发明名称 |
DIGITAL CORRELATED DOUBLE SAMPLE CAMERA |
摘要 |
A digital electronic camera, method and circuit for converting an analog image-bearing signal from an electronic imaging device. The image-bearing signal provides both a pixel-reference signal and a pixel-image signal for each one of a plurality of pixels of the imaging device. The circuit includes a voltage clamp that adjusts a level of the image-bearing signal based on a black reference level to produce a clamped image-bearing signal. An analog-to-digital converter (ADC) is coupled to digitize the clamped image-bearing signal and operated to produce a first digital value representative of the pixel-reference signal for a pixel, and operated to produce a second digital value representative of the pixel-image signal. Then, a first digital subtractor generates a first digital difference signal based on the first and second digital values to reduce pixel-to-pixel noise and/or drift. The circuit optionally includes a feedback circuit that adjusts the black-reference level based on a comparison between the digital reference value and a digital black-reference value selected to be near or at one end of a range of values accommodated by the ADC. The circuit further optionally includes a clock-adjustment circuit that adjusts an image-voltage-signal sampling clock and/or a reference-voltage-signal sampling clock to sample the respective signal at substantially an end of a valid sampling interval. The circuit further optionally includes an accumulator/averager which is operated to accumulate and average one or more digital values of non-imaging pixels to produce a third digital value, and a second digital subtractor is operated to generate a second digital difference signal based on the first on the first digital difference signal and the third digital value, to reduce row-to-row noise and/or drift. A dovetail camera mounting system is also disclosed.
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申请公布号 |
WO9907138(A1) |
申请公布日期 |
1999.02.11 |
申请号 |
WO1998US15848 |
申请日期 |
1998.07.30 |
申请人 |
PPT VISION, INC. |
发明人 |
TONKIN, STEVEN, W.;LIEBERT, SCOTT, S. |
分类号 |
H04N5/18;H04N5/217;H04N5/225;H04N5/335;H04N5/357;H04N5/361;H04N5/378;(IPC1-7):H04N5/217 |
主分类号 |
H04N5/18 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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