CHAPTER 2 BASIC OPERATION
b. Identifying the Size of an OriginalThe ADF refers to the original width
The ADF identifies the size of an originaldetecting volume (U508) located inside the
in terms of length (feeding direction) andoriginal tray to find out the width of an original.
width.The original width detecting volume
The length is computed in reference to theoperates in conjunction with the slide guides,
number of clock signals from the pre-and the resistance of the voltage varies in
registration sensor (U502) and the registrationanalog mode. The ADF controller uses
roller.changes occurring in the resistance as the
When the pre-registration sensor detectsoriginal size detection signal (WIDE), and uses
the leading edge of an original (ON) and thethem to find out the width of a specific original.
trailing edge (OFF), the ADF controller
computes the time taken by the original to
move past the pre-registration sensor with
Original width detecting volume
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.
ADF controller PCB
Figure 2-204
(FMCK)
Original
Pre-registrationOriginal tray paper detection signal (ENT)Feed motor clock signal
Prism
sensor
U502
Feed motor
BKM2
Registration roller
SR4
Feed motor clock
sensor
Figure 2-203
COPYRIGHT ? 1999 CANON INC. CANON DADF-B1 REV.0 APR. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)2-7 |
ACEC
