Abstract: A disclosed polarization beam splitter is effective when light to undergo polarization-splitting has an incidence angle that falls in a range of 54 degrees through 66 degrees. The polarization beam splitter includes, between two transparent substrates, an adhesive layer configured to adhere to a first transparent substrate of the two transparent substrates, two or more types of dielectric multilayer films having different design basis wavelengths, and a single-layer dielectric film. The dielectric multilayer films and the single-layer dielectric film form a polarization split film, which performs a polarization split function with respect to light that is substantially in the visible wavelength region.

Abstract: An imaging device includes a lens array including multiple lenses facing a subject; an image sensor obtaining a compound-eye image including single-eye images of the subject formed by the lenses; and a computing unit processing the compound-eye image obtained by the image sensor. The lenses have different radii of curvature and substantially the same back focal length, and the computing unit extracts an in-focus image from the compound-eye image.

Abstract: An image projecting device, including an image forming element for forming an image, a light source for generating light, and an imaging optical system for imaging an image formed by the image forming element on a screen, a first prism having a first transmission surface for transmitting light generated from the light source therethrough, a reflection curved surface being a curved surface for directly reflecting light having transmitted through the first transmission surface, a reflection-transmission surface for directly reflecting light reflected from the reflection curved surface to the image forming element and transmitting light reflected from the image forming element therethrough, and a second transmission surface for transmitting light reflected from the reflection-transmission surface and light reflected from the image forming element therethrough, and a second prism for directing light having transmitted through the reflection-transmission surface of the first prism to the imaging optical system.

Abstract: A polarization conversion element having plural polarization separation sections and plural phase modulation sections is disclosed. A light flux is separated into transmission light (P polarization) and reflection light (S polarization) by being input to a polarization separation section. The reflection light reflected at the polarization separation section is output in the same direction as that of the transmission light by being reflected again at an adjacent polarization separation section at a different position from a position where a light flux is input to the adjacent polarization separation section. The phase modulation section is disposed on an optical path of the transmission light or the reflection light and output light becomes the same polarization.

Abstract: A disclosed polarization beam splitter is effective when light to undergo polarization-splitting has an incidence angle that falls in a range of 54 degrees through 66 degrees. The polarization beam splitter includes, between two transparent substrates, an adhesive layer configured to adhere to a first transparent substrate of the two transparent substrates, two or more types of dielectric multilayer films having different design basis wavelengths, and a single-layer dielectric film. The dielectric multilayer films and the single-layer dielectric film form a polarization split film, which performs a polarization split function with respect to light that is substantially in the visible wavelength region.

Abstract: A variable optical attenuator is disclosed which comprises a plane-parallel birefringent element for separation/synthesis which separates light beams having orthogonal polarization directions on the same optical path, the birefringent element synthesizing light beams on different optical paths; a light converging lens disposed adjacent to the birefringent element for separation/synthesis; a reflecting mirror disposed at a focal point of the lens opposite to the birefringent element for separation/synthesis with respect to the lens; a variable polarization rotating device; and an input port and an output port which are disposed at the end of the birefringent element for separation/synthesis; the variable polarization rotating device being disposed at any position between the birefringent element for separation/synthesis and the reflecting mirror, the variable polarization rotating device controlling the rotational angle of the polarization direction of incident light beams from the input port, to thereby contr

Abstract: A variable optical gain equalizer in accordance with one embodiment of the present invention comprises a variable branching ratio beam splitter having a variable polarization rotator, the variable branching ratio beam splitter branching an input light beam into two light beams at an arbitrary power ratio, through control of the rotation angle of the polarization direction by the variable polarization rotator; an optical filter presenting different filter characteristics to the two branched output light beams; and a polarization coupler for polarization coupling the two light beams that have passed through the optical filter, wherein the rotation angle of the polarization direction is controlled by the variable polarization rotator so as to vary the spectra of the output light beams.

