摘要:
A display apparatus of the invention includes: a plurality of display devices arranged in one direction, each of the plurality of display devices having a display area; and a plurality of image transmission means corresponding to the respective display devices, one end face of each of the image transmission means being coupled to a display area of the corresponding one of the display devices, other end faces of the image transmission means corresponding to the adjacent ones of the display devices being in contact with each other, the plurality of image transmission means being bent toward the one direction in which the display devices are arranged. Alternatively, a display apparatus of the invention includes: a plurality of display devices disposed in two directions, each of the plurality of display devices having a display area; a plurality of image transmission means corresponding to the respective display devices, one end face of each of the image transmission means being coupled to a display area of the corresponding one of the display devices, other end faces of the image transmission means corresponding to the adjacent ones of the display devices being in contact with each other, some of the plurality of image transmission means each having inward facing slopes and outward facing slopes on two pairs of opposing faces, the outward facing slopes of the image transmission means being directed to a direction in which the corresponding display device has no adjacent display devices.
摘要:
An optical pickup apparatus comprising a diffraction device in which a laser beam from a light source is diffracted by the diffraction device to produce a main beam and two sub-beams which are focused on a recording medium, the beams reflected from the recording medium aare diffracted by the diffraction device to be directed to at least one photodetector, whereby a tracking error signal can be detected from output signals of the photodetector by the three-spot method that is so highly reliable that an offset never arises in the tracking error signal even when the optical axis of the optical system is displaced from a given position.
摘要:
A polarization diffraction element comprising two diffraction gratings formed on both faces of a substrate respectively. Both the diffraction gratings have grating lines which are arranged at the same grating pitch, and whose directions mutually form a predetermined minute angle. The grating lines may also be arranged parallel to each other. In this case, the relationship between grating pitches D.sub.1, D.sub.2 of the respective diffraction gratings and the wavelength .lambda. of an incident light is expressed as:0
摘要:
The invention discloses an optical head device having a diffraction grating element divided into a plurality of diffraction gratings have a substantially equal diffraction angle, a substantially equal optical utilization efficiency, and different focal distances of first order diffracted lights, each of the first order diffracted lights being produced from a reflected light from the recording medium, at the respective diffraction gratings and a photodetector positioned at a mid-position between two focal points produced when there occurs no focusing error, the photo-detecting means having a plurality of photo-detecting parts juxtaposed in a direction substantially orthogonal to an average diffracting direction of the diffraction grating element. The above arrangement enables to produce a small size optical head device and improve the detecting of focusing errors and tracking errors.
摘要:
A polarization detector includes a polarization diffraction element having a substrate with two facing surfaces which are placed in parallel with each other, a first diffraction grating formed on one surface of the substrate, and a second diffraction grating formed on the other surface of the substrate, with light being incident upon the first diffraction grating. Further, each grating pitch of the first diffraction grating and the second diffraction grating are nearly equal to a wavelength of the incident light. A limiting member is also included for limiting an incident region of the incident light with respect to the polarization diffraction element. The limiting member is formed on a light incident side of the first diffraction grating. Further, a converging lens is included for respectively converging light transmitted through the first diffraction grating and the second diffraction grating and light diffracted by the first diffraction grating and the second diffraction grating into different beam spots. Finally, a pair of photodetectors are included for detecting each optical intensity of the two beam spots converged by the converging lens.
摘要:
An optical element comprises a polarization diffraction element that is provided with diffraction gratings that are respectively mounted on different faces of a transparent substrate of a flat plate shape, which grating pitches are equal to each other and approximately equal to the wavelength of an incident light, and which grating lines are parallel. The thickness of the substrate is set such that the difference that occurs between the phases of the P and S polarizations of a light due to the grating, and the difference that occurs between the phases of the two polarizations when the light propagates through the substrate cancel out. The optical pickup device comprising the optical element includes a polarized light detecting unit provided with a diffraction grating which grating pitch is approximately equal to the wavelength of an incident light; a first photodetector that is mounted integrally and virtually in parallel with the substrate, and that receives a zero-order diffracted light produced by the diffraction grating; and a second photodetector that is located in the same plane as the first photodetector and mounted integrally with the first photodetector and the substrate, and that receives a first-order diffracted light produced by the diffraction grating.
摘要:
A three-dimensional image display apparatus which includes a plurality of display devices, a first optical arrangement for synthesizing a plurality of images from the image display devices, a second optical arrangement for changing a position where at least one of the images is projected, the first and second optical arrangement synthesizing a plurality of images formed at different positions.
摘要:
The method of manufacturing an optical diffraction grating element of the present invention is characterized in adopting an ion beam made from a gas chemically reacting with a glass substrate when forming a diffraction grating having a serrated profile upon the glass substrate through an ion beam etching method. Also, when manufacturing an optical diffraction grating element that is divided into a plurality of regions whereon diffraction gratings having different diffraction angles with respect to an incident light are provided, the method of the present invention is characterized in forming slits into a resist film disposed upon a transparent substrate such as a glass substrate, in accordance with the patterns of the diffraction gratings, such that the width of the slits is constant irrespectively of the regions. Accordingly, the method of manufacturing an optical diffraction grating element of the present invention enables to improve the diffraction efficiency of the optical diffraction grating element, and to enhance the optical efficiency of an optical head device. The SN ratio of the output signals released by the optical head device may be thus improved and the servo error control executed accurately.
摘要:
An optical diffraction grating element comprising diffraction gratings having a configuration in which grooves and flat lands each positioned between the adjacent grooves are successively alternately formed, wherein the diffraction gratings have the same groove depth, groove width and groove tilt angle in order to obtain a constant 0th-order diffraction efficiency and first-order diffraction efficiency in the optical diffraction grating element while the pitches of the diffraction gratings are made different by setting a different land width for each diffraction grating.
摘要:
An optical pickup apparatus for reading out information from an optical disk. The optical pickup includes a light source; and an optical device having a grating pattern for splitting a light beam from said the source into a zero-order diffracted beam and plus and minus first-order diffracted beams. The grating pattern has the center portion and one or more side portions. The efficiency of the center portion for the zero-order diffracted beam is greater than the efficiency of the side portions for the zero-order diffracted beam.