Abstract: A scan engine is disclosed for use in a data collection device, as well as a method for producing a scan engine and an image sensor assembly. The scan engine includes a housing with an opening for receiving light from a scanned dataform, an image sensor which is located within the housing to sense light entering an aperture in the image sensor, and a prism located within the housing for receiving light from the opening along a first path and to provide at least a portion of the received light to the aperture along a second path.

Abstract: A plurality of microstructures is provided, with each microstructure having at least a first side and at least a second side terminating at a peak. At least some of the peaks can include an elevated portion to space the peaks away from adjacent optical sheets, surfaces, films, substrates, or other layers to minimize wet-out, Newton's rings, abrasions, moire fringes, or other undesirable optical conditions. In other embodiments, an optical film is also provided that includes a first plurality of microstructures having a base, a first side, and a second side, and a second plurality of microstructures having a base, a first side, and a second side, the first side including a first planar surface, and the second side including a second planar surface and a third planar surface.

Abstract: An optical prism 100 for reflecting light incident on its light incidence surface 12 suited for incidence of light from an LCD 20 at least twice within itself and emitting the reflected light as emitted light from a light emission surface 14 to the outside. The optical prism is coupled in use with a display element support 30 adapted to suit it. The side surfaces of the optical prism crossing the light incidence surface 12 and light emission surface 14 have projections 90L and 90R for mounting the optical prism on the display element support.

Abstract: Compact beam manipulators employ one or more Risley prism sets with or without a parallel plate translator. One beam manipulator contains a plate mounted to permit pitch and yaw adjustments and a prism set mounted to permit rotations. The rotations of the prisms adjust a beam direction, and adjustment of the plate adjusts the beam position. Another beam manipulator contains a prism set mounted to permit rotations and pitch and yaw adjustments of the prisms. The rotations and pitch and yaw adjustments provide coupled changes in the position and direction of a beam, and iterative adjustments alternate between rotating prisms to change the beam direction and the adjusting pitch and yaw to change the beam position. The iterative adjustments are complete when the beam has a target position and a target direction to within required tolerances. Gluing elements to optic holders minimizes stress-induced birefringence and temperature and humidity effects.

Abstract: One-dimensional (1D) photonic crystal prisms can separate a beani of polychromatic electromagnetic waves into constituent wavelength components and can utilize unconventional refraction properties for wavelength dispersion over significant portions of an entire photonic band rather than just near the band edges outside the photonic band gaps. Using a 1D photonic crystal simplifies the design and fabrication process and allows the use of larger feature sizes. The prism geometry broadens the useful wavelength range, enables better optical transmission, and exhibits angular dependence on wavelength with reduced non-linearity. The properties of the 1D plhotonic crystal prism can be tuned by varying design parameters such as incidence angle, exit surface angle, and layer widths. The 1D photonic crystal prism can be fabricated in a planar process, and can be used as optical integrated circuit elements.

Abstract: A method for producing a bonded article composed of a first substrate, a second substrate, and a bonding layer through which the first and second substrates are bonded to one another includes the steps of interposing a water-based bonding agent between the first and second substrates, and forming the bonding layer by heating the water-based bonding agent. The water-based bonding agent contains an alkali metal element, and has a water-soluble compound dissolved therein. The water-soluble compound produces a composite oxide by heating.

Abstract: A color image is generated as a composite of images from different image modulators, each modulating a different color, and chromatic aberration of at least one optical element in the associated optical system is compensated by scaling or shifting images from different image modulators differently.

Abstract: An improved roof mirror assembly is provided. The roof mirror assembly of the invention is comprised of first and second mirror panels comprising first and second reflective surfaces and first and second mounting surfaces, respectively, the first and second mirror panels being joined together so that the first and second reflective surfaces are substantially perpendicular to each other. The assembly further comprising at least one mounting block comprising at least one opening extending through a portion thereof and at least one mounting pin received within the at least one opening of the at least one mounting block, wherein the at least one mounting pin is attached within the opening to the at least one mounting block and is attached to at least one of the first or second mounting surfaces of the first or second mirror panels.

