Canon DADF-B1 User manual

COPYRIGHT © 1999 CANON INC. CANON DADF-B1 REV.0 APR. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
FY8-13G6-000
REVISION 0
APR. 1999
DADF-B1

COPYRIGHT © 1999 CANON INC. CANON DADF-B1 REV.0 APR. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
IMPORTANT
THIS DOCUMENT IS PUBLISHED BY CANON INC., JAPAN, TO SERVE AS A SOURCE OF
REFERENCEFORWORKINTHEFIELD.
SPECIFICATIONS AND OTHER INFORMATION CONTAINED HEREIN MAY VARY SLIGHTLY
FROM ACTUAL MACHINE VALUES OR THOSE FOUND IN ADVERTISING AND OTHER
PRINTED MATTER.
ANYQUESTIONSREGARDING INFORMATION CONTAINEDHEREIN SHOULD BEDIRECTED
TOTHE COPIER SERVICE DEPARTMENT OFTHE SALES COMPANY.
THISDOCUMENTISINTENDEDFOR ALL SALESAREAS,ANDMAYCONTAININFORMATION
NOT APPLICABLETO CERTAIN AREAS.
COPYRIGHT © 1999 CANON INC.
Printed in Japan
Imprimé au Japon
Use of this manual should be strictly su-
pervised to avoid disclosure of confidential
information.
Preparedby
OFFICEIMAGINGPRODUCTSTECHNICALSUPPORTDIVISION
CANONINC.
5-1,Hakusan7-chome,Toride,Ibaraki, 302-8501Japan

COPYRIGHT © 1999 CANON INC. CANON DADF-B1 REV.0 APR. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
i
INTRODUCTION
This Service Manual provides information needed to service the ADF in the field. This Service
Manual consists of the following chapters:
Chapter 1 “General Description” introduces the ADF’s features and specifications, and shows
how to operate it.
Chapter 2 “BasicOperation”introducesthe ADAF’smechanicalandelectrical systems;italso
explains the principles used in these systems and the timing at which they are
operated with reference to the ADAF’s electrical circuitry.
Chapter 3 “Mechanical System” explains the ADAF’s mechanical construction and how its
parts may be disassembled/assembled and adjusted.
Chapter 4 “Maintenance and Servicing” provides tables of periodically replaced parts and
consumables/durables and scheduled servicing charts.
Chapter 5 “Troubleshooting” provides tables of maintenance/inspection, standards/
adjustments,and problem identification(imagefault/malfunction).
Appendix contains a general timing chart and general circuit diagrams.
The descriptions in this Service Manual are subject to change without notice for product
improvement or other purposes, and major changes will be communicated in the form of Service
Informationbulletins.
All service persons are expected to have a good understanding of the contents of this Service
Manual and all relevant Service Information bulletins, and be able to identify and isolate faults in the
machine.

COPYRIGHT © 1999 CANON INC. CANON DADF-B1 REV.0 APR. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
iii
CONTENTS
CHAPTER 1 GENERAL DESCRIPTION
CHAPTER 2 BASIC OPERATION
I. FEATURES ................................1-1
II. SPECIFICATIONS......................1-2
III. NAMES OF PARTS ....................1-4
A. External View.........................1-4
B. Cross Section ........................1-4
IV. OPERATIONS ............................1-5
A. Original Set Indicator .............1-5
B. Making Copies.......................1-5
C. Warnings and Actions............1-5
D. Routine Maintenance by the
User.......................................1-6
CHAPTER 3 MECHANICAL SYSTEM
I. BASIC CONSTRUCTION...........2-1
A. Outline of Electrical Circuitry....2-1
B. Inputs to the ADF Controller
PCB.......................................2-2
C. Outputs from the ADF Controller
PCB.......................................2-4
II. BASIC OPERATIONS ................2-5
A. Outline ...................................2-5
B. Detecting an Original.............2-6
C. Picking Up and Separating
Originals ..............................2-11
D. Moving Originals..................2-18
E. Turning Over an Original/
Delivery ...............................2-23
F. Movement of Originals.........2-32
G. Detecting an Original Jam ...2-43
H. Alarm Detection ...................2-47
I. Power Supply ......................2-50
I. BASIC CONSTRUCTION...............3-1
A. External Covers .....................3-1
B. Removing the Feed Belt Unit ..3-4
C. ADF Controller PCB ..............3-5
II. DRIVE SYSTEM............................3-6
A. Removing the Pickup Unit .....3-6
B. Removing the Separation
Motor(M1) .............................3-6
C.
RemovingtheFeedMotor(M2) ....3-7
D. Reversal Delivery Unit...........3-8
E. Removing the Reversal Delivery
Motor(M3) .............................3-9
III. FEEDING SYSTEM..................3-10
A. Removing the Separation Pad
Assembly.............................3-10
B. Removing the Separation
Roller ...................................3-11
C. Removing the Pickup Roller..3-12
D.
MountingtheSeparationRoller
Unit ........................................
3-13
E. Removing the Reversing Roller
and Feed Roller...................3-14
F. Replacing the Feed Belt ......3-16
VI. SENSORS .................................3-18
A. Removing the Original Set Sen-
sor PCB (U503) ...................3-18
B. Removing the Original Set Indi-
cator LED PCB ....................3-18
C. Removing the Last Original
Sensor PCB (U504).............3-19
D. Original Width Detecting Volume
(VR) .....................................3-19
E. Removing the Pre-Registration
Sensor (U502) .....................3-21
F. Removing the Reversal Outlet
Sensor (U505) .....................3-21

