US4755875A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Telecine apparatus including an electro-optical image transducer illuminated by a bias light source
Assignee: BAE Systems Electronics Ltd
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Filing: 1986-02-05
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Granted: 1988-07-05
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Expires: 2006-02-05
Abstract
Abstract A telecine apparatus uses a line array electro-optical image transducer which is illuminated with bias light in addition to the projection light passing through the film. The bias light serves to operate the transducer on a linear portion of its characteristic, and the bias light is pulsed on during the integration periods of the transducer so as to give an accurate and reproducible control of the bias value. The transducer itself has a controllable variable integration period.
Inventors
- 👤 Andrew de M. Fremont
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 15:32
CPC Classifications
H; H04; H04N; H04N3/00; H04N3/36
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
90 words
A telecine apparatus comprising a line array electro-optical image transducer having a recurring light integration period, said image transducer receiving light representing images on a cinematographic film; a bias light source for directly illuminating said image transducer, said bias light source being pulsed on for a period within each light integration period for a duration which is less than said light integration period; and means for operating said bias light source in a pulsed manner to control the amount of bias light falling upon said transducer during each integration period.
Claim 2
Dependent Claim
90 words
A telecine apparatus comprising a line array electro-optical image transducer having a recurring light integration period, said image transducer receiving light representing images on a cinematographic film; a bias light source for directly illuminating said image transducer, said bias light source being pulsed on for a period within each light integration period for a duration which is less than said light integration period; and means for operating said bias light source in a pulsed manner to control the amount of bias light falling upon said transducer during each integration period.
Claim 3
Dependent Claim
17 words
An apparatus as claimed in claim 1 and wherein the transducer has a variable light integration period.
Claim 4
Dependent Claim
24 words
An apparatus as claimed in claim 1 wherein the bias light source comprises a light emitting diode device having an elongate light emissive surface.
Claim 5
Dependent Claim
26 words
An apparatus as claimed in claim 1 wherein the illumination from the bias light source is combined with the said light representing images on the film.
References Cited (Backward Citations)
US2579971A
Cited
US3718752A
Cited
US4080624A
Cited
JPS5570186A
Cited
JPS5644273A
Cited
US4359759A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-07-05 | 1992-01-04 | 1992-07-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-07-05 | 1996-01-04 | 1996-07-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-07-05 | 2000-01-04 | 2000-07-05 | $7700.00 | Window Closed / Lapsed |