Title:
MEDIUM FOR OPTICAL RECORDING AND APPARATUS FOR OPTICAL INFORMATION PROCESSING
Document Type and Number:
WIPO Patent Application WO2004074908
Kind Code:
A3
Abstract:
A medium for optical recording is disclosed, from which recorded information is reproduced by a laser beam. The medium includes a disk board having a recording surface, and multiple pits in the recording surface. The pits are included in cells having equal size and varying pit-occupancy rates dependent on the recording information, the pit-occupancy rate being the ratio of area of the pit to area of the corresponding cell. The depths H of the pits, the wavelength lambda of the laser beam, and the refractive index n of the board are related as, lambda /6n < H < lambda /4n.
Inventors:
HIRAI HIDEAKI (JP)
Application Number:
PCT/JP2004/002046
Publication Date:
January 27, 2005
Filing Date:
February 20, 2004
Export Citation:
Assignee:
RICOH KK (JP)
HIRAI HIDEAKI (JP)
HIRAI HIDEAKI (JP)
International Classes:
G11B7/24; G11B7/007; G11B7/013; G11B7/09; G11B7/13; G11B7/135; G02F; (IPC1-7): G11B7/007; G11B7/24
Foreign References:
| US5757763A | 1998-05-26 | |||
| US6175548B1 | 2001-01-16 | |||
| EP1197963A2 | 2002-04-17 |
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