Abstract: The invention relates to a beam shaping device for shaping the cross-section of a light beam, comprising at least one beam shaping unit with beam splitting means, beam deflecting means, and beam combination means. The beam splitting means are capable of diving up a light beam that is incident on the beam shaping unit into two partial beams. The beam deflecting means are capable of deflecting at least one of the partial beams onto the beam combination means and said beam combination means are capable of combining the two partial beams in such a manner that the cross-section of the light beam exiting the beam shaping unit is reduced in size in a first direction compared to the cross-section of the light beam that is incident on the beam shaping unit and is increased in size in a second direction perpendicular thereto.

Abstract: Provisions must be made in surgery microscopes for eye surgeries through the selective adding of optics so that a non-reversed and erect-standing image can be produced including that of the fundus of the eye. A device for the image reversion is fastened on the microscope so that it can be moved into the beam path and is then provided between the lens and the eye so that the overall height of the microscope is not influenced. This inventive arrangement can be utilized very universally on very differently designed microscopes and can be operated with prism systems of varying designs.

Abstract: A mounting bracket (40) for suspending a clear aperture of the base face of a prism (30) has a frame providing a horizontal support surface for allowing light to pass through the clear aperture of the suspended prism (30). First, second, and third support elements (44, 46) are spaced apart on the frame for supporting the base face of the prism (30), suspending the clear aperture. The second and third support elements (44) are peripheral to the clear aperture. The center of gravity of the prism (30), vertically projected, lies on or within the triangle formed by the first, second, and third support elements (44, 46).

Abstract: Devices and methods for applying heat to a platen of a biometric image capturing device are described that remove and prevent the formation of excess moisture on the platen. These devices and methods prevent undesirable interruptions of total internal reflection of a prism that result in biometric images having a halo effect. In embodiments of the invention, an electrically conductive transparent material is used to apply heat to the platen. In other embodiments, resistive heating elements attached to non-optical areas of the platen (e.g., the ends) are used to apply heat to the platen. Heater assemblies according to the invention can be used to heat an area where a biometric object is placed, or an area adjacent to where the biometric object is placed, to remove and prevent the formation of excess moisture on the platen.

Abstract: An image projecting apparatus has optical switches in first optical switch unit arranged in a square matrix arrangement, and a second optical switch unit of optical switches in single file for selectively reflecting the monochromatic lights reflected from the first optical switch unit. A light source irradiates a plurality of monochromatic lights of different wavelengths and the monochromatic lights are passed through the optical switches and a square beam generator such that they are incident on a panel unit to realize a monochromatic color stripe of a predetermined size. Light utilization increases through the use of first and second optical switch units, and overlapping between monochromatic color stripes can be prevented through the use of digital micromirror device (DMD) panel or liquid crystal on silicon (LCOS) panel of fast responsiveness.

Abstract: A compact Keplerian optical system includes a telescope having an image-rotator (Pechan roof prism pair), and an eyepiece and objective lens operative to form an intermediate image plane within the image-rotator, thereby decreasing the overall length. The objective lens optionally forms part of a replaceable cap, and plurality of replaceable caps may be provided, each with a different focal length to adjust for working distance. In the preferred embodiments, the eyepiece includes a singlet and a doublet lens to minimize eyestrain, and the objective lens includes a doublet and singlet field lens operative to increase depth of field and field of view. A practical implementation includes a pair of the telescopes, one for each eye of a user. Such a configuration may take the form of loupes mounted relative to eyeglass frames for surgical, medical or dental viewing applications.

Abstract: An optical structure and method for forming same includes a plurality of first cured portions and a plurality of second cured portions that are formed from a same light-curable material. The first plurality of cured portions is cured to a first amount. The plurality of second cured portions is cured to a second amount. The first amount is sufficiently different than the second amount to result with discontinuities on the surface of the structure. The lenticular layer can include a prism layer having random discontinuities on the peaks. The discontinuities can also be formed on a window side of the prisms.

