Ricoh is450 Service Manual
HS2P
(Machine Code: G407/G408/G410/G411)
Service Manual
Issued on 22nd December 1998
Ricoh Co., Ltd
IMPORTANT SAFETY NOTICES
1. Before disassembling or assembling parts of the scanner and peripherals,
make sure that the scanner power cord is unplugged.
2. The wall outlet should be near the scanner and easily accessible.
3. The output voltage of the PSU (Power Supply Unit) can be either 100 ~ 120
Vac or 220 ~ 240 Vac, without any adjustment. Make sure that the above
voltage is used.
4. The power cord should be an approved type, in accordance with the
regulations for the country in which the scanner is used.
5. The use of cables other than the shield I/O cables or equivalent specified will
invalidate the certification of this scanner and may cause interference levels
which exceed the limits established for this equipment.
Maintenance Information
The user’s manual explains how to use and maintain the scanner. Before
performing the maintenance, read the user’s manual.
Warning concerning copyright
Many documents are copyrighted. Such documents may not be reproduced by
scanning or in any other form without the express permission of the copyright
holder.
Notice
The contents of this manual are subject to change without notice.
TABLE OF CONTENTS
1. OVERALL MACH INE INFORMATION ........................................1-1
1.1 SPECIFICATIONS..................................................................................... 1-1
1.1.1 MAIN BODY......................................................................................1-1
1.1.2 ENDORSER .....................................................................................1-2
1.2 COMPONENT LAYOUT............................................................................1-3
1.2.1 FRONT VIEW...................................................................................1-3
1.2.2 REAR VIEW......................................................................................1-4
1.2.3 ADF ..................................................................................................1-5
1.3 DRIVE LAYOUT........................................................................................1-6
1.3.1 SCANNER........................................................................................1-6
1.3.2 ADF ..................................................................................................1-7
1.4 ELECTRICAL COMPONENT LAYOUT.....................................................1-8
1.4.1 SCANNER........................................................................................1-8
1.4.2 ADF ..................................................................................................1-9
2. DETAILED SECTION DESCRIPTIONS.......................................2-1
2.1 INITIALIZATION........................................................................................2-1
2.2 SCANNER MECHANISMS........................................................................2-3
2.2.1 BOOK MODE....................................................................................2-3
2.2.2 ADF MODE.......................................................................................2-7
2.3 PAPER MISFEED DETECTION..............................................................2-14
2.4 IMAGE PROCESSING............................................................................2-16
2.4.1 OVERVIEW ....................................................................................2-16
2.4.2 SBU................................................................................................2-17
2.4.3 IPU (IMAGE PROCESSING UNIT).................................................2-18
2.5 REVERSE SIDE SCANNING..................................................................2-21
2.5.1 OVERVIEW ....................................................................................2-21
2.5.2 CIS (CONTACT IMAGE SENSOR) UNIT.......................................2-22
2.5.3 IMAGE SCANNING........................................................................2-23
2.6 ENDORSER UNIT...................................................................................2-24
2.6.1 OVERVIEW ....................................................................................2-24
2.6.2 ENDORSER UNIT..........................................................................2-25
2.7 LOW POWER MODE..............................................................................2-26
2.8 MAIN PCBs AND THEIR FUNCTIONS ...................................................2-27
2.8.1 BOARD STRUCTURE....................................................................2-27
2.8.2 SCU (SCANNER CONTROL UNIT) ...............................................2-28
2.8.3 IOB (INPUT/OUTPUT BOARD)...................................................... 2-29
2.8.4 ADU (ADF DRIVE UNIT) ................................................................2-30
i
3. INSTALLA TION...........................................................................3-1
3.1 ENVIRONMENT........................................................................................3-1
3.1.1 PRECAUTIONS................................................................................3-1
3.1.2 ENVIRONMENTAL CONDITIONS ...................................................3-1
3.1.3 MACHINE LEVEL.............................................................................3-1
3.1.4 MINIMUM SPACE REQUIREMENTS...............................................3-1
3.1.5 POWER REQUIREMENTS ..............................................................3-2
3.2 SCANNER INSTALLATION.......................................................................3-2
3.3 IPU UNIT INSTALLATION.........................................................................3-2
3.4 ENDORSER UNIT INSTALLATION...........................................................3-3
3.4.1 ACCESSORY CHECK......................................................................3-3
3.4.2 INSTALLATION PROCEDURE ........................................................3-4
3.4.3 STAMP DENSITY ADJUSTMENT PROCEDURE............................3-6
3.5 RED LAMP UNIT INSTALLATION.............................................................3-7
