Abstract: An electroencephalographic headset includes: a supporter that includes expanding and contracting wires each having expansion and contraction properties and is to be attached to a head of a user by expansion and contraction of each of the expanding and contracting wires; and a plurality of electrodes that are provided to the supporter in defined placement.

Abstract: A biological signal measurement apparatus includes a supporter and a vital sensor. The supporter is made of a shape-memory material. The vital sensor is configured to acquire a biological signal of a user. The vital sensor is attached to the supporter.

Abstract: A hologram reproducing apparatus includes a first reference light path leading laser light from a laser light source so that a hologram recording medium is irradiated with first reference light; a diffracted light path leading diffracted light, generated from the hologram recording medium by irradiation with the first reference light, to a light receiving element having a plurality of pixels; and a second reference light path leading second reference light, having the same polarization direction as that of the diffracted light, from the laser light source to the light receiving element. The second reference light path is provided with a phase modulating element so that the phase difference between the diffracted light and the second reference light in a light receiving surface of the light receiving element is adjusted within a predetermined range.

Abstract: An electroencephalographic headset includes: a supporter that includes expanding and contracting wires each having expansion and contraction properties and is to be attached to a head of a user by expansion and contraction of each of the expanding and contracting wires; and a plurality of electrodes that are provided to the supporter in defined placement.

Abstract: An information processor includes a brain wave sensor adapted to output a brain wave signal by measuring brain waves of a subject, an external sensor adapted to sense the surrounding environment of the subject, an environmental change determination section adapted to determine, based on a sensor signal output from the external sensor, whether a stimulus resulting from a change in the surrounding environment of the subject beyond a steady state has been applied to the subject, an event-related potential detection section adapted to detect an event-related potential for the stimulus in the brain wave signal if it is determined that the stimulus has been applied to the subject, and a calculation section adapted to calculate, based on a feature quantity obtained from the detected event-related potential, a value representing the focus level of the subject on a target.

Abstract: A hologram recording and reproducing device controls an optical beam output from an external cavity semiconductor laser to improve a diffraction efficiency. The hologram recording and reproducing device includes an external cavity laser, a photodiode, a laser drive circuit and a laser diode controller. The external cavity laser has a laser diode adapted to emit an optical beam that is used to generate data light and reference light with which a hologram recording medium is irradiated. The photodiode detects the amount of the optical beam output from the external cavity laser. The laser drive circuit supplies a current to the external cavity laser. The laser diode controller controls the laser drive circuit to ensure that a value obtained by integrating the detected intensity of the optical beam with respect to time over a predetermined period is equal to predetermined recording energy.

Abstract: A hologram recording and reconstruction apparatus records and reconstructs a hologram in a recording layer of a holographic recording medium using a signal light beam and a reference light beam. The apparatus includes an objective lens, a spatial light modulator on which a reference light beam pattern for generating a reference light beam is displayed, a temperature sensor for detecting the temperature of the holographic recording medium, and a control unit for controlling the spatial light modulator to reduce a reference light beam pattern so that the reference light beam passes through the more inner portion of the objective lens or enlarge the reference light beam pattern so that the reference light beam passes through the more outer portion of the objective lens in accordance with the temperature.

Abstract: A hologram recording/reproducing device includes an optical section which irradiates a holographic recording medium with an optical beam; and a control unit which controls the optical section. The optical section includes a laser light source which emits the optical beam, and a spatial modulator which modulates the optical beam. By controlling the spatial modulator, the control unit displays a tilt-standard reference light pixel and a tilt-standard signal light pixel, and records a tilt-standard hologram.

Abstract: A hologram recording and reproducing device controls an optical beam output from an external cavity semiconductor laser to improve a diffraction efficiency. The hologram recording and reproducing device includes an external cavity laser, a photodiode, a laser drive circuit and a laser diode controller. The external cavity laser has a laser diode adapted to emit an optical beam that is used to generate data light and reference light with which a hologram recording medium is irradiated. The photodiode detects the amount of the optical beam output from the external cavity laser. The laser drive circuit supplies a current to the external cavity laser. The laser diode controller controls the laser drive circuit to ensure that a value obtained by integrating the detected intensity of the optical beam with respect to time over a predetermined period is equal to predetermined recording energy.

Abstract: A hologram recording and reproducing device controls an optical beam output from an external cavity semiconductor laser to improve a diffraction efficiency. The hologram recording and reproducing device includes an external cavity laser, a photodiode, a laser drive circuit and a laser diode controller. The external cavity laser has a laser diode adapted to emit an optical beam that is used to generate data light and reference light with which a hologram recording medium is irradiated. The photodiode detects the amount of the optical beam output from the external cavity laser. The laser drive circuit supplies a current to the external cavity laser. The laser diode controller controls the laser drive circuit to ensure that a value obtained by integrating the detected intensity of the optical beam with respect to time over a predetermined period is equal to predetermined recording energy.

Abstract: An apparatus for producing a duplicate hologram recording medium includes: a positioning section configured to place the duplication master and the duplicate hologram recording medium at predetermined relative positions; an angle selective plate arranged between the duplication master and the duplicate hologram recording medium, the angle selective plate having an angle selective film whose transmittance changes in accordance with an incidence angle of a light beam; and a duplicating-reference-beam generating and radiating section generating a duplicating reference beam, and radiating the duplicating reference beam at such an incidence angle that the duplicating reference beam is transmitted through a predetermined region of a recording layer of the duplication master and is reflected by the angle selective film.

