Abstract: Disclosed herewith is an information reproducing method for realizing significant expansion of disk capacity and processing signals having different minimum run lengths, as well as an optical disk drive that uses the method. To achieve the above objects, a PRML method is used. According to the method, a compensation value is added to an initial target value decided by a convolution operation of NN bits according to a bit array consisting of N bits (N>NN) to obtain a new target value, which is then compared with each of reproduced signals sequentially to select a bit array in which the error between the reproduced signal and the target signal is minimized most likely, then the selected bit array is binarized.

Abstract: A system, method, computer program and apparatus for providing regulating signals for regulating the position of an objective lens relative to a track on a disk. The regulating signals are obtained in response to an access request specifying an access target region on the disk. The tracks of a disc are divided into a plurality of zones, each zone having associated signal regulation information. In response to an access request, the signal regulation information for the zone containing the access target region is used to regulate the position of the objective lens.

Abstract: A liquid crystal lens element having a lens function is provided, which is small sized without having moving part, and which can stably carry out correction of spherical aberration containing a power component corresponding to focal point change of incident light.

Abstract: An apparatus and a method determine an area of an optical disc in which an inner area and an outer area of the optical disc having an absolute time of 99 minutes are distinguished from each other by referring to a number of ATIP syncs. The method includes counting the number of ATIP syncs for one rotation of the optical disc at a current position of a pickup when ATIP information recorded on the optical disc indicates that the pickup is currently present in an area of the optical disk that is greater than or equal to 95 minutes; and determining the current position of the pickup by comparing the number of counted ATIP syncs with a reference number of ATIP syncs. Accordingly, time spent determining the area of an optical disc and accessing the optical disc is reduced.

Abstract: A focusing controller and the method thereof for an optical disk drive. The focusing controller includes a filter, a coupler and a focus compensator. The filter filters out a high-frequency component of the track error signal and derives an adjusted signal, while the coupler eliminates the adjustment signal from the focusing error signal so as to generate a coupled signal. The focus compensator generates a focus control signal used for controlling a position of the pick up head of the optical disk drive according to the coupled signal during a focusing operation.

Abstract: A lever fixing apparatus of a cassette housing has at least one lever for connecting a cassette holder to a chassis and at least one snap fixing unit for connecting the lever to at least one of the cassette holder and the chassis in a snap manner to hingedly fix the lever thereto. The lever fixing apparatus can fix the lever to the chassis without using additional coupling parts. Accordingly, the number of processes for assembling the cassette holder to the housing bracket can be reduced and the working time is saved, thereby the productivity being increased.

Abstract: An optical pickup includes a first optical source producing a first optical beam having a wavelength ?1, a second optical source producing a second optical beam having a wavelength ?2 (?1<?2), and a single objective lens focusing any of the first and second optical beams to an optical recording medium, the first optical beam is incident to the objective lens as a parallel beam and the second optical beam is incident to the objective lens as a divergent optical, wherein an aperture is provided at a front side of the objective lens with offset from a principal point at the front side by a distance t given by an equation t=L?NA1·f/tan(a sin(NA2obj)), wherein f represents a focal distance of the objective lens, NA1 represents the numerical aperture at the side of the image surface when the first optical source is turned on, NA2obj represents the numerical aperture at the front side when the second optical source is turned on, and L represents the object distance at the time when the second optical source is

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: By bring a master carrier and a slave medium into close contact with uniform force when executing magnetic transfer by applying transfer magnetic field in the state that the master carrier and slave medium is in confronted close contact and received within a holder, inferiority of transfer such as omission of signals is prevented and quality of transfer signals is enhanced. The magnetic transfer apparatus executes magnetic transfer by applying transfer magnetic field by means of a magnetic field applying apparatus 5 after a master carrier 3, 4 bearing transfer information and a slave medium 2 to be transferred are brought into confronted close contact and received within a holder 10, wherein said holder 10 has a substantially circular shape and in particular, the circularity of holder is not less than 98%, wherein the flexural rigidity=Ed3/12 determined by Young's modulus E and thickness d of the holder is in the range of 0.

Abstract: A unipivot tone arm assembly wherein the tone arm is supported by a single point is balanced in such a way as to have neutral stability providing constant tracking force over the peaks and valleys of phonograph records. Lateral stability lacking in a neutral balanced unipivot tone arm is provided by magnetic coupling between magnets on the tone arm housing assembly and a freely rotating platform. Anti-skate is accomplished through a pulley mechanism between the rotating platform and the tone arm gantry, with the pulley on a counterweighted rotating pivot arm.

Abstract: In a recording disk apparatus, a pickup element and an electric element for at lease one of supplying an electric power to at least one of a recording disk driving motor and the pickup and processing a signal to be recorded into the recording disk and/or the signal read from the recording disk are prevented from overlapping each other as seen in a thickness direction of the recording disk to restrain a thermal conduction between the pickup element and the electric element so that a thermal conduction restraining area extending along an imaginary directional line crossing an imaginary straight line passing the pickup element and the electric element as seen in the thickness direction is formed between the pickup element and the electric element as seen in the thickness direction.

