Contact type image sensor

Abstract

A contact type image sensor including a plurality of photodiodes for converting a light signal into an electric signal according to the intensity of the light and a plurality of blocking diodes, arranged in either a back-to-back or a front-to-front connection with the photodiodes, for functioning as switching elements to have the information stored on the photodiodes read out, and adapted to be driven by a matrix drive system. For a back-to-back connection of the blocking diodes and photodiodes, a control circuit maintains the potential difference between cathodes of the photodiodes at zero volts at all times. Similarly, for a front-to-front connection of the blocking diodes and photodiodes, a control/drive circuit maintains the potential difference between the anodes of the photodiodes at zero volts at all times. Since the potential difference between the cathodes (for the back-to-back connection) or anodes (for the front-to-front connection) of all of the photodiodes is always maintained at zero volts, crosstalk at crossover portions between output lines connected to the photodiodes is reduced.

Dependencies are inferred from the claim text.