Differential image sensor with external writable digital pixel storage

Abstract

The invention belongs to the technical field of image sensors, and particularly relates to a differential image sensor with external writable digital pixel storage, which comprises a pixel array and a plurality of acquisition circuits, each acquisition circuit comprises at least one sensor circuit for generating a sensor signal VSIG according to a light signal illuminating at least one pixel corresponding to the light sensor; at least one analog-to-digital conversion circuit which is used for generating a current digital signal according to the sensor signal VSIG; at least one digital storage circuit for storing a previous digital signal; at least one digital comparison circuit which is used for comparing the level of the current digital signal with the level of the previous digital signal and judging whether the current digital signal has a changed level or not; and at least one digital output circuit which is used for generating and outputting an event signal when the current digital signal has a changing level.

Description

technical field [0001] The invention belongs to the technical field of image sensors, in particular to a differential image sensor with external writable digital pixel storage. Background technique [0002] Image sensors with one ADC per pixel or per small subset of pixels are well known in the art, and these are typically used in applications where significant processing is done in the pixel, such as X-ray particle trajectory tracking or satellite imaging. [0003] In addition, image sensors that generate events using image pixel-level change detection, storage and comparison in the analog domain are well known. The comparison and storage in the analog domain provide advantages and disadvantages over digital methods. The advantage is that it can be based on a compact structure However, the disadvantage is gradual memory degradation, including "hot pixels", sensitivity to mismatch, and reduced flexibility of optical-to-electrical conversion functions. [0004] Image sensors...

AI Technical Summary

Problems solved by technology

[0003] In addition, image sensors that generate events using image pixel-level change detection, storage and comparison in the analog domain are well known. The comparison and storage in the analog domain provide advantages and disadvantages over digital methods. The advantage is that it can be based on a compact structure The disadvantage is gradual memory degradation, including "hot pixels", sensitivity to mismatch, reduced flexibility of optical-to-electrical conversion functions, etc.

Images