PURPOSE: To obtain the apparatus, which can perform stable reproduction, even for an optical disk, which can reproduce high-density phase pitch information higher than the reading limit caused by the wavelength of a light source and the aperture of an objective lens.
CONSTITUTION: Two secondary luminous fluxes 4b and 4c on the surface of an optical disk are arranged so that the luminous fluxes are offset by 1/2 track pitch or more, e.g. 5/4 or 9/4 track pitch with respect to a main luminous flux 4a. A servo signal is generated from the luminous fluxes. The output power of a laser is switched in response to the kind or the operating mode of the optical disk. Thus, the stable detection of the servo signal can be performed, and the life of the optical disk can be elongated.
INOUE MASAYUKI
TANAKA HISAMITSU
NAKAJIMA JUNJI
SUZUKI MOTOYUKI
FUKUI YUKIO
