Abstract: A method of increasing retroreflective brightness in a retroreflective sheet material. The retroreflective sheet material has a multitude of prism-like reflective elements imbedded in a transparent polymer plastic top film and glued by a grid of adhesive to a backing sheet. The method includes the step of heating the retroreflective sheet material until bubbles form in the transparent polymer plastic top film containing the prism-like reflective elements. The bubbles are confined by the grid. The bubbles serve as miniature magnifying lenses which increase retroreflective brightness and increase the exposure area thereby providing a wider observation angle.

Abstract: A scale comprising a regular arrangement of optically or magnetically different response characteristics such as light reflection and light diffusion portions or light reflection and absorption portions is attached to a moving object either directly or by way of an intermediate member. The scale can be attached to a motor or the like even after assembling with associated mechanical components, thereby enabling easy measurement of the mode of operation of the motor or similar movable objects. The light beam from the light emitting device is directed to the label media and the reflected light beam is received by a light receiving device to identify the individual object or product based on the label.

Abstract: A retroreflective article 10 has a body portion 14 and a multitude of cube-comer elements 12 that project from a rear side 20 of the body portion 14. The body portion 14 includes a body layer 18 that contains a light-transmissible polymeric material having an elastic modulus less than 7.times.10.sup.8 pascals. The cube-corner elements 12 contain a light transmissible polymeric material having an elastic modulus greater than 16.times.10.sup.8 pascals. A retroreflective article of this construction can be highly flexed while maintaining good retroreflective performance.

Abstract: The invention relates to a glass for at least one signalling lamp, in particular for a motor vehicle. The glass includes a plurality of non-catadioptric elements that have the appearance of catadioptric needles but without performing the same function. At least a portion of the non-catadioptric elements have conical ends on the inside face of the glass. This makes it much easier to make a mold for mass-producing such a glass.

Abstract: A runway marker has a pair of upwardly converging reflectant planar panels facing approximately in opposite directions. In its correct attitude on a support surface the panels slope at 2.degree.-6.degree. to the vertical if the marker is intended for assisting the landing of fixed wing aircraft and at 8.degree.-10.degree. to the vertical if the marker is intended for assisting the landing of helicopters. The reflectant panels are preferably retroreflectant.

Abstract: A photoluminescent retroreflective sheeting for use in structures when a power outage occurs. Guidance systems are made from this sheeting to mark exits and escape routes as well as possible hazards and safety devices. The novel sheeting includes photoluminescent properties that glow in the dark as well as retroreflective properties that retroreflect light incident upon the same sheet such that only one sheet has to be used rather than individual sheets with separate properties.

Abstract: Applicants have discovered that a particularly efficient illuminating device for a transparent display comprises a microtextured reflecting surface formed on a major surface of a transparent substrate and a light source for directing light into the transparent substrate approximately parallel to the major surface. Preferably the substrate has two major surfaces separated by a thickness in the range 0.5 to 1.0 mm so that the substrate acts as a light guide. A substantial portion of the light passing into the substrate undergoes total internal reflection until it hits a microelement and is reflected out of the substrate. The result is an efficient illuminating device particularly useful for lighting transparent displays.

Abstract: The invention is directed to an improved method for making a porcelain enamel tag or sign. The process involves forming a single white porcelain enamel base coat over a suitable metal backing, and firing to bond the porcelain enamel to the metal, resulting in the formation of a porcelain coated metal blank. The blank is then coated with a photographic emulsion which contains a colored frit. The emulsion coating is allowed to dry, and is then ready to receive a printed image. The desired image or graphic to be reproduced is formed on a light transmitting backing, which is made in the form of a print. The print is then affixed to the porcelain enamel blank which contains the emulsion overcoating. The blank containing the image on its surface is then exposed to a source of activating radiation. Following exposure, the image containing blank is developed in a warm aqueous solution, whereby the water serves to develop the emulsion mixture.

Abstract: A remote area landing system combines retro reflective markers with a lighting system. The markers reflect light from a landing aircraft or helicopter. The preferred marker is aluminum with a polycarbonate cover layer. The lights are solar powered and are radio controlled from the aircraft.

Abstract: A pseudo-luminous panel has an optical color filter and a reflecting film formed all over the back thereof. The surface of the optical color filter is formed by obliquely downward and upward band-like surface portions alternately arranged side by side in the vertical direction. The back face of the optical color filter is has obliquely upward band-like back face portions each on the opposite side from one of the obliquely downward band-like surface portions and obliquely downward band-like back face portions each on the opposite side from one of obliquely upward band-like surface portions. The obliquely downward band-like surface portions of the optical color filter are each a smooth surface extending straight in the longitudinal section of the panel. The obliquely upward band-like surface portions of the optical color filter are each a rough surface. The obliquely upward band-like back face portions of the optical color filter are each a smooth surface.

Abstract: A retroreflective article (30, 50) has opaque pigment particles (38, 58) dispersed in a retroreflective region (33, 53) of a front portion (35, 55) of a sheeting (32, 52) that includes a body portion (34, 54) and a multitude of cube-corner elements (36, 56). The opaque pigment particles (38, 58) scatter white, yellow, or light brown light to allow the retroreflective article to demonstrate improved lightness and, if colored fluorescent, improved fluorescence. The improvement in lightness and fluorescence makes the retroreflective articles more conspicuous to persons during the daytime.

