Method and circuit for eliminating sunspots of image sensor, and image sensor

An image sensor and sunspot technology, applied in image communication, television, electrical components, etc., can solve problems such as black spots that cannot be satisfied, achieve image quality assurance, and improve accuracy and efficiency.

CN112261325AActive Publication Date: 2021-01-22CHENGDU LIGHT COLLECTOR TECH
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2021-01-22

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Abstract

The invention discloses a sunspot elimination method and circuit of an image sensor, and the image sensor, and the method comprises the steps: firstly judging whether a sunspot phenomenon happens to acorresponding pixel or not, and locking all sunspots of a counter at a high level through a latch circuit if the sunspot phenomenon happens, so as to enable the corresponding pixel to be displayed asa bright spot. Based on this, the rated count value of the counter can be locked to be a full amplitude when the sunspot phenomenon occurs, and it is guaranteed that the occurring black spots can becompletely eliminated when the sunspot phenomenon occurs. And moreover, sunspots appearing under the irradiation of light intensity with different illuminance can be completely eliminated, so that theimage quality is ensured, and gray spots are avoided.
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Description

technical field

[0001] The invention relates to the application field of integrated circuit technology, in particular to a method and circuit for eliminating sunspots of an image sensor, and an image sensor. Background technique

[0002] The sunspot phenomenon means that under strong light, the photodiode of the pixel unit in the CIS (CMOS image sensor) will generate redundant photoelectrons, and these photoelectrons will cause the reset potential of the pixel unit to decrease sharply, resulting in subsequent analog-to-digital conversion circuits (ADC, Analog to Digital Converter) the actual value of the pixel output value converted by the conversion is too small, and abnormal black spots will appear on the CIS image. In order to avoid the sunspot phenomenon, the existing technology will add a pixel output clamping circuit in the CIS design. During the reset potential readout stage, the clamping circuit can keep the pixel output at a not too low potential to ensure the modul...

Examples

Embodiment Construction

[0048] The specific implementation manner of the present invention will be described in more detail below with reference to schematic diagrams. The advantages and features of the present invention will be more apparent from the following description. It should be noted that all the drawings are in a very simplified form and use imprecise scales, and are only used to facilitate and clearly assist the purpose of illustrating the embodiments of the present invention.

[0049] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right" etc. is based on the orientation or positional relationship shown in the drawings , is only for the convenience of describing the present invention and simplifying the description, but does not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orien...