3.5.1 ACCESSORY CHECK......................................................................3-7
3.5.2 INSTALLATION PROCEDURE ........................................................3-8
4. SERVICE LEVEL FUNCTIONS...................................................4-1
4.1 DIP SWITCH SETTINGS...........................................................................4-1
4.2 LEDs/TEST POINTS.................................................................................4-6
4.2.1 LEDs.................................................................................................4-6
4.2.2 TEST POINTS..................................................................................4-6
4.3 SPECIAL TOOLS ......................................................................................4-6
5. REPLACEMENT AND ADJUSTMENT........................................5-1
5.1 COVERS ...................................................................................................5-1
5.1.1 ADF EXTERIOR...............................................................................5-1
5.1.2 ADF COVER.....................................................................................5-2
5.1.3 SCANNER EXTERIOR/OPERATION PANEL..................................5-3
5.2 ADF AND UPPER SIDE............................................................................5-4
5.2.1 DOCUMENT SENSOR.....................................................................5-4
5.2.2 SEPARATION UNIT.........................................................................5-4
5.2.3 DOCUMENT TABLE ASSEMBLY ....................................................5-5
5.2.4 CIS....................................................................................................5-5
5.2.5 SCANNING GUIDE PLATE..............................................................5-6
5.2.6 FEED SENSOR................................................................................5-6
5.2.7 READ SENSOR................................................................................5-7
5.2.8 FEED-OUT SENSOR.......................................................................5-7
5.2.9 PAPER TRANSPORT DRUM...........................................................5-8
5.3 ADF AND RIGHT SIDE .............................................................................5-9
5.3.1 PAPER FEED MOTOR.....................................................................5-9
5.3.2 EDU..................................................................................................5-9
5.3.3 ENDORSER SOLENOID................................................................5-10
5.3.4 RELAY SENSOR............................................................................5-10
5.4 ADF AND LEFT SIDE..............................................................................5-11
5.4.1 ADU/PAPER TRANSPORT MOTOR..............................................5-11
ii
5.4.2 DOCUMENT TABLE POSITION SENSOR.....................................5-11
5.4.3 PICK-UP CLUTCH/DOCUMENT TABLE LIFT CLUTCH................5-12
5.5 SCANNER...............................................................................................5-13
5.5.1 EXPOSURE GLASS.......................................................................5-13
5.5.2 EXPOSURE LAMP.........................................................................5-14
5.5.3 SBU/LAMP STABILIZER/SCANNER MOTOR/PSU.......................5-15
5.5.4 IOB .................................................................................................5-16
5.5.5 SOP................................................................................................5-17
5.5.6 HOME POSITION SENSOR...........................................................5-17
5.5.7 ADF INTERLOCK SWITCH............................................................5-18
5.5.8 SCANNER WIRE............................................................................5-19
5.6 PCB.........................................................................................................5-22
5.6.1 SCU/RCU/IPU ................................................................................5-22
6. TROUBLESHOOTIN G.................................................................6-1
6.1 SELF-DIAGNOSTICS................................................................................6-1
6.2 CHECK ITEMS..........................................................................................6-1
6.2.1 ITEMS CHECKED DURING INITIALIZATION..................................6-1
6.3 ERROR INDICATION................................................................................6-2
6.3.1 USER LEVEL ERROR INDICATION................................................6-2
6.3.2 TECHNICIAN LEVEL ERROR INDICATION....................................6-2
6.4 TROUBLESHOOTING PROCEDURES....................................................6-3
6.4.1 USER-VISIBLE ERROR CONDITIONS............................................6-3
6.4.2 SERVICE CALL ERRORS (SYSTEM ERRORS) .............................6-8
6.5 INDICATION WHEN A CONNECTOR IS OUT OF POSITION................6-14
6.5.1 SCANNER......................................................................................6-14
6.5.2 ADF ................................................................................................6-15
6.6 BLOWN FUSE CODITIONS....................................................................6-16
7. OPTION.......................................................................................7-1
7.1 IPU (IMAGE PROCESSING UNIT)............................................................7-1
7.1.1 OVERVIEW ......................................................................................7-1
7.2 IMAGE PROCESSING PATH....................................................................7-2
iii
22 December 1998 SPECIFICATIONS
1. OVERALL MACHINE INFORMATION
1.1 SPECIFICATIONS
1.1.1 MAIN BODY
Scanning method: Flat-bed with ADF
Book scan: Horizontal: Max. 298 mm [11.7"]
Vertical: Max. 432 mm [17.0"]
ADF: Document size:
Width: 69 ~ 298 mm [2.7" ~ 11.7"]
Length: 120 ~ 2,000 mm [4.7" ~ 78.5"]
All pages in a document must be the
same width
Document weight: 41 ~ 128 g/m2 [11 ~ 34 lb.]
