Introduction - Ricoh FT7770 Service Manual

30 April, '89
QUENCHING

1. Introduction

Quenching involves two steps.
the drum. This neutralizes any negative charge remaining on the drum from
the pre-cleaning corona.
charge. Two steps are required because the quenching lamp is less effective .
against negative charges than positive charges.
The quenching lamp also stabilizes the drum sensitivity from the first cycle
by pre-illuminating (pre-fatiguing) the drum.
This machine uses a cold cathode lamp (sometimes called cold fluorescent
lamp) as the quenching lamp.
watts) has characteristics of low power consumption and low heat output
combined with strong light output.
(Front View)
First, the PQC applies a positive charge to
Then, the quenching lamp neutralizes the positive
The cold cathode lamp (ac 485 volts, 1.46
2-58