)

:10 sheets (Tray1)

2

Theory of operation Ver. 1.0 Nov. 2007 2. Product specifications

C. Media

Paper source (maximum tray capacity)

Tr ay 1 Tr ay 2

(100 sheets) (250 sheets)

(20 sheets)

92 to 216 mm
(3.6 to 8.5")

148 to 356 mm
(5.8 to 14.0")

-

92 to 216 mm (3.6 to 8.5")

148 to 297 mm
(5.8 to 11.7")

Media type

Media
dimensions

Ty pe

Plain paper
(60 to 90 g/m2; 16 to 24 lb bond)

Thick 1 (91 to 150 g/m2)

Thick 2 (151 to 210 g/m2)

Label

Letterhead

Transparencies

Glossy 1 (100-128 g/m2)

Glossy 2 (129-158 g/m2)

Postcard

Envelope (10 sheets)

Width

Length

D. Maintenance

Machine durability 400,000 prints or 5 years, whichever comes first

E. Machine specifications

Power requirements

Max power consumption

Dimensions 469 mm (W) x 536 mm (D) x 385 mm (H)

Weight 31.0 kg (68.3 lb) or less without consumables

Operating noise During standby : 39 dB (A) or less

Voltage: AC 100V, 120 V, 220 to 240 V

Frequency: 50 to 60 Hz ± 3 Hz

1200 W or less
16 W less (Energy saver mode)

18.5 inch (W) x 21.1 inch (D) x 15.2 inch (H)

During printing : 52 dB (A) or less

magicolor 4650EN

magicolor 4650DN

Outline

F. Operating Environment

Temperature 10° to 35° C / 50° F to 95° F

Humidity 15% to 85%

3

2. Product specifications Theory of operation Ver. 1.0 Nov. 2007

G. Print functions

Type Built-in type controller

Pentium 2: 400 MHz (Pentium 3: 500 MHz or higher is recom­mended)

Power Mac G3 or later (G4 or later is recommended)

Macintosh equipped with an Intel processor

Microsoft Windows Vista Home Basic/Home Premium/Ulti­mate/Business/Enterprise, Windows Vista Home Basic /Home
Premium /Ultimate/Business /Enterprise x64 Edition, Windows
XP Home Edition/Professional (Service Pack 1 or later; Service
Pack 2 or later is recommended), Windows XP Professional
x64 Edition, Windows Server 2003, Windows Server 2003 x64
Edition, Windows 2000 (Service Pack 4 or later)

Mac OS X (10.2 or later; We recommend installing the newest
patch), Mac OS X Server (10.2 or later)

Red Hat Linux 9.0, SuSE Linux 8.2

Approximately 20 MB of free hard disk space for printer driver
and Status Monitor

Approximately 128 MB of free hard disk space for image pro­cessing

10Base-T/100Base-TX/1000Base-T Ethernet interface port

USB Revision 2.0 compliant port

Parallel (IEEE 1284) port

magicolor 4650EN

magicolor 4650DN

Outline

System
Requirements

Personal computer

Operating System

Free hard disk space

RAM 128 MB or more

Interfaces

NOTE

• These specifications are subject to change without notice.

4

Theory of operation Ver. 1.0 Nov. 2007 3. Section configuration

3. Section configuration

Fusing section

Toner supply section

Transfer belt section

Transfer section

magicolor 4650EN

magicolor 4650DN

Print unit section

Media feed section
(Tray 2)

Duplex section

Media feed section
(Tray 1)

Write section

Outline

A011T1C502AA

5

4. Media path Theory of operation Ver. 1.0 Nov. 2007

4. Media path

magicolor 4650EN

magicolor 4650DN

Outline

A011T1C503AA

6

Theory of operation Ver. 1.0 Nov. 2007 5. Image creation process

5. Image creation process

[8] Media separation

[7] 2nd image transfer

[9] Transfer belt cleaning

[6] 1st image transfer

magicolor 4650EN

magicolor 4650DN

[2] PC drum

[5] Developing

[1] Printer processing [4] LD exposure

[1] Printer processing • The intensity of the laser light is controlled based on the image

signal transmitted from the host computer.

[2] PC drum • The image of the original projected onto the surface of the PC

drum is changed to a corresponding electrostatic latent image.

[3] PC drum charging • Apply DC (-) charge to the photo conductor.

[4] LD exposure • The surface of the PC drum is irradiated with laser light, and an

electrostatic latent image is thereby formed.

[5] Developing • The toner, agitated and negatively charged in the toner chamber,

is attracted onto the electrostatic latent image formed on the sur­face of the PC drum. It is thereby changed to a visible, developed
image.

[6] 1st image transfer • A DC positive voltage is applied to the backside of the transfer

belt, thereby allowing the visible, developed image on the surface
of each of the PC drums (Y, M, C and K) to be transferred onto
the transfer belt.

[7] 2nd image transfer • A DC positive voltage is applied to the backside of the media,

thereby allowing the visible, developed image on the surface of
the transfer belt to be transferred onto the media.

[8] Media separation • The media, which has undergone the 2nd image transfer process,

is neutralized so that it can be properly separated from the trans­fer belt.

[9] Transfer belt cleaning • The residual toner left on the surface of the transfer belt is

scraped off.

[10] PC drum cleaning • The residual toner left on the surface of the PC drum is scraped

off.

[10] PC drum cleaning

[3] PC drum charging

Outline

7

5. Image creation process Theory of operation Ver. 1.0 Nov. 2007

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Outline

Blank Page

8

Theory of operation Ver. 1.0 Nov. 2007 6. Overall composition

Composition/Operation

6. Overall composition

6.1 Timing chart at main body power on

Conditions: A4S plain paper

Polygon motor
LD

Transport motor(M3)

Color PC drum motor(M2)

Color developing motor(M1)

K developing motor(M5)

Charge K

magicolor 4650EN

magicolor 4650DN

Charge YMC

Developing Y

Developing Y

Developing Y

Developing Y

TOD Y

TOD M

TOD C

TOD K

1st transfer
pressure/retraction

1st transfer rem

2nd transfer
pressure/retraction

2nd transfer rem

Composition/Operation

A011T2E548AA

9

6. Overall composition Theory of operation Ver.1.0 Nov. 2007

6.2 Control block diagram

Operation board

magicolor 4650EN

magicolor 4650DN

Print control board (PRCB)

Image

processing

Leser drive board

TC/Y TC/M TC/C TC/K PU/Y PU/M PU/C PU/K

Composition/Operation

Control system line

Image bus line

MFP board (MFPB)

Media feed and
conveyance

CPU

Process

Fusing

Lower feeder unit

A011T2E549AA

10

Theory of operation Ver. 1.0 Nov. 2007 7. Write section

7. Write section

7.1 Composition

4138to2001c0

A011T2C515AA

Return mirror/2nd

G2 lens

magicolor 4650EN

magicolor 4650DN

Index board

G1 lens

Polygon mirror

SOS lens

Separation mirror

Return mirror/1st

Synthetic mirror

4138to2002c0

Semiconductor laser

Composition/Operation

11

7. Write section Theory of operation Ver.1.0 Nov. 2007

7.2 Operation

7.2.1 Overview

• Four semiconductor lasers provided, one for each of the four different colors. A single
polygon motor is used to make a scan motion.

magicolor 4650EN

• Each photo conductor is irradiated with a laser light so that an electrostatic latent image

magicolor 4650DN

is formed on it.

