US4774580A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Video signal control apparatus
Assignee: Toshiba Corp
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Filing: 1987-10-21
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Granted: 1988-09-27
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Expires: 2007-10-21
Abstract
Abstract A video signal control apparatus disclosed herewith stores, in a memory, contrast control data that is output from a video operation unit, reads out the control data from the memory during a vertical retrace period in which no image is output, and performs contrast control within the vertical retrace period based on the control data.
Inventors
- 👤 Yoji Miyasako
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 05:51
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/14; H04N5/44; H04N5/57
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
103 words
A video signal control apparatus for controlling a status of a video image by varying DC and AC components of a video signal, said apparatus comprising: a video operation unit; control data storage means for storing control data of an AC component of a video signal produced from said video operation unit; data readout means for reading out said control data from said control data storage means during a vertical retrace period in which no image is output; and AC component control means for varying said AC component of said video signal based on said control data read by said data readout means
Claim 2
Dependent Claim
103 words
A video signal control apparatus for controlling a status of a video image by varying DC and AC components of a video signal, said apparatus comprising: a video operation unit; control data storage means for storing control data of an AC component of a video signal produced from said video operation unit; data readout means for reading out said control data from said control data storage means during a vertical retrace period in which no image is output; and AC component control means for varying said AC component of said video signal based on said control data read by said data readout means
Claim 3
Dependent Claim
25 words
The video signal control apparatus according to claim 1, wherein said control data of said AC component of said video signal is contrast control data.
Claim 4
Dependent Claim
19 words
The video signal control apparatus according to claim 1, wherein said control data storage means includes a buffer memory.
Claim 5
Dependent Claim
35 words
The video signal control apparatus according to claim 1, wherein said data readout means includes a switch which is turned on during said vertical retrace period and is turned off during a vertical scanning period.
Claim 6
Dependent Claim
42 words
The video signal control apparatus according to claim 4, wherein said apparatus further comprises a vertical scanning circuit for producing a control signal and a switching operation of said switch is controlled by said control signal produced in said vertical scanning circuit.
Claim 7
Dependent Claim
44 words
The video signal control apparatus according to claim 5, wherein said vertical scanning circuit comprises an oscillator, a saw-tooth wave generator, a vertical amplifier and a vertical output circuit, and an output of said oscillator is used as said control signal for said switch.
Claim 8
Dependent Claim
46 words
The video signal control apparatus according to claim 5, wherein said vertical scanning circuit comprises a frequency divider, a saw-tooth wave generator, a vertical amplifier and a vertical output circuit, and an output of said frequency divider is used as said control signal for said switch.
Claim 9
Dependent Claim
42 words
The video signal control apparatus according to claim 4, wherein said apparatus further comprises a sync signal separator for separating a vertical sync signal from said video signal and a switching operation of said switch is controlled by said vertical sync signal.
Claim 10
Dependent Claim
19 words
The video signal control apparatus according to claim 1, wherein said AC component control means includes a contrast controller.
Claim 11
Dependent Claim
46 words
The video signal control apparatus according to claim 1, wherein said AC component control means includes a register, a digital-to-analog converter for performing a digital-to-analog conversion of data latched in said register and a contrast controller which is supplied with an output of said digital-to-analog converter.
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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) | 1991-09-27 | 1992-03-28 | 1992-09-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-09-27 | 1996-03-28 | 1996-09-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-09-27 | 2000-03-28 | 2000-09-27 | $7700.00 | Window Closed / Lapsed |