Abstract: An optical unit is provided for an optical pick-up apparatus which includes a light source to emit light entering into a recording medium. A light source holder has an optical passage hole formed corresponding to a direction of a reference optical axis of the light toward the recording medium. A plate part is coupled to a pickup base and a holding part supports the light source. The plate part and the pickup base are integrally formed with each other and an adjustable member adjusts the optical axis of the light source by transforming the holding part.

Abstract: A diffraction element for use in an optical pick-up is capable of calculating a TE signal more stably irrespective of any assembly error in optical elements. The diffraction element of the invention is divided into three areas, a first, a second, and a third area. Each area comprises a diffraction grating with a predetermined period, and the second area is provided between the first area and the third area. The diffraction grating of the first area is substantially parallel to the diffraction grating of the third area, and the diffraction grating of the second area is substantially perpendicular to the diffraction gratings of the first and the third area.

Abstract: A diffraction element for an optical pick-up apparatus is capable of precisely controlling the tracking of the pick-up apparatus. The diffraction element includes a diffraction grating divided into a first, a second, and a third region. The second region is located between the first and third regions. Any one of the first region and the third region is inclined at a predetermined angle e with respect to the second region.

Abstract: A diffraction element for an optical pick-up apparatus is capable of being used with discs that have different track pitches. The diffraction element includes a first region and a second region, each being constituted by a diffracting grating with a predetermined period. The first region and the second region have a predetermined height difference ?x.

Abstract: An optical pickup device for a relatively thick disc and/or a relatively thin disk including first and second laser light sources emitting first and second light beams, a first grating splitting the light beams emitted from the second light source, a beam splitter changing optical paths of the light beams emitted from the first and second laser light sources, and an objective lens focusing the light beams passing through the beam splitter onto one of the discs. A photodetector receives and detects the light beams that proceed back after being reflected by one of the discs. A second grating corrects a position of a light spot formed on the photodetector after being reflected by the relatively thin disc or the relatively thick disc, wherein the second grating includes a pattern that is rotated by a predetermined angle with respect to a pattern of the first grating.

Abstract: The present invention relates to a photosensitive resin composition, a preparation method thereof, and a dry film resist comprising the same. More particularly, the photosensitive resin composition of the present invention is directed to a photosensitive resin composition including a) an alkali-soluble acrylate resin, b) a cross-linking monomer having at least two ethylenic double bonds, and c) a phosphine oxide based photopolymerization initiator and an acridon based photopolymerization initiator. According to the photosensitive resin composition and the dry film resist, it is easy to finely pattern using a laser direct image with high density and the dry film has excellent sensitivity, resolution, and adhesiveness to the substrate.

Abstract: A diffraction element for an optical pick-up apparatus is provided that enables more accurate focusing control. The diffraction element for an optical pick-up apparatus is divided into first and second regions, each being formed with a grid pattern in which grids are repeated with a predetermined pitch P. The grid pattern in at least one of the first and second regions is tilted by a predetermined angle with respect to a virtual line VL substantially perpendicular to a division line DL that divides the first and second regions.

Abstract: A photosensitive composition, which has a cross-linking monomer having at least two ethylenic double bonds, a photopolymerization initiator, and an organic solvent, and a method of preparing a barrier rib for a plasma display panel, wherein the photosensitive composition is used. The photosensitive composition provides improved adherence to an inorganic material and an organic material.

Abstract: An optical pick-up apparatus including an optical source module having a CD optical source and a DVD optical source, a diffracting grating dividing a light beam from the optical source module to at least three divided light beams, a first optical divider changing a path of the divided light beams to an optical disk, a second optical divider reflecting and forwarding the divided light beams reflected from the optical disk in a predetermined ratio, a first optical detector including a single optical sensor receiving reflected light from the second optical divider, and a second optical detector including at least three optical detection sensors receiving forwarded light from the second optical divider. Embodiments of the present invention can provide support for multi-type optical disks with a simple optical structure.

Abstract: An optical pickup which can remove birefringence due to the non-uniformity of an optical recording medium by using a polarization beam splitter. The optical pickup includes a light source emitting a laser beam, a beam splitter reflecting part of incident light and straight transmitting the remaining light to change a proceeding path of the incident light, an objective lens focusing the incident light passed through the beam splitter to form a light spot on an optical recording medium, a polarization beam splitter arranged on an optical path between the beam splitter and the objective lens for transmitting light having one polarization and reflecting light having a different polarization.

