摘要:
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. The optical structure of the optical pickup apparatus is simple which enables easy assembly and manufacture and provides signal regeneration when operating in a high temperature.
摘要:
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.
摘要:
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. The optical structure of the optical pickup apparatus is simple which enables easy assembly and manufacture and provides signal regeneration when operating in a high temperature.
摘要:
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. The method of arranging the optical pickup includes, where the propagation path of the light beam transmitted through the plate-type beam splitter to the photodetector is an optical path axis, arranging the optical pickup system so as to have the optical path axis tilted with respect to an axis in a tangential direction of the recording medium and have the photodetector placed away from a rotation center of a motor that rotates the recording medium, and selectively optimizing the arrangement of the photodetector to detect a tracking error signal by the differential phase detection method.
摘要:
An optical pick-up apparatus and method incorporating a spherical aberration compensator is disclosed. The optical pick-up employs the spherical aberration device that comprises a wave plate for converting the phase of beams entering the wave plate and outputting the phase-converted beams; and a liquid crystal panel having a molecular structure for adjusting the phase of circularly-polarized beams, whereby it is possible to compensate for the spherical aberrations of the laser beams emitted from a light source and entering an optical recording medium, and the laser beams which are reflected from the optical recording medium and reenter the liquid crystal panel. As a result, jitter characteristic of the optical pick-up can be enhanced.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
An optical recording/reproducing apparatus featuring stable information signal detection ability and reduced number of components. The optical recording/reproducing apparatus includes: 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.
摘要:
An optical reproducing apparatus having a photo detector using a laser diode of two wavelengths. A 16-split photo diode for detecting laser beams respectively for a DVD and a CD enables an optical pick-up compatible with a wide variety of optical discs to be achieved by applying the laser diode of two wavelengths. Focusing error signals and tracking error signals are detected by using different methods according to a type of optical disc, improving production yield and decreasing manufacturing costs of a multi-disc reproduction apparatus.