Image sensor, reading circuit thereof and pixel structure

Abstract

The invention discloses an image sensor, a reading circuit thereof and a pixel structure. The reading circuit comprises an analog-to-digital conversion circuit which is coupled with a pixel circuit ofthe CMOS image sensor and is suitable for quantifying an output signal of the pixel circuit to obtain a corresponding digital signal; and a conversion gain control circuit, coupled with the pixel circuit and suitable for generating a corresponding pixel circuit control signal based on the swing amplitude of the signal output by the pixel circuit when the signal output by the pixel circuit is an image signal so as to control the conversion gain of the pixel circuit. By applying the scheme, the dynamic range of the image sensor can be expanded.

Description

technical field [0001] The invention relates to the field of image sensors, in particular to an image sensor, a readout circuit, and a pixel structure thereof. Background technique [0002] A Complementary Metal Oxide Semiconductor (CMOS) image sensor is a semiconductor device that converts optical signals into electrical signals. Generally, a CMOS image sensor includes a pixel array, a pixel readout circuit array coupled to the pixel array, and a digital processing circuit. Wherein, the pixel array is composed of several pixel circuits distributed in an array, and the pixel readout circuit array is composed of several readout circuits distributed in an array. [0003] Pixel circuits in the same column are output by the same bit line, and are coupled to a readout circuit. The pixel array converts the received optical signal into an analog electrical signal, and the readout circuit array converts the analog electrical signal into a digital electrical signal, which is then o...

AI Technical Summary

Problems solved by technology

[0005] However, the dynamic range of existing CMOS image sensors is still low and cannot meet the requirements for image quality

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