BROTHER MFC3100, MFC580 Service Manual

FACSIMILE EQUIPMENT

SERVICE MANUAL

MODEL: MFC3100C/MFC580

form or by any means without perm ission in writing from the publisher.

Specifications are subject to change without notice.

PREFACE

This publication is a Service Manual covering the specifications, construction, theory of operation, and maintenance of the Brother facsimile equipment. It includes information required for field troubleshooting and repair--disassembly, reassembly, and lubrication--so that service personnel will be able to understand equipment function, to rapidly repair the equipment and order any necessary spare parts.

To perform appropriate maintenance so that the facsimile equipment is always in best condition for the customer, the service personnel must adequately understand and apply this manual.

This manual is made up of six chapters and appendices.

CHAPTER 1 GENERAL DESCRIPTION CHAPTER 2 INSTALLATION CHAPTER 3 THEORY OF OPERATION CHAPTER 4 DISASSEMBLY/REASSEMBLY AND LUBRICATION CHAPTER 5 MAINTENANCE MODE CHAPTER 6 ERROR INDICATION AND TROUBLESHOOTING

Appendix 1. EEPROM Customizing Codes Appendix 2. Firmware Switches (WSW) Appendix 3. Circuit Diagrams

This manual describes the models and their versions to be destined for major countries. The specifications and functions are subject to change depending upon each destination.

CHAPTER

GENERAL DESCRIPTION

CHAPTER 1 GENERAL DESCRIPTION

CONTENTS

1.1 EQUIPMENT OUTLINE ...................................................................................................1-1

1.1.1 External Appearance and Weight ........................................................................1-1

1.1.2 Components.........................................................................................................1-1

1.2 SPECIFICATIONS............................................................................................................1-2

1.1 EQUIPMENT OUTLINE

1.1.1 External Appearance and Weight

The figure below shows the equipment appearance and approximate dimensions.

(H) 217 mm

8.5"

(W)

426 mm

16.8"

(including handset)

Weight: Machine proper Approx. 6.5 kg (14.3 lbs.)

In package Approx. 10.5 kg (23.2 lbs.)

1.1.2 Components

The equipment consists of the following major components:

(D)

342 mm

13.5"

1-1

1.2 SPECIFICATIONS

Model Name MFC 3100C

GENERAL

Print Engine Modem Speed (bps) Transmission Speed (sec.) ITU-T Group Coding Method Document/ Print Paper Width Document/ Print Paper Length Print Paper Margin (upper, lower, left, right) ADF (pages) LCD Columns LCD Line LCD Backlight Backup Clock Memory Backup Memory Capacity (physical) Optional Memory Dimensions w/o Carton (WxDxH) Dimensions w Carton (WxD xH) Weight w/ o Carton Weight w Ca rton Color

Operating Environment Temperat ure Humidity

Power Source Power Consumption (Standby/Peak) On/Off Switch

TELEPHONE

Handset One-Touch Dial Speed Dial Speaker Phone Chain Dialing Caller ID Call Waiting Caller ID Distinctive Ringing Hold/Mute Key Hook Key Power Failure Dialing Speaker Volume Ring Volume Handset Volume

FAX

Scan Speed (A4:Standard) Memory Transmission (Brother#1 Chart) Memory Transmission (ITU-T Chart) Out-of-Paper Reception (Brother #1 Chart) Out-of-Paper Reception (ITU-T Chart) Color FAX (Document Send/Receive) Color FAX (Memory Send/Receive)

INTERFACE

External TAD Interface Host Interface (IEEE1284) Host Interface (USB) LAN Interfa c e

Ink Jet (BH 2-head)

14,400 (Fax)

6 (Brother#1,MMR)

MH/MR/MMR/JPEG

3.5"-8.5"/3.5"-8.5"

5.0"-14"/5.0"-14"

0.12, 0.43, 0.12, 0.12 inch (3,11, 3, 3 mm) Up to 20

16 characters

Single line

Yes

N/A

2MB (RAM)

