Terrance O Smith, 582555 Foothill Blvd UNIT 104, Oakland, CA 94601

4695873, Sep 22, 1987

Jun 10, 1986

6/872568

Terrance Smith - Redwood City CA

Ampex Corporation - Redwood City CA

H04N 944

358 13

Information related to the beginning of data and the phase of color burst on consecutive horizontal scan lines of a digital color television signal is encoded into a variable width pulse. A first transition of that pulse has a predetermined phase relationship with the beginning of data on each line. A second transition of the variable width pulse is formed by providing a delayed transition with respect to the first transition in a variable delay circuit. The second transition is delayed by different amounts of delay, each corresponding to a particular predetermined color burst phase on that particular line.

4797730, Jan 10, 1989

Apr 10, 1987

7/037298

Terrance Smith - Redwood City CA

Ampex Corporation - Redwood City CA

H04N 9475

358 19

A composite analog video signal is sampled at precise locations relative to the phase of the unmodulated color subcarrier along each horizontal line of the video signal. This provides a digitized signal with a constant phase relationship relative to the unmodulated subcarrier phase, which relationship may be used to remove sampling clock phase errors. The digitized samples are filtered by a digital bandpass filter to remove DC and second harmonic noise distortion. Two phase error measurements of the actual sampling clock phase are taken by averaging two sets of burst samples at 0. degree. and 180. degree. crossings, respectively, on selected horizontal lines. These phase error measurements are separately stored, and then are updated on selected alternate horizontal lines to cancel sampling nonlinearity errors. The updated signals are differenced to provide a phase error signal indicative of any sampling clock phase errors. The phase error signal is used to correct the phase of the sampling clock which is supplied to the sampling converter.

4860089, Aug 22, 1989

Apr 10, 1987

7/036647

Terrance Smith - Redwood City CA

Ampex Corporation - Redwood City CA

H04N 1702
H04N 945

358 10

Tracking of a standard or non-standard input video signal, such as a NTSC or PAL composite video signal, is provided by supplying the phase difference between a horizontally-related subcarrier signal, and a variable horizontal sync signal, which is indicative of the SCH phase shift in the input video signal. The phase difference is used to generate a corresponding servo voltage, which then is used to steer the bias of a monostable and thus vary accordingly the trailing edge of a pulse generated thereby, to remove the phase difference. Thus the variable horizontal sync signal is made to coincide with the subcarrier signal, which forces the system to track the subcarrier-to-horizontal sync phase of the input video signal.