Login| Sign Up| Help| Contact|

Patent Searching and Data

Document Type and Number:
Japanese Patent JP3361079
Kind Code:
PROBLEM TO BE SOLVED: To increase linear recording density and to increase recording capacity of a medium by forming a prescribed relation among the shortest pit interval along a scan direction of a read-out light beam, the wavelength of the read-out light beam and a numerical aperture of an objective lens. SOLUTION: An optical recording medium forming a phase pit according to a signal and changing a reflectance according to a temperature is irradiated by the read-out light beam, and the phase pit is read while partially changing the reflectance in the scan spot of the read-out light beam. In such a optical recording medium, the shortest phase pit interval of a recording signal along the scan direction of the read-out light beam is made λ/2NA or below when the wavelength of the read-out light beam is defined λ, the numerical aperture of the objective lens is NA. By such a optical recording medium, recording density in the scan direction of the light beam of a laser beam, etc., that is, the linear recording density, is increased by making a pit arrangement interval (recording pit interval) in this direction λ/2NA or below.

Atsushi Fukumoto
Toshiki Udagawa
Shunji Yoshimura
Masumi Ono
Koichi Yasuda
Application Number:
Publication Date:
January 07, 2003
Filing Date:
August 30, 1999
Export Citation:
Click for automatic bibliography generation   Help
International Classes:
G11B7/007; G11B7/24; G11B7/24085; (IPC1-7): G11B7/24; G11B7/007; G11B7/24
Domestic Patent References:
Other References:
Attorney, Agent or Firm:
Akira Koike (2 outside)