Abstract: A rotation control method controls rotation of a CAV system recording medium which has a plurality of zones divided in a radial direction thereof. The rotation control method detects a state within a memory which temporarily stores write data to be written on the recording medium and/or read data read from the recording medium, and switches and controls a rotational speed of the recording medium based on the detected state of the memory, depending on an area which is accessed of a plurality of areas of the recording medium dividing the recording medium in the radial direction thereof.

Abstract: A method of recording information in which each recording mark is formed in a recording medium, by irradiating a pulse chain of an energy beam including a first pulse, a middle pulse chain, a last pulse and a negative pulse following the last pulse. The adjusting average power of the first middle, last and negative pulses to designated power levels of the first, middle, last and negative pulses recorded in a control data zone.

Abstract: An optical pickup unit includes a light source emitting a light beam, an objective lens focusing the light beam onto an information recording medium, a light detection part receiving the light beam reflected from the information recording medium, and a light blocking part selectively blocking a part of the light beam with respect to a radial direction. The light blocking part is provided in an optical path of the light beam centered on an optical axis.

Abstract: Information is recorded/reproduced by focusing a light beam in/from an optical recording medium capable of forming therein marks for information recording in a plurality of three-dimensional directions including an arbitrary directions and at least depth direction. Specifically, the optical beam is sequentially focused at a recorded mark position adjacent an optically recorded mark position, at which a recording/reproducing operation is started, in any directions regardless of the directionality of the plurality of three-dimensional directions, to cause the focused position of the light beam to describe a predetermined locus having a predetermined rule to rapidly and continuously record/reproduce the information.

Abstract: The present invention is to disclose a SIL near-field flying head flying state control structure in which the SIL is installed in a lens holder that can be biased. The lens holder includes three detection points spaced around the SIL for detecting the distance between each detection point and an optical disk, and a number of single-axis displacement devices for controlling the corresponding lateral side of the lens holder to move axially relative to the optical disk. A server can control the single-axis displacement devices to adjust the posture of the lens holder subject to the distance between each detection point and the optical disk measured, keeping the parallelism between the SIL and the optical disk within a predetermined level.

Abstract: An optical pickup apparatus includes a light source and a light detector provided on a stem for detecting source emitted light reflected by an optical recording medium; and a light separating device, having first and second areas, for separating light incident thereon into a plurality of light components respectively directed in prescribed directions. The light detector includes a light receiver, divided into first and second light receiving regions for receiving the light components detected by those first and second areas. The first and second light receiving regions are located in a predetermined orientation determined in part by a light emitting point of the light source and a focal point on the light detector. The stem material and the wavelength emitted by the light source are selected to limit movement of that focal point in that orientation in response to temperature change of the apparatus.

Abstract: A method of recording data on a recording medium includes mapping the data to a set of write symbols wherein each write symbol represents more than one bit of the data. The set of write symbols is defined by defining a set of variable write parameters; generating a plurality of candidate write symbols that specify different values for the variable write parameters; generating a plurality of readout waveforms produced by the plurality of candidate write symbols; analyzing the readout waveforms to determine desired set of readout waveforms; and selecting selected ones of the plurality of candidate write symbols that correspond to the desired readout waveforms to be included in the set of write symbols. The data is written to the medium using the write symbols.

Abstract: In a holographic digital data storage system, a light source generates a reference beam, a holographic optical element saves a plurality of interference patterns between the reference beam and a plurality of beams of specific sizes and a beam splitter splits each reproduced beam into a holographic signal beam and a holographic reference beam. A medium records an interference pattern between the holographic reference beam and the holographic signal beam and reflecting the holographic reference beam to generate a reflective information beam and, if only the holographic reference beam is illuminated, a displaying means displays a holographic reproduced beam for the holographic signal beam and detecting the reflective information beam.

Abstract: A recordable optical information recording medium having an address t for each sector, comprises: an area A1 starting from an address t1 to which access is made only when a recording apparatus performs recording operation; an area A2 starting from an address t2 to which access is made either when the recording apparatus performs the recording operation or when the recording apparatus performs reproducing operation; and an area A3 starting from an address t3 to which access is made either when either the recording apparatus or a reproducing apparatus performs recording or when either the recording apparatus or the reproducing apparatus performs reproducing. The addresses t are set consecutively with respect to a physical arrangement of the sectors in each of the areas A2 and A3, and the area A1 has at least one inconsecutive part at which the addresses t are not consecutive with respect to the physical arrangement of the sectors.

Abstract: In PLL circuits for reproducing a channel clock in synchronism with data read from a disk-shaped recording medium driven for rotation, the frequency dividing ratio of frequency dividers provided in desired signal paths is made changeable according to the reproduced signal format of a CD reproduced signal or a DVD reproduced signal, for example. Although the frequency of the channel clock in synchronism with the reproduced signal differs in different signal formats, the above configuration makes it possible to reproduce the channel clock properly in accordance with a plurality of signal formats only by the operation of changing the frequency dividing ratio in a PLL circuit.

