US4340914A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermomagnetic recording and reproducing apparatus
Assignee: Olympus Corp
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Filing: 1980-03-24
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Granted: 1982-07-20
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Expires: 2000-03-24
Abstract
Abstract A heat magnetic recording and reproducing apparatus is disclosed. The apparatus comprises a record medium running in a predetermined direction, a means for generating a laser light beam for locally heating the medium, a magnetic field generating device for generating a magnetic field at the heated portion, an information recording means provided in opposition to the magnetic field generating device and having an auxiliary magnetic pole piece for focusing a magnetic flux from the magnetic field generating device into at least the heated portion, a means provided at a front stage of the information recording means to the running of the medium for generating a laser light beam for locally heating the medium, a magnetic field generating device for generating a magnetic field at the heated portion, and an information erasing means having an auxiliary magnetic pole piece for focusing a magnetic flux from the magnetic field generating device into the heated portion.
Inventors
- 👤 Naohiro Hanaoka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:19
CPC Classifications
G; G11; G11B; G11B11/00; G11B11/10; G11B11/105; G11B11/1055; G11B11/10552; G11B11/10554; G11B11/10502; G11B11/10504; G11B11/10508; G11B11/10532; G11B11/10534; G11B11/10536; G11B5/00; G11B5/127; G11B5/1278; G11B2005/0002; G11B2005/0005; G11B2005/0021
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
153 words
A thermomagnetic recording and reproducing apparatus comprising a record medium running in a predetermined direction, first light generating means for generating a laser light beam for locally heating the medium, a first magnetic field generating device for generating a magnetic field at the heated portion, information recording means provided in opposition to the magnetic field generating device and having a first auxiliary magnetic pole piece for focusing first magnetic flux from the magnetic field generating device into at least the heated portion, second light generating means adjacent the information recording means upstream of the running of the medium for generating a second laser light beam for locally heating the medium, a second magnetic field generating device for generating a second magnetic field at the heated portion, and information erasing means having a second auxiliary magnetic pole piece for focusing a second magnetic flux from the magnetic field generating device into the heated portion.
Claim 2
Dependent Claim
153 words
A thermomagnetic recording and reproducing apparatus comprising a record medium running in a predetermined direction, first light generating means for generating a laser light beam for locally heating the medium, a first magnetic field generating device for generating a magnetic field at the heated portion, information recording means provided in opposition to the magnetic field generating device and having a first auxiliary magnetic pole piece for focusing first magnetic flux from the magnetic field generating device into at least the heated portion, second light generating means adjacent the information recording means upstream of the running of the medium for generating a second laser light beam for locally heating the medium, a second magnetic field generating device for generating a second magnetic field at the heated portion, and information erasing means having a second auxiliary magnetic pole piece for focusing a second magnetic flux from the magnetic field generating device into the heated portion.
Claim 3
Dependent Claim
54 words
A thermomagnetic recording and reproducing apparatus as in claim 1, wherein the information recording means decreases the coercive force of the heated portion of the medium so as to record predetermined information on the medium by a magnetic field in accordance with signals to be recorded and generated by the magnetic field generating device.
Claim 4
Dependent Claim
44 words
A thermomagnetic recording and reproducing apparatus as in claim 1, wherein the information recording means generates a biasing magnetic field from the magnetic field generating device and records predetermined information on the medium by a laser light beam modulated by signals to be recorded.
Claim 5
Dependent Claim
45 words
A thermomagnetic recording and reproducing apparatus as in claim 1, wherein the information erasing means forms a spot diameter on the medium with the laser light beam larger than the spot diameter on the medium with the laser light beam of the information recording means.
Claim 6
Dependent Claim
69 words
A thermomagnetic recording and reproducing apparatus as in claim 1, wherein said first and second auxiliary magnetic pole pieces includes a pair of non-magnetic members, a ferromagnetic film sandwiched between said members, and a ferromagnetic body larger than said ferromagnetic film, said auxiliary pole piece being positioned to place said ferromagnetic film transverse to the recording medium and transverse to the direction of the travel of the recording medium.
Claim 7
Dependent Claim
66 words
An apparatus as in claim 1, wherein said first and second auxiliary magnetic pole pieces each include a ferromagnetic film, means for mounting said ferromagnetic film transverse to the direction of the medium and transverse to the direction of the movement of the medium, and a ferromagnetic body larger than the ferromagnetic film and positioned to be further away from the medium than said magnetic film.
Claim 8
Dependent Claim
18 words
An apparatus as in claim 6, wherein said means for mounting said ferromagnetic film includes a non-magnetic member.
Claim 9
Dependent Claim
23 words
An apparatus as in claim 5, 6, or 7, wherein one of said auxiliary pole pieces includes a winding around said ferromagnetic body.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-07-19 | 1986-01-18 | 1986-07-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-07-19 | 1990-01-18 | 1990-07-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-07-19 | 1994-01-18 | 1994-07-20 | $7700.00 | Window Closed / Lapsed |