Exposure Lamp La1 - Minolta EP1080 Service Manual

12-1. Exposure Lamp LA1

An AC halogen lamp is used as Exposure Lamp LA1.
As the exposure level is adjusted on the control panel, the duty ratio of the
pulse of AVR Remote from PWB-A changes to increase or decrease the LA1
voltage, thereby changing the image density.
Manual EXP Setting
Lamp Voltage
− 8
Difference (V)
SCEND
Transport Roller Sensor PC51
Exposure Lamp LA1
If reduction copies are made using large size paper, the Trailing edge of
*
the first copy moves past PC51 after the SCEND signal for the second
copy has been generated. If LA1 is turned ON for the second copy at the
same timing as the first one, therefore, the image for the second copy is
produced on the trailing edge of the first copy. To prevent this from
occurring, LA1 is turned ON for the second and subsequent copies when
all of the following conditions are met:
•
Approx. 800 msec. or more have elapsed after the first copy deactivated
PC51.
•
The PC51 output is HIGH.
•
The SCEND signal for the second copy is output.
9 8 7 6
− 4 −2 −1
Reference
Approx. 800msec. or more
Image Leading Edge
Approx. 400msec.
1st Copy
M-35
5 4 3 2
+ 1 + 2 + 4
Image Leading Edge
2nt Copy
1139T54MCA
1139C13MAA
1
+ 8