Patent ID: 7881168

Claim:
An optical pickup apparatus comprising: a light source module having a first light source and a second light source which emit light rays of different wavelengths to record/reproduce data on/from recording media having different standards, the first light source emitting light rays corresponding to a first recording medium and the second light source emitting light rays corresponding to a second recording medium, the light source module operating a selected one of the first and the second light sources; an object lens arranged to focus light rays emitted from the selected light source to form an optical spot on a predetermined position of a recording surface of a recording medium; a light splitting element arranged to transmit a part of the light rays emitted from the selected light source and reflect the remaining light rays to oppose to the object lens, the light splitting element transmitting all of the light rays reflected from the recording medium; a collimating lens arranged on a light path formed between the light splitting element and the object lens to convert the light rays into parallel light rays; a hologram module arranged on a light path between the collimating lens and the object lens to split a light which is incident to the recording medium, into a plurality of beams; and a photo-detector having a sensor corresponding to the first/second recording medium to receive light rays that are reflected from the recording medium and passed through the hologram module and detecting an information signal and an error signal, wherein the hologram module comprises: a polarized light hologram formed in a circular pattern to split only predetermined polarized light rays; and a ¼-wavelength plate arranged on a surface of the polarized light hologram opposite to the object lens to tune a phase of the polarized light rays by 90°, wherein the polarized light hologram is divided into a first hologram and a second hologram which are operated in response to the light rays emitted from the first light source, the first and the second holograms being formed on the same plane in a semicircular shape and located one on the other, the first and the second holograms diffracting the light rays by a predetermined angle with respect to an optical axis of the light rays to thereby generate zero-order and ±1 order beams, and wherein the zero-order beam generated by the first and the second holograms is focused by the object lens on a predetermined position conforming to the standard of a DVD-ROM.