iv
COPYRIGHT © 1999 CANON INC. CANON DADF-B1 REV.0 APR. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
CHAPTER 4 MAINTENANCEANDSERVICING
I. PERIODICALLY REPLACED
PARTS .......................................4-1
II.
CONSUMABLESAND
DURABLES ..................................
4-1
III. SCHEDULED SERVICING
CHART.......................................4-2
CHAPTER 5 TROUBLESHOOTING
APPENDIX
I. STANDARDS AND ADJUST-
MENTS.......................................5-1
A. Mechanical System ...............5-1
B. Electrical System ...................5-4
II. TROUBLESHOOTING................5-9
A. Troubleshooting
Malfunctions ........................5-10
III. ARRANGEMENT OF THE ELEC-
TRICAL PARTS .......................5-12
A. Motors, Solenoids, and
Sensors ...............................5-12
B. PCBs ...................................5-14
IV. VARIABLE RESISTORS (VR),
LIGHT-EMITTING DIODES, AND
CHECK PINS BY PCB.............5-15
A. ADF Controller PCB ............5-15
B. Sensor PCBs.......................5-16
C. Indicator PCB ......................5-18
V. SERVICE MODE AND DIP
SWITCH ...................................5-19
A. Outline .................................5-19
B. Service Mode.......................5-20
C. Using the DIP Switch...........5-28
VI. SELF DIAGNOSIS....................5-32
A. ADF Self Diagnosis .............5-32
A. GENERAL TIMING CHART ......... A-1
B. SIGNALS AND
ABBREVIATIONS...................... A-5
C. GENERAL CIRCUIT
DIAGRAM.................................. A-7
D. ADF CONTROLLER PCB......... A-8
E. PRE-REGISTRATION SENSOR
PCB ......................................... A-12
F. REVERSAL OUTLET SENSOR
PCB ......................................... A-13
G. ORIGINAL SET INDICATOR LED
PCB ......................................... A-15
H. ORIGINAL SET SENSOR ....... A-17
I. LAST ORIGINAL SENSOR ..... A-18
J. SPECIAL TOOLS..................... A-19
K. SOLVENTS AND OILS............ A-20

COPYRIGHT © 1999 CANON INC. CANON DADF-B1 REV.0 APR. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
CHAPTER 1
GENERAL DESCRIPTION
I. FEATURES ................................1-1
II. SPECIFICATIONS......................1-2
III. NAMES OF PARTS ....................1-4
A. External View.........................1-4
B. Cross Section ........................1-4
IV. OPERATIONS ............................1-5
A. Original Set Indicator .............1-5
B. Making Copies.......................1-5
C. Warnings and Actions............1-5
D. Routine Maintenance by the
User.......................................1-6

