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 Title: |
US4123779:
Turntable rotational speed and phase control system for a video disc play/record apparatus
[ Derwent Title ]
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| Country: |
US United States of America
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| Inventor: |
Goldschmidt, Arthur M.; Moorestown, NJ
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| Assignee: |
RCA Corporation, New York, NY
other patents from RCA CORPORATION (466175) (approx. 7,929)
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| Published / Filed: |
1978-10-31
/ 1977-03-14
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| Application Number: |
US1977000777478
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| IPC Code: |
Advanced:
G11B 19/24;
G11B 19/28;
H04N 5/76;
Core:
more...
IPC-7:
G11B 17/00;
G11B 19/28;
H04N 5/76;
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| ECLA Code: |
G11B19/24;
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| U.S. Class: |
Current:
386/125;
360/073.03;
369/126;
369/241;
G9B/019.039;
Original:
358/128;
179/100.1S;
179/100.4E;
179/100.3V;
360/073;
318/314;
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| Field of Search: |
358/128
179/100.1 S,100.4 E,100.4 D,100.3 V
360/073,75,70
318/314,318
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| Priority Number: |
| 1976-03-19 |
GB1976000011105 |
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| Abstract: |
Video disc play/record apparatus includes a turntable driven by a uni-directional DC motor, a speed loop for controlling motor rotation responsively to horizontal sync signal and a position loop for controlling the rotational phase of the turntable responsively to a frame sync signal. The speed loop comprises a motor driven tachometer whose output is stabilized by a phase locked loop about a nominal frequency. A phase and frequency difference detector, responsive to the phase locked loop output and the horizontal sync signal, provides a driving voltage to power amplifiers coupled to the motor. The position loop includes means cooperating with the speed loop to regulate the turntable phase of rotation responsively to the phase difference between the outputs of a turntable tachometer and a frame and vertical sync signal source. Delay circuits in the speed and position loops provide compensation for detected disc mounting error between a previous recording mounting position and the current mounting position of the disc on the turntable. A by-pass circuit directly powers the motor during start-up operations. Stopping and overspeed protection are accomplished by inhibiting the power amplifiers and coupling a source of reverse potential to the motor.
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| Attorney, Agent or Firm: |
Whitacre, Eugene M. ;
Meagher, William H. ;
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| Primary / Asst. Examiners: |
Konick, Bernard; Faber, Alan
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| INPADOC Legal Status: |
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| Family: |
Show 9 known family members
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First Claim:
Show all 18 claims |
What is claimed is:
1. In a disc record player and recorder apparatus operable in either of an information recording or recovery mode for use with a source of frames of composite video signals including horizontal and vertical synchronization pulses and means for providing a frame synchronization signal; and apparatus comprising the combination:
- a turntable;
- means for rotating said turntable;
- means for synchronizing the speed of rotation of said turntable in response to synchronization pulses derived from said source;
- means, cooperating with said turntable; for providing a signal responsive to the rotation of the turntable;
- means, cooperating with said rotating means, for altering the phase of rotation of said turntable;
- first means for rendering said phase altering means responsive to the phase difference between said rotation responsive signal and said frame synchronization signal; and
- second means for rendering said phase altering means additionally responsive to the relative position of a predetermined sector of a disc, supported on said turntable, with respect to a predetermined sector of said turntable.
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| Background / Summary: |
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| Drawing Descriptions: |
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| Description: |
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| Forward References: |
Show 29 U.S. patent(s) that reference this one
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