7.2.2 Laser exposure process

1. The laser light emitted by each of the semiconductor laser/Y, M, C, and K is
reflected onto the polygon mirror via the synthetic mirror.

2. Since the angle of incidence for each color of laser light varies, the laser light
reflected by the polygon mirror is reflected at a different angle for each color.

3. The condensing angle of each color of laser light is corrected by the G1 lens before
reaching each return mirror.

4. The K laser light is condensed on the surface of the photo conductor through the
separation mirror and G2 lens.

5. The Y, M, or C laser light is condensed on the photo conductor through the separa­tion mirror, G2 lens, and return mirror.

Index sensor

G1 lens

Composition/Operation

Polygon mirror

SOS lens

Separation mirror

Semiconductor
laser

Photo conductor

Return mirror/2nd

G2 lens

12

Y

M

C

K

Synthetic mirror

Y

Return mirror/1st

Y

M

MY

Y

C

CM

C

M

C

K

K

K

K

4138to2502c0

Theory of operation Ver. 1.0 Nov. 2007 7. Write section

7.2.3 Laser emission timing

• When a ready signal is detected after the lapse of a given period of time after the print
cycle has been started, a laser ON signal is output from the MFP board.

• The laser ON signal triggers the firing of each laser light, which illuminates the index
board via the polygon mirror, G1 lens, separation mirror (K), and SOS lens. This gener­ates an SOS signal.

• This SOS (Start of Scan) signal unifies the timing at which the laser lights are irradiated
for each main scan line.

• The SOS signal is generated only from the K laser light. For the other colors, the emis­sion timing is determined with reference to K.

7.2.4 Laser emission area

A. Main scan direction (FD)

• The print start position in the FD direction is determined by the FD print start signal
(HSYNC) that is output from the MFP board and the width of the media.

• The laser emission area is determined by the media size. However, there is a 4 mm/

0.157 inch wide void area on both the both edges of the media.

B. Sub scan direction (CD)

• The print start position in the CD direction is determined by the CD print start signal
(TOD) that is output from the MFP board and the length of the media. However, there is a
4 mm/0.157 inch wide void area on both edges of the media.

• The laser emission area is determined by the media size. However, there is a 4 mm/

0.157 inch wide void area on both the leading and trailing edges of the media.

magicolor 4650EN

magicolor 4650DN

Composition/Operation

Void width: 4 mm/0.157 inch

Void width: 4 mm/0.157 inch

Void width: 4 mm/0.157 inch

Void width: 4 mm/0.157 inch

4138to2595c0

13

7. Write section Theory of operation Ver.1.0 Nov. 2007

7.2.5 Laser light intensity control

• The laser light intensity control corrects the target level of fluctuations in fine line repro­duction and reverse image (white on black) reproduction that occur due to variations in
photo conductor electrostatic characteristics, developing characteristics, and transfer
characteristics (part-to-part variations, environment, durability).

magicolor 4650EN

• It is controlled integrally with other control items by the image stabilization control.

magicolor 4650DN

• The laser light intensity control is performed when there is a request made for execution
of an image stabilization sequence.

7.2.6 Registration correction control

• In a tandem engine that has an image forming process for each color of toner, incorrect
color registration tends to occur due to variations in parts of the main body used for reg­ulating the drawing positions. The registration correction control automatically detects
and corrects this incorrect color registration.

• It is controlled integrally with other control items by the image stabilization control.

• The registration correction control is performed when there is a request made for execu­tion of image stabilization sequence.

Composition/Operation

14

Theory of operation Ver. 1.0 Nov. 2007 8. Toner supply section

8. Toner supply section

8.1 Composition

magicolor 4650EN

magicolor 4650DN

TC detection board (CSIC)

Conveyance screw

A011T2C516AA

A011T2C006DA

Toner collecting port

Agitating blade

Conveyance screw

A011T2C525AA

Composition/Operation

A011T2C007DA

15

8. Toner supply section Theory of operation Ver.1.0 Nov. 2007

8.2 Drive

Front view

magicolor 4650EN

magicolor 4650DN

3D view

Toner supply motor/Y, M (M6)

Composition/Operation

Toner supply motor/Y, M (M6)

4138to2599c0

Toner supply motor/C, K (M7)

Agitating blade

Toner supply motor/C, K (M7)

16

Conveyance screw

A011T2C008DA

Theory of operation Ver. 1.0 Nov. 2007 8. Toner supply section

8.3 Operation

8.3.1 Toner conveying mechanism

• The toner supply motor is turned either forward or backward to drive the agitating blade
and the conveyance screw.

• The agitating blade provided in the toner cartridge agitates and conveys toner to the con­veyance screw.

• The toner conveyed by the agitating blade is conveyed to the toner collecting port sitting
on the front side of the main body by the conveyance screw.

magicolor 4650EN

magicolor 4650DN

Conveyance screwAgitating blade

Conveyance screwAgitating blade

A011T2C007DA A011T2C009DA

A011T2C006DA

Rear side

Toner collecting port

Composition/Operation

17

8. Toner supply section Theory of operation Ver.1.0 Nov. 2007

8.3.2 Toner collecting port shutter mechanism

• The toner collecting port is equipped with a shutter mechanism that prevents toner from
being spilled out when the toner cartridge is removed from the main body.

• After installing the toner cartridge into the main body, placing the print unit release lever
in its locked position opens the shutter of the toner collecting port. Then toner can be

magicolor 4650EN

magicolor 4650DN

conveyed to the main body.

• Moving the print unit release lever to the right or left accompanies the synchronizing
movement of the slider. This makes the gear connected to the shutter rotated and then
makes the shutter opened or closed.

• To prevent the front door from getting closed while the shutter is open, the preventive
mechanism works in the way that the front door cannot be closed by interfering with the
release lever until the release lever is placed in the locked position (to the left in the pic­ture).

Slider

Composition/Operation

Release lever

A011T2C010DA A011T2C011DA

Close

Open

Shutter

18

Theory of operation Ver. 1.0 Nov. 2007 8. Toner supply section

8.3.3 Toner replenishing mechanism

• The toner supply motor is energized according to the condition of the toner level sensor
for each color of toner. Toner is then supplied from the toner cartridge to the print unit as
necessary.

• A single toner supply motor is turned either forward or backward to accomplish supply of
toner of two different colors (one motor is for Y and M, and the other for C and K). That is,
M (K) toner cannot be supplied while Y (C) toner is being supplied.

• Toner is supplied only while the print unit is being driven. This is because of the following
reason: if toner is supplied from the toner cartridge while the print unit remains station­ary, toner stagnates at the print unit.

magicolor 4650EN

magicolor 4650DN

Toner supply

motor

/Y, /M (M6)

/C, /K (M7)

Direction of rotation

(as viewed from above of motor

shaft)

Forward (clockwise) Turned Stationary Stationary Stationary

Backward (counterclockwise) Stationary Turned Stationary Stationary

Forward (clockwise) Stationary Stationary Turned Stationary

Backward (counterclockwise) Stationary Stationary Stationary Turned

Toner supply (Agitating blade/conveyance screw)

YMCK

When the motor turns forward When the motor turns backward

Toner supply motor (M6)

Y

Y/C one-way clutch turns. M/K one-way clutch turns.

