Canon FINISHER-C1 Service Manual page 68

CHAPTER 2 FINISHER UNIT BASIC OPERATION
2. Manual Feed Tray Height Control Mode
The height sensor (PS1) is adjusted so that it takes measurements with reference to the light
reflected (diffused) by plain paper. The light reflected by a transparency, however, behaves as if it is
reflected by a mirror, causing the sensor to provide a reading about 30 mm lower than the height of
a plain paper stack-this ultimately causes the machine to control the height of the tray higher than
an optimum height.
To make up for the discrepancy, the height of the tray is controlled as follows during manual
feed pick-up mode, which is believed to be used most often for transparencies.
a. When sheets for manual feed pick-up are stacked on the tray, the optimum height as detected by
the height sensor is lowered by about 30 mm. This way, the tray will be controlled to an
appropriate height when transparencies are stacked. (The height will be lower by about 30 mm
from the optimum height if plain paper is stacked.)
b. The height of the stack will not be adjusted during continuous stacking operation in manual
feed mode. (Because of the limited number of sheets in continuous stacking mode, stacking
will not be hindered without height adjustment.) However, the height of the stack will still be
adjusted at the start of copying operation. Moreover, the height will also be adjusted for sta-
pling operation.
c. The mode ends when cassette pick-up operation starts after removal of all paper from the tray.
The mode resumes when manual feed pick-up operation start once again.
Reference:
If the tray is controlled to a lower height when plain paper is stacked, sheets of certain special types or
sizes can jam easily. To avoid such a problem, the machine is designed so that the manual feed tray
height control mode may be disabled. For instructions, see Chapter 6.
2-38
Figure 2-250
COPYRIGHT © 1998 CANON INC. FINISHER-C1/SADDLE FINISHER-C2 REV. 0 DEC. 1998 PRINTED IN JAPAN (IMPRIME AU JAPON)
Height sensor (PS1)
Paper