Wide dynamic range CMOS image sensor pixel unit circuit

Abstract

The invention discloses a wide dynamic range CMOS image sensor pixel unit circuit. The pixel unit circuit comprises a pixel integral circuit and an integral time control circuit; the pixel integral circuit comprises a photodiode diode, an integral signal control transistor M1, a reset signal control transistor M2, a source follower transistor M5, a column selection transistor M8 and an integral capacitor Cint, wherein the integral time control circuit comprises a voltage comparator CAMP, a coarse positioning time-voltage coded signal generator, a precise positioning time-voltage coded signal generator, a coarse positioning time-voltage coded pulse read-in circuit, and a precise positioning time-voltage coded pulse read-in circuit. The pixel unit circuit structure disclosed by the invention has an exposure time self-adaptive characteristics, the dynamic range of the CMOS image sensor can be effectively broadened, the problems that the travelling picture is glare, dazzling and unclear since the fixed exposure time of the traditional automobile data recorder CMOS image sensor causes the over exposure are solved.

Description

technical field [0001] The invention relates to a CMOS image sensor pixel unit circuit, in particular to a wide dynamic range (Wide Dynamic Range, WDR) CMOS image sensor pixel unit circuit applied to a driving recorder. [0002] technical background [0003] The image quality of the driving recorder is affected by a variety of external environments, such as road conditions, weather conditions, ambient light (night street lights, driving lights), etc.; in order to obtain satisfactory image quality, this requires the driving recorder in the image resolution It has better performance in terms of rate and detail rendering. Dynamic range DR (Dynamic-Range) is one of the main performance indicators of image sensors, which is defined as the ratio of the maximum non-saturated signal that the sensor can perceive to the minimum detectable signal. As the dynamic range of the photoreceptor is higher, the light source signal to be collected can be projected onto the photoreceptor more tr...

AI Technical Summary

Problems solved by technology

The pixel unit circuit structure has the characteristics of self-adaptive exposure time, which can effectively expand the dynamic range of the CMOS image sensor, and solve the problem of dazzling, glare, and unclear driving pictures caused by overexposure caused by the fixed exposure time of the CMOS image sensor of the traditional driving recorder.

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