C

4138to2013c0

Toner supply motor (M7)

M

Composition/Operation

K

4138to2014c0

19

8. Toner supply section Theory of operation Ver.1.0 Nov. 2007

8.3.4 Toner level detection

• The toner level is determined by the accumulated time of rotation of the toner supply
motor.

• The toner level can be checked through MENU/PRINT MENU/STATISTICS PAGE.

magicolor 4650EN

8.3.5 Toner near-empty condition detection

magicolor 4650DN

• The cumulative period of time through which the toner supply motor is energized is
detected as the basis for determining whether there is a toner near-empty condition.

• The main body is designed to indicate a toner near-empty condition when the toner level
remaining in the toner cartridge becomes approx. 40 percent.

Toner cartridge

Quantity equivalent to 3,000 printed

Quantity equivalent to 4,000 printed Approx. 1,600 sheets

Quantity equivalent to 8,000 printed Approx. 3,200 sheets

Toner level

(Targeted percent)

60%

Pages that can be printed after toner near-

empty detection (Targeted number of

* for a standard original of a 5% coverage rate

• A toner near-empty condition is reset when a new toner cartridge is detected.

Composition/Operation

pages) *

Approx. 1,200 sheets

20

Theory of operation Ver. 1.0 Nov. 2007 8. Toner supply section

8.3.6 Toner empty condition detection A. Toner empty condition detection mechanism

• The print unit has a toner empty condition detecting mechanism.
Based on the amount of toner conveyed from the toner cartridge to the print unit, a toner
empty condition is detected.

• A toner level in the print unit is detected by the LED and toner level sensor mounted on
the toner level sensor board provided in the main body.

• Light emitted from the LED travels through the light guiding path and is guided into the
print unit.

• The toner level sensor detects the intensity of the transmitted light guided through the
light guiding path from the inside of the toner cartridge. The toner level is thereby esti­mated.

• To ensure correct detection of the intensity of transmitted light by the toner level sensor, a
cleaning sheet is provided that cleans the window in the light guiding path periodically.

LED Sensor

Cleaning sheet

Light guiding path

Cleaning sheet

Print unit

4138to2012c1

Print unit

4138to2012c2

magicolor 4650EN

magicolor 4650DN

Composition/Operation

8.3.7 Toner empty condition detection control

• A sequence is started for detecting a toner empty condition when a toner near-empty
condition is detected. (In starter cartridges shipped with a main body, the toner empty
detection control always functions.)

• The main body determines that there is a toner empty condition when the toner level
sensor output value remains below a predetermined value and if the following event is
detected a predetermined number of consecutive times: the output value of the toner
level sensor remains a predetermined value or lower for more than a predetermined
period of time.

• The consecutive detection count is retained even when power is turned OFF.

• A toner empty condition is reset when a new toner cartridge is detected.

8.3.8 Toner cartridge life control

• Each toner cartridge is provided with a TC detection board that detects state of a toner
cartridge placement, a new TC, a toner near-empty condition, and a toner empty condi­tion.

21

9. Print unit section (overall composition) Theory of operation Ver.1.0 Nov. 2007

9. Print unit section (overall composition)

9.1 Composition

magicolor 4650EN

magicolor 4650DN

A011T2C517AA

PU detection board (CSIC)PC motor

Composition/Operation

Developing motor

Replenishing screw

Agitating screw

Supply roller

Developing roller

Photo conductor

Cleaning blade

Charge corona

A011T2C014DA

A011T2C526AA

A011T2C013DA

Toner collecting
screw

22

Theory of operation Ver. 1.0 Nov. 2007 9. Print unit section (overall composition)

9.2 Operation

9.2.1 Print unit life detection

• Based on the photo conductor driving time, the cartridge life is determined.

• When the photo conductor driving time reaches its near life, the near life warning mes­sage appears.

• When the photo conductor driving time reaches its life time, the life warning message
appears.

• If the photo conductor runs more than its life, a life end warning message appears. When
the warning message appears, you cannot print.

• The life end message can be reset when the print unit is replaced.

9.2.2 Print unit life control

• Each print unit is provided with a PU detection board that detects state of a toner car­tridge placement, a new PU, a print unit life.

• The main body attempts to perform a detection sequence when the front door is closed.

• When a cartridge is detected as a new one, an image stabilization sequence starts.

magicolor 4650EN

magicolor 4650DN

Composition/Operation

23

10. Print unit section (photo conductor) Theory of operation Ver.1.0 Nov. 2007

10. Print unit section (photo conductor)

10.1 Composition

Photo conductor

magicolor 4650EN

magicolor 4650DN

Composition/Operation

10.2 Drive

A011T2C517AA

Photo conductor

Charge
corona

4138to2018c4

A011T2C526AA

Charge transport layer Aluminum base

Charge
generating

Direction of
rotation

Transport motor (M3)

layer

4138to2505c1

24

Color PC drum
motor (M2)

Photo conductor

A011T2C015DA

Theory of operation Ver. 1.0 Nov. 2007 10. Print unit section (photo conductor)

10.3 Operation

10.3.1 Photo conductor drive mechanism

• Motors are used for the drive mechanism independently of the developing system to sup­press incorrect color registration and uneven pitch.

• To stop the drive for the color toner cartridges in the monochrome mode, different motors
are used to drive the color photo conductors and black photo conductor.

• The color PC drum motor drives the photo conductor/Y, M, and C, while the Transport
motor drives the photo conductor/K.

• In addition to the photo conductor/K, the Transport motor also drives the transfer system,
media feed system, and synchronizing drive system.

• Gears having a large diameter are used to enhance rotating accuracy of the photo con­ductors.

• The use of gears having a large diameter provides a large number of gear teeth, which
suppresses uneven pitch and eccentricity.

• Drive is transmitted to each of the photo conductors when the coupling on the drive end
is engaged with that on the driven end.

Transport motor (M3)

Color PC drum motor (M2)

magicolor 4650EN

magicolor 4650DN

Coupling

Large-diameter
gear

4138to2027c0

Composition/Operation

K

C

M

Y

25

10. Print unit section (photo conductor) Theory of operation Ver.1.0 Nov. 2007

10.3.2 Photo conductor post-exposure control

• The entire surface of the photo conductor is exposed to light before the photo conductor
stops rotating during the stop sequence or color change sequence (from the color print to
monochrome print) after a print cycle.

• Ozone stagnant in areas near the charge corona unit is adsorbed on the surface of the

magicolor 4650EN

magicolor 4650DN

photo conductor. This reduces sensitivity of the photo conductor, causing white bands to
occur in the image.

• To prevent this image failure from occurring, the entire surface of the photo conductor is
exposed to light and thus neutralized. This effectively prevents the surface of the photo
conductor from absorbing ozone.

10.3.3 Photo conductor total exposure control upon recovery

• If the “Photo conductor post-exposure control” described above is not correctly done, the
entire surface of the photo conductor is exposed to light, thereby preventing ozone from
being adsorbed on the surface of the photo conductor.

• If the “Photo conductor post-exposure control” is not performed due to a media misfeed
or malfunction, the entire surface of the photo conductor is exposed to light at the same
time that the “2nd transfer roller cleaning control” is performed during the recovery proce­dure from the media misfeed or malfunction.