16.8"x13.5"x8.5" (426x342x217 mm)

20.4"x18.0"x14.8" (517x458x375 mm)

6.5kg/14.3lbs

10.5 kg/23.2lbs Gray 1495

5 - 35 degrees Centigrade

60% +-25%

120VAC 50/60Hz

Under 7W/35W

No No

Max. 40

Yes

No No

Yes

No No No No

Yes (2 steps + OFF)

Approx. 5 sec./page (A4:standard)

Yes (100:MMR)

Yes (85:MMR)

Yes (100:MMR)

Yes (85:MMR)

Yes/Yes

No/Yes

Yes Yes Yes

1-2

Model Name MFC 3100C

PRINTER

Color/Mono Engine Type Resolution (dpi)

Piezo Ink Jet (2-head BH: 75 nozzles/color)

1200x1200 /2400x1200 (Mono/Color)

Color/Mono

10/8 (Mono/Color: 600*150)

Speed (ppm)

'4/3.5 (Mono/Color: 600*300) '2/1.5 (Mono/Color: 600*600)

'0.2/0.2 (Mono/Color: 1200*1200/2400*1200)

Paper Capacity (sheets) Output Paper Capacit y (sheets) Standard Print Language Emulation Resident Fonts Fonts Disk Based Paper Handling Size Manual Feed Slot Other Paper Type

Sheet Weight (Paper Cassette) (Manual Slot)

Printer Driver

COPY

Color/Mono Speed (cpm) Multi Copy(Stack) Multi Copy (Sort) Resolution (dpi)

SCANNER

Color/Mono Resolution (dpi) (Phys i cal) Resolution (dpi) (Logical) Speed (ppm) Gray Scale

TWAIN Compliant & Operating System

PCI Scanner (Parallel/Serial)

ACCESSORY

Cartridge Life / Yield (Normal, 5% Coverage)

LTR, LGL, A4, B5 , A5, EXE, Post Card

64-120 g/m2 (17 - 32 lb)

Win95/98/98SE/Me/2000Professional/NT4.0/

Yes (B&W only) or Via PC

Max. 1200x1200 (color)

Win95/98/98SE/2000Professional/NT4.0/Me

4 colors (each separate tank)

Black: 950, Color: 450

100

Windows GDI

No Yes Yes

N/A

OHP, Envelopes

N/A

MacOS 8.5-9.1

Color/Mono

7/4

N/A or Via PC

Color/Mono

CIS: 300x600 (Opt.)

2400 (Int.)

Max. 5sec

256

MacOS 8.6-9.1

Parallel/USB

1-3

Model Name MFC-580

)

GENERAL

Print Engine Modem Speed (bps) Transmission Speed (sec.) ITU-T Group Coding Method Document/Print Paper Width Document/Print Paper Length Print Paper Margin (upper, lower, left, right ADF (pages) LCD Colums LCD Line LCD Backlight Backup Clock Memory Backup Memory Capacity (Physical) Optional Memory Dimensions w/o Carton (WxDxH) Dimensions w Carton (WxDxH) Weight w/o Carton Weight w Car ton Color Operating Environment Temperature

Humidity Power Source

Power Consumption (Standby/Peak) On/Off Switch

TELEPHONE

Handset One-Touch Dial Speed Dial Speaker Phone Chain Dialing Caller ID Call Waiting Caller ID Distinctive Ringing Hold/Mute Key Hook Key (Tel key) Power Failure Dialing Speaker Volume Ring Volume HandSet Volume

FAX

Scan Speed (A4:Standard) Memory Transmission (Brother#1 Chart) Memory Transmission (ITU-T Chart)

Out-of-Paper Reception (Brother #1 Chart) Out-of-Paper Reception (ITU-T Chart)

Color FAX (Document Send/Receive) Color FAX (Memory Send/Receive)

