Abstract: An optical disk clamping device. The device includes a diamagnetic member, a turntable, a magnet, and a clamping member. The turntable supports an optical disk. The magnet is disposed between the diamagnetic member and the turntable. The clamping member is disposed on the turntable to support the magnet. A repellent force is generated between the diamagnetic member and the magnet when the turntable rotates, pushing the magnet toward the clamping member to fix the optical disk.

Abstract: A method and disc drive in which tracks and data rates are designated is provided. Under the invention, the write width of a transducer head is determined. A tracks per inch value is adjusted based on the write width, and a data transfer rate is adjusted based on the adjusted tracks per inch value. In particular, the data transfer rate is adjusted such that the adjusted tracks per inch value and the adjusted data transfer rate provide a capacity for the head that is equal to a nominal capacity.

Abstract: A disk drive apparatus drives, by means of a motor, a disk mounted thereon so as to reproduce signals recorded in the disk. The disk drive apparatus has an edge detecting unit for generating an edge signal XEG indicating a timing of phase switching, in accordance with a plurality of signals CU, CV and CW induced when the motor is driven. The disk drive apparatus further has a drive voltage controlling unit for controlling, in accordance with the edge detection signal XEG, the maximum value of a drive voltage VS for driving said motor. This arrangement implements optimal motor control, while reducing circuit scale and cost and, at the same time, enhancing adaptability of the disk drive apparatus.

Abstract: A plurality type of adjustment data groups are stored in a memory for each of a plurality of adjustment items for adjusting a record signal waveform. The adjustment data group for each adjustment item is selected in accordance with identification information preset in accordance with a disk type and a record velocity magnification factor. The selected adjustment data groups are combined to form a record strategy. The record signal waveform is adjusted in accordance with the formed record strategy to record the record signal in an optical disk. It is possible to reduce the amount of adjustment data for the record signal waveform to be stored in the memory.

Abstract: An optical recording/playback apparatus of the present invention achieves proper focus control on a target recording layer of a single-layer disk or a multilayer disk. When the focus control is performed on the target information-recording layer of a recording medium, spherical-aberration compensation is first adjusted with respect to the thickness of a transmissive protection layer (cover layer) for the target information-recording layer. Alternatively, the adjustment may be made with respect to the average thickness of transmissive protection layers for the corresponding multiple information-recording layers. An objective lens is then moved along the optical axis to perform a focus-searching operation. In that case, the polarity of a focusing error signal and the level of a reflected-beam intensity signal generated as reflected-beam information are observed so as to perform the focusing operation.

Abstract: A data storage medium includes an optical information carrier comprising a spiral-wound polymer film. The central area of the data storage medium is provided with a recess whose periphery is formed by the innermost winding of the polymer film.

Abstract: The present invention relates to restrict a disk playing base plate against movement in back-and-forth directions, lateral directions and vertical directions relative to a housing by making use of the movement of a roller holder supporting a disk carrier roller. A pair of (i.e., left and right) side plates 11 of the roller holder has roller holder contact parts for restricting movement in the back-and-forth, lateral and vertical directions, and the top and bottom plates of the housing have housing contact parts corresponding to the roller holder contact parts. When a disk carrier roller is in a disk carrying position, the front part of the disk playing base plate is restricted against movement in the back-and-forth, lateral and vertical directions relative to the housing.

Abstract: A liquid crystal element is provided as a polarization plane rotating device between a laser beam source and a beam splitter. Light emitted from the laser beam source passes through the liquid crystal element and the beam splitter, and is converted into parallel light by a collimating lens. The collimated light is incident on a first light-selection device, is reflected at a flat first reflecting surface or a concave second reflecting surface, and is then incident on a super-resolution cut-off filter as a second light-selection device. The light having passed through the second light-selection device is incident on an objective lens, and is converged onto a recording surface. The selection of the reflecting surface of the first light-selection device is determined based on an operation mode of the liquid crystal element.

Abstract: An opical disc recording method, comprises the steps of: a) forming a record signal in accordance with input information; b) generating a recording laser beam modulated with the record signal; c) controlling a laser radiation time at a record power for a 16× or higher write-speed to be (n+K)T for a pit length nT, where n=three to eleven, K is a constant (0?K?1.6), and T is a unit time corresponding to a pit length or a land length at a write-speed; and d) radiating the recording laser beam alternately at the recording power for the controlled radiating time to form pits and at a non-recording power to form lands toward a record surface of a recordable optical disc.

Abstract: Header regions are formed by dividing a groove or grooves. Each of the header regions is provided with two ID sections G-ID1, G-ID2 storing address information and a track center detection mark section, arranged between the two ID sections, so as to be used for detecting the track center.

