Abstract: A method and apparatus of compensating for misalignment in an optical disk device includes detecting a plurality of focus error signals, comparing the focus error signals, and shifting a position of an optical lens based on the comparison. Alternatively, a one or more of the focus error signals may be compared to a reference signal and a corresponding shift may be performed. When the lens is shifted, an optical spot corresponding to an optical beam reflected from a disk surface is corrected to a position which reduces or eliminates misalignment errors attributable to one or more elements of the pickup.

Abstract: An information recording medium of the optical information reproduction device of the present invention includes a recording unit capable of recording information three-dimensionally and provided with a track, and information is recorded by forming a plurality of recording marks along the track of the recording unit by a mark length recording method. When the track direction of the recording marks is assumed to be their longitudinal direction and the direction perpendicular to the track direction is assumed to be their lateral direction, with the present invention, for recording marks located substantially in the same plane, the total area of elongated recording marks, whose longitudinal length is greater than their lateral length, is greater than the total area of recording marks having other than elongated shapes.

Abstract: According to one embodiment, in a disk drive, a voice coil motor is controlled to cause a head to minutely vibrate in a radial direction on a track of a disk. When the voice coil motor vibrates the head in the radial direction of the disk, frictional force occurring between the disk and the head is calculated based on the driving force of the voice coil motor generated to vibrate and detected positional information, thereby measuring frictional characteristics.

Abstract: Various embodiments of the present invention provide systems and methods for using channel bit density estimates to adjust fly-height. For example, various embodiments of the present invention provide methods for adaptively adjusting fly-height. Such methods include providing a storage medium that includes information corresponding to a process data set, and a read/write head assembly that is disposed a variable distance from the storage medium. The process data set is accessed from the storage medium. A first channel bit density estimate is adaptively calculated based at least in part on the process data set and a second channel bit density estimate that was previously calculated. The variable distance is modified based at least in part on the first channel bit density estimate. A third channel bit density is adaptively calculated based at least in part on the process data set and a fourth channel bit density estimate that was previously calculated.

Abstract: An optical pickup device to provide a stable operation in both low-speed and high-speed modes by controlling a change in natural frequency, the optical pickup device including: a lens holder to support an objective lens; a supporting unit spaced apart from the lens holder; and a plurality of suspension members each having one end fixed to the lens holder and another end supported by the supporting unit to enable a movement of the lens holder, wherein the supporting unit includes a fixing member, a coupling portion provided in the fixing member to couple each suspension member, magnetic fluid received in the coupling portion, and an excite device to apply a magnetic field to the magnetic fluid.

Abstract: A method, apparatus and program storage device for dynamically adjusting the write current in each head to compensate for variation in disk drive and environmental parameters is disclosed. A current in the write head is dynamically adjusted to compensate for variations in the components and environment by periodically measuring the writability of the drive and adjusting the write current such that the parameter stays within predetermined criteria.

Abstract: An information recording apparatus and method can prevent an information recording medium having a plurality of recording layers from being incompatible with a reproduction-only information recording medium due to an unrecorded area, which is produced by completion of recording in a middle of a data area of the recording layer. The recording layers include at least a first recording layer and a second recording layer, the first recording layer providing a reference with respect to a position of said data area in each of the recording layers. The user data is recorded in response to a recording request. After recording the user data, predetermined data is recorded in a predetermined unrecorded area in the second recording layer.

Abstract: The optical pickup device according to the present invention includes: a light source which emits a first light at a first wavelength, a second light at a second wavelength and a third light at a third wavelength; an optical path combining unit which combines vectors of the first, second and third light emitted by the light source, and matches optical axes of the first light and the third light; a light collection unit which condenses the light from the optical path combining unit into the optical information storage medium; a diffraction element which diffracts reflected light from the optical information storage medium; a first photo detector, a second photo detector and a third photo detector which receives the diffracted light from the first diffraction element; and a prevention unit formed between the first diffraction element and the first photo detector, the second photo detector and the third photo detector, and which prevents irradiation of + first-order diffracted light diffracted by the first diffr

Abstract: A method for manufacturing a hard-disk drive (HDD). The method for manufacturing a HDD includes writing servo tracks, and writing servo tracks into the HDD using a calculated control target value of a calculated servo pattern overlap amount. Writing servo tracks includes a first, second, third and fourth operation. The first operation includes: producing a first control equation for obtaining a servo pattern overlap amount; and, converting a root-mean-square error (RMSE) into a probability distribution. The second operation includes calculating a second control target value that results in an increased product yield, from the RMSE probability distribution. The third operation includes producing a second control equation for obtaining a calculated servo pattern overlap amount, by assigning the second control target value into the first control equation.

Abstract: An objective lens consists of a single lens element. A light source side surface is formed into a convex surface having a large curvature, and an optical recording medium side surface has a small curvature. The both surfaces are formed into aspheric surfaces. Also, the objective lens satisfies the following expressions (1) to (3): 0.70<NA<0.98??(1) 0.70<d/f<3.00??(2) 0.50<g/d<0.80??(3) where NA denotes a numerical aperture of the objective lens on an optical recording medium side, d denotes a thickness, in mm, of the objective lens on an optical axis, and g is a distance, in mm, from a tangential plane that is perpendicular to the optical axis and is tangent to a vertex of the light source side surface of the objective lens, to a center of gravity of the objective lens.

