Optical disk device configured to reliably reproduce address information

摘要

An optical disk device which reproduces address information embossed and formed on an optical disk. Return light of laser light is detected by a photodetector which is split into at least two components along the radial direction and signals representing the return light are output. Address information is reproduced by selectively switching between a summation signal and a difference signal between two signals. When there is a focus deviation, the summation signal of two signals is used to reproduce the address information and when the optical disk is tilted, the difference signal of two signals is used to reproduce the address information.