10.3.4 Photo conductor small amount rotation control

• Ozone stagnant in areas near the charge corona unit reduces sensitivity of the photo

Composition/Operation

conductors, causing white bands to occur in the image.

• To prevent this image problem, the photo conductor is turned so as to allow its surface
facing the charge corona unit to deviate, thereby preventing the surface sensitivity from
being reduced.

26

Theory of operation Ver. 1.0 Nov. 2007 11. Print unit section (charge corona)

11. Print unit section (charge corona)

11.1 Composition

magicolor 4650EN

magicolor 4650DN

Charge corona

A011T2C517AA

A011T2C017DA

Grid mesh

Electrode

A011T2C526AA

Charge
corona

A011T2C018DA

Composition/Operation

27

11. Print unit section (charge corona) Theory of operation Ver.1.0 Nov. 2007

11.2 Operation

11.2.1 Charge corona unit ON/OFF control

Polygon motor

magicolor 4650EN

magicolor 4650DN

11.2.2 Ozone ventilation mechanism

• Ozone stagnant in areas near the charge corona unit reduces sensitivity of the photo

Composition/Operation

conductor, causing white bands to occur in the image.

• The ozone filter is used to remove ozone produced by the charge corona unit, thereby
preventing sensitivity of the photo conductor surface from being degraded.

• Outside air is drawn in through the opening provided at the front end of the charge
corona unit and is discharged together with ozone through the opening provided in the
rear.

• The ozone ventilation fan motor located in the rear of the main body draws air to allow
the discharged ozone to be removed by the ozone filter.

semiconductor laser

Transport motor (M3)

Color PC drum motor (M2)

Color developing motor (M1)

K developing motor (M5)

Charge K

Charge YMC

Ozone filter

K

C

M

A011T2C574AA

Y

Ozone ventilation fan motor (FM3)

28

A011T2C579AA

Theory of operation Ver. 1.0 Nov. 2007 12. Print unit section (developing)

12. Print unit section (developing)

12.1 Composition

magicolor 4650EN

magicolor 4650DN

Replenishing screw

Agitating screw

Supply roller

Color developing motor (M1)

A011T2C517AA

Developing roller

M

Y

A011T2C019DA

Toner collecting
screw

K developing motor (M5)

C

Photo conductor

Cleaning
blade

Charge
corona

A011T2C014DA

A011T2C526AA

Composition/Operation

K

A011T2C512AA

29

12. Print unit section (developing) Theory of operation Ver.1.0 Nov. 2007

12.2 Operation

12.2.1 Developing drive control

Polygon motor

magicolor 4650EN

magicolor 4650DN

Composition/Operation

Transport motor (M3)

Color PC drum motor (M2)

Color PC drum motor (M1)

K developing motor (M5)

Charge K

Charge YMC

Developing Y

Developing M

Developing C

Developing K

1st transfer pressure

30

1st transfer rem

2nd transfer pressure

2nd transfer rem

A011T2C575AA

Theory of operation Ver. 1.0 Nov. 2007 12. Print unit section (developing)

12.2.2 Toner collecting port shutter mechanism

• The toner collecting port is equipped with a shutter mechanism that prevents toner from
being spilled out when the print unit is removed from the main body.

• After installing the print unit and the toner cartridges into the main body, locking the print
unit release lever opens the collecting port shutter. Then toner can be replenished from
the toner cartridges.

• Moving the print unit release lever to the right or left accompanies the synchronizing
movement of the slider. This makes the shutter opened or closed.

• To prevent the front door from getting closed while the shutter is open, the preventive
mechanism works in the way that the front door cannot be closed by interfering with the
release lever until the release lever is placed in the locked position (to the left in the pic­ture).

Closed

Shutter

Opened

magicolor 4650EN

magicolor 4650DN

Release lever

Composition/Operation

A011T2C010DA A011T2C021DA

31

12. Print unit section (developing) Theory of operation Ver.1.0 Nov. 2007

12.2.3 Toner flow

1. Toner stored in the toner cartridge is agitated by the agitating blade and conveyed
onto the front side of the toner cartridge by the conveyance screw.

2. Toner conveyed onto the front side of the toner cartridge is conveyed through the
toner collecting port and then conveyed to the print unit collecting port.

magicolor 4650EN

magicolor 4650DN

3. The toner conveyed to the collecting port is conveyed into the toner chamber by the
replenishing screw.

4. The toner level detection system provided on the front side of the developing unit
(the sensor is mounted on the main body side) detects, at this time, the level of
toner still available for use in the toner chamber.

5. The toner conveyed to the toner chamber is agitated (charged) by the replenishing
screw and agitating screw.

6. Toner conveyed onto the rear side of the toner chamber is fed to the supply roller.

7. Toner fed to the supply roller is conveyed onto the developing roller.
At this time, the regulator blade/1st and /2nd regulate the height of toner on the sur­face of the developing roller.

8. Toner on the developing roller is fed to the electrostatic latent image formed on the
surface of the photo conductor.

9. Toner left on the developing roller is neutralized and returned to the supply roller.

10. The toner on the surface of the photo conductor is transferred onto the transfer belt.

11. Toner left on the surface of the photo conductor is scraped off by the cleaning
blade.

12. The toner scraped off by the cleaning blade is conveyed to the waste toner convey-

Composition/Operation

ance section by the toner collecting screw.

13. The toner conveyed by the toner collecting screw is conveyed and stored as waste
toner in the waste toner bottle.

Toner collecting port

Replenishing screw

Agitating screw

32

Replenishing
screw

Supply roller

Developing roller

Agitating screw

Toner collecting screw

K

C

M

Y

Transfer belt

Photo conductor

Cleaning blade

Toner collecting screw

A011T2E079DA

Theory of operation Ver. 1.0 Nov. 2007 12. Print unit section (developing)

12.2.4 Developing system

• Two types of developing systems are used, a non-contact developing system and an
alternating current application system.

1. A negative charge (supply bias voltage Vr) is applied the supply roller to regulate
the amount of toner sticking to the developing roller.

2. A negative charge (blade bias voltage Vb1) is applied to the regulator blade/1st to
negatively charge the toner and form a thin layer of toner.

3. Toner on the surface of the developing roller is evened out by the regulator blade/
2nd.

4. During development, DC + AC developing bias voltage (Vb) is applied to develop­ing roller. The AC component of the developing bias voltage is applied only during
development. At any time other than the development, only the DC component of
the developing bias voltage is applied.

5. Toner sticks to the photo conductor when the AC component of the developing bias
voltage (Vpp) is negative. The voltage and time length of the negative component
(Vpp) determines the image density.

6. A negative charge (charge neutralizing bias voltage: same potential as the develop­ing bias) is applied to the charge neutralizing sheet to neutralize any toner left on
the surface of the developing roller. The neutralized toner is returned to the supply
roller.

Charge neutralizing sheet

magicolor 4650EN

magicolor 4650DN

Supply roller

Developing roller

Regulator blade/1st

Regulator blade/2nd

Charge corona

Photo conductor

A011T2C024DB

Charge neutralizing sheet/ Developing roller bias

Supply roller bias

Regulator blade bias

Grid mesh

A011T2C025DA

Composition/Operation

33

12. Print unit section (developing) Theory of operation Ver.1.0 Nov. 2007

12.2.5 Cleaning mechanism A. Cleaning operation

1. The cleaning blade is pressed against the surface of the photo conductor to
remove toner left off the surface (fixed blade system).

magicolor 4650EN

magicolor 4650DN

2. The toner, which has been scraped off by the cleaning blade, is conveyed by the
toner collecting screw and collected in the waste toner transport section.