ADF capacity:
150 sheets (64 g/m2 [20 lb.])
110 sheets (105 g/m2 [24 lb.]/A4, A5, LT, HLT)
80 sheets (105 g/m2 [24 lb.]/A3, DLT)
Stack height must be less than 15 mm [0.6"]
Scanning resolution: Simplex mode:
Main scan: 100 ~ 800 dpi (in 1 dpi steps)
Sub scan: 100 ~ 800 dpi (in 1 dpi steps)
Duplex mode:
Main scan: 100 ~ 600 dpi (in 100 dpi steps)
Sub scan: 100 ~ 600 dpi (in 100 dpi steps)
Overall
Information
Grayscales: 8 bits/pixel
Initialization time: About 15 seconds
Scanning speed: 0.65 s/200 dpi (A4, binary picture mode)
Scanning throughput: Simplex mode: 55 ppm/200 dpi
(A4, binary picture mode)
Duplex mode: 86 ipm/200 dpi
(A4, binary picture mode)
(Counted from the second page)
Interface: SCSI-2
Power: 1) 102 to 138 V ac (45 to 65 Hz)
2) 187 to 276 V ac (45 to 65 Hz)
Power consumption
(without all possible options):
Simplex model Standby: 50 W Max.
Scanning: 90 W Max.
Low power mode: 12 W Max.
Duplex model Standby: 80 W Max.
Scanning: 120 W Max.
Low power mode: 12 W Max.
1-1
SPECIFICATIONS 22 December 1998
Operating environment:
Temperature: 10 to 32°C [50 to 90°F]
Humidity: 20 to 80% RH
Weight: Simplex Model: Less than 25 kg [55.1 lb.]
Duplex Model: Less than 26 kg [57.3 lb.]
(Add 1 kg [2.2 lb.] when the Endorser is installed.)
Dimensions (W x D x H): 470 x 677 x 278 mm [18.5" x 26.7" x 10.9"]
1.1.2 ENDORSER
Number of printable characters: 19 characters (max)
Character set: 43 characters
0123456789#./-:,’AB ····Z
Character size: 1.6 (W) x 2.8 (H) mm
Character pitch:
Printable lines: 1 line (main scan direction)
Inking: Ink roll type
2.4 mm ± 20%
Ink refill: Ink roll exchange
Ink color: Purple
Print position:
a: 7 ± 4 mm
b: 0 ± 5 mm
Document Feed Direction
Document
front side
a
1-2
b
G411V506.WMF
22 December 1998 COMPONENT LAYOUT
1.2 COMPONENT LAYOUT
1.2.1 FRONT VIEW
1
2
6
Overall
Information
3
5
4
No. Name Function
Platen cover
1
ADF exposure cover
2
Scale Used for positioning a document when placing it on the
3
Scanner indicator lamps T he green and red lights indicate the condition of the
4
5 Power switch Turns the power on and off.
Main exposure glass A document to be scanned in book mode is placed face
6
Covers the document and serves as a neutral
background for documents placed on the main
exposure glass.
Covers the scanner and closes the ADF exposure
cover interlock switch. Also contains an exposure glass.
exposure glass.
scanner.
down on this glass.
