| 摘要 |
PURPOSE:To prevent the shadow of a light emitting element which is not shielded by an original from being transferred when transfer paper larger than the original is fed selectively by turning on light emitting element during original size detection and copying operation. CONSTITUTION:When the size of the original is detected, the original P is placed on an original platen 31 along an original positioning ruler 33. When a start switch is turned on, light emitting elements l1, l2, and l3 illuminate and an original platen device 3 moves; and the 1st light emitting element l1 moves to right above the slit 23 of an optical system 2 and is shielded by the original P, so that its light is not sensed by a photodetecting element L. Then, when the light emitting element l2 moves to right above the slit 23, its light is sensed by the photodetecting element L. Further, the light from the light emitting element l3 is also sensed by the photodetecting element L to detect the size of the original P from the number of light emitting elements sensed by the photodetecting element L; when transfer paper larger than the original is fed, shadows of the light emitting elements l2 and l3 which are not shielded by the original P are not transferred as well as the white ground part of the original, thereby obtaining an excellent copy.
|
