Abstract: A data medium of the compact disc type may include medium areas of different types configured to define digital content, and a controllable element having two different states corresponding respectively to the two different types of areas. The controllable element may be configured to take selectively one of its states in response to a command, so as to modify in a controllable manner the content of the data medium.

Abstract: A laser holder holds a semiconductor laser that has a metal frame part in which a semiconductor laser chip is mounted on one surface, and a resin part provided so as to surround the semiconductor laser chip. The laser holder is provided with an insertion part into which the semiconductor laser is inserted. The insertion part is provided with an aperture part that allows the resin part of the semiconductor laser inserted into the insertion part to be pushed from the exterior, and a wall surface part against which a reverse surface of the one surface of the metal frame part is pressed in a case where the resin part is pushed from the exterior.

Abstract: A disk drive is disclosed comprising a first head actuated over a first disk surface, and a second head actuated over a second disk surface. A first fly height (FH) setting is adjusted for the first head, and a second FH setting is adjusted for the second head. When a ratio of the first FH setting to the second FH setting exceeds a threshold, corrective action is taken.

Abstract: The present invention relates to a recording/reproducing device that records data on a double-sided recordable optical disk for storage and management purposes. The device includes a unit which stores a plurality of optical disks, a unit which records data onto and reproduces data from an upper side of an optical disk, a unit which records data onto and reproduces data from a lower side of an optical disk, a unit which conveys an optical disk between the disk storage unit and each recording/reproducing unit. When a request for reading data recorded on the lower side of the disk is received while the upper side is being written onto, a control unit interrupts a data recording process on the upper side, reproduces data recorded on the lower side, and after completion of reproducing the recorded data, resumes the interrupted data recording process.

Abstract: In an optical recording method, recording parameters (WU) to be used for recording are obtained using recommended recording parameter values (WR) read from an optical recording medium and previously obtained vector information (PC) and approximation coefficients (Ca, Cb) (S24). Writing to the optical recording medium is performed using the obtained recording parameters (S17). The vector information (PC) includes a vector component of the parameters obtained statistically with respect to parameter difference values (DF) between optimal recording parameter values (WO) and the recommended recording parameter values (WR) over a plurality of optical recording media so as to strengthen mutual correlation between the parameters.

Abstract: A magnetic recording disk drive has a fly-height sensor on the slider that supports the read/write head. The head-disk spacing signal from the fly-height sensor utilizes the existing read path between the arm electronics (AE) module and the channel electronics module. A variable gain amplifier (VGA) on the AE module receives as one input the head-disk spacing signal and as the other input an emulated read signal. The output of the VGA is thus an oscillatory signal that emulates the read signal but whose amplitude varies as the head-disk spacing varies. A multiplexer (MUX) on the AE module multiplexes the amplified read signal from the read amplifier with the VGA oscillatory output signal on the read path back to the channel electronics module.

Abstract: An objective optical system for information recording/reproducing, at least one of optical surfaces of the objective optical system comprising a diffraction surface including a first region contributing to converging first, second and third beams and including a diffraction structure formed such that use diffraction orders for the first, second and third beams are 1st-orders and a condition 0.03<(?B11??1)/?1<0.40 is satisfied; a second region contributing to converging only the first and second beams and including a diffraction structure formed such that the use diffraction orders are 1st-orders and a condition: ?0.35<(?B12??B11)/?1<0.35 is satisfied; and a third region contributing to converging only the first beam and including a diffraction structure formed such that the use diffraction order for the first beam is an odd order and a condition: ?0.23<m13 ((?B13??1)/?1)<0.23 is satisfied.

Abstract: A shingled magnetic recording disk drive with sector error correction code (ECC) has the disk recording surface divided into multiple zones. Each zone is assigned a sector-ECC strength, i.e., a unique number of ECC sectors associated with a block of data sectors. The zone in which data is to be written is determined from the time average of the position-error signal (PES), which is an indication of the track misregistration (TMR) and thus the current environmental condition to which the HDD is subjected.

Abstract: A digital loop filter receives a phase error output from a phase comparator to generate a digital frequency value. This digital frequency value is converted into an analog voltage by a D/A converter, and VCO outputs a synchronizing dock of frequency corresponding to the voltage output from the D/A converter. The phase error output from a phase comparator is gain-corrected by a product of an output from the digital loop filter and a specific coefficient “A”, and delivered to digital loop filter. The phase error input to the digital loop filter is changed in proportion to the output clock frequency, whereby the PLL loop as whole linearly controls the loop characteristic depending on the output clock frequency.

Abstract: Systems and methods for controlling light phase difference in interferometric waveguides at near field transducers by selectively heating the light source are provided. One such system for controlling light phase at the NFT of an interferometric waveguide includes a laser, a heater configured to heat the laser, a splitter configured to receive light from the laser and to split the light into a first waveguide arm and a second waveguide arm, the first waveguide arm and the second waveguide arm converging at a junction about opposite the splitter, and the NFT proximate the junction and configured to receive the light, where the first waveguide arm is longer than the second waveguide arm by a preselected distance, and where the heater is configured to generate and maintain a preselected phase difference in the light arriving at the NFT via the first waveguide arm and the second waveguide arm.

