US5596374A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Television receiver that controls display contrast based on the type of videos being displayed
Assignee: Toshiba Corp
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Filing: 1995-08-28
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Granted: 1997-01-21
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Expires: 2015-08-28
Abstract
Abstract A television receiver includes a first signal processing unit that generates contrast controlled first R, G and B signals and a second signal processing unit that outputs second on-screen R, G and B signals. A switching unit receives the first and second R, G and B signals and selectively outputs one of them to a color CRT. An ABL voltage, which changes in response to a level of video displayed on the CRT, is provided to the first and the second R, G and B signals. A control unit determines whether to execute the contrast control of the second R, G and B signals based on a ratio of video corresponding to the second R, G and B signals out of the total video displayed on the color CRT.
Inventors
- 👤 Hajime Sumiyoshi
- 👤 Takeshi Namikawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 12:54
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/64; H04N9/641; H04N5/00; H04N5/44; H04N5/445; H04N5/44504; H04N21/00; H04N21/40; H04N21/47; H04N21/485; H04N5/57
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
273 words
A television receiver comprising: first signal processing means receiving television signals and generating contrast controlled first R, G and B signals; second signal processing means for generating second on-screen R, G and B signals, the second signal processing means controlling the contrast of the second on-screen R, G and B signals if a contrast control signal is provided to the second signal processing means; switching means receiving the contrast controlled first R, G and B signals and the second R, G and B signals from the first and the second signal processing means, respectively, and selectively outputting one of the first and the second R, G and B signals as an output signal; a color CRT receiving the output signal from the switching means for displaying a video image corresponding to the output signal; means for generating an ABL voltage that changes in response to a level of video displayed on the color CRT, the ABL voltage being provided to the first signal processing means for controlling the contrast of the first R, G and B signals and selectively provided to the second signal processing means as the contrast control signal; and control means for selectively providing the contrast control signal to the second signal processing means for controlling the contrast of the second R, G and B signals such that the contrast control is executed if a ratio of video corresponding to the second R, G and B signals with respect to the total amount of video displayed on the color CRT exceeds a prescribed level and such that the contrast control is prohibited if the ratio is below the prescribed level.
Claim 2
Dependent Claim
273 words
A television receiver comprising: first signal processing means receiving television signals and generating contrast controlled first R, G and B signals; second signal processing means for generating second on-screen R, G and B signals, the second signal processing means controlling the contrast of the second on-screen R, G and B signals if a contrast control signal is provided to the second signal processing means; switching means receiving the contrast controlled first R, G and B signals and the second R, G and B signals from the first and the second signal processing means, respectively, and selectively outputting one of the first and the second R, G and B signals as an output signal; a color CRT receiving the output signal from the switching means for displaying a video image corresponding to the output signal; means for generating an ABL voltage that changes in response to a level of video displayed on the color CRT, the ABL voltage being provided to the first signal processing means for controlling the contrast of the first R, G and B signals and selectively provided to the second signal processing means as the contrast control signal; and control means for selectively providing the contrast control signal to the second signal processing means for controlling the contrast of the second R, G and B signals such that the contrast control is executed if a ratio of video corresponding to the second R, G and B signals with respect to the total amount of video displayed on the color CRT exceeds a prescribed level and such that the contrast control is prohibited if the ratio is below the prescribed level.
Claim 3
Dependent Claim
86 words
A television receiver as claimed in claim 1, wherein the control means includes a judging means for judging whether the second set of R, G and B signals have been selected by the switching means so that a whole area of the color CRT during one vertical scanning period displays only the second set of R, G and B signals and for executing the contrast control of the second set of R, G and B signals based on the result this judgment by the judging means.
Claim 4
Dependent Claim
204 words
A television receiver comprising: a color signal generating unit adapted to receive television signals and to generate contrast controlled first R, G and B signals therefrom; an on-screen display signal generator providing second R, G and B signals; a contrast controller receiving the second R, G and B signals from the on-screen display signal generator; a switching circuit receiving the first and the second R, G and B signals from the color signal generating unit and the contrast controller, respectively, and selectively outputting the received signals as a selected output signal; a color CRT receiving the selected output signal from the switching circuit and displaying a video image corresponding to the selected output signal; an ABL circuit for generating an ABL voltage that changes in response to a level of video displayed on the color CRT; and a control unit that provides a contrast control signal to the contrast controller if a ratio of a video corresponding to the second R, G and B signals with respect to the total amount of video displayed on the color CRT exceeds a prescribed level and that prohibits the contrast control of the second R, G and B signals if the ratio is below the prescribed level.
Claim 5
Dependent Claim
204 words
A television receiver comprising: a color signal generating unit adapted to receive television signals and to generate contrast controlled first R, G and B signals therefrom; an on-screen display signal generator providing second R, G and B signals; a contrast controller receiving the second R, G and B signals from the on-screen display signal generator; a switching circuit receiving the first and the second R, G and B signals from the color signal generating unit and the contrast controller, respectively, and selectively outputting the received signals as a selected output signal; a color CRT receiving the selected output signal from the switching circuit and displaying a video image corresponding to the selected output signal; an ABL circuit for generating an ABL voltage that changes in response to a level of video displayed on the color CRT; and a control unit that provides a contrast control signal to the contrast controller if a ratio of a video corresponding to the second R, G and B signals with respect to the total amount of video displayed on the color CRT exceeds a prescribed level and that prohibits the contrast control of the second R, G and B signals if the ratio is below the prescribed level.
Claim 6
Dependent Claim
84 words
A television receiver as claimed in claim 3, wherein the control unit includes a judging circuit for judging whether the second set of R, G and B signals have been selected by the switching circuit such that the whole area of the color CRT during one vertical scanning period displays only the second set of R, G and B signals, the judging circuit executing the contrast control of the second set of R, G and B signals based on the result of this judgment.
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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) | 2000-01-21 | 2000-07-22 | 2001-01-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-01-21 | 2004-07-22 | 2005-01-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-01-21 | 2008-07-22 | 2009-01-21 | $7700.00 | Window Closed / Lapsed |