Patent US4894737A successfully refreshed from Google Patents.
US4894737A
Expired / Lapsed
US
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Magnetic head apparatus having projections extending from at least a front side thereof
Assignee: Canon Inc
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Filing: 1987-12-02
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Granted: 1990-01-16
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Expires: 2007-12-02
Abstract
Abstract This invention proposes to form a pair of protruding or projecting stripe portions along the tape-gliding face of magnetic tape and to reduce the pad pressure to magnetic tape thereby reducing the gliding resistance of magnetic tape without increasing its spacing loss (first embodiment), to incline the plane of the projecting stripe portions in a decreasing direction in the vicinity of the tape-gliding face in order to stabilize the pad contact (second embodiment), to form grooves on the tape-gliding face of the magnetic core in the transversal edge portions at least in the tape entrance side thereby facilitating prevention of tape squeaking (third embodiment), to increase the height of one of the projecting stripe portions in the vicinity of head mounting position compared to that of the other stripe portion thereby preventing one-sided abrasion of the tape-gliding face (fourth embodiment), and to form tape guide members on the magnetic head for guiding the magnetic tape closer to one of the projecting stripe portion at the head mounting position and separate from the other thereby preventing one-sided abrasion of the tape-gliding face (fifth embodiment).
Inventors
- 👤 Junji Hamana
- 👤 Shinichi Hara
- 👤 Makoto Miyagi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 21:13
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/10; G11B15/00; G11B15/60; G11B15/602; G11B15/62; G11B23/00; G11B23/02; G11B23/04; G11B23/08; G11B23/087; G11B23/08707; G11B23/08757; G11B23/08771; G11B5/127; G11B5/187; G11B5/1871
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
140 words
A magnetic head, comprising: a magnetic core having a first contact face for contacting a recording medium; a fixing material surrounding said magnetic core and having a second contact face for contacting the recording medium; and a case housing said magnetic core and said fixing material, provided with an aperture exposing said first contact face of said magnetic core and said second contact face of said fixing material and provided further with a pair of projecting members, each of said projecting members projecting from a position adjacent said aperture and outside a path of the recording medium, wherein said projecting members on said case project from at least one of said first contact face of said magnetic core and said second contact face of said fixing material a distance which is within a range of 0.01 mm to 0.5 mm.
Claim 2
Dependent Claim
140 words
A magnetic head, comprising: a magnetic core having a first contact face for contacting a recording medium; a fixing material surrounding said magnetic core and having a second contact face for contacting the recording medium; and a case housing said magnetic core and said fixing material, provided with an aperture exposing said first contact face of said magnetic core and said second contact face of said fixing material and provided further with a pair of projecting members, each of said projecting members projecting from a position adjacent said aperture and outside a path of the recording medium, wherein said projecting members on said case project from at least one of said first contact face of said magnetic core and said second contact face of said fixing material a distance which is within a range of 0.01 mm to 0.5 mm.
Claim 3
Dependent Claim
170 words
A magnetic head, comprising: a magnetic core having a first contact face for contacting a recording medium; a fixing material surrounding said magnetic core having a second contact face for contacting the recording medium; and a case housing said magnetic core and said fixing material, provided with an aperture exposing said first contact face of said magnetic core and said second contact face of said fixing material and provided further with a pair of projecting members, each of said pair of projecting members having first and second portions, each of said first portions projecting from a position adjacent said aperture and outside a path of the recording medium, said second portions being positioned further from said aperture than are said first portions, wherein each of said projecting members is provided with a face inclined downward toward said aperture such that each of said first portions has a height in a range of 0.01 mm to 0.1 mm and each of said second portions has a height larger than 0.1 mm.
Claim 4
Dependent Claim
170 words
A magnetic head, comprising: a magnetic core having a first contact face for contacting a recording medium; a fixing material surrounding said magnetic core having a second contact face for contacting the recording medium; and a case housing said magnetic core and said fixing material, provided with an aperture exposing said first contact face of said magnetic core and said second contact face of said fixing material and provided further with a pair of projecting members, each of said pair of projecting members having first and second portions, each of said first portions projecting from a position adjacent said aperture and outside a path of the recording medium, said second portions being positioned further from said aperture than are said first portions, wherein each of said projecting members is provided with a face inclined downward toward said aperture such that each of said first portions has a height in a range of 0.01 mm to 0.1 mm and each of said second portions has a height larger than 0.1 mm.
