CMOS (Complementary Metal-Oxide-Semiconductor) image sensor

Abstract

The invention provides a CMOS (Complementary Metal-Oxide-Semiconductor) image sensor in which a first polarizer, a liquid crystal layer with a transparent electrode structure, and a second polarizer, are all additionally arranged on a light-sensitive component, and the arrangement of the liquid crystals between can be changed by controlling the voltage of the transparent electrode so as to control the on and off of light. A light on-off structure is added in pixel structures in the CMOS image sensor, the light on-off structure can independently control the exposure integral time of each pixel structure and also can simultaneously expose all or part of pixel structures or simultaneously stopping exposing, thereby realizing a global exposure function without influencing a filling rate of the image sensor, and the integrated level of devices is improved. Moreover, the added light on-off structures can substitute the conventional shutter apparatus, so that the volume of the light-sensitive devices is reduced.

Description

technical field [0001] The invention belongs to the field of semiconductors, in particular to a CMOS image sensor. Background technique [0002] A CMOS image sensor is a semiconductor device manufactured using a CMOS manufacturing process that converts an image's optical signal into an electrical signal for transmission and processing. A CMOS image sensor generally consists of a photosensitive area and a signal processing circuit. A common CMOS image sensor at present is an active pixel image sensor (APS). [0003] Existing CMOS image sensors include CMOS digital-analog circuits and pixel unit circuit arrays. According to the number of transistors included in one pixel unit circuit, existing CMOS image sensors are divided into 3T-type structures and 4T-type structures, and 5T-type structures can also be used. type structure. [0004] Such as figure 1 As shown, it is an equivalent circuit structure diagram of a pixel unit circuit of an existing 3T-type structure CMOS imag...

AI Technical Summary

Problems solved by technology

However, this kind of shutter device is the same as the traditional mechanical shutter. For the CMOS image sensor with the traditional structure, it cannot guarantee the simultaneous exposure of all pixels, nor can it realize the simultaneous exposure of some pixels, which will cause each or every row and column of pixels There is a large difference in the photosensitive time integral difference of the point, and the global exposure of the device cannot be realized, which is not conducive to the improvement of the photosensitive accuracy of the sensor.

Moreover, the installation of this liquid crystal shutter also increases the volume of the sensor, which is also unfavorable for the demand for decreasing device volume.

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