Cleaning blade

A011T2C027DA A011T2C028DA

12.2.6 Toner collecting port shutter mechanism

• The toner collecting port is equipped with a shutter mechanism that prevents toner from

Composition/Operation

being spilled out when the print unit is removed from the main body.

• When the print unit is installed into the main body, the shutter of the toner collecting port
opens and toner can be discharged from the print unit.

Toner collecting port

Closed

Opened

Photo conductor

Cleaning blade

Toner collecting
screw

34

A011T2C029DA A011T2C030DA

Toner collecting port

Theory of operation Ver. 1.0 Nov. 2007 13. Transfer section (1st transfer)

13. Transfer section (1st transfer)

13.1 Composition

magicolor 4650EN

magicolor 4650DN

A011T2C518AA

1st image transfer retraction position sensor (PS9)

Sliding plate

Retraction lever/Y, M, C

1st transfer roller/Y

Driven roller
Cleaning blade
Toner collecting screw

1st image transfer pressure/retraction clutch (CL4)

Transport motor (M3)

1st transfer roller/C

1st transfer roller/M

Transfer belt drive roller

Transfer belt

1st transfer roller/K

Pressure cam

4138to2035c2

A011T2C527AA

Composition/Operation

Toner collecting port

A011T2C032DA

35

13. Transfer section (1st transfer) Theory of operation Ver.1.0 Nov. 2007

13.2 Drive

1st image transfer pressure/retraction
clutch (CL4)

magicolor 4650EN

magicolor 4650DN

Transport motor (M3)

4138to2038c0

Mechanism for driving the belt

1st image transfer pressure/retraction
clutch (CL4)

Transport motor (M3)

Transfer belt

Composition/Operation

Driven roller

Mechanism for driving the pressure/retraction motion

Sliding plate

Toner collecting screw

Pressure cam

Transfer belt drive roller

4138to2041c1

1st transfer roller/Y, /M, /C, /K

Sliding plate

A011T2C033DA

36

Theory of operation Ver. 1.0 Nov. 2007 13. Transfer section (1st transfer)

13.3 Operation

13.3.1 1st transfer output control

• To transfer the toner image from the photo conductor to the transfer belt, the transfer volt­age is applied to the 1st transfer roller.

• A charge of the same potential is applied to each of the 1st transfer rollers.

• The transfer voltage is applied after the 1st transfer roller/Y, M, C is pressed against the
transfer belt for color mode.

• The transfer output is turned OFF after the last image moves past the 2nd transfer sec­tion.

13.3.2 1st transfer roller pressure/retraction control

• To extend the service life of the photo conductor/Y, M, C, the pressure position of the 1st
transfer roller is changed between the monochrome mode and the color mode.
The 1st transfer roller/K is not provided with a retraction mechanism; the transfer belt is
pressed against the photo conductor/K at all times.

• The Transport motor provides the drive for pressure/retraction operation of the 1st trans­fer roller/Y, M, C.

A. Monochrome mode

• The 1st transfer roller/Y, M, C is moved inward the unit (for retraction) and the photo con­ductor/Y, M, C is stopped. The transfer roller is moved (retracted) and the photo conduc­tor is stopped also in the ordinary standby state.

B. Color mode

• During the 1st transfer in the color mode, the 1st transfer roller/Y, M, C is moved toward
the photo conductor (pressed) so that transfer belt is pressed against the photo conduc­tor.

C. Others

• The transfer roller is moved (retracted) and the photo conductor is stopped in the ordi­nary standby state.

magicolor 4650EN

magicolor 4650DN

Composition/Operation

37

13. Transfer section (1st transfer) Theory of operation Ver.1.0 Nov. 2007

13.3.3 1st transfer roller pressure operation

1. Rotation of the Transport motor is transmitted by a gear train to the 1st image trans­fer pressure/retraction clutch.

2. Rotation of the 1st image transfer pressure/retraction clutch turns the pressure
cam, which moves the sliding plate.

magicolor 4650EN

magicolor 4650DN

3. As the sliding plate moves, the retraction lever turns.

4. As the retraction lever turns, the 1st transfer roller is pressed against the transfer
belt.

Sliding plate Pressure cam

Retraction lever

1st transfer roller

Composition/Operation

Photo conductor

4138to2044c1

38

Theory of operation Ver. 1.0 Nov. 2007 13. Transfer section (1st transfer)

13.3.4 1st transfer roller retraction operation

1. Rotation of the Transport motor is transmitted by a gear train to the 1st image trans­fer pressure/retraction clutch.

2. Rotation of the 1st image transfer pressure/retraction clutch turns the pressure
cam, which moves the sliding plate.

3. As the sliding plate moves, the retraction lever turns.

4. As the retraction lever turns, the 1st transfer roller is retracted from the transfer belt.

Sliding plate Pressure cam

Retraction lever

1st transfer roller

Photo conductor

4138to2045c1

magicolor 4650EN

magicolor 4650DN

Composition/Operation

39

13. Transfer section (1st transfer) Theory of operation Ver.1.0 Nov. 2007

13.3.5 1st transfer roller pressure/retraction position control A. Pressure position control

• The pressure and retraction operation of the 1st transfer roller is controlled as the 1st
image transfer retraction position sensor detects the movement of the sliding plate.

1. The 1st image transfer pressure/retraction clutch is energized.

magicolor 4650EN

magicolor 4650DN

2. The sliding plate is moved to press the 1st transfer rollers up against the transfer
belt, which blocks the 1st image transfer retraction position sensor.

3. After the lapse of a predetermined period of time after the 1st image transfer retrac­tion position sensor has been blocked, the 1st image transfer pressure/retraction
clutch is de-energized.

B. Retraction position control

• The pressure and retraction operation of the 1st transfer roller is controlled as the 1st
image transfer retraction position sensor detects the movement of the sliding plate.

1. The 1st image transfer pressure/retraction clutch is energized.

2. The sliding plate is moved to retract the 1st transfer rollers from the transfer belt. As
a result, the 1st image transfer retraction position sensor, which has been blocked,
is now unblocked.

3. After the lapse of a predetermined period of time after the 1st image transfer retrac­tion position sensor has been unblocked, the 1st image transfer pressure/retraction
clutch is de-energized.

1st image transfer retraction position sensor (PS9)

Sliding plate

Composition/Operation

40

4138to2046c1

Theory of operation Ver. 1.0 Nov. 2007 13. Transfer section (1st transfer)

13.3.6 Transfer belt cleaning mechanism

• To scrape residual toner off the surface of the transfer belt, the transfer belt is provided
with a cleaning blade.

• The cleaning blade is in pressed contact with the transfer belt at all times. That is, it
cleans the surface of the transfer belt as long as the belt turns.

• The toner scraped off by the cleaning blade is collected to the middle of the transfer belt
by the toner collecting screw.

• The collected waste toner is conveyed through the waste toner collecting port located at
the middle of the transfer belt unit and the suction transport unit, and brought to the
waste toner box.

