Abstract: In an electro-optic line printer of the type having a bit addressable linear modulator for modulating a sheet-like beam of light in response to pixel bits to expose the printer recording medium in line by line fashion. To suppress interference between the beam upper and lower sidebands, the beam is vertically polarized and a halfwave plate, disposed so that the axis thereof is at 45.degree. to the fourier transform plane, is inserted into the path of one of the sidebands to change the polarization of the one sideband from vertical to non-interferring horizontal. In a second embodiment, a halfwave plate is inserted into the path of each sideband, the axes of the plates being such as to form a 45.degree. angle therebetween whereby the sidebands are polarized at an angle of 90.degree. to one another, avoiding interference therebetween.

Abstract: The invention relates to a safety spacer for a bicycle, having an arm one end of which has a reflector and the opposite end of which is fastened to a two-part split member by means of a shaft. The parts of the split member, when assembled, form a shouldered circular circumference. The safety spacer also comprises two fastening lugs which, when pressed together, form therebetween on the one hand a cavity with a shouldered circular circumference for receiving the parts of the split member and for attaching the same and on the other hand a circular aperture for attaching the safety spacer to a tube in a bicycle. The arm can be swiveled and pivoted freely, and all the parts of the safety spacer can be linked together and attached to a bicycle by means of one single screw.

Abstract: Light beam deflecting apparatus comprised of a hologram formed on the peripheral surface of an open-topped hollow cylinder or on a flat disc rotating at a constant rotational speed. A wavefront control device is provided for adjusting the wavefront of the illuminating light proceeding towards the hologram or that of the scanner light diffracted from the hologram in response to electrical signals applied thereto from a control circuit. These electrical signals are changed in association with the scanning of the diffracted beam so as to enable the diffracted light beam to sweep with its focal point running along a straight line on a flat scanning plane.

Abstract: An apparatus for the production of a holographic image of a subject disposed at a subject plane includes a source of coherent light divided by a beamsplitter into a reference beam and a subject beam. The subject beam is directed towards the subject through a beamsplitter and a quarter-wave plate. The front surface of an opaque subject or a mirror behind a transparent subject reflects the subject beam back through the quarter-wave plate to the beamsplitter where it is deflected towards a photo-sensitive recording medium through an imaging lens. The reference beam is simultaneously directed toward the recording medium at a predetermined angle of incidence. After exposure and development of the medium, it is illuminated from the conjugate direction by the redirected reference beam. Image rays exactly retrace their original paths back through the optical system and provide a three-dimensional real-image reconstruction at the subject plane.

Abstract: An optical low-pass filter is comprized of micro stripe prisms arranged on the surface of a transparent member. A transmissive medium which is of different refractive index from that of air is used to fill the grooves of the microprisms to permit the arrangement to have micro stripe prisms with a large vertex angle.

Abstract: A method of and apparatus for minimizing the polarization modulation effect of an optical scanner system which is in earth orbit and is scanning the earth, where the optical train of the scanner includes a plurality of optically aligned, rotatable, flat folding mirrors having incident angle normals in the same plane, with the mirrors serially reflecting an image acquired by the scanning of the system in orbit. The method includes the steps of rotating the most rearwardly disposed of the mirrors around its vertical geometric axis such that the reflecting surface of the mirror is perpendicular to the impinging image beam, and then rotating the mirror around its horizontal geometric axis such that the angle of incidence of the impinging image beam is of a preselected magnitude. This change in positional relationship results in a novel apparatus which minimizes the aforesaid polarization modulation effect.

Abstract: A display arrangement consists of one or more elongate display devices, each of which has a number of separately energizable display areas positioned along its length. When energized, each display area is seen as a bright patch of light. As it is very difficult to arrange that the display areas extend right to the extreme ends of the device, optical deflection means are positioned in front of the display areas to magnify the size of each so that the total display area extends over the whole length of the elongate display device. The optical deflection means is arranged so that each bright patch is of substantially the same size. The invention enables a large number of similar elongate display devices to be placed end to end while avoiding the appearance of periodic dark patches at the ends of adjacent devices.

Abstract: This invention provides a simple and easily manufacturable lens apparatus, a space variant phase shifter, which is one of the key components in an optical ambiguity function generator. The improved lens apparatus is a combination of conventional optics comprising a cylindrical lens and a spherical lens in which the spherical lens is of opposite sign than the cylindrical lens and of one half the power.

Abstract: A high resolution image forming optical system provided with an annular aperture stop arranged near the front side focal plane of a condenser lens and an annular filter arranged in a position conjugate with the annular aperture stop with respect to the optical system including the condenser lens and an objective in order to improve the image-forming performance.