G411V500.WMF
1-3
COMPONENT LAYOUT 22 December 1998
1.2.2 RE AR VIEW
13
101112 789
G411V501.WMF
No. Name Function
7 Reset switch If this is pressed, the machine is reset.
DIP switches
8
Interface for reverse side
9
scanning
(Duplex model only)
10 SCSI connectors For connecting the SCSI cables.
SCSI ID rotary switch
11
12 Power plug inlet For connecting the power cord.
ADF cover Open this cover to clear paper jammed at the input
13
Used to select various scanning modes and test
modes.
Interface for the video signal during reverse side
scanning.
Used to select the SCSI ID and to select diagnostic
tests. Note that positions 8 and 9 are interpreted as
SCSI ID 7.
side.
1-4
22 December 1998 COMPONENT LAYOUT
1.2.3 ADF
20
19
18
14
15
G411V502.WMF
Overall
Information
16
17
No. Name Function
ADF Autom atically f eeds multi-page documents into the
14
Document table
15
Document guides Used to properly align the documents placed in the
16
17 Exit table Receives documents fed by the ADF after scanning.
Exit table extension This holds the documents output from the ADF; it can
18
Endorser cover
19
Document support wire If long documents are placed in the input tray, this helps
20
scanner.
Documents to be scanned using the ADF are placed
here.
input tray.
be extended to support long documents.
Open this cover to clean the endorser or replace the
ink.
to feed them correctly.
1-5
DRIVE LAYOUT 22 December 1998
1.3 DRIVE LAYOUT
1.3.1 SCANNER
2
3
1
7
4
7
7
4
6
5
7
No. Name Function
First scanner Moves the exposure lamp along the document and
1
Second scanner
2
3 Scanner drive wires Transmit motor power to the 1st and 2nd scanners.
4 Wire springs Tighten the scanner drive wires.
5 Motor belt Transmits motor power to the scanner drive wires.
6 Scanner motor Drives the scanners.
7 Pulleys Hold the scanner drive wires.
sends the light reflected from the document to the 2nd
scanner by means of a mirror.
Moves to keep the distance between the exposure lamp
and the CCD constant, and sends light reflected from
the 1st scanner to the CCD.
G411V503.WMF
1-6
22 December 1998 DRIVE LAYOUT
1.3.2 ADF
13
14
8
9
Overall
Information
10
11
12
G411V507.WMF
No. Name Function
8 Feed roller Feeds the top page of the original into the ADF.
Pick-up roller
9
Separation roller Stops the lower pages of the original while allowing the
10
White roller
11
(Duplex model only)
12 Feed-out rollers Feed the scanned original onto the exit table.
13 Paper transport drum Transports the original to the scanning position.
14 Paper transport rollers Hold the original against the paper transport drum.
Picks up and transports the top page of the original on
the document table.
top one to pass.
Allows the machine to correct for variations in the white
level of the CIS.
1-7
ELECTRICAL COMPONENT LAYOUT 22 December 1998
1.4 ELECTRICAL COMPONENT LAYOUT
1.4.1 SCANNER
11
10
9
8
1
2
7
3
4
6
5
No. Name Function
Home position sensor
1
2 SCU Controls the overall scanner function.
3 Lamp Stabilizer Provides ac power to the exposure lamp.
SBU Cont ains t he CCD, and outputs a video signal to the
4
5 Scanner Motor Drives the scanners.
6 SOP This contains the scanner indicator lamps.
7 PSU Provides dc voltages to the system.
8 IOB Controls the mechanical parts of the scanner.
IPU Board (Option) Performs automatic text/image separation, dynamic
9
RCU
10
(Duplex Model only)
11 Exposure lamp Illuminates the original for exposure.
Detects whether the first scanner is at the home
position.
SCU.
threshold, section area, and document size detection.
Outputs a video signal of the reverse side of the original
to the SCU.
G411V504.WMF
1-8
22 December 1998 ELECTRICAL COMPONENT LAYOUT
1.4.2 ADF
23
24
22
25
21
20
26
12
13
19
Overall
Information
14
15
16
17
18
G411V505.WMF
No. Name Function
ADF interlock switch
12
13 Paper transport motor Drives the paper transport drum.
Feed sensor
14
15 Read sensor Synchronizes the original exposure timing.
16 Paper feed motor This drives the pick-up and feed rollers.
CIS (Duplex model only) Contains t he CCDs and LEDs that scan the reverse
17
18 EDU (Option) Controls the mechanical parts of the endorser.
Endorser solenoid
19
(Option)
20 Relay sensor Checks for original misfeeds.
21 Feed-out sensor Detects when a document is at the feed-out position.
Document sensor Detects when a document is placed on the document
22
23 ADU Controls the mechanical parts of the ADF.
Document table position
24
sensor
25 Pick-up clutch Controls pick-up roller rotation.
Document table lift
26
clutch
Detects whether the ADF cover and platen cover are
open or closed; cuts the power supply to the machine.