Abstract: A variable optical attenuator is disclosed which comprises a plane-parallel birefringent element for separation/synthesis which separates light beams having orthogonal polarization directions on the same optical path, the birefringent element synthesizing light beams on different optical paths; a light converging lens disposed adjacent to the birefringent element for separation/synthesis; a reflecting mirror disposed at a focal point of the lens opposite to the birefringent element for separation/synthesis with respect to the lens; a variable polarization rotating device; and an input port and an output port which are disposed at the end of the birefringent element for separation/synthesis; the variable polarization rotating device being disposed at any position between the birefringent element for separation/synthesis and the reflecting mirror, the variable polarization rotating device controlling the rotational angle of the polarization direction of incident light beams from the input port, to thereby contr

Abstract: A variable optical gain equalizer in accordance with one embodiment of the present invention comprises a variable branching ratio beam splitter having a variable polarization rotator, the variable branching ratio beam splitter branching an input light beam into two light beams at an arbitrary power ratio, through control of the rotation angle of the polarization direction by the variable polarization rotator; an optical filter presenting different filter characteristics to the two branched output light beams; and a polarization coupler for polarization coupling the two light beams that have passed through the optical filter, wherein the rotation angle of the polarization direction is controlled by the variable polarization rotator so as to vary the spectra of the output light beams.

Abstract: A plurality of first cylindrical lenses aligned in an array, having a collecting function with respect to an alignment direction parallel to the array, to collect luminous flux from a body to be imaged. A first reflective collector-surface having a reflective collecting function with respect to a perpendicular direction perpendicular to the alignment direction collects the luminous flux from the plurality of first cylindrical lenses, and provides a collected parallel luminous flux to a plurality of roof-mirror type reflective plane-pairs or to a plurality of right-angle prisms. The plurality of roof-mirror type reflective plane-pairs or right-angle prisms reflects the luminous flux toward a second reflective collector-surface disposed for convergence of the luminous flux with respect to the perpendicular direction.

Abstract: An imaging device includes a lens array in which lenses are arranged in a line, the lenses being optically equivalent, a roof mirror array having roof mirrors arranged in a line parallel to a direction in which axes of the lenses of the lens array are arranged, and an aperture member having apertures arranged so as to correspond to the lenses of the lens array. The center of an interval between axes of adjacent lenses of the lens array corresponds to a ridge line of the roof mirror array, and wherein at least two roof mirrors are provided with respect to each of the lenses of the lens array.

Abstract: A twin-core ferrule structure is provided which is miniaturized in size, facilitated for accurate positioning the optical axes of two optical fibers, and improved both in degree of freedom of determining a shape and in high-volume productivity.

Abstract: An imaging device includes a first focusing element on which rays from an object are incident, a second focusing element from which the rays are emitted toward an imaging surface, and a roof mirror having surfaces which are connected to each other at an angle of 90.degree. so that a ridge line is formed, the roof mirror being arranged so that the ridge line intersects optical axes of the first focusing element and the second focusing element at a position on a plane including the optical axes.

Abstract: In a bus arbiter connected to a system bus of a multi-processor system having a plurality of modules respectively having processors, a first unit detects an abnormality in the multi-processor system on the basis of an internal state of the bus arbiter and a predetermined signal transferred via the system bus. A second unit initializes the internal state of the bus arbiter to restart the bus arbiter when the first unit detects an abnormality.

Abstract: A servo method in a multibeam optical pickup in which, at the time of a recording mode, a record information is confirmed and reproduced by a beam for reproduction while the record information is written by a beam for record, and the record information is reproduced by the beam for reproduction at the time of a reproducing mode, comprises the steps of detecting a focus servo signal and a track servo signal with respect to each of the beams for record and reproduction reflected by an optical disk; performing focusing and tracking operations based on the focus servo signal and the track servo signal provided by the beam for record at the time of the recording mode; and performing the focusing and tracking operations based on the focus servo signal and the track servo signal provided by the beam for reproduction at the time of the reproducing mode. In another servo method, the focusing and tracking operations may be performed according to the recording and reproducing modes.