Ricoh Robin Service Manual page 36

24 June 1994
3.6 EXPOSURE LAMP VOLTAGE CONTROL
The main board controls the exposure lamp voltage through the ac drive
board. The exposure lamp voltage is based on the base lamp voltage and
various correction factors. The method of control is different depending on
whether the image density is manually selected or the auto image density
mode is selected.
The exposure lamp voltage consists of the following factors:
Exposure lamp voltage = Base exposure lamp voltage
3.6.1 Base Lamp Voltage In Manual Image Density Mode
Manual ID Level
Exposure Lamp Data
The above table shows changes in the exposure lamp data in the manual
image density mode.
SP48 sets the exposure lamp data for level 4 (Vo) of manual image density
mode. A value from 100 to 150 can be selected.
3.6.2 Base Lamp Voltage In Auto Image Density Mode
In the auto ID mode, the CPU selects the level 4 (Vo) exposure lamp data
(SP48) regardless of the input from the auto image density sensor.
(Manual or auto image density mode)
+
V correction factor
L
+
Reproduction ratio correction factor
(A152 copier only)
Darker
1 2 3
Vo –4 Vo –4 Vo –2
2-17
4 5 6
Vo ±0
Vo+2 Vo+2
OPTICS
Lighter
7
Vo+4