| 摘要 |
PROBLEM TO BE SOLVED: To secure the detection accuracy of the end position of sheets even if the vertical position of the sheets is not specified. SOLUTION: In a sheet detection sensor 51, light from a line-like light emitting element 54 is shielded by a recording paper P and not injected into a light receiving element 55 just below the recording paper P, and injected only in light receiving elements 55 coming out of just above the recording paper P. Also, the light passed through near the end part of the recording paper P is injected only in the light receiving elements 55 just below near the end part of the recording paper P, and is not injected into the other light receiving elements 55. In addition, even if the position of the recording paper P is displaced vertically, the positions of the light receiving elements just below near the end part of the recording paper P are kept unchanged, and the light passed through near the end part of the recording paper P is injected only into these light receiving elements. Namely, even if the position of the recording paper P is displaced vertically, the position of the end part of the recording paper P can be accurately detected. COPYRIGHT: (C)2005,JPO&NCIPI
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