Abstract: Software is securely distributed with limited usage rights. The software may be an executable program and/or one or more data files such as image or multimedia data files. The software includes an access control object which prevents at least some usage of the software without use of a first access control code. The first access control code is produced based on selected information characteristic of the user's computer system. The access control code is produced in a server computer to which the user directs a request for the access control code. The user makes a payment to receive the access control code, which is then downloaded to the user's computer system.

Abstract: An information recording device for writing information in a circumferential direction of a disk-type recording medium, with a substantially constant linear density.

Abstract: Data is written on a plurality of data tracks on an optical disk by a plurality of laser beams. The spots illuminated by the beams are spaced apart to prevent thermal interference. The spots are aligned along a line at an angle to the tangent of the data tracks. The angle of the line of spots is determined by an equation using variables that include the track pitch, the minimum distance between spots and the difference in track numbers between tracks being written.

Abstract: An optical pickup device is adapted to read information signals from optical recording media of two different types such as a “DVD” and a “CD” for which two light beams with different wavelengths are used and comprises a photodetector having a single light receiving section that can be shared by optical recording media of two different types. Both the light beam reflected from the signal recording surface of the “DVD” 106a and the light beam reflected from the signal recording surface of the “CD” 106b are diffracted by the diffraction element 6 and focussed to a same spot on the light receiving surface of the photodiode of a photodetector 7.

Abstract: A method and apparatus for providing a plurality of aligned instructions from an instruction stream provided by a memory unit for execution within a pipelined microprocessor is described. The microprocessor comprises a prefetch buffer, whereby the prefetch buffer stores prefetched instructions and additional information about the validity and size of the prefetch buffer. The method and apparatus use the prefetch buffer to buffer a part of an instruction stream. The actually aligned instruction stream is issued from the prefetch buffer or directly by instructions fetched from the memory, or from a combination of prefetched instructions and actually fetched instructions.

Abstract: An ATIP (absolute time in pre-groove) bit data generator free from an uneven duty cycle. The ATIP bit data generator includes an analog processor, a high-frequency clock generator, a first decoder, a sync pattern detector, and a second decoder. The analog processor receives a signal generated from an optical pickup, and further processes the signal to generate an ATIP FM signal. The high-frequency clock generator provides a high-frequency clock using the ATIP FM signal as a reference signal. The first decoder receives the ATIP FM signal and the high-frequency clock and generates bi-phase data. The sync pattern detector receives the bi-phase data and the high-frequency clock, and generates a sync indication signal. The second decoder counts the pulse number of the high-frequency clock for each counting cycle, and the counting cycle includes a plurality of half periods of the ATIP FM signal.

Abstract: A system and method for dynamically re-calibrating an optical disc drive during operation is provided. The optical media includes a pitted premastered area that cannot be overwritten and a grooved user-writeable area that can be overwritten. The system can attempt several increasing levels of effort to recalibrate the disc drive until the disc drive reaches a desired level of performance, or the recalibration effort levels are exhausted. During each level of recalibration effort, various calibration values are determined for the optical media and the servo actuator, along with a notch frequency for a notch filter; a focus actuator offset; a tracking actuator offset; a focus control loop gain; and a tracking control loop gain. The optical media disc is divided into zones, and zone calibration tables for each of the zones are generated. Each zone is recalibrated using the corresponding zone calibration table.

Abstract: A diffraction type lens in an optical pickup apparatus for recording and reproducing two or more kinds of optical recording media is constituted by a substrate having one surface formed with a zone plate exhibiting a smaller converging action with respect to a wavelength ?1 of light and a greater converging action with respect to a wavelength ?2 of light, and the other surface formed with a zone plate exhibiting a smaller converging action with respect to the wavelength ?2 of light and a greater converging action with respect to the wavelength ?1 of light. The substrate is transparent to the wavelengths ?1 and ?2 of light.

Abstract: An optical disc apparatus which is compatible with a compact disc (CD) and a Digital Versatile Disc (DVD) has a configuration of an optical pickup which performs a scanning operation in a focus-on and track-off state to read signals from an optical disc; an RF amplifier which, on the basis of the read signals, produces binary track-cross signals and binary mirror signals; a first edge counter which counts the number of the binary track-cross signals; a second edge counter which counts the number of the binary mirror signals; and a central processing unit (CPU) which discriminates between a CD or a DVD on the basis of a ratio between the number of the binary track-cross signals and the number of the binary mirror signals.

Abstract: An information recording apparatus includes a data writing part that writes data transferred from a host computer onto a data-recordable recording medium, a data writing pause part that pauses writing of the data by the data writing part, a data writing rate change part that changes a writing rate at which the data writing part writes the data, a data writing restart part that restarts the writing of the data, and a data writing control part that controls the data writing pause part, the data writing rate change part, and the data writing restart part.