Television – Image signal processing circuitry specific to television – A/d converters
Reexamination Certificate
2007-06-19
2007-06-19
Yenke, Brian P. (Department: 2622)
Television
Image signal processing circuitry specific to television
A/d converters
C348S673000, C348S677000, C348S689000, C348S691000
Reexamination Certificate
active
10931877
ABSTRACT:
Digital dc restore methods and apparatus to restore the DC component of an analog waveform to a quantized reference value level at a given temporal point on a waveform, prior to an ADC. This may used to establish the relationship between the full scale digital value out of the ADC and the waveform being digitized. For a video signal, the Digital Value of Black, is compared with the value on the back porch of the video signal. The difference is converted to the analog domain by a DAC clocked at the Temporal Point to provide a sample and hold function. An amplifier compares the difference, mapped to one half full scale digital, to an analog common mode voltage for the ADC, removing any error due to the difference between them. Other applications include correlated double sampling of contact image sensors to remove Dark Current Offset.
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Blakely , Sokoloff, Taylor & Zafman LLP
Maxim Integrated Products Inc.
Yenke Brian P.
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