Multivalued information reproducing Method and multivalued information reproducing apparatus

摘要

A multivalued information reproducing apparatus includes: a light source which emits linear polarized light having a prescribed polarization direction; a first optical system which generates first linear polarized light and second linear polarized light that have different polarization directions using the linear polarized light which is emitted from the light source and makes the two polarized lights input to an optical recording medium in which the polarization directions of recording light are recorded as multivalued information; a second optical system which has a transmission light selecting element that selectively transmits emission light generated when the light passes the first optical system is input to the optical recording medium and by which the emission light that passes the transmission light selecting element is directed to a photo detecting portion in a state where first emission light that has a same polarization direction as the first linear polarized light and second emission light that has a same polarization direction as the second linear polarized light are separated; and a polarization direction judging portion which judges the polarization direction that is recorded in the optical recording medium based on amount of light of the first emission light and amount of light of the second emission light that are obtained by the photo detecting portion.