Television – Basic receiver with additional function – Multimode
Reexamination Certificate
2011-08-09
2011-08-09
Harold, Jefferey (Department: 2422)
Television
Basic receiver with additional function
Multimode
C348S572000, C348S537000, C348S520000, C341S155000, C341S172000
Reexamination Certificate
active
07995144
ABSTRACT:
A digital video system (2) is disclosed, in which an analog input video signal is sampled at an optimum sample phase (Pnc), and converted to a digital datastream for display. A phase-locked loop (12) generates a plurality of sample clock phases. One of the sample clock phases (Pnc) is applied to an analog-to-digital converter (10), which digitizes the analog input video signal accordingly. Phase alignment circuitry (20) is provided that includes three sample-and-hold circuits (22b,22c,22a) that sample the analog input video signal, in parallel with the analog-to-digital converter (10), at times before, at, and after the current sample clock phase used by the analog-to-digital converter (10). The earlier and later sampled voltages are compared against the current sampled voltages to generate difference voltages that are each compared against a threshold voltage (Vthr). The numbers of times that the difference voltages exceed the threshold voltage over a field or frame is analyzed according to various techniques, to determine whether and in which direction to adjust the position of the current sample clock phase within the pixel period.
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Clynes Steven D.
Xiu Liming
Brady III Wade J.
Harold Jefferey
Patti John J.
Sugrim Chandraika
Telecky Jr Frederick J.
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