Abstract: A reproduction apparatus is provided which reproduces, from a hologram recording medium on which digital data are recorded as an element hologram formed from interference fringes generated by interference of imaged data of the digital data as object light with reference light, the digital data. If a synchronization signal recorded in advance in a predetermined region of the hologram recording medium is detected successfully, then it is decided that the tracking state with regard to the element hologram is favorable. In this instance, signal processing is performed the image picked up from the element hologram to reproduce the digital data.

Abstract: A lens-less system for analyzing an optical spectrum includes a sophisticated volume hologram for separating an incident diffuse optical signal into wavelength channels without aid of an external collector lens and a detector for receiving and detecting light dispersed by the sophisticated volume hologram. Other systems and methods are also provided.

Abstract: A beam scanning device includes a light source to emit a light beam, an optical deflector to deflect the light beam, and an optical system including a f? lens to guide the defected light beam to a scan surface to form an image thereon. The beam scanning device also includes a synchronization detecting sensor to detect the deflected light beam outside an area of the image, a light blocking member configured to block the deflected light beam on an exit side of the f? lens outside an effective scan area that includes the area of the image and also includes an optical path extending to the synchronization detecting sensor. The beam scanning device further includes a metal housing accommodating the light source, the optical deflector, the optical system, the light blocking member, and the synchronization detecting sensor.

Abstract: An optical beam transformation system has a sequence of optical elements arranged along an optical axis of the optical beam transformation system and designed for transforming an entrance light distribution striking an entrance surface of the optical beam transformation system into an exit light distribution emerging from an exit surface of the optical beam transformation system by radial redistribution of light intensity. The optical elements include a transformation element causing a radial redistribution of light intensity and having a transformation surface inclined to the optical axis and causing a polarization-selective reflection of a light distribution incident on the transformation surface according to an efficiency symmetry characteristic for the transformation surface.

Abstract: A polariser or a system for lighting using such a polariser in a polarisation recuperation system. The polariser comprises first and second polarising beam splitters (212a, 212b) for splitting first and second unpolarised beams each into at least first and second polarised beams of different polarisation states. The first and second polarised beams are guided to first and second light paths respectively. On these light paths controllable polarisation conversion elements (218a, 218b) are arranged such that the second polarised beam from the first unpolarised beam time-shares a same path through the polarisation conversion element (218a, 218b) as the first polarised beam from the second unpolarised beam. The controllable polarisation conversion elements are switchable to alternately convert and not convert the polarisation state, depending on which beam is switched to pass through the polarisation conversion elements (218a, 218b), corresponding with which of the first or second unpolarised beams are present.

Abstract: A device for optically scanning media or objects includes a mirror which deflects light beams and is coupled to a drive unit. The deflection mirror can be rotated with a mirror normal being tilted relative to the axis of rotation. An area can be scanned quickly at a large aperture such that the device is particularly suitable for use in optical remote sensing systems or remote locating systems, such as for gases, especially hydrocarbons in the atmosphere.

Abstract: Even when a tilt error is caused in a holographic memory in a direction perpendicular to a surface including optical axes of a signal beam and a reference beam, the signal beam and the reference beam are allowed to enter the holographic memory at adequate angles relative thereto at all times by suppression of the tilt error. During recording and reproducing operations, the reference incident angle of the reference beam in the radial tilt direction is detected based on a received light state. A tilt actuator for displacing the holographic memory medium in the radial tilt direction is driven to adjust an incident angle of the reference beam in the radial tilt direction to the reference angle Sr. Then, the signal beam and the reference beam are emitted to the holographic memory medium to execute the recording and reproducing operations.

Abstract: An optical scanning device includes a deflector that deflects light fluxes emitted from light sources and rotates in a first direction, optical systems that direct deflected light fluxes onto subject surfaces, and a member that prevents a flare beam reflected by one of the optical systems from entering another one of the optical systems. The deflector includes first edges in the first direction and the member includes second edges arranged in a second direction perpendicular to the first direction. The second edges are out of alignment with each other in the first direction so that a first edge does not pass all of the second edges simultaneously.

Abstract: The optical scanning apparatus includes a polygonal rotatable mirror which deflects a light beam emitted from a light source, a drive motor which rotates said polygonal rotatable mirror, and an optical box which holds said drive motor, wherein a fitting hole in which a bearing of said drive motor fits, is provided in said optical box, and a wall surface of this fitting hole has notch portions partially arranged. Thereby, the heat release property of the bearing of the polygonal rotatable mirror drive motor becomes good.

Abstract: In the present wire grid polarization element unit and polarized light emitting apparatus, it is possible to prevent non-polarized light, which has bad extinction ratio from leaking from end portions of polarization elements. Specifically, in a frame, wire grid polarization elements are aligned and light shielding members are provided on end portions of the polarization elements. In addition, without the shielding members, the wire grid polarization elements may be overlapped each other. Further, a rotation unit may be provided in order to rotate the polarization elements with respect to an optical axis of light so that a direction of grid of each polarization element can be parallel to each other.