Abstract: A method of recording data optically to an optical disk having a plurality of sectors, in which each sector has a region to be recorded with data, the data is recorded in units of blocks, and the block includes a predetermined number of sectors and is a data unit including error correction codes. In recording data related to a content by dividing and recording the data in a plurality of sectors continuously, dummy data to be used for extracting a clock in PLL for data reproduction is recorded on a region adjacent before a sector from which data recording is started. The data related to the contents is recorded on sectors following the region recorded with the dummy data.

Abstract: An amplitude variation detection circuit that can reliably detect the mirror portion independently of the type of optical recording medium, as well as a type of information regenerating apparatus that contains said amplitude variation detecting circuit. Voltage division of top envelope signal Ste and bottom-hold signal Sbh of RF signal Srf is performed by voltage divider (16); then, after amplification by gain control amplifier (19) with a gain that corresponds to the type of optical disc (1), a prescribed offset is added by offset circuit (22) to the signal, and the resulting signal is input as mirror detection threshold signal Smt to comparator (24). The high-frequency noise component of bottom envelope signal Sbe of RF signal Srf is removed by low-pass filter (21); after amplification by gain control amplifier (20) with a gain that corresponds to the type of optical disc (1), the signal is input to comparator (24).

Abstract: In an optical pickup, an objective lens and an aberration correcting mechanism are held so that they can be moved together.

Abstract: A disc has a first area for recording musical data and a second area for recording information (first-area recorded-content information) related to the content of what is recorded in the first area. In each block constituting the second area, a character code of the block and language codes of all blocks are recorded in addition to the first-area recorded-content information. The disc is loaded into a disc player. When a system controller in the disc player reads the first-area recorded-content information from a designated block and displays it, the system controller counts and saves a read count corresponding to the language code of the block. When a new disc is played back, first-area recorded-content information is read from a block having a language code which has the maximum count and displayed in a language corresponding to the language code.

Abstract: An information playback apparatus of the present invention is provided with: a first detecting unit for supplying a difference between respective output signals optically obtained by a pair of detectors for reading the information of the first track; a second detecting unit for supplying a difference between respective output signals optically obtained by a pair of detectors for reading the information of the second track adjacent to the first track; a first demodulating unit for demodulating a detected signal supplied from the first detecting unit, a second demodulating unit for demodulating a detected signal supplied from the second detecting unit. A coefficient controlling unit extracts the crosstalk caused by the second track, which is included in a demodulation signal obtained by the first demodulating unit, from the same signal and controls a coefficient based on the extracted crosstalk, and cancels the crosstalk by the calculated coefficient.

Abstract: An optical recording apparatus obtains the most appropriate recording laser power state in real time according to an environmental mark-generation condition. When data is recorded (mark is generated) by emitting pulse-train-manner laser outputs to an organic-pigment recording medium, a first signal value corresponding to a first pulse in the pulse-train-manner laser outputs and a second signal value corresponding to second and subsequent pulses in the pulse-train-manner laser outputs are detected as a reflected-light information signal; the ratio thereof is obtained; and the obtained ratio and a reference ratio are used to generate a laser-power compensation signal to control the power of the laser outputs.

Abstract: An optical disc apparatus reads the address information from an optical disc which has tracks and track spaces formed between tracks. The apparatus has an optical head which irradiates the disc with light and includes tracking detectors, divided into a first detector and a second detector in a track direction, detecting the light reflected from the disc and outputting detection signals, an adjusting circuit which adjusts amplitudes of the first and second detection signals and outputs the signals at a position where the address information is recorded, a differential amplifying circuit which outputs the differential signal which is the difference between the adjusted first and second detection signals, and an address detecting circuit which detects the address information based on the differential signal. As a result, the optical disc apparatus accurately detects whether information is being recorded on a correct track and improves the reliability during recording.

Abstract: A disc cartridge having a disc accommodating chamber formed between an upper shell and an intermediate shell by overlaying the upper shell over an intermediate shell and a lower shell. The intermediate shell is rotatably supported by the upper and lower shells and an optical disc is rotatably accommodated in the disc accommodating chamber while part of the optical disc is exposed through shutter members on open portions of the intermediate shell.

Abstract: Embodiments include a method for adjusting the twist of an air bearing surface of at least one slider to substantially match a target values for twist, the at least one slider having a back surface opposite the air bearing surface, the back surface including two sets of diagonally opposite corner regions, with each set including one corner region adjacent to a leading edge of the slider and one corner region adjacent to a trailing edge of the slider. The method includes forming a first mechanical scribe on the back surface extending through at least a portion of the corner regions adjacent to the leading edge of the slider and forming a second mechanical scribe on the back surface extending through at least a portion of the corner regions adjacent to the trailing edge of the slider.

Abstract: An optical recording medium with a circular body including a substrate, a recording layer and a dielectric layer on the substrate, the circular body having a recording/reproducing area and a hub attached to a surface of the circular body. When the circular body stands vertically, the recording/reproducing area of the hub-attached surface is curved in a convex form, and the flexural amount is from 5 ?m to 100 ?m.