US4381556A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Videodisc reader with longitudinally displaced turntable
Assignee: Thales SA
•
Filing: 1980-12-03
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Granted: 1983-04-26
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Expires: 2000-12-03
Abstract
Abstract There is disclosed a device for displacing a video disk with respect to a reading head which includes the driving of a conductive disk by means of a video disk rotational motor. The conductive disk passes through the air gaps of two electromagnets located on either side of the displacement axis of a movable member supporting the rotational motor. By differentially energizing the electromagnets, a force is produced which provides for forward and backward movement of the complete movable member of the reader.
Inventors
- 👤 Guy Bourdon
- 👤 Jean-Claude Lehureau
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 08:38
CPC Classifications
G; G11; G11B; G11B17/00; G11B17/34; G11B19/00; G11B19/20; G11B19/24; G11B7/00; G11B7/08
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
123 words
A device for providing a rectilinear displacement, with respect to a fixed support, of a rotary engine having a shaft, said displacement being in a direction perpendicular to the axis of rotation of said shaft, said device comprising: a movable carriage rigidly locked with said engine; means to guide said carriage along said perpendicular direction; magnetic means producing a first air gap provided on said support and producing a magnetic output across of said first air gap; a conductive disk fixed on said shaft and crossing said air gap wherein the magnetic output of said magnetic means produces said displacement; and electronic control means for controlling the magnetic output of said magnetic means in order to control said displacement of said rotary engine.
Claim 2
Independent Claim
123 words
A device for providing a rectilinear displacement, with respect to a fixed support, of a rotary engine having a shaft, said displacement being in a direction perpendicular to the axis of rotation of said shaft, said device comprising: a movable carriage rigidly locked with said engine; means to guide said carriage along said perpendicular direction; magnetic means producing a first air gap provided on said support and producing a magnetic output across of said first air gap; a conductive disk fixed on said shaft and crossing said air gap wherein the magnetic output of said magnetic means produces said displacement; and electronic control means for controlling the magnetic output of said magnetic means in order to control said displacement of said rotary engine.
Claim 3
Dependent Claim
65 words
A device according to claim 1, wherein said magnetic means further comprises a means for producing a second air gap enclosing part of said conductive disk which second air gap is positioned on the side of said disk opposite said first air gap and wherein a line connecting the centers of said first and second air gap is perpendicular to the direction of said displacement.
Claim 4
Dependent Claim
41 words
A device according to claim 2 wherein said electronic control means outputs a signal to differentially energize the output of said magnetic means for providing said displacement in one of two directions perpendicular to the axis of rotation of said shaft.
Claim 5
Dependent Claim
42 words
A device according to claim 3 wherein said electronic control means provides an output by controlling the magnetic output of said magnetic means in order to maintain a constant rotation speed of said motor by breaking said motor via said conductive disk.
Claim 6
Dependent Claim
74 words
A video disk reader comprising: a device according to any one of claims 1-4; means for affixing the video disk to the rotational motor shaft; a reading head for supplying tracking and rotational speed error signals; and means for feeding said error signals to said electonic control means so that said displacement of said rotary engine causes said reading head to follow a video disk track and ensures that the speed is kept constant.
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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) | 1986-04-25 | 1986-10-25 | 1987-04-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-04-25 | 1990-10-25 | 1991-04-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-04-25 | 1994-10-25 | 1995-04-26 | $7700.00 | Window Closed / Lapsed |