Patent US5287334A successfully refreshed from Google Patents.
US5287334A
Expired / Lapsed
US
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Magneto-optical pickup apparatus and magneto-optical recording/reproducing apparatus
Assignee: Sony Corp
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Filing: 1991-12-11
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Granted: 1994-02-15
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Expires: 2011-12-11
Abstract
Abstract A magneto-optical pickup apparatus includes an objective lens for focusing a laser beam emitted from a laser device onto a magneto-optical recording medium, driving coils, on which the objective lens is mounted, for driving the objective lens in focusing and tracking directions, and a plate arranged at an end portion of the driving coils between the objective lens and the magneto-optical recording medium. The plate is formed with a coil pattern for generating a magnetic field to be applied to the magneto-optical recording medium, and can allow a laser beam transmitted through the objective lens to pass therethrough.
Inventors
- 👤 Kietsu Iwabuchi
- 👤 Koji Sasaki
- 👤 Tetsu Watanabe
- 👤 Tamotsu Yamagami
- 👤 Yoshio Aoki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 22:24
CPC Classifications
G; G11; G11B; G11B11/00; G11B11/10; G11B11/105; G11B11/10582; G11B11/10584; G11B11/10532; G11B11/10534; G11B11/10536; G11B11/1055; G11B11/10552; G11B11/10554
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
105 words
A magneto-optical pickup apparatus for recording or reproducing data on a magneto-optical recording medium, for use with a laser beam emission means, comprising: laser beam focusing means for focusing a laser beam emitted from the laser beam emission means onto the magneto-optical recording medium; and magnetic field generating means, arranged adjacent to the laser beam focusing means, for generating a magnetic field to be applied to the magneto-optical recording medium, including a plate made of a material having light transmission characteristics through which the laser beam can pass, and a flat coil pattern, formed on one surface of the plate, for generating the magnetic field.
Claim 2
Dependent Claim
105 words
A magneto-optical pickup apparatus for recording or reproducing data on a magneto-optical recording medium, for use with a laser beam emission means, comprising: laser beam focusing means for focusing a laser beam emitted from the laser beam emission means onto the magneto-optical recording medium; and magnetic field generating means, arranged adjacent to the laser beam focusing means, for generating a magnetic field to be applied to the magneto-optical recording medium, including a plate made of a material having light transmission characteristics through which the laser beam can pass, and a flat coil pattern, formed on one surface of the plate, for generating the magnetic field.
Claim 3
Dependent Claim
33 words
A magneto-optical pickup apparatus according to claim 1, wherein the laser beam is focused by the laser beam focusing means substantially on the center of the magnetic field generated by the coil pattern.
Claim 4
Dependent Claim
28 words
A magneto-optical pickup apparatus according to claim 2, wherein the coil pattern is formed on the surface of the plate which is closest to said magneto-optical recording medium.
Claim 5
Dependent Claim
24 words
A magnetic-optical pickup apparatus according to claim 1, wherein the plate is arranged between the laser beam focusing means and the magneto-optical recording medium.
Claim 6
Dependent Claim
33 words
A magneto-optical pickup apparatus according to claim 1, wherein the laser beam is focused by the laser beam focusing means substantially on the center of the magnetic field generated by the coil pattern.
Claim 7
Dependent Claim
24 words
A magneto-optical pickup apparatus according to claim 1, wherein the plate is arranged between the laser beam focusing means and the magneto-optical recording medium.
Claim 8
Dependent Claim
37 words
A magneto-optical recording/reproducing apparatus according to claim 1, wherein the magneto-optical recording medium has recording surfaces on two opposing surfaces and two of said magneto-optical pickup apparatuses are arranged on opposite sides of the magneto-optical recording medium.
Claim 9
Dependent Claim
40 words
A magneto-optical recording/reproducing apparatus according to claim 7, wherein the two magneto-optical pickup apparatuses arranged on opposite sides of the magneto-optical recording medium are simultaneously operated to simultaneously perform recording/reproduction on the two recording surfaces of the magneto-optical recording medium.
Claim 10
Dependent Claim
97 words
A magneto-optical pickup apparatus for recording or reproducing data on a magneto-optical recording medium, for use with a laser beam emission means, comprising: laser beam focusing means for focusing a laser beam emitted form the laser beam emission means onto the magneto-optical recording medium; and magnetic field generating means, arranged adjacent to the laser beam focusing means, for generating a magnetic field to be applied to the magneto-optical recording medium, including a plate of a light-transmitting material through which the laser beam can pass, and a coil pattern, formed on the plate, for generating the magnetic field.
Claim 11
Dependent Claim
97 words
A magneto-optical pickup apparatus for recording or reproducing data on a magneto-optical recording medium, for use with a laser beam emission means, comprising: laser beam focusing means for focusing a laser beam emitted form the laser beam emission means onto the magneto-optical recording medium; and magnetic field generating means, arranged adjacent to the laser beam focusing means, for generating a magnetic field to be applied to the magneto-optical recording medium, including a plate of a light-transmitting material through which the laser beam can pass, and a coil pattern, formed on the plate, for generating the magnetic field.
Claim 12
Dependent Claim
18 words
A magneto-optical pickup apparatus according to claim 9, wherein the light-transmitting material of the plate is optical glass.
Claim 13
Dependent Claim
33 words
A magneto-optical pickup apparatus according to claim 9, wherein the laser beam is focused by the laser beam focusing means substantially on the center of the magnetic field generated by the coil pattern.
Claim 14
Dependent Claim
28 words
A magneto-optical pickup apparatus according to claim 10, wherein the coil pattern is formed on the surface of the plate which is closest to said magneto-optical recording medium.
Claim 15
Dependent Claim
16 words
A magneto-optical pickup apparatus according to claim 1, wherein the coil pattern is a printed coil.
Claim 16
Dependent Claim
17 words
A magneto-optical pickup apparatus according to claim 1, wherein the coil pattern is a thin film coil.
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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) | 1997-02-14 | 1997-08-16 | 1998-02-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-02-14 | 2001-08-16 | 2002-02-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-02-14 | 2005-08-16 | 2006-02-15 | $7700.00 | Window Closed / Lapsed |