Title:
OPTICAL INFORMATION RECORDING DEVICE AND OPTICAL INFORMATION RECORDING MEDIUM
Document Type and Number:
Japanese Patent JP3205050
Kind Code:
B2
Abstract:
PURPOSE: To provide an optical information recording device which enables recording and reproducing or either of them for plural laser beams having different wavelength, especially enables upward compatible system which overwrite-records phase variation media for long wavelength with short wavelength recording and reproducing drive.
CONSTITUTION: This device is provided with a means 31 which discriminates whether a signal recorded in media is recorded with long wavelength low NA or recorded with short wavelength high NA, and a means 13 which restricts a laser beam, a lens, and numerical aperture of the lens. And when a signal recorded with long wavelength low NA is overwritten, recording is performed with a condition in which it becomes equivalent wavelength/NA ratio by restricting numerical aperture of a lens.
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Inventors:
Nobuo Akahira
Noboru Yamada
Kenichi Nagata
Noboru Yamada
Kenichi Nagata
Application Number:
JP15464892A
Publication Date:
September 04, 2001
Filing Date:
June 15, 1992
Export Citation:
Assignee:
Matsushita Electric Industrial Co., Ltd
International Classes:
G11B7/00; G11B7/004; G11B7/0045; G11B7/006; G11B7/135; G11B7/24; G11B7/30; (IPC1-7): G11B7/24; G11B7/004; G11B7/006
Domestic Patent References:
| JP3250451A | ||||
| JP643833A | ||||
| JP61174026U |
Attorney, Agent or Firm:
Fumio Iwahashi (2 others)
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