Abstract: The present invention relates to a prism diffuser for diffracting and spreading light, and in particular to a prism diffuser for diffracting and spreading light which is capable of spreading light in a certain direction at a wider angle based on a structure combined with a prism capable of diffracting light on a surface of a medium formed of a glass which transmits or reflect light, a film formed of a transparent synthetic resin material or a metallic plate and a diffuser capable of spreading light and diffracting, spreading and transmitting light into two directions or diffracting, spreading and reflecting light in one direction.

Abstract: A method for fabricating a prism that comprises a first and a second substrate, both translucent, bonded together with an optical thin film interposed at the interface in between and that is used with the interface inclined relative to the optical axis of incident laser light of a wavelength of 420 nm or shorter includes the step of bonding together the first and second substrates of which the difference &Dgr;N1 in refractive index at the wavelength of the laser light fulfills the condition: &Dgr;N1≦|1/(0.3×104×NA×t)|, where t represents the thickness of the first and second substrates cemented together as measured along the optical axis of the laser light, and NA represents the numerical aperture of the incident laser light.

Abstract: First and second half or associated objects, in respective different sequential positions are aligned behind respective adjacent, first and second, inclined faces of an optical prism so that, when viewed at different angles alternately through a front face of the prism, images of the first and second half objects are seen alternately by transmission and total internal reflection at alternate faces, combining to form completed whole images of first and second objects alternatively, thereby providing an impression of animation by object movement. The half objects can be pictures of half of a same or similar face or person having respective different expressions producing a changing expression or hands producing a clapping effect. Written message portions associated with half objects can form a complete message/slogan when viewed at alternate angles. The optical prism can be solid or liquid filled and embodied in picture frames, domestic utensils or personal accessories/apparel.

Abstract: An optical instrument for observation includes, in order from the object side, an objective lens system having positive refractive power, an erecting optical system, and an ocular lens system having positive refractive power. When an anti-vibration mechanism is used to maintain the erecting prism at an orientation in space that is stabilized so as to prevent image degradation due to vibrations of the optical instrument for observation, the erecting prism is constructed to satisfy specified conditions so that ghost light is not generated and so that the optical instrument for observation may be compact.

Abstract: In a vehicle periphery visual confirming apparatus 1A, the vertical angle portion 5 of a prism 4 is chamfered by cutting away the vertical angle adjacent areas 5L, 5R, and light rays 18R (18L) entering the portion of the prism 4, where the vertical angle adjacent areas 5R (5L) was once present, are allowed to pass in front of the chamfered surface 5a and go to the outside through the penetration window portion 2L (2R) of a case, or, are allowed to enter the chamfered surface 5a and are scattered by the rough surface of the chamfered surface 5a, so that the light rays are prevented from advancing into the prism 4.

Abstract: A projection apparatus includes a polarizing converter which converts a light beam from a light source to a polarized beam; a color separator which separates the polarized beam into color beams based on wavelength; first through third optical path modifiers each of which modifies an optical path associated with a corresponding one of the color beams; first through third polarized light separators, each of which receives a corresponding one of the first through third color beams from the optical path modifiers; first through third reflective image display elements, each of which receives a corresponding one of the first through third color beams from the corresponding polarized light separator and provides a reflected beam to the corresponding polarized light separator; a color combiner which combines the reflected beams from the reflective image display elements of the polarized light separator; and a projection lens which projects a color image.

