Abstract: A method for irradiating a medium with a wave which is designed to focus on a particular portion in the medium, the method includes: irradiating the medium with an electromagnetic wave which is scattered in the medium, and is not designed to focus on the particular portion in the medium; detecting a first signal caused by irradiating the medium with the electromagnetic waver; irradiating the medium with a reconstructed wave which is designed to focus on the particular portion in the medium; detecting a second signal caused by irradiating the medium with the reconstructed wave; and monitoring, based on the first and second signals, that the particular portion is irradiated by the reconstructed wave.

Abstract: A lens driving device includes a lens holder for holding a lens, a supporter portion for supporting the lens holder in a movable manner, a drive portion for driving the lens holder, and an elastic portion for supplying the lens holder with a force in a predetermined direction. The supporter portion includes a shaft engaging with a bearing of the lens holder, and the force in a predetermined direction includes a force in a direction perpendicular to the shaft and a force in a direction to rotate the lens holder about the shaft.

Abstract: A method fabricates an interferometric tapered waveguide (ITWG) for a heat-assisted magnetic recording (HAMR) transducer. The ITWG is defined from at least one waveguide layer. The waveguide layer(s) include an energy sensitive core layer. The energy sensitive core layer has an index of refraction that varies in response to exposure to energy having a particular wavelength range. The step of defining the ITWG includes defining a plurality of arms for the ITWG. At least one phase difference between the arms is determined. At least one of the arms is exposed to the energy such that the index of refraction of the energy sensitive core layer in the arm(s) is changed and such that the phase difference(s) between the arms is changed.

Abstract: A microwave assisted magnetic recording head includes a recording magnetic pole unit that produces a recording field for writing to a perpendicular magnetic recording medium, and a high-frequency magnetic field oscillator that produces a high-frequency magnetic field. The recording magnetic pole unit includes a magnetic core with a write gap portion at which a main recording field component is concentrated, and the high-frequency magnetic field oscillator is disposed in the write gap.

Abstract: According to various embodiments, a method for reading data from a storage medium using a reader, wherein the reader includes at least one reader head, may be provided, wherein the storage medium includes a plurality of tracks. The method may include: reading a first signal with a reader head of the reader at a pre-determined position of the storage medium; reading a second signal with a reader head of the reader at the pre-determined position of the storage medium; and determining data stored at the pre-determined position of the storage medium based on the first signal and based on the second signal.

Abstract: A light-emitting diode bulb with loudspeaker function includes a bulb head, a drive power assembly, a heat radiator, a light-emitting diode module, a loudspeaker assembly, and a cover covered on the heat radiator. The drive power assembly is assembled to an upper portion of the bulb head, and is electrically connected with the bulb head. The drive power assembly includes a power supply circuit board assembly and a wireless module. The heat radiator is mounted to the upper portion of the bulb head. The drive power assembly is received in the heat radiator. The light-emitting diode module is mounted on the heat radiator, and is electrically connected with the power supply circuit board assembly. The loudspeaker assembly mounted on the light-emitting diode module, the heat radiator and the drive power assembly includes a fastening holder, an audio circuit board, a fastening bracket and a speaker unit.

Abstract: An optical pickup device is one in which a lens holder is held by a movable base by using a resilient wire. A restricting abutting portion is formed at a lower portion of the lens holder. When the lens holder moves excessively downward, the restricting abutting portion comes into contact with a stopper portion to restrict a downward movement of the lens holder, so that it is possible to prevent the lens holder from contacting a unit chassis. When the unit chassis is not mounted on the movable base, it is possible to prevent excessive flexing of the resilient wire caused when an opposing abutting portion of the lens holder comes into contact with the unit chassis.

Abstract: A testing device tests a magnetic head with a read head structure including a read head element while applying an external magnetic field to the magnetic head. The testing device receives signals from the read head element and processes the signals to generate a spectral power density for the signals. The spectral power density is characterized for at least one frequency range. The characterization of the spectral power density is used to determine a characteristic of noise from the read head structure. The signals from the read head may be received with different applied magnetic fields and/or before or while thermally exciting the magnetic head. Additionally, a histogram of the signals may be generated and used to determine a second characteristic of the noise.

Abstract: Devices, methods, and other embodiments associated with adjusting a defect threshold are described. In one embodiment, a method includes determining, using a defect threshold, when a read channel has read data from a defective portion of a storage medium. The defect threshold is adjusted based, at least in part, on a gain value and a delayed gain value of a gain loop of the read channel.

Abstract: A plasmon generator includes a first portion and a second portion that are adjacent in a first direction orthogonal to the direction of travel of light propagating through a core. The second portion includes a front end face located in a medium facing surface of a magnetic head. The core has a concave portion recessed from the top surface of the core. At least part of the first portion is received in the concave portion. The concave portion has a surface including an evanescent light generating portion. The first portion includes a plasmon exciting portion opposed to the evanescent light generating portion. The evanescent light generating portion is inclined relative to a first surface.

