Abstract: A pickup for a magneto-optical recording medium is provided, which improves quality of reproduced signals by eliminating a phase difference between the polarizations and is capable of coping with magneto-optical recording media of different recording/reproducing systems. A return light beam of light reflected by a magneto-optical recording medium is polarized and separated into ± first-order diffracted lights through a light-branching diffraction element provided between a light source and an objective lens. The ± first-order diffracted lights are compensated for their phases through first and second phase compensation elements so that there is no phase difference between the polarizations, and are, further, polarized and separated through the first and second polarization/separation elements, and are received by first and second light detectors.

Abstract: There is provided an optical pickup device comprising a laser light source for emitting a laser beam, an object lens for focusing the laser beam onto the recording surfaces of layers 0 and 1 of an optical disk and condensing the laser beam onto the recording surfaces, photodetectors for receiving the laser beam reflected by the optical disk, and a diffraction grating for diffracting a part of the reflected laser beam toward the photodetectors, wherein data can be simultaneously written to layers 0 and 1. The photodetector detects the reflected light from layer 0 after being refracted by the diffraction grating, and detects the reflected light from layer 1 without being refracted, so that the data of layers 0 and 1 can be simultaneously read. Thus, data can be simultaneously read from and written to the recording surfaces of a plurality of layers of an optical disk.

Abstract: A reproduction apparatus is provided for reproducing information recorded on an information recording medium. The information recording medium includes a data area for recording user data; and a defect management area for recording a defect list for managing N number of defect areas existing in the data area, where N is an integer number satisfying N?0. The defect list includes two or more blocks and a header located at a fixed position in the defect list. The defect list further includes N number of defect entries, located subsequent to the header, including position information on the respective positions of the N number of defect areas; and an anchor located subsequent to the defect entries.

Abstract: A disc with a temporary defect management information area and a defect management area includes a defect management area that is present in at least one of a lead-in area, a lead-out area, and an outer area, a temporary defect information area which is formed in the data area and in which temporary defect information is recorded, and a temporary defect management information area which is present in at least one of the lead-in area, and the lead-out area. Accordingly, it is possible to record user data in a recordable disc, especially, a write-once disc, while performing defect management thereon, thereby enabling efficient use of a defect management area having a limited recording capacity.

Abstract: An apparatus for controlling a monitor photo diode (PD) of an optical pickup system monitors an optical power signal output for writing data on or reading data from a disk. The apparatus includes a comparator which compares a voltage signal corresponding to the optical power signal output from the LD with a predetermined reference voltage signal, and a gain selector which selectively issues a gain output from the comparator depending on the type of the optical power signal output from the LD.

Abstract: A recording/reproducing apparatus includes a cartridge holder which is rotatably provided on a chassis, into which a disc cartridge enclosing a magneto-optical disc is inserted, and which holds the inserted disc cartridge, an optical pickup that irradiates laser light onto the magneto-optical disc, a magnetic head that is provided on the upper surface side of the cartridge holder facing the optical pickup and that is moved between a lowered position close to the optical disc and a raised position away from the magneto-optical disc, at least one first sliding member that is movably provided on the cartridge holder, a head raising/lowering mechanism that moves the magnetic head between the upper position and the lower position by moving the first sliding member, and a driving mechanism that is disposed on a lower surface side of the chassis, engages the sliding member, and moves the first sliding member.

Abstract: A method for opening/closing a disk tray of a disk drive. The method includes the steps of when a first event occurs, sending a load/unload command to the disk drive, to which the disk drive responds with a second or third event, and resends the load/unload command to the disk drive when the disk drive responds to the previous load/unload command with the second event.

Abstract: A method and apparatus for controlling read-out and/or synchronization between an external magnetic field and written data during a reading operation from a magneto-optical recording medium includes generating a pulse in a reading signal in a read-out layer by copying a mark region from a storage layer to the read-out layer upon heating by a radiation power and with the aid of the external magnetic field. The waveform of the reading signal is analyzed, and the analysis result is used for correcting a phase deviation and/or for controlling a copy window size of the mark copying. Phase errors may thus be corrected for any size of the copy window. Even small changes in the copy window can be detected and corrected.

Abstract: A method of, and an apparatus for detecting a radial tilt of a disc. Phases of summed signals obtained from signals that external light-receiving units of an octant photo diode receive are compared to generate an external phase comparison signal Do. Phases of other summed signals obtained from other signals, that internal light-receiving units of the octant photo diode receive, are compared to generate the internal phase comparison signal Di. The radial tilt is detected based on the internal and external phase comparison signals Di and Do obtained when a laser beam crosses a track formed the disc. Thus, the radial tilt can be more precisely detected.

Abstract: There are provided: an optical pickup feed mechanism (12) that detects a disk signal; a disk loading mechanism (11) that feeds a disk D by means of a loading roller (11b) that is driven by a loading motor (11a); a mechanism control section (20) that controls drive of the loading motor (11a); and an authentication control section (30) that authenticates the authorized user and outputs a disk ejection instruction to the mechanism control section (20) if the registered password and disk ejection instruction are input. The authentication control section (30) is provided with a time setting section (36) that stores a set time length in memory (32), a timer (37) that measures time, and a time decision section (38) that determines lapse of the set time length in accordance with the time length stored in the memory section (32) and the time measured by the timer (37).

