Abstract: An optical pickup device, which reduces the size of an optical spot formed on an optical disk, and prevents the degradation of a tracking error signal due to coherent light from a layer adjacent a target recording/reproducing layer of the optical disk. The optical pickup device includes a light source emitting light at a designated wavelength; an object lens concentrating the light incident from the light source thereupon and forming an optical spot on an optical disk having multiple recording layers; and an optical detector receiving the light reflected by the optical disk and detecting a data signal and an error signal, wherein at least one diffraction pattern region partially diffracting or intercepting the light, emitted from the light source and being incident upon the object lens, and the light, reflected by optical disk and being incident upon the object lens, is formed on the object lens.

Abstract: An optical pickup apparatus is provided for use in a recording/reproducing apparatus to record/reproduce information on/from recording media having different formats. Such an optical pickup apparatus comprises a dual wavelength laser diode; a hologram module arranged to split a light which is incident to a recording medium into a plurality of beams; and a photo-detector arranged to receive a light beam reflected from the recording medium and detect an information signal and a signal for servo control. Each of the split beams is focused on a predetermined position corresponding to a format of the recording medium. The light beams reflected from the recording medium are detected by the photo-detector to generate a focus error signal and a tracking error signal. Thus, the optical pickup apparatus records and reproduces information on and from recording media having different formats by using a hologram of a simple pattern.

Abstract: A compatible optical pickup can be used with advanced optical discs (AODs), blu-ray discs (BDs), digital versatile discs (DVDs), and compact discs (CDs). The compatible optical pickup comprises a first light source unit for independently projecting first and second short-wavelength laser beams which have different polarizations, a second light source unit for independently projecting first and second long-wavelength laser beams which have different wavelength-range, a first objective lens that has a high numerical aperture suitable for a high density optical information recording medium, a second objective lens that has a low numerical aperture suitable for a low density optical information recording medium, and a light path changing unit for guiding the first short-wavelength laser beams to the first objective lens and guiding the second short-wavelength laser beams, the first long-wavelength laser beams, and the second long-wavelength laser beams to the second objective lens.

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: An optical pickup actuator is provided. The actuator comprises a bobbin, on which one or more objective lenses are mounted for allowing light to be incident onto an optical information storage medium, and which is supported by a support member to be movable in relation to a base. The actuator also comprises a magnetic circuit for independently driving the bobbin in focusing and tilt directions.

Abstract: An optical pickup actuator comprises a lens holder having an object lens which focuses a laser beam onto an optical information storage medium mounted thereon. In the optical pickup actuator the lens holder is movably supported by a support member with respect to a base. The optical pickup actuator also comprises a magnetic circuit to drive the lens holder in a focusing direction and a tilt direction independently.

Abstract: An optical recording/reproducing apparatus including a plurality of light sources emitting lights with different wavelengths for use in recording/reproducing information onto/from various types of optical recording media of different recording densities, in which at least two lights emitted from the light sources have polarization components orthogonal to each other; an objective lens for focusing a light from each of the light sources to a corresponding optical recording medium; a collimating lens disposed between the light sources and the objective lens for collimating lights from the light sources; a hologram element installed between the collimating lens and the objective lens for refracting a light emitted from one of the light sources, in which the light to be refracted is selected by wavelength and polarization components; and a photodetector receiving a light that is reflected from the corresponding optical recording medium after being focused by the objective lens.

Abstract: An optical pickup actuator and a method of assembling the same is provided. The method of assembling the optical pickup actuator comprises the steps of providing a blade having at least one objective lens mounting area and an aberration correcting mechanism mounting area, arranging an objective lens in the objective lens mounting area, positioning an aberration correcting mechanism in the aberration correcting mechanism mounting area such that the central point of the aberration correcting mechanism coincides with the central point of the objective lens, tuning the aberration correction mechanism, and adhering the aberration correcting mechanism using an adhesive.

Abstract: A compatible optical pickup includes a light source which emits a first light beam having a wavelength for a first recording medium; a twin light source which emits second and third light beams respectively having wavelengths for second and third recording media; a first objective lens which condenses the first light beam to form a light spot for recording and/or reproduction of the first recording medium; a second objective lens which condenses the second and third light beams to form light spots for recording and/or reproduction of the second and third recording media; an actuator which drives the first and second objective lenses; a first photo-detector which receives the first light beam reflected from a recording medium to detect an information signal and/or an error signal; and a second photo-detector which receives the second and third light beams reflected from a recording medium to detect information signals and/or error signals.