INTERFACE

External TAD Interface Host Interface (IEEE1284) Host Interface (USB) LAN Interface No

0.12, 0.43, 0.12, 0.12 inch (3,11, 3, 3 mm)

16.8"x13.5"x8.5" (426x342x217 mm)

20.4"x18.0"x14.8" (517x458x375 mm)

Ink Jet (BH 2-head)

14,400 (Fax)

6(Brother#1,MMR)

MH/MR/MMR/JPEG

90-216/90-216mm

127-356/127-356mm

Up to 20

16 characters

1 Line

N/A

Yes (1 hour)

N/A

2MB as spec.(Actually 8MB)

6.5kg/14.3lbs

10.5 kg/23.2lbs Gray 1495

5 - 35 degrees Centigrade

60% +-25%

240VAC 50/60Hz

Under 6W/35W

N/A N/A

Yes

No No

Yes (only for UK, Denmark)

Tel (for F/T switch)

No No

Yes (2 steps + OFF)

Approx. 5 sec./page (A4:standard)

Yes (100:MMR)

Yes (85:MMR)

Yes (100:MMR)

Yes (85:MMR)

Yes/Yes

No/Yes

Yes Yes Yes

1-4

Model Name M FC-580

PRINTER

Color/Mono Engine Type Resolution (dpi)

Piezo Ink Jet (2-head BH: 75 nozzles/colour)

1200x1200/2400x1200 (B&W/Colour)

Color/Mono

10/8 (Mono/Color: 600*150)

'4/3.5 (Mono/Color: 600*300)

Speed(ppm)

'2/1.5 (Mono/Color: 600*600)

'0.2/0.2 (Mono/Color:

1200*1200/2400*1200)

Paper Capacity (sheets) Output Paper Capacity (sheets) Standard Print Language Emulation Resident Fonts Fonts Disk Based

Paper Handling Size

Manual Feed Slot Other Paper Type Sheet Weight (Paper Cassette)

(Manual Slot)

Printer Driver

COPY

Color/Mono Speed (ppm) Multi Copy (Stack) Multi Copy (Sort) Resolution (dpi)

SCANNER

Color/Mono Resolution (dpi) (Physica l ) Resolution (dpi) (Logical) Speed (ppm) Gray Scale

TWAIN Compliant & Operating System

PCI Scanner (Parallel/Serial)

ACCESSORY

Cartridge Life / Yield (Draft, 5% Coverage)

LTR, LGL, A4, B5, A5, EXE,

Photo card, Index card

64-105 g/m2 (17 - 28 lb)

Win95/98/98SE/Me/2000Professional/NT4.0/

Yes (B&W only) or Via PC

Win95/98/98SE/2000Professional/NT4.0/Me

4 colours (each separate tank)

Black: 950, Color: 450

100

Windows GDI

N/A

Yes Yes

N/A

OHP, Envelopes

N/A

MacOS 8.5-9.1

Color/Mono

7/4

N/A or Via PC

Max. 1200x1200

Color/Mono

CIS: 300x600 (Opt.)

2400 (Int.) Max. 5sec

256

MacOS 8.6-9.1

Parallel/ USB

1-5

CHAPTER

INSTALLATION

CHAPTER 2 INSTALLATION

CONTENTS

2.1 INSTALLING THE UPDATE DATA TO THE FACSIMILE MACHINE.............................2-1

2.2 SETTING ID CODES TO FACSIMILE MACHINES CONNECTED TO A SINGLE

PC VIA THE USB PORT..................................................................................................2-3

2.3 SETTING HEAD PROPERTY TO THE FACSIMILE MACHINE .....................................2-4

2.1 INSTALLING THE UPDATE DATA TO THE

FACSIMILE MACHINE

If the program version is updated or the main PCB is replaced, then install the update program onto the flash ROM of the main PCB.

The program installation requires a PC/AT-compatible computer (which is capable of running MSDOS or its compatible OS).

