Canon imagePRESS C1, Service Manual

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Chapter 7
7-71
F-7-86
2. Full-Color 2-Sheet Continuous Printing (2-image printing) (See after-mentioned note)
PVREQ signal (image demanding signal) for each color is produced based on the A-surface ITB home position detection signal (I_TOP1A) and the B-surface ITB
home position detection signal (I_TOP1B). The image is formed at constant speed based on this PVREQ signal.
The image is formed in order based on I_TOP1A for the first surface, I_TOP1B for the second surface.
F-7-87
2-image printing is the print with image forming by 2 surfaces on the ITB. 2-image printing is available for up to LTR size (sub scanning direction) that is equivalent
to the interval between two home position detection signals.
3. Monochrome Continuous Printing
The image forming position on the ITB is arbitrary because the monochrome printing has single color. The DC controller does not perform the ITB home position
detection at monochrome printing.
After determining the home position by the timer inside the DC controller, PVREQ signal (image demanding signal) is produced. The image is formed based on
this PVREQ signal.
F-7-88
Related Error Code
E070 (ITB HP detection fault error)
xx=01: ITB home position sensor B, xx=02: ITB home position sensor A, only at ITB 1/1 speed, XX=00: No discrimination
00xx: When ITB HP is not detected after the specified period of time passed, there is an error of ITB home position detection sensor
01xx: When the time from the detection of ITB HP to the detection of the next HP is less than the specified time (884msec or less)
02xx: When the time from the detection of ITB HP to the detection of the next HP is more than the specified time (939msec or more)
03xx: ITB HP was not detected only once. ITB home position sensor A/B should have detected alternately, however, the same HP were continuously detected.
7.9.11 ITB Home Position Detection
0020-4177
imagePRESS C1+ (Printer) / imagePRESS C1+
This machine detects the ITB home position to adjust the reading position of the image.
The ITB home position sensor (PS1, PSS2) detects the home position detection surface (two reflecting surfaces) prepared at the end of the ITB to detect the home
position. The following is the operation procedure.
1) When receiving the print instruction, the DC controller turns the ITB. When detecting the reflecting surfaces, PS1 and PS2 send the home position detection
signal respectively (I_TOP_SNS_A, I_TOP_SNS_B) to the DC controller via the side driver PCB.
2) The DC controller determines the sensor detection signal that was first input as the home position (see REMARK) (I_TOPIA), and counts the home position
each time the next reflection surface is detected, such as I_TOP2A, I_TOP3A, I_TOP4A,
3) For 5 full color print, the DC controller produces sub scanning synchronized signal (PVREQ) 5 times based on this signal, send them to the main controller. After
that, the DC controller receives the video data for each color 5 times from the main controller and forms the toner image for each color in order on the specified
position on the ITB.
Start key ON
ON
PRINT INTR
PVREQ
Laser
(image formation)
A-surf
ace
B-surf
ace
Home position
detection signal
Y M C Bk
I_TOP1A I_TOP2A I_TOP3A I_TOP4A
(PS1 or PS2 output)
Start key ON
ON
PRINT INTR
PVREQ
Laser
(image formation)
A-sur
face
B-sur
face
Y Y M M C C Bk Bk
I_TOP1A
I_TOP1B
I_TOP2A
I_TOP2B
I_TOP3A
I_TOP3B
I_TOP4A
I_TOP4B
Home position
detection signal
(PS1 or PS2 output)
Start key ON
ON
PRINT INTR
PVREQ
Laser (image formation)
Home position detection
signal
Bk
I_TOP1A
DC controller inside timer