Sony Corporation

Tomiji Tanaka

Mikio Sugiki

Kazuo Takahashi

Hitoshi Okada

Koji Ishioka

Kageyasu Sako

Katsuhisa Aratani

Kenjiro Watanabe

Masato Hattori

Sohmei Endoh

Shinji Yamada

Takahiro Takeda

Noboru Sato

Mitsuru Toishi

Ryo Kasegawa

Tamotsu Ishii

Shigeo Kobayashi

Toshiyuki Nakagawa

Seiji Wada

Atsushi Fukumoto

Hiroshi Nakayama

Mitsuhiro Nakamura

Masayoshi Kanno

Masataka Shinoda

Koji Kashima

Yoshihiro Wakita

Masaaki Hara

Minoru Tobita

Tatsumi Sakaguchi

Yuji Suzuki

Shinichi Nakao

Motonobu Takeya

Satoru Seko

Shigeru Yamazaki

Ariyoshi Nakaoki

Natsuki Kimura

Katsuhiko Ohtomo

Takuro Yamamoto

Haruhiko Soma

Kazutatsu Tokuyama

Yoshiyuki Teraoka

Manabu Iwai

Katsuhiro Agatsuma

Hiroyuki Yamagata

Masaki Chiba

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.

Electroencephalographic headset

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.

Hologram reproducing apparatus, hologram reproducing method, and phase modulating element

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.

Hologram recording and reproducing device and method for recording hologram

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.

Hologram recording and reconstruction apparatus

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.

Hologram recording/reproducing device, method thereof, and holographic recording medium

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.

Method for producing a duplicate hologram recording medium, apparatus for producing a duplication master, apparatus for producing a duplicate hologram recording medium, and duplication master

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.

Hologram recording/reconstructing apparatus

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, a window glass, 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 glassis inclined to a beam emission surfaceof a laser diodefor a predetermined angle. A second modification is that arrangements of the laser diodeand so forth are adjusted so that a S wave reaches the grating. A third modification is that when an output power of the laser diodeis 45 mW or less, a kink is suppressed. The other modifications are that a reflectance of a beam emission surface of the laser diode, a numerical aperture of the lens, an external cavity length, and a reflectance of a first order beam of the grating are optimized to their proper values.

External cavity type semiconductor laser

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.

Laser system

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.

Wavelength determining apparatus, wavelength determining method, semiconductor laser controlling apparatus, and semiconductor laser controlling method

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.

Holographic recording and reconstructing apparatus and method

A laser apparatus is disclosed. An optical element receives at least a part of laser light emitted from a laser generation source and generates interference fringes. Each of first and second two-divided detectors has two detectors arranged in the direction of which the interference fringes appear. Each of the detectors detects an amount of light of the interference fringes. These two-divided detectors are spaced apart for an odd-number multiple of nearly &#xbc; period of interference fringes and disposed on a plane perpendicular to an optical path of the interference fringes. Each of first and second calculation sections calculates a first difference signal of detection signals of two detectors of the two-divided detector. A selection section selects one of the first and second difference signals. A determination section determines a wavelength of the laser light corresponding to a value of the difference signal selected from the first and second difference signals.

Laser apparatus

A laser apparatus is disclosed. The laser apparatus has a diffraction grating that receives laser light from a semiconductor laser, emits first order diffracted light having a predetermined wavelength to the semiconductor laser, and reflects zero-th order light, a reflection section that reflects the zero-th order light reflected by the diffraction grating, a hold section that holds the diffraction grating and the reflection section while an open angle of the diffraction grating and the reflection section is kept constant, the hold section being rotatable with a fulcrum of an intersection of an extended line of a front surface of the diffraction grating and an extended line of a front surface of the reflection section, and a linear drive section that rotates the hold section with a linear motion of a piezoelectric device that expands and shrinks by the piezoelectric effect.

Laser apparatus and method of driving diffraction grating

In the hologram recording and hologram-record reproduction using a one-dimensional optical modulator, the one-dimensional optical modulator where a plurality of light-modulating pixels are arranged modulates a laser beam to record a digital-data signal on a hologram recording medium, and part of the light-modulating pixels record sync signals in two or more positions on the hologram recording medium with retaining a predetermined interval, thereby improving hindrance to reproduction or readout of information recorded on the hologram recording medium, a decrease in S/N, and so on due to deformation or the like of the hologram recording medium.

Hologram recording method, hologram recording reproduction method, hologram recording device, hologram recording/reproduction device and hologram reproduction device

Growing community of inventors

Saitama, Japan

Tomiji Tanaka