Abstract: A light irradiation device for emitting light of two or more components by laser light, which a laser light source emits, to an outside, includes a diffusion optical path change member configured to convert a first color component of the laser light into diffusion light and change an optical path of the first color component; a phosphor configured to generate fluorescence of a second color component different from the first color component based on the laser light, and change an optical path of the second color component; and an optical path switch member configured to switch between a first optical path for emitting the first color component to the outside and a second optical path for emitting the second color component to the outside. Light going straight at a light diffusion position of the diffusion optical path change member is not emitted to the outside.

Abstract: A light irradiation device for emitting light of two or more components by laser light, which a laser light source emits, to an outside, includes a diffusion optical path change member configured to convert a first color component of the laser light into diffusion light and change an optical path of the first color component; a phosphor configured to generate fluorescence of a second color component different from the first color component based on the laser light, and change an optical path of the second color component; and an optical path switch member configured to switch between a first optical path for emitting the first color component to the outside and a second optical path for emitting the second color component to the outside. Light going straight at a light diffusion position of the diffusion optical path change member is not emitted to the outside.

Abstract: A linear solar energy collector system includes reflective lines arranged in parallel in a south-north direction, heliostats mounted on the reflective lines, respectively, each comprised of mirror segments to reflect solar radiation, a light receiving line set above the reflective lines in a east-west direction, a receiver mounted on the light receiving line, to receive light reflected from the heliostats and collect heat from the light, and an angular adjuster to adjust angles of the mirror segments individually to irradiate a same light receiving area on the receiver with the reflected light from east-west neighboring reflective lines and thereby adjust a concentration ratio.

Abstract: A light source unit comprises a plurality of light sources emitting a plurality of light beams. A plurality of volume hologram elements are provided for the plurality of light sources respectively, each volume hologram element having a plane of incidence of an incoming light beam and a plane of outgoing radiation of a diffracted light beam which are perpendicular to each other, the plurality of volume hologram elements having mutually different Bragg conditions in which an optical intensity of a diffracted light beam is set to a maximum.

Abstract: A tilt sensor for detecting information related to a tilt of an object to a reference plane is disclosed. The tilt sensor includes a diffraction element disposed that diffracts an incident light at diffraction efficiency depending on the incident angle, and a photo detector that detects a diffraction light diffracted by said diffraction element and outputs an photoelectric signal. Since the diffraction efficiency of the diffraction element changes as the incident angle changes, the intensity of the diffraction light from the diffraction element changes. As a result, the photoelectric signal output from the photo detector contains the information related to the tilt of the object.

Abstract: A light source unit comprises a plurality of light sources emitting a plurality of light beams. A plurality of volume hologram elements are provided for the plurality of light sources respectively, each volume hologram element having a plane of incidence of an incoming light beam and a plane of outgoing radiation of a diffracted light beam which are perpendicular to each other, the plurality of volume hologram elements having mutually different Bragg conditions in which an optical intensity of a diffracted light beam is set to a maximum.

Abstract: An optical head is used to irradiate a beam onto an optical recording medium having multiple recording positions in the thickness direction, and to receive a reflection beam reflected from the recording medium. The optical head has a light source, an optical system, and a detector. The optical system transmits the irradiation beam from the light source to the recording positions of the medium, separates optical components based on wavelength, and transmits the components to respective detection positions, where the components are individually detected.

Abstract: A light source unit outputs a plurality of light beams and includes a plurality of light sources, a plane hologram element, and a plurality of volume hologram elements. The plurality of light sources emits the plurality of light beams. The plane hologram element is provided on optical paths of the plurality of light beams emitted by the plurality of the light sources, and diffracts the plurality of light beams. The plurality of volume hologram elements corresponds to the plurality of light sources, respectively, and is provided on the optical paths of the plurality of light beams traveling from the plurality of light sources to the plurality of volume hologram elements via the plane hologram element.

Abstract: A polarization diffraction grating includes two media having different orientation states arranged alternately and cyclically, wherein each boundary between the media forms an oblique rectangular shape.

Abstract: An optical pickup apparatus couples light beams, and corrects a chromatic aberration and a spherical aberration. A coupling lens includes groups of lenses common to the light sources so as to converge a light beam from each of the light sources. An aperture changes an aperture diameter for the light beam, which has been converged by the coupling lens, in accordance with one of the light sources from which the light beam is emitted. An objective lens converges the light beam onto a recording surface of one of the optical information recording media corresponding to the one of the light sources that emits the light beam. A lens moving mechanism moves at least one group of lenses from among the groups of lenses of the coupling lens in a direction of an optical axis thereof in accordance with an aperture diameter of the aperture.

Abstract: A tilt sensor for detecting information related to a tilt of an object to a reference plane is disclosed. The tilt sensor includes a diffraction element disposed that diffracts an incident light at diffraction efficiency depending on the incident angle, and a photo detector that detects a diffraction light diffracted by said diffraction element and outputs an photoelectric signal. Since the diffraction efficiency of the diffraction element changes as the incident angle changes, the intensity of the diffraction light from the diffraction element changes. As a result, the photoelectric signal output from the photo detector contains the information related to the tilt of the object.

