US4241240A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical information recording apparatus
Assignee: Hitachi Ltd
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Filing: 1978-10-26
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Granted: 1980-12-23
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Expires: 1998-10-26
Abstract
Abstract An optical information recording and reproducing apparatus is disclosed in which a predetermined signal is recorded on a track of a rotating recording medium by a recording light beam and the recorded information is reproduced by a reproducing light beam. The information recorded on the last record track is reproduced by the recording beam and the reproducing beam and radiating position of the recording beam on the recording medium is displaced by a predetermined distance from the last record track.
Inventors
- 👤 Kazuo Shigematsu
- 👤 Keizo Kato
- 👤 Toshimitsu Miyauchi
- 👤 Seiji Yonezawa
- 👤 Fumiyuki Inose
- 👤 Kimio Tatsuno
- 👤 Takeshi Maeda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 08:50
CPC Classifications
G; G11; G11B; G11B17/00; G11B17/005; G11B27/00; G11B27/02; G11B7/00; G11B7/08; G11B7/09; G11B7/095; G11B7/0953
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
215 words
An optical information recording apparatus comprising: a first light source for emitting a recording beam; a second light source for emitting a reproducing beam; a recording medium having predetermined information recorded thereon; an optical system for directing said beams from said first and second light sources to said recording medium, said optical system being disposed between said first and second light sources and said recording medium; first reproducing means for reproducing information on said recording medium by said reproducing beam emitted from said second light source; means for zero-modulating said recording means emitted from said first light source; second reproducing means for reproducing information on said recording medium by said zero-modulation beam; first detecting means for detecting an address of said information reproduced by said first reproducing means; second detecting means for detecting an address of said information reproduced by said second reproducing means; means for making the addresses detected by said first and second detecting means to coincide with each other; and means for displacing said zero-modulation beam by a predetermined distance from the location of said reproduced information on said recording medium; whereby information carried on the beam emitted from said first light source is recorded on an adjacent track as the beam emitted from said second light source tracks the recorded information.
Claim 2
Dependent Claim
215 words
An optical information recording apparatus comprising: a first light source for emitting a recording beam; a second light source for emitting a reproducing beam; a recording medium having predetermined information recorded thereon; an optical system for directing said beams from said first and second light sources to said recording medium, said optical system being disposed between said first and second light sources and said recording medium; first reproducing means for reproducing information on said recording medium by said reproducing beam emitted from said second light source; means for zero-modulating said recording means emitted from said first light source; second reproducing means for reproducing information on said recording medium by said zero-modulation beam; first detecting means for detecting an address of said information reproduced by said first reproducing means; second detecting means for detecting an address of said information reproduced by said second reproducing means; means for making the addresses detected by said first and second detecting means to coincide with each other; and means for displacing said zero-modulation beam by a predetermined distance from the location of said reproduced information on said recording medium; whereby information carried on the beam emitted from said first light source is recorded on an adjacent track as the beam emitted from said second light source tracks the recorded information.
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) | 1983-12-23 | 1984-06-23 | 1984-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-23 | 1988-06-23 | 1988-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-23 | 1992-06-23 | 1992-12-23 | $7700.00 | Window Closed / Lapsed |