Abstract: A zoom lens, for use in a telescope at infra-red wavelengths or single wavelength visible light, provides a magnification which may be adjusted to either of two predetermined values. The lens comprises a pair (14) of similar elements (15, 16) fixed relative to one another and each having an aspheric convex surface with the aspheric surfaces of the pair of elements outermost. The pair of elements (14) is located between the two image planes formed in the telescope and is movable between two conjugate positions.

Abstract: A reflective mirror having a cooling unit attached thereto is provided with a layer of material deposited on the surface of a glass plate. This material has such properties that most of ultraviolet rays in a light beam emitted from a light source are reflected from the reflective surface of the reflective mirror (cold mirror) but infrared rays permit to permeate through the reflective mirror or are absorbed in the substrate of the reflective mirror. The cooling unit is disposed on the opposite side to the reflective surface of the reflective mirror to absorptively remove infrared rays emitted from the light source. The reflective mirror is preferably employable for an exposing equipment in which the reflective mirror of the present invention and a plurality of conventional reflective mirrors each made of an ordinary metallic material are arranged as essential components with a lower working temperature.

Abstract: Edge enhancement of an input image by four-wave mixing a first write beam with a second write beam in a photorefractive crystal, e.g., GaAs, achieved for VanderLugt optical correlation with an edge enhanced reference image by optimizing the power ratio of a second write beam to the first write beam, e.g., 70:1, and optimizing the power ratio of a read beam, which carries the reference image to the first write beam, e.g., 100:701. Liquid crystal TV panels are employed as spatial light modulators in order to change the input and reference images in real time.

Abstract: A vehicular external mirror assembly includes a casing having a mirror unit and a tubular member. A first tube has a twisted oblique elongated slot extending longitudinally between a first open top and a first open bottom end of the first tube. The tubular member is slidably sleeved onto the first tube. A threaded rotatable shaft is mounted in the first tube. An elevating unit includes an annular member threadably engaging the rotatable shaft. The annular member has a radial stud projecting through said elongated slot slidably to engage the same and being connected to the tabular member of the casing. An electrical driving unit connected to a lower end of the rotatable shaft includes a motor and a gear assembly interconnecting the lower end of the rotatable shaft and the motor.

Abstract: A mirror unit (11) comprising a mirror holder (12) having a cylindrical support surface (13), and comprising a flexible mirror (14) having a mirror side (15) and a rear side (16); the mirror (14) which has been elastically deformed into a cylindrical mirror rests with its mirror side (15) directly on the support surface (13) of the mirror holder (14) without an intermediate layer, the mirror holder being provided with a shaft (17) which leaves open an optically directly and freely accessible region (19) at the mirror side (15) of the mirror (14) (front surface mirror), this region (19) acting as the functional mirror surface.

Abstract: An objective lens system for use within a microscope includes six lenses which are spaced apart from an object side. The first, the third and the fifth lenses are made of quartz, the fourth and the sixth lenses are made of fluorite, while the second lens is made of either quartz or fluorite. The system transmits ultraviolet and/or far ultraviolet light is simply constructed and corrects chromatic aberration.

Abstract: First and second coherent beams illuminate a common area on an exposure station. A phase detector senses the relative phase between the first and second beams to provide a control signal. There is at least one phase shifter in the path of at least one of the coherent beams. The control signal is coupled to the phase shifter to adjust the phase imparted thereby so that the relative phase between the first and second coherent beams is substantially constant.

Abstract: The apparatus for brightening cockpit instruments contains a passive optical brightening device for directing daylight which shines through front windows of the cockpit, to impinge upon the viewer-oriented cockpit instrument surface.

Abstract: A cold mirror reflector comprising; a reflector substrate; a first high refractive index thin layer disposed upon at least one surface of said reflector substrate which is about one quarter design wavelength in thickness; a relatively thin layer of a highly reflective metal material disposed upon said first high refractive index thin layer; and a second high refractive index thin layer disposed outwardly from said metal thin layer which is about one quarter design wavelength in thickness.

Abstract: The invention relates to a mirror telescope for use in inaccessible assemblies such as in satellites. The primary mirror and the secondary mirror are made of the same material as are all components which fix and influence the distance. In this way, a mirror telescope is provided which maintains its optical characteristics without readjustment over a long period of time.

Abstract: A protective optical device is disclosed. The device includes a transparent shield for protecting a portion of the wearers face and a device for mounting an ophthalmic lens in the transparent shield. The mounting device includes an aperture through the transparent shield, a wall surrounding the aperture and extending forwardly from the shield to a front edge, and a shoulder surrounding the front edge for securing an ophthalmic lens to the front edge. The device allows standard ophthalmic lens to be securely mounted in a protective shield and minimizes the number of lens surfaces of the device.