Abstract: A polarization diffraction grating includes two media having different orientation states arranged alternately and cyclically, wherein each boundary between the media forms an oblique rectangular shape.

Abstract: An optical pickup device includes a light source unit an optical system which leads a return light beam to a predetermined light-receiving location and includes an object lens focusing each light beam from the light source unit to a recording surface of a corresponding storage medium and a photodetector arranged at the light-receiving location. The light source unit includes a plurality of light sources outputting light beams respectively, the plurality of light sources being arranged in proximity to each other, and a divergence-angle changing unit changing an angle of divergence of a light beam output from at least one of the plurality of light sources.

Abstract: An objective lens causes light emitted from the light source to converged onto an optical recording medium. A beam splitter separates light, reflected from the optical recording medium, from the bundle of rays emitted from the light source. A detective lens causes the light separated by means of the beam splitter to be converged. A detective photosensitive element is disposed at a position at which the light converged by means of the detective lens approximately converges. The detective lens has a first and second surfaces. The first surface faces the beam splitter and is formed to be convex so as to cause the bundle of rays to converge. The second surface comprises two surfaces which are combined with one another so that the line of intersection, formed where the two surfaces meet, does not intersect the axis associated with the convexity of the first surface.

Abstract: A focus error signal detection device comprising an optical system for guiding a reflection beam reflected from an optical information recording medium to a photo-detection system side. A beam dividing system is arranged for dividing the reflection beam to two beams. Two photo-detecting units are arranged for detecting the two divided beams, respectively, each unit having light receiving surfaces arranged on a same plane. A beam position adjusting system is arranged for adjusting optical axes of the two divided beams with respect to predetermined positions of the photo-detecting units by simultaneously moving the two detecting units with respect to the beam dividing system.

Abstract: An optomagnetic information recording and reproducing apparatus includes an optomagnetic optical pick-up for recording or reproducing information on or from an optomagnetic information recording disc. An optomagnetic optical pick-up includes a first diffraction grating for receiving light reflected from the disc and separating the light into a first transmitting light which transmits through the first diffraction grating beam and a first diffracted light beam which is diffracted by the first diffraction grating. A second diffraction grating is disposed to receive the first transmitging and diffracted light beams and discharges a second transmitting light beam and a second diffracted light beam. A tracking error detector is provided to receive the second transmitting light beam and a focusing error detector is disposed to receive the second diffracted light beam. An optomagnetic signal is obtained as a difference between outputs from the tracking and focusing error detectors.

Abstract: A parallel image processing apparatus includes (1) a light diffusing layer, (2) a photoelectric conversion layer which receives diffused light from the diffusion layer, and (3) an edge detection layer which receives signals from conversion elements in the conversion layer, and generates edge information which defines the edge of object(s) imaged on the light diffusing layer. The conversion layer includes pairs of conversion elements, the pairs having a center element and a peripheral element surrounding it. Signals from one or more center elements are summed, the sum being differentially amplified with a sum of signals from one or more peripheral elements to arrive at an edge signal. Edge signals may be used to differentiate among characters, pictures or photographs, and a blank images.

Abstract: An optomagnetic information recording and reproducing apparatus includes an optomagnetic optical pick-up for recording or reproducing information on or from an optomagnetic information recording disc. An optomagnetic optical pick-up includes a first diffraction grating for receiving light reflected from the disc and separating the light into a first transmitting light which transmits through the first diffraction grating beam and a first diffracted light beam which is diffracted by the first diffraction grating. A second diffraction grating is disposed to receive the first transmitting and diffracted light beams and discharges a second transmitting light beam and a second diffracted light beam. A tracking error detector is provided to receive the second transmitting light beam and a focusing error detector is disposed to receive the second diffracted light beam. An optomagnetic signal is obtained as a difference between outputs from the tracking and focusing error detectors.

Abstract: An optical information recording/reproducing apparatus comprises a semi-reflecting means which receives a emitted laser light emitted from a light source, which reflect partially the received laser light toward an optical information recording medium in order to record an information, and which transmits a reflected laser light reflected by the optical information recording medium, a separating means which has the semi-reflecting means on one surface thereof, which diffracts a part of the transmitted laser light, transmits the other part of the transmitted laser light, and then subsequently diffracts said diffracted light again to produce twice diffracted light and transmits said transmitted light again to produce twice transmitted light, and a detecting means which detects the diffracted laser light and the transmitted laser light to thereby generate an information reproduction signal, a track error signal and a focus error signal.

Abstract: An optical information reading and writing device comprising a laser source which emits a laser beam for irradiating an optical recording disk to record an information therein and an optical signal detection system which receives a reflection beam reflected from the disk surface and controls position of the disk. The optical signal detection system comprises a condenser lens for converging the reflection beam and a dual grating element which has linear diffraction gratings formed on its both side surfaces. The incident side grating divides the reflection beam to two beams, one being a beam which is diffracted by the grating and the other being a beam which passes substantially straight through the grating without being diffracted thereby. The optical signal detection system further comprises a pair of three-segment light receiving detector elements for detecting the divided two beams. The two detector elements are disposed on a same plane.