Abstract: A semiconductor laser driving device is mounted on an information recording/reproducing device or the like, and is suitably used for recording and reproducing information. The semiconductor laser driving device is provided with a semiconductor laser for emitting laser beams, and a temperature detecting means for detecting a temperature of the semiconductor laser, and changes an output of the laser beams based on the detected temperature. Thus, the semiconductor laser driving means can suitably improve response characteristics of the semiconductor laser, irrespective of the temperature of the semiconductor laser. Therefore, the semiconductor laser driving device can ensure recording performance to an optical disc without being affected by the temperature of the semiconductor laser.

Abstract: In a two-dimensional probe array, an interval between the leading ends of probes adjacent to each other in an X direction is made shorter than that between the leading ends of probes adjacent to each other in a Y direction. Thus, the leading ends of the probes are arranged to form a lattice wherein many rectangles are arranged. Furthermore, the lowest resonance frequency of an actuator which moves a recording medium in the X direction is set higher than the lowest resonance frequency of an actuator which moves the recording medium in the Y direction. At the time of recording or reading information, the recording medium is reciprocated in the X direction at a frequency substantially equal to the lowest resonance frequency of the actuator.

Abstract: An optical pickup is provided for preventing an objective lens from colliding with an optical recording medium at the stage of initial adjustments. The optical pickup device comprises a servo circuit, and a lens driver for driving an objective lens. In the servo circuit, a drive signal generator supplies the lens driver with one of a first focus drive signal for moving the objective lens in a direction closer to an information recording layer, and a second focus drive signal for moving the objective lens in a direction away from the information recording layer. A controller in a timing generator switches a signal supplied to the lens driver from the first focus drive signal to the second focus drive signal when the level changes by a predetermined range or more in a servo signal which is generated during a period in which the first focus drive signal is being supplied to the lens driver.

Abstract: A probe group is composed of, for instance, four probes adjacently arranged, and one modulation circuit is arranged for each probe group. At the time of recoding information, a changeover switch connects one of the four probes with the modulation circuit, and subsequently changes the probes to be connected with the modulation circuit while reciprocal movement of a recording medium is being controlled.

Abstract: A focal follow-up control circuit performs follow-up control for a focal point on the data recording/reproducing region by reciprocating an object lens provided in a pickup with respect to a rotating direction of a data recording/reproducing region of an optical disk. The focal follow-up control circuit outputs a focal follow-up deviation signal indicative of a deviation between a follow-up central position of the object lens and a movable neutral point to a spindle control circuit. The spindle control circuit carries out feedback control of a number of rotations of a spindle motor so as to bring this focal follow-up deviation signal to zero.

Abstract: An optical pickup apparatus comprises a semiconductor laser output controller for emitting laser beam, a photodetector for detecting the emitted laser beam, a sampling processor for performing a sampling process, a pulse current generator for generating erase current pulses, write current pulses, and read current pulses, and a controller for controlling the above components. The apparatus performs the sampling process and generates the current pulses according to a predetermined APC timing and controls the semiconductor laser output controller based on the sampling process and current pulses.

Abstract: A drive apparatus including: a superposition device which superposes a superposition signal on a drive signal for driving a light beam emission device that emits a light beam and which outputs the drive signal on which the superposition signal is superposed to the light beam emission device, a reference clock signal generation device which generates a reference clock signal, a frequency change device which changes a frequency of the superposition signal based on a quality index for indicating a quality of a reproduction signal that is obtained from a reflection light that is the light beam reflected on a record medium, a phase locked loop device which controls the changed frequency so as to be constant by a feedback method in use of the generated reference clock signal.

Abstract: An example hologram recording and reproducing apparatus includes a recording unit which records information on a holographic recording medium by recording interference fringes formed by irradiation of a reference light and an object light corresponding to recording information, a reproducing unit which generates detected information data and a focus error signal on the basis of detected light from the holographic recording medium, and a focus servo unit that carries out focus servo on the basis of the focus error signal. The focus servo unit has a servo target value setting unit which sets a target value for focus servo on the basis of the detected information data. The detected information data also includes information indicative of the position relationship between the recording medium and the reference light or the like.

Abstract: A capacitance detecting apparatus which can detect the change in minute capacitance of a measuring object with high sensitivity comprises a signal generator, a differential amplifying circuit, and a detecting unit. The signal generator generates a probe signal w(t) to be applied to one end of the measuring object. The differential amplifying circuit amplifies differentially a response signal v1(t) developed at the other end of the measuring object in response to the application of the probe signal w(t) and the probe signal w(t). The detecting unit detects capacitance change of the measuring object based on the amplified signal v(t) from the differential amplifying circuit.

Abstract: A hologram reproduction apparatus includes a light-receiving unit such as a two-dimensional sensor which obtains two-dimensionally modulated image data, and an A/D converter which A/D-converts analog data obtained by the light-receiving unit into digital data. In addition, the hologram reproduction apparatus detects a number of pixels having a digital value larger than a first defined value in the A/D-converted image data for one page, by a first pixel number detecting unit. The hologram reproduction apparatus controls a magnitude value of the image data at the time of the A/D conversion by the first control unit so that the number of detected pixels is within a predetermined range. Thereby, a dynamic range of the A/D conversion to the two-dimensional modulated image data can effectively be used. Therefore, a quantization noise due to the A/D conversion can be reduced, and also a reproduction S/N can be improved.