Abstract: An optical system with improved boresight stability having optical elements and a beam expander oriented on a chassis, wherein the beam expander is mounted for minimal movement. By minimizing movement of the beam expander, the angular error of a laser beam travelling through the optical system and subject to various angular tilt errors is reduced by an amount inversely proportional to the magnification ratio of the beam expander based on optical principles. In one embodiment the beam expander is mounted on a highly stiff location on the chassis and away from thermal stresses. Another embodiment is to mount the beam expander to a structural support of a higher assembly. The present invention isolates the beam expander from the instability of individual optical elements and from deformation of the optical bench that impairs the performance and diminishes benefits otherwise gained from the optical principles.

Abstract: Improved methods and systems for routing and aligning beams and optical elements in an optical device include a multiplexing device and/or a demultiplexing device, which includes an optical alignment element (OAE). The OAE can be configured to substantially compensate for the cumulative alignment errors in the beam path. The OAE allows the optical elements in a device, other than the OAE, to be placed and fixed in place without substantially compensating for optical alignment errors. The OAE is inserted into the beam path and adjusted. This greatly increases the ease in the manufacturing of optical devices, especially for devices with numerous optical elements, and lowers the cost of manufacturing. The multiplexing and/or demultiplexing device can reside within a standard small form factor, such as a GBIC. The devices fold the paths of the traversing beams with a geometry which allows a small package.

Abstract: An optical coupler includes a housing, and includes first and second optical terminals and a prism disposed in the housing. One terminal is moveable with respect to the other, and the prism maintains an optical alignment between the terminals. Because it includes a prism instead of a more complex and delicate optical assembly, such an optical coupler can often be less expensive and more rugged, and can often have a higher connection density, than prior optical couplers.

Abstract: The invention relates to a tube for an optical instrument, such as a microscope, having several rotary joints (19, 20, 21) connected serially one behind the other. Each of the rotary joints (19, 20, 21) includes a brake (32, 33, 38) via which the rotary joints are secured against an unintended rotation. The brakes of the rotary joints (19, 20, 21), which are connected serially one behind the other, are simultaneously releasable by actuation of the single operator lever (39). For this purpose, a system of pins (42) and tilt levers (43) is mounted in the tube via which the actuation of the operator element (39) is transmitted to the brakes (32, 33, 38) connected serially one behind the other.

Abstract: The present invention relates to an achromatic phase shift device (1) for introducing a wavelength independent optical phase shift in a first optical beam (40) during operation, comprising at least one dispersive element (55k) formed by first refractive means (2k) and second refractive means (4k), the first refractive means (2k) having a first refractive means input plane (6) for receiving the first optical beam (40) and a first refractive means output plane (8) being at a predetermined angle (&bgr;) to each other, the second refractive means (4k) having a second refractive means input plane (10) and a second refractive means output plane (12) being positioned parallel to the first refractive means input plane (6). The device may comprise further pairs (55k) of respective first and second refractive means (2k, 4k). The present invention also relates to an interferometer comprising at least one achromatic phase shift device.

Abstract: A viewfinder optical system includes an objective lens unit, an image inverting unit for converting an object image formed via the objective lens unit into a non-inverted erecting image, and an eyepiece lens unit for observing the non-inverted erecting image, wherein the image inverting unit comprises a first transparent body and a second transparent body which are disposed with an interval put therebetween, the second transparent body having only a function of transmitting a ray of light, and wherein the interval between the first transparent body and the second transparent body is not uniform.

Abstract: The present invention provides a technique for improving the optical characteristics of a light-selective prism. By cutting a block along a plane perpendicular to a first direction, a plurality of first small blocks are obtained. A first selective film is formed on the cut face of the first small block, and the plurality of first small blocks are stuck together so as to obtain a first processed block in which the first selective film is located at the interface of adjacent two first small blocks. Next, by cutting the first processed block along a plane perpendicular to a second direction that is substantially perpendicular to the first direction, a plurality of second small blocks are obtained. A second selective film is formed on the cut face of the second small block, and the plurality of second small blocks are stuck together to obtain a second processed block in which the second selective film is located at the interface of adjacent two second small blocks.

