US3946440A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dual erasing core structure for selectively erasing adjacent recording
Assignee: Canon Inc
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Filing: 1974-12-03
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Granted: 1976-03-23
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Expires: 1994-12-03
Abstract
Abstract A magnetic eraser device comprises a first and a second erase head having respective magnetic gaps therein. The two heads are aligned transversely of a recording track on a magnetic recording medium. The magnetic gaps of the two head are perpendicular to the axis of the recording track and offset from each other. The surfaces of the two erase heads which are opposed to each other are spaced apart a predetermined distance and inclined at a predetermined angle with respect to the axis of the recording track. Alternatively, such surfaces of the two erase heads are spaced apart a predetermined distance but may be parallel to the axis of the recording track and stepped symmetrically between the magnetic gaps.
Inventors
- 👤 Takeshi Saito
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 16:12
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/29; G11B5/02; G11B5/027; G11B5/03
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
200 words
A combination erasing head for selectively erasing a plurality of tracks of a recording medium having parallel first and second tracks provided with a blank section interposed therebetween, comprising: first and second erasing cores for the recording medium, said first erasing core having a first face engaging the recording medium including a portion extending across the first track and one half of the blank section and having an end face formed in a single plane, said second erasing core having a first face engaging the recording medium including a portion extending across the second track and one half of the blank section and having an end face formed in a single plane, said end faces being parallel and opposed adjacent each other; said first erasing core having only one erasing gap, said gap being provided in said portion of said first face and spanning the first track and substantially one half of the blank section; said second erasing core having only one erasing gap, said gap being provided in said portion of said first face and spanning the second track and substantially one half of the blank section, said second erasing gap being spaced longitudinally from said first erasing gap.
Claim 2
Dependent Claim
200 words
A combination erasing head for selectively erasing a plurality of tracks of a recording medium having parallel first and second tracks provided with a blank section interposed therebetween, comprising: first and second erasing cores for the recording medium, said first erasing core having a first face engaging the recording medium including a portion extending across the first track and one half of the blank section and having an end face formed in a single plane, said second erasing core having a first face engaging the recording medium including a portion extending across the second track and one half of the blank section and having an end face formed in a single plane, said end faces being parallel and opposed adjacent each other; said first erasing core having only one erasing gap, said gap being provided in said portion of said first face and spanning the first track and substantially one half of the blank section; said second erasing core having only one erasing gap, said gap being provided in said portion of said first face and spanning the second track and substantially one half of the blank section, said second erasing gap being spaced longitudinally from said first erasing gap.
Claim 3
Dependent Claim
29 words
An erasing head according to claim 1, wherein the end faces of both of said cores are disposed at an angle with respect to the length of the tracks.
Claim 4
Dependent Claim
21 words
An erasing head according to claim 2, wherein said erasing gaps are arranged substantially perpendicular to the length of the tracks.
Claim 5
Dependent Claim
34 words
An erasing head according to claim 2, wherein a line passing through an end of said first gap and an end of said second gap is parallel to the tracks of the recording material.
Claim 6
Dependent Claim
24 words
An erasing head according to claim 2, wherein said erasing gaps are arranged at an angle with respect to the length of the tracks.
Claim 7
Dependent Claim
24 words
An erasing head according to claim 2, wherein said erasing gaps are arranged substantially perpendicular to said end faces of the respective erasing cores.
Claim 8
Dependent Claim
21 words
An erasing head according to claim 2, wherein said first erasing core and said second erasing core have the same configuration.
Claim 9
Dependent Claim
222 words
A combination erasing head for selectively erasing a plurality of tracks of a recording medium having parallel first and second tracks provided with a blank section interposed therebetween, comprising: first and second erasing cores for the recording medium, said first erasing core having a first face engaging the recording medium including a portion extending across the first track and one half of the blank section and having an end face formed in a single plane substantially perpendicular to said first face, said second erasing core having a first face engaging the recording medium including a portion extending across the second track and one half of the blank section and having an end face formed in a single plane substantially perpendicular to its first face and opposing said first erasing core, the end face of said second erasing core being in parallel and adjacent to the end face of said first erasing core; said first erasing core having only a first erasing gap provided in said first face, said gap engaging the first track and substantially one half of the blank section; said second erasing core having only a second erasing gap provided in said first face, said gap engaging the second track and substantially one half of the blank section, said second erasing gap being spaced longitudinally from said first erasing gap.
Claim 10
Dependent Claim
222 words
A combination erasing head for selectively erasing a plurality of tracks of a recording medium having parallel first and second tracks provided with a blank section interposed therebetween, comprising: first and second erasing cores for the recording medium, said first erasing core having a first face engaging the recording medium including a portion extending across the first track and one half of the blank section and having an end face formed in a single plane substantially perpendicular to said first face, said second erasing core having a first face engaging the recording medium including a portion extending across the second track and one half of the blank section and having an end face formed in a single plane substantially perpendicular to its first face and opposing said first erasing core, the end face of said second erasing core being in parallel and adjacent to the end face of said first erasing core; said first erasing core having only a first erasing gap provided in said first face, said gap engaging the first track and substantially one half of the blank section; said second erasing core having only a second erasing gap provided in said first face, said gap engaging the second track and substantially one half of the blank section, said second erasing gap being spaced longitudinally from said first erasing gap.
References Cited (Backward Citations)
DE1167053B
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-03-23 | 1979-09-22 | 1980-03-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-23 | 1983-09-22 | 1984-03-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-23 | 1987-09-22 | 1988-03-23 | $7700.00 | Window Closed / Lapsed |