| 摘要 |
PURPOSE:To prevent the malfunction of a copying speed controller which is caused by the disturbance light, by controlling the quantity of projection to ensure a constant voume of light received by a receiver. CONSTITUTION:A copying speed controller consists of a light receiver 4 which receives the light passed through an original 2 and a filter 3 and transmits the signals according to the volume of the received light, a comparator 5 which receives the signal from the receiver 4 and then compares the signal with the prescribed value to deliver the difference, a controller 7 which controls a driving deivce 8 to obtain a copying speed according to the volume of projected light, etc. The original 2 is put on a paper feed table 9, and the light volume of a projector 1 is controlled by a controller 7 while looking at an indicator 6 so that the output of the comparator 5 is set at O. Thus the device 8 is controlled to obtain a copying speed corresponding to the volume of projected light. In such a way, the malfunction of the controller caused by the disturbance light can be prevented. |