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: An optical recording/reproducing apparatus, medium, and method and a controlling apparatus, medium, and method thereof. The recording/reproducing apparatus includes an optical pickup actuator including a holder formed on a base, a blade connected to the holder with a plurality of elastic supporters, a pair of focus coils for operating the blade in a focus direction, track coils for operating the blade in a tracking direction, magnets, a memory for storing a lookup table for the height of the blade according to electric current, a lookup table for the tilt of the blade according to the electric current supplied to the focus coils, a lookup table for the actual tilt of an optical disk according to the height of the blade, and a controller for computing a tilt difference between the optical disk and the blade and controlling the electric currents supplied to the focus coils to compensate for the tilt difference.

Abstract: An optical pickup apparatus and method for recording and/or reproducing information onto and/or from optical discs having diverse specifications. Particularly, a diffraction grating for use in the optical pickup apparatus includes a substrate for refracting an output beam from a laser diode at a predetermined refractive index, a liquid crystal for refracting the beam, which is transmitted through the substrate, at a different refractive index and direction according to a track pitch of the optical disc, an electrode material for supplying power to the liquid crystal, and a switch for controlling power supply to the electrode material. Electrode materials are aligned with various spacing in order to change the refractive index of the liquid crystal according to the wavelength of a laser and the specification of an optical disc used. Also, power supply to the electrode materials is controlled depending on the optical disc specification.

Abstract: The invention provides photoresist resin compositions and in particular, a photoresist resin compositions comprising a) an acrylate monomer having two urethane bonds, b) a crosslinkable urethane monomer having at least two ethylene double bonds, c) an alkali-soluble compound, d) a photopolymerization initiator and e) a solvent, and a photoresist dry film resists using the photoresist resins. The photoresist resin compositions and the photoresist dry film resists using the same in accordance with the invention have excellent adhesion to a substrate and sandblast resistance and at the same time, they have high sensitivity as well as high resolution, thereby enabling fine pattern formation on substrates.

Abstract: An optical pickup apparatus for reading and writing information from and to optical data media in different formats and a method thereof are provided. The optical pickup apparatus comprises a twin laser diode (Twin LD), a diffraction element for dividing a laser beam incident on a data medium into five beams, and an optical detector for focusing a laser beam reflected from the data medium to detect an information signal and signals for carrying out servo controls. The divided beams are focused on a predetermined location in based on a data medium format, and the beam reflected from the data medium is received on and detected from the corresponding photodiodes of the optical detector so that a focus error signal and a tracking error signal are generated.

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: Disclosed is an optical pickup including a polarization holographic optical element (HOE) and a photodetector. The optical pickup includes a light source, an optical path changer, an objective lens, a polarization HOE, and a photodetector. The polarization HOE has a pattern designed to generate different astigmatisms in the left and right halves of the polarization HOE in a tangential direction and to divide plus and minus first-order beams in a radial direction. The photodetector includes a first light-receiving portion receiving a zero-order beam and second and third light-receiving portion that are disposed on either side of the first light-receiving portion in the tangential direction and respectively receive the plus and minus first-order beams.

Abstract: A light emitting module and method for shaping a beam via a beam shaping window and an optical pickup apparatus employing the same. The light emitting module includes a base, a semiconductor laser that is installed 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 monitor photodetector that is disposed within the cap and receives the laser beam reflected by the beam shaping window in order to monitor the laser beam emitted by the semiconductor laser.

Abstract: A compatible optical pickup apparatus and method are provided. The apparatus and method include a first light source for generating and emitting a first light having a predetermined wavelength, a second light source for generating and emitting a second light having a wavelength different from the wavelength of the first light, a beam shaping beam splitter provided in paths of the first and second lights for shaping the first and second lights in order to change a shape of a profile of each of the first and second lights to a circular shape and change the paths of the first and second lights, an objective lens for focusing the first and second lights and forming light spots on an optical recording medium, and a main photodetector for receiving the first and second lights by being reflected from the optical recording medium and passing through the objective lens and the beam shaping beam splitter, and detecting an information signal and an error signal.

Abstract: An actuator and a method of operating an optical pickup of an optical disk drive comprises a blade on which an object lens is mounted, a plurality of magnets for generating a magnetic field, a plurality of focusing coils for interacting with the magnetic field generated at the magnets to move the blade in a first direction, a tracking coil for interacting with the magnetic field generated at the magnets to move the blade in a second direction, a first supporting member for supporting the blade so that the blade is tilted by the difference in electromagnetic forces which are generated between the magnets and the focusing coils, and a second supporting member connected to the first supporting member, for movably supporting the blade in the first and the second directions. Accordingly, the blade tilts in the tangential direction by adjusting the electric current supplied to the focusing coil.