Abstract: A hologram recording/reconstructing apparatus includes a spatial modulator in which a reference beam region and a reconstruction beam region are formed, and a controller configured to control a range of the reference beam region and a range of the reconstruction beam region. According to a temperature of a hologram recording medium during recording, the controller sets the range of the reference beam region to a first predetermined range and thereby sets a range of an incident angle of a reference beam on the hologram recording medium to a first predetermined angle range. According to a temperature of the hologram recording medium during reconstruction of recorded data, the controller sets the range of the reconstruction beam region to a second predetermined range and thereby sets a range of an incident angle of a reconstruction beam on the hologram recording medium to a second predetermined angle range.

Abstract: An external cavity type semiconductor laser that has a larger output and a more excellent single mode characteristic than a conventional external cavity type semiconductor laser is provided. The external cavity type semiconductor laser has a laser diode 11, a window glass 16, a grating, and a lens. The external cavity type semiconductor laser has several modifications over the conventional one. A first modification is that the window glass 16 is inclined to a beam emission surface 19 of a laser diode 11 for a predetermined angle. A second modification is that arrangements of the laser diode 11 and so forth are adjusted so that a S wave reaches the grating. A third modification is that when an output power of the laser diode 11 is 45 mW or less, a kink is suppressed.

Abstract: A hologram recording and reproducing device controls an optical beam output from an external cavity semiconductor laser to improve a diffraction efficiency. The hologram recording and reproducing device includes an external cavity laser, a photodiode, a laser drive circuit and a laser diode controller. The external cavity laser has a laser diode adapted to emit an optical beam that is used to generate data light and reference light with which a hologram recording medium is irradiated. The photodiode detects the amount of the optical beam output from the external cavity laser. The laser drive circuit supplies a current to the external cavity laser. The laser diode controller controls the laser drive circuit to ensure that a value obtained by integrating the detected intensity of the optical beam with respect to time over a predetermined period is equal to predetermined recording energy.

Abstract: A hologram recording/reproducing device includes an optical section which irradiates a holographic recording medium with an optical beam; and a control unit which controls the optical section. The optical section includes a laser light source which emits the optical beam, and a spatial modulator which modulates the optical beam. By controlling the spatial modulator, the control unit displays a tilt-standard reference light pixel and a tilt-standard signal light pixel, and records a tilt-standard hologram.

Abstract: A drive apparatus includes a light irradiation section for applying light from a light source via an object lens on a hologram recording medium having a recording layer on which a hologram is formed and a track formation layer on which an address recording track composed of a pit string recording address information representing the hologram recording position on the recording layer and an auxiliary track composed of a continuous groove formed side by side with the address recording track are formed, a light spot displacement section for displacing a light spot formed by the light irradiation section in a radius direction of the hologram recording medium, and a control section for controlling the light spot displacement section following a light information signal upon the auxiliary track traverse of the light spot obtained in accordance with the light spot displacement to execute a jump operation between the address recording tracks.

Abstract: A recording apparatus includes a drive unit that rotationally drives a holographic recording medium including a recording layer and a track forming layer that includes guide tracks formed at constant intervals in a radial direction, where a signal beam and a reference beam are emitted to the recording layer so that a hologram is recorded in accordance with the signal beam, a signal beam generating unit, a reference beam generating unit, a recording unit that emits the signal beam and reference beam into the medium and records the hologram, a rotation control unit that controls the drive unit so that the medium is rotationally driven at a constant rotation speed, and a recording control unit that selects some of the guide tracks so that radial-direction recording intervals of the holograms are statistically decreased towards the outer periphery and controls the recording unit to record the holograms along the selected tracks.

Abstract: A laser system includes a laser diode that oscillates in a multi-mode and has characteristics in which its oscillation wavelength varies with temperature, a grating that receives a light beam emitted from the laser diode and returns a diffracted beam to the laser diode, a mechanism that changes the wavelength of the diffracted beam returned to the laser diode, a wavelength detector that detects the wavelength of an output beam which is the same as that of the diffracted beam returned to the laser diode, a temperature regulator that maintains the laser diode at a predetermined temperature, and a control unit that controls the mechanism so that the output beam having a predetermined wavelength is output and controls the temperature regulator so that the laser diode oscillates at the predetermined wavelength.

Abstract: A wavelength determining apparatus is disclosed. The wavelength determining apparatus includes a reflection block, a light detection block, and a determination block. The reflection block receives at least part of a laser light beam emitted from an external cavity type semiconductor laser and emits a reflected light beam that has a distribution of light intensities of fringes. The light detection block detects the intensity of the light beam reflected from the reflection block in two or more light reception positions. The determination block obtains a difference value of detection signals in the two or more light reception positions and determines the wavelength of the laser light beam on the basis of the difference value. The two or more light reception positions are arranged in the direction of which the fringes take place.

Abstract: A holographic recording and reconstructing apparatus includes a light source having a variable oscillation wavelength; a temperature sensing unit operable to sense temperature; and a control unit operable to record information about a temperature sensed by the temperature sensing unit on a holographic recording medium during recording, to obtain the information about the temperature from the holographic recording medium and obtain a temperature sensed by the temperature sensing unit during reconstruction, to determine the amount of wavelength shift to counteract the effects of a change in the dimension of the holographic recording medium between recording and reconstruction based on the difference between the temperatures, and to shift the oscillation wavelength of the light source by the determined amount.