Patent EP0253751A2 successfully refreshed from Google Patents.
Patent US4511935A successfully refreshed from Google Patents.
US4511935A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tape recorder
Assignee: Olympus Corp
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Filing: 1982-11-18
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Granted: 1985-04-16
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Expires: 2002-11-18
Abstract
Abstract In the disclosed tape recorder, the erase head is supplied with DC erasing current during recording and is connectable with an AC erase unit which supplies AC erasing current instead of the DC erasing current to offer high-quality recording and replay.
Inventors
- 👤 Yougo Imai
- 👤 Hideo Takenaga
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 18:45
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/02; G11B5/024
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
114 words
A tape recorder comprising a recording unit having recording bias oscillating means for supplying an AC recording bias current a recording head for receiving the bias current, and erase head, and erase means for supplying said erase head with DC erasing current during recording; and an AC erase unit which is connectable to said unit for supplying AC erasing current to said erase means instead of said DC erasing current so that said erase means supplies AC erasing current to said erase head, said AC erase unit being conductively coupled to said recording bias oscillatory means for receiving the AC bias current and using the AC bias current to produce the AC erasing current.
Claim 2
Dependent Claim
114 words
A tape recorder comprising a recording unit having recording bias oscillating means for supplying an AC recording bias current a recording head for receiving the bias current, and erase head, and erase means for supplying said erase head with DC erasing current during recording; and an AC erase unit which is connectable to said unit for supplying AC erasing current to said erase means instead of said DC erasing current so that said erase means supplies AC erasing current to said erase head, said AC erase unit being conductively coupled to said recording bias oscillatory means for receiving the AC bias current and using the AC bias current to produce the AC erasing current.
Claim 3
Dependent Claim
42 words
A tape recorder of claim 1, in which said AC erase unit has an auxiliary DC power supply and an amplifier to amplify AC bias current in said bias oscillator circuit of said tape recorder unit and to generate AC erasing current.
Claim 4
Dependent Claim
25 words
A tape recorder of either claim 1 or 2, wherein said AC erase unit is connectable to said tape recorder unit via plug and jack.
Claim 5
Dependent Claim
32 words
A tape recorder of either claim 1, 2, 3, or 6, wherein said AC erase unit is made to be capable to supply auxiliary DC power supply to said tape recorder unit.
Claim 6
Dependent Claim
24 words
A tape recorder as in claim 3, wherein said AC erase unit is coupled to said recording unit exclusively through said plug and jack.
Claim 7
Dependent Claim
133 words
A tape recorder comprising a recording unit having recording bias oscillating means for supplying an AC recording bias current a recording head for receiving the bias current, an erase head, and erase means for supplying said erase head with DC erasing current during recording; and an AC erase unit which is connectable to said unit for supplying AC erasing current to said erase means instead of said DC erasing current so that said erase means supplies AC erasing current to said erase head, said AC erase unit being coupled to said recording bias oscillatory means for receiving the AC bias current and using the AC bias current to produce the AC erasing current, a plug and jack, said according unit and said AC erase means being couplable exclusively through said plug and jack.
Claim 8
Dependent Claim
133 words
A tape recorder comprising a recording unit having recording bias oscillating means for supplying an AC recording bias current a recording head for receiving the bias current, an erase head, and erase means for supplying said erase head with DC erasing current during recording; and an AC erase unit which is connectable to said unit for supplying AC erasing current to said erase means instead of said DC erasing current so that said erase means supplies AC erasing current to said erase head, said AC erase unit being coupled to said recording bias oscillatory means for receiving the AC bias current and using the AC bias current to produce the AC erasing current, a plug and jack, said according unit and said AC erase means being couplable exclusively through said plug and jack.
References Cited (Backward Citations)
US3449529A
Cited
US4258402A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-04-15 | 1988-10-15 | 1989-04-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-04-15 | 1992-10-15 | 1993-04-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-04-15 | 1996-10-15 | 1997-04-16 | $7700.00 | Window Closed / Lapsed |