Patent US4135218A successfully refreshed from Google Patents.
US4135218A
Expired / Lapsed
US
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Magnetic recording and reproducing apparatus
Assignee: Fujifilm Holdings Corp
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Filing: 1976-05-19
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Granted: 1979-01-16
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Expires: 1996-05-19
Abstract
Abstract A magnetic recording and reproducing apparatus provided with a magnetic head device comprising a supporting means having a recording magnetic head made of an alloy system magnetic material and a reproducing magnetic head made of a ferrite system magnetic material. The recording and reproducing heads are fixed relative to one another thereby eliminating the need for completely separate head mechanisms and for complex mechanisms to reliably interchange the positions of the two heads relative to the recording medium.
Inventors
- 👤 Matsuaki Nakamura
- 👤 Tatsuji Kitamoto
- 👤 Yasuo Tamai
- 👤 Koshu Kurokawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 10:30
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/48; G11B5/52; G11B5/53; G11B5/531; G11B5/488; G11B5/54; G11B5/55; G11B5/5521
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
116 words
Apparatus for recording, with high density, and reproducing signals on a magnetic medium, comprising, at least one magnetic recording head and at least one magnetic reproducing head fixedly positioned relative to each other in an orthogonal relationship on a common head support mechanism, said recording head constructed of a first material selected from the group consisting of permalloy, alphenol and sendust and said reproducing head constructed of a second material selected from the group consisting of high density ferrite, single crystal ferrite, hot press ferrite and conventional ferrite providing said recording head with a substantially higher maximum magnetic flux density Bm and a substantially lower permeability μo at high frequencies than those of said reproducing head.
Claim 2
Dependent Claim
116 words
Apparatus for recording, with high density, and reproducing signals on a magnetic medium, comprising, at least one magnetic recording head and at least one magnetic reproducing head fixedly positioned relative to each other in an orthogonal relationship on a common head support mechanism, said recording head constructed of a first material selected from the group consisting of permalloy, alphenol and sendust and said reproducing head constructed of a second material selected from the group consisting of high density ferrite, single crystal ferrite, hot press ferrite and conventional ferrite providing said recording head with a substantially higher maximum magnetic flux density Bm and a substantially lower permeability μo at high frequencies than those of said reproducing head.
Claim 3
Dependent Claim
45 words
Apparatus as claimed in claim 1 wherein said first material is selected from the group consisting of permalloy, alphenol and sendust and wherein said second material is selected from the group consisting of high density ferrite, single crystal ferrite, hot press ferrite and conventional ferrite.
Claim 4
Dependent Claim
70 words
Apparatus as claimed in claim 1 wherein said support mechanism comprises a rotatable cross arm having four extremities defining the points of 0°, 90°, 180° and 270° of a circle, said at least one magnetic recording head comprising two magnetic recording heads fixedly positioned at the 0° and 180° extremities, said at least one magnetic reproducing head comprising two magnetic reproducing heads fixedly positioned at the 90° and 270° extremities.
Claim 5
Dependent Claim
127 words
Apparatus as claimed in claim 3 further comprising means for rotating said cross arm to cause said recording and reproducing heads to have the locus of a single circumference of a circle, first and second drums having equal circumferences which are approximately the same as said locus circumference, said first and second drums being postioned to provide a space therebetween wherein said cross arm rotates, and means helically winding a magnetic tape slightly more than half way around the combination of said drums and space to cause said heads to trace an angular track across said tape, and electronic servo and synchronizing means for positioning said recording heads and reproducing heads at the identical positions of one another relative to said tape during recording and reproducing, respectively.
Claim 6
Dependent Claim
82 words
Apparatus as claimed in claim 1 wherein said support mechanism comprises an arm means, said magnetic recording and reproducing heads being fixedly positioned on said arm separated by a space E, a rotatable shaft having disc holding means thereon for holding and rotating a magnetic recording disc, said arm and said rotatable shaft being controllably positioned relative to one another so that circumferential tracks on said disc are brought into magnetic recording and reproducing access of said magnetic recording and reproducing heads.
Claim 7
Dependent Claim
43 words
Apparatus as claimed in claim 5 further comprising electronic control means selectably actuable into a recording mode and a reproducing mode for laterally positioning said recording and reproducing heads to have identical positions relative to said disc tracks during recording and reproducing, respectively.
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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) | 1982-01-15 | 1982-07-17 | 1983-01-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-01-15 | 1986-07-17 | 1987-01-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-01-15 | 1990-07-17 | 1991-01-16 | $7700.00 | Window Closed / Lapsed |