Abstract: Systems and methods for increasing media absorption efficiency using interferometric waveguides in information storage devices are described. One such system for an interferometric waveguide assembly includes a light source, a first waveguide arm and a second waveguide arm, a splitter configured to receive light from the light source and to split the light into the first waveguide arm and the second waveguide arm, and a near field transducer (NFT) configured to receive the light from the first waveguide arm and the second waveguide arm, where the first waveguide arm and the second waveguide arm converge to form a preselected angle at a junction about opposite the splitter, and where the first waveguide arm and the second waveguide arm are configured to induce a preselected phase difference in the light arriving at the NFT.

Abstract: A recording/reproducing apparatus, for producing a virtual disc independent upon a host PC, and for managing virtual discs with an easy operation, comprises a CPU 100, a memory 101, a storage I/F 102, an external I/F 103, a device portion (DP) controller portion 201, a virtual device portion (VDP) controller portion 202, a virtual serial ATA 601, a virtual ATAIP 602, and at least two (2) or more numbers of recording/reproducing apparatuses, wherein it is notices to a HOST PC that a device is connected to the device portion when a virtual disc is produced, and the virtual disc is cut off and also information corresponding thereto is deleted when taking out or an order of taking out is made from the HOST PC.

Abstract: A disk drive is disclosed comprising a head actuated over a disk, a spindle motor operable to rotate the disk, and control circuitry comprising a speed control loop operable to control a rotation speed of the disk. A rotation speed of the disk is measured, and a speed error is generated in response to the measured rotation speed. The speed error is processed with a compensator to generate a control signal, a disturbance is injected into the control signal to generate a modified control signal, and the modified control signal is applied to the spindle motor. An amplitude of the disturbance is ramped, and after ramping the amplitude of the disturbance, an open-loop gain of the speed control loop is estimated at a frequency of the disturbance, and at least one parameter of the compensator is adjusted in response to the estimated open-loop gain.

Abstract: An optical information processing method and apparatus performs a light irradiating and receiving step, a signal processing step, and an adjusting step of a spherical aberration and a focus offset on the basis of shift amount of first and second control devices and a performance evaluation value. The performance evaluation values for first, second, third and fourth points in an x and y coordinate system are detected, in which an x-coordinate is one of the shift amount of the first control device and the shift amount of the second control device and a y-coordinate is the other, the first point, second and third points having the same y-coordinate and different x-coordinates with each other, the fourth point being provided on a first straight line passing through the first point and being different from the first point.

Abstract: To provide an optical disk device, an optical disk control method and an integrated circuit, which are capable of writing a recordable mark by changing the reflectance ratio of a reflective film formed on concave-convex pits without using an industrial special device or a high-power laser light source. A data reproduction controller (103) sets a first rotation speed in a disk rotation speed switching unit (108) and a first laser power in a laser power switching unit (107) when reproducing the concave-convex pits. When writing the recordable mark, a mark recording controller (104) sets in the disk rotation speed switching unit (108) a second rotation speed that is slower than the first rotation speed and the lowest rotation speed at which the concave-convex pits can be reproduced, and sets a second laser power greater than the first laser power in the laser power switching unit (107) in accordance with the emission timing.

Abstract: A disk drive is disclosed comprising a disk including a plurality of sectors each comprising a sector sync mark pattern and sector data preceding and following the sector sync mark pattern, and a head actuated over the disk for generating a read signal. A data sequence is detected from the read signal, and the data sequence is correlated with an extended sync mark comprising a target sync mark pattern and target data. The correlation of the target sync mark pattern with the data sequence is biased relative to the correlation of the target data with the data sequence.

Abstract: Disclosed are a pickup device assembly and an optical drive system. The assembly may comprise: a laser generator for generating laser beams; an objective lens; and at least one piezoelectric actuator for generating bending moments once applied with voltages, wherein the generated bending moments move the objective lens such that the laser beams are focused by the objective lens and then aim at concentric spiral data tracks of a disc with a strongest reflected signal of the laser beams from the disc.

Abstract: A reproducing device includes: a laser light irradiating section; a correction coefficient information retaining section; a correction coefficient obtaining section; a laser power setting section; and a driving signal outputting section.

Abstract: Provided is an information storage medium that has a plurality of recording layers, a recording/reproducing method, and a recording/reproducing apparatus. In the information storage medium, each of the plurality of recording layers includes an inner circumference zone and a data zone, and at least one of the recording layers includes, in the inner circumference zone, a temporary disc management area (TDMA) for recording information about a defect detected in the data zone, wherein a size of a TDMA allocated on an upper layer is greater than a size of a TDMA allocated on a lower layer.

Abstract: Provided is an objective lens including a diffraction portion provided on a laser beam incident plane or output plane. The diffraction portion includes first second, and third diffraction regions, wherein first laser beams corresponding to a first optical disc having a first transmissive layer are condensed on a data recording portion of the first optical disc, second laser beams corresponding to a second optical disc having a second transmissive layer thicker than the first transmissive layer are condensed on a data recording portion of the second optical disc, and third laser beams corresponding to a third optical disc having a third transmissive layer thicker than the second transmissive layer are condensed on a data recording portion of the third optical disc. An evaluation parameter calculated on the basis of an in-plane efficiency distribution function has a value corresponding to a symbol error rate that is less than a predetermined value.