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US4816897A Expired / Lapsed US ⏱️ 0.0 years remaining

Chrominance to luminance delay and gain measurement display

Assignee: Tektronix Japan Corp
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Filing: 1988-01-11
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Granted: 1989-03-28
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Expires: 2008-01-11
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Abstract

Abstract A chrominance to luminance gain and delay measurement display shows gain and delay inequalities due to differences between luminance and chrominance chanels of a video device as a point within a rectangular coordinate display system with respect to established tolerance limits. An appropriate test signal having bar and modulated pulse waveforms is selected from digitized video data stored in a field store acquisition memory. Luminance and chrominance arrays are derived from the modulated pulse waveform. The center points for each array are identified and displayed as a time difference between the center points along one axis of the display and as an amplitude ratio (chrominance/luminance) between the center points along an orthogonal axis of the display. The display includes a tolerance window so that an operator can readily observe whether the chrominance to luminance gain and delay is within established tolerances.

Inventors

  • 👤 Tomoo Konishi

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 21:57
CPC Classifications
H; H04; H04N; H04N17/00; H04N17/02

Claims Analysis

Total Claims: 3
Claim 1
Independent Claim 127 words
A method for displaying chrominance to luminance gain and delay values comprising the steps of: selecting a desired portion of digitized video data containing a specified test signal from an acquisition memory containing a field of the digitized video data for processing; locating a specific waveform within the specified test signal; building a luminance array and a chrominance array from the digitized video data representing the specific waveform; computing from the luminance and chrominance arrays said chrominance to luminance gain and delay values; and displaying the computed chrominance to luminance gain and said delay values on a graphic display having rectangular coordinates, one coordinate representing a percentage ratio of said chrominance to luminance gain and the other coordinate representing a time for the chrominance to luminance delay.
Claim 2
Independent Claim 127 words
A method for displaying chrominance to luminance gain and delay values comprising the steps of: selecting a desired portion of digitized video data containing a specified test signal from an acquisition memory containing a field of the digitized video data for processing; locating a specific waveform within the specified test signal; building a luminance array and a chrominance array from the digitized video data representing the specific waveform; computing from the luminance and chrominance arrays said chrominance to luminance gain and delay values; and displaying the computed chrominance to luminance gain and said delay values on a graphic display having rectangular coordinates, one coordinate representing a percentage ratio of said chrominance to luminance gain and the other coordinate representing a time for the chrominance to luminance delay.
Claim 3
Dependent Claim 98 words
A method as recited in claim 1 wherein the displaying step comprises the steps of: graphically displaying a rectangular coordinate system on a display screen having time representing chrominance to luminance delay along one axis and percentage representing said chrominance to luminance gain along the other axis; graphically displaying within the rectangular coordinate system a tolerance box representing acceptable chrominance to luminance delay and gain values with respect to nominal values; and displaying the computed chrominance to luminance delay and gain values as a crosshair within the rectangular coordinate system and as numerical values on the display screen.

References Cited (Backward Citations)

US4635094A Cited
US4740841A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1992-03-27 1992-09-26 1993-03-28 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1996-03-27 1996-09-26 1997-03-28 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2000-03-27 2000-09-26 2001-03-28 $7700.00 Window Closed / Lapsed

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