Patent US4562502A successfully refreshed from Google Patents.
US4562502A
Expired / Lapsed
US
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Optical reproducing system
Assignee: TDK Corp
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Filing: 1983-04-20
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Granted: 1985-12-31
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Expires: 2003-04-20
Abstract
Abstract An optical reproducing system for reading out magnetically recorded data comprises an optical head (4,4a,4b,4c,4d) for copying magnetic pattern on a magnetic recording medium like a magnetic tape (1), a conversion system (5,6,7,8,9,10) for converting a magnetic pattern on the optical head (4 et al.) to an optical pattern by using the Faraday effect which rotates a polarization of an LED beam (light emission diode) or a laser beam according to magnetic polarity in a domain in said optical head, a charge coupled device (3, CCD) with a plurality of cells for converting beam energy polarized according to recorded data to correspond to electrical output signal. The CCD device effects the conversion or reading of a plurality of data simultaneously.
Inventors
- 👤 Joichiro Ezaki
- 👤 Hiroshi Kanai
- 👤 Yoshimi Kitahara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 05:28
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
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
94 words
An optical reproducing system for reading out magnetically stored information comprising; (a) an optical head for obtaining magnetic copy in a magnetic pattern of data magnetically recorded on an area of a recording medium which contacts said optical head and moves relative to said optical head, (b) conversion means for converting said magnetic pattern to an optical pattern, (c) a reception means for receiving said optical pattern to convert said optical pattern to an electrical signal, (d) said reception means converting said optical pattern with a plurality of data to said electrical signal simultaneously.
Claim 2
Dependent Claim
94 words
An optical reproducing system for reading out magnetically stored information comprising; (a) an optical head for obtaining magnetic copy in a magnetic pattern of data magnetically recorded on an area of a recording medium which contacts said optical head and moves relative to said optical head, (b) conversion means for converting said magnetic pattern to an optical pattern, (c) a reception means for receiving said optical pattern to convert said optical pattern to an electrical signal, (d) said reception means converting said optical pattern with a plurality of data to said electrical signal simultaneously.
Claim 3
Dependent Claim
19 words
An optical reproducing system according to claim 1, wherein said reception means has a two dimensional array of photo-transistors.
Claim 4
Dependent Claim
73 words
An optical reproducing system according to claim 1, wherein said optical head comprises a substrate (4a), a soft magnetic film (4b) attached on said substrate (4a), a reflection film (4c) attached on said soft magnetic film (4b), and said soft magnetic film (4b) takes a copy of magnetically recorded pattern on a recording medium to effect a rotation of polarization plane of a beam which illuminates the recording medium according to recorded data.
Claim 5
Dependent Claim
82 words
An optical reproducing system according to claim 1, wherein said conversion means comprises an optical source for generating an optical beam, a polarizer for polarizaing linearly said optical beam, a beam splitter for offsetting an output beam of said polarizer to illuminate said optical head with an output beam of said polarizer and passing through a beam reflected by said optical head, and an analyzer arranged at an output of said beam splitter to detect a polarized beam according to recorded data.
Claim 6
Dependent Claim
16 words
An optical reproducing according to claim 4, wherein said optical source is a He-Ne laser source.
Claim 7
Dependent Claim
16 words
An optical reproducing system according to claim 4, wherein said optical source is an LED source.
Claim 8
Dependent Claim
29 words
An optical reproducing system according to claim 4, wherein said optical beam has some cross section enough for illuminating a plurality of magnetic cells on a recording medium simultaneously.
Claim 9
Dependent Claim
17 words
An optical reproducing system according to claim 1 wherein said reception means is a charge coupled device.
Claim 10
Dependent Claim
28 words
An optical reproducing system according to claim 8, wherein said electrical signal in said charge coupled device is transferred in synchronization with the movement of the recording medium.
Claim 11
Dependent Claim
30 words
An optical reproducing system according to claim 9, wherein a line of signal in said charge coupled device is transferred in synchronization a line of movment of said recording medium.
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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) | 1988-12-30 | 1989-07-01 | 1989-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-12-30 | 1993-07-01 | 1993-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-12-30 | 1997-07-01 | 1997-12-31 | $7700.00 | Window Closed / Lapsed |