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 Title: |
US3873765:
DISC PLAYBACK SYSTEM WITH SPEED CONTROL OF A BELT DRIVE
[ Derwent Title ]
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| Country: |
US United States of America
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| Inventor: |
Schoop, James Conrad; Indianapolis, IN
Stave, Frederick Roland; Indianapolis, IN
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| Assignee: |
RCA Corporation, New York, NY
other patents from RCA CORPORATION (466175) (approx. 7,929)
News, Profiles, Stocks and More about this company
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| Published / Filed: |
1975-03-25
/ 1974-06-18
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| Application Number: |
US1974000480329
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| IPC Code: |
Advanced:
G11B 19/24;
G11B 19/28;
H04N 5/781;
Core:
more...
IPC-7:
G11B 17/00;
H02K 7/10;
H04N 5/76;
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| U.S. Class: |
Current:
369/239;
348/531;
360/073.03;
360/086;
369/126;
369/266;
369/268;
386/E05.042;
388/822;
388/932;
G9B/019.039;
G9B/019.046;
Original:
178/006.6A;
179/100.1S;
179/100.4E;
318/302;
360/073;
360/086;
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| Field of Search: |
178/6.6 P,6.6 DD
360/073,70,84,86
274/1 D,1 E,1 F,9 A
179/100.1 S,100.4 E,100.4 D
318/302
358/008
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| Priority Number: |
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| Abstract: |
A speed control system for a video disc playback system utilizes a speed change mechanism which permits the speed of the disc turntable to be varied without affecting the speed of the drive motor. A drive belt is coupled in non-slip relation to the disc turntable and the drive motor causing 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. A brake mechanism adjusts the speed of rotation of the turntable to control the speed of the relative motion between the disc record and the pickup device. The drive belt is yieldable such that the turntable can be adjusted to have a speed of rotation which is asynchronous with respect to the speed of rotation of the drive motor.
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| Attorney, Agent or Firm: |
Whitacre, Eugene M. ;
Meagher, William H. ;
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| Primary / Asst. Examiners: |
Cardillo, Jr., Raymond F.;
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| INPADOC Legal Status: |
None
Family Legal Status Report
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| Parent Case: |
This is a continuation of application Ser. No. 284,509, filed 8-29-72 now abandoned.
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| Family: |
Show 19 known family members
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First Claim:
Show all 8 claims |
What is claimed is:
1. In a playback system wherein a prerecorded signal is recovered from a disc record by a pickup device when relative motion is established between said disc record and said pickup device by rotation of a turntable supporting said disc record, said playback system including braking means for controllably applying a braking force to said turntable, said braking means being responsive to the output of a speed detecting means for varying the effect of said braking force in accordance with deviations of the velocity of said relative motion from a desired operating velocity; a drive system comprising:
- a pulley;
- a motor, subject to substantially constant frequency energization independent of the output of said speed detecting means, for rotating said pulley;
- a belt of elastic material stretched to encircle respective cylindrical surfaces of said turntable and said pulley, the diameter of said cylindrical surface of said turntable exceeding the diameter of said cylindrical surface of said pulley, for transmitting rotational motion to said turntable in a manner establishing a given step-down ratio between the respective rotational rates of said pulley and turntable when said motor is subjected to said energization in the absence of operation of said braking means, said given ratio being chosen to establish said relative motion between said disc record and said pickup device at a given velocity exceeding said desired operating velocity; and
- the length of said belt, the distance between the axes of rotation of said pulley and said turntable, and the elasticity of said belt material being so related as to permit the ratio of rotational rates of said pulley and turntabe to vary over a range of ratios differing from said given step-down ratio, when said motor is subject to said energization in the presence of operation of said braking means, without slippage between said belt and said cylindrical surfaces.
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| Background / Summary: |
Show background / summary
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| Drawing Descriptions: |
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| Description: |
Show description
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| Forward References: |
Show 3 U.S. patent(s) that reference this one
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