2. Idle Rotation of the Photosensitive Drum and the Developing Cylinder
In a high humidity environment, the photosensitive drum and the developing cylinder
tend to absorb moisture, leading to a lowered copy density and distorted images (as
when the machine is turned on for the first time in the morning).
To prevent such a problem, if the surface temperature of the upper fixing roller is
75°C or less, the photosensitive drum and the developing cylinder are rotated idly during
the wait-up period.
Idle rotation is controlled in ether of three modes according to the vapor ratio
detected by an environment sensor as shown in Table 4-107.
Reference:
The term
vapor ratio
refers to the amount of vapor (g) contained in 1 kg of air.
The control modes shown in Table 4-107 may be adjusted in service mode.
Table 4-107
Reference:
The 100V machines are shipped with the drum heater switch (SW3) set to ON (idle
rotation mode ON).
COPYRIGHT © 1997 CANON INC. CANON NP6350/NP6251 REV. 0 JULY 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)
CHAPTER 4 IMAGE FORMATION SYSTEM
4-24
Vapor ratio
7 g/kg or less
7 to 12 g/kg
12 g/kg or more
Remarks
None
2 to 2.5 min
Up to 5 min
Idle rotation
None
Fixing roller 100°C through warm-up
Power-on through fixing warm-up