Abstract: A hybrid disc whose recordable-band grooves are wider and shallower than the pre-recorded ROM data pits. The ROM pits may be pre-recorded in ROM grooves that are at least as wide, but shallower than, the ROM pits. The ROM lands intervene between consecutive ROM pits, whether or not a ROM groove is provided. In the preferred embodiment, one beam of a dual beam apparatus records the ROM pits, while the other beam records the pre-grooves, and also records the ROM groove, if present. In most embodiments a thermal mastering process provides smooth feature surfaces to facilitate replication of the hybrid disc masters. The berms normally forming at the radial extremities of the pits and grooves in the masters, by thermal expulsion processes, may be reduced or eliminated by methods taught.

Abstract: A media player permits multiple compressed media files to be concurrently stored in memory interval to the media player. By concurrently buffering more than one compressed media file at a time, any mechanical disturbance that occurs during the playing of a file or between files will not cause a cessation of audio. Further, skipping ahead or in reverse is advantageously expedited.

Abstract: An optical disk has a groove in a recordable medium. The groove has a constant angular velocity wobble that is BPSK-modulated. Such a wobble provides timing and address information.

Abstract: The optical disk controller of this invention that reduces the frequency of output of status reports to relieve the burden of a system controller includes: a status generator for generating status reports each representing the operation state of the optical disk controller every sector of a disk; and a status sampling section for sampling the status reports at a set sampling interval. When a generated status report matches with “sampling abort” status stored in a sampling category storing portion, status sampling is aborted.

Abstract: A method and apparatus for suspending the operation of a rotating optical media player that uses simplified and efficient logic circuitry is described. When an operator initiates a pause operation, for example, by pressing a pause key, the current location of an optical pickup (e.g., a value of the current track ID) is stored. Then, a tracking servo loop is opened and a near zero offset is provided to the input of the tracking actuator. The condition of the optical disk system is then maintained in a “wait” state until the operator decides to end the pause process by selecting an alternate operation, such as “Play”, “Search”, or some other functions. When an alternate operation is received, the tracking servo loop is closed. The system then enters a search mode to reposition the optical head to the position indicated by the track ID, which was previously saved. Finally, the selected function command is activated.

Abstract: A pickup apparatus 1 is directed to an apparatus for optically reading-out information on a disk 3 arranged in a disk player, and comprises a pickup 11, an LD 13, a half mirror 15, a photo detector 17, and a pickup frame 19. The 11 is for irradiating a light on the 3 and for receiving the light reflected from the 3. The 13 is for transmitting the light to the 11. The 15 is a plate shape member for reflecting the light outputted from the 13 and for transmitting the light to the 11, that the light from the 11 permeate. The light permeating through the 15 incidents on the 17. The 11, the 13, and the 17 are fixed on the 19 at predetermined positions. A side part of the 15 is fixed to the 19 at three points by using an adhesive agent.

Abstract: A recording medium storing a write protection information, and a write protection method for protecting data recorded on a recordable and/or rewritable disc from unwanted overwriting or erasing. In order for write protection of a disc in a bare state that is usually used in a cartridge having a recognition switch for write-protection, such as a DVD-RAM, write protection information is recorded in a Lead-in area, a Lead-out area or a recording information area other than a user data area of the disc, and the data is protected from unwanted overwriting or erasing using the write protection information. Also, even though the write protection information stored on a disc does not match the state of a recognition switch of a case for write-protection, the data can be prevented from unwanted overwriting or erasing. Thus, the write protection can be ensured when a recordable and/or rewritable recording medium, such as DVD-RAM, DVD-R and DVD-RW, is used in a bare state.

Abstract: A method for protecting a phase lock loop (PLL) in an optical system is disclosed. The disclosed method will determine whether the currently reading data is erroneous and then maintain the frequency currently locked by the PLL circuit when the waveform lengths of the EFM signal in a detecting window contain at least one waveform length longer than 11T and at least one waveform length shorter than 3T. Otherwise, the PLL circuit will adjust the locked frequency according to the waveform length of the detected EFM signal so that the system clock frequency can be adjusted based on the locked one. In addition, when the optical system seeks tracks for reading required data under a constant angular velocity (CAV) modulation mode, the PLL circuit will increase the locked frequency gradually as the pick-up head moves towards the outer tracks of the optical disc, and decrease the locked frequency gradually as the pick-up head moves towards the inner tracks of the optical disc.

Abstract: An apparatus and method for providing continuous uninterrupted playback of a dual sided optical disk during side-to-side changing of the optical disk. The point at which a dual-sided optical disk will be switched between sides is determined. At some point prior to the switching of sides of the disk, a portion of the data at the end of the first side of the disk is transferred to a memory. During the switching of the disk to the second side, the stored data is read out from the memory to provide uninterrupted continuous playback of the optical disk.

Abstract: An optical scanning device scans an information track which is present on an information carrier. The scanning device includes a radiation source, a lens system with an optical axis for focusing a radiation beam supplied by the radiation source into a scanning spot on the information carrier, and a focusing actuator for displacing the lens system relatively to a basic part of the scanning device in a direction parallel to the optical axis. The actuator includes an electric coil which is arranged around the lens system and provided with a passage for a radiation beam path which extends in a direction perpendicular to the optical axis. The electric coil is provided around the lens system by means of a winding process, the passage being provided in the coil by bending the parts of the coil wires which are present near the radiation beam path, in a direction substantially parallel to the optical axis.

