Abstract: A method and apparatus for magnet-optical recording are provided that can reduce heat in pulse driving of a magnetic head coil of a magnet-optical recording apparatus. Data inversion detection means 41-44 generates a signal TRDET that becomes the high level when a magnetic inversion of data occurs and becomes the low level when no magnetic inversion of data occurs. Means for reducing an exciting energy 45-47 use this signal TRDET so as to generate a strobe signal STRB that has a short period of the high level when a magnetic inversion of data occurs and a normal period of the high level when no magnetic inversion of data occurs. The magnetic head coil is excited during a period in which the strobe signal STRB is the high level, so that the pulsed magnetic field is generated, which is applied to a magnet-optical recording medium.

Abstract: A clock generator in a recorded information reproduction apparatus for reproducing recorded information from a recording medium includes a pickup that produces a reading signal by reading a recording track of the recording medium. The reading signal is sampled by a sampling circuit at timing corresponding to a clock signal to produce a reading sample value sequence. A crosstalk removing circuit removes crosstalk components which are present in recording tracks adjacent to the recording track read by the pickup from the reading sample value sequence and produces a crosstalk-removed reading sample value sequence. A phase detecting circuit detects a phase error existing in the reading signal based on the crosstalk-removed reading sample value sequence. A clock signal generating circuit generates the clock signal based on the phase error.

Abstract: A device for reading or writing on optical recording media with disk type recognition capability has an optical scanning device and a focus regulating circuit. The object of the invention is to provide a device of this type which can reliably recognize in a short time the type of the recording medium inserted into the device. Another object of the invention is to provide a corresponding process. These objects are attained in that the disk type recognition capability includes a mirror signal generator, a threshold value generator, a counter and an evaluation unit. The process is based on the utilization of a mirror-signal value of the device for disk type recognition.

Abstract: A tilt detection system includes an optical disk having a series of data recorded therein, the series of data having a pulse width smaller than the minimum pulse width of data recorded in an ordinary optical disk; a reproducing part reproducing a signal from the optical disk by emitting a light beam onto the optical disk; and a tilt detecting part detecting a tilt of the light beam with respect to the optical disk based on a reproduced RF signal provided by the reproducing part when the series of data having the smaller pulse width is reproduced.

Abstract: Apparatus for providing fine search in a sled movement mechanism employing a stepping motor by controlling the speed with which the head jumps in succession to next neighboring tracts on a disc and by causing pickup movement accurately for a distance corresponding to the distance of movement of the objective lens to realize the fine search in the sled movement mechanism employing the stepping motor. Also, the distance of head movement in the radial direction of the disc can be prescribed and, upon interruption of the head jumping operation, the head can be subsequently transported a distance corresponding to the target number of track jumps.

Abstract: A tuned circuit is used to detect wobble clock inversions. The tuned circuit reacts to a wobble inversion with a change in amplitude that may be detected by a threshold detector. A bandpass tuned circuit is used to detect wobble clock inversions. The output of the bandpass tuned circuit is input to a saturating high-gain amplifier such as a comparator. The output of the saturating high-gain amplifier reacts to wobble inversions with a half-cycle that has an increased duration as compared to half-cycles without wobble inversions.

Abstract: An optical pickup apparatus having compatibility with a recodable compact disk (CD-R) and a digital video disk (DVD), which uses a wavelength of one of a first light beam and a second light beam according to the recording medium to be used. In the optical pickup apparatus, laser light sources emit a first light beam having a relatively shorter wavelength for the. DVD and a second light beam having a longer wavelength for the CD-R, respectively. An objective lens has a predetermined focal length in accordance with the position of an information recording surface in the DVD. An optical path control unit controls the path of light beams so that the light beam emitted from one of the laser light sources is directed to the objective lens and the light output from the objective lens is directed to the optical detection unit.

Abstract: A video signal recording apparatus using an information recording medium, having: a unit for identifying and detecting a WO type information recording medium and a rewritable type information recording medium; a control unit for each of the WO type information recording medium and the rewritable type information recording medium; and a display apparatus for displaying a detection result of the detecting unit. In the video signal recording apparatus using the information recording medium, file management information to form a directory is recorded as intermediate information onto the information recording medium.

Abstract: A method to produce improvements in the shape of three-dimensional features displayed in optical recording structures, particularly in such structures displaying features of differing dimensional characteristics. The shape improvements include reductions in berm height and width, dual level data marks and tracking guides, and land areas projecting above or into the surface of the recording structure. The method includes dual and/or dithered beam writing onto the structure and improved composition of the active layer of the structure.

Abstract: A drive device has a feed mechanism that causes a control object to move in order to control the positioning of the control object, a motor that serves as the drive source of said feed mechanism, and a control means that controls this motor. The control means has an operation history memory unit that stores the operation history of whether the motor is doing an initial start or a restart, and a command selection unit that selects control commands and outputs them to said motor based on information stored in said operation history memory unit. Because intermittent operation that repeatedly drives and stops the motor occurs when there is a restart, the thermal shutdown associated with overheating of the driver IC is avoided, and any difference between the feed amount due to the control means and the actual feed amount can be prevented.

