TM 5-6675-324-14
b. Blank exposure.
Whenever the drum is rotating but a copy is not being scanned, the blank exposure
shutter is opened to let light from the lamp illuminate the drum. This keeps the
CdS resistivity low and prevents the buildup of positive charges on the surface. If
there are no positive charges on the drum, developer will not be attracted to it.
Thus, the drum is kept clean and developer waste minimized.
c.
Blank strip exposure.
Whenever the drum is revolving, a narrow strip of the surface is illuminated by
light from the halogen lamp that passes through the blank strip exposure window.
This illuminates a band around the drum and keeps the band free of developer buildup
even when the shutter is closed. This allows the separation belt to function
properly.
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