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 Title: |
US3806668:
INFORMATION PLAYBACK SYSTEM
[ Derwent Title ]
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| Country: |
US United States of America
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| Inventor: |
Hilliker, Stephen Earl; Mooresville, IN
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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: |
1974-04-23
/ 1972-06-01
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| Application Number: |
US1972000258645
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| IPC Code: |
Advanced:
G11B 3/00;
G11B 9/06;
H04N 5/18;
H04N 5/76;
H04N 5/91;
H04R 1/02;
Core:
G11B 9/00;
more...
IPC-7:
G11B 3/00;
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| U.S. Class: |
Current:
369/126;
369/129;
386/E05.003;
386/E05.068;
Original:
179/100.4;
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| Field of Search: |
179/100.4 M,100.4 D
274/9 R
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| Priority Number: |
| 1972-04-19 |
GB1972000018037 |
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| Abstract: |
Information is recorded as capacitive variations in a spiral groove on a disc record. The capacitive variations are detected by a tracking stylus and coupled to a stage including a source applying signals to a tuned circuit. The detected capacitive variations cause signals modulated by the record information to develop in the tuned circuit. The stage is controlled so that a predetermined relationship is maintained between the signals applied to the tuned circuit and the tuned circuit response.
The tuned circuit may include a transmission line to minimize the total shunt capacity of the circuit. This increases the percentage modulation of the signals developed in the tuned circuit by increasing the ratio of the detected capacitive variations to the total shunt capacity of the tuned circuit.
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| Attorney, Agent or Firm: |
Whitacre, Eugene M. ;
Meagher, William H. ;
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| Primary / Asst. Examiners: |
Shaw, Gareth D.; Nusbaum, Mark Edward
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| INPADOC Legal Status: |
None
Family Legal Status Report
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| Family: |
Show 19 known family members
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First Claim:
Show all 12 claims |
1. An information playback system, comprising:
- a disc record having a spiral groove with video information recorded therein over a band of frequencies as capacitive variations;
- means for rotating said disc record;
- a tracking stylus engaging said record groove for detecting the capacitive variations as said disc record is rotated;
- a detector and tuned circuit stage coupled to said stylus;
- an oscillator stage providing output signals, said oscillator stage tunable over a band of frequencies;
- means coupling the output signals from said oscillator stage to said detector and tuned circuit stage;
- an automatic frequency control stage coupled between said detector and tuned circuit stage and said oscillator stage, said automatic frequency control stage controlling the operating frequency of said oscillator stage in response to frequency changes in said detector and tuned circuit stage;
- an automatic gain control stage coupled between said coupling means and said oscillator stage, said automatic gain control stage maintaining the amplitude of said oscillator stage output signals coupled to said detector and tuned circuit stage at a constant level;
- a search control stage coupled to said oscillator stage, said search control stage operable to tune said oscillator stage to an initial condition such that the frequency of said oscillator output signals are within the operating range of said automatic frequency control stage when the frequency separation between the frequency of said oscillator stage output signals and the nominal center frequency of said tuned circuit exceeds a predetermined limit; and
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| Background / Summary: |
Show background / summary
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| Drawing Descriptions: |
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| Description: |
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| Forward References: |
Show 27 U.S. patent(s) that reference this one
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