Specifications

➄
AE Sensor Gain Adjustment
The output from the AE Sensor which detects the original image density
in the Auto Exposure mode varies depending on the intensity of the LA1
light. The AE Sensor gain is therefore adjusted in proportion to the
setting (or correction) of the optimum Exposure Lamp voltage.
The AE Sensor gain can be varied by the pulse signal (pulse width)
output from pin 9 of IC1A on Master Board PWB-A. The following two
different types of controls are provided.
(1) The AE Sensor gain is adjusted when the F5 operation is run.
Control
When the F5 operation is run, the optimum Exposure Lamp voltage is
set (corrected).
LA1 is turned ON to illuminate a blank sheet of paper placed on the
Original Glass with an optimum Exposure Lamp voltage.
The AE Sensor output voltage is applied to pin 1 of IC1A on Master
Board PWB-A.
The AE Sensor gain is varied so that the above voltage becomes 1.8V
and the pulse signal (pulse width) is finally selected that has resulted in
the gain nearest to 1.8V within the range of ±0.5V.
LA1 is turned ON to illuminate the halftone patch on the back of the
Original Width Scale with the optimum Exposure Lamp voltage.
The AE Sensor output voltage is applied to pin 1 of IC1A and stored in
memory. ... A
(2) The AE Sensor gain is corrected as necessary when the Exposure
Lamp voltage is corrected (by (3) or (4) of
➃
), thereby maintaining the
appropriate AE control.
Control
After the exposure correction has been made, LA1 is turned ON to
illuminate the halftone patch on the back of the Original Width Scale
with the Exposure Lamp voltage which has undergone the correction.
The AE Sensor output voltage is applied to pin 1 of IC1A on PWB-A.
The AE Sensor gain is adjusted so that the above voltage becomes the
voltage value stored in memory when F5 was run and the pulse signal
(pulse width) at that time is taken.
1075C52MAA
M-23