Image sensor pixel structure and control method thereof

Abstract

The invention provides an image sensor pixel structure and a control method thereof. The image sensor pixel structure comprises a photosensitive control unit, a storage unit, a reset unit and an output unit. One end of the photosensitive control unit is grounded, the other end is connected with one end of the storage unit, and the photosensitive control unit is used for converting periodically exposed optical signals generated by the light source into electric signals and transmitting the electric signals to the storage unit; the other end of the storage unit is connected with one end of the reset unit and one end of the output unit and used for storing electric signals; the other end of the reset unit is connected with a power supply, and the photosensitive control unit and the storage unit are reset by adopting a reset signal; and the other end of the output unit outputs an electric signal and a reset signal. According to the invention, the storage unit is used for storing the electric signal during exposure, thereby facilitating the elimination of LED flicker, i.e., achieving the LFM, guaranteeing the LFM, improving the image noise performance, and improving the noise performance of an image.

Description

technical field [0001] The invention relates to the field of image sensors, in particular to an image sensor pixel structure and a control method thereof. Background technique [0002] With the continuous development of image sensor technology, CMOS image sensors are more and more widely used in electronics, monitoring, navigation, transportation and other fields due to their advantages of high integration and low power consumption. However, with the continuous development of CMOS image sensor technology, the requirements for the performance of the CMOS image sensor are also getting higher and higher. In the field of vehicle intelligent driving, the performance requirements of CMOS image sensors are higher. [0003] For the camera for vehicle-mounted intelligent assisted driving, since the camera must be able to accurately detect all signal lights, car lights and other information within the field of vision, and the light source of signal lights and car lights is LED light ...

AI Technical Summary

Problems solved by technology

[0003] For the camera for vehicle-mounted intelligent driving assistance, since the camera must be able to accurately detect all signal lights, car lights and other information within the field of view, and the light source of signal lights and car lights is LED light source, LED light source is a pulse light source, for ordinary rolling shutter exposure When the vehicle-mounted camera captures the LED signal, the signal will be incomplete, resulting in signal acquisition errors and assisted driving errors. Therefore, a very important functional requirement of the vehicle-mounted camera is LFM (LED Flicker Mitigation, LED flicker suppression)

[0004] Existing LFM technology either requires multi-frame signal fusion, or requires multiple signal reads for a single line in a single frame to increase the line period, both of which will reduce the frame rate

However, the current LFM technology that does not lose the frame rate at all stores the segmented signal in the floating diffusion area. When reading the signal, it is necessary to read the exposure signal first and then read the reset signal. The signal is not collected by CDS (related double sampling), the noise performance of the final image sensor is poor

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