Abstract: A scan engine is disclosed for use in a data collection device, as well as a method for producing a scan engine and an image sensor assembly. The scan engine includes a housing with an opening for receiving light from a scanned dataform, an image sensor which is located within the housing to sense light entering an aperture in the image sensor, and a prism located within the housing for receiving light from the opening along a first path and to provide at least a portion of the received light to the aperture along a second path.

Abstract: An optical sensor projects light rays emanating from a light emitting element that are collimated by a lens and reflected by a mirror and then directed to a light projecting prism. The collimated light rays incident upon the prism are refracted at an incident surface and come out from the prism through a light exit surface so as thereby to be projected into the field of detection. Light rays passing through the field of detection are directed to a light receiving prism. The light rays incident upon the light receiving prism through a light incident surface are reflected by a light exit surface and then come out from the light receiving prism. The outgoing light rays are received and converted into an electric signal by a light receiving element.

Abstract: An optical film has a transparent film, an adhesive layer provided on one surface of the transparent film, the adhesive layer having a refractive index different by 0.1 or less from that of a layer of the one surface of the transparent film, and a repetitive prismatic structure provided on the other surface of the transparent film, the repetitive prismatic structure having optical path changing slopes aligned in a substantially constant direction at an inclination angle in a range of from 35 to 48 degrees with respect to a plane of the transparent film. Another optical film has a transparent film having an average in-plane retardation of not larger than 30 nm, an adhesive layer provided on one surface of the transparent film, the adhesive layer having a refractive index different by 0.12 or less from that of a layer of the one surface of the transparent film, and the repetitive prismatic structure provided on the other surface of the transparent film.

Abstract: An apparatus for mounting optical components and adjusting its orientation with respect to the optical axis of other components in an optical system. In one embodiment, the multi-axis gimbal mounting apparatus utilizes a single piece main structure having a pair of live hinges and a locking feature that enhances two kinds of stability. First, the adjustable elements of the mount remain in the intended position when the locking mechanism is actuated with minimal cross-talk between the locking features and the adjustment features. Second, the adjustable elements of the mount remain in the intended position when the mount or the system in which it resides is exposed to extreme environmental perturbations of vibration, temperature, shock, and acceleration. This mount is suitable for use in military laser systems, cryogenic systems, and other industrial optical instruments subjected to harsh environments such as aircraft, ship, and battlefield deployed devices.

Abstract: An optical film including a transparent film having a hard coating layer provided on one side thereof, the hard coating layer including a repetitive prismatic structure having formed therein optical-path changing slopes oriented substantially toward certain directions at an angle of 35 to 48 degrees relative to the transparent film, and an adhesive layer laid on the other surface of the transparent film.

Abstract: A light guide plate has a hologram pattern on a light exit surface. The hologram pattern anisotropically diffuses light in the direction parallel with a light incident surface of the light guide plate. On a back surface of the light guide plate are formed mirror-polished prism structures extending parallel with the light incident surface. A downward-pointing prism sheet with a given prism apex angle is placed on the light exit surface of the light guide plate. The use of the downward-pointing prism sheet together with the light guide plate having the anisotropic diffusion hologram pattern integrally formed thereon produces a liquid crystal display device with enhanced luminance properties.

Abstract: An optical film has a transparent film, an adhesive layer provided on one surface of the transparent film, the adhesive layer having a refractive index different by 0.1 or less from that of a layer of the one surface of the transparent film, and a repetitive prismatic structure provided on the other surface of the transparent film, the repetitive prismatic structure having optical path changing slopes aligned in a substantially constant direction at an inclination angle in a range of from 35 to 48 degrees with respect to a plane of the transparent film. Another optical film has a transparent film having an average in-plane retardation of not larger than 30 nm, an adhesive layer provided on one surface of the transparent film, the adhesive layer having a refractive index different by 0.12 or less from that of a layer of the one surface of the transparent film, and the repetitive prismatic structure provided on the other surface of the transparent film.