Abstract: A pinned magnetic layer 20 and a free magnetic layer 26 include a magnetic portion 17 and a magnetic sublayer 22, respectively, each comprising a half-metallic ferromagnetic alloy. Since each of the magnetic portion 17 and magnetic sublayer 22 comprising the half-metallic alloy layer has a larger value ? and a larger resistivity ? compared to the conventional CoFe alloy or the like, the change in resistance (?R) can be increased, and the rate of change in resistance (?R/R) can be appropriately improved.

Abstract: Prior to recording/reproducing information to/from an optical disk rotationally driven by a spindle motor, an optical pickup is moved to a plurality of measuring positions set beforehand in a radial direction of the optical disk. A relative tilt between the optical disk and the optical pickup is detected with the spindle motor being rotated so that a linear velocity at each of the measuring positions equals a linear velocity upon actually recording or reproducing the information thereat. The tilt detected at each of the measuring positions is stored as tilt detection data corresponding to each of the measuring positions.

Abstract: An optical pickup includes a diffraction grating partitioned into three areas, in which the phase of periodic grating groove structure in an area is successively shifted from that in the adjacent area by 90°. In the generation of a differential push-pull signal, an amplification factor K for sub push-pull signals is varied depending on the type of the optical disk. By such composition of the optical pickup, amplitude deterioration of the tracking error signal accompanying displacement of the object lens is reduced.

Abstract: A storage device includes a storage medium and a probe having plural tips. The storage medium has a surface in which storage cells are to be formed. The tips of the probe form plural perturbations in the surface in at least one of the storage cells for representing a data bit.

Abstract: A front monitor-type optical pickup apparatus is composed of a window 10w for taking in a laser light beam, and a housing 10 for housing a front monitor detector 9 so as to face the window 10w. In the housing 10, the position of the front monitor detector 9 is adjustable. The optical pickup apparatus makes it possible to eliminate dispersion in quantity of incident light upon the front monitor detector attributed to component and assembly dispersion.

Abstract: An actuator of an optical disk system and an apparatus producing a signal for driving the actuator, the actuator including a light source, with which information is recorded on or reproduced from an optical disk surface. In the actuator, an inner focusing coil and an outer focusing coil are installed near an inner boundary and an outer boundary, respectively, of the optical disk surface. A first signal wire is connected to a first port of the inner focusing coil and transmits an inner coil signal. A second signal wire is connected to a first port of the outer focusing coil and transmits an outer coil signal. A common signal wire is connected to a second port of the inner focusing coil and a second port of the outer focusing coil and transmits a common reference signal. Thus, a simple, inexpensive 8-wire actuator can be obtained.

Abstract: A disc conveying apparatus includes a first conveyor unit having a plurality of rollers which are arranged along a conveying path of a disc-shaped recording medium with gaps therebetween, which move in a direction away from the conveying path and rotate individually, and which convey the disc-shaped recording medium by successively rolling on a peripheral surface of the disc-shaped recording medium to pass the disc-shaped recording medium from one to another, a second conveyor unit which faces the first conveyor unit across the disc-shaped recording medium being conveyed, which is oriented along the conveying path, and which retains the disc-shaped recording medium between the first conveyor unit and the second conveyor unit, and a control unit which detects the position of the disc-shaped recording medium and controls the rotation of the rollers on the basis of the movement of the rollers in the direction away from the conveying path.

Abstract: A beam shaping element includes a set of diffraction gratings on each surface thereof, in such a manner that intervals between the gratings farer from a vicinity of an optical axis and nearer to a periphery are narrower, wherein each interval between the respective gratings monotonously increases or monotonously decreases along a direction in which each grating-shaped pattern extends. According to the arrangement above, it is possible to correct displacement of a light emitting point of a light source by simply performing a positional adjustment within a plane that is orthogonal to the optical axis. Thus, it is possible to provide the beam shaping element that enables to correct the displacement of the light emitting point of the light source simply by performing positional adjustment in the plane vertical to the optical axis, thereby making it unnecessary to perform positional adjustment along the optical axis direction, and to provide a light source unit and an optical pickup using the beam shaping element.

Abstract: A driver IC 1 has a bias terminal 20a via which a bias voltage fed from a microcomputer 2 to drive and control a loading motor 4 is fed in and a bias terminal 20b via which a bias voltage fed from a DSP 3 to drive and control a focus coil 5, a tracking coil 6, a sled motor 7, and a spindle motor 8 is fed in.

Abstract: In a data slicer and data slicing method for an optical disc system, the data slicer for converting an analog input signal into a digital signal includes a comparator, a duty detector, and a low pass filter. The comparator compares the analog input signal with a feedback signal to generate the digital signal. The duty detector detects the duty of the digital signal. If the detected duty is longer than a preset duration, the duty detector converts the detected signal into a signal having the preset duration, and outputs the converted signal. The low pass filter integrates the output signal of the duty detector to generate the feedback signal.