Abstract: A servo track writing method and a servo track write system of a hard disk drive (HDD) using the servo track write method. The servo track writing method includes performing a reference check (R/C) on a first servo pattern which is pre-written on a first surface of a disk, and if the R/C determines that a quality of the first servo pattern is not good, erasing a specific area of the first servo pattern and writing a second servo pattern on a second surface of the disk. Therefore, process time delay factors of a series of rework processes of writing servo patterns on a disk are removed to shorten a process time of the rework processes. In addition, productivity of a HDD is improved.

Abstract: A disk drive for determining a write jog value is disclosed. The disk drive comprises: a disk; a head including a reader and a writer; and a processor. The processor controls operations in the disk drive including: commanding the reader to track follow on a first track, wherein the writer is located over an uncalibrated track position; commanding the writer to write a first test pattern on a section of the disk; commanding the writer to move by a plurality of step amounts to write a plurality of test patterns; commanding the reader to move by a second plurality of step amounts to read the plurality of test patterns; determining a reader signal value associated with each test pattern; determining the uncalibrated track position based on the read signal values; and determining the write jog value based on the distance between the first track and the uncalibrated track position.

Abstract: A method reads text data from a musical disc in a disc drive. The musical disc includes a plurality of blocks each including a plurality of packs. Each pack is given a block number and a sequence number and written to a ring buffer of a disc drive including a first memory and a second memory.

Abstract: Payload 0 as a header is recorded to a head of a UDI area. In the case of recording payload 0 and other payloads, each of them is quintuple-recorded in order to take a countermeasure against errors. Other payloads such as payload 1 and the like are recorded after payload 0. In the case of quintuple-recording, the payloads of the same payload number are collectively quintuple-recorded. AUDI is recorded from a position after one second from start time S. The payloads are arranged in positions at 12-frame intervals. Thus, the five data which is multiple-written are not arranged in the radial direction of a disc but widely distributed onto tracks. Error resistance is improved. An interval of data is set to an optimum value in accordance with the number of multiple-writing times, a linear velocity, a recording position on the disc, and the like.

Abstract: An optical disc including: sectors each having a sector ID; a first area having a first set of sectors sequentially arranged on the disc according to their respective IDs; a second area having a second set of sectors sequentially arranged on the disc according to their respective IDs, the second area being located after the first area in respect of a disc scan direction, the second area including all information needed for playback of the entire disc and having at least one sector ID which duplicates that of a sector in the first set of sectors.

Abstract: An electron beam recording apparatus is disclosed that records information onto the surface of a sample by using an electron beam. The electron beam recording apparatus includes an electron source that irradiates the electron beam, a magnetic detector that is configured to move onto and out of an irradiation axis and acquires magnetic information on the irradiation axis, a convergence position control part that calculates a convergence position correction amount for correcting a convergence position of the electron beam with respect to the surface of the sample based on the magnetic information, and a convergence position adjusting part that adjusts the convergence position of the electron beam with respect to the surface of the sample. The convergence position control part causes the convergence position adjusting part to adjust the convergence position of the electron beam with respect to the surface of the sample based on the convergence position correction amount.

Abstract: An integrated circuit for optical disc comprising for each of light-receiving surfaces: an operational amplifier including inverting and noninverting input terminals receiving first and second input voltages, and output terminal receiving output voltage; a feedback resistor connected between the inverting input and output terminals; a photodiode connected between one power supply line of the first and second power supply lines and the inverting input terminal to generate current corresponding to reflected light; a capacitor connected between the one power supply line and the noninverting input terminal; and an input resistor connected between reference power source and the noninverting input terminal, further comprising: an adder adding voltages corresponding to the output voltages to generate RF signal, capacitance of the capacitor and resistance value of the input resistor being determined in accordance with capacitance of parasitic capacitor connected in parallel with the photodiode and resistance value of

Abstract: Upon scanning with an optical spot from a first address on the first recording layer as a start point for a second address on the second recording layer which is a target address for reproducing in order to detect a reproduction position, a scanning path for reaching the second address by scanning an already recorded zone of at least one of the first recording layer and the second recording layer is selected from a first scanning path to carry out seeking after a focus jump and a second scanning path to carry out seeking before the focus jump, based on a positional relationship between a known boundary position between a not-yet-recorded zone and an already-recorded zone of the first recording layer or the second recording layer and the first address.

Abstract: Methods, systems, and apparatus, including computer program products, are described for calibrating voice coil motors. In one aspect, a method is provided that includes seeking toward an outer diameter of a machine readable medium from a target servo track to a blank portion of the machine readable medium. A radial velocity of an actuator is determined after accelerating the actuator to a target radial velocity. The radial velocity is compared to the target radial velocity, and a current, that is used to controllably modify the radial velocity of the actuator if the radial velocity is different from the target radial velocity, is calibrated.

Abstract: It is highly precisely determined as to whether or not a laser-irradiated position on an optical disk is positioned within an identification area (BCA) in which identification information is recorded, and the position of the identification information area is efficiently determined. An optical disk apparatus includes an optical pickup for detecting reflected light from an optical disk and generating a light amount signal, and a detecting section for outputting a detection signal which is in accordance with a change in the signal level of the light amount signal, the detection signal indicating that the change has continued for a first predetermined time or longer.