US3701842A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Color compensating network with range limitation
Assignee: RCA Licensing Corp
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Filing: 1971-01-04
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Granted: 1972-10-31
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Expires: 1991-01-04
Abstract
Abstract Pending U.S. Pat. applications Ser. No. 36,045, filed May 11, 1970, entitled ''''TINT CORRECTION CIRCUITS'''', now U.S. Pat. No. 3,619,487 and Ser. 103,714, filed concurrently herewith, entitled ''''COLOR COMPENSATING NETWORK FOR AN INTEGRATED CIRCUIT TELEVISION RECEIVER'''' describe arrangements for improving flesh tone rendition in a reproduced image through a selective reduction in Q channel signal gain. The present invention utilizes a switch to energize circuitry-as in the disclosures of the above-noted applications-to effect such gain reduction in the presence of spurious phase errors of the color signal burst relative to the color sub-carrier, and additionally connects the switch in a manner to limit the range of saturation and tint control changes at the same time. This compression of possible range is in a direction to reduce the amount of color variation which could otherwise be introduced into the image by a viewer misadjusting such available controls when his receiver is in its flesh tone mode of operation.
Inventors
- 👤 Loren Robert Kirkwood
- 👤 Larry Allen Cochran
- 👤 Robert Dale Altmanshofer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 15:24
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/64; H04N9/643
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
332 words
In a color television receiver of the type having variable saturation and tint controls and providing improvements of flesh tone rendition through a reduction of Q channel signal gain by (a) shifting the phase of the reference oscillator signal applied to a first color demodulator of said receiver by an amount greater than the phase shift imparted to the reference oscillator signal applied to an included second color demodulator and (b) by further selectively attenuating at least the demodulated output signal of said first demodulator when synchronously applied with chrominance signals representative of the flesh tones to be reduced, and wherein said Q channel gain reduction is actuated by a controllably operative switch having a first conditional mode of operation for normal reproduction of color images and a second conditional mode of operation for reproduction of said images with improved flesh tone rendition, the improvement comprising: means responsive to the placement of said switch in its second conditional mode of operation for limiting the range over which at least one of said controls will be effective in changing the saturation and tint characteristics of the flesh tone improved reproDuced image, said means comprising: first and second impedances; first, second and third terminals; first means responsive to the placement of said switch in its second conditional mode of operation for intercoupling said first impedance with the control whose range of effectiveness on the reproduced image is to be selectively limited, and in series connection with said control between said first and second terminals; and second means similarly responsive to the placement of said switch in its second conditional mode of operation for intercoupling said second impedance with said selected control, and between said second and third terminals; such that when said switch is placed in its first conditional mode of operation for removing the limitation on the range over which said selected control is to be effected, said first and second terminals are interconnected substantially only by said control and a short-circuited impedance.
Claim 2
Dependent Claim
332 words
In a color television receiver of the type having variable saturation and tint controls and providing improvements of flesh tone rendition through a reduction of Q channel signal gain by (a) shifting the phase of the reference oscillator signal applied to a first color demodulator of said receiver by an amount greater than the phase shift imparted to the reference oscillator signal applied to an included second color demodulator and (b) by further selectively attenuating at least the demodulated output signal of said first demodulator when synchronously applied with chrominance signals representative of the flesh tones to be reduced, and wherein said Q channel gain reduction is actuated by a controllably operative switch having a first conditional mode of operation for normal reproduction of color images and a second conditional mode of operation for reproduction of said images with improved flesh tone rendition, the improvement comprising: means responsive to the placement of said switch in its second conditional mode of operation for limiting the range over which at least one of said controls will be effective in changing the saturation and tint characteristics of the flesh tone improved reproDuced image, said means comprising: first and second impedances; first, second and third terminals; first means responsive to the placement of said switch in its second conditional mode of operation for intercoupling said first impedance with the control whose range of effectiveness on the reproduced image is to be selectively limited, and in series connection with said control between said first and second terminals; and second means similarly responsive to the placement of said switch in its second conditional mode of operation for intercoupling said second impedance with said selected control, and between said second and third terminals; such that when said switch is placed in its first conditional mode of operation for removing the limitation on the range over which said selected control is to be effected, said first and second terminals are interconnected substantially only by said control and a short-circuited impedance.
Claim 3
Dependent Claim
27 words
The improvement of claim 1 wherein the placement of said switch in its first conditional mode of operation short-circuits said first impedance and open-circuits said second impedance.
Claim 4
Dependent Claim
25 words
The improvement of claim 1 wherein the placement of said switch in its first conditional mode of operation short-circuits said first and said second impedances.
Claim 5
Dependent Claim
28 words
The improvement of claim 2 wherein the placement of said switch in its second conditional mode of operation connects said second impedance in parallel across said selected control.
Claim 6
Dependent Claim
34 words
The improvement of claim 3 wherein the placement of said switch in its second conditional mode of operation inserts said second impedance in further series connection with said first impedance and said selected control.
Claim 7
Dependent Claim
37 words
The improvement of claim 4 wherein said first terminal is coupled to utilization means within said Q channel to effect said desired change of at least one of said saturation and tint characteristics of the reproduced image.
Claim 8
Dependent Claim
41 words
The improvement of claim 5 wherein a variable arm on said selected control is coupled to utilization means within said Q channel to effect said desired change of at least one of said saturation and tint characteristics of the reproduced image.
Claim 9
Dependent Claim
27 words
The improvement of claim 6 wherein said second impedance comprises a resistor having an impedance value substantially less than the available maximum impedance of said selected control.
Claim 10
Dependent Claim
28 words
The improvement of claim 8 wherein said first impedance also comprises a resistor having an impedance value substantially less than the available maximum impedance of said selected control.
References Cited (Backward Citations)
US3595988A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-31 | 1976-05-01 | 1976-10-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-31 | 1980-05-01 | 1980-10-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-31 | 1984-05-01 | 1984-10-31 | $7700.00 | Window Closed / Lapsed |