Abstract: An optical pickup actuator independently drivable in focusing, tilting and tracking directions. The optical pickup includes a lens holder movably installed on a base, and mounted with an objective lens for transmitting an incident light to an optical information recording medium; and a magnetic circuit to independently driving the lens holder in the focusing, tilting and tracking directions. The magnetic circuit includes opposing magnets; a focusing coil and tilting coils interposed between the magnets, mounted inside the lens holder, and wound around respective axes parallel to the focusing direction; and a plurality of tracking coils mounted outside the lens holder, interposed between the magnets and wound around respective axes transverse to the focusing direction. The magnetic fields of the magnets are guided by outer yokes partially encompassing the magnets and inner yokes positioned within the focusing coil and the tilting coils.

Abstract: A photo-curable adhesive composition including an oligourethane acrylate in a range of about 10 to about 30% by weight, a reactive monomer-diluent in a range of about 32 to about 46% by weight, a polymeric filler in a range of about 20 to about 30% by weight, a photoinitiator in a range of about 2.5 to about 5.0% by weight, an antioxidant in a range of about 0.005 to about 0.02% by weight, a chlorinated polyvinyl chloride in a range of about 3.0 to about 10%, the chlorinated polyvinyl chloride having a chlorine content of about 62 to about 64% by weight, oxalic acid in a range of about 0.3 to about 2.0% by weight, a thixotropic agent in a range of about 0.5 to about 3.0% by weight, and a plasticizer in a range of about 1.0 to about 10.0% by weight, based on the total weight of the composition.

Abstract: A photo-curable adhesive composition includes oligourethane acrylate in a range of about 11 to about 23% by weight, reactive monomer-diluent in a range of about 11 to about 24% by weight, silicate filler in a range of about 50 to about 65% by weight, photoinitiator in a range of about 2.5 to about 5.0% by weight, organic peroxide in a range of about 0.1 to about 0.5% by weight, thixotropic agent in a range of about 0.5 to about 3.5% by weight, antioxidant in a range of about 0.005 to about 0.02% by weight, silane finishing agent in a range of about 0.1 to about 2.5% by weight, and oxalic acid in a range of about 0.5 to about 1.5% by weight, based on the total weight of the composition.

Abstract: A light emitting module and method and an optical pickup apparatus employing the same are provided. The light emitting module includes a base, a semiconductor laser that is disposed on the base and emits a laser beam of a predetermined wavelength, a cap surrounding the semiconductor laser, a beam shaping window that is fitted with a predetermined portion of the cap corresponding to the propagation path of the laser beam and shapes a transmitted laser beam while reflecting a portion of an incident beam, and a quarter wave plate that is disposed in the propagation path of the laser beam and in front of the beam shaping window and transforms a laser beam horizontally polarized after passing through the beam shaping window into a circularly polarized beam while converting a beam reflected from an optical disc into a vertically polarized beam.

Abstract: An optical pickup apparatus for an optical disc drive, including: a base; a turntable disposed above the base and which rotates an optical disc; an optical pickup unit which reciprocates with respect to the turntable in a radial direction of the turntable; a driving part which moves the optical pickup unit with respect to the turntable; and a guide unit having an auxiliary guide which supports an end of the optical pickup unit and which guides the optical pickup unit along a moving path. The optical pickup unit and the auxiliary guide are in line-contact with each other.

Abstract: A photo-curable adhesive composition including an oligourethane acrylate in a range of about 10 to about 30% by weight, a reactive monomer-diluent in a range of about 32 to about 46% by weight, a polymeric filler in a range of about 20 to about 30% by weight, a photoinitiator in a range of about 2.5 to about 5.0% by weight, an antioxidant in a range of about 0.005 to about 0.02% by weight, a chlorinated polyvinyl chloride in a range of about 3.0 to about 10%, the chlorinated polyvinyl chloride having a chlorine content of about 62 to about 64% by weight, oxalic acid in a range of about 0.3 to about 2.0% by weight, a thixotropic agent in a range of about 0.5 to about 3.0% by weight, and a plasticizer in a range of about 1.0 to about 10.0% by weight, based on the total weight of the composition.

Abstract: A photo-curable adhesive composition includes oligourethane acrylate in a range of about 11 to about 23% by weight, reactive monomer-diluent in a range of about 11 to about 24% by weight, silicate filler in a range of about 50 to about 65% by weight, photoinitiator in a range of about 2.5 to about 5.0% by weight, organic peroxide in a range of about 0.1 to about 0.5% by weight, thixotropic agent in a range of about 0.5 to about 3.5% by weight, antioxidant in a range of about 0.005 to about 0.02% by weight, silane finishing agent in a range of about 0.1 to about 2.5% by weight, and oxalic acid in a range of about 0.5 to about 1.5% by weight, based on the total weight of the composition.