Abstract: An optical system (20) provides a variable dispersion that helps to collect multi-spectral information on an object within the field of view. The system (20) includes at least two sets (24, 26) of optical elements (42x 42y, 44x, 44y) that have minimal deviation of a center wavelength and a non-zero deviation of at least one other wavelength. By rotating the sets of optical elements (24, 26) relative to one another or together, the degree of wavelength dispersion and the direction of the wavelength dispersion can be varied, respectively. By selectively rotating the sets of optical elements, the system also can be operated in a non-dispersed “white light” mode with no net dispersion at the image plane.

Abstract: An image projection apparatus including a light source for emitting a plurality of monochromatic color beams having different wave lengths; a first light transmit unit; a light switch unit having a plurality of mirrors for selectively deflecting the monochromatic color beams at a predetermined angle; a quadrangular beam generating unit for converting the reflected monochromatic color beams into quadrangular beams having certain ratios of length to height; a panel for receiving the converted quadrangular beams and forming a monochromatic color bar on at least one portion of upper, mid, and lower portions thereof; and a projection lens unit disposed opposite to the panel. Accordingly, by using the light switches, a monochromatic color bar is formed on single panel with the same utilization efficiency of light as that of three panels, thereby embodying a high image quality.

Abstract: A light source with multiple parallel beams is combined with a pair of opposing mirrors mounted on a rotating fixture and with a fixed aperture to produce a single output beam. Through the motion of the rotating fixture, the pair of mirrors shifts the location of the output of each input beam passing through the device so as to sequentially channel each beam into the optical path defined by the aperture. Thus, the input source corresponding to the output beam may be quickly switched by rotating the pair of mirrors to the position that produces the appropriate shift of the beam selected from the light source. In another embodiment of the invention, the pair of opposing mirrors is replaced by a transparent block similarly mounted on a rotating fixture.

Abstract: A projector device is provided which is capable of reducing its costs by making it possible to increase luminance of outgoing light from a rod integrator with an output from a light source being remained unchanged and by making it possible to achieve a compact illuminating optical system using a shortened total length of the rod integrator. Notches each having a predetermined angle or a convex portion is formed in a vicinity of a light incident face and in a vicinity of a light outgoing face of a rod integrator. A sloped line produced at an angle formed by one portion of each of the notches on the light incident side relative to a center line is approximately parallel to a light incident line produced at an angle formed by incident light relative to the center line.

Abstract: Internal drum recording apparatus provided with a rotating deflecting element, comprising two (or more) beams of different wavelengths, which are simultaneously operatable, and optical elements for bringing the two or more beams to a common optical path before they reach the rotating deflecting element. The deflecting element may have dispersing properties such that beams of different wavelengths will leave it at slightly different angles. The beams of different wavelengths may be generated by laser diodes or tunable laser diodes. The apparatus may further comprise a beam combiner to combine the beams generated by the light sources.

Abstract: By mounting a projection lens to a first supporting member for fixing spatial light modulators, polarization beam splitters and a cross dichroic prism, and providing a second supporting member having a thermal expansion coefficient larger than that of the first supporting member between the projection lens and the first supporting member, afluctuation of distance between the spatial light modulators and the projection lens due to heat generated by a light source lamp of a projection type display apparatus and temperature change in use environment can be canceled so that an optimum projected image having nothing to do with being out of focus can always be obtained.

Abstract: The present invention relates to a prism diffuser for diffracting and spreading light, and in particular to a prism diffuser for diffracting and spreading light which is capable of spreading light in a certain direction at a wider angle based on a structure combined with a prism capable of diffracting light on a surface of a medium formed of a glass which transmits or reflect light, a film formed of a transparent synthetic resin material or a metallic plate and a diffuser capable of spreading light and diffracting, spreading and transmitting light into two directions or diffracting, spreading and reflecting light in one direction.

Abstract: The present invention pertains to an optical device useful in a projection system. The optical device can be designed for easy replacement of selected parts, if necessary, without the need for extensive realignment procedures for the projection system.

