Patent ID: 8004953
Filing Date: 2011-08-23
Classification: G11B

Abstract:
1. An optical pick-up comprising: a light source to emit light with a predetermined wavelength; a light collecting unit to collect the light emitted from the light source to form a light spot on a signal recording layer of an optical disc having a plurality of recording layers; a photodetector to receive the light reflected by the optical disc so as to detect a signal; and an optical member to change the optical transmission of the light reflected by the optical disc according to an incident angle of the reflected light so as to decrease a transmittance of the optical member with respect to a noise light entering the photodetector, wherein the optical member comprises a liquid crystalline layer to transmit a majority of parallel signal light reflected by the optical disc and having the liquid crystalline layer perpendicular thereto and to absorb non-parallel incident noise light to be converged or diverged, to change the optical transmission of the light according to an incident angle of the light.