Ricoh FT4460, Service Manual, Page: 345 / 413

28 February 1989
1.4 UNEVEN IMAGE DENSITY - 2
- Phenomena -
1.
2.
Uneven image density appears in the copy background, but not in the
solid black area.
Areas where the image density is uneven move when the reproduction
ratio is changed.
- Possible Causes -
1. The size of the dirty area can be used to determine which optics unit
components are dirty. Refer to illustrations (1) and (2) below.
(1)
(2)
Exposure Glass, Reflector 4 t h M i r r o r , 5 t h M i r r o r
1st Mirror, 2nd Mirror
6th Mirror, Red/Green Filter
3 r d M i r r o r Toner Shield Glass
NOTE: If the uneven area does not move when the reproduction ratio is
changed, the problem is not with the optics unit.
2. Deterioration of the exposure lamp or an incorrectly aligned filament.
- Actions -
1.
2.
Clean the optics unit
Clean the mirrors, lens, and reflector with a cloth.
Clean the exposure glass with water or alcohol.
Clean the toner shield glass with a dry cloth or one dipped in alcohol.
Clean red erase filters with a blower brush (replace when fogged or
scratched).
Check the exposure lamp. If the lamp is not discolored, adjust the
exposure lamp position. (See the section on exposure lamp adjustment.)
NOTE: After cleaning the mirrors or the exposure glass, adjust the ADS and
the exposure lamp voltage to achieve the proper image.
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