| 摘要 |
PURPOSE:To provide an image sensor which is inexpensive, is capable of performing an image discrimination to some degree, easily performing the adjustment of gain and realizing miniaturization. CONSTITUTION:This sensor is provided with a light emitting diode 201 irradiating an original image with light, a phototransistor 202 receiving Wreflection light from the original image and perforaming a photoelectric conversion, an amplifier 203 amplifying the analog signal from the phototransistor 202, a time constant circuit 110 inputting the analog signal outputted from the amplifier 203 and delaying the signal by prescribed time, an amplifier 209 inputting the analog signal outputted from the amplifier 203 and the analog signal delayed in the time constant circuit 110 and performing a differential amplification and a NOT gate 210 inputting the analog signal outputted from the amplifier 209 and outputting digital signals of '0' and '1' according to the positive and negative values of the analog signals. |
