US4918681A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Data reproducing apparatus using idling current
Assignee: Toshiba Corp
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Filing: 1987-12-24
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Granted: 1990-04-17
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Expires: 2007-12-24
Abstract
Abstract A data reproducing apparatus is disclosed which permits stabilization of the light output of a light source, thereby to permit reliable reproduction of data. When recording data on an optical disk and also when reproducing the recorded data by illuminating the optical disk by means of a laser beam from a semiconductor laser, an idling current is supplied in advance to the semiconductor laser, to such an extent that the semiconductor laser does not emit a laser beam. As a result of the preliminary supply of the idling current, the output of the semiconductor laser is stabilized.
Inventors
- 👤 Hidetoshi Ikeda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 00:18
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/12; G11B7/125; G11B7/126; G11B7/004; H; H01; H01S; H01S5/00; H01S5/06; H01S5/068; H01S5/06825; H01S5/0683
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
102 words
A laser current control system in an optical reproducing memory system, comprising: an optical memory device in which data is recorded; means for generating a light beam to effect reproducing of the data recorded in said optical memory device; optical means for focusing the light beam onto said optical memory device while reproducing said data recorded in said optical memory device; and means for supplying a current to said generating means, said supplying means including first means for supplying an idling current insufficient to generate a light beam, and second means for supplying an operation current sufficient to generate a light beam.
Claim 2
Dependent Claim
102 words
A laser current control system in an optical reproducing memory system, comprising: an optical memory device in which data is recorded; means for generating a light beam to effect reproducing of the data recorded in said optical memory device; optical means for focusing the light beam onto said optical memory device while reproducing said data recorded in said optical memory device; and means for supplying a current to said generating means, said supplying means including first means for supplying an idling current insufficient to generate a light beam, and second means for supplying an operation current sufficient to generate a light beam.
Claim 3
Dependent Claim
32 words
An optical system according to claim 1, wherein said first means includes switch means and a transistor connected in series with said generating means, for controlling the supply of said idling current.
Claim 4
Dependent Claim
19 words
An optical system according to claim 1, wherein said means for generating a light beam is a semiconductor laser.
Claim 5
Dependent Claim
207 words
A laser current control system in an optical reproducing memory system, comprising: an optical memory device; means for generating a light beam to record data in said optical memory device and to reproduce data from said optical memory device; means for supplying a current to said generating means, said supplying means including first means for supplying an idling current insufficient to generate a light beam; optical means for focusing the light beam generated by said generating means onto said optical memory device while recording data in said optical memory device; first transistor means for controlling the idling current supplied from said first supplying means in order that the idling current not become sufficiently large to enable generating means to generate a light beam; second means for supplying an operation current sufficient to generate a light beam; second transistor means for controlling the current supplied from said second supplying means to enable said generating means to generate a light beam which is sufficient to reproduce data from said optical memory device; and third transistor means for controlling the current supplied from said second supplying means to enable said light beam generating means to generate a light beam which is sufficient to record data onto said optical memory device.
Claim 6
Dependent Claim
207 words
A laser current control system in an optical reproducing memory system, comprising: an optical memory device; means for generating a light beam to record data in said optical memory device and to reproduce data from said optical memory device; means for supplying a current to said generating means, said supplying means including first means for supplying an idling current insufficient to generate a light beam; optical means for focusing the light beam generated by said generating means onto said optical memory device while recording data in said optical memory device; first transistor means for controlling the idling current supplied from said first supplying means in order that the idling current not become sufficiently large to enable generating means to generate a light beam; second means for supplying an operation current sufficient to generate a light beam; second transistor means for controlling the current supplied from said second supplying means to enable said generating means to generate a light beam which is sufficient to reproduce data from said optical memory device; and third transistor means for controlling the current supplied from said second supplying means to enable said light beam generating means to generate a light beam which is sufficient to record data onto said optical memory device.
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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) | 1993-04-16 | 1993-10-16 | 1994-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-16 | 1997-10-16 | 1998-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-04-16 | 2001-10-16 | 2002-04-17 | $7700.00 | Window Closed / Lapsed |