Claim 5
Dependent Claim
137 words
A magnetic head, comprising: a magnetic core having a first contact face for contacting a recording medium; a fixing material surrounding said magnetic core and having a second contact face for contacting the recording medium; a case housing said magnetic core and said fixing material, provided with an aperture exposing said first contact face of said magnetic core and said second contact face of said fixing material and provided further with a pair of projecting members, each of said pair of projecting members projecting from a position adjacent said aperture and outside a path of the recording medium; and at least one groove formed by cutting at least said case along a lateral edge thereof a side where the recording medium enters said case in a direction substantially perpendicular to the running direction of the recording medium.
Claim 6
Dependent Claim
137 words
A magnetic head, comprising: a magnetic core having a first contact face for contacting a recording medium; a fixing material surrounding said magnetic core and having a second contact face for contacting the recording medium; a case housing said magnetic core and said fixing material, provided with an aperture exposing said first contact face of said magnetic core and said second contact face of said fixing material and provided further with a pair of projecting members, each of said pair of projecting members projecting from a position adjacent said aperture and outside a path of the recording medium; and at least one groove formed by cutting at least said case along a lateral edge thereof a side where the recording medium enters said case in a direction substantially perpendicular to the running direction of the recording medium.
Claim 7
Dependent Claim
21 words
A magnetic head according to claim 3, comprising two grooves at positions sandwiching said first contact face of said magnetic care.
Claim 8
Dependent Claim
27 words
A magnetic head according to claim 3, wherein said at least one groove is formed in a position not interrupting the projecting members provided on said case.
Claim 9
Dependent Claim
27 words
A magnetic head according to claim 4, wherein said at least one groove is formed in a position not interrupting the projecting members provided on said case.
Claim 10
Dependent Claim
145 words
A magnetic head, comprising: a magnetic core having a first contact face for contacting a recording medium; a fixing material surrounding said magnetic core and having a second contact face for contacting the recording medium; a case housing said magnetic core and said fixing material, provided with an aperture exposing said first contact face of said magnetic core and said second contact face of said fixing material and provided further with a pair of projecting members, each of said projecting members projecting from a position adjacent said aperture and outside a path of the recording medium; and mounting means for mounting said case on another apparatus; wherein the height of one of said pair of projecting members on said case, closer to said mounting means, is larger by an amount ranging from 0.01 mm to 0.3 mm than the height of the other projecting member.
Claim 11
Dependent Claim
145 words
A magnetic head, comprising: a magnetic core having a first contact face for contacting a recording medium; a fixing material surrounding said magnetic core and having a second contact face for contacting the recording medium; a case housing said magnetic core and said fixing material, provided with an aperture exposing said first contact face of said magnetic core and said second contact face of said fixing material and provided further with a pair of projecting members, each of said projecting members projecting from a position adjacent said aperture and outside a path of the recording medium; and mounting means for mounting said case on another apparatus; wherein the height of one of said pair of projecting members on said case, closer to said mounting means, is larger by an amount ranging from 0.01 mm to 0.3 mm than the height of the other projecting member.
Claim 12
Dependent Claim
163 words
A magnetic head, comprising: a magnetic core having a first contact face for contacting a recording medium; a fixing material surrounding said magnetic core and having a second contact face for contacting the recording medium; a case housing said magnetic core and said fixing material, provided with an aperture exposing said first contact face of said magnetic core and said second contact face of said fixing material and provided further with a pair of projecting members, each of said projecting members projecting from a position adjacent said aperture and outside a path of the recording medium; mounting means for mounting said case on another apparatus; and tape guide members provided on lateral faces of said case, for guiding the recording medium to a position closer to one of said pair of projecting members, which is positioned closer to said mounting means than the other of said pair of projecting members, than a central position between said pair of projecting members on said case.
Claim 13
Dependent Claim
163 words
A magnetic head, comprising: a magnetic core having a first contact face for contacting a recording medium; a fixing material surrounding said magnetic core and having a second contact face for contacting the recording medium; a case housing said magnetic core and said fixing material, provided with an aperture exposing said first contact face of said magnetic core and said second contact face of said fixing material and provided further with a pair of projecting members, each of said projecting members projecting from a position adjacent said aperture and outside a path of the recording medium; mounting means for mounting said case on another apparatus; and tape guide members provided on lateral faces of said case, for guiding the recording medium to a position closer to one of said pair of projecting members, which is positioned closer to said mounting means than the other of said pair of projecting members, than a central position between said pair of projecting members on said case.