Abstract: A flexible retroreflective sheet material is formed by adhering a first face of a first flexible synthetic resin sheet material to a synthetic resin second sheet material by a first adhesive which preferentially adheres to the second sheet material. On the second face of said first sheet material are thereafter formed closely spaced retroreflective microprisms having a height of 0.001-0.010 inches. A second adhesive is applied to the second face of said first sheet and firmly engages therewith. A flexible backing material is adhered to the second adhesive over the second face. Lastly, the second sheet material and first adhesive are stripped from the first sheet material to produce a firmly bonded flexible composite sheet material comprised of the adhesively bonded first sheet material and backing material. The retroreflective microprisms may be coated with a reflective metal deposit or surrounded by air to provide a retroreflective interface.

Abstract: Applicant has discovered a method for microembossing reflector surfaces with controlled reflecting patterns too small to be resolved by the unaided eye but capable of providing controlled reflection characteristics superior to uncontrolled random deformation. The result is a microtextured reflector of having dispersion characteristics of enhanced uniformity and a display device which can be read over an enhanced range of viewing angles. Specifically, a reflector in accordance with the invention comprises a base plane and a pattern of microelements having maximum lateral dimensions less than 125 micrometers and smooth, continuous mold-formed surfaces arising from the base plane. Such a reflector surface can be made using a master formed by covering a substrate with photoresist, exposing the resist to define a pattern of microelements having maximum lateral dimensions less than about 125 micrometers and heating the substrate to partially melt the resist elements thereby obtaining smooth-surfaced microelements.

Abstract: A retroreflective material providing a visual coloration includes a body member with microprisms on its rear surface. Some of the microprisms have a retroreflective interface and the remainder have a colored non-reflective coating thereon. As a result, light rays entering the front face which impinge upon the prisms with the retroreflective interface are redirected so that they exit the material in a parallel path. Light rays which travel to the color coated prisms are refracted from those prisms and impart a visual coloration to the material in daylight and ambient light.

Abstract: Reflective tape for pinstriping of automobiles or other vehicles. The tape has strips of retroreflective material sandwiched between a bottom release liner of polyethylene coated paper and a clear top release liner having an adhesive undersurface for retaining the tape composite intact with the strips parallel one another prior to and during application to a vehicle. The retroreflective material is highly visible at night for safety. The strips include pressure-sensitive adhesive. When the tape is applied to a vehicle, thin pinstripes of retroreflective material are seen. The material may be colored to contrast with the color of the vehicle paint, which is visible on either side of the tape and also through the open middle section between the pinstripes of retroreflective material. The strips are applied by peeling away the bottom liner as the top liner and strips are applied to a surface; thereafter, the top release liner is peeled away leaving only the two retroreflective material strips on the surface.

Abstract: The marker has a pair of upwardly converging reflectant planar panels facing approximately in opposite directions. In its correct attitude on a support surface the panels slope at 2.degree.-6.degree. to the vertical if the marker is intended for assisting the landing of fixed wing aircraft and at 8.degree.-10.degree. to the vertical if the marker is intended for assisting the landing of helicopters. The reflectant panels are preferably retroreflectant.

Abstract: A retroreflective unitary laminate material having an acrylic layer on which a sign legend is printed and which is covered by an ultraviolet absorbent overlay that has poor affinity for paint and low surface tension thus protecting the printed sign from deterioration due to weathering and enabling the sign to be readily cleansed without damaging the printed signs, and minimizing water beading on the sign front face.

Abstract: The invention relates to a method and apparatus for measuring the coordinates of a survey point. The apparatus uses a reflecting mirror at the survey point, a tachymeter for transmitting light to the reflecting mirror and for receiving light reflected from the reflecting mirror, first calculating means for calculating the coordinate values of two positions of the reflecting mirror, and second calculating means for calculating a coordinate value of the survey point from the coordinate values of the two reflecting mirror positions. In operation, the tachymeter transmits light to the reflecting mirror at the survey point wherein the reflecting mirror is locatable at two points present on a line passing through the survey point and which are separated from the survey point by predetermined distances.

Abstract: A retro-reflective target tape comprising a lower sub-laminate having an upper transparent thick mylar backing about 2 mils thick, a release sheet therebeneath and a pressure sensitive adhesive therebetween; and an upper sub-laminate having an upper light reflective sheet with a thin, transparent mylar backing about a half mil thick therebeneath and with a pressure sensitive adhesive therebetween and with pressure sensitive adhesive beneath the thin mylar backing, the upper sub-laminate being cut to form a plurality of circular reflective targets and removed from the lower sub-laminate except for the plurality of circular reflective targets, the pressure sensitive adhesive above the release sheet remaining with the thick mylar backing upon the removal of the adjacent release sheet. Also disclosed is a method of fabricating such tape.