Connecting the facsimile machine to your PC

(1) Make sure that your PC is turned off. (2) Make sure that the machine's power cord is unplugged from a wall socket. (3) Connect the parallel interface cable to the parallel port on the back of the machine and secure

it with the lock wires.

(4) Connect the other end of the interface cable to the printer port of your PC and secure it with

two screws.

(5) While pressing the 5 key on the machine's control panel, plug the machine's power cord into a

wall socket.

(6) Check to see that the following pattern displays on the LCD. If it does not display, go back to

step (2) above.

(7) Turn on your PC.

Parallel interface cable

Lock wires

Host compute

2-1

Installing the update data onto the flash ROM of the facsimile machine

NOTE: The following is an installation procedure example on a PC that is running Windows 95/98.

(1) Copy the update data and transfer utility onto the desired directory of the hard disk.

e.g., C:\UPDATE

(2) Click the Start button, point to Programs, and then click MS-DOS Prompt to open an MS-DOS

window.

(3) Type the drive letter where the update data and transfer utility are located. In the above

example, type C:\ from the command line and press the ENTER key. Then type CD UPDATE and press the ENTER key.

(4) Check that your PC is connected with the facsimile machine correctly. (5) To start the transfer utility transmitting the update data to the flash ROM of the facsimile

machine, type the following:

ICEN filename /b

Then press the ENTER key. During downloading, the machine beeps intermittently. Upon completion of the downloading, the machine beeps continuously.

NOTE: If the facsimile machine cannot return to the standby state af ter completion of downloading, turn the power off and on.

2-2

2.2 SETTING ID CODES TO FACSIMILE MACHINES CONNECTED TO A SINGLE PC VIA THE USB PORT



 Function



Brother facsimile machines are assigned unique ID codes (character strings) at the factory. If you replace the main PCB of the machine, the machine will lose its assigned ID code so that it will not be identified by the connected PC.

To connect those machines to a PC via USB, you need to assign ID codes (character strings) to those individual machines according to the procedure given here. For models covered by this manual, set serial numbers given to individual machines as ID codes.



 Connecting each of facsimile machines to your PC



(1) Make sure that your PC is turned off. (2) Make sure that the machine's power cord is unplugged from a wall socket or other power

source.

(3) Connect the interface cable to the parallel interface port on the back of the facsimile machine

and secure it with the lock wires.

(4) Connect the other end of the interface cable to the printer port of your PC and secure it with

the two screws. (5) Plug the machine's power cord into a wall socket or other power source. (6) Turn on your PC.



 Operating Procedure



(1) On your PC, run the ID setup utility. Follow the instructions shown on the PC's screen and

enter the 9-digit serial number (e.g., G01012345) printed on the nameplate labeled to the back

of the facsimile machine as an ID code. Then press the Enter key.

The ID setting utility will transmit the ID code data from your PC to the facsimile machine

and then it will terminate.

The facsimile machine will automatically return to the standby mode. (2) To check whether the entered character string (ID code) is correct, make the machine enter the

maintenance mode (refer to CHAPTER 5, Section 5.1) and then press the 1 key twice

(Subsection 5.3.5).

The facsimile machine will print out a Configuration List. At the right top of the list, "SER.#:

BROXXXXXXXXX" is printed. (3) Check that the character string entered in step (2) is printed in "XXXXXXXXX."

If it is OK, press the 9 key twice to exit from the maintenance mode.

If something other than that is printed in XXXXXXXXX, check the connection between the

PC and facsimile machine and go back to step (1).

2-3

2.3 SETTING HEAD PROPERTY TO THE FACSIMILE MACHINE



 Function



To keep the print quality, the controller optimizes the head drive strength, ink jet-out timing, and other drive conditions depending upon the electromechanical properties unique to the individual print head and ambient temperature. For that, the controller reads the head property information stored in the EEPROM of the main PCB.

