Amplifier circuit and image sensor using amplifier circuit

摘要

There is a problem that in an image sensor including an amplifier in each pixel, when a thin-film semiconductor is used as a transistor constituting the amplifier, voltage continues to be applied between source and gate of the transistor and thereby a threshold voltage value of the transistor varies, resulting in a variation of signal voltage. To solve the problem, a thin-film transistor formed with an oxide semiconductor is used as the transistor constituting the amplifier, and during a period other than a period of outputting an output of the amplifier, source potential of the transistor is controlled to be equal to drain potential thereof.

主权项

1. An amplifier circuit outputting current in accordance with voltage applied to an input terminal thereof, the amplifier circuit comprising:
at least one transistor including a gate terminal connected to the input terminal and a source terminal connected to an output terminal of the amplifier circuit, wherein the amplifier circuit performs an operation including an output period of outputting a signal and a stop period of outputting no signal, wherein during the stop period, a controller controls potential of the source terminal of the transistor to be equal to potential of a drain terminal of the transistor and potential of the drain terminal of the transistor is always higher than potential of the gate terminal thereof.