US3944727A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Video disc player with movable mirror for directing light beam onto reflective disc
Assignee: Discovision Associates
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Filing: 1974-05-01
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Granted: 1976-03-16
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Expires: 1994-05-01
Abstract
Abstract A video signal play back device derives video signals from a track on a video disc using a light source and an optical path to a lens system which is supported by an air bearing at a predetermined spacing from the surface of the disc. The optical path includes a mirror which is articulated for rotational motion about an axis which shifts the point of impingement of the transmitted light beam upon the disc in the radial direction. The returned beam is directed to a single photosensitive pick-up which, provides input signals to a circuit which generates a "fine" servo control signal to drive the articulated mirror. The air bearing member includes apparatus providing a bias force that varies with the radial displacement of the transducer assembly relative to the disc center.
Inventors
- 👤 James E. Elliott
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:26
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/08; G11B7/081; G11B7/09; G11B7/095; G11B7/0953
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
169 words
In a video disc playback system including a rotatable turntable adapted to carry a video disc, a player element, a turntable and a video disc carried thereby, an improved transducer system comprising: a. optical system means, carried on the player element including an optical path having a first portion between the disc and a radiant energy source, a second portion for applying radiant energy to the disc and for returning radiant energy reflected from the disc and a third portion for applying returned radiant energy to an energy sensitive transducer; b. energy beam steering means in said second path portion for directing a radiant energy beam to a precisely selected location relative to a disc and for directing the reflected portion of the applied radiant energy beam to said third portion; and c. translating means for imparting relative motion between the turntable and the player element at a predetermined rate in the radial direction for transporting said energy beam steering means in the radial direction relative to a disc.
Claim 2
Dependent Claim
169 words
In a video disc playback system including a rotatable turntable adapted to carry a video disc, a player element, a turntable and a video disc carried thereby, an improved transducer system comprising: a. optical system means, carried on the player element including an optical path having a first portion between the disc and a radiant energy source, a second portion for applying radiant energy to the disc and for returning radiant energy reflected from the disc and a third portion for applying returned radiant energy to an energy sensitive transducer; b. energy beam steering means in said second path portion for directing a radiant energy beam to a precisely selected location relative to a disc and for directing the reflected portion of the applied radiant energy beam to said third portion; and c. translating means for imparting relative motion between the turntable and the player element at a predetermined rate in the radial direction for transporting said energy beam steering means in the radial direction relative to a disc.
Claim 3
Dependent Claim
46 words
A transducer system of claim 1 above wherein said energy beam steering means include an articulated mirror for shifting the point of impingement of the energy beam in the radial direction and for transmitting energy reflected from the point of impingement to said third path portion.
Claim 4
Dependent Claim
77 words
The transducer system of claim 2 above wherein said energy beam steering means include a fixed mirror in proximity to said articulated mirror for increasing the optical path and for providing more than one reflection from said articulated mirror in the paths of the applied energy beam and the reflected energy beam wherein small increments of motion imparted to said articulated mirror result in substantially larger excursions of the point of impringement of the applied energy beam.
Claim 5
Dependent Claim
37 words
The transducer system of claim 3, above wherein said fixed and articulated mirrors are positioned to impart multiple reflections to the applied and reflected energy beams, thereby increasing the effective length of said optical path second portion.
Claim 6
Dependent Claim
47 words
The transducer system of claim 1, above further including servo means coupled to said energy beam steering means and to the energy sensitive transducer operable in response to the magnitude of reflected energy to relocate the point of impingement of the applied beam relative to the disc.
References Cited (Backward Citations)
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US3530258A
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US3798386A
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US3715524A
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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) | 1979-03-16 | 1979-09-15 | 1980-03-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-16 | 1983-09-15 | 1984-03-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-16 | 1987-09-15 | 1988-03-16 | $7700.00 | Window Closed / Lapsed |