Patent US4009489A successfully refreshed from Google Patents.
US4009489A
Expired / Lapsed
US
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Negative color film mask correction
Assignee: RCA Corp
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Filing: 1976-02-26
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Granted: 1977-02-22
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Expires: 1996-02-26
Abstract
Abstract Negative color film is processed in a color telecine camera by the selection of an optical filter which provides equal light transmission for the red and green colors so as to produce equal red and green video signals. The electrical gain of the blue channel is then increased to produce a blue video signal equal to the red and green video signals.
Inventors
- 👤 Harold George Seer, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:46
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/11
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
84 words
Apparatus for processing negative color film in a telecine camera which develops red, green and blue color video signals, said negative film having unequal light transmission for red, green and blue light components, comprising: optical filter means for equalizing said red and green light transmission of said film for developing equal red and green video signals from said camera; and gain adjustment means for increasing the blue color video signal for developing a blue video signal equal to said red and green video signals.
Claim 2
Dependent Claim
84 words
Apparatus for processing negative color film in a telecine camera which develops red, green and blue color video signals, said negative film having unequal light transmission for red, green and blue light components, comprising: optical filter means for equalizing said red and green light transmission of said film for developing equal red and green video signals from said camera; and gain adjustment means for increasing the blue color video signal for developing a blue video signal equal to said red and green video signals.
Claim 3
Dependent Claim
32 words
In a telecine camera according to claim 1 wherein the light transmission of said negative film is greatest for red light components and minimum for blue light components of said light source.
Claim 4
Dependent Claim
107 words
In a telecine camera having a light source, a film transport, and a color camera in a common light path for developing equal red, green and blue color video signals from negative color film having unequal light transmission for red, green and blue light components, comprising: optical filter means located in said light path for equalizing red and green light transmission from said film for developing equal red and green video signals from said camera; and gain adjustment means coupled to said camera for increasing the blue color video signal for developing a blue color signal equal to said red and green video signal from said camera.
Claim 5
Dependent Claim
107 words
In a telecine camera having a light source, a film transport, and a color camera in a common light path for developing equal red, green and blue color video signals from negative color film having unequal light transmission for red, green and blue light components, comprising: optical filter means located in said light path for equalizing red and green light transmission from said film for developing equal red and green video signals from said camera; and gain adjustment means coupled to said camera for increasing the blue color video signal for developing a blue color signal equal to said red and green video signal from said camera.
Claim 6
Dependent Claim
32 words
In a telecine camera according to claim 3 wherein the light transmission of said negative film is greatest for red light components and minimum for blue light components of said light source.
Claim 7
Dependent Claim
37 words
In a telecine camera according to claim 4 wherein said common light path further includes a variable neutral density disk for increasing the filtered red, green and blue light components to a 100% value after said filter.
References Cited (Backward Citations)
US3005042A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-02-22 | 1980-08-23 | 1981-02-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-02-22 | 1984-08-23 | 1985-02-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-02-22 | 1988-08-23 | 1989-02-22 | $7700.00 | Window Closed / Lapsed |