US3573352A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Color tone adjustment for color tv receiver
Assignee: Panasonic Holdings Corp
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Filing: 1968-04-08
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Granted: 1971-04-06
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Expires: 1988-04-08
Abstract
Abstract This specification discloses a color television receiver wherein the white balance controlling reference color illumination occurring in a portion of the fluorescent screen is passed through three primary-color filters so as to be separated into ''''red,'''' ''''green'''' and ''''blue'''' light rays which are irradiated onto photosensitive elements so that variations in the filtered light rays are converted to electrical quantities to be fed back to the video circuit, thereby directly or indirectly controlling the color reproduction signal voltage to be applied to the color picture tube.
Inventors
- 👤 Yasuhiro Fujita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 21:32
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/64; H04N9/73
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
120 words
A color television receiver comprising a color picture tube with a phosphor screen, a television signal receiving circuitry having a video circuit means, a primary color filter means and a photosensitive means optically associated with said filter means, wherein said video circuit means includes means for producing a white balance controlling reference light emission on a part of said phosphor screen in a timed relation with a scanning signal associated with said television signal, said reference light emission being representative of the state of the color tone of a color image being viewed and being directed through said filter means to said photosensitive means, and means for feeding the output of said photosensitive means back to said video circuit means.
Claim 2
Dependent Claim
120 words
A color television receiver comprising a color picture tube with a phosphor screen, a television signal receiving circuitry having a video circuit means, a primary color filter means and a photosensitive means optically associated with said filter means, wherein said video circuit means includes means for producing a white balance controlling reference light emission on a part of said phosphor screen in a timed relation with a scanning signal associated with said television signal, said reference light emission being representative of the state of the color tone of a color image being viewed and being directed through said filter means to said photosensitive means, and means for feeding the output of said photosensitive means back to said video circuit means.
Claim 3
Dependent Claim
17 words
A color television receiver according to claim 1, wherein said photosensitive means is formed by photosensitive resistors.
Claim 4
Dependent Claim
21 words
A color television receiver according to claim 1, wherein said photosensitive means is formed by photosensitive means if formed by phototransistors.
Claim 5
Dependent Claim
16 words
A color television receiver according to claim 1, wherein said photosensitive means if formed by photodiodes.
Claim 6
Dependent Claim
27 words
A color television receiver according to claim 1, wherein said photosensitive means constitutes means for controlling the amplification factor of video amplifier means in said video circuit.
Claim 7
Dependent Claim
42 words
A color television receiver according to claim 1, wherein said photosensitive means comprises means for controlling the bias for video amplifier means in said video circuit, which amplifier means is DC coupled to the cathode or grids of said color picture tube.
Claim 8
Dependent Claim
39 words
A color television receiver according to claim 1, wherein said photosensitive means is formed by photosensitive resistors which are connected with the grids or cathodes of the color picture tube so as to serve as bias voltage divider resistors.
Claim 9
Dependent Claim
47 words
A color television receiver according to claim 1, wherein said white balance controlling reference light emission producing means includes clamping circuit means for respectively clamping red-, green- and blue-color difference signals and a luminance signal to a predetermined DC level simultaneously for the same period of time.
Claim 10
Dependent Claim
27 words
A color television receiver according to claim 8, wherein said predetermined DC level producing means causes a white color emission on said part of said phosphor screen.
Claim 11
Dependent Claim
54 words
A color television receiver according to claim 1, wherein said white balance controlling reference light emission producing means includes means for periodically varying the amplitude of a signal corresponding to said reference light emission such that a uniform white balance control is attained in the range from the black level to the white level.
Claim 12
Dependent Claim
45 words
A color television receiver according to claim 1, further comprising means for actuating said white balance controlling reference light emission producing means, wherein said actuating means includes circuit means responsive to a vertical or horizontal flyback pulse signal or a vertical or horizontal sync signal.
References Cited (Backward Citations)
US2931856A
Cited
US3479448A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-04-05 | 1974-10-05 | 1975-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-05 | 1978-10-05 | 1979-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-05 | 1982-10-05 | 1983-04-06 | $7700.00 | Window Closed / Lapsed |