Patent EP0506316A2 successfully refreshed from Google Patents.
EP0506316A2
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Vectorscope automatic burst positioning
Assignee: Tektronix Inc
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Filing: 1992-03-23
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Granted: —
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Expires: 2012-03-23
Abstract
Abstract Vectorscope automatic burst positioning for properly aligning a vectorscope display uses a microprocessor (22) to control a phase shifter (14) according to the amplitudes of the chrominance components demodulated from an input color video signal during the burst interval. The demodulated chrominance components are sampled and digitized (18), and the digitized values are tested to determine whether they fall within a predetermined window. The microprocessor applies a statistical approach over a range of phase values to compute a final phase control signal value for the phase shifter that properly aligns the vectorscope display. <IMAGE>
Inventors
- 👤 Robert Proebstel
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 23:33
CPC Classifications
H; H04; H04N; H04N17/00; H04N17/02
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
85 words
A method of automatic positioning of a vectorscope (10) display comprising the steps of: determining the amplitudes of chrominance components (R-Y, B-Y) demodulated from an input color video signal during the burst interval of the input color video signal; and adjusting the phase of a regenerated subcarrier signal derived from the burst portion of the input color video signal according to the determined amplitudes of the chrominance components until a burst vector representing the burst portion lies along a designated axis of the vectorscope display.
Claim 2
Dependent Claim
92 words
A method as recited in claim 1 wherein the adjusting step comprises the steps of: building a phase array from the amplitudes of the chrominance components, the phase array representing a graph of the number of times the determined amplitude of one of the chrominance components is within a predetermined range of amplitude values for each of a plurality of phase increment values; and computing from the phase array a final control signal that determines the phase of the regenerated subcarrier signal so that the burst vector lies along the designated axis.
Claim 3
Dependent Claim
84 words
An automatic burst positioning circuit for a vectorscope (10) comprising: means for determining (18) the amplitudes of chrominance components demodulated from an input color video signal during the burst interval of the input color video signal; and means for adjusting (22) the phase of a regenerated subcarrier signal derived from the burst portion of the input color video according to the determined amplitudes of the chrominance components until a burst vector representing the burst portion lies along a designated axis of the vectorscope display.
Claim 4
Dependent Claim
42 words
A circuit as recited in claim 3 wherein the determining means comprises: means for sampling (S1,C) the demodulated chrominance components during the burst interval to obtain the amplitudes; and means for digitizing (20) the amplitudes prior to input to the adjusting means.
Claim 5
Dependent Claim
42 words
A circuit as recited in claim 4 wherein the digitizing means comprises a window comparator (34) for providing an output signal to the adjusting means when the amplitude of one of the chrominance components is within a predetermined range of amplitude values.
Claim 6
Dependent Claim
65 words
A circuit as recited in claim 5 wherein the digitizing means further comprises means (44) for determining the polarity of the amplitude of another of the chrominance components so that the output signal is provided to the adjusting means when the amplitude of the one chrominance component is within the predetermined range and the amplitude of the another chrominance component is of a predetermined polarity.
Claim 7
Dependent Claim
93 words
A circuit as recited in claim 3 wherein the adjusting means comprises: means for building a phase array from the amplitudes of the chrominance components, the phase array representing a graph of the number of times the determined amplitude of one of the chrominance components is within a predetermined range of amplitude values for each of a plurality of phase increment values; and means for computing from the phase array a final control signal that determines the phase of the regenerated subcarrier signal so that the burst vector lies along the designated axis.
References Cited (Backward Citations)
No citation records indexed.
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