Canon imageRUNNER ADVANCE C5255 Series Service Manual page 102

2
Technology > Image Formation System > Controls > Image stabilization control
● Drum film thickness detection
To detect use condition of the photosensitive drum
Execution timing
1) At power-on
2) At recovery from sleep mode
3) At last rotation on a specified print basis
Control description
1) The drum count value is calculated by the monitor signal of the primary charging AC bias.
2) The count value calculated in step 1) above is added to the drum count value that has been
kept in SRAM.
3) The latest count value determined in step 2) above is classified to be one of the 10 levels
as the drum film thickness detection data.
4) The determined data is compared to the existing drum film thickness detection data kept in
the other area in SRAM. If there is any difference between both data, the newly-determined
data is overwritten on SRAM as the latest drum film thickness detection data. If there is no
difference in both data, the newly-determined data is not overwritten, but disposed.
Y M C
Photosensitive
drum
Primary charging
roller
MEMO:
Bk Drum for highly-durable type, the drum is no shave.
Therefore, Bk drum is not the thickness detection.
The result of drum thickness detection is reflected to the following data.
• Developing bias
• Primary transfer bias
• ATR patch detection result
• Laser output
2 Technology > Image Formation System > Controls > Image stabilization control
DC controller
(UN1)
SRAM(IC2)
Drum count
data
Y
M
C
Bk
Drum film
Monitor signal
thickness data
HVT1
(UN16)
Primary charging
AC bias
Y
M
drive signal
C
F-2-92
2-64
2-64