摘要 |
PURPOSE:To realize high-speed access on tracks without causing access errors by providing several nonrecording parts having low reflectivity disposed with intervals in the recording layer. CONSTITUTION:The optical recording medium 1 essentially consists of a disk- type glass substrate 3 the surface of which has concentrical rough areas 2, the recording layer 4 uniformly provided on the substrate, and a protective layer 5 uniformly provided on the recording layer 4 side of the substrate 3. The recording layer contains nonrecording parts 6 formed on rough surface parts 2' of the rough areas 2 and recording parts 7 formed on the flat area 2'' provided between the rough areas 2. As the intensity of reflected light from the nonrecording part 6 is weak compared to that of reflected light from the recording part 7 between the nonrecording parts 6, difference between the two reflected lights becomes large. Therefore, only the track-crossing signals with low output generated when a head crosses the nonrecording part 6 can be certainly extracted according to the difference of reflected lights. Thus, the access speed on tracks can be raised. |