Abstract: An apparatus includes a transducer including a plasmonic funnel having first and second ends with the first end having a smaller cross-sectional area than the second end, and a first section positioned adjacent to the first end of the plasmonic funnel, and a first waveguide having a core, positioned to cause light in the core to excite surface plasmons on the transducer.

Abstract: Disclosed is an optical disk barcode forming method wherein, as information to be barcoded, position information for piracy prevention, which is a form of ID, is coded as a barcode and is recorded by laser trimming on a reflective film in a PCA area of an optical disk. When playing back the thus manufactured optical disk on a reproduction apparatus, the barcode data can be played back using the same optical pickup.

Abstract: A method of recording marks onto an optical disc, the optical disc comprising an information layer, by irradiating the information layer by a pulsed radiation beam, a mark (I3 . . . I14) having a time length of nT, n representing an integer larger than one and T representing the length of one period of a reference clock, being recorded by a sequence comprising m write pulses separated by cooling periods, the write pulses within the sequence being allowed to have different time lengths, the write pulses comprised in sequences corresponding to marks of different time lengths being allowed to have different lengths, m being an integer number given by Floor(n/?), where Floor(n/?) defines the largest integer smaller than n/?, wherein a is an integer number larger than or equal to 2. The method characterized by modifying at least the sequence comprising the longest write pulse such that the longest write pulse is replaced by two write pulses.

Abstract: A method to store information in a holographic data storage medium, wherein the method supplies a holographic data storage medium comprising an encoded focusing hologram and one or more encoded data holograms. The method disposes the holographic data storage medium in a holographic data storage system, and disposes a rotatable imaging lens at an (i)th orientation. The method illuminates the encoded focusing hologram to generate an (i)th reconstructed focusing image, projects that (i)th reconstructed focusing image through the rotatable imaging lens, and onto at optical detector array. The method then calculates an (i)th measured focusing metric, and determines if the (i)th measured focusing metric is greater than or equal to the threshold focusing metric. If the (i)th measured focusing metric is greater than or equal to the threshold focusing metric, then the method decodes the one or more encoded data holograms.

Abstract: An optical pickup device has a semiconductor laser emitting light which is in turn branched via a diffraction grating into at least three beams of light including a main beam and two sub beams which are in turn condensed via an objective lens on an optical disk at a guide groove and reflected by the optical disk to provide three reflections of light which are in turn received by detectors, each divided into two regions, respectively, to generate a tracking error signal. The diffraction grating is divided into three regions including a first region, a second region and a third region located intermediate therebetween, each having a periodical structure out of phase, the periodical structure having grating grooves in a direction determined depending on the phase of the second region to incline relative to a direction perpendicular to the guide groove of the optical disk.

Abstract: A method of defect management for managing on a block-by-block basis a defective area in an information-recording medium is disclosed. The medium has a user-data area, a sparing area, and a defect-management information are. The block is of a predetermined size. The method includes the steps of, when a defective block in which the defective area is included is set to be replaced with a sparing block of the sparing area: dividing the sparing block into multiple subblocks so as to set identifying information, for identifying a sparing subblock in which data are replaced and a non-sparing subblock in which data are not replaced, as defect-management information; and setting block-management information, including information regarding the defective block and the sparing block, and information regarding an area in which non-sparing data not replaced with the sparing block are stored, as defect-management information.

Abstract: A digital data demodulator which can reduce a loss of decodable digital data, and increase capability of reproducing digital data inputted through a transmission line even when an error occurs in the transmission line. In the digital data demodulator, a specific pattern detector (113) detects a specific pattern to be included in a modulation code, from a bit string inputted through a transmission line (104). A modulation code identifying unit (117) generates a demodulation data strobe signal (119) according to a phase of the modulation code including the specific pattern. An error corrector (121) samples demodulation data (109) in response to the demodulation data strobe signal (119) and reproduces the data to the original digital data.

Abstract: An optical disk apparatus is provided which can: prevent an SNR deterioration attributable to an increase in read speed; overcome difficulty in separating a read signal and HF signal components; reduce laser noise; and maintain high reliability even during a high-speed read operation. An optical disk is irradiated with laser light pulsed by a high-frequency signal generated by a HF oscillator. The output of an optical detector which receives laser light reflected from the optical disk is converted into an electric pulse read signal using a current amplifier. The pulse read signal is converted into a temporally continuous read signal using a combination of an AD converter and a DA converter.

Abstract: An optical disk apparatus includes an I/O port that connects to a port of a drive apparatus, and a storage unit that prestores manufacturing information in correspondence with device drivers. The optical disk apparatus further includes a controller that transmits a command indicating to return manufacturing information, to the drive apparatus via the I/O port. When manufacturing information is returned from the drive apparatus via the I/O port, the controller extracts a device driver corresponding to the returned manufacturing information from the device drivers in the storage unit. The controller then controls a reading operation or a recording operation of the drive apparatus on the optical disk, based on the extracted device driver.

Abstract: To provide a new recording method and recording apparatus with respect to an optical recording medium, the recording method and recording apparatus being able to deal with a high density of an optical recording medium of recent years. Recording of a recording track and a prepit is carried out by sequentially deflecting a single beam.