Image sensor ADC and CDS per column

专利名称：Image sensor ADC and CDS per column发明人：Jeffrey J. Zarnowski,Ketan V. Karia,Thomas

Poonnen

申请号：US11230385申请日：20050920公开号：US07518646B2公开日：20090414

专利附图：

摘要：A solid state imager converts analog pixel values to digital form on an arrayedper-column basis. An N-bit counter supplies an N-bit DAC to produce an analog rampoutput with a level that varies corresponding to the contents of the counter. A ripple

counter or equivalent is associated with each respective column. A clock supplies clocksignals to the counter elements. A comparator in each column gates the counter elementwhen the analog ramp equals the pixel value for that column. The contents of thecounters are transferred sequentially to a video output bus to produce the digital videosignal. Additional black-level readout counter elements can create and store a digitalvalue that corresponds to a dark or black video level. A subtraction element subtractsthe black level value from the pixel value to reduce fixed pattern noise. An additionalarray of buffer counter/latches can be employed. The ripple counters can be configuredas counters to capture the digital video level, and then as shift registers to clock out thevideo levels to an output bus. The clock pulses for the DAC counter and for the ripplecounters can be at the same or different rates.

申请人：Jeffrey J. Zarnowski,Ketan V. Karia,Thomas Poonnen

地址：McGraw NY US,Cortland NY US,Cortland NY US

国籍：US,US,US

代理人：Bernhard P. Molldrem, Jr.

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