Abstract: A photo detector for use in an optical pickup apparatus that detects a beam reflected from the disc, and includes a substrate for transmitting one main beam and two sub beams reflected from the optical disc; a liquid crystal for refracting the two sub beams, that are transmitted through the substrate, at different refractive indexes according to the wavelength of a laser beam outputted from the laser diode; an electrode material for supplying power to the liquid crystal; a switch for adjusting the magnitude of an applied voltage to the electrode material; and a photodiode on which the main beam and the refracted sub beams while transmitting the substrate and the liquid crystal are projected, and transformed into electric signals. By refracting the beams refracted from the disc at a proper refractive index, the ±1st-order beams can be projected onto the same position, irrespective of the wavelengths.

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: An optical pickup apparatus and method are provided. The apparatus and method include a light source unit having a holder in which an optical module having first and second light sources for emitting light having different wavelengths and a grating are installed, an optical path changer for changing a path of the light emitted from the first or second light sources, an object lens for focusing light passing through the optical path changer on a relatively thin disc or a relatively thick disc, and a photodetector unit.

Abstract: An optical pickup including an optical member which inhibits interference light reflected from an adjacent layer from being received by a photodetector when an optical information storage medium includes a plurality of recording layers on at least one side thereof. The optical pickup suppresses a photodetector, especially first and second sub-photodetectors of the photodetector, from receiving the interference light reflected from the adjacent layer.

Abstract: A CD-DVD compatible optical pickup in which both on-axis and off-axis light form a circular light spot on a recording surface of an optical recording medium, and an optical recording and/or reproducing apparatus using the same. The CD-DVD compatible optical pickup includes an optical output module, an objective lens, an optical path conversion unit, a photodetector, and an actuator. The optical output module has a mount and light sources emitting light of different wavelengths. The objective lens focuses the emitted light onto two types of optical recording media. The optical path conversion unit between the optical output module and objective lens, converts incident light. The photodetector receives beams emitted from the light sources, reflected from the optical recording media, and then passed through the optical path conversion unit, detecting data and error signals. The actuator has a movable member, moving the objective lens and compensating focusing and tracking error signals.

Abstract: An optical pickup apparatus is provided for use in a recording/reproducing apparatus to record/reproduce information on/from recording media having different formats. Such an optical pickup apparatus comprises a dual wavelength laser diode; a hologram module arranged to split a light which is incident to a recording medium into a plurality of beams; and a photo-detector arranged to receive a light beam reflected from the recording medium and detect an information signal and a signal for servo control. Each of the split beams is focused on a predetermined position corresponding to a format of the recording medium. The light beams reflected from the recording medium are detected by the photo-detector to generate a focus error signal and a tracking error signal. Thus, the optical pickup apparatus records and reproduces information on and from recording media having different formats by using a hologram of a simple pattern.

Abstract: An optical recording/reproducing apparatus featuring stable information signal detection ability and reduced number of components.

Abstract: A compatible optical pickup can be used with advanced optical discs (AODs), blu-ray discs (BDs), digital versatile discs (DVDs), and compact discs (CDs). The compatible optical pickup comprises a first light source unit for independently projecting first and second short-wavelength laser beams which have different polarizations, a second light source unit for independently projecting first and second long-wavelength laser beams which have different wavelength-range, a first objective lens that has a high numerical aperture suitable for a high density optical information recording medium, a second objective lens that has a low numerical aperture suitable for a low density optical information recording medium, and a light path changing unit for guiding the first short-wavelength laser beams to the first objective lens and guiding the second short-wavelength laser beams, the first long-wavelength laser beams, and the second long-wavelength laser beams to the second objective lens.

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 actuator is provided. The actuator comprises a bobbin, on which one or more objective lenses are mounted for allowing light to be incident onto an optical information storage medium, and which is supported by a support member to be movable in relation to a base. The actuator also comprises a magnetic circuit for independently driving the bobbin in focusing and tilt directions.

Abstract: An optical pickup actuator and a method of assembling the same is provided. The method of assembling the optical pickup actuator comprises the steps of providing a blade having at least one objective lens mounting area and an aberration correcting mechanism mounting area, arranging an objective lens in the objective lens mounting area, positioning an aberration correcting mechanism in the aberration correcting mechanism mounting area such that the central point of the aberration correcting mechanism coincides with the central point of the objective lens, tuning the aberration correction mechanism, and adhering the aberration correcting mechanism using an adhesive.