Abstract: A low cost non-electrical device to afford some protection to computer terminal operators and adjacent persons from the short range rays and electromagnetic fields, as well as providing a comfortable eye level view of the images on the video screen. Also, as an option, a glare shield and/or magnifier can be attached.

Abstract: The use of single crystal MgF.sub.2 material as a window for missile systems has at least the advantages of having superior transmission for both the UV and IR wavelength regions, being stable in sunlight, having a low refractive index, thereby eliminating the necessity for anti-reflection coatings, being unaffected by water, therefore eliminating the need to provide wetness protection, having the mechanical strength to match the applicable usage, being able to be fabricated without excessive complication, thereby reducing manufacturing costs while assuring a high quality product, generating low scatter and being readily available from multiple domestic sources.

Abstract: A method and apparatus for producing temporally coherent, full color holograms is disclosed whereby a linear array of stereographically positioned cameras are simultaneously triggered to obtain a temporally coherent sequence of full color exposures. The exposures are then sequentially exposed upon an H1 plate using multiple wavelength, "white" laser light to obtain a virtual full color hologram image in a single step operation.

Abstract: A grating lens is disclosed in which diffraction efficiency varies in the focusing direction of light on a surface of the lens. Also disclosed is a focusing grating coupler in which the diffraction efficiency of a grating formed on an optical waveguide, which is formed on a substrate, varies in the focusing direction of light.

Abstract: An optical apparatus for simulating a highly interconnected neural network is disclosed as including a spatial light modulator (SLM), an inputting device, a laser, a detecting device, and a page-oriented holographic component. The inputting device applies input signals to the SLM. The holographic component optically interconnects N.sup.2 pixels defined on the spatial light modulator to N.sup.2 pixels defined on a detecting surface of the detecting device. The interconnections are made by N.sup.2 patterns of up to N.sup.2 interconnection weight encoded beams projected by N.sup.2 planar, or essentially two-dimensional, holograms arranged in a spatially localized array within the holographic component. The SLM modulates the encoded beams and directs them onto the detecting surface wherein a parameter of the beams is evaluated at each pixel thereof.

Abstract: A method of manufacturing a display having diffraction grating patterns, includes the steps of (a) obtaining a plurality of two-dimensional images by observing an object at a plurality of positions, and inputting images of the plurality of two-dimensional images in a computer, (b) selecting nth image data from the plurality of image data, (c) inputting data of a reproducing light source position and a view direction, (d) inputting predetermined dot data of the nth image data, (e) determining a pitch and a direction of a grating and an area of a dot on the basis of the data of the reproducing light source position and the view direction and the dot data, (f) moving an X-Y stage to a predetermined position on the basis of the dot data and delineating the diffraction grating by using an electron scanning unit, (g) sequentially incrementing an address of the dot data and repeating the steps (d) to (f) until all data corresponding to the nth image data are processed, and (h) selecting another image data, and repea

Abstract: Object of invention is such an appliance which is suitable for stereoscopic displaying of video images. It is wearable on head having a common stiff frame with two video image displays built in it; then an optical system, containing lenses and mirrors or prisms, is located, arranged symmetrically. Video image diplays (1), e.g. cathode ray tubes, while wearing on head, are located near the temples; in front of the screen (3) there is a mirror or a prism having reflecting surface, having of 45.degree.-75.degree. angles with the plain of the screen on two sides symetrically fitting into optical train between the screen (3) and the concerned pupil, then a lense or lense-system (8), then there is a reflecting mirror (7) having the area not greater than that of the average pupil, in front of the pupils (5), fixing of this mirror (7) is made of transparent material or is covered.

Abstract: A method and an apparatus for locating in the sky celestial objects, using a telescope, wherein two guide stars and the celestial object are represented, according to their respective locations, on a disc which is able to rotate with respect to the telescope around an axis, orthogonal to the telescope axis, and passing through the representation of the celestial objects. The images of the two guide stars are projected in the sky and the telescope and the disc are moved until the images of the guide stars are superposed with the respective actual guide stars in the sky.The guide stars form a triangle with the celestial object. The telescope is preferably provided with a alt-azimuth type mounting. The guide stars are represented on the disc by small holes. A light source placed under the disc creates light dots which are projected in the sky using a plano convex lens optically aligned with the disc rotation axis, and a semi-transparent mirror inclined at 45 degrees on the rotation axis.

Abstract: An optical element for converting a uniform beam of light of wavelength .lambda. into an array of illuminated spots, the optical element including a phase plate made of an array of constant phase zones; and an image plane disposed parallel to and at a preselected distance from the phase plate, the preselected distance being selected so that illuminating the phase plate with uniform coherent illumination of wavelength .lambda. produces the array of illuminated spots on the image plane, the spot array having a fill factor in at least one dimension that is less than 1/2.