EP0106673A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Optical and reversible recording and reproducing apparatus
Assignee: Panasonic Holdings Corp
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Filing: 1983-10-13
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Granted: —
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Expires: 2003-10-13
Abstract
Abstract This invention relates to an optical and reversible recording and reproducing apparatus and intends to provide a practical apparatus in which information signals can be recorded, reproduced and erased by irradiating a laser beam and the like on the substrate to be optically recorded. More practically, there is provided such an apparatus wherein two light sources such as lasers having different wavelengths are used, and a first almost circular micro-lightspot is produced by one light source, while a second elliptic lightspot having a longitudinal diameter in the tangential direction of a guide track on a disc is produced by the other light source. These first and second lightspots are closely irradiated on the same guid track of an optical recording disc. The recording and reproducing of the signals are performed using the first lightspot while the erasion of the recorded signals can be made by using the second lightspot or cooperatively using the first and second lightspots.
Inventors
- 👤 Tomio Yoshida
- 👤 Isao Satoh
- 👤 Shunji Ohara
- 👤 Kenji Koishi
- 👤 Yuzuru Kuroki
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 10:20
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/12; G11B7/125; G11B7/004; G11B7/0055; G11B7/00557; G11B7/007; G11B7/00745; G11B7/08
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
188 words
1 . An apparatus for optically and reversibly recording and reproducing signals by applying micro- lightspots on an optical recording medium which uses, as a thin recording film, an optical recording material which can reversibly change its optical characteristic by irradiation by light on said thin film formed on a substrate having optical guide tracks, said apparatus comprising: two light source means for respectively applying light beams having different wave lengths; and optical means for respectively coverging the applied light beams by same optical diaphragm means and for closely arranging one light beam as a first substantially circular micro-lightspot and the other light beam as a second elliptic lightspot having a longitudinal diameter in the tangential direction of said optical guide track on said same optical guide track, wherein a condition for temperature elevation and rapid cooling is provided for said optical recording medium by said first almost circular lightspot, and a condition for temperature elevation and slow cooling is provided for said optical recording medium by said second elliptic light spot solely or by said second elliptic light spot and said first almost circular light spot cooperatively.
Claim 2
Dependent Claim
188 words
1 . An apparatus for optically and reversibly recording and reproducing signals by applying micro- lightspots on an optical recording medium which uses, as a thin recording film, an optical recording material which can reversibly change its optical characteristic by irradiation by light on said thin film formed on a substrate having optical guide tracks, said apparatus comprising: two light source means for respectively applying light beams having different wave lengths; and optical means for respectively coverging the applied light beams by same optical diaphragm means and for closely arranging one light beam as a first substantially circular micro-lightspot and the other light beam as a second elliptic lightspot having a longitudinal diameter in the tangential direction of said optical guide track on said same optical guide track, wherein a condition for temperature elevation and rapid cooling is provided for said optical recording medium by said first almost circular lightspot, and a condition for temperature elevation and slow cooling is provided for said optical recording medium by said second elliptic light spot solely or by said second elliptic light spot and said first almost circular light spot cooperatively.
Claim 3
Dependent Claim
61 words
An optical and reversible recording and reproducing apparatus according to claim 1, wherein signals are recorded on and reproduced from said optical recording medium by said first substantially circular light spot, and wherein the signals recorded on said medium are erased by said second elliptic light spot solely or by said elliptic light spot and said almost circular light spot cooperatively.
Claim 4
Dependent Claim
40 words
An optical and reversible recording and reproducing apparatus according to claim 1 or claim 2, wherein servo signals necessary to record and reproduce signals on and from said optical recording medium are obtained by said first almost circular light spot.
Claim 5
Dependent Claim
67 words
An optical and reversible recording and reproducing apparatus according to any preceding claim, further comprising means for fixing an interval to be erased on said optical recording disc on the basis of the signals reproduced from said.optical recording disc by said first almost circular lightspot, and means for generating and applying an erasing light for a necessary period of time on the basis of said fixed signal.
Claim 6
Dependent Claim
24 words
An optical and reversible recording and reproducing apparatus according to any preceding claim, wherein said two light source means are laser light source means.
References Cited (Backward Citations)
No citation records indexed.
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