Abstract:
An apparatus for and a method of reproducing information from an optical information storage medium (OISM) in which inherent information and control data are recorded according to a bi-phase modulation method and other data are recorded according to a general modulation method. Sum signals of signals reflected from the OISM are determined. A ROM-PIC demodulator demodulates optical information storage medium-related information (OISMRI) from the sum signal. A data demodulator demodulates reproduction-related user data from the sum signal, a wobble PIC demodulator demodulates recordable OISMRI recorded as pit wobbles from a differential signal of the reflected signals, and a wobble PID demodulator demodulates physical identification data that is recorded as pit wobbles from the differential signal. A determination is made whether the OISM is a read-only OISM or a recordable OISM based on whether the optical information storage medium comprises a plurality of different modulation codes.
Abstract:
A disc cartridge includes a case accommodating a disc and having an aperture hole formed on a first surface of the case so that a recording/reproducing apparatus access a recording surface of the disc, and an open hole formed on a second surface to be open to an outside of the case, a shutter opening/shutting the aperture hole and installed in the case, a disc holder installed at a side defining the open hole to move up and down and covering a gap between an outer circumference of the disc and an inner surface of the side defining the open hole when the disc holder descends, and a shutter driving mechanism moving the shutter so that the aperture hole is open/shut. Thus, a passage through which dust is introduced toward an information area of the disc, and a gap formed at an outer circumference are blocked by the disc holder so that a possibility of contamination by dust can be reduced.
Abstract:
An optical head includes a substrate, a laser diode, a photodetector, an objective lens, a prism, and an optical element. The laser diode is installed on the substrate and emits light. The photodetector is installed on the substrate and receives the light. The objective lens is installed on a first side of the substrate and focuses the light emitted from the laser diode onto a recording surface of a disc. The prism is installed on a second side of the substrate, transmits the light emitted from the laser diode toward the objective lens, and transmits the light reflected from the recording surface toward the photodetector. The optical element adjusts an optical path formed between the substrate and the prism.
Abstract:
A compatible optical pickup includes an optical disc, an objective lens, a diffractive device, and a divergent lens. The optical unit emits a short wavelength light beam corresponding to a high density optical disc and a long wavelength light beam corresponding to a low density optical disc. The objective lens forms a light spot on the high density optical disc and the low density optical disc and the diffractive device diffracts the short wavelength light beam to correct chromatism according to a change in a wavelength of the short wavelength light beam. The divergent lens refracts the long wavelength light beam toward the objective lens to increase a working distance with respect to the low density optical disc.
Abstract:
An optical disc apparatus and a wobble signal detection method in which a light beam projected onto an optical disc and reflected by the optical disc is divided into at least four light regions in the direction corresponding to the radial direction of the optical disc to detect the light regions, and a wobble signal is detected by performing a subtraction on first and second difference signals, the first difference signal obtained by performing a subtraction on detection signals for the inner light regions of the divided and/or detected light beam and the second difference signal obtained by performing a subtraction on detection signals for the outer light regions of the divided and/or detected light beam. Accordingly, when a wobble signal is reproduced from an optical disc manufactured by a wobble modulation manner, a wobble signal is prevented from being degraded due to the interference (cross talk) from the wobbles of adjacent tracks, even though the track pitch of the optical disc is reduced to improve the recording density.
Abstract:
An objective lens device and an optical pickup employing the objective lens device. The objective lens device is formed of three lenses including a lens having a negative power and formed of material having an Abbe number which is 45 or less in line d. At least one surface of surfaces of the three lenses is formed to be aspherical. Thus, in the objective lens device, a high numerical aperture of 0.70 or more is realized and chromatic aberration is corrected with respect to blue light enabling improved recording and/or reproduction using blue light.
Abstract:
An actuator for an optical pickup includes a base, a holder fixed to the base, a moving portion on which an objective lens for focusing incident light onto a disc and a liquid crystal panel for correcting spherical aberration are mounted, a magnetic driving portion which drives the moving portion in a radial direction and in a focusing direction relative to the disc, and a connection section which includes a first connection part which serves as an electrical connection path of a signal used to drive the magnetic driving portion and has at least four wires, and a second connection part electrically independent of the first connection part, which serves as an electrical connection path of a signal used to drive the liquid crystal panel, and has wires, and which supports the moving portion to be movable with respect to the holder.
Abstract:
A compatible optical pickup for recording and/or reproducing information on/from multiple kinds of optical discs having different thicknesses by selectively using source lights of respective different wavelengths corresponding to a kind of disc and using a common objective lens. At least one phase compensator, which compensates a phase of a light having a particular wavelength to correct for spherical aberration due to a thickness difference between the kinds of optical discs and/or chromatic aberration due to a wavelength difference between the required source lights, is positioned between the source lights and an entrance pupil of the objective lens. Each phase compensator compensates light of at least one wavelength and passes light of at least one other wavelength without significant relative phase alteration. By using two phase compensators, the optical pickup may be made compatible with at least three kinds of optical discs.
Abstract:
A disk cartridge has a reflection portion to identify a kind of a disk in the disk cartridge. A disk drive apparatus has an optical detector to identify the kind of the disk by irradiating a beam to the reflection portion and detecting the reflected beam. The disk cartridge and the disk drive apparatus provide identification marks for identifying the kind of the disk by varying the angle and amount of a beam reflected from the reflection portions on the disk cartridge. Therefore, the kind of a disk and the type of a disk format are identified as well as the storage capacity of the disk.
Abstract:
A compact high-density optical disc capable of securing recording/reproducing characteristics and high-density recording capacity. The high-density optical disc has a whole diameter of 80 mm or less to 28 mm, a whole thickness in a range of 0.3-0.7 mm, and a position where data starts being recorded in a range of 27-45 mm of the diameter. Thus, an existing disc drive can be used, the size of the high-density optical disc can be reduced, and high-density recording capacity can be secured.