Abstract: An optical head that is restrained from becoming larger, even if it is used for an optical-information recording medium that includes a plurality of information recording layers. In this optical head, a collimating lens is formed by a concave lens disposed on the side of a light source and a convex lens disposed on the side of an objective lens. A collimating-lens actuator moves the convex lens in a direction where a spherical aberration is cancelled which is generated according to the thickness of a light transmission layer up to an information recording layer of the optical-information recording medium. An aperture stop is provided on the side of the collimating lens with respect to the objective lens, and the aperture stop is located near the focal position of the convex lens on the side of the objective lens.

Abstract: An information recording medium having at least a read only area and a recording and reproducing area is composed of at least: a substrate; a recording layer formed on the substrate so as to record and reproduce information; and a light transmission layer having transparency formed on the recording layer. The information recording medium is further characterized in that a wobbling groove corresponding to the read only area and another wobbling groove corresponding to the recording and reproducing area is formed on the substrate without overlapping with each other, the recording and light transmitting layers are continuously adhered over at least two areas of the read only area and the recording and reproducing area, reflectivity of the recording layer is more than 5%, and a push-pull signal output T3 reproduced from the read only area and another push-pull signal output T4 reproduced from the recording and reproducing area before recording satisfies relations of T3?0.1, T4?0.1 and 1.5?T3/T4?0.5.

Abstract: An optical system (20) for efficiently collimating an elliptical light beam includes a light source (21), a first lens (22), a second lens (23), and a third lens (24). The light source is adapted for providing an elliptical light beam defining different diverging angles in different directions, wherein any cross-section of the elliptical light beam emitted from the light source defines a long axis and a short axis which are perpendicular to each other. The first lens, the second lens, and the third lens are used for reconfiguring the elliptical light beam, thus obtaining a round light beam having equivalent short axis and long axis, and equivalent diverging angles in both horizontal direction and vertical direction. Optical centers of the first lens, the second lens, and the third lens commonly define a common optical axis along which the elliptical light beams travels.

Abstract: A focus servo apparatus for an optical disc apparatus including an objective lens to converge laser beam on an information recording surface of an optical disc, and an actuator to move the objective lens in a focusing direction crossing the information recording surface, the focus servo apparatus comprising: a retaining unit configured to retain control data for driving the actuator; and a setting unit configured to set the control data retained by the retaining unit as initial data for driving the actuator, in the case of driving the actuator, to detect a position of the objective lens where the laser beam is focused on the information recording surface, as a target position when performing focus servo.

Abstract: A write-once-type recording medium (100) on which record data can be recorded only once, provided with: a data area (108) to record therein the record data; and a shared area (104, 105) to temporarily record therein evacuation data which is record data to be recorded or already recorded at a position of a defect in the data area and defect management information (120) including an evacuation source address of the evacuation data, the evacuation data being recorded with one predetermined point which exists in the shared area as a start point, the defect management information being recorded with another predetermined point which exists at a different point from the one point as a start point, in the shared area.

Abstract: A playback device for playback of a media stream stored on a storage medium, the device includes a controller for controlling the reading, buffering and playback of the media stream. During playback, a buffer is filled by a reader and emptied by a playback unit. At each buffer, filling a buffer refilling time, i.e., the moment when the buffer will be empty and thus has to be refilled, is calculated. After each buffer filling, the storage medium can change to standby mode till buffer refilling is to occur. Thus, power consumption by the storage medium is minimized. The buffer refilling time depends on the total consumption time and the buffer filling period. The total consumption time is determined depending on playback mode control information. The buffer filling period is calculated depending on information about the retrieval of the media stream or an estimation of the buffer filling period is made.

Abstract: An optical head includes a first laser diode configured to generate a laser beam with a wave length of ?1, a second laser diode configured to generate a laser beam with a shorter wave length of ?2 than the wave length ?1, a collimator lens arranged so that the laser beams are incident on it, an aperture filter arranged on an optical axis of the collimator lens, and an object lens 0 arranged on the optical axis so that the laser beams passing through the aperture filter are incident on it, wherein the second laser diode is arranged at a position on the optical axis further away from collimator lens than the first laser diode is away from the collimator lens.

Abstract: An armature for a receiver includes a first leg portion, a second leg portion, and a connection portion in communication with the first and second leg portions. The connection portion reduces the stiffness of the armature and minimizes magnetic reluctance of the connection between the first and second leg portions.

Abstract: A body device includes: a plurality of sound sources; a speaker and a headphone for outputting sound signals from those sound sources; and a mode setting unit capable of setting a single mode, in which the sound signals from one sound source are output in response to an operation from a front operation unit, and a dual mode in which, while the sound signals from one sound source are being output from the speaker, the voice signals from another sound source are output from the headphone; an external connection unit for connecting an external DVD device with the outside; and a control unit for controlling a mode setting unit so that the body device may be turned ON in the dual mode when a power ON demand signal from the external DVD device or a rear operation unit is detected.

Abstract: The object of the present invention is to curtail the time required from the receipt of a demand for certification processing of a rewritable optical disk from an apparatus of the higher order to the receipt of a demand for recording processing. In order to achieve this object, a digital data recording method for recording on a rewritable optical disk includes certification processing including a first step of recording certification data for the certification processing on the optical disk, a second step of recording user data different from the certification data on the optical disk after the first step, and a third step of reproducing the data recorded in the first step or the second step after the second step, and switches the certification processing based on the result reproduced in the third step.

