| 摘要 |
An information recording medium (21) of the optical information reproduction device of the present invention includes a recording unit (3) capable of recording information three-dimensionally and provided with a track, and information is recorded by forming a plurality of recording marks along the track of the recording unit by a mark length recording method. When the track direction of the recording marks is assumed to be their longitudinal direction and the direction perpendicular to the track direction is assumed to be their lateral direction, with the present invention, for recording marks located substantially in the same plane, the total area of elongated recording marks, whose longitudinal length is greater than their lateral length, is greater than the total area of recording marks having other than elongated shapes. The optical information reproduction device of the present invention includes a first light source (20a) for emitting a reproduction light (22b) having a wavelength » 1 , an objective lens (6) for focusing the reproduction light on the recording unit, and a first photodetector (19a) for detecting a reproduction signal from the reflected light from the recording unit. The focused reproduction light includes as its main component a polarized light component that is polarized perpendicular to the track direction. Also, the recording unit has a track pitch of no more than 1.3 times the wavelength » 1 of the reproduction light.
|