Abstract: A reflector device for use with an optical distance measuring apparatus which includes a frame carrying a reflecting element such as a corner cube type prism and a holder for mounting the frame. The frame has a reference surface and the holder has two or more reference surfaces which are adapted to be alternately engaged with the reference surface on the frame so that the offset value of the prism can be changed.

Abstract: A bicycle spoke reflector assembly is disclosed for use with a bicycle tire assembly. The spoke reflector comprises a structural base member which includes a light reflector thereon. Attaching means includes at least two through members which define spoke channels disposed in relation to the structural member at angles corresponding to the angle defined by at least two spokes, for slidably engaging the structural member. Ornamental display means are provided to removably engaging the structural element for displaying personalized indicia.

Abstract: A hybrid space/time integrating optical ambiguity processor in which time-sequential segments of a spatially modulated optical signal are received in a two-dimensional optical modulator. The output of the optical modulator is periodically imaged along one axis and transformed along a perpendicular axis, and the result is detected for further use. Two embodiments of the two-dimensional optical modulator are described; one utilizing an electrical-to-optical transducer and one utilizing an optical-to-optical transducer.

Abstract: A novel arrangement of variable-focal-length lens using an electrooptic effect is provided. A variable electric field is applied to an electrooptic crystal to produce therein a refractive index distribution having a lens action. The applied electric field is such that the intensity distribution of the lens varies along one direction in a plane normal to the direction of the light incidence but which has a uniform intensity distribution in the direction normal to this direction. A two-dimensional variable-focal-length lens is obtained by combining two such one-dimensional lenses in such manner that the two-lenses intersect each other at right angles with respect to the direction of the lens action. Also, a refractive index distribution having a two-dimensional lens action is produced to form a variable-focal-length lens when an electric field having an intensity distribution which varies within the plane normal to the direction of the incident light is applied to the electrooptic crystal.

Abstract: An emergency signalling device which will transmit a code signal by means of spaced reflective members rotatably mounted upon a member which may be driven by air currents. The device more particularly comprises a rotatably mounted surface such as a hemisphere upon the convex surface of which are provided spaced reflective areas of differing dimensions which will reflect flashes of different duration when exposed to sunlight corresponding to a recognizable code to transmit an emergency message such as S.O.S. Means are provided upon the said surface to permit adjustment of rate of rotation in accordance with the velocity of air currents to which it is exposed.

Abstract: A solid state complementary electrochromic display device in which electrochromic display elements comprising a first electrochromic material layer of a reduction coloration type consisting essentially of tungsten trioxide, a second electrochromic material layer of an oxidation coloration type consisting essentially of iridium oxide or rhodium oxide, and an ion permeable insulating layer disposed between both layers are formed on one surface and on the opposite surface of a transparent substrate.

Abstract: An improved minimum light reflectivity, light transmissive vitreous member and method of fabrication in which an ion implanted, buried ion phase layer is provided within the light transmissive member closely spaced from the light output surface. This buried phase layer has an index of refraction greater than the index of refraction of the vitreous member such that the optical impedance of the buried phase layer and the vitreous material are closely watched to minimize reflectivity from the light output surface of the vitreous member.

Abstract: A retroreflector consists of a support surface 12 coated with a layer 11 of small retroreflecting particles such as glass spheres. The support surface comprises a plurality of regularly repeating, alike, structural elements 13 which are inclined to the overall plane of the retroreflector. The surface elements 13 can be of various shapes and serve to increase the angular range over which retroreflection can occur. The optical characteristics of the proposed retroreflectors can be tailored so that they are eminently suitable for use in certain beam scanning applications such as continuous monitoring of doorways and windows by an optical beam scanning device located at one corner thereof in order to detect, for example, intruders.

Abstract: An apertured rotary member intermittently intercepts a laser beam directed at a given zone of a target. The apertures have inclined lateral walls which, during interception of the beam, deflect at least part of it to a further zone of the target.

Abstract: A heat rays reflecting film composed of dielectric thin layers (n.sub.H layers) having a relatively high refractive index and dielectric thin layers (n.sub.L layers) having a relatively low refractive index which are alternately piled on one another, is disclosed. The first layer of the heat rays reflecting film, which contacts with the air is n.sub.L layer and the undermost layer which contacts with the window glass is n.sub.H layer. The optical thickness of the first layer is less than .lambda./4 while that of the other layers is .lambda./4. And the thickness of each layer is expressed by the formula: optical thickness/nv wherein nv is the refractive index for visible rays.

Abstract: The present invention pertains to a display utilizing a plurality of display prisms in a single device each of which can be separately actuated so that there can be more messages available to a user than surfaces on the prisms due to the interaction of messages on a cooperative basis.