| 摘要 |
PURPOSE:To detect the size of an original without distinguishing between the original and the rear surfaces of an original platen by moving a support member provided with an original detecting means to the trailing edge of the original with an original cover open when the original is placed on the original platen. CONSTITUTION:When the original cover 13 is opened and the original 1 is set on the original platen 12 with a limit switch 4 on, an original detecting sensor 7 detects it, the sensor 7 being composed of a light emitting element 7a and light receiving element 7b; in which are protrusively arranged on the central part of the support member 9 mounted on a illumination unit 10, a unit 10 move toward the trailing edge of the original, and stops after detecting the trailing edge. The length of the original can be detected from the turning angle of a moving motor, and the width can be detected by a sensor 6. When the cover 13 is closed, it is difficult to distinguish between the white rear surface and the white original; however, since detection is made with the cover open, it is easy to distinguish, and a threshold value can be roughly adjusted. |
