Patent US4901303A successfully refreshed from Google Patents.
US4901303A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photo-electro-magnetic disc device
Assignee: Pioneer Corp
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Filing: 1988-08-01
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Granted: 1990-02-13
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Expires: 2008-08-01
Abstract
Abstract A photo-electro-magnetic disc device has a photo-electro-magnetic disc accommodated in a disc cartridge load as a unit into cartridge holder loaded in the disc device. The cartridge holder with the end of a loading mechanism moves the disc onto a turn table. An optical head and a magnetic field applying part for recording data are loaded facing opposite sides of the disc. Magnetic members are provided on the same side of the disc as is the optical head and are connected to the cartridge holder which is made of magnetic material as to confront magnetic field applying part through the disc. A magnetic circuit which includes the disc is thus formed whereby the magnetic flux from the magnetic field applying part passes through the disc thereby providing a high magnetic field strength throughout the entire region of the disc to be irradiated by a light spot from the optical head.
Inventors
- 👤 Ikuya Kikuchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:29
CPC Classifications
G; G11; G11B; G11B17/00; G11B17/02; G11B17/04; G11B17/041; G11B11/00; G11B11/10; G11B11/105; G11B11/1055
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
138 words
A photo-electro-magnetic disc device comprising: a cartridge holder adapted to hold a disc cartridge containing a photo-electro-magnetic disc, loaded therein, and to place said photo-electro-magnetic disc on a turn table; an optical head for applying a light spot to said photo-electro-magnetic disc placed on said turn table; and magnetic field applying means, arranged on one side of said photo-electro-magnetic disc on the other side of which said optical head is provided, for applying a magnetic field in a predetermined direction to the part of said photo-electro-magnetic disc which is irradiated by said light spot, the improvement comprising: magnetic members arranged as to confront said magnetic field applying means through said photo-electromagnetic disc, wherein; said cartridge holder is made of magnetic material, and said magnetic members are magnetically coupled to said magnetic field applying means through said cartridge holder.
Claim 2
Dependent Claim
138 words
A photo-electro-magnetic disc device comprising: a cartridge holder adapted to hold a disc cartridge containing a photo-electro-magnetic disc, loaded therein, and to place said photo-electro-magnetic disc on a turn table; an optical head for applying a light spot to said photo-electro-magnetic disc placed on said turn table; and magnetic field applying means, arranged on one side of said photo-electro-magnetic disc on the other side of which said optical head is provided, for applying a magnetic field in a predetermined direction to the part of said photo-electro-magnetic disc which is irradiated by said light spot, the improvement comprising: magnetic members arranged as to confront said magnetic field applying means through said photo-electromagnetic disc, wherein; said cartridge holder is made of magnetic material, and said magnetic members are magnetically coupled to said magnetic field applying means through said cartridge holder.
Claim 3
Dependent Claim
20 words
A photo-electro-magnetic disc device in claim 1, wherein said magnetic members are integral with said cartridge holder of magnetic material.
Claim 4
Dependent Claim
166 words
A photo-electro-magnetic disc device comprising: a cartridge holder adapted to hold a disc cartridge containing a photo-electro-magnetic disc, loaded therein, and to place said photo-electro-magnetic disc on a turn table; an optical head for applying light spot to said photo-electro-magnetic disc placed on said turn table; magnetic field applying means magnetically coupled to said cartridge holder and arranged on one side of said photo-electro-magnetic disc on the other side of which said optical head is provided, for applying magnetic field in a predetermined direction to the part of said photo-electro-magnetic disc which is irradiated by said light spot, the improvement comprises: said cartridge holder comprising a magnetic material, and magnetic members, magnetically coupled to said cartridge holder and confronting said magnetic field applying means through said disc; whereby a magnetic circuit is formed which includes said disc such that magnetic flux from said magnetic field applying means extends therefrom through said disc, said magnetic members, said cartridge holder and back to said magnetic field applying means.
Claim 5
Dependent Claim
166 words
A photo-electro-magnetic disc device comprising: a cartridge holder adapted to hold a disc cartridge containing a photo-electro-magnetic disc, loaded therein, and to place said photo-electro-magnetic disc on a turn table; an optical head for applying light spot to said photo-electro-magnetic disc placed on said turn table; magnetic field applying means magnetically coupled to said cartridge holder and arranged on one side of said photo-electro-magnetic disc on the other side of which said optical head is provided, for applying magnetic field in a predetermined direction to the part of said photo-electro-magnetic disc which is irradiated by said light spot, the improvement comprises: said cartridge holder comprising a magnetic material, and magnetic members, magnetically coupled to said cartridge holder and confronting said magnetic field applying means through said disc; whereby a magnetic circuit is formed which includes said disc such that magnetic flux from said magnetic field applying means extends therefrom through said disc, said magnetic members, said cartridge holder and back to said magnetic field applying means.
Claim 6
Dependent Claim
20 words
The photo-electro-magnetic disc device of claim 3 wherein said magnetic members are extensions of and integral with said cartridge holder.
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) | 1993-02-12 | 1993-08-14 | 1994-02-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-02-12 | 1997-08-14 | 1998-02-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-02-12 | 2001-08-14 | 2002-02-13 | $7700.00 | Window Closed / Lapsed |