If you replace the print head unit and/or main PCB of the machine, then you need to update the head property according to the procedure given here.



 Connecting the facsimile machine to your PC



(1) Make sure that your PC is turned off. (2) Make sure that the machine's power cord is unplugged from a wall socket or other power

source.

(3) Connect the interface cable to the parallel interface port on the back of the facsimile machine

and secure it with the lock wires.

(4) Connect the other end of the interface cable to the printer port of your PC and secure it with

two screws. (5) Plug the machine's power cord into a wall socket or other power source. (6) Turn on your PC.



 Operating Procedure



(1) On your PC, run the head property setup utility. Follow the instructions shown on the PC's

screen and enter upper 12 digits (e.g., 55557B657031) out of the 13-digit property code

(enclosed with asterisks, e.g., *55557B657031H*) which is printed on the bar code label

attached to the print head unit.

The utility will transmit the head property from your PC to the facsimile machine and then it

will terminate.

The facsimile machine will automatically return to the standby mode. (2) To check whether the entered head property is correct, make the machine enter the

maintenance mode (refer to CHAPTER 5, Section 5.1) and then press the 7 key twice

(Subsection 5.3.15).

The facsimile machine will print out the Equipment's Log. On the line about 1/3 of full length

of the log sheet below from the top, the 12-digit code is printed. (3) Check that the character string entered in step (2) is printed in "XXXXXXXXXXXX."

If it is OK, press the 9 key twice to exit from the maintenance mode.

If something other than that is printed in XXXXXXXXXXXX, check the connection between

the PC and facsimile machine and go back to step (1).

2-4

CHAPTER

THEORY OF OPERATION

CHAPTER 3 THEORY OF OPERATION

CONTENTS

3.1 OVERVIEW ......................................................................................................................3-1

3.2 MECHANISMS.................................................................................................................3-2

3.2.1 Scanner Mechanism ............................................................................................3-3

3.2.1.1 Document feeding and ejecting mechanism................................................3-3

3.2.1.2 Scanner........................................................................................................3-3

3.2.2 Ink Jet Printing Mechanism..................................................................................3-4

3.2.2.1 Paper pulling-in, registration, feeding, and ejecting mechanisms................3-4

3.2.2.2 Ink jet printing and capping mechanisms.....................................................3-6

3.2.2.3 Purging mechanism .....................................................................................3-9

3.2.2.4 Carriage drive mechanism .........................................................................3-12

3.2.3 Sensors and Actuators.......................................................................................3-13

3.3 CONTROL ELECTRONICS...........................................................................................3-16

3.3.1 Configuration......................................................................................................3-16

3.1 OVERVIEW

3-1

3.2 MECHANISMS

The facsimile machine is classified into the following mechanisms:

 SCANNER MECHANISM - Document feeding and ejecting mechanism

 INK JET PRINTING MECHANISM - Paper pulling-in, registration, feeding, and ejecting

 SENSORS AND ACTUATORS

- Document scanning mechanism

mechanisms

- Ink jet printing and head capping mechanisms

- Purging mechanism

- Carriage drive mechanism

Document feeding and ejecting mechanism

Document scanning mechanism

Ink jet pri nting and head capping mechanisms

Purge mechanism Carriage drive mechanism

Paper pulling-in, registration, feeding, and ejecting mechanisms

SCANNER MECHANISM

INK JET PRINTING MECHANISM

3-2

3.2.1 Scanner Mechanism

3.2.1.1 Document feeding and ejecting mechanism

This mechanism consists of the document stacker, automatic document feeder (ADF), document feed roller ASSY, document ejection roller ASSY, and document sensors. (For details about the sensors, refer to Subsection 3.2.3.)

If you set documents on the document stacker with their faces down and start the scanning operation, then the scanner motor rotates so that the ADF (which consists of the separation roller and ADF parts) feeds those documents into the machine, starting from the bottom sheet (first page) to the top (last page), page by page. Each document advances with the document feed roller ASSY to the scanner, and then it is fed out of the machine with the document ejection roller ASSY.