Abstract: A disc clamping apparatus includes an upper clamper holder, a lower clamper holder which is combined with the upper clamper holder, a clamper which is movably installed between the upper clamper holder and the lower clamper holder and clamps a disc that is disposed on a turntable, a first magnetic member installed between the upper clamper holder and the lower clamper holder, a second magnetic member installed on the turntable to face the first magnetic member so that a magnetic force operates between the first magnetic member and the second magnetic member to clamp the disc and an elastic member disposed between the upper clamper holder and the clamper so as to provide an elastic force to push the clamper against the disc. The disc clamping apparatus clamps discs having various thicknesses. Also, a clamping force of the disc clamping apparatus is changed in proportion to the thickness of the disc, and thus a proper clamping force can be applied to the disc based on the thickness of the disc.

Abstract: A method and associated apparatus for identifying, to manufacturing test equipment, copy protection information contained on a compact disc (CD). The method includes adding data in standardized industry formats to unused sectors of a CD and providing the capability to test equipment to read the data. The added data is unreadable and ignored by conventional compact disc readers and compact disc drives. The added data is defined by manufacturers and users of copy protection techniques. Additional copy protection verification can be accomplished by using specialized verification tools.

Abstract: An optical device is provided which has a light converging unit for converging the light illuminated on a magneto-optical recording layer of an optical recording medium and a magnetic field generating unit provided on the light converging unit towards the optical recording medium. The diameter of the light beam radiated on the magneto-optical recording layer of the optical recording medium is controlled by a light transmitting hole of the magnetic field generating unit. The light beam illuminated on the magneto-optical recording layer of the optical recording medium is not fluctuated in diameter so that it is possible to produce a magnetic field at a low power consumption. In addition, the magnetic field generating unit is not liable to be ruptured. There is also provided a recording and/or reproducing apparatus employing this optical device.

Abstract: An optical pick-up device includes a lens that focuses light onto a recording medium, a lens holder that holds the lens, a suspension holder that supports the lens holder disposed opposite a distal end of the lens holder, a frame formed so as to be disposed opposite both lateral surfaces of the lens holder and the distal end of the lens holder, the frame supporting the suspension holder, a plurality of elastic supports that movably support the lens holder, a distal end of the elastic supports mounted on the suspension holder, and an actuator that drives the lens holder, wherein a plurality of projections is provided on at least one of the lens holder, the frame and the suspension holder, the projections acting as stoppers that restrict a rotation of the lens holder so as to prevent excessive deformation of the elastic supports.

Abstract: Disclosed is a lens for light collection for total reflection for a front monitor photodiode (PD) in an optical pick-up device. The optical pick-up device includes a light source provided with a holographic unit adapted to diffract a light beam, an optical disc arranged in front of the light source and adapted to allow data to be written thereof or to be read therefrom, a monitor photodiode arranged in front of the light source in a diagonal direction with respect to the light source, the monitor photodiode serving to monitor a laser power of the light source, and a lens for light collection arranged between the light source and the monitor photodiode and adapted to converge a first-order diffracted beam outputted from the holographic unit and to apply the converged first-order diffracted beam to the monitor photodiode.

Abstract: A predetermined electric current is supplied to coil by changing a pulse width of a voltage applied to the coil according to a current instruction value. An electric current which flows through the coil is detected; the thus-detected current value is compared with the current instruction value; the voltage applied to the inductance device is turned on/off according to the comparison result; and an off time for which application of the voltage to the coil is interrupted is controlled according to the current instruction value.

Abstract: When a medium is stored or removed manually, all slots must be checked to find any change in medium information, and as a result, updating medium storage information takes a long time. A medium controller, having a plurality of media and a medium transfer unit to take a medium in and out of storage and move the medium for reading or writing information, includes slots in which media are stored, sensors each mounted in a slot for detecting whether there is a medium in the slot; a sensor manager for holding a log of the status transitions of the sensors in a period when media are likely to be stored or removed manually and deciding the status transitions; and a part for reading information. Only when it is decided from a decision result of the sensor manager that the medium has been replaced, the media controller causes the part for reading medium information to read medium information in order to update the medium storage information.

Abstract: There are provided an information write device and an information read device enabling to generate highly accurate contrast signals. When a main light spot Pc is located at the center of the a groove G, the light spot Pc and sub light spots Psa, Psb are each adapted to radiate a disc DSC such that the sub light spots Psa, Psb radiate positions displaced from the center of the land L. The reflected beams of light from the disc DSC caused by the radiation with the light spots Pc, Psa, Psb are detected to generate push-pull signals each corresponding to the light spots Pc, Psa, Psb, respectively, in accordance with each of the detected signals. Furthermore, a signal to be obtained by amplifying an addition signal, given by adding the push-pull signals each corresponding to the sub light spots Psa, Psb, with a predetermined amplification factor K/n, and a push-pull signal corresponding to the main light spot Pc are added to thereby generate a contrast signal.

Abstract: An apparatus and a method for compensating a tilt of an optical recording medium comprising a servo error generating unit for generating RF(Radio Frequency) signal and a servo error signal from an electric signal outputted from an optical pickup unit, a servo control unit for generating a focus operation signal and a tracking operation signal by signal-processing separately a focus error signal and a tracking error signal outputted from the servo error generating unit, performing a focus search at a certain position in order to detect tilt, and generating a tilt operation signal by detecting tilt, a focus servo operation unit for operating a focus actuator inside of the optical pickup unit by receiving the focus operation signal outputted from the servo control unit, and a tilt operation unit for compensating tilt by controlling the pickup unit in accordance with the tilt operation signal outputted from the servo control unit.

Abstract: An optical head has achromatic lenses which a blue or blue-violet laser beam from a laser diode strikes, object lenses for condensing the laser beam passing through the achromatic lenses on an optical disc, lens holders and for holding the achromatic lenses and the object lenses so that their optical axes coincide, and actuators and for moving the lens holders in the focus direction and/or tracking direction of the optical disc. The lens holders are fixed to each other and the lenses are moved as one part by the actuators.