Faulty Pickup Jam - Canon LBP-CX Series Service Manual

For detecting jams, a photointerrupter senses whether print paper has reached or passed through a given
point within a specified time. The sensor signal informs the microcomputer on the DC controller of the presence
or absence of print paper or a jam. As can be seen in Figure 3-28, there are two paper detection photointerrupters
to detect the following three types of jam:
Jam type
Condition
Faulty pickup (delay) The print paper does not reach the pickup sensor (PSI) within the specified
time after the DC controller outputs a TRUE CASSETTE PICKUP ROLLER
CLUTCH SOLENOID DRIVE command (CPUSD). (See Fig. 3-29.)
Outlet delay jam
The print paper does not reach the delivery sensor (PS3) within the specified
time after the DC controller receives a TRUE VSYNC signal. (See Fig. 3-30 and
3-31.)
Outlet stationary jam The print paper does not pass through the delivery sensor (PSI) within the
specified time after the DC controller receives a TRUE VSYNC signal. (See Fig.
3-32 and 3-33.)
Table 34
a. Faulty pickup jam (delay)
Notes:
Time (sec.I
PRINT command
(PANT)
Print request status
(PTRQ)
VERTICAL SYNC REQUEST
command
(VSREQ)
VERTICAL SYNC pulse
(VSYNC)
Cassette pickup
roller clutch solenoid
SL3 (CPUSD)
Pickup sensor PS1
(PFS)
15
Fault
I
ot
1
3.9 sec.
Check for first print Check for second print
- If the external device transmits a TRUE PRNT command to the DC controller within 4 seconds after the
leading edge of a TRUE VSYNC signal, the DC controller does not output PTRQ.
This timing chart is for .an A4 print. Jam detection timing (about 3.9 seconds after CPUSD) is the same for
other sizes.
Figure 3-29 Faulty pickup jam for cassette feed
3-28
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BY CAllOll lllC. CAllOll LBP-CX SERIES REY.2 JULY 1985 PRlllTEO Ill JAPAll (IMPRIME AU JAPOll)