Image sensor having unit light receiving circuit with sample-and-hold means

摘要

To eliminate a residual image due to residual charge in an image sensor circuit and provide an effective bright-time output, the image sensor is provided with a reset switch connected to a photodiode. After the potential of the photodiode is held through a first amplifier in two holding circuits as an image signal and an initial signal, the initial signal and the image signal are sequentially output through a second amplifier. By resetting the photodiode to a desired potential to produce an initial signal, a residual image can be eliminated.