Abstract: An axicon is disclosed comprising a generally cylindrical body having an exterior surface 31, a first surface 32 and a second surface 35 adjacent opposite ends of the body. A light input beam from a suitable source is directed into one of those surfaces and through the axicon to the other of those surfaces, and the beam is transformed by the axicon into a beam(s) exiting such other surface. The shape and angular extent of the exit beam will depend, in part, on the selected position of the first surface with respect to the optical axis of the axicon and/or the second surface. The axicon is an optical grade unit, preferably unitary, which can receive light of a specified pattern through a first surface, redirect and modify the light, and output light of a different pattern though a second surface. A concentrated light beam can be input to the axicon and output as a differently shaped beam, such as defining a predetermined plane or geometric surface.

Abstract: A resin prism including two or more optical surfaces (11-13) that are not parallel to each other, a pair of side end faces (14, 15) substantially perpendicular to the optical surfaces (11-13), at least one reference block (17) projecting from either one of the pair of side end faces (14, 15) and having a circumferential end face (16) extending in a projecting direction of the reference block, a positioning portion (19, 20) formed on the circumferential end face (16) of the reference block (17), and a curved surface (18) for smoothly connecting the circumferential end face (16) of the reference block (17) and corresponding one of the pair of side end faces (14, 15), wherein the circumferential end face (16) and the corresponding one of the side end faces (14, 15) form an angle of 90° or more.

Abstract: A viewing optical system for display devices or an image pickup optical system, which can be used with high efficiency at a plurality of wavelengths and enables bright images to be viewed with satisfactory color reproducibility and well-corrected aberrations. The optical system comprises a first prism, a second prism and a volume hologram element disposed between them and cemented to them. The hologram element comprises a first volume hologram optimized in such a way as to effect diffraction at least at a first wavelength and a second hologram optimized in such a way as to effect diffraction at a second wavelength different from the first wavelength. The first and second holograms are identical with each other in terms of the shape and spacing of interference fringes on their surfaces but different from each other in terms of the spacing and tilt of interference fringes in their hologram media.

Abstract: The flexible prism is comprised of two thin, rigid, optically transparent plates sandwiching an optically transparent deformable material such as a transparent liquid or a transparent flexible solid. The index of refraction for all of the materials is preferably matched, such that reflections between interfaces are minimized. The liquid/flexible material used in this flexible prism may consist of almost any substantially transparent material that is not rigid like a solid glass. The angles of one or both of the rigid surfaces of the flexible prism can be selectively adjusted with a respect to a spectrally narrow beam of light passing through the prism so as to produce the refraction desired.

Abstract: A light-emitting unit comprises a light emitter made of a semiconductor or a light emitter which is of an electron exciting type. The light-emitting unit further comprises a prism array which is arranged in the vicinity of the front of the light emitter and converts output light rays from the light emitter other than those in a predetermined angle range into light rays in the angle range.

Abstract: An above-the-water system for and method of finding targets, both animate and inanimate, in a marine environment, especially by determining the distance and depth of targets at, above or below the surface of, the water. An optical transmitter transmits infrared and ultraviolet light beams toward different zones of coverage on the water. An optical receiver equipped with a segmented detector separately detects return target reflections. An indicator, including range and depth indicators, provides information as to the distance to the target and, if it is below the water, its depth. A rotating deviation prism increases the target search area.

Abstract: A red-reflecting film and a blue-reflecting film are formed in a substantially X shape on joint surfaces defined by the respective side faces of four columnar prisms or right-angle prisms. The red-reflecting film is continuously formed without separating at an intersection of the two reflecting films. The blue-reflecting film is, on the other hand, divided into two pieces by the red-reflecting film and an adhesive. It is preferable that that four columnar prisms are obtained from one block of sheet glass. This arrangement ensures an improvement in properties of a resulting light-selective prism.