3.2.1.2 Scanner

The scanner uses a contact image sensor (CIS) unit which consists of an LED array illuminating documents, a self-focus lens array collecting the reflected light, a CIS PCB carrying out photoelectric conversion to output picture element data, and a cover glass on which a document advances. When the document passes between the document pressure bar and the cover glass, it is scanned.

3-3

3.2.2 Ink Jet Printing Mechanism

3.2.2.1 Paper pulling-in, registration, feeding, and ejecting mechanisms

The paper pulling-in, registration, feeding, and ejecting mechanisms are driven by a single paper feed motor located at the left side of the main chassis via the gear train. (See the illustration given on the next page.)

First, the paper feed motor rotates clockwise (when viewed from the output gear). The rotation is transmitted to the PF roller gear that rotates paper feed roller. At the right end of the paper feed roller is the PF roller gear R which is always engaged with the ASF/purge idle gear. Engaged with the ASF/purge idle gear, the ASF-purge switching gear 23 transmits the rotation via gear 25 and the ASF gear train to the ASF roller unit. This way, the ASF roller will pull in paper.

When the ASF roller is pulling in paper, the paper feed roller rotates in the backward direction to register the leading edge of the pulled-in paper.

Next, the paper feed motor rotates counterclockwise to rotate the paper feed roller in the forward direction. The paper will advance through the paper path. During the paper feeding operation, no rotation is transmitted to the ASF roller because of the planetary gear system built in the ASF roller unit.

The above paper pulling-in and feeding operations take place when the carriage is in printing operation. If the carriage reaches the purge position, the ASF-purge switching gear 23 will be disengaged from the gear 25 and engaged with purge bevel gear A. For the purging mechanism, refer to Subsection 3.2.2.3.

3-4

3-5

3.2.2.2 Ink jet printing and capping mechanisms

(1) Print head unit

This machine uses drop-on-demand ink jet printing. Each of the right and left print heads has an ink-jet unit that has a pair of nozzle columns for two color inks. A nozzle column consists of 75 nozzles, 75 channels covered with piezoelectric ceramic (PZT), a manifold, and filter. As illustrated below, the pair of nozzle columns is staggered.

Nozzle Layout (viewed from the bottom)

3-6

If the controller issues a print command, a biased voltage will be applied to all electrodes formed on the surface of the piezoelectric ceramic so that each actuator will be distorted as shown with broken lines.

If the electrodes on a target channel are deenergized according to drive signals, then the associated piezoelectric ceramic actuator returns to the previous form so that the ink in the manifold will be vacuumed out to the channel.

If the voltage is applied again, the piezoelectric ceramic actuator will be distorted again to apply pressure to the ink in the channel, causing the ink to jet out through the nozzle. The jetted-out ink drop will be splashed and produce a dot on paper held by the platen.

As the carriage holding the print head unit travels at the printing speed, the controller sends print command pulses to the piezoelectric actuator driver circuit embedded in the print head unit.

(2) Ink cartridges

The machine uses four ink cartridges (black, cyan, yellow, and magenta) of disposable type to supply ink to the print head unit. As shown below, an ink cartridge contains an ink-impregnated urethane foam. If ink-jet print operation or purging operation takes place, ink comes out of the urethane foam and is supplied to the print head unit through the ink room, filters, and manifold.

For the ink cartridge sensors on the carriage PCB, refer to Subsection 3.2.3.

3-7

(3) Head cap

Shown below is a head cap mechanism that prevents the nozzles of the print heads from drying up when they are not in use.

Upon completion of printing, the carriage travels to the right and moves the head cap holder provided on the purge unit to the right together. In the head cap holder is a head cap which is supported with a lift lever. The rightward movement of the head cap holder turns the lift lever and pushes up the head cap to the position where the head cap comes into tight contact with the print heads. This way, the nozzles will be capped.

