Patent US3914541A successfully refreshed from Google Patents.
US3914541A
Expired / Lapsed
US
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Video disc player
Assignee: Discovision Associates
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Filing: 1972-12-11
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Granted: 1975-10-21
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Expires: 1992-12-11
Abstract
Abstract A player for video disc includes an improved transducer arm and tracking assembly which is servo controlled from the playback circuits to follow the information track. An articulated mirror provides ''''fine'''' tracking control. When a thin, flexible video disc is used, a rotating turntable provides a fluid cushion bearing to support the disc. A vacuum assisted reading head assembly draws the disc toward the head and maintains an optimum head-to-disc spacing.
Inventors
- 👤 James E Elliott
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 09:53
CPC Classifications
G; G11; G11B; G11B19/00; G11B19/20; G11B19/2009; G11B17/00; G11B17/32; G11B23/00; G11B23/50; G11B23/505; G11B7/00; G11B7/08; G11B7/09; G11B7/0908; G11B7/0925
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
174 words
A player for retrieving information recorded on video discs comprising in combination: disc drive means for imparting rotational velocity to the disc; player arm means coupled to said disc drive means for moving radially with respect to the rotating disc at a rate related to the rotational velocity of the disc; reading beam transmission means coupled to said driven player arm for applying a reading beam from a source to the disc surface and for transmitting to a reading transducer the beam reflected from the disc surface; movable mirror means in the path of said reading beam transmission means for radially translating the point of impingement of the reading beam on the disc surface for accurately determining the exact point of impingement of the beam on the disc surface; said movable mirror means including a piezoelectric beam adapted to flex in a direction orthogonal to said beam axis and having a reflecting surface orthogonally mounted on a free end of said beam whereby flexing of said beam moves said reflecting surface in an arc.
Claim 2
Dependent Claim
174 words
A player for retrieving information recorded on video discs comprising in combination: disc drive means for imparting rotational velocity to the disc; player arm means coupled to said disc drive means for moving radially with respect to the rotating disc at a rate related to the rotational velocity of the disc; reading beam transmission means coupled to said driven player arm for applying a reading beam from a source to the disc surface and for transmitting to a reading transducer the beam reflected from the disc surface; movable mirror means in the path of said reading beam transmission means for radially translating the point of impingement of the reading beam on the disc surface for accurately determining the exact point of impingement of the beam on the disc surface; said movable mirror means including a piezoelectric beam adapted to flex in a direction orthogonal to said beam axis and having a reflecting surface orthogonally mounted on a free end of said beam whereby flexing of said beam moves said reflecting surface in an arc.
Claim 3
Dependent Claim
73 words
The player of claim 1, above, wherein said disc drive means include a fluid cushion turntable for supporting the disc away from the turntable surface; and said reading beam transmission means include a transducer head adapted to create a negative pressure differential in the region between said head and the disc relative to the region between the disc and said turntable for biasing the disc into a predetermined proximity to said transducer head.
Claim 4
Dependent Claim
69 words
The player of claim 2, above, further including a pressure control system coupled to said transducer head and said player arm means for modifying the negative pressure differential as a function of player arm means radial location relative to the disc to maintain a constant head to disc spacing, whereby variations of fluid pressure as a function of circumferential velocity are accommodated by adjustments of the pressure control system.
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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) | 1978-10-20 | 1979-04-21 | 1979-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-20 | 1983-04-21 | 1983-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-20 | 1987-04-21 | 1987-10-21 | $7700.00 | Window Closed / Lapsed |