Sony Corporation

Kazutatsu Tokuyama

Kenji Tanaka

Masaaki Hara

Yoshiki Okamoto

Akio Yamakawa

Mitsuru Toishi

Koji Takasaki

Hideo Nagasaka

Shinji Yamada

Hitoshi Okada

Katsuyuki Akutsu

Tomiji Tanaka

Satoru Seko

Mikio Sugiki

Takashi Mizusawa

Kazuyuki Hirooka

Yusuke Kajio

Hideo Nagasaki

Daisuke Tsukuda

In some embodiments, a head mounted display is provided, comprising a light guide, at least first and second diffraction gratings, alignment marks Aand Bassociated with the first diffraction grating, and alignment marks Aand Bassociated with the second diffraction grating. The first diffraction grating may be disposed on a first surface of the light guide, the first surface facing away from a light input. The second diffraction grating may be disposed on a second surface of the light guide, the second surface facing towards the light input. The second diffraction grating may be adapted to diffract at least some of the light input into the light guide, and the first diffraction grating may be adapted to diffract at least some light transmitted through the light guide back into the light guide.

Optical device, head mounted display, assembling method for the same, holographic diffraction grating, display device, and alignment device

A light irradiation device includes: a focus servo control unit including a light source, a spatial light modulating unit, and a light irradiating unit, for focus servo control so that the ideal focal position of light via an objective lens is such that distance between an ideal focal position and a hologram recording medium surface is smaller than distance from the surface to the lower layer side face of the recording layer, and the focal position of light via the objective lens is constant at the ideal focal position; an objective-lens/relay-lens distance adjusting unit to adjust distance between the objective lens and a relay lens close to the objective lens; a light reception unit to receive marker light; and a constant distance control unit to control the objective-lens/relay-lens distance adjusting unit based on error between the ideal position of the marker light, and the actual position of the marker light.

Light irradiation device for recording information in a hologram recording medium

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 device includes: a light source for applying light to a hologram recording medium having a recording layer in which information recording is performed by interference fringes between signal light and reference light; a spatial modulation unit that generates the signal light and/or the reference light and generates a marker light in a predetermined position within an incident surface of the light from the light source by performing spatial light modulation on the light from the light source; a light applying unit that applies the light subjected to spatial light modulation by the spatial light modulation unit to the hologram recording medium via an objective lens; a light receiving unit that receives the light applied via the objective lens through the hologram recording medium; and a tilt detection unit that obtains a tilt error signal representing an error from an ideal angle of a tilt angle as an incident angle of the applied light via the objective lens to an information recording surface of the hologram recording medium based on a result of detection of an error between an ideal light reception position of the marker light in the light receiving unit and a real light reception position of the marker light by the light receiving unit.

Hologram device, tilt detection method, and tilt correction method

A hologram recording/reproducing apparatus records data as a hologram by applying signal and reference light beams to a hologram-recording medium, obtains a diffracted light beam by applying a reproduction light beam to the hologram, and reproduces the data using the diffracted light beam. The hologram recording/reproducing apparatus includes an external-cavity light source, a polarization-control element that changes a polarization angle of a light beam emitted from the external-cavity light source, a polarizing-beam-splitting element that splits the light beam to obtain two light beams and that changes a ratio between amounts of the two light beams, a photoreceptor that receives one of the two light beams, a spatial light modulator that receives the other beam and that generates signal, reference, and reproduction light beams, and a control unit that changes the polarization angle or polarization state of the light beam.

Hologram recording/reproducing apparatus and light source apparatus

In a reproducing apparatus adapted to reproduce data recorded on a holographic recording medium, a reference light generator generates reference light for illuminating the holographic recording medium, and a coherent light generator generates coherent light having an intensity greater than the absolute value of a minimum amplitude of a reproduced image and having a phase equal to the phase of the reproduced image. An image signal acquisition unit senses the reproduced image produced by illuminating the holographic recording medium with the reference light and the coherent light, and acquires an image signal based on the reproduced image. A square root calculation unit calculates the square root of each of values constituting the image signal. A removal unit removes the component of the coherent light from the calculated square root, whereby the data recorded on the holographic recording medium is correctly reproduced.

Reproducing apparatus and reproducing method

A recording and reproducing apparatus for recording data to and reproducing data from a hologram recording medium is provided. The recording and reproducing apparatus includes a light emitting unit for emitting light to be directed to the recording medium set at a predetermined position, a spatial light modulation unit for performing spatial light modulation on incident light by pixels, an image sensor for receiving incident light by pixels and converting the incident light into an electrical signal, an optical system for guiding the light emitted by the light emitting unit to the recording medium via the spatial light modulation unit while guiding, to the image sensor, light reflected from the recording medium in response to the light emitted by the light emitting unit, and a determination unit for controlling the spatial light modulation unit.

Recording and reproducing apparatus and defect determination method

A hologram reproducing apparatus includes a reference-light spatial-light modulating section that displays a reference light pattern for generating reference light, an image sensor that has pixels arrayed two-dimensionally that receive diffractive light generated by irradiating the reference light on a hologram recording medium, and a control unit that processes an electric signal from the image sensor and reproduces recording data. The control unit detects a predetermined area electric signal, detects a hologram electric signal, subtracts the predetermined area electric signal from the hologram electric signal to obtain a reproduced signal after noise reduction, and reproduces the recording data from the reproduced signal after noise reduction.

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Tokyo, Japan

Kazutatsu Tokuyama