Optical disc drive, optical storage medium, optical storage medium inspection apparatus, and optical storage medium inspection method

Abstract

An optical disc drive having an optical pickup head emitting a light beam to an optical storage medium, detecting the light beam reflected from the optical storage medium, and outputting a signal based on the received reflected light, having a jitter measuring unit measuring jitter in signals output from the optical pickup head and having an evaluation unit determining from the measured jitter if the optical storage medium is good or defective. The jitter measuring unit measures jitter in a train of 3T or longer marks or spaces from an optical storage medium to which digital information is recorded as a train of marks or spaces of length kT based on a period T and an integer k of two or more.

1 - 75 . (canceled) 
     
     
         76 . An optical storage medium comprising:
 a first recording layer as recording layers for recording information, wherein the first recording layer is a read-only recording layer; and   a second recording layer as recording layers for recording information, wherein the second recording layer is a recording layer enabling recording data only once, wherein the first recording layer is disposed closer to the light incidence side of the medium than the second recording layer,   whereby information is recorded or reproduced by exposure to a light beam.   
     
     
         77 . An optical storage medium comprising:
 a first recording layer as recording layers for recording information, wherein the first recording layer is a read-only recording layer; and   a second recording layer as recording layers for recording information, wherein the second recording layer is a recording layer enabling repeatedly recording and erasing data, wherein the first recording layer is disposed closer to the light incidence side of the medium than the second recording layer,   whereby information is recorded or reproduced by exposure to a light beam.   
     
     
         78 . An optical storage medium including multiple tracks formed concentrically or in a spiral for recording information using marks and spaces between the marks by emitting a light beam to the recording surface of the tracks, wherein a signal not including edges adjacent to the shortest marks and/or the shortest spaces denotes a first playback signal quality.