Ricoh FT4460, Service Manual, Page: 61 / 413

28 February 1989
3. OPTICS
3.1 OVERVIEW
During the copy cycle, an image of the original is reflected onto the drum sur-
face via the optics assembly as follows.
Light Path:
Exposure Lamp [A] –> Original [B]
–> 1st mirror [C] –>
–> 2nd Mirror [D] –> 3rd Mirror [E] –> Lens [F]
–> 4th Mirror [G] –> 5th Mirror [H] –> Red erase [I] –>
–> 6th Mirror [J]
–> Toner shield glass [K] –> Drum [L]
The cooling fan [M] removes warm air (heated by the exposure lamp) from
the optics cavity. This blower operates during every copy cycle.
The 1st scanner (lamp and 1st mirror), 2nd scanner (2nd and 3rd mirrors),
3rd scanner (4th and 5th mirrors), and the lens function together to achieve a
wide range of reproduction ratios.
The red erase unit [I] has a green filter and a red filter. The green filter is used
in the normal copy mode. The red filter is used in the red erase copy mode.
Auto density sensing (ADS) and auto original paper size sensing (APS) are
done by optical fibers located on the 1st scanner unit.
A thermoswitch (opens at 130°C)installed on the back of the exposure lamp
reflector keeps temperatures at acceptable levels inside the optics assembly.
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