Abstract: A device for linear scanning includes a roof prism. The roof prism includes a roof of two mutually perpendicular reflecting surfaces intersecting in a line of intersection. A scanning mechanism moves the roof prism in a direction perpendicular to a plane of bilateral symmetry. The line of intersection is included in the plane of bilateral symmetry; and an incident beam entering the prism and an exit beam exiting the prism are angularly separated by a substantial angle. Preferably, the scanning mechanism generates periodic motion or rotational motion of the roof prism with a radius of motion greater than a dimension of the roof prism.

Abstract: A color wheel including a motor body, a housing, a spacer and a color filter. In this case, the housing is set to a side of the central axis of the motor body. The spacer is placed over the housing. The color filter is set on one side of the spacer, which is opposite the housing, so that there is a recess between the color filter and the housing.

Abstract: An optical device including an optical waveguide upon which a group of parallel light beams different in traveling direction from each other are incident and from which the group of parallel light beams go out after propagated by repeated total reflection through it. The optical waveguide includes a first reflection-type volume hologram grating, and a second reflection-type volume hologram grating. The pitches of interference fringes on the hologram surfaces of the first and second reflection-type volume hologram gratings are equal to each other. In at least the second reflection-type volume hologram grating, the angle formed between the interference fringes and hologram surfaces are varied continuously or stepwise within the hologram in relation to the main incident light beam so as to meet the Bragg condition. Therefore, it is possible to reduce the unevenness of color and brightness due to angles of view.

Abstract: A color wheel is provided for use in the illumination system of a projector. The color wheel includes a rotor and a motor for rotating the rotor, the rotor includes a ring shaped translucent area formed by color filter segments, the translucent area being adapted to continuously extend into a light path as the rotor is rotated, the rotor in a first plane perpendicular to the axis of rotation further includes first means for balancing, the rotor in a second plane perpendicular to the axis of rotation further includes second means for balancing, wherein the first and the second plane are spaced apart. Due to the dual plane balancing means, the color wheel is better balanced.

Abstract: A scanning optical delay line includes an optical path element that rotates about its central axis, such that a face is intermittently incident a beam of light to be optically delayed. When the beam is not incident the face, it is reflected onto a reinsertion line which provides a second opportunity for the beam to intersect the optical path element. The optical path element may include one or more parallelogram prisms, or parallel reflective surfaces to provide a substantially linear optical path length variation during the scan, which is produced by the rotation of the optical path element. A highly linear part of the rotation can be maximally used providing a high duty cycle, high linearity scanning optical delay line that permits high quality, high data rate applications.

Abstract: An optical beam scanning device is configured from a deflecting unit that has a function to support a deflecting member and a light source, including an exposing semiconductor laser, a polygon mirror, a first f? lens and a second f? lens, and strictly regulate their position relative to each other; and a support member that has a function to support a mirror, a second cylindrical lens and a AD sensor along with the deflecting unit, and appropriately position them relative to a photoreceptor drum; and a housing that has a function to cover the outer portion of the deflecting unit and the support member, along with strengthening the support member.

Abstract: A process for producing a low-visibility retroreflective visual tag, which can be used to identify and/or determine the position of an object. This process involves placing an infra-red-blocking material over a retroreflective substrate to form the low-visibility retroreflective visual tag. This infra-red-blocking material is placed so as to form a pattern, which becomes visible to an infrared sensor when the low-visibility retroreflective visual tag is illuminated by an infra-red light source.

Abstract: An optical scanning system includes a deflecting device to scanningly deflect a light beam from a light source in a main scan direction, and an imaging optical system for imaging, upon a surface to be scanned, the light beam deflected by a deflecting surface of the deflecting device. First and second differences in wavefront aberration are respectively produced as a result of reflection by the deflecting surface and as a result of transmission through the imaging optical system. At least one optical surface inside the imaging optical system is non-arcuate in a main scan section, so as to assure that the first and second phase differences are made opposite to each other.

Abstract: An image scanning apparatus for realizing an image on a screen includes: a spatial light modulator module for diffracting light beams having different wavelengths into relevant modes; and an iris for limiting light beams of modes except a mode of 0th-order among the modes diffracted by the spatial light modulator module.

Abstract: By way of example, it would also be possible to dispense in a manner which is not illustrated with the spring elements 2, and then for the element 1 to carry out an oscillating translational deflection. Micromechanical optical elements have a reflective surface which can be deflected electrostatically or electromagnetically in a known manner and which can be used for a large number of applications. The objective is to provide an element such as this at low cost and with improved dynamic deformation behaviour. The elements with a reflective surface are in this case held by spring elements, in which case the element which can be deflected is held on mutually opposite sides by in each case at least two mutually independent spring elements.