Outline Of Operations; Outline - Canon NP6251 Service Manual

I. OUTLINE OF OPERATIONS
A. Outline
The upper roller, lower roller, and delivery roller of the fixing assembly are driven by
the main motor through clutches. (See Figure 6-101.)
The upper roller has two built-in heaters: after power-on, the sub heater is turned on
only during WMUP, and the main heater is turned on and off during WMUP and during
subsequent periods for temperature control. (See Figure 6-103.)
The surface temperature of the upper roller is monitored by the main thermistor
(TH1), and the DC controller PCB controls it so that it remains a specific temperature
(target value).
The web used to clean the upper fixing roller is of a one-way clutch type, and is
operated by the fixing cleaning belt drive solenoid (SL14).
A message is indicated in service mode on the control panel when the fixing web
drive solenoid (SL14) has operated 250,000 times. The cumulative count of how many
times the fixing web drive solenoid has operated can be checked in service mode (*6*;
'WEB').
The cleaning belt detecting lever remains in direct contact with the cleaning belt, and
shifts as the cleaning belt is taken up, causing the control panel to indicate 'E005' when
it blocks the sensor (PS11).
The delivery assembly is equipped with a delivery paper deflecting plate. In two-
sided/overlay copying, the DC controller PCB generates the delivery flapper solenoid
drive signal to turn on the delivery flapper solenoid (SL2) so that the delivery flapper
operates to forward copy paper to the holding tray.
The drive of the fixing cleaning belt drive solenoid (SL14) is used to trigger the
external delivery sensor (PS10).
COPYRIGHT © 1997 CANON INC. CANON NP6350/NP6251 REV. 0 JULY 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)
CHAPTER 6 FIXING SYSTEM
6-1