 |
|
|
|
|
|
 Title: |
US3829612:
VIDEO DISC PLAYBACK EDDY CURRENT SPEED CONTROL SYSTEM
[ Derwent Title ]
|
| Country: |
US United States of America
|
| |
| Inventor: |
Beyers, Jr., Billy Wesley; Greenfield, IN
|
| Assignee: |
RCA Corporation, New York, NY
other patents from RCA CORPORATION (466175) (approx. 7,929)
News, Profiles, Stocks and More about this company
|
| Published / Filed: |
1974-08-13
/ 1972-08-29
|
| Application Number: |
US1972000284510
|
| IPC Code: |
Advanced:
G11B 19/24;
G11B 19/28;
H02P 29/00;
H04N 5/76;
H04N 5/781;
Core:
more...
IPC-7:
G11B 17/00;
H02K 7/104;
H04N 5/76;
|
| U.S. Class: |
Current:
386/087;
360/073.03;
369/266;
369/268;
388/822;
388/932;
G9B/019.039;
Original:
178/006.6A;
178/005.4CD;
179/100.1S;
179/100.4E;
318/302;
360/033;
360/073;
|
| Field of Search: |
178/6.6 A,6.6 DD,6.6 P,5.4 CD
274/1 D,1 E,1 F,9 A
179/100.1 S,100.4 D,100.4 E
318/302
|
| Priority Number: |
| 1972-04-19 |
GB1972000018045 |
|
| Abstract: |
A speed control system is provided for a video disc playback system. A motor is mechanically coupled to a conductive turntable and drives the turntable to rotate and thereby establish a relative motion between a video disc record mounted on the turntable and a pickup device. The free running speed of the turntable is above the normal operating speed required for proper operation of the playback system. An error signal representative of the speed of the relative motion between the disc record and the pickup device is applied to a magnetic field generating structure. The resulting magnetic field establishes eddy currents in the conductive turntable which creates a braking force which tends to oppose the rotation of the turntable.
|
| Attorney, Agent or Firm: |
Whitacre, E. M. ;
Pitchnik, D. E. ;
Meagher, W. H. ;
|
| Primary / Asst. Examiners: |
Cardillo, Jr., Raymond F.;
|
| INPADOC Legal Status: |
None
Family Legal Status Report
|
| Family: |
Show 18 known family members
|
First Claim:
Show all 5 claims |
What is claimed is:
1. In a video disc playback system wherein a prerecorded video signal is recovered from a disc record by a pickup device when relative motion is established between said disc record and said pickup device and wherein a predetermined speed of said relative motion is required for proper operation of said system, a speed control system comprising:
- a turntable structure for supporting said disc record, said turntable structure having a conductive portion;
- means including a motor coupled to said turntable for driving said turntable to rotate and thereby establish a relative motion between said disc record and said pickup device, the free running speed of said turntable causing the speed of said relative motion to be above said predetermined speed;
- means for adjusting the speed of rotation of said turntable to control the speed of said relative motion between said disc record and said pickup device; said adjusting means comprising means for generating a magnetic field which establishes eddy currents in said conductive portion which create a force tending to oppose the rotation of said turntable;
- means responsive to deviations of the speed of said relative motion from said predetermined speed for altering the duty cycle of energization of said magnetic field generating means to vary said rotation opposing force in a sense tending to reduce said deviations of the speed of said relative motion from said predetermined speed.
|
| Background / Summary: |
Show background / summary
|
| Drawing Descriptions: |
Show drawing descriptions
|
| Description: |
Show description
|
| Forward References: |
Show 7 U.S. patent(s) that reference this one
|
