US4829392A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording apparatus
Assignee: Kenwood KK
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Filing: 1987-05-22
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Granted: 1989-05-09
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Expires: 2007-05-22
Abstract
Abstract Magnetic recording apparatus to improve the reproduction characteristics in an AC bias magnetic head recording. The apparatus includes an AC bias signal oscillator for suppressing an AC bias current which flows in a magnetic head when a record signal has a high frequency and also a large amplitude.
Inventors
- 👤 Yasutaka Kuniharu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 18:06
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/02; G11B5/027; G11B5/03
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
146 words
A magnetic recording apparatus including a recording magnetic head, an AC bias constant current source for supplying an AC bias current to said magnetic head, and an AC bias current bypass circuit connected in shunt to said magnetic head for bypassing part of the AC bias current supplied by said AC bias source to reduce the AC bias current which flows through said magnetic head, wherein said bypass circuit comprises: peak-hold means including capacitance means connected in shunt to said magnetic head for holding the peak value of an AC bias voltage across said magnetic head, and a discharge circuit connected across said capacitance means and including switching means which turns on in response to a predetermined large amplitude and high frequency reporting signal to discharge the peak value in said capacitance means so that part of the AC bias current flows into said capacitance means.
Claim 2
Dependent Claim
146 words
A magnetic recording apparatus including a recording magnetic head, an AC bias constant current source for supplying an AC bias current to said magnetic head, and an AC bias current bypass circuit connected in shunt to said magnetic head for bypassing part of the AC bias current supplied by said AC bias source to reduce the AC bias current which flows through said magnetic head, wherein said bypass circuit comprises: peak-hold means including capacitance means connected in shunt to said magnetic head for holding the peak value of an AC bias voltage across said magnetic head, and a discharge circuit connected across said capacitance means and including switching means which turns on in response to a predetermined large amplitude and high frequency reporting signal to discharge the peak value in said capacitance means so that part of the AC bias current flows into said capacitance means.
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) | 1992-05-08 | 1992-11-07 | 1993-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-08 | 1996-11-07 | 1997-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-08 | 2000-11-07 | 2001-05-09 | $7700.00 | Window Closed / Lapsed |