G. Cleaning the Primary Charging Wire
1. Outline
The machine is equipped with an automatic cleaning mechanism for the charging
wire of the primary charging assembly which is executed when the following conditions
are met:
• The surface temperature of the fixing roller at power-on is 100°C or less.
• The automatic cleaning mechanism is executed in user mode. (p. 1-17)
• Last rotation (LSTR) initiated every 2,000 copies ended. (If cleaning has been
executed under the foregoing two conditions, cleaning will be executed every 2,000
copies thereafter.)
2. Automatic Cleaning Mechanism
If the surface temperature of the fixing roller is 100°C or less at power-on, the primary
charging wire cleaner motor (M12) rotates clockwise to move the cleaner forward for
about 20 sec. The cleaner motor then rotates counterclockwise to move the cleaner in
reverse for about 16 sec. (The machine is not equipped with a position sensor.)
The RAM on the DC controller PCB keeps track of the cleaning operations so that
cleaning is executed every 2,000 copies. (In the case of continuous copying, cleaning
will be executed when as many copies as set have been made.)
Figure 4-123
Primary charging assembly
Wire
Feeding screw
DC controller PCB
Wire cleaner
(rear)
(front)
Primary charging wire cleaning motor (M12)
(PCLM) J103B-3.4
Primary charging wire cleaning motor drive command
COPYRIGHT © 1997 CANON INC. CANON NP6350/NP6251 REV. 0 JULY 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)
CHAPTER 4 IMAGE FORMATION SYSTEM
4-25
