Optical disk apparatus

• Main Authors: YAMADA; SHIN-ICHI, EDAHIRO; YASUAKI, WATANABE; KATSUYA, MORIYA; MITSUROU, TAKAMINE; KOUICHI
• Format: Patent
• Language: English
• Published: 14.11.2000
• Edition: 7
• Subjects: INFORMATION STORAGE; INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORDCARRIER AND TRANSDUCER; PHYSICS

An optical disk apparatus comprising means for moving a focal point of a light beam for reproducing information recorded on an information face of a disk, in the direction perpendicular to the information face; means for detecting a reflected light from the disk; and means for discriminating whether the disk set in the apparatus is a disk having a thick base substrate or a disk having a thin base substrate. In this apparatus, a maximum value AS1Lmax of an output signal from the reflected light detecting means and a maximum value ENVmax of an amplitude of an information reproducing signal are detected while driving the focal point moving means so that the focal point passes through the information face, and the discriminating means discriminates whether the disk set in the apparatus is a disk having a thick base substrate or a disk having a thin base substrate, on the basis of the ratio of ENVmax to AS1Lmax. Therefore, it is possible to discriminate between a DVD having a thin base substrate and a CD having a thick base substrate.