Abstract: A data recording device comprises a block division unit dividing a sequence of user data blocks into first blocks and second blocks, a plurality of multi-level data generating units generating multi-level data blocks from the first blocks and the second block, a group data storage unit storing first and second groups of code data corresponding to one user data block, a plurality of averaging units each calculating an average of DC levels based on the multi-level data of one of the blocks, a level comparison unit comparing each of the DC level averages with a predetermined value; a revision data generating unit generating a revision data using a result of the comparison, a data selection unit selecting one of the first and second groups of code data, and an output storage unit storing the first blocks, the second blocks generated using the selected code data, and the revision data.

Abstract: A servo circuit includes a servo channel and a processor. The servo channel recovers servo data from servo wedges that identify respective data sectors on a data-storage disk. The processor detects one of the servo wedges on spin up of the disk, i.e., while the disk is attaining or after the disk attains an operating speed. By detecting a servo wedge instead of a spin-up wedge to determine an initial head position on disk spin up, such a servo circuit allows one to increase the disk's storage capacity by reducing the number of, or altogether eliminating, spin-up servo wedges from the disk.

Abstract: An optical disc apparatus includes a control section. The control section performs a first search while the tracking control is in the off state. The first search is for searching for a plurality of sets of the focus positions of the light beam and the spherical aberration amounts such that an amplitude of the tracking error signal is greater than a predetermined value. The control section performs a second search while the tracking control is in the on state. The second search is for determining a set of the focus position of the light beam and the spherical aberration amount such that the reproduced signal quality index is substantially optimal, among the plurality of sets of the focus positions of the light beam and the spherical aberration amounts obtained in the first search.

Abstract: A disk apparatus has an equalizing unit which performs PR equalization for the read signal from the disk based on a plurality of tap coefficients, a decoding unit which performs a decoding process for the equalized read signal, a calculating unit which obtains an ideal signal of the decoded read signal, and compares the ideal signal with the decoded read signal, thereby calculating an error signal E, and a control unit which groups the tap coefficients into at least a first and second coefficient groups which are groups of tap coefficients at symmetrical locations each, and determines tap coefficients of the first coefficient group in a range of a first limit value K1 according to the calculated error signal, determines tap coefficients of the second coefficient group in a range of a second limit value and supplies the determined tap coefficients to the equalizing unit.

Abstract: A tilt adjusting apparatus including a digital signal processor, a first drive integrated circuit, and a tilt adjuster. When an optical recording medium is loaded into a deck, the digital signal processor outputs a focus control signal to control a focus of an optical recording medium, measures a tilt with respect to the optical recording medium, and outputs a tilt adjustment signal and a switch control signal so as to adjust the tilt. The first drive integrated circuit either synthesizes the tilt adjustment signal and the focus control signal or receives only the focus control signal according to the switch control signal and then outputs the synthesized signal or the focus control signal to the optical pickup. The tilt adjuster synthesizes the tilt adjustment signal output from the first drive integrated circuit and the focus control signal and then outputs the synthesized signal to the optical pickup.

Abstract: An optical drive writes information to an optical medium by obtaining a write strategy for the optical medium from a write strategy table embedded in the optical medium. A write module in the optical drive reads an optical drive identification code from the optical medium to select a write strategy associated with the optical drive. The write strategy of the embedded write strategy table that is identified for the optical drive is retrieved by the write module to write information to the optical medium with the optical drive using the identified write strategy. In one embodiment, a time stamp of the identified write strategy retrieved from the optical medium is compared with a time stamp of a write strategy already available to the optical drive to select the most recent write strategy for use by the optical drive. The write strategy table is embedded in the optical medium at manufacture of the optical medium, such as by stamping or burning the data into the optical material of the optical medium.

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: A data storage array is provided such as for a distributed storage system or a consumer electronics device wherein increased data storage capacity is provided at the cost of increased power consumption in relation to industry standard power consumption rates. The array has a plurality of data storage devices, each having an actuator operably disposed in a data storing and retrieving relationship with a data storage medium. The data storage medium is rotated at a speed of substantially greater than 10,000 revolutions per minute, and each of the data storage mediums has a data storage capacity of substantially greater than 100 gigabytes. The increased heat created by the relatively faster rotation speed is handled through improved airflow made possible by a multiple device array constructed in accordance with embodiments of the present invention.

Abstract: A method for reading address information from an optical disc with a wobbled track groove includes the steps of: obtaining a sine wave address signal, a first address signal representing a first groove region with sine wave wobbled portions and an inverted phase portion, and a second address signal representing a second groove region with steep inward or outward displacements; multiplying a first reference signal, being phase-locked to, and having the same frequency as, the sine wave address signal, and the first address signal together to obtain a first multiplied signal; multiplying a second reference signal, being phase-locked to, and having a frequency twice as high as, the sine wave address signal, and the second address signal together to obtain a second multiplied signal; integrating the first, multiplied signal and the second multiplied signal separately to obtain a first integral and a second integral, respectively; and adding the first and second integrals together.