Claim 14
Dependent Claim
77 words
A magnetic head according to claim 8, wherein said tape guide members are so positioned that a quantity l 2 is in a range of 1.1l 1 to 5l 1 , where l 1 is the distance from a lateral edge of the recording medium to one of said pair of projecting members and l 2 is the distance from the other lateral edge of the recording medium to the other of said pair of projecting members.
Claim 15
Independent Claim
105 words
An apparatus utilizing a magnetic head, comprising: a magnetic head capable of electromagnetic conversion; and a loading means for loading a cassette, the cassette including (i) a recording medium to be maintained in gliding contact with said magnetic head and (ii) a pad for maintaining the recording medium in pressure contact with said magnetic head, wherein said magnetic head is provided with a pair of projecting members fixedly mounted to said magnetic head and adapted to contact the pad incorporated in the cassette in plural positions thereby reducing the contact pressure of the pad while maintaining a sufficient contact pressure for pressing the recording medium.
Claim 16
Independent Claim
105 words
An apparatus utilizing a magnetic head, comprising: a magnetic head capable of electromagnetic conversion; and a loading means for loading a cassette, the cassette including (i) a recording medium to be maintained in gliding contact with said magnetic head and (ii) a pad for maintaining the recording medium in pressure contact with said magnetic head, wherein said magnetic head is provided with a pair of projecting members fixedly mounted to said magnetic head and adapted to contact the pad incorporated in the cassette in plural positions thereby reducing the contact pressure of the pad while maintaining a sufficient contact pressure for pressing the recording medium.
Claim 17
Dependent Claim
31 words
An apparatus according to claim 10, wherein said pair of projecting members formed on said magnetic head project a distance which is in a range from 0.01 mm to 0.5 mm.
Claim 18
Dependent Claim
24 words
An apparatus according to claim 10, wherein said pair of projecting members formed on said magnetic head including upper end faces mutually inclined inwards.
Claim 19
Independent Claim
104 words
An apparatus utilizing a magnetic head, comprising: a magnetic head capable of electromagnetic conversion; a maintaining means for maintaining a recording medium in gliding contact with said magnetic head and adapted to be used with a pad incorporated in a cassette for maintaining the recording medium in pressure contact with said magnetic head, said maintaining means being provided with a socket for a capstan for conveying the recording medium; pressure reducing means for reducing the contact pressure on the recording medium exerted by the pad incorporated in the cassette, by an increasing degree at a position on said magnetic head closer to said socket.
Claim 20
Independent Claim
104 words
An apparatus utilizing a magnetic head, comprising: a magnetic head capable of electromagnetic conversion; a maintaining means for maintaining a recording medium in gliding contact with said magnetic head and adapted to be used with a pad incorporated in a cassette for maintaining the recording medium in pressure contact with said magnetic head, said maintaining means being provided with a socket for a capstan for conveying the recording medium; pressure reducing means for reducing the contact pressure on the recording medium exerted by the pad incorporated in the cassette, by an increasing degree at a position on said magnetic head closer to said socket.
Claim 21
Dependent Claim
44 words
An apparatus according to claim 13, wherein said pressure reducing means is composed of a pair of projecting members, each of said pair of projecting members projecting from the front face of said magnetic head, for engaging with the pad incorporated in the cassette.
Claim 22
Dependent Claim
34 words
An apparatus according to claim 14, wherein the distance said projecting members project is larger at a position closer to said socket of said apparatus and smaller at a position farther from said socket.
Claim 23
Dependent Claim
50 words
An apparatus according to claim 14, wherein said pressure reducing means further comprising tape guide members formed on lateral faces of said magnetic head for guiding the recording medium incorporated in the cassette to a position closer to one of said projecting positioned closer to said socket of said apparatus.
References Cited (Backward Citations)
DE1124253B
Cited
JPS55150126A
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JPS60106057A
Cited
JPS6113465A
Cited
JPS61134909A
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JPS61200458A
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JPS62192906A
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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) | 1993-01-15 | 1993-07-17 | 1994-01-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-01-15 | 1997-07-17 | 1998-01-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-01-15 | 2001-07-17 | 2002-01-16 | $7700.00 | Window Closed / Lapsed |