Invention Grant
US08179455B2 Optical black-level cancellation for optical sensors using open-loop sample calibration amplifier
有权
使用开环采样校准放大器的光学传感器的光学黑电平消除
- Patent Title: Optical black-level cancellation for optical sensors using open-loop sample calibration amplifier
- Patent Title (中): 使用开环采样校准放大器的光学传感器的光学黑电平消除
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Application No.: US12722148Application Date: 2010-03-11
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Publication No.: US08179455B2Publication Date: 2012-05-15
- Inventor: Lap Chi (David) Leung , Yat Tung Lai , Chun Fai Wong , Kam Hung Chan , Kwok Kuen (David) Kwong
- Applicant: Lap Chi (David) Leung , Yat Tung Lai , Chun Fai Wong , Kam Hung Chan , Kwok Kuen (David) Kwong
- Applicant Address: HK Hong Kong
- Assignee: Hong Kong Applied Science and Technology Research Institute Co., Ltd.
- Current Assignee: Hong Kong Applied Science and Technology Research Institute Co., Ltd.
- Current Assignee Address: HK Hong Kong
- Agency: g Patent LLC
- Agent Stuart T. Auvinen
- Main IPC: H04N5/217
- IPC: H04N5/217

Abstract:
A Optical Black Pixel (OBP) cancellation circuit corrects offsets in sensors in a CCD/CMOS image sensor when reading dark pixels such at the periphery. A pixel voltage is switched to a sampling capacitor during two phases of the same pixel pulse. Sampling capacitors and feedback capacitors connect to differential inputs of an amplifier. An accumulating capacitor accumulates voltage differences and generates a common-mode voltage that is fed back to another sampling capacitor that stores an amplifier offset. The sampling capacitor and accumulating capacitor and their associated switches form a discrete-time first-order low-pass filter that filters the pixel voltage during the first phase. In the second phase the amplifier acts as a unity-gain amplifier to output an average of the pixel voltage differences generated during an OBP time when blackened or covered pixels are read from the image sensor.
Public/Granted literature
- US20110221938A1 Optical Black-Level Cancellation for Optical Sensors Using Open-Loop Sample Calibration Amplifier Public/Granted day:2011-09-15
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