Abstract: A method of detecting a servo error, an apparatus therefor, a disk which maintains quantity of a servo error signal, a method of controlling a servo of an apparatus for recording data on and reproducing data from a disk, a method of detecting the tracking error, and a method of detecting tilt error of the apparatus.

Abstract: An error signal detecting apparatus for an optical recording/reproducing apparatus, the error signal detecting apparatus including a photodetector to receive light reflected and diffracted by a recording medium, and a signal processor to detect an error signal by calculating a detection signal of the photodetector. The photodetector includes a plurality of light receiving areas to independently receive light of a light area in which the profile of the light changes to the opposite profile according to the tangential tilt of the recording medium. The signal processor detects a tangential tilt error signal from detection signals of the light receiving areas. Thus, a signal output from the error signal detecting apparatus does not change when a shift is generated in the objective lens or the distance between the objective lens and the disc is deviated from the on-focus position.

Abstract: A disk cartridge includes a case accommodating a disk, a cover installed at the case to be capable of being open and shut and having a hole formed thereon to be open to an outside of the cover, a shutter installed under the disk in the case to be capable of moving to open and shut an opening formed on the case, and a clamping member installed at the cover to seal the hole to clamp the disk. Thus, since the clamping member blocks the hole of the cover connected to the outside of the cover, possibility of intrusion of dust into the disk cartridge is reduced. Also, since there is no need to install the clamping member at the disk drive, the disk drive can be made simplified and slim.

Abstract: A method of detecting a servo error, an apparatus therefor, a disk which maintains quantity of a servo error signal, a method of controlling a servo of an apparatus for recording data on and reproducing data from a disk, a method of detecting the tracking error, and a method of detecting tilt error of the apparatus.

Abstract: A disk cartridge includes a case to accommodate a disk, and a shutter installed in the case to move under the disk, and to selectively open/shut an opening hole formed in the case. The disk cartridge includes a support portion to protrude from the shutter to support a non-information area of the disk. Thus, since the shutter contacts only the non-information area of the disk, the information area of the disk is protected during an operation of the shutter to open and shut the opening hole.

Abstract: A swing arm driving type optical recording/reproducing apparatus includes a base, at least one optical disk rotatably installed on the base, both sides of which are information recording surfaces and a plurality of optical pickups which are equal in number to the information recording surfaces so as to form light spots on the respective information recording surfaces of the optical disk. Each optical pickup includes a light source for irradiating light. The apparatus also includes optical path changing units respectively arranged on optical paths between the light sources and respective ones of the information recording surfaces for changing the traveling paths of the lights and objective lenses arranged between the optical path changing units and the respective information recording surfaces for condensing incident light on the respective information recording surfaces.

Abstract: An optical pickup including: first and second light sources for generating first and second laser beams having different wavelengths corresponding to first and second media having different thicknesses, respectively; an objective lens that has diverging and converging/focusing portions, to focus the first and second laser beams from the first and second light sources onto the first and second media, respectively; a photodetector to receive the first and second laser beams that are emitted from the first and second light sources and reflected, respectively, by the first and second media; and a collimating lens arranged on the optical path between the objective lens, and the first and second light sources. The optical pickup is compatible with both existing digital versatile disks (DVDs), and high-definition (HD)-DVDs, which need a blue light source near 405 nm and an objective lens that has a numerical aperture of 0.6 or more.

Abstract: A tracking error signal detecting apparatus with improvement in offset due to gain characteristics and/or a difference in the depth between pits by providing an improved sectioning structure of an eight-sectional photodetector having inner and outer sectional plates, the radial widths of which vary along the tangential direction from the center of the photodetector, and a reproduction signal detecting apparatus with reduced crosstalk noise. The tracking error signal detecting apparatus can allow accurate tracking control in a high-density recording medium having relatively narrow tracks. Also, the reproduction signal detecting apparatus can correct signal distortion due to a difference between phase characteristics of detection signals of inner and outer sectional plates of a photodetector even during reproduction of an information signal from a high-density recording medium having relatively narrow tracks, thereby detecting an improved reproduction signal with greatly reduced crosstalk.

