| 摘要 |
PROBLEM TO BE SOLVED: To provide an original paper size detecting device which is prevented from erroneously detecting a user's hand and other object as an original paper and whose reliability is high by plurality and independently providing original paper size sensors having the same detecting function in the length direction and the width direction in parallel and synthetically judging the information from the sensors, so that the original paper size is decided. SOLUTION: The original paper size sensors are plurality and independently arranged in parallel. Namely, a length sensor 17 is obliquely arranged in the center part in a scanning direction on a contact glass 8, and a width sensor 18 is arranged at one end. The width sensor 18 is irradiated with a beam from an LED 19 in three directions and the beam is received by three photodetectors 20 (three-beam system). Therefore, three points can be detected by one sensor 18, and the device can cope with the narrow space. When an opening/closing sensor is turned on, the on/off of the original paper size sensor (length 17 and width 18) is combined so as to decide the original paper size. |
