CCD imager video output defect compensation
AssigneeTexas Instruments Incorporated
InventorsFrank L. Skaggs, Stanley W. Holcomb, Benny R. Baker, deceased, Patricia J. Peterson, heir
Life of this patent
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Abstract
Erroneous data in the video pulse output string of a CCD imager, caused by defective cells in the imager, is detected by comparison with adjacent data in the string and corrected by replacement with adjacent data. CCD video output is delayed by one clock cycle, then compared to the real time video output while both signals are still on the chip. If the delayed pulse is the same or greater magnitude as the real time pulse, that pulse goes on as part of the video output. If the delayed pulse is less than the real time pulse by a defined amount or more, then the real time pulse is replaced in the output by a copy of the following real time data pulse.
Claims6
A system for detecting, in the video output of a CCD imager array, pixel signals which are generated by defective sensors in said array, and for compensating said video output to restore said video output to a state closely approximating the video output from a defect-free imager array, comprising:
- delay circuit means for delaying said video output;
- comparator circuit means for comparing said delayed video to real-time video and for identifying each pixel signal value of said real-time video output as defective if and only if each said pixel value exceeds the preceeding pixel value by more than a predetermined percentage, and
- correction circuit means for inhibiting said defective pixel signals from becoming part of corrected video, and for inserting in place of each defective pixel signal, a pixel signal from an adjacent good sensor.
Dependencies are inferred from the claim text.