Detects when a document is just before the feeding
position.
side of the original.
Moves the paper holding plate to hold the original at the
endorser’s printing position.
table.
Detects if the document table is at the feed position or
not.
Switches on to lift the document table up or down.
1-9
22 December 1998 INITIALIZATION
2. DETAILED SECTION DESCRIPTIONS
2.1 INITIALIZATION
Power on
1
Is the memory OK?
Yes
No
User Level: System error
User Level: System error
Service Level: Memory error
Service Level: Memory error
Detailed
Descriptions
2
3
4
5
6
7
8
Initialize the I/O port, E2PROM,
IPU, and memory controller
Initialize the scanner motor
Is the
home position check
OK?
Yes
Adjust the black level
Turn on the lamp
Scan the white plate
Is the
white level within specified
value?
Yes
Were there any
shading, or lamp, errors?
No
No
No
Yes
Home position error
Lamp error
No
Has the
initialization procedure been
tried three times?
14
Use the default value of the white
Yes
and black levels
10
11
12
9
Endorser motor turns on for 0.1s
one of the feed, read, or feed-
Are the
ADF or the document feeder
cover closed?
Yes
Is any
out sensors on?
No
Is there
any paper on the document
table?
Yes Yes
Detects document
No
Yes
No No
ADF open error
Paper jam
Is the document
table working properly?
READY
2-1
13
Document table error
G411D503.WMF
INITIALIZATION 22 December 1998
During power-up initialization, the scanner performs the following steps (refer to the
flow chart on the previous page).
1. Tests the ROM checksum and makes a RAM read/write test. If the CPU cannot
test these, the CPU determines that a memory error has occurred.
2. Initializes the I/O port, E2PROM, and gate arrays (IPU and memory controller).
3. Initializes the scanner motor driver.
4. Checks the home position sensor signal timing while moving the scanners. If
the CPU does not detect a signal change within the specified period, it
determines that a home position error has occurred.
5. Adjusts the difference between the even and odd black levels and total black
level.
6. Turns the exposure lamp on.
7. Adjusts the white level, and checks the peak level of the auto gain control. If the
CPU cannot adjust them to the specified levels, the CPU determines that a
lamp error has occurred.
8. If the black level or the white level cannot be adjusted properly during the
above initialization process, the scanner retries the initialization up to three
times. If the CPU detects an abnormal condition at the third time (step 14), the
CPU stores the default values of the black and white levels into the NVRAM on
the SCU.
9. Checks the ADF interlock switch signal. If the CPU detects that the switch is
open, it determines that an ADF open error has occurred.
10. When the endorser unit has been installed, the endorser moto r turns on for 0.1
second.
11. Checks the signals from the feed, read, and feed-out sensors. If any of them
are on, the CPU determines that there is a paper jam.
12. Checks the document sensor signal. If the CPU detects a document on the
document table, check #13 is not made until the document is removed.
13. Checks the document table position sensor signal timing while lifting and
lowering the document table.
14. See step 8.
2-2
22 December 1998 SCANNER MECHANISMS
2.2 SCANNER MECHANISMS
2.2.1 BOOK MODE
Overview
[B][C][A][E]
Detailed
Descriptions
[F] [D]
G411D521.WMF
The exposure lamp (a xenon lamp in this model) [A] illuminates the original. The
image is reflected onto a CCD (charge coupled device) [B] via the 1st, 2nd, and 3rd
mirrors, and through the lens [C].
The 1st scanner [D] consists of the exposure lamp, a reflector [E], and the 1st
mirror [F].
The exposure lamp is energized by an ac supply to avoid uneven light intensity
while the 1st scanner moves in the sub scan direction (down the page). The entire
exposure lamp surface is frosted to ensure even exposure in the main scan
direction (across the page).