Abstract: An optical pickup includes a light source which emits first and second lights having different wavelengths for a first recording medium and a second recording medium having a relatively large thickness, respectively, an optical path changer which alters a traveling path of incident light, and an objective lens which focuses the first and second lights on the recording medium. While the light source emits the first light, a photodetector is adjusted to be aligned with the optical axis for the first recording medium. The light source and/or a sensing lens are adjusted in the direction of the optical axis, and the tilt of the objective lens is adjusted. Next, while the light source is operated to emit the second light, the light source is adjusted in a rotating direction. As such, an optical axis alignment is completed for the first and second recording media.

Abstract: An optical pickup actuator independently drivable in focusing, tilting and tracking directions. The optical pickup includes a lens holder movably installed on a base, and mounted with an objective lens for transmitting an incident light to an optical information recording medium; and a magnetic circuit to independently driving the lens holder in the focusing, tilting and tracking directions. The magnetic circuit includes opposing magnets; a focusing coil and tilting coils interposed between the magnets, mounted inside the lens holder, and wound around respective axes parallel to the focusing direction; and a plurality of tracking coils mounted outside the lens holder, interposed between the magnets and wound around respective axes transverse to the focusing direction. The magnetic fields of the magnets are guided by outer yokes partially encompassing the magnets and inner yokes positioned within the focusing coil and the tilting coils.

Abstract: A method of arranging an optical pickup system on a deck of an optical recording and/or reproducing apparatus, which enables detection of a tracking error signal using one photodetector based on a three-beam method and by a differential phase detection method. The optical pickup system includes a light source, a diffractive optical element which diffracts a light beam incident from the light source and splits the same into at least three beams, a plate-type beam splitter which changes a propagation path of the light beam, and a photodetector including at least one main photodetector having at least four sections and a plurality of sub-photodetectors. The optical pickup system is constructed so as to have a reflecting mirror redirect the propagation path of the light beam emitted from the light source toward a recording medium.

Abstract: An optical pickup apparatus for an optical disc drive, including: a base; a turntable disposed above the base and which rotates an optical disc; an optical pickup unit which reciprocates with respect to the turntable in a radial direction of the turntable; a driving part which moves the optical pickup unit with respect to the turntable; and a guide unit having an auxiliary guide which supports an end of the optical pickup unit and which guides the optical pickup unit along a moving path. The optical pickup unit and the auxiliary guide are in line-contact with each other.

Abstract: A light emitting module and method and an optical pickup apparatus employing the same are provided. The light emitting module includes a base, a semiconductor laser that is disposed on the base and emits a laser beam of a predetermined wavelength, a cap surrounding the semiconductor laser, a beam shaping window that is fitted with a predetermined portion of the cap corresponding to the propagation path of the laser beam and shapes a transmitted laser beam while reflecting a portion of an incident beam, and a quarter wave plate that is disposed in the propagation path of the laser beam and in front of the beam shaping window and transforms a laser beam horizontally polarized after passing through the beam shaping window into a circularly polarized beam while converting a beam reflected from an optical disc into a vertically polarized beam.

Abstract: A method of arranging an optical pickup system on a deck of an optical recording and/or reproducing apparatus, which enables detection of a tracking error signal using one photodetector based on a three-beam method and by a differential phase detection method. The optical pickup system includes a light source, a diffractive optical element which diffracts a light beam incident from the light source and splits the same into at least three beams, a plate-type beam splitter which changes a propagation path of the light beam, and a photodetector including at least one main photodetector having at least four sections and a plurality of sub-photodetectors. The optical pickup system is constructed so as to have a reflecting mirror redirect the propagation path of the light beam emitted from the light source toward a recording medium.

Abstract: An optical pickup includes a light source which emits first and second lights having different wavelengths for a first recording medium and a second recording medium having a relatively large thickness, respectively, an optical path changer which alters a traveling path of incident light, and an objective lens which focuses the first and second lights on the recording medium. While the light source emits the first light, a photodetector is adjusted to be aligned with the optical axis for the first recording medium. The light source and/or a sensing lens are adjusted in the direction of the optical axis, and the tilt of the objective lens is adjusted. Next, while the light source is operated to emit the second light, the light source is adjusted in a rotating direction. As such, an optical axis alignment is completed for the first and second recording media.