US4366513A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tape recorder with noise blanking circuit
Assignee: Olympus Corp
•
Filing: 1979-05-22
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Granted: 1982-12-28
•
Expires: 1999-05-22
Abstract
Abstract The disclosed tape recorder serves for supplying a microphone output to a recording and reproducing head through an amplifier during recording by switching a recording and reproducing switch. A noise removing circuit at the output of said amplifier suppresses the output from the amplifier to the head a predetermined time during application of an electric power supply source of the amplifier.
Inventors
- 👤 Ken Satoh
- 👤 Shunichi Orita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:11
CPC Classifications
G; G11; G11B; G11B20/00; G11B20/24
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
66 words
In a tape recorder which supplies an erasing current from an electric power supply source to an erasing head by switching a recording and reproducing switch at the time of recording, the improvement comprising a noise removing circuit at an input of said erasing head for momentarily suppressing and then increasing the erasing current to a predetermined value by switching on said electric power supply source.
Claim 2
Dependent Claim
66 words
In a tape recorder which supplies an erasing current from an electric power supply source to an erasing head by switching a recording and reproducing switch at the time of recording, the improvement comprising a noise removing circuit at an input of said erasing head for momentarily suppressing and then increasing the erasing current to a predetermined value by switching on said electric power supply source.
Claim 3
Dependent Claim
46 words
A tape recorder as claimed in claim 1, wherein said noise removing circuit comprises a capacitor arranged to be simultaneously charged by the input of said electric power supply source and a switching element arranged to become conductive in response to charging current of the capacitor.
Claim 4
Dependent Claim
68 words
A device as in claim 1, wherein said recorder includes an erasing oscillator, wherein said noise removing current includes a transistor circuit connected directly to the output of the oscillator, said transistor circuit having a transistor with a control electrode and two other electrodes, an RC circuit forming a junction at the control electrode and a capacitor connected from the control electrode to one of the other electrodes.
Claim 5
Dependent Claim
28 words
A device as in claim 3, wherein said other electrode is the collector of said transistor, and the transistor circuit is connected across the output of the oscillator.
Claim 6
Dependent Claim
31 words
A device as in claim 3, wherein the other electrode is the emitter and said transistor is connected so that its emitter collector circuit is in series with the erasing head.
References Cited (Backward Citations)
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Cited
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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) | 1985-12-27 | 1986-06-28 | 1986-12-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-12-27 | 1990-06-28 | 1990-12-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-12-27 | 1994-06-28 | 1994-12-28 | $7700.00 | Window Closed / Lapsed |