| 摘要 |
PURPOSE:To increase the reading rate of a normal signal by providing a couple of photosensor arrays for a common wiring group constituted on an insulating substrate, obtaining two signals from one point on an original, and then comparing those signals with ach other. CONSTITUTION:For a common side wiring group 4 constituted on an insulating substrate, a couple of photosensor arrays 1 and 2 are formed at the same time so that they have exactly the same characteristics. The photosensor arrays 1 and 2 are provided with individual side wiring groups 6 and 7. An optical system 3 is arranged in such a way that light with the same quantity strikes the photosensor arrays 1 and 2. The common side wiring group 4 and individual side wiring groups 6 and 7 are switched simultaneously by respective driving circuits 5, 8 and 9. Sample holding circuits 10 and 11 input the same information from the photosensor arrays. A comparator compares the signals of the circuits 10 and 11 with each other and permits an analog multiplexer 13 to select one of two pieces of information with a higher or lower level. Consequently, a normal signal is outputted without reference to a fault of the photosensors. |
