US4316143A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Speed deviation detector for servo controlled disc mastering turntable
Assignee: RCA Corp
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Filing: 1980-05-29
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Granted: 1982-02-16
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Expires: 2000-05-29
Abstract
Abstract Variations of the speed of a video disc mastering turntable which lie within the lock range of a phase-lock-loop turntable speed control servo are detected by sensing variations of the loop phase detector waveform symmetry. Speed error limits are established by pulse forming circuitry which continuously restarts a timing circuit in one mode of operation and allows the timing circuit to complete a timing cycle in another mode of operation. A further timing circuit is arranged to reject multiple indications of the same speed error whereby a single output indication is provided for all speed errors occurring in a certain time period.
Inventors
- 👤 Richard M. Castle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 13:55
CPC Classifications
G; G11; G11B; G11B19/00; G11B19/20; G11B19/28; G01; G01P; G01P3/00; G01P3/42; G01P3/56; H; H02; H02P; H02P23/00; H02P23/18; H02P23/186
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
120 words
A detector for detecting speed errors of a PLL servo controlled turntable, said PLL servo having a given phase lock range, said detector comprising: phase detector means in said PLL servo responsive to a reference signal and a turntable speed indicating signal supplied thereto for producing a control signal for regulating the speed of said turntable, said control signal exhibiting symmetry variations characteristic of said speed errors; and symmetry deviation detection means responsive to said control signal for providing a first output signal manifestation when said symmetry variations are within predetermined limits and a second output signal manifestation when said symmetry variations exceed said predetermined limits, said predetermined limits lying within said given phase lock range of said PLL servo.
Claim 2
Dependent Claim
120 words
A detector for detecting speed errors of a PLL servo controlled turntable, said PLL servo having a given phase lock range, said detector comprising: phase detector means in said PLL servo responsive to a reference signal and a turntable speed indicating signal supplied thereto for producing a control signal for regulating the speed of said turntable, said control signal exhibiting symmetry variations characteristic of said speed errors; and symmetry deviation detection means responsive to said control signal for providing a first output signal manifestation when said symmetry variations are within predetermined limits and a second output signal manifestation when said symmetry variations exceed said predetermined limits, said predetermined limits lying within said given phase lock range of said PLL servo.
Claim 3
Dependent Claim
94 words
A detector as recited in claim 1 wherein said symmetry deviation detection means comprises: pulse forming means responsive to a transition in either sense of said control signal for producing a trigger pulse, each trigger pulse having a width substantially less than one half period of said control signal; and retriggerable multivibrator means responsive to the trigger pulses produced by said pulse forming means for producing said output signal manifestations, said retriggerable multivibrator means having a predetermined quasi-stable state lying within a range between one half and one full period of said control signal.
Claim 4
Dependent Claim
58 words
A detector as recited in claim 2 further comprising: circuit means for producing a single output error signal manifestation in response to a number N of said second output signal manifestations produced by said multivibrator means occurring within a time t, N being at least one, t being greater than said one full period of said control signal.
Claim 5
Dependent Claim
23 words
A detector as recited in claim 3 further comprising: counter means for counting the output error signal manifestations produced by said circuit means.
Claim 6
Dependent Claim
32 words
A detector as recited in claim 4 further comprising: display means responsive to the count in said counter means for providing a visual indication of at least one value of the count.
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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) | 1985-02-15 | 1985-08-17 | 1986-02-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-02-15 | 1989-08-17 | 1990-02-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-02-15 | 1993-08-17 | 1994-02-16 | $7700.00 | Window Closed / Lapsed |