COPYRIGHT © 1999 CANON INC. CANON DADF-B1 REV.0 APR. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
1-1
CHAPTER 1 GENERAL DESCRIPITON
I. FEATURES
1. Small in size, and light in weight.
It is a document feeder designed as a single-frame unit for small size and light weight.
2. Handles double-sided originals.
It isequippedwith areversingdelivery unit,capable ofturningover originalsand returningthem
to the copyboard glass.
3. Wingless design.
Its delivery tray is of an integrated construction.
4. Automatic identification of original size.
It is capable of identifying the size of an original in terms of lengthwise (feeding) and
breadthwise directions for communication to its host copier.
4. Handles mixed sizes.
It can accommodate originals of different sizes (of the same width, i.e., configuration).
5. Accommodates thick originals.
It is equipped with a book equalizing hinge, enabling the use of a thick original (50 mm thick;
e.g., book).
6. Reversal delivery flapper.
It rotates the reversal delivery motor clockwise and counterclockwise to open and close the
flapper, switching the feeding path.

CHAPTER 1 GENERAL DESCRIPITON
1-2
COPYRIGHT © 1999 CANON INC. CANON DADF-B1 REV.0 APR. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
II. SPECIFICATIONS
Item Specifications
Pickup method Automatic pickup/delivery
Type of original Original tray: double-sided sheet (52 to 105 g/m2); see Note 1.
Copyboard glass: book (50 mm thick max.)
Size of original A3 (279 mm x 431.8 mm; 11"x17") to A5 (STMT)
Length: 140 to 432 mm (feeding direction)
Width: 140 to 297 (305) mm
Note: The values in parentheses indicate when the guide lock is released.
Orientation of original Face up
1st page at top
Placement of original Center reference
Original separation Separation pad (top separation)
Original processing
mode Single-sided original processing (small-size, large-size), double-sided original
processing
Height of stack
(80 g/m
2
paper) 30 sheets (small size; A4, B5, A5, STMT, LTR) 15 sheets (large-size;A3, 279x431.8 mm/11"x17", B4, LGL)
Mixing sizes Possible (of the same width)
Size identification Yes (feeding direction + default width)
Residual original
detection Yes (by LED)
2-on-1 function No (by copier's memory)
Stamp No
Last original detection 690 msec or less
Communication with
copier IPC 2
Power supply 24 VDC (from copier)
Serial numbers ZSB xxxxx AB
ZSC xxxxx INCH/A
ZSD xxxxx A
ZSE xxxxx AB/INCH
Maximum power
supply 160 W or less at peak; 39 W in average
Operating environment
temperature/humidity
range
Same as copier
Dimensions 583 (W) x 506 (D) x 179 (H) mm
Weight 12.8 kg (approx.)
Table 1-201

COPYRIGHT © 1999 CANON INC. CANON DADF-B1 REV.0 APR. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
1-3
CHAPTER 1 GENERAL DESCRIPITON
Note 1:
The following may not be used as an
original:
• Sheet with holes (as for filing).
• Sheet with a staple, clip, or adhesive.
• Sheet with a cut-and-paste patch.
• Sheet with a carbon back.
• Sheet with large curling, bending, or
wrinkling.
Ifan original haslarge curling, straighten
it out as much as possible, and place it so that
the curling edge is the trailing edge.
Note 2:
Time Taken to Replace Originals
The value indicates the time passing from
when an original is moved to when its trailing
edge reaches the point of exposure. However,
it does not include separation of the original.
Note:
The specifications are subject to change
for product improvement.
Figure 1-201
Time to replace originals Point of exposure
(leading edge of image)

CHAPTER 1 GENERAL DESCRIPITON
1-4
COPYRIGHT © 1999 CANON INC. CANON DADF-B1 REV.0 APR. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
III. NAMES OF PARTS
A. External view
Pickup Assembly
[1] Pickup roller
[2] Lifter
[3] Separation pad
[4] Separationroller
[5] Registrationroller
Figure 1-301
B. Cross Section
[1] Original tray
[2] Auxiliary tray
[3] Slide guides
[4] Original Set indicator
[5] Last original sensor
[6] Pickup unit cover
[7] Reversal delivery unit cover
[8] Original delivery tray
Feeding Assembly
[6] Feeding belt
[7] Feeding belt drive roller
[8] Retaining roll
[9] Feeding belt linkage roller
Reversal Delivery Assembly
[10] Reversal delivery flapper
[11] Reversaldelivery
registrationroller
[12] Reversing roller
Figure 1-302
[1][3]
[4]
[7]
[8]
[6][5]
[2]
[4][1]
[7] [8] [9]
[10]
[11]
[6]
[12]
[2]
[3]
[5]
Pickup assembly
Feeding assembly
Reversal
delivery
assembly

