US4891700A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System for inserting a test signal in a video image scanning line
Assignee: Deutsche Thomson Brandt GmbH
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Filing: 1988-09-22
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Granted: 1990-01-02
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Expires: 2008-09-22
Abstract
Abstract A television receiver includes a source of test signals for controlling parameters such as picture tube cut-off level and drive level. The test signals are inserted individually during visible scanning lines along the upper edge of the display screen, one test signal line per field, only when the brightness of a displayed picture exceeds a given level so as to mask the presence of the test signal. The test signal insertion process is disabled for low picture brightness conditions.
Inventors
- 👤 Thierry Meunier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 07:39
CPC Classifications
H; H04; H04N; H04N17/00; H04N17/04; H04N9/00; H04N9/64; H04N9/645
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
138 words
In a video signal processing system including an image display device for displaying an image in response to an image component of a video signal, apparatus comprising: a video signal path for conveying said image component to said image display device; means for generating a test signal for use in automatically adjusting a system parameter affecting the magnitude of current conducted by said display device; means for selectively inserting said test signal into said video signal path during a scanning line image display interval in an initial visible portion of an image scanning field; and control means coupled to said inserting means for enabling said test signal to be inserted into said video signal path when the brightness of a displayed image exceeds a given level, and for inhibiting the insertion of said test signal at other times.
Claim 2
Dependent Claim
138 words
In a video signal processing system including an image display device for displaying an image in response to an image component of a video signal, apparatus comprising: a video signal path for conveying said image component to said image display device; means for generating a test signal for use in automatically adjusting a system parameter affecting the magnitude of current conducted by said display device; means for selectively inserting said test signal into said video signal path during a scanning line image display interval in an initial visible portion of an image scanning field; and control means coupled to said inserting means for enabling said test signal to be inserted into said video signal path when the brightness of a displayed image exceeds a given level, and for inhibiting the insertion of said test signal at other times.
Claim 3
Dependent Claim
24 words
A system according to claim 1, wherein: said control means includes means responsive to the magnitude of current conducted by said image display device.
Claim 4
Dependent Claim
23 words
A system according to claim 1, wherein: said test signal is inserted in a first visible horizontal scanning line of an image field.
Claim 5
Dependent Claim
16 words
A system according to claim 1, wherein: said test signal is inserted during consecutive image fields.
Claim 6
Dependent Claim
44 words
A system according to claim 1, wherein: said generating means provides plural test signals each respectively to be used for adjusting system parameters affecting the magnitude of said display device current; and said plural test signals are separately inserted during separate consecutive image fields.
Claim 7
Dependent Claim
23 words
A system according to claim 5, wherein: said plural test signals include signals to be used for adjusting cut-off and drive levels, respectively.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-01-01 | 1993-07-03 | 1994-01-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-01-01 | 1997-07-03 | 1998-01-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-01-01 | 2001-07-03 | 2002-01-02 | $7700.00 | Window Closed / Lapsed |