Cleaning blade

Transfer belt

Toner collecting screw

4138to2035c1

magicolor 4650EN

magicolor 4650DN

Composition/Operation

Waste toner
collecting port

Toner collecting screw

A011T2C034DA

41

13. Transfer section (1st transfer) Theory of operation Ver.1.0 Nov. 2007

13.3.7 1st transfer belt cleaning control

• If there is a possibility of the main body being stopped with toner left on the surface of the
transfer belt between the cleaning blade position and the 2nd transfer position (due to a
media misfeed or malfunction), the Transport motor is energized to turn the transfer belt.
The residual toner is thereby removed from the transfer belt.

magicolor 4650EN

• No forced cleaning sequence is carried out to clean the entire surface of the transfer belt.

magicolor 4650DN

A. Operation timing

• The 1st transfer cleaning sequence is carried out before the 2nd transfer cleaning as part
of the initial operation sequence.

• The 1st transfer cleaning sequence is carried out before the 2nd transfer cleaning opera­tion is performed by the ATVC control system.

1st transfer belt cleaning area

13.3.8 1st transfer belt backward rotation control

Composition/Operation

• To prevent media dust, toner, and other foreign matter from being wedged in the cleaning
blade while the transfer belt remains stationary, the transfer belt is turned backward so
that the foreign matter can be removed.

• Once the transfer belt is started turning backward, this operation takes precedence over
any other request for energizing the Transport motor. Such a request is honored after the
backward rotation control is completed.

A. Operation timing

• The 1st transfer belt backward rotation is performed after a predetermined number of
printed pages are produced after the execution of the last backward rotation control.

4138to2049c1

42

Theory of operation Ver. 1.0 Nov. 2007 13. Transfer section (1st transfer)

13.3.9 Toner collecting port shutter mechanism

• A shutter mechanism is provided to prevent waste toner from being spilled from the toner
collecting port when the waste toner box is removed and reinstalled.

• Placing the shutter lever in the “locked” position (to the front side of the main body)
closes the shutter of the toner collecting port.

• The transfer belt unit can be removed after removing the waste toner box, closing the
shutter of the toner collecting port, and removing the fixing screws.

• A preventive mechanism works to stop the transfer belt unit from being removed with the
toner collecting port opened. Due to the shutter lever interfering with the suction trans­port unit, the transfer belt unit cannot be removed until the shutter lever is placed in the
locked position. Similarly, to install the transfer belt unit, the shutter lever needs to be
placed in the locked position so that the shutter lever will not interfere with the suction
transport unit.

• To prevent the toner collecting port shutter from leaving unopened after the installation of
the transfer belt unit, installing the waste toner box pushes the shutter lever of the toner
collecting port and opens the collecting port.

Locked Unlocked

magicolor 4650EN

magicolor 4650DN

Composition/Operation

Shutter lever

A011T2C035DA A011T2C036DA

43

14. Transfer section (2nd transfer) Theory of operation Ver.1.0 Nov. 2007

14. Transfer section (2nd transfer)

14.1 Composition

magicolor 4650EN

magicolor 4650DN

Composition/Operation

2nd transfer roller

Pre-transfer guide plate

A011T2C519AA

2nd transfer roller

A011T2C528AA

Retraction gear

44

A011T2C567AA

Theory of operation Ver. 1.0 Nov. 2007 14. Transfer section (2nd transfer)

14.2 Drive

2nd image transfer
pressure/retraction clutch (CL5)

A011T2C566AA

14.3 Operation

14.3.1 2nd transfer roller pressure mechanism

• The main body is provided with a mechanism that presses the 2nd transfer roller up
against, and retracts it from, the transfer belt. This is done to prevent the 2nd transfer
roller from being dirtied due to patterns produced for purposes other than an actual print­ing operation. Such patterns may be produced during the image stabilization sequence
or another function.

A. 2nd transfer roller pressure

• The 2nd transfer roller is pressed against the transfer belt to allow the toner image on the
transfer belt to be transferred onto the media.

• The 2nd transfer roller is pressed against the transfer belt to allow the roller to be
cleaned.

B. 2nd transfer roller retraction

• The 2nd transfer roller is retracted from the transfer belt when a detection pattern is pro­duced on the transfer belt for registration correction control, image stabilization control,
or other control.

• The 2nd transfer roller is retracted from the transfer belt after the 2nd transfer of the last
image is completed during a multi-print cycle.

magicolor 4650EN

magicolor 4650DN

Composition/Operation

45

14. Transfer section (2nd transfer) Theory of operation Ver.1.0 Nov. 2007

C. Pressure/retraction operation

1. Rotation of the Transport motor is transmitted to the drive roller of the intermediate
transfer belt unit.

2. Rotation of the drive roller is transmitted to the

magicolor 4650EN

magicolor 4650DN

3. When the

clutch

.

2nd image transfer pressure/retraction clutch is energized, the rotation is

transmitted to the pressure cam via a coupling gear.

2nd image transfer pressure/retraction

4. When the pressure cam turns a half turn, the 2nd transfer roller is pressed against
the transfer belt.

5. At the same time, the IDC sensor lever is pushed up to open the IDC sensor cover.

6. The light blocking plate fitted on the shaft of the pressure cam blocks the

transfer retraction position sensor

and a pressed position of the 2nd transfer roller is

detected.

7. When the

2nd image transfer pressure/retraction clutch is energized a second time, the

pressure cam is turned another half turn. The 2nd transfer roller to be retracted
from the transfer belt. At the same time, the IDC sensor lever is released, which
closes the IDC sensor cover.

8. The light blocking plate unblocks the

2nd image transfer retraction position sensor and a

retracted position of the 2nd transfer roller is detected.

2nd image transfer retraction position sensor (PS10)

2nd image

Retraction cam

Composition/Operation

2nd image transfer pressure/retraction clutch (CL5)

When retractedWhen pressed

2nd transfer roller

Retraction cam

A011T2C556AA

Retraction cam

Retraction gear

A011T2C568AA

A011T2C555AA

46

Theory of operation Ver. 1.0 Nov. 2007 14. Transfer section (2nd transfer)

14.3.2 2nd transfer voltage control

• The transfer voltage is applied to the 2nd transfer roller in order to transfer the toner
image from the transfer belt to the media.

• The transfer voltage is applied after the 2nd transfer roller has been pressed against the
transfer belt.

14.3.3 2nd transfer voltage setting control (ATVC: auto transfer voltage control)

• The transfer voltage is corrected to reduce effect from the transfer belt and environmen­tal changes of toner.

A. Operation timing

• A print request is accepted.

• During a multi-print cycle, the temperature inside the main body changes by a predeter­mined value or more from the level during execution of ATVC, and a predetermined num­ber of printed pages or more have been produced since the execution of the previous
AT VC .

B. Control

1. 1. The 2nd transfer roller is pressed against the transfer belt.

2. A constant current is applied to the 2nd transfer roller.

3. The voltage of the 2nd transfer roller surface is detected.

4. Using a conversion formula, the output value of the transfer voltage is determined.

5. The current temperature inside the main body is detected and backed up.

magicolor 4650EN

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Composition/Operation

47

14. Transfer section (2nd transfer) Theory of operation Ver.1.0 Nov. 2007

14.3.4 2nd transfer roller cleaning control

• DC positive and negative transfer bias voltages are alternately applied to the 2nd transfer
roller. This allows toner residue on the surface of the 2nd transfer roller to be transferred
back to the transfer belt, thus cleaning the 2nd transfer roller.

