Patent US4717979A successfully refreshed from Google Patents.
US4717979A
Expired / Lapsed
US
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Magnetic sensor device
Assignee: Canon Inc
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Filing: 1985-10-22
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Granted: 1988-01-05
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Expires: 2005-10-22
Abstract
Abstract A magnetic sensor device in which a plurality of magnetic resistive effect type elements for reading signals of respective reading channels recorded on a magnetic medium are biased by different magnetic fields from each other.
Inventors
- 👤 Koichi Washisu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 03:32
CPC Classifications
H; H03; H03M; H03M1/00; H03M1/12; H03M1/22; H03M1/24; H03M1/28; H03M1/285; G; G01; G01R; G01R33/00; G01R33/02; G01R33/06; G01R33/09
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
62 words
A magnetic sensor device for reading signals impressed in a plurality of channels on a recording medium comprising a plurality of magnetic resistive effect type elements arranged side by side in alignment with respective reading channels having respectively different magnetic intensities, and means for generating respective bias magnetic fields for each element to give different bias magnetic fields to said different elements.
Claim 2
Dependent Claim
62 words
A magnetic sensor device for reading signals impressed in a plurality of channels on a recording medium comprising a plurality of magnetic resistive effect type elements arranged side by side in alignment with respective reading channels having respectively different magnetic intensities, and means for generating respective bias magnetic fields for each element to give different bias magnetic fields to said different elements.
Claim 3
Dependent Claim
45 words
A magnetic sensor device according to claim 1, wherein said bias magnetic field generating means includes an electrically conductive line for generating the bias magnetic field, said line being arranged to vary its distance to said magnetic resistive effect type elements from element to element.
Claim 4
Dependent Claim
33 words
A magnetic sensor device according to claim 1, wherein said magnetic resistive effect type elements are divided into a plurality of groups, whereby the magnetic bias is made different from group to group.
Claim 5
Dependent Claim
45 words
A magnetic sensor device according to claim 3, wherein said bias magnetic field generating means includes an electrically conductive line for generating the bias magnetic field, said line being arranged to vary its distance to said magnetic resistive effect type elements from group to group.
Claim 6
Dependent Claim
72 words
A magnetic sensor drive for reading magnetically recorded information of a magnetic recording medium comprising a plurality of tracks having different intensities of magnetic fields, comprising: a plurality of magnetic resistive type elements for detecting magnetically recorded information of each one of said tracks; and means for impressing bias magnetic fields with different magnitudes to respective magnetic resistive type elements according to the intensity of the magnetic field of the respective track.
Claim 7
Dependent Claim
72 words
A magnetic sensor drive for reading magnetically recorded information of a magnetic recording medium comprising a plurality of tracks having different intensities of magnetic fields, comprising: a plurality of magnetic resistive type elements for detecting magnetically recorded information of each one of said tracks; and means for impressing bias magnetic fields with different magnitudes to respective magnetic resistive type elements according to the intensity of the magnetic field of the respective track.
Claim 8
Dependent Claim
39 words
A magnetic sensor device according to claim 5, wherein said plurality of tracks of the magnetic recording medium have magnetic recording signals with respectively different areas, whereby said magnetic field intensities of respective tracks are different from each other.
Claim 9
Dependent Claim
33 words
A magnetic sensor device according to claim 5, wherein said magnetic resistive effect type elements are divided into a plurality of groups, whereby the magnetic bias is made different from group to group.
Claim 10
Dependent Claim
43 words
A magnetic sensor device according to claim 5, wherein said bias magnetic means includes an electrically conductive line for impressing the bias magnetic field, said line being arranged to vary its distance to said magnetic resistive effect type elements from element to element.
References Cited (Backward Citations)
US4523243A
Cited
US4673998A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-01-04 | 1991-07-06 | 1992-01-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-01-04 | 1995-07-06 | 1996-01-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-01-04 | 1999-07-06 | 2000-01-05 | $7700.00 | Window Closed / Lapsed |