The light reflected by the reflector is of almost equal intensity in all directions, to
reduce shadows on pasted originals.
2-3
SCANNER MECHANISMS 22 December 1998
Scanner Drive
[G]
[B]
[C]
[F]
[G]
[A]
[D]
[E]
G411D522.WMF
The scanner drive motor [A] (a stepper motor) drives the 1st and 2nd scanners [B,
C] through the timing belt [D], scanner drive pulley [E], scanner drive shaft [F], and
two scanner wires [G].
The IOB board drives the scanner drive motor. The scanning speed depends on
the scanning resolution. The returning speed depends on the distance from the
home position sensor.
2-4
22 December 1998 SCANNER MECHANISMS
Basic Scanning Procedure
When the scan command is received from the host computer, the scanner starts
scanning as explained in the following steps.
Initialization
[E]
[A]
[D]
[F]
[G]
[B]
Detailed
Descriptions
[C]
G411D524.WMF
The scanner checks the home position, scanner cover, and memory. If an error is
detected, the scanner motor will stop.
The scanner scans the white plate [A] on the underside of the ADF exposure cover
to perform the shading funct i on.
Image Scanning
The scanner starts to scan the image area at the designated position [B]. The
scanner stops after scanning the designated image area [C]. The arrows indicate
that the scan start position and image area depend on the settings input by the
user.
Scanner Reversing
After the image has been scanned, the scanners return to the home position [D].
The scanners are stopped when the first scanner activates the home position
sensor [E]. If the scanner home position sensor is not activated within a certain
time, a home position sensor erro r will occu r.
2-5
SCANNER MECHANISMS 22 December 1998
Optional Steps (Optional IPU Board)
Size Detection
If selected, this is done after the ‘Initialization’ step.
1) Main Scan Direction (Document Width)
The first scanner moves to the book mode standard position ([F] on the previous
page). Then, the scanner scans 5 mm from the book mode standard position.
The scanner determines the document width in the main scan direction from the
output signal level. The edge of the document is detected by the difference
between the level of the document data and the background signal which is
provided by the silver plate [G] attached to the platen cover across the main scan.
If there is a gap at the leading edge, such as a tear (or a black stripe), extending
more than 1 mm across the paper and more than 5 mm down the paper, the
machine cannot detect the document width past this gap. In this case, an error
message may appear, and scanning is impossible. . Disable this feature to allow
the machine to scan this document.
2) Sub Scan Direction (Document Length)
The scanner detects the document size only in the main scan direction, and the
scanner driver determines that the document length is the same as for a standard
paper size of the same width.
NOTE:
The scanner always assumes the paper is in a lengthwise orientation (i.e.,
the main scan is the short side). Also, in USA models, if Letter width is
detected, the paper is always assumed to be Letter size (this means that
the last few inches of a Legal-size original will not be scanned).
Read Size Command
If selected, this is done after the ‘Initialization’ step.
1) Read Size Command
If the scanner receives the Read Size command in book mode, it detects the size
in the main scan direction as described above.
The scanner sends the width data to the host computer.
After detecting the document size, the scanner scans the detected area.
Abort Command
This can occur at any time during the basic scanning procedure.
If the Abort command is received during scanning, the scanner motor is stopped.
Then the scanner returns to the home position ([D] in the previous diagram).
If this command is received while the scanner is reversing or checking the home
position, the operation is not interrupted.
2-6
22 December 1998 SCANNER MECHANISMS
2.2.2 ADF MODE
Overview
[D]
[F]
[G]
[H]
[A]
[N]
[B]
[C]
[M]
[E]
[L]
Detailed
Descriptions
[J]
[K]
G411D517.WMF
[I]
When the originals are pl aced on the do cument table [ A], the document sensor [B]
detects them. The pick-up roller [C] picks up the originals and transports them to
the feed roller [D]. The separation roller [E] turns in the opposite direction to the
feed roller. As a result, just one original is sent to the paper transport drum [G]. The
feed sensor [F] detects whether the original has reached the transport drum or not.
Then the original turns with the transport drum through the read sensor [H]. While
the original passes over the ADF scanning position [J], the scanner [K] reads the
original. After reading, the original goes to the exit table [N]. The feed-out sensor
[M] detects whether the original is fed out or not. The relay sensor [L] detects when
an original is jammed in the area between the read sensor and the feed-out
sensor. This sensor is monitored at all times except when the ADF is feeding a
document.
