US3879749A
Expired / Lapsed
US
⏱️ 0.0 years remaining
TV test pattern and method of testing
Assignee: Sencore Inc
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Filing: 1973-08-20
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Granted: 1975-04-22
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Expires: 1993-08-20
Abstract
Abstract A test pattern generator electronically generates a wave form comprising a plurality of equal amplitude, discrete video frequencies at strategic points on the I.F. response curve, which frequencies are in synchronism with the horizontal sync pulses provided in the wave form so that application of the wave form to the receiver produces a plurality of horizontal lines on the screen of the receiver to visually show the alignment and other characteristics thereof.
Inventors
- 👤 Robert E Baum
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 09:42
CPC Classifications
H; H04; H04N; H04N17/00; H04N17/04; H04N17/045
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
95 words
A test pattern generator for use in determining operating characteristics of a color television receiver, means for providing a first signal having a frequency substantially equal to the standard subcarrier frequency, means for providing a plurality of video signals within the I.F. response band of said television receiver, and means for combining said first signal and said video signals to provide a single wave form made up of discrete time displaced bands in which said video signals all have the same amplitude and said first signal has an amplitude twice that of said video signals.
Claim 2
Dependent Claim
95 words
A test pattern generator for use in determining operating characteristics of a color television receiver, means for providing a first signal having a frequency substantially equal to the standard subcarrier frequency, means for providing a plurality of video signals within the I.F. response band of said television receiver, and means for combining said first signal and said video signals to provide a single wave form made up of discrete time displaced bands in which said video signals all have the same amplitude and said first signal has an amplitude twice that of said video signals.
Claim 3
Dependent Claim
95 words
A test pattern generator for use in determining operating characteristics of a color television receiver, means for providing a first signal having a frequency substantially equal to the standard subcarrier frequency, means for providing a plurality of video signals within the I.F. response band of said television receiver, and means for combining said first signal and said video signals to provide a single wave form made up of discrete time displaced bands in which said video signals all have the same amplitude and said first signal has an amplitude twice that of said video signals.
Claim 4
Dependent Claim
95 words
A test pattern generator for use in determining operating characteristics of a color television receiver, means for providing a first signal having a frequency substantially equal to the standard subcarrier frequency, means for providing a plurality of video signals within the I.F. response band of said television receiver, and means for combining said first signal and said video signals to provide a single wave form made up of discrete time displaced bands in which said video signals all have the same amplitude and said first signal has an amplitude twice that of said video signals.
Claim 5
Dependent Claim
25 words
A test pattern generator according to claim 1 wherein said plurality of video signals comprise signals having respective frequencies at 750 KHz and 3.0 MHZ.
Claim 6
Dependent Claim
46 words
A test pattern generator according to claim 1 further comprising means for providing horizontal and vertical synchronizing signals, means for synchronizing said first signal and said video signals with one of said synchronizing signals, and means for combining said synchronizing signals into said single wave form.
Claim 7
Dependent Claim
34 words
A test pattern generator according to claim 3 comprising means for generating another video signal having a sufficiently low video frequency to provide large areas in the displayed pattern for black and white reference.
Claim 8
Dependent Claim
15 words
A test pattern generator according to claim 1 wherein said bands are of equal width.
Claim 9
Dependent Claim
28 words
A test pattern generator according to claim 1 wherein said single waveform includes a band having no video signal to provide in the displayed pattern a gray reference.
Claim 10
Independent Claim
94 words
A method of testing the bandwidth of a color television receiver, comprising the steps of providing a signal made up of a plurality of discrete, time displaced, equal length bands of respectively different video frequencies all having the same amplitude and a discrete band at a frequency of 3.56 MHz having an amplitude twice that of said video frequencies, and applying said signal to said receiver to provide a video output signal, and applying said video output signal to a cathode ray tube to display a plurality of different lines corresponding to said bands.
Claim 11
Independent Claim
94 words
A method of testing the bandwidth of a color television receiver, comprising the steps of providing a signal made up of a plurality of discrete, time displaced, equal length bands of respectively different video frequencies all having the same amplitude and a discrete band at a frequency of 3.56 MHz having an amplitude twice that of said video frequencies, and applying said signal to said receiver to provide a video output signal, and applying said video output signal to a cathode ray tube to display a plurality of different lines corresponding to said bands.
Claim 12
Dependent Claim
24 words
The method according to claim 7 wherein said signal further includes snyc pulses, and said video frequencies are in synchronism with said sync pulses.
Claim 13
Dependent Claim
30 words
The method according to claim 8 wherein said video frequencies are respectively located near the center and the left and right hand upper corners of the standard television I.F. response-curve.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-21 | 1978-10-21 | 1979-04-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-21 | 1982-10-21 | 1983-04-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-21 | 1986-10-21 | 1987-04-22 | $7700.00 | Window Closed / Lapsed |