Abstract: To provide a two-dimensional modulation method for hologram recording which is capable of preventing degradation of reconstructing performance when positional shift occurs and which enables information to be stably recorded or reproduced. The hologram recording carrier employs the two-dimensional modulation method for hologram recording for generating coherent light containing therein page data through a spatial light modulator having a plurality of pixels two-dimensionally arranged therein, in which the pixels of the spatial light modulator are partitioned into a plurality of blocks consisting of m pixels adjacent to each other (where m=an integral number), and a boundary portion which has a width having at least the width of one pixel of the spatial light modulator or of one pixel of an image detecting sensor used to reproduce the recorded page data and the distance between the adjacent pixels in each of the blocks, and each of which shields light is provided between the adjacent blocks.

Abstract: A template matching processing device includes: first calculation means for calculating a plurality of correlation values indicating the correlation between an inputted detection image and a predetermined template image for each pixel unit while shifting the template image with respect to the detection image in pixel unit; and second calculation means for calculation coordinate position of the detection image according to the coordinate position of the center of gravity of the correlation values.

Abstract: A recording medium (100) on which record information is recorded, wherein the recording medium is displaced relatively with respect to a recording/reproducing device (60) for performing at least one of recording and reproduction of the record information, along each of one direction (X-axis) and another direction (Y-axis), and a track (120) which is a guide in recording the record information is formed such that a relative displacement direction of the recording/reproducing device due to the at least one of recording and reproduction of the record information is distributed substantially uniformly in both the one direction and the another direction.

Abstract: A controller includes a servo-controller for performing nonlinear and linear control of the read/write position according to an error signal to drive an actuator for driving the pickup; a switch for switching the servo-controller from open-mode to closed-mode according to the error signal; and an adjuster for adjusting the gains of the nonlinear and linear control so that the nonlinear control component is larger than the linear control component at the time of switching and the linear control component is larger than the nonlinear control component after the elapse of a predetermined time from the time of switching.

Abstract: A hologram recording/reproduction device reproduces recording information from a holographic recording medium where interference fringes formed by a reference light and an object light corresponding to the recording information are recorded. The hologram recording/reproduction device includes: irradiation means for irradiating the reference light to a holographic recording medium; data generation means for generating detection information data (Ddet) according to the detection light generated by irradiation of the reference light; setting means for setting a target irradiation position of the reference light on the surface of the holographic recording medium according to the detection information data; and movement means for moving the irradiation means with respect to the holographic recording medium along its surface so that the reference light is irradiated to the target irradiation position.

Abstract: A controller includes a servo-controller for performing nonlinear and linear control of the read/write position according to an error signal to drive an actuator for driving the pickup; a switch for switching the servo-controller from open-mode to closed-mode according to the error signal; and an adjuster for adjusting the gains of the nonlinear and linear control so that the nonlinear control component is larger than the linear control component at the time of switching and the linear control component is larger than the nonlinear control component after the elapse of a predetermined time from the time of switching.

Abstract: In a tracking controller for an optical pickup, a photodetector having four light reception parts receives return light from an optical disc and outputs light detection electric signals. Predetermined addition and subtraction operations are performed on the light detection electric signals from the light reception parts. A phase comparator compares phases and outputs a pseudo radial contrast signal. Bringing into tracking servo control is performed based on the pseudo radial contrast signal.

Abstract: In an optical recording medium having a plurality of recording layers of a double-spiral structure in which information is recorded on both of land tracks and groove tracks, the spiral of a first recording layer (1) is in the forward direction, the spiral of a second recording layer (2) is in the backward direction, first information is recorded on one of the land track (1B) and the groove track (1A) of the first recording layer (1) in the direction from the inner periphery toward the outer periphery of the optical recording medium, and second information subsequent to the first information is recorded on one of the land track (2B) and the groove track (2A) of the second recording layer (2) in the direction from the outer periphery toward the inner periphery of the optical recording medium.

Abstract: An information recording apparatus is provided, which can control over the power of light beams emitted from a light source and various types of servo control with higher accuracy. A laser beam is emitted from a semiconductor laser to write information onto an optical disc. A detection signal indicative of the power of the laser beam output from a light-receiving device is sampled and held with a sample and hold circuit via an I-V converter at a timing delayed by the time corresponding to the delay time of the I-V converter. A tracking error generation circuit and a focus error generation circuit generate a tracking error signal and a focus error signal, respectively, on the basis of a detection signal having information about tracking error and focus error and output from a light-receiving device. Sample and hold circuits sample and hold the tracking error signal and the focus error signal at a timing delayed by the time corresponding to the delay time of each of the generation circuits, respectively.

Abstract: An optical pickup apparatus comprises a semiconductor laser output controller for emitting laser beam, a photodetector for detecting the emitted laser beam, a sampling processor for performing a sampling process, an averaging processor for performing an averaging process, a pulse current generator for generating erase current pulses, write current pulses, and read current pulses, and a controller 200 for controlling the above components. The apparatus adds averaged values and sampled values and controls the semiconductor laser output controller based on the result of the addition and on the current pulses.