High-dynamic CMOS pixel unit and a signal collection method thereof

Abstract

The invention provides a CMOS pixel unit and a signal collection method thereof. The CMOS pixel unit is characterized in that a positive electrode of a photosensitive diode is connected with a negative electrode of a power source, a strong light processing circuit is connected with a drain electrode of a first NMOS tube and a source electrode of a second NMOS tube and is used for adding a storage capacitance for an electric signal when the photosensitive diode is irradiated by strong light, the positive electrode of an array current source is connected with the drain electrode of a third NMOS tube and serves as a signal output end of the high-dynamic CMOS pixel unit, the negative electrode of the array current source is connected with the negative electrode of the power source, the source electrode of the first NMOS tube is connected with the negative electrode of the photosensitive diode and is used for conducting the photosensitive diode, the source electrode of the second NMOS tube is connected with the drain electrode of the first NMOS tube, the drain electrode of the second NMOS tube is connected with the positive electrode of the power source and is used for realizing restoration of an output signal, and the source electrode of the third NMOS tube is connected with a strong light processing circuit and is used for realizing selective connection of each pixel unit and an array output end.

Description

technical field [0001] The invention relates to the technical field of image sensors, in particular to a high dynamic CMOS pixel unit and a signal acquisition method thereof. Background technique [0002] CMOS image sensor has experienced rapid development in recent decades, and its technology has become more mature. With its advantages of low power consumption, low cost and high performance, it has been widely used in many fields such as consumer electronics, monitoring, military and aerospace. At the same time, with the development of the times, higher requirements are also put forward for CMOS image sensors. [0003] The dynamic range of human vision is as high as 200dB. The higher the dynamic range of the CMOS image sensor, the more information the image provides, and the closer the image is to the vision of the human eye. Therefore, a high dynamic range CMOS image sensor is needed in the industry. The dynamic range of the output image of the traditional 4TCMOS pixel u...

AI Technical Summary

Problems solved by technology

The dynamic range of the traditional 4TCMOS pixel unit is not high in one exposure output image. High dynamic images can be achieved by combining images with multiple exposures, but it involves complex digital algorithms and will reduce the frame rate

Another method is to logarithmically output CMOS pixel units, but it has the problems of large process deviation of each pixel unit and poor pixel output consistency, making it difficult to achieve high-resolution applications

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