Abstract: The present invention relates to a device for reading from and/or writing to optical recording media having a scanning unit, which is equipped with at least two detector units each having a plurality of detector elements, and also an evaluation unit, each of the detector elements being connected to the evaluation unit by means of a line. The object of the present invention is to simplify the structure of a device of this type. This object is achieved by virtue of the fact that detector elements of different detector units are each connected to the evaluation unit via a single line. The device according to the invention is advantageously a device which can read from and/or write to not only optical recording media which correspond to a CD standard but also those which correspond to a DVD standard.

Abstract: An optical head includes a laser source (11) irradiating the laser beam having a wavelength not longer than 500 nm, a collimator lens (13) for collimating the laser beam to the parallel rays, an optical beam shaping system (14, 15) that adjusts the cross sectional shape of the beam from the collimator lens, an objective lens (16) that converges the beam on an optical information medium. The optical head has a relationship between a focal length fCL of the collimator lens and a magnification M of beam shaping satisfies the following equation.

Abstract: A slider for an optical head for signal recording and/or reproduction on or from a recording medium which, even if reduced in size, assures optimum signal recording and/or reproduction on or from a recording medium, and which may be produced readily. The slider for the optical head includes a slider member for floating and running over a recording medium during recording and/or reproduction of information signals for the recording medium, an optical lens bonded to the slider member and a magnetic field generating unit provided on a surface of the slider member carrying the optical lens facing the recording medium. The slider member is formed with a terminal groove opened in a its surface facing the recording medium and in its lateral surface, with an electrically conductive material being charged in the terminal groove. The electrically conductive material charged forms a terminal electrically connected to the magnetic field generating unit.

Abstract: The invention provides a method and apparatus for generating delays to shift edges of an EFM data stream from an EFM modulator for a CD-R and CD-RW write encoder. EFM data pulse edges may be delayed in increments of about {fraction (1/32)} Tefm where Tefm is the code rate clock of an EFM data stream output. The delays are generated by a synthesizer running at four times the EFM code rate. The synthesizer may be built using a four-stage ring oscillator. Delays are selectable based upon the write strategy matrix in coarse increments of ¼ T and fine increments of {fraction (1/32)} T. For the coarse delay, the EFM data may be passed through a four stage shift register running at Fsynth, where Tefm=4×Fsynth, allowing for a coarse delay selection of ¼ Tefm.

Abstract: A method of writing data on a disk includes the step of writing a first subset of data on a disk such that an amount of write power to write the first subset of data is adjusted in a closed-loop operation. A write-power signal representing the amount of write power to write the first subset of data is measured. After a write interruption, such as from a buffer under-run, a second subset of the data is written on the disk in an open-loop operation using the measured write power, such that the second subset of data is adjacent to the first subset of data.

Abstract: A magneto-optical read head for detecting magnetic transitions representing data stored in a magnetic recording medium as a sense layer having an optical property that is magnetic field-dependent, two magnetic shield layers respectively disposed on opposite sides of the sense layer and allowing magnetic flux from substantially only one of the magnetic transitions to interact with the sense layer at a time, with one of the magnetic shield layers being transparent at a wavelength allowing light at that wavelength to enter into and exit from the sense layer.

Abstract: A storage apparatus uses a light beam to reproduce information from a recording medium having an information region with a recording format which includes a header including position information and a recording field including a data field for recording data. The storage apparatus is provided with a light source for emitting the light beam, and a control section for controlling a power L2 of the light beam in a vicinity of a start of the recording field to become higher than a power L3 at the data field of the recording field.

Abstract: The present invention writes location information on representative audio sections, each being specified within an audio track by a user, for audio tracks recorded in a high-capacity storage medium, and, if requested, reproduces representative audio sections only using the written location information, thereby helping a user find a desirable audio track easily and quickly among a lot of recorded audio tracks.

Abstract: Recording/reproducing information signals to/from a recording medium appropriately even though the clearance from the signal recording surface of the recording medium to an optical head slider becomes significantly small. An optical head slider 10 includes a sliding member 11 which is floated and slides on a recording medium 4 at the time of recording/reproducing signals to/from the recording medium 4, a hemispheric objective lens 12 which is bonded to the sliding member 11, and a magnetic field generating means 16, which is mounted to the bottom of the sliding member 11 which faces the recording medium 4. The sliding member 11 is made of the same material as that of the optical lens 12, and a flat surface of the optical lens 12 is bonded to the top surface of the sliding member 11.

Abstract: An optical disc drive has a spindle motor for rotating an optical disc; an optical pick-up which can move at least in a radial direction of the optical disc; a sensor for detecting the rotation of the motor; and a spindle servo for controlling the rotation number of the spindle motor based on signals from the sensor. This spindle servo is adapted to be operated at the time of changing the rotation number of the spindle motor, e.g. at the time of changing rotation speed of the spindle motor in multiple steps given by integral multiples of 1 or at the time of changing rotation speed when the optical pick-up moves in the radial direction of the optical disc. According to this optical disc drive, it takes a relatively short time until the rotation speed of the motor reaches the target rotation speed and its rotation becomes stable.