Uneven Exposure Adjustment - Ricoh FT5540 Service Manual

31 August 1989

7.4 Uneven Exposure Adjustment

When: The exposure is uneven.
To maintain even exposure.
Purpose:
The side-to-side variation of the gray scales on the test chart should
Target:
be less than one level.
Exposure adjustment plate positioning
Measure:
How: Changes the position of the adjustment plates to make the light
intensity from the exposure lamp even across its length.
1. Clean the optics and the charge corona wires.
2. Place a test chart on the exposure glass and make three A3/LDG copies.
3. If the side-to-side variations of the gray scales is not within specifications, turn off the main
switch and remove the exposure glass. (Refer to "Exposure Glass Removal.")
4. Position the adjusting plates [A] so that the copy image meets the adjustment standard.
The leading edges of the three adjustment plates must be aligned [B] to avoid white
streaks.