Canon NP6218, FY8-13EX-000 service manual Off

CHAPTER 6 FIXING SYSTEM

The fixing film sensor (PS9) is used to detect the position of the fixing film and found at the end of the film.

The rear (sensor side) of the fixing film is provided with a cut as shown in Figure 6- 106 so that the fixing film sensor continuously goes on and off.

Normally, the on and off periods of the sensor are identical as long as the fixing film remains centered.

If the film starts to become displaced toward the rear, however, the on period becomes longer; the off period becomes longer if the film starts to be displaced toward the front. (See Figure 6-107)

The DC controller monitors the on and off periods of the sensor and computes the difference to correct the position of the fixing film.

5

(unit: mm)

Fixing film (rear)

(front)

Tension roller

OFF

Drive roller

ON

Figure 6-106

Normal ON

OFF

(rear) ON OFF

ON

(front) OFF

Figure 6-107

6-8 COPYRIGHT © 1997 CANON INC. CANON NP6218 REV. 0 MAY 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)