Canon imageRUNNER ADVANCE C5255 Series Service Manual page 74

2
Technology > Laser Exposure System > Various Controls > APC (Auto Power Control) control
Print instruction
Reference
signal
Video request signal
(PVREQ)
T1
About15ms
Video signal
(VDO)
About15ms
2 Technology > Laser Exposure System > Various Controls > APC (Auto Power Control) control
T2
Y
M C Bk
■ APC (Auto Power Control) control
● Purpose
This is to make the laser light for 1 line consistent amount.
● Execution timing
Per each line (before image writing)
● Execution time
Approx. 2 µs
F-2-53
● Control details
1) DC Controller outputs the laser control signal to the Laser Driver IC on the Laser Driver
PCB.
2) APC mode is specified to the Laser Driver IC and it forcibly emits the laser diode of each
color. At the same time, each laser driver IC monitors the laser diode (LD) on the photo
diode (PD) and adjusts the output of laser diode until the light intensity becomes consistent
amount.
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