Image sensor and black level calibration method thereof
First Claim
1. A black level calibration method for an image sensor, the image sensor at least comprising a pixel array, the pixel array comprising a first optical black area, a second optical black area and an active pixel area, the method comprising:
- a) reading first optical black analog information from the first optical black area;
b) determining a black level offset according to the first optical black analog information;
c) reading second optical black analog information from the second optical black area;
d) determining a black level calibration value according to the black level offset and the second optical black analog information;
e) reading active analog information from the active pixel area; and
f) calibrating a black level of the active analog information according to the black level calibration value.
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Abstract
An image sensor including a pixel array, a sampling circuit and a black level calibration circuit is provided. The pixel array includes a first optical black area, a second optical black area and an active pixel area. The sampling circuit respectively reads first optical black information, second optical black information and active pixel information from the first optical black area, the second optical black area and the active pixel area. The black level calibration circuit determines a black level offset according to the first optical black information, and determines a black level calibration value for calibrating the active pixel information.
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Citations
22 Claims
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1. A black level calibration method for an image sensor, the image sensor at least comprising a pixel array, the pixel array comprising a first optical black area, a second optical black area and an active pixel area, the method comprising:
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a) reading first optical black analog information from the first optical black area; b) determining a black level offset according to the first optical black analog information; c) reading second optical black analog information from the second optical black area; d) determining a black level calibration value according to the black level offset and the second optical black analog information; e) reading active analog information from the active pixel area; and f) calibrating a black level of the active analog information according to the black level calibration value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. An image sensor, comprising:
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a pixel array, comprising; a first optical black area; a second optical black area; an active pixel area; a sampling circuit, for reading first optical black analog information from the first optical black area, second optical black analog information from the second optical black area, and active analog information from the active pixel area; and a black level calibration circuit, for determining a black level offset according to the first optical black analog information, and determining a black level calibration value for calibrating a black level of the active analog information according to the black level offset and the second optical black analog information. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22)
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Specification