Specifications

1.2 DIRTY BACKGROUND
- Phenomenon -
1. Dirty background at image density level 4 (manual setting)
2. When newspapers are copied, the background is dirty even at level 7.
3. ADS copies have a dirty background.
- Possible Causes -
1. Dirty optics
2. Toner scattering
• High toner density
• The inlet seal of the development unit is stripped off.
• The doctor gap is too wide.
3. The exposure lamp is not bright enough. This may be caused by
deterioration of the exposure lamp or low lamp voltage.
4. In ADS mode, Vde (reflected light from the original) is too high.
5. The ADS optical fiber is cut or bent.
6. The development bias is grounded.
1 December 1990
6-4