• Any voltage for other control purposes is not applied during the cleaning procedure.

magicolor 4650EN

• The toner transferred back to the transfer belt is collected by the cleaning blade.

magicolor 4650DN

2nd transfer roller

Cleaning blade

Transfer belt

4138to2579c0

A. Operation timing

• The power switch is turned ON.

• The 2nd transfer roller cleaning sequence is carried out after the intermediate transfer
belt has been cleaned during recovery from a media misfeed or malfunction.

• If 100 printed pages or more have been produced after the last cleaning sequence when
the printer completes a print cycle and is then brought to a stop, a new cleaning
sequence is carried out before the printer is brought to a stop.

• The cleaning sequence is carried out when a media size error occurs.

Composition/Operation

HV1

48

Theory of operation Ver. 1.0 Nov. 2007 15. Waste toner collecting section

15. Waste toner collecting section

15.1 Composition

magicolor 4650EN

magicolor 4650DN

K developing motor (M5)

Suction transport unit

A011T2C520AA

Waste toner transport unit

Toner collecting screw
(Print unit)

K

C

M

Y

Waste toner collecting bottle

A011T2C059DA

Composition/Operation

A011T2C559AA

49

15. Waste toner collecting section Theory of operation Ver.1.0 Nov. 2007

15.2 Drive

K developing motor (M5)

magicolor 4650EN

magicolor 4650DN

Waste toner collecting screw
(Waste toner transport unit)

Waste toner collecting screw
(Suction transport unit)

1st conveyance screw
(Waste toner bottle)

Composition/Operation

2nd conveyance screw
(Waste toner bottle)

A011T2C560AA

50

Theory of operation Ver. 1.0 Nov. 2007 15. Waste toner collecting section

15.3 Operation

15.3.1 Toner flow at the 1st transfer section

1. Toner scraped off by the cleaning blade in the print unit is conveyed to the toner col­lecting port by the toner collecting screw.

2. The waste toner conveyed to the toner collecting port is conveyed to the waste
toner transport unit.

3. The toner conveyed is carried to the suction transport unit by the transport roller
provided in the waste toner transport unit.

4. The conveyed toner is carried to the toner collecting port of the waste toner box by
the conveyance screw provided in the suction transport unit.

5. The toner conveyed is stored into in the waste toner box by the conveyance screw
provided in the waste toner box.

magicolor 4650EN

magicolor 4650DN

Waste toner collecting screw
(Waste toner transport unit)

Waste toner collecting screw
(Suction transport unit)

Toner collecting screw
(Print unit)

2nd conveyance screw
(Waste toner bottle)

C

M

Y

Composition/Operation

K

A011T2C561AA

51

15. Waste toner collecting section Theory of operation Ver.1.0 Nov. 2007

15.3.2 Toner flow at the 2nd transfer section

1. Toner scraped off by the cleaning blade provided in the transfer belt unit is collected
onto the middle of the transfer belt unit by the toner collecting screw.

2. The toner collected is conveyed to the suction transport unit through the toner col­lecting port that is provided in the middle of the transfer belt unit.

magicolor 4650EN

magicolor 4650DN

3. The conveyed toner is carried to the toner collecting port of the waste toner box by
the conveyance screw provided in the suction transport unit.

4. The toner conveyed is stored into in the waste toner box by the conveyance screw
provided in the waste toner box.

Waste toner collecting screw
(Transfer belt unit)

Composition/Operation

2nd conveyance screw

Waste toner collecting screw
(Suction transport unit)

1st conveyance screw (Waste toner bottle)

(Waste toner bottle)

A011T2C562AA

52

Theory of operation Ver. 1.0 Nov. 2007 15. Waste toner collecting section

15.3.3 Toner collecting port shutter mechanism at the suction transport unit

• A dual-shutter is used to prevent waste toner from being spilled from the toner collecting
port when the waste toner box is removed and reinstalled.

• Placing the box lock lever of the waste toner box in the “locked” position (the 9 o'clock
position) closes the first shutter of the toner collecting port.

• Removing the waste toner box closes the second shutter.

First shutter Second shutter

A011T2C042DAA011T2C041DA

magicolor 4650EN

magicolor 4650DN

15.3.4 Toner collecting port shutter mechanism of the waste toner bottle

• A shutter is used to prevent waste toner from being spilled from the toner collecting port
when the waste toner box is removed and reinstalled.

• Placing the box lock lever of the waste toner box in the “locked” position (the 9 o'clock
position) closes the shutter of the toner collecting port.

Collecting port

Box lock lever

Locked

Box lock lever

A011T2C044DAA011T2C043DA

Composition/Operation

53

15. Waste toner collecting section Theory of operation Ver.1.0 Nov. 2007

15.3.5 Waste toner box locking mechanism

• When the box lock lever is in the unlocked position (the 12 o'clock position), the protru­sion provided at the toner collecting port interferes with the main body frame, thus pre­venting the waste toner box from being removed.

• When the box lock lever is in the locked position (the 9 o'clock position), the waste toner

magicolor 4650EN

magicolor 4650DN

box can be removed.

Box lock lever

Collecting port

Locked

Protrusion

A011T2C045DA

15.3.6 Waste toner box locked position detection mechanism

• When the box lock lever is in the locked position (the 9 o'clock position), the protrusion

Composition/Operation

provided in the front door interferes with the box lock lever. As a result, the front door
cannot be closed.

• When the box lock lever is in the unlocked position (the 12 o'clock position), the front
door can be closed.

Lock Unlock

54

A011T2C046DA

Theory of operation Ver. 1.0 Nov. 2007 15. Waste toner collecting section

15.3.7 Waste toner box-in-position detection mechanism

• The waste toner box set detection lever is provided to detect a waste toner box loaded in
position.

• When the waste toner box is not loaded, the set detection lever lowers by its own weight
to plug the set detection window.

• The protrusion provided in the front door interferes with the set detection lever that plugs
the set detection window. Then, the front door cannot be closed.

• When the waste toner box is loaded in position, it pushes up the set detection lever to
uncover the set detection window.

magicolor 4650EN

magicolor 4650DN

Set detection
lever

Set detection
window

A011T2C047DA

15.3.8 Waste toner flow in the waste toner box

1. Toner conveyed to the toner collecting port is conveyed to the 2nd conveyance
screw by the 1st conveyance screw provided in the waste toner box.
he toner is conveyed into the waste toner box by the 2nd conveyance screw.

2. In order for waste toner to be accumulated from the left side, the waste toner box
has the dividing screens.

3. Waste toner conveyed to the rear end of the box is conveyed up to the detection
window by the agitating blade. When the waste toner conveyed to the detection
window blocks the waste toner sensor, the waste toner near full condition is
detected.

Top view

Waste toner sensor (PS11)

1st conveyance screw

2nd conveyance screw

Detection window

Agitating blade

Composition/Operation

Dividing screens

A011T2C048DA

55

15. Waste toner collecting section Theory of operation Ver.1.0 Nov. 2007

15.3.9 Waste toner near-full condition detection control

• A waste toner near-full condition is detected when the waste toner sensor continuously
blocks for a predetermined period of time.

• At this time, a waste toner near-full condition warning is given on the panel.

magicolor 4650EN

magicolor 4650DN

When the sensor is unblocked When the sensor is blocked

15.3.10 Waste toner full condition detection control

• A waste toner full condition is detected when the cumulative total number of print dots
(waste toner detection dot count) exceeds a predetermined value after a waste toner box
near-full condition has been detected.