COPYRIGHT © 1999 CANON INC. CANON DADF-B1 REV.0 APR. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
1-5
CHAPTER 1 GENERAL DESCRIPITON
IV. OPERATIONS
A. Original Set Indicator
The Original Set indicator turns on when an original is on the original tray, and it starts to flash
when a jam occurs.
B. Making Copies
1) Adjust the slide guides to suit the size of the originals.
2) Place the stack of originals against the end plate of the original tray with the first page on top.
3) Set the copier to the appropriate copying mode.
4) Press the copier’s Copy Start key.
C. Warnings and Actions
You can suspect an original jam if the Original Set indicator has started to flash. Make the
following checks, and take the appropriate actions:
1) Open the pickup unit cover and the reversal delivery unit; then, remove any original jam.
2) Remove the originals from the original tray.
3) Open the ADF, and remove any original jam.
4) Remove any original from the copyboard glass.
5) Close the ADF.
6) Put the originals back into order, and place the stack on the original tray once again.
7) Press the copier’s Copy Start key.
Figure 1-401

CHAPTER 1 GENERAL DESCRIPITON
1-6
COPYRIGHT © 1999 CANON INC. CANON DADF-B1 REV.0 APR. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
D. Routine Inspection by the
User
Instruct the user to clean the following on a regular basis:
1. Copyboard Glass
Clean it using a cloth moistened with water or alcohol; then, dry wipe it.
2. Feeding Belt
Clean it using water or alcohol.
3. Others
If any part of the external panels of the ADF is soiled, clean it with a solution of mild detergent;
then, dry wip it.

COPYRIGHT © 1999 CANON INC. CANON DADF-B1 REV.0 APR. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
CHAPTER 2
BASIC OPERATION
I. BASIC CONSTRUCTION...........2-1
A. Outline of Electrical Circuitry....2-1
B. Inputs to the ADF Controller
PCB.......................................2-2
C. Outputs from the ADF Controller
PCB.......................................2-4
II. BASIC OPERATIONS ................2-5
A. Outline ...................................2-5
B. Detecting an Original.............2-6
C. Picking Up and Separating
Originals ..............................2-11
D. Moving Originals..................2-18
E. Turning Over an Original/
Delivery ...............................2-23
F. Movement of Originals.........2-32
G. Detecting an Original Jam ...2-43
H. Alarm Detection ...................2-47
I. Power Supply ......................2-50

COPYRIGHT © 1999 CANON INC. CANON DADF-B1 REV.0 APR. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
2-1
CHAPTER 2 BASIC OPERATION
Figure 2-101
I. BASIC CONSTRUCTION
A. Outline of Electrical Circuitry
The major electrical mechanisms of the ADF are controlled by a microprocessor (CPU) on the
ADF controller PCB.
The microprocessor is designed to read signals from sensors and its host copier to generate
signals used to drive loads (motors, brakes).
CPU
(Q1)
ROM
(Q2)
IPC
24V 5V
5 VDC
power supply
(Q3)
EEPROM
(Q4)
Power supply
circuit
ADF controller PCB
Copier
Sensor Motor
Brake
Indicator
LED PCB
Variable
resistor

