Patent US4771413A successfully refreshed from Google Patents.
US4771413A
Expired / Lapsed
US
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Optical recording and reproducing apparatus
Assignee: Toshiba Corp
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Filing: 1987-04-13
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Granted: 1988-09-13
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Expires: 2007-04-13
Abstract
Abstract An optical recording and reproducing apparatus with a first light source for generating a recording laser beam, a second light source for generating a reproducing beam which has shorter wavelength than that of the recording laser beam. Information is recorded by forming pits on a recording member by the recording laser beam, and reproduced by directing the reproducing laser beam onto the pits and obtaining the beam reflected beam from the pits.
Inventors
- 👤 Chiaki Nago
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 09:21
CPC Classifications
G; G11; G11B; G11B20/00; G11B20/10; G11B20/10009; G11B7/00; G11B7/004; G11B7/08; G11B7/12
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
184 words
An optical recording and reproducing system comprising: first light source means for generating a recording laser beam having a first wavelength and having a first diameter; second light source means for generating a reproducing laser beam which has a second wavelength of a shorter wavelength than said first wavelength of said first light source means, said reproducing laser beam having a second diameter smaller than said first diameter; a recording member having a substrate, a reflective layer, and a recording layer which is less reflective than said reflective layer, overlying said reflective layer; optical means for directing said recording laser beam from said first light source means onto said recording member to form a recorded area by rendering transparent a spot of said recording layer having said fixed diameter, and for directing said beam of said second diameter from said second light source means on to said recording member and obtaining a reflection beam from said recording member; and reproducing means for converting said reflection beam to a signal indicative thereof, to reproduce the information on said recording member according to said reflection signal.
Claim 2
Dependent Claim
184 words
An optical recording and reproducing system comprising: first light source means for generating a recording laser beam having a first wavelength and having a first diameter; second light source means for generating a reproducing laser beam which has a second wavelength of a shorter wavelength than said first wavelength of said first light source means, said reproducing laser beam having a second diameter smaller than said first diameter; a recording member having a substrate, a reflective layer, and a recording layer which is less reflective than said reflective layer, overlying said reflective layer; optical means for directing said recording laser beam from said first light source means onto said recording member to form a recorded area by rendering transparent a spot of said recording layer having said fixed diameter, and for directing said beam of said second diameter from said second light source means on to said recording member and obtaining a reflection beam from said recording member; and reproducing means for converting said reflection beam to a signal indicative thereof, to reproduce the information on said recording member according to said reflection signal.
Claim 3
Dependent Claim
27 words
An optical recording and reproducing apparatus according to claim 1, further including a housing for mounting said first light source means and said second light source means.
Claim 4
Dependent Claim
50 words
An optical recording and reproducing apparatus according to claim 1, wherein said optical means directs the laser beam from said second light source to a position forward along the data recording direction on the recording member from the position where the laser beam from said first light source is directed.
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) | 1991-09-13 | 1992-03-14 | 1992-09-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-09-13 | 1996-03-14 | 1996-09-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-09-13 | 2000-03-14 | 2000-09-13 | $7700.00 | Window Closed / Lapsed |