3-8

3.2.2.3 Purging mechanism

The purge mechanism is driven by the paper feed motor located at the left side of the main chassis. As described in Subsection 3.2.2.1, the motor rotation is transmitted to the ASF/purge idle gear at

the right side of the main chassis. Engaged with the ASF/purge idle gear, the ASF-purge switching gear 23 works as a clutch gear.

When the carriage travels from the left to right to reach the purge position, the tab provided on the back of the carriage pushes the purge lever on the main chassis to the right (see the illustration below). Accordingly, the ASF-purge switching gear 23 (which was shifted to the left by the purge lever) will move to the right by the switching gear spring so as to become disengaged from the gear 25 and engaged with the purge bevel gear A. (See the illustration given on the next page.) This engagement will transmit the motor rotation to the purge bevel gear B on the purge unit. This way, when the carriage is in the purge position, the motor rotation is transmitted to the purge unit.

On the contrary, if the carriage travels from the purge position to the left, the tab on the back of the carriage releases the purge lever which will be pulled back to the left. The ASF-purge switching gear 23 will be disengaged from the purge bevel gear A.

3-9

During printing: The ASF-purge switching gear 23 is not engaged with pur ge bevel gear A ( but engaged with gear 25 in the ASF gear train).

During purging: T he ASF-purge switching gear 23 is engaged with purge bevel gear A.

When the motor rotation is transmitted to the purge unit, its counterclockwise rotation will drive the purge cam and its clockwise rotation, the pump switching unit (when viewed from the output gear of the motor).

When the paper feed motor rotates counterclockwise

When the paper feed motor rotates clockwise

3-10

The purge cam is so designed that:

- the carriage lock pops out to lock the carriage before purging and pops in before cleaning with

the head wiper (see the illustration below),

- the pump works to draw out ink from each of the four head nozzles and drain it to the ink

absorber felts, and

- the head wiper comes out to clean the nozzle surface (see the illustration below). The pump switching cam is so designed that:

- the pump switching unit switches application of the pump's negative pressure between the four

head nozzles in the order of black, cyan, yellow, and magenta nozzles. When the pump switching cam is in the home position, normal atmospheric pressure will be restored.

The home position of the purge cam and pump switching cam are detected by their HP switches. For those switches, refer to Subsection 3.2.3.

(1) Carriage lock

If the purge cam is driven, the carriage lock of the purge unit pops out and locks the carriage to align ink-jet unit with the mating purge caps during purge operation. After purging but before cleaning with the head wiper, it pops in to release the carriages. When the power is off, the carriage lock keeps the print heads pressed against the head caps.

(2) Purging

If activated, the pump draws out ink to purge air bubbles or dust from the inside of the head nozzles and channels. As the purge cam rotates by one turn, the piston of the pump reciprocates two strokes. To complete purging of all four nozzles and channels, the purge cam rotates by two turns ad the piston reciprocates four strokes.

(3) Draining

The pump drains drawn ink into the ink absorber felts.

(4) Cleaning with the head wiper

After purging operation, the head wiper comes out and the carriage moves from the right to left so as to clean ink remaining on the heads' surface.

(5) Restoring the pump's pressure to normal atmospheric pressure

When the pump switching cam is in the home position, the controller stops to produce negative pressure and restore the pump's pressure to normal atmospheric pressure.

3-11

3.2.2.4 Carriage drive mechanism

The carriage motor controls horizontal motion. The motor rotation is transmitted via the motor pulley to the timing belt.

The carriage, which is supported and guided by the carriage rail, is secured to the timing belt. Clockwise and counterclockwise rotations of the carriage motor move the carriage to the right and left, respectively.

On the back of the carriage is the carriage encoder which tells the control circuitry the current carriage position counted based on the carriage motor position by using the encoder strip attached to the main chassis.

3-12

+ 168 hidden pages