Optical device including a calibrating unit for calibrating a level adjusting unit

摘要

An optically recorded information recording and/or reading apparatus which eliminates the influence of stray light occurring within an optical system. In a state or a focus state which is forcedly set to position a reading point outside the outermost periphery of a disk surface, and the signal level is adjusted in a signal combiner circuit such that a light receiving level at that time matches a desired level.