US4777553A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic head
Assignee: Hitachi Ltd
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Filing: 1986-10-16
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Granted: 1988-10-11
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Expires: 2006-10-16
Abstract
Abstract A magnetic head for reading-out information magnetically recorded on a magnetic recording medium in a waveform varying between two different phases. The magnetic head includes at least one block of high magnetic permeability disposed adjacent to and directly facing a surface of the magnetic recording medium to be read-out so as to provide a magnetic path for passing therethrough magnetic flux emanating from the magnetic record on the magnetic recording medium. A magnetic material member is disposed adjacent to the at least one block so as to cause the magnetic flux emanating from the magnetic record on the magnetic recording medium to pass therethrough and is responsive to transition of the magnetic flux corresponding to variation from one phase to another phase in the waveform representing the recorded information so as to provide a predetermined physical effect. Further, a detecting arrangement is provided for the detecting the predetermined physical effect.
Inventors
- 👤 Hajime Aoi
- 👤 Fumio Kugiya
- 👤 Takashi Tamura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 11:07
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/1278; G11B11/00; G11B11/10; G11B11/105; G11B11/10532; G11B11/10541; G11B11/10543; G11B11/10547; G11B5/33; G11B5/39; G11B5/31; G11B5/3176; G11B5/3179; G11B5/3183
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
164 words
A magnetic head for reading out information magnetically recorded on a magnetic recording medium in a waveform varying between two different phases, said head comprising: two blocks of high magnetic permeability disposed adjacent to and directly facing a surface of said magnetic recording medium to be read-out so as to provide a magnetic path for passing therethrough magnetic flux emanating from the magnetic record on said magnetic recording medium, said blocks being separated by an air gap extending perpendicularly to the surface of said magnetic recording medium; magnetic means of magnetic material disposed in said air gap between said two blocks so as to cause the magnetic flux emanating from said magnetic record on said magnetic recording medium to pass therethrough, and responsive to transistion of the magnetic flux corresponding to variation from one to the other phase in the waveform representing the recorded information to provide a predetermined physical effect, and means for detecting the predetermined physical effect provided by said magnetic means.
Claim 2
Dependent Claim
164 words
A magnetic head for reading out information magnetically recorded on a magnetic recording medium in a waveform varying between two different phases, said head comprising: two blocks of high magnetic permeability disposed adjacent to and directly facing a surface of said magnetic recording medium to be read-out so as to provide a magnetic path for passing therethrough magnetic flux emanating from the magnetic record on said magnetic recording medium, said blocks being separated by an air gap extending perpendicularly to the surface of said magnetic recording medium; magnetic means of magnetic material disposed in said air gap between said two blocks so as to cause the magnetic flux emanating from said magnetic record on said magnetic recording medium to pass therethrough, and responsive to transistion of the magnetic flux corresponding to variation from one to the other phase in the waveform representing the recorded information to provide a predetermined physical effect, and means for detecting the predetermined physical effect provided by said magnetic means.
Claim 3
Dependent Claim
31 words
A magnetic head according to claim 1, wherein said air gap separating said two blocks is a substantially uniform air gap, said magnetic means being disposed only within said air gap.
Claim 4
Dependent Claim
24 words
A magnetic head according to claim 1, wherein said magnetic means provides a magneto-optic effect in response to the transition of the magnetic flux.
Claim 5
Dependent Claim
53 words
A magnetic head according to claim 3, wherein said physical effect detecting means comprises a light system for projecting a polarized light onto said magnetic means and for receiving said polarized light after passing through said magnetic means, and a detector for detecting polarization of said polarized light received by said light system.
Claim 6
Dependent Claim
19 words
A magnetic head according to claim 4, wherein at least one of said blocks is made of transparent material.
Claim 7
Dependent Claim
24 words
A magnetic head according to claim 1, wherein said magnetic means provides a magnetoresistance effect in response to the transition of the magnetic flux.
Claim 8
Dependent Claim
34 words
A magnetic head according to claim 6, wherein said physical effect detecting means includes means for supplying an electric current to said magnetic means for detecting the magnetoresistance effect provided by said magnetic means.
Claim 9
Dependent Claim
29 words
A magnetic head according to claim 1, wherein said magnetic means comprises a layer made of material of high magnetic permeability and a coil provided adjacent to said layer,
Claim 10
Dependent Claim
150 words
A magnetic head for reading out information magnetically recorded on a magnetic recording medium in a waveform varying between two different phases, said head comprising: a block of high magnetic permeability disposed adjacent to and directly facing a surface of said magnetic recording medium to be read-out so as to provide a magnetic path for passing therethrough magnetic flux emanating from the magnetic record on said magnetic recording medium; magnetic means disposed adjacent to said block and extending parallel to the surface of said magnetic recording medium so as to cause the magnetic flux emanating from said magnetic record on said magnetic recording medium to pass therethrough, and responsive to transition of the magnetic flux corresponding to variation from one to the other phase in the waveform representing the recorded information to provide a predetermined physical effect; and means for detecting the predetermined physical effect provided by said magnetic means.
Claim 11
Dependent Claim
150 words
A magnetic head for reading out information magnetically recorded on a magnetic recording medium in a waveform varying between two different phases, said head comprising: a block of high magnetic permeability disposed adjacent to and directly facing a surface of said magnetic recording medium to be read-out so as to provide a magnetic path for passing therethrough magnetic flux emanating from the magnetic record on said magnetic recording medium; magnetic means disposed adjacent to said block and extending parallel to the surface of said magnetic recording medium so as to cause the magnetic flux emanating from said magnetic record on said magnetic recording medium to pass therethrough, and responsive to transition of the magnetic flux corresponding to variation from one to the other phase in the waveform representing the recorded information to provide a predetermined physical effect; and means for detecting the predetermined physical effect provided by said magnetic means.
Claim 12
Dependent Claim
23 words
A magnetic head according to claim 9, wherein said magnetic means provides magneto-optic effect in response to the transition of the magnetic flux.
Claim 13
Dependent Claim
15 words
A magnetic head according to claim 10, wherein said block is made of transparent material.
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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) | 1991-10-11 | 1992-04-11 | 1992-10-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-10-11 | 1996-04-11 | 1996-10-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-10-11 | 2000-04-11 | 2000-10-11 | $7700.00 | Window Closed / Lapsed |