Optical information storage unit having phase compensation means for applying different phase compensation quantities with respect to signals detected from land and groove of recording medium

摘要

An optical information storage unit irradiates a light on a recording medium having a recording surface provided with a land and a groove and detects a reproduced signal from a light reflected from the recording medium. The optical information storage unit is provided with a phase compensation mechanism, provided in an optical path through which the light irradiated on the recording medium and a reflected light from the recording medium passes, for applying with respect to the reflected light a first phase compensation quantity required to detect a signal from the land and a second phase compensation quantity required to detect a signal from the groove.