Patent ID: 8248442

Claim:
A side determination apparatus of an optical disc, comprising: a light source illuminating one side of the optical disc obliquely, the optical disc having a data side and a non-data side; a plurality of sensors receiving light reflected in a normal direction of the optical disc illuminated by the light source; and a determination unit determining that incident light into the plurality of sensors is reflected diffracted light from the data side of the optical disc when: a first signal, which is obtained by receiving the reflected diffracted light from a first region situated at a front or back position of a center of the optical disc in a region on the optical disc with respect to a direction of the oblique illumination, indicates luminance exceeding a threshold value, and a second signal, which is obtained by receiving the reflected diffracted light from a second region situated at a left or right position of a center of the optical disc in a region on the optical disc with respect to a direction of the oblique illumination, indicates luminance less than a threshold value.