2-7
SCANNER MECHANISMS 22 December 1998
Basic Scanning Procedure
When the scanner receives t he ADF scanning command, the scanner scans the
original as described below.
1) ADF Mode
The scanner performs the home position check and the shading process. If a home
position error is detected, the scanner [K] will stop imme diately. If an ADF cover
open error or memory error is de tec ted, the scanner will stop after returning to the
home position.
The first carriage moves to the ADF scanning position [J] from the scanner home
position [I]. Then the paper transport motor starts.
2) SADF Mode
The scanner waits until the designated time for the originals to be placed on the
document table [A].
When the originals have b een placed on the document table, the sa me procedure
as for ADF mode is carried out.
2-8
22 December 1998 SCANNER MECHANISMS
Document Table Lift
[C]
[G]
[F]
Detailed
Descriptions
[A]
[B]
[E]
[H]
[D]
[F]
[A]
G411D518.PCX
The lift mechanism consists of the document table lift clutch [A], the lift shaft [B],
the document table position sensor [C], and the sensor actuator on the gear [D].
In standby mode, the bend in the lift shaft [H] is pointing downwards and the
actuator is just inside the sensor.
When an original is placed on the document table, the document sensor [E] is
activated. Then the paper feed motor [G] turns on. At the same time, the document
table lift clutch [A] turns on to rotate the lift shaft.
At this time, the actuator starts to turn anticlockwise, and the flat part of the spring
[I] that is loosely attached to the bend in the lift shaft pushes up the document table
(see the next page for a diagram).
When the top of the document stack is pushed up against the pi ck-up roller, it can
rise no more. However, the mechanism continues to push up against the tray until
a half-turn of the shaft has been completed (i.e., until the actuator leaves the
document table position sensor). At that time, the document table lift clutch and the
paper feed motor turn off. If the actuator does not leave the sensor within a certain
time, a document table error will occur.
The feed motor turns on again at a motor speed which depends on the scanning
resolution, and the pick-up clutch [F] turns on to feed the top sheet of the original
(see Original Feed and Separation).
2-9
SCANNER MECHANISMS 22 December 1998
[I]
[H]
G411D519.WMF
When the first original is being fed, the bend in the lift shaft is pointing up, and the
spring is at maximum compression. As sheets of the document are scanned, the
spring pushes the document table upwards so that the top of the stack is always
against the pick-up roller.
When all page s of the original have been fed out of the ADF, the document table
lift clutch and paper feed motor are energized to lower the tray. They turn off when
the document table sensor is deactivated. If the sensor is not deactivated within the
designated time, a document table error will occur.
2-10
22 December 1998 SCANNER MECHANISMS
Original Feed and Separation
[D]
[E]
[F]
[A]
[C]
Detailed
Descriptions
[B]
G411D520.WMF
To feed the original, the paper feed motor and the paper transport motor (which
drives the paper transport drum) turn on. The paper feed motor drives the pick-up
roller [A] through a train of gears and the pick-up clutch [B]. The pick-up clutch
turns on to feed the top sheet of the original. If the pick-up roller feeds multiple
pages of the original, the separation roller [C] and the feed roller [D] separate these
pages (the separation mechanism is friction-based).
When the leading edge of the original ac tivates the feed sensor [E], the paper feed
motor and the pick-up clutch turn off, then the paper transport drum [F] feeds the
original to the scanning position.
Image Scanning
The scanner starts to scan the image when the leading edge has passed the read
sensor by a certain distance (measured by motor pulses).
When the CP U has fed the trailing edge of the original 30 mm past the f eed-out
sensor, the transport motor turns off.
2-11
SCANNER MECHANISMS 22 December 1998
Optional Steps
Size Detection
[A]
[B]
[D]
G411D523.WMF
[C]
If selected, this is done after document table lift/paper feed.
1) Main Scan Direction (Document Width)
This function will be available when the optional IPU board is installed.
First of all, the original is fed to the scan ready position between the read sensor
[B] and the size detection position [C]. Then the first scanner moves to the size
detection position [C] from the ADF scanning position [D]. After that, the original is
fed to the ADF scanning position.
As a result of the above operation, the original is fed 5 mm past the first scanner.