CHAPTER 2 BASIC OPERATION
2-2
COPYRIGHT © 1999 CANON INC. CANON DADF-B1 REV.0 APR. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
B. Inputs to the ADF Controller PCB
1. Inputs to the ADF Controller PCB (1/2)
J1101J101
SR1
3
2
1
3
2
1
J6A-3 +5V
J6FA-2 FMCK
J6FA-1
1
2
3
1
3
2
3
2
1
3
1
2
3
1
2
J102
SR2
11
9
10
J6A-4 +5V
J6FA-6 SCVR
J6FA-5
4
6
5
9
8
10
11
7
3
1
2
3
4
2
1
5
3
1
2
3
4
5
2
1
J103
SR3
U503
8
6
7
3
4
2
1
5
J6A-7
J6A-11
J6FA-12
J6FA-13
J6FA-14
J6FA-10
+5V
+5V
+5V
+24V
J6FA-9 SPR
EMP
EPLED
J6FA-8
1
2
3
8
7
6
3
2
1
1
2
3
J6B-8 +5V
J6FA-9 WIDE
J6FA-10
3
4
5
4
1
3
2
1
5
4
J301
J201
J1102
U502
U508
J6B-6
J6FB-5
J6FB-3
J6FB-4
J6FB-7
+24V
ENT
ETLED
+5V
3
4
2
1
5
6
5
7
8
4
3
4
2
1
5
3
4
5
2
1
J401 J1801
U504
J801
J6B-12
J6FB-13
J6FB-14
J6FB-15
J6FB-11
+24V
LAST
LTLED
ADF controller PCB
Feed motor clock sensor
Pickup unit cover sensor
Separation sensor
Original set sensor
Pre-registration sensor
Original width detecting
volume
Last original sensor
When an original blocks the
sensor, ’1’.
Generates an analog voltage to
suit the width of the original placed
on the original tray.
When the original blocks the
sensor, ’0’.
When an original blocks the
sensor, ’0’.
When an original is detected, ’0’.
(When the light-blocking plate is
not at the sensor.)
When the pickup unit cover is
opened, ’0’.
(When the light-blocking plate is
not at the sensor.)
While the feed motor is rotating,
alternates between ’1’ and ’0’.
Figure 2-102

COPYRIGHT © 1999 CANON INC. CANON DADF-B1 REV.0 APR. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
2-3
CHAPTER 2 BASIC OPERATION
Figure 2-103
2. Inputs to the ADF Controller PCB (2/2)
J1107
J107
SR4
3
1
2
6
4
5
J7A-1 +5V
J6FA-3 EENT
J6FA-2
1
3
2
4
6
5
3
1
2
3
1
2
3
1
2
J108
SR5
3
1
2
J7A-4 +5V
J6FA-6 EREG
J6FA-5
3
1
2
3
1
2
J109
SR6
J7B-1 +5V
J6FA-3 OPEN*
J6FA-2
1
2
3
1
2
3
J110
SR7
J7B-6 +5V
J6FA-5 EMCK
J6FA-4
3
1
2
3
1
2
J111
SR8
J7B-7 +5V
J6FA-9
The asterisk (*) indicates that the signal turns on
when ’0’ (low active).
When the reversal delivery unit cover
is opened, ’0’.
(When the light-blocking plate is at
the sensor.)
While the reversing delivery motor is
rotating, alternates between ’1’ and ’0’.
When the ADF is opened, ’0’.
(When the light-blocking plate is
not at the sensor.)
When an original blocks the sensor, ’0’.
When an original is detected, ’1’.
(When the light-blocking plate is at
the sensor.)
When an original is detected, ’1’.
(When the light-blocking plate is at
the sensor.)
J6FA-8
3
4
1
2
5
3
2
5
4
1
3
2
1
5
4
J103
U505
3
2
5
4
1
J7B-10
J6FA-9
J6FA-7
J6FA-8
J6FA-11
+5V
+24V
TURN
TULED
J501 J502
ADF controller PCB
Reversal delivery inlet
sensor
Reversal delivery
registration sensor/delivery sensor
Reversal outlet sensor
ADF open/closed sensor
Reversal delivery motor
clock sensor
Reversal delivery
unit cover sensor

CHAPTER 2 BASIC OPERATION
2-4
COPYRIGHT © 1999 CANON INC. CANON DADF-B1 REV.0 APR. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
Figure 2-104
C. Outputs from the ADF Controller PCB
1. Outputs from the ADF Controller PCB (1/1)
J104
M1
M
M
M
BK
1
2
J5-1
J6FA-2
1
2
J104
1
2
J5-3
J6FA-4
1
2
J112
1
2
J5-5
J6FAJ5-6
1
2
J112
1
2
J9-1
J6FA-2
1
2
M2
+24V
+5V
M3
BK1
U507
BK
J701
2
1J6B-1
J6FA-2
2
1
EJM2
OGLED
SPM1
SPM2
FDM1
FDM2
EJM1
ADF controller PCB
Separation motor
Feed motor
Feed motor brake
Reversal delivery motor
Original Set indicator (LED)
When ’0’, the Original Set indicator
turns on.
See "Controlling the Reversal
Delivery Motor (M3)" on p. 2-29.
When ’0’, the brake (BK1) turns on.
See "Controlling the
Feed Motor (M2)" on p. 2-21.
See "Controlling the
Separation Motor (M1)" on p.2-16.