• A waste toner full condition warning is given on the panel at this time.

• The main body accepts no print job after the waste toner full condition has been
detected.

• The waste toner full warning indication disappears when a new waste toner bottle is

Composition/Operation

installed.

Detection window

Waste toner sensor (PS11)

A011T2C049DA

56

Theory of operation Ver. 1.0 Nov. 2007 16. Media feed section (Tray 1)

16. Media feed section (Tray 1)

16.1 Composition

magicolor 4650EN

magicolor 4650DN

Feed roller

Separation roller

Transport motor (M3)

A011T2C521AA

Media lift plate

Tray1 media feed clutch (M2)

A011T2C529AA

Composition/Operation

A011T2C553AA

Feed roller

Tray1 media empty sensor

Separation roller

A011T2C554AA

57

16. Media feed section (Tray 1) Theory of operation Ver.1.0 Nov. 2007

16.2 Drive

Tray1 media feed clutch (CL2)

magicolor 4650EN

magicolor 4650DN

Transport motor (M3)

Feed roller

16.3 Operation

16.3.1 Media lift plate mechanism

• The media lift plate will be locked under the media lift plate lock lever by pressing it down
(in which the media is loaded in position). The media lift plate lock lever will be pressed to
the feed roller.

• The media feed clutch will rotate the feed roller to activate the lock release lever pressed
to the feed roller, and the media lift plate will be unlocked.

• The media lift plate (media stack) is pressed against the feed roller.

Composition/Operation

• The media lift plate (media stack) is pressed upward by the springs at all times.

A011T2C557AA

LOCK POSITION

Media lift plate lock lever

LOCK RELEASE POSITION

58

Feed roller

Media lift plate

Spring

4138to2617c0

Theory of operation Ver. 1.0 Nov. 2007 16. Media feed section (Tray 1)

16.3.2 Media separation mechanism

• Drive from the Transport motor is transmitted through the Tray1 media feed clutch to turn
the feed roller.

• The feed roller rotates to take up and feed media into the main body.

• Double-feeding of media is prevented by the separation roller provided with a torque lim­iter.

Feed roller

Separation
roller

4138to2618c0

magicolor 4650EN

magicolor 4650DN

16.3.3 Media feed control

• Drive from the transport motor is transmitted through the tray1 media feed clutch to turn
the feed roller, thereby taking up and feeding the media.

• The media taken up and fed in is conveyed onto the registration roller.

• The media is pressed against the stationary registration roller so that a loop is formed in
the media. The feed roller is then stopped. The loop thus formed in the media corrects
any mechanical skew in the media.

Composition/Operation

59

16. Media feed section (Tray 1) Theory of operation Ver.1.0 Nov. 2007

16.3.4 Media empty condition detection control

• A media empty condition is detected when the empty sensor actuator unblocks the tray1
media empty sensor.

• No mechanism is provided for detecting a media near-empty condition. The media sup­ply level indicator serves this purpose.

magicolor 4650EN

magicolor 4650DN

Composition/Operation

Actuator
(Tray1 media
empty sensor)

A011T2C577AA

60

Theory of operation Ver. 1.0 Nov. 2007 17. Media feed section (Tray 2)

17. Media feed section (Tray 2)

17.1 Composition

magicolor 4650EN

magicolor 4650DN

Trailing edge guide plate

Tray2 media feed clutch (CL1)

Tray2 set switch (SW5)

A011T2C522AA

Empty sensor actuator

Edge guide plate

Transport motor (M3)

A011T2C530AA

Feed roller

Separation
roller

A011T2C558AA

Tray2 media empty sensor (PS1)

Media level
indicator lever

A011T2C552AA

Composition/Operation

61

17. Media feed section (Tray 2) Theory of operation Ver.1.0 Nov. 2007

17.2 Drive

Transport motor (M3)

magicolor 4650EN

magicolor 4650DN

17.3 Operation

17.3.1 Media lift plate mechanism

• The media lift plate is pressed down into the locked position (in which the media is
loaded in position).

• Load a media stack and then slide the tray into the main body. This causes the lock

Composition/Operation

release lever to unlock the media lift plate.

• The media lift plate (media stack) is pressed against the feed roller.

• The media lift plate (media stack) is pressed upward by the springs at all times.

Tray2 media feed clutch (CL1)

Feed roller

A011T2C551AA

Media lift plate

Feed roller

62

Spring

4138to2605c0

Theory of operation Ver. 1.0 Nov. 2007 17. Media feed section (Tray 2)

17.3.2 Media separation mechanism

• Drive from the transport motor is transmitted through the tray2 media feed clutch to turn
the feed roller.

• The feed roller rotates to take up and feed media into the main body.

• Double-feeding of media is prevented by the separation roller provided with a torque lim­iter.

Feed roller

Separation
roller

4138to2089c0

magicolor 4650EN

magicolor 4650DN

17.3.3 Media feed control

• Drive from the transport motor is transmitted through the tray2 media feed clutch to turn
the feed roller, thereby taking up and feeding the media.

• The media taken up and fed in is conveyed onto the registration roller.

• The media is pressed against the stationary registration roller so that a loop is formed in
the media. The feed roller is then stopped. The loop thus formed in the media corrects
any mechanical skew in the media.

• As the trailing edge of the media reaches a point immediately before the feed roller, the
feed roller is stopped.

Composition/Operation

63

17. Media feed section (Tray 2) Theory of operation Ver.1.0 Nov. 2007

17.3.4 Media supply level detection control

• There is a window in the front cover of the cassette for indicating the media supply level.

• When the media lift plate goes up, a red lever appears in the window. The lower the level
of the media stack, the more the red portion is visible.

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magicolor 4650DN

17.3.5 Media empty condition detection control

• The media empty message “PAPER EMPTY TRAY2” is displayed on the panel when the
empty sensor actuator unblocks the media empty sensor.

• No mechanism is provided for detecting a media near-empty condition. The media sup­ply level indicator replaces this function.

Composition/Operation

When media
is loaded

A media empty
condition

Lever

Lever indicator indicating the media supply level

4138to2091c0

A011T2C563AA

Tray2 media empty sensor (PS1)

4138to2092c0

A media empty condition

When media is loaded

Empty sensor
actuator

64

Media lift plate

4138to2124c0

Theory of operation Ver. 1.0 Nov. 2007 17. Media feed section (Tray 2)

17.3.6 Tray open/close detection control

• Whether tray is opened or closed is detected with the tray 2 set switch.

1. Closing the tray will make the detecting plate press and turn ON the tray 2 set
switch mounted on the main body frame.

2. The switch will be OFF if the tray is pulled out, and “PAPER EMPTY TRAY 2” will
appear.

Tray2 set switch (S5)

Tray detection
plate

magicolor 4650EN

magicolor 4650DN

A011T2C564AA

Tray detection plate

A011T2C565AA

17.3.7 Media misfeed detection control

• If the registration sensor is not activated within a predetermined period of time after a
media feed sequence has been started, the main body determines that there is a media
misfeed. It then gives the message “PAPER EMPTY TRAY 2” on the panel.

• The media misfeed display can be reset by opening and closing any of the doors.

Composition/Operation

65