Abstract: An optical pickup including a light detection element to divide light reflected from an optical recording medium into first through fourth light beam portions in a radial direction of the optical recording medium. From detection signals from the light detection element, a reproduction signal detection portion detects an information signal, and a tracking error signal detection portion detects a tracking error signal. The light source emits light that is focused as a single light spot on a main track of the optical recording medium. The tracking error signal detection portion gain controls and sums push-pull signals from the detection signals to detect, during a recording operation, a tracking error signal with reduced push-pull offset without erasing existing signals on adjacent tracks. The reproduction signal detection portion sums and gain controls the detection signals to detect an information signal containing reduced crosstalk from adjacent tracks.

Abstract: A disk clamping apparatus for a disk player includes a turntable for receiving a disk, a disk clamper which clamps the disk placed on the turntable, and first and second magnetic bodies which are mounted in the corresponding turntable and the disk clamper and provide a clamping force to the disk by acting a reciprocal magnetic force on the turntable and the disk clamper. The first and second magnetic bodies are opposite to each other and partially overlap each other. In the disk clamping apparatus having the above structure, the variation in a clamping force caused by the variation in thickness of disks, received by the disk clamping apparatus, is very small. Accordingly, clamping and de-clamping of the disks having different thickness can be smoothly performed.

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: 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: An optical pickup compatible with optical discs having different formats. A first light source emits a first light beam suitable for a first format optical disc. An objective lens is optimized for a wavelength of the first light source. Light reflected from the first optical disc provides a reproduction signal. A second light source emits a second light beam suitable for a second format optical disc. A light splitter splits the second light beam and the objective lens focuses the split beams onto the second disc as a main light spot and a sub-light spot. Lights reflected from the main light spot and the sub-light spot are independently detected and then processed to correct for chromatic aberration caused by a difference in the wavelengths of the first and second light beams and/or spherical aberration caused by thickness difference between the first and second format optical discs.

Abstract: A high density disc having a data area which is set such that compatibility is secured in the same drive while maintaining a superior recording and/or reproducing feature. The high density disc has a center hole, a clamping area, a data area where user data is recorded, a lead-in area located at the inner side of the data area, and a lead-out area located at the outer side of the data area. In the high density disc in which the diameter of the center hole is 10 mm or more, the inner diameter of the clamping area is characteristically within a range of 20-26 mm. Also, the inner diameter of the data area is characteristically within a range of 35-40 mm. Therefore, while a conventional disc drive is still used, the size of the high density disc decreases and a recording capacity can be increased.

Abstract: A spherical aberration compensator for compensating for spherical aberration resulting from a thickness deviation of a recording medium. The spherical aberration compensator includes a central compensation which provides a phase distribution that is effective for compensating for spherical aberration resulting from the thickness deviation and a peripheral compensation portion which surrounds the central compensation portion and provides a phase distribution that is effective for reducing a worsening of the spherical aberration caused by axial displacement of an objective lens from the central compensation portion. The spherical aberration compensator effectively relieves an optical pickup having an objective lens of an NA of 0.7 or greater of worsening of the spherical aberration resulting from thickness deviation of the recording medium.

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 method of detecting a servo error, an apparatus therefor, a disk which maintains quantity of a servo error signal, a method of controlling a servo of an apparatus for recording data on and reproducing data from a disk, a method of detecting the tracking error, and a method of detecting tilt error of the apparatus.

Abstract: A method of detecting a servo error, an apparatus therefor, a disk which maintains quantity of a servo error signal, a method of controlling a servo of an apparatus for recording data on and reproducing data from a disk, a method of detecting the tracking error, and a method of detecting tilt error of the apparatus.

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.

Abstract: An optical pickup capable of reducing cross-talk due to signal interference of adjacent tracks of an optical medium during playback of a radio frequency (RF) signal from a main track of the optical recording medium. In the optical pickup, optical spots can be converged on the main track and the adjacent tracks of the recording medium without a time lag, wherein different polarized component beams are focused as a primary optical spot and secondary optical spots on the main and adjacent tracks, respectively, of the optical recording medium. Thus, the primary optical spot and the secondary optical spots, which have different polarized components, can be separately received by different light receiving portions. Also, the optical spots are photoelectrically converted in the light receiving portions and are differentially amplified through multiplication using a predetermined operation constant, thereby reducing cross-talk from a detected RF signal.