COPYRIGHT © 1999 CANON INC. CANON DADF-B1 REV.0 APR. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
2-5
CHAPTER 2 BASIC OPERATION
II. BASIC OPERATIONS
A. Outline
The ADF is equipped with three motors for separation, feeding, and delivery (reversal)
and one brake.
The separation motor (M1)is usedto separateand pick uporiginals. Thefeed motor (M2)is used
to move originals to and stop them at the copyboard glass, while the reversal delivery motor (M3) is
deigned to deliver or reverse originals. The brake (BK) serves to stop the operation of the feed motor
(M2).
M2
BK
M3
M1
U503
U504
U505
U508
SR1
SR7
SR8
SR4
SR5
U507
SR3
SR6
SR2
Copier
ADF controller PCB
Last original detection signal (LAST) Original size detection signal (WIDE) Pickup registration signal (ENT) ADF open/closed detection signal (OPEN) Reversal/delivery outlet paper detection signal (TURN) Reversal delivery unit cover open/ closed detection signal (ECVR) Reversal/delivery motor clock signal (EMCK) Reversal delivery motor drive signal (EJM1, EJM2) Reversal/delivery registration signal/ delivery detection signal (EREG) Reversal/delivery inlet paper detection signal (EENT) Feed motor clock signal (FMCK) Original pickup tray paper detection signal (EMP) Original Set indicator ON signal (OGLED) Separation motor drive signal (SPM1, SPM2) Pickup detection signal (SPR) Pickup unit cover open/closed detection signal (SCVR) Feed motor brake drive signal (Bk*) Feed motor drive signal (FDM1, FDM2)
Figure 2-201

CHAPTER 2 BASIC OPERATION
2-6
COPYRIGHT © 1999 CANON INC. CANON DADF-B1 REV.0 APR. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
B. Detecting an Original
1. Outline
The ADF is equipped with the following
three types of original detecting mechanisms:
a. Detecting the Presence/Absence of
an Original
It detects the presence/absence of an
original on the original tray.
b. Identifying the Size of an Original
Itidentifies the length(feeding direction)
and width of an original.
c. Detecting the Last Original
It detects the trailing edge of the last
original.
a. Detecting the Presence/Absence of
an Original
The presence/absence of an original on the
original tray is detected by the original set
sensor. When an original is placed on the
originaltray, the lightfrom the light-emitting
side of the original set sensor is blocked, and
the light-receiving side of the original set
sensor starts to send the original detection
signal (EMP) to the ADF controller PCB.
In response, the ADF controller PCB
generates the original set indicator ON signal
(OGLED) to turn not the Original Set indicator
(U507).
U503
U507
Prism
Original Set sensor Original
Original set indicator ON signal (OGLED) Original tray paper detection signal (EMP)
ADF controller PCB
Original Set indictor
LED
Figure 2-202

COPYRIGHT © 1999 CANON INC. CANON DADF-B1 REV.0 APR. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
2-7
CHAPTER 2 BASIC OPERATION
b. Identifying the Size of an Original
The ADF identifies the size of an original
in terms of length (feeding direction) and
width.
The length is computed in reference to the
number of clock signals from the pre-
registration sensor (U502) and the registration
roller.
When the pre-registration sensor detects
the leading edge of an original (ON) and the
trailing edge (OFF), the ADF controller
computes the time taken by the original to
move past the pre-registration sensor with
reference to the number of clock signals from
the feed motor clock sensor (SR1) to find out
the size in the lengthwise direction (feeding
direction).
The ADF controller uses the result to
identify a default size, and communicates it to
the copier so that copy paper of the appropriate
size may be selected.
The ADF refers to the original width
detecting volume (U508) located inside the
originaltray to findout the width ofan original.
The original width detecting volume
operates in conjunction with the slide guides,
and the resistance of the voltage varies in
analog mode. The ADF controller uses
changes occurring in the resistance as the
original size detection signal (WIDE), and uses
themto find outthe width ofaspecific original.
SR4
U502
M2
BK
Prism
Registration roller
Feed motor clock
sensor
Feed motor
Original
Pre-registration
sensor
Original tray paper detection signal (ENT)
Feed motor clock signal (FMCK)
ADF controller PCB
Figure 2-203
Original width detecting volume
Figure 2-204