Abstract: A method is disclosed to determine an optimal optical detector orientation to decode information encoded holographically. The method supplies a matched filter, an orientation image, a holographic data storage medium encoded with the orientation image, and an optical detector comprising a moveable input screen comprising a plurality of detector elements. The method positions the input screen in a plurality of input screen orientations and calculates a correlation factor for each of the input screen orientations. The method determines an optimal optical detector orientation using the plurality of correlation factors.

Abstract: A recording method, a host apparatus, a recording and/or reproducing apparatus, an optical recording information storage medium, and a computer readable recording medium storing a program for performing the method of recording. The method of recording data on a disk includes: when new data is desired to be recorded on the disk, at an address at which data is already recorded, updating a defect list by writing in the defect list defect information of the address at which the data is already recorded; and transmitting to a recording and/or reproducing apparatus the updated defect list and a command to record the new data at the address at which the data is already recorded. According to the method, overwriting is implemented on a write-once medium and furthermore, when this overwrite is implemented, the load on the drive system is reduced.

Abstract: An optical pickup which includes first to third light sources each emitting a light beam each having a first to third wavelength; an objective lens condensing each of the light beams emitted from the light sources on a signal recording face of an optical disc; a collimator lens provided between the light sources and the objective lens to convert a divergent angle of each of the light beams emitted from the light sources so as to obtain a parallel light beam; and a diffractive optical element provided between the collimator lens and the objective lens. The diffractive optical element includes first and second diffractive parts which respectively diffract the light beam having the second wavelength and the third wavelength. The second diffractive part has a diffraction structure formed by a plurality of concentric ring zones, having first to fourth optical faces, each having a different height in an optical axis direction.

Abstract: An information recording medium having at least a read only area and a recording and reproducing area is composed of at least: a substrate; a recording layer formed on the substrate so as to record and reproduce information; and a light transmission layer having transparency formed on the recording layer. The information recording medium is further characterized in that a wobbling groove corresponding to the read only area and another wobbling groove corresponding to the recording and reproducing area is formed on the substrate without overlapping with each other, the recording and light transmitting layers are continuously adhered over at least two areas of the read only area and the recording and reproducing area, reflectivity of the recording layer is more than 5%, and a push-pull signal output T3 reproduced from the read only area and another push-pull signal output T4 reproduced from the recording and reproducing area before recording satisfies relations of T3?0.1, T4?0.1 and 1.5?T3/T4?0.5.

Abstract: A source device (110) receives a carrier signal and continuously monitors the carrier signal for a first predetermined condition and a second predetermined condition. The source device (110) transmits data if the first predetermined condition is satisfied. The source device (110) ceases transmission of data if the first predetermined condition subsequently is not satisfied or if a second predetermined condition is satisfied.

Abstract: An apparatus for detecting a pre-pit signal at different laser power intensities of an optical disk drive. The apparatus includes an amplifier for receiving a push-pull signal acquired from an optical disk to generate an adjusted signal, a multiplexer for receiving the push-pull signal and the adjusted signal and selecting the push-pull signal or the adjusted signal as a slicing signal for output according to a power state signal, and a slicer for receiving the slicing signal and slicing the slicing signal according to a slicing level to generate the pre-pit signal. Thus, the apparatus only needs one set of slicer to correctly slice the pre-pit signal.

Abstract: A transducer (1) for producing sound in response to an electrical signal comprises an actuator (2) with a magnet (4) and a coil (5), and a vibration surface (3), for example a loudspeaker cone. The actuator and the vibration surface are mechanically coupled. The transducer (1) is designed to operate at substantially its resonance frequency (f0). This results in a very high transducer efficiency, which is particularly relevant for rendering low audio frequencies.

Abstract: A tracking error control system includes a tracking error signal generator in communication with an optical pickup head, a DC detector in communication with the tracking error signal generator and a comparator in communication with the DC detector and the tracking error signal generator. The operating optical signals received by the optical pickup head are operated with an offset signal to generate a tracking error signal. A direct current voltage of the tracking error signal is detected and compared with a reference voltage. The offset signal is adjusted according to the comparison result and fed back to the tracking error signal generator to adjust the tracking error signal.

Abstract: A low-power implant system. The system includes an implant for implantation into a person, such as a cochlear implant or a middle ear implant. The implant is capable of communicating with a device via transmission of ultra wideband pulses. The device may be adapted to be worn external to the person, or may be a second implant. So as to conserve battery power, the transmitted ultra wideband pulses may have a low duty cycle of approximately 1/1000 or less. Power savings may also be realized by using time-gating amplifiers in the implant and/or device receiver.

Abstract: An optical head that is restrained from becoming larger, even if it is used for an optical-information recording medium that includes a plurality of information recording layers. In this optical head, a collimating lens is formed by a concave lens disposed on the side of a light source and a convex lens disposed on the side of an objective lens. A collimating-lens actuator moves the convex lens in a direction where a spherical aberration is cancelled which is generated according to the thickness of a light transmission layer up to an information recording layer of the optical-information recording medium. An aperture stop is provided on the side of the collimating lens with respect to the objective lens, and the aperture stop is located near the focal position of the convex lens on the side of the objective lens.