Introduction - Ricoh FT7770 Service Manual

30
April, '89
ERASE

1. Introduction

After passing the charge corona unit, the surface of the drum is covered
with a uniform positive charge.
to produce the copy.
the cleaning unit, the erase unit removes the charge potential from the
areas that will not be used. Prior to exposure, it illuminates and dissipates
the surface charge on the sections that are outside the image area.
The erase unit consists of a PCB with a row of 88 LEDs and 11 registers
mounted in a plastic casing.
of the spectrum. The drum is most sensitive to the yellow-green light band
(wavelength).
However, the entire surface is not needed
To reduce toner consumption and reduce the load on
The LEDs emit light in the yellow-green part
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