Abstract: Cube-corner type retroreflective articles which retroreflect infrared light but do not substantially retroreflect visible light. The cube-corner elements comprise a polymeric matrix selected to be highly transmissive to infrared light but substantially opaque to visible light.

Abstract: Retroreflective cube corner elements are arranged within layered articles at positions proximate a neutral axis to optimize their performance upon bending or twisting of the article. The elements and surfacs may be embodied in flexible sheeting materials suitable for curving about an object.

Abstract: A telescope baffle system is disclosed for use with optical instruments. The baffle structure consists of highly reflective low scatter annular arrays of retro-reflecting cube corners which have the capability of returning rays back upon themselves such that most off-axis radiation striking one of the baffle annular arrays is reflected back to its source rather than being absorbed or scattered by the baffle.

Abstract: A reflector has 3 planar reflecting surfaces with the upper and lower surfaces each intersecting the central plane at an angle between 145.degree. and 150.degree., each reflecting surface being composed of individually imperceptible cube corner reflectors.

Abstract: A microprism retroreflector material has a body portion with a planar front face and closely spaced microprisms extending thereacross in a plane spaced from and parallel to the front face. The microprisms are formed with three side surfaces disposed along three intersecting planes, and at least some of the microprisms have at least one side surface which is arcuate along one of the intersecting planes and over at least the major portion of its height. At least some adjacent pairs of microprisms have their prism axes tilted relative to the intersecting plane extending therebetween. The microprisms retroreflect light in six circumferentially spaced radially extending exit-energy patterns, and at least 70 percent of the retroreflected light is within a spread of not more than 0.6.degree. from the light rays impinging thereon.

Abstract: The present invention provides an improved cube-corner retroreflective article that exhibits a wide range of retroreflective angularity in multiple viewing planes. The present invention provides cube-corner retroreflective elements having a decreased size, as measured by the height of the cube corner, thereby decreasing the amount of canting required to achieve a given angularity. Alternatively, angularity can be enhanced by leaving the degree of canting constant and decreasing the size of the cube corner.

Abstract: A reflectant surface of retro reflective material comprises a plurality of parallel convex outward ribs having a center-to-center spacing of between 3/8" and 1/16". The retro reflective surface preferably employs an arrangement of triads mutually perpendicular surfaces, which triads and surfaces are indistinguishable at normal minimum viewing distances.

Abstract: Retroreflective elements, such as cube-corner elements or right triangular prisms containing cube-corners, are arranged on articles to define separation surfaces between the elements; in another embodiment, the elements are truncated cube-corners incorporating similar surfaces on the elements themselves. If the surfaces are transparent they will transmit light through the article, rendering it partially transparent and partially retroreflective. The surfaces may be flat or curved. Standard grooving techniques may be employed to construct the elements, using mold cutting tools having flattened or curved tips instead of V-shaped tips; alternatively, electroformed molds may be lapped to include the shape required to produce surfaces. The elements and surfaces may be embodied in sheeting materials or internally illuminated signs.

Abstract: A novel optical device, comprising, in one embodiment, a modified corner cube retroreflector. A conventional corner cube retroreflector may be modified so that a face plate comprises an enhanced reflectivity coating. The novel device functions such that at least five percent of the energy of a radiation beam incident to the device, may be reflected at the face plate in accordance with Snell's Law. It is disclosed that the novel device may be advantageously employed in a novel optical alignment assembly.

Abstract: The present invention provides improved, flexible retroreflective articles based upon an optically clear, aliphatic polyurethane polymer. The aliphatic polymer has a plurality of hard chain segments of the formula--C(O)N(H)--C.sub.6 H.sub.10 --N(H)C(O)--.

Abstract: The signalling baton consists of a cylindrical tube made of unbreakable transparent material and sealingly closed at its ends by a handle and a plug. this tube contains a plurality of reflectors arranged in the form of a prism and retained between the handle and the plug.

Abstract: An optical tape for use decoratively includes a back portion of a first color, a serrated front portion made of a clear plastic. The serrations include alternating wide and narrow grooves such that a side of a wide groove adjoins a side of a narrow groove at an angle of substantially 90.degree.. The sides of each narrow groove have a second color. When the tape is viewed from a distant point, only the first color of the back portion is seen, but when viewed from up-close, substantially only the second color of the narrow grooves is seen.

Abstract: An optical input beam is transmitted through a non-linear medium capable of two-wave mixing gain by photorefractive, Brillouin, Raman, or other non-linear optical mechanism. A psuedo-conjugator retroreflects the input beam which has passed through the medium, back into the medium. The retroreflected beam acts as a seed, which lowers the threshold for producing a self-pumped conjugate reflected beam in the medium by stimulated scattering. The pseudo-conjugator may be a flat array of retroreflecting elements in the form of spheres or corner reflectors. A mosaic pattern of conjugating elements can be phase-locked to yield larger apertures and/or energy scaling, in a master-oscillator, power-amplifier (MOPA), or a four-wave mixer (FWM) configuration. The retroreflected beam can be modulated to temporally encode information onto the conjugate beam, and/or polarized to increase the system efficiency. The input and self-pumped conjugate reflected beams can be used as reference or pump beams in a FWM configuration.