Active pixel sensor circuit, driving method and image sensor

Abstract

The invention provides an active pixel sensor circuit, a driving method and an image sensor. The active pixel sensor circuit comprises a light sensing device, a first storage capacitor, a second storage capacitor, a source follow-up transistor as well as a resetting module, a compensation control module and a signal reading control module, wherein a charge control module is adopted to control a second electrode of the light sensing device to be connected with a second end of the second storage capacitor in a resetting period and a charge period, and to control the grid of the source follow-up transistor to be connected with a second electrode of the source follow-up transistor in the charge period; and the compensation control module is used for controlling a second end of the second storage capacitor to be connected with a second end of the first storage capacitor in the resetting period and a compensation period. By adopting the active pixel sensor circuit, the problem that output current of the source follow-up transistor is not accordant because of differences of self is solved, and the output current is not related to the threshold voltage of the source follow-up transistor.

Description

technical field [0001] The invention relates to the technical field of active pixel sensing, in particular to an active pixel sensor circuit, a driving method and an image sensor. Background technique [0002] CMOS (Complementary Metal-Oxide Semiconductor), Complementary Metal-Oxide Semiconductor) image sensor can convert the function of pure logic operation into electrical energy after receiving external light and transmitting it. [0003] As the detection circuit of the most common CMOS image sensor, the active pixel sensor (ActivePixelSensor, referred to as APS) circuit is in the photoelectric conversion process of the photosensitive device, due to the source follower TFT (ThinFilmTransistor, thin film transistor) The end output caused by the process difference The current is not uniform, and the output current of the source-follower TFT will be affected by its own threshold voltage, which will cause the final picture to be distorted. Contents of the invention [0004]...

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Problems solved by technology

[0004] The main purpose of the present invention is to provide an active pixel sensor circuit, a driving method and an image sensor to solve the problem caused by the process difference of the source follower TFT itself during the photoelectric conversion process of the existing active pixel sensor circuit. The output current at the end of the TFT is not uniform, and the output current of the source follower TFT will be affected by its own threshold voltage, which will cause the final picture to be distorted.

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