Then the CPU detects the original width. The edge of the document is detected by
the difference between the level of the document data and the background level,
which is provided by the black bracket located over the ADF exposure cover.
If there is a gap at the leading edge, such as a tear (or a black stripe), extending
more than 1 mm across the paper and more than 5 mm down the paper, the
machine cannot detect the document width past this gap. In this case, an error
message may appear, and scanning is impossible. Disable this feature to allow the
machine to scan this document.
After finishing the above operation, the first scanner returns to the ADF scanning
position.
2) Sub Scan Direction (Document Length)
The length of the original is calculated by counting the motor pulses while the feed
sensor [A] is on. (The length is detected during scanning.)
2-12
22 December 1998 SCANNER MECHANISMS
Read Size Command
If selected, this is done after document table lift/paper feed.
If the scanner receives a Read Size command in ADF mode, it detects the
document size in the main scan direction as described on the previous page.
The scanner sends the width data to the host computer.
Abort and Unload Commands
These can occur at any time during the basic scanning procedure.
When the CP U receives the Abort or the Unload command during paper transport,
the scanner feeds out any original that is in the ADF.
Detailed
Descriptions
2-13
PAPER MISFEED DETECTION 22 December 1998
2.3 PAPER MISFEED DETECTION
Start
MAX
READ
Paper Feed Motor
Pick-up Clutch
OFF
Document Table
Lift Clutch
Document Table
Position Sensor
Document Sensor
MAX
Paper Transport
Motor
Feed Sensor
Read Sensor
Feed-out Sensor
FGATE
FGATE: When this signal is high, scanned data is valid
READ
OFF
t1
t2
t1 t2 t3 t4 t5 t6
200 dpi
400 dpi
Within
3,000
Within
3,000
210 205 44 24.64
210 205 88 172.04
Original End
J1
J4
t3
J2
J5
J3
J6
t5 t6
G411D527.WMF
Unit: milliseconds
L x 0.011
x 200
L x 0.011
x 400
2-14
L: Document length (mm)
22 December 1998 PAPER MISFEED DETECTION
J1: The leading edge of the original does not reach the feed sensor within the time
required for feeding the distance between the pick-up roller and the feed sensor
+ 150 mm after the pick-up clutch turned on.
J2: The leading edge of the original does not reach the read sensor within the time
required for feeding the distance between the feed sensor and the read sensor
+ 150 mm after the feed sensor was activated.
J3: The leading edge of the original does not reach the feed-out sensor within the
time required for feeding the distance between the read sensor and the feed
out sensor + 30 mm after the read sensor was activated.
J4: The trailing edge of the original doe s not pass through the feed sensor within
the time required for feeding the maximum original length (2 m) + 60 mm after
the feed sensor was activated.
J5: The trailing edge of the original doe s not pass through the read sensor within
the time required for feeding the original + 75 mm after the read was activated.
J6: The trailing edge of the origin al does not pass through the feed-out sensor
within the time required for feeding the original length + 75 mm after the feedout sensor was activated.
If an original jam or an original non-feed is detected, the paper transport motor,
paper feed motor, and the exposure lamp turn off. Then, the appropriate LEDs
inform the user of the machine’s status.
Detailed
Descriptions
If an original remains in the ADF, the original is fed out and the paper transport
motor stops.
2-15
IMAGE PROCESSING 22 December 1998
2.4 IMAGE PROCESSING
2.4.1 OVERVIEW
(Duplex model only)
CCD
SBU
CCD
IOB
CIS
SCU
DRAM
Memory
Control
IC
SCSI
Control
IC
IPU
IPU
Memory
Control
IC
RCU
DRAM
G411D508.WMF
The CCD generates two analog video signals. The SBU (Sensor Board Unit)
converts these analog signals to 8-bit digital signals, then it sends these digital
signals to the SCU (Scanner Control Unit) board through the IOB board. The IPU
(Image Processing Unit) IC on the SCU does the image processing, then the image
data goes to the computer through the Memory Control IC and the SCSI controller.
The CIS (Contact Image Sensor) unit in the duplex model for reverse-side
scanning outputs two digital signals. The IPU on the RCU (Reverse Control Unit)
board does the image processing, then the image data goes to the computer
through the SCU.
2-16
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