To prevent interference between a paper ejection detecting system and a stack detecting system, and also to precisely exert, for example, paper ejection control after image formation and shift control thereof.
A sheet processor comprises: an ejection part 35 configured to eject paper onto a paper stacking tray 61; a paper ejection detecting sensor 11 having a light emitting part and light receiving part 11b and configured to detect a rear end of paper ejected on the paper stacking tray 61; a paper ejection control part 51 configured to control the ejection speed of paper based on a paper ejection detection signal; a stack detection sensor 12 having a light emitting part and a light receiving part arranged opposite to each other along the width direction of the paper stacking tray 61 and configured to detect, at a predetermined position, the upper end of sheets of paper stacked on the paper stacking tray 61; and a stack control part 62 configured to raise or lower the paper stacking tray 61 based on a stack detection signal obtained here and to adjust a paper fall step, between a paper ejecting position and a paper stacking position, to a predetermined distance. The light receiving part 11b is provided with a filter 40 for removing interference between the paper ejection detecting system and the stack detecting system.
YAMANE HIDEO
SUGIMOTO EIJI
| JPH11116102A | 1999-04-27 | |||
| JP2001335236A | 2001-12-04 | |||
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| JP2001226021A | 2001-08-21 | |||
| JPH11116102A | 1999-04-27 |