US4114830A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rotation control system
Assignee: Nippon Gakki Co Ltd
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Filing: 1977-05-31
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Granted: 1978-09-19
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Expires: 1997-05-31
Abstract
Abstract In a tape recorder, the rotation of a tape reel is detected and converted to a pulse signal having a repetition frequency proportional to the rotation speed of the tape reel. This pulse signal is supplied to a pair of frequency-voltage converters having different time constants to provide different outputs therefrom. The rotation of the tape reel is controlled by braking the rotation of the tape reel with a force proportional to the difference of the above two outputs.
Inventors
- 👤 Juro Hoshi
- 👤 Makoto Watanabe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 08:46
CPC Classifications
G; G11; G11B; G11B15/00; G11B15/18; G11B15/46; G11B15/50; G11B15/54; G11B20/00; G11B20/22; G11B20/225
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
75 words
A rotation control system for a rotating member, comprising: detection means for generating a pulse signal having a frequency corresponding to the rotation speed of said rotating member; a plurality of frequency-voltage converters responsive to said pulse signal, for generating a signal representing the rate of change of said rotation speed; and braking means, responsive to said signal representing the rate of change of said rotation speed, for controllably effecting braking of said rotating member.
Claim 2
Dependent Claim
75 words
A rotation control system for a rotating member, comprising: detection means for generating a pulse signal having a frequency corresponding to the rotation speed of said rotating member; a plurality of frequency-voltage converters responsive to said pulse signal, for generating a signal representing the rate of change of said rotation speed; and braking means, responsive to said signal representing the rate of change of said rotation speed, for controllably effecting braking of said rotating member.
Claim 3
Dependent Claim
18 words
A rotation control system according to claim 1, wherein said plurality of frequency-voltage converters have different time constants.
Claim 4
Dependent Claim
17 words
A rotation control system according to claim 2, wherein said plurality of frequency-voltage converters are low-pass filters.
Claim 5
Dependent Claim
22 words
A rotation control system according to claim 2, wherein said braking means is an eddy current brake connected to said rotating member.
Claim 6
Dependent Claim
60 words
A rotation control system according to claim 2, wherein said detector means comprises a magnetic flux generating means coupled to said rotating member for generating changes of magnetic flux at a predetermined position and a magnetic flux detection means disposed at said predetermined position for generating said pulse signal having the frequency representing the rotation speed of said rotating member.
Claim 7
Dependent Claim
54 words
A rotation control system according to claim 2, wherein said detector means comprises a light pulse generating means for generating light pulses of a frequency corresponding to the rotation speed of said rotating member and a photoelectric converter for receiving said light pulses and for generating an electric signal corresponding to the light pulses.
Claim 8
Dependent Claim
31 words
A rotation control system according to claim 2, further comprising a biasing braking means for generating a braking force corresponding to the output of one of said plurality of frequency-voltage converters.
Claim 9
Dependent Claim
28 words
A rotation control system according to claim 7, wherein said one of said plurality of frequency-voltage converters has the largest time constant among said plurality of frequency-voltage converters.
Claim 10
Dependent Claim
24 words
A rotation control system according to claim 8, further comprising means for applying a constant braking force to the rotation of said rotating member.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-09-18 | 1982-03-20 | 1982-09-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-09-18 | 1986-03-20 | 1986-09-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-09-18 | 1990-03-20 | 1990-09-19 | $7700.00 | Window Closed / Lapsed |