Patent ID: 6442124
Filing Date: 2002-08-27
Classification: G11B

Abstract:
An optical pick-up apparatus for recording and/or reproducing information from first through third recording media, comprising:a first light source to emit a light beam having a wavelength corresponding to the first recording medium when the first recording medium is accessed; a second light source to emit a light beam having a wavelength corresponding to the second recording medium when the second recording medium is accessed; a third light source to emit a light beam having a wavelength corresponding to the third recording medium when the third recording medium is accessed; a dichroic beam splitter having first through third input surfaces to receive the light emitted from the first through third light sources, respectively, dielectric surfaces to receive the light from the first through third input surfaces, and an output surface through which the light beams received by the first through third input surfaces and the dielectric surfaces are transmitted toward the first, the second, and the third recording media, respectively, each dielectric surface comprising repeated stacks of dielectric layers; a converging device to converge each of the light beams transmitted through the output surface of the dichroic beam splitter toward the respective first through third recording media; and first through third photodetectors to respectively receive the light beams reflected from the respective first through third recording media and which pass through the dichroic beam splitter.