Abstract: A cube corner laser beam retroreflector apparatus for a beam path external to a laser reduces the effect of small deviations in flatness of optical carriage mounting elements and/or linear ways that pitch, yaw and roll the carried retroreflector apparatus. Small changes in pitch, yaw and roll are converted to a small translation in position of the beam reflected from the apparatus. Since the reflected beam remains parallel to the incoming beam, the length of the beam path does not magnify such small deviations in position and system pointing stability is greatly improved. The cube corner retroreflector comprises a welded frame and three mirror holders, the welded frame consisting of plasma, laser or abrasive water jet cut tabbed and slotted flat plates welded together. Each mirror holder is adjustably attached to the welded frame and houses a removable mirror.

Abstract: To provide a triangular-pyramidal cube-corner retroreflective elements extremely superior in reflectivity at an entrance angle of 30° or more, preferably 40° or more. Triangular-pyramidal cube-corner retroreflective elements characterized in that when assuming the height from a bottom plane (Sx-Sx′) including base edges (x,x, . . . ) shared by two triangular-pyramidal reflective elements faced each other up to apexes (H1 and H2) of the triangular-pyramidal reflective elements as hx, the height from a bottom plane (Sy-Sy′) including other base edges (y,y, . . . ) of the triangular-pyramidal reflective elements as hy, and the height from a bottom plane (Sz-Sz) including still other base edges (z,z . . . ) of the triangular-pyramidal reflective elements as hz, any two of hx, hy, and hz are substantially different from each other and a mirror reflective layer is formed on surfaces of the triangular-pyramidal reflective elements.

Abstract: An array of corner reflectors is used to provide a retro-reflector for a large range of incident angles. A novel orientation of the individual corner reflectors is used. This allows the interior of a first corner to remain visible while the interior of a second corner becomes visible. This may be done while maintaining a phase coherence between the contributions of the first and second corner reflectors. Phase coherence ensures constructive interference among the returns from the first and second corner reflectors. Coherence is achieved by an arrangement which places the interior vertices of the corner reflectors close to each other. One such arrangement also places the peak return from one corner reflector acting as a dihedral between the locations of the dihedral and trihedral returns of a second corner reflector. This arrangement results in a substantially uniform and strong retro-return. Phase coherence may be maintained over a desired range of elevation angles.

Abstract: A method and apparatus for making retro-reflective articles are described wherein continuous or large sheets of retro-reflective material can be made without visually disturbing seam lines. In one embodiment molds having retro-reflective elements have serrated edges along boundary lines of retro-reflective elements. In another embodiment the molds are provided with mold lines aligned with edges of the molds and so spaced from the edges that molds can be placed adjacent to one another as part of a grid pattern wherein seam lines are a part of the grid pattern and thus visually hidden. Articles made with molds having mold lines exhibit a regular grid pattern, but without an asymmetric seam line appearing on the article.

Abstract: A retroreflective structure is disclosed that has cube corner retroreflective elements. The structure includes a first array of retroreflective elements oriented in a first direction within a plane and a second array of retroreflective elements oriented in a second direction within the plane, wherein said second direction being about 90° to said first direction. The structure further includes a third array of retroreflective elements oriented in a third direction within the plane, wherein said third direction being about 180° to said first direction and a fourth array of retroreflective elements oriented in a fourth direction being about 270° to said first direction. In one embodiment, the retroreflective structure includes the retroreflective elements having cube corner elements having a pitch between elements in the range of between about 0.0035 and 0.0045 inches (0.088 and 0.114 millimeters).

Abstract: To provide a retroreflective sheeting not only superior in high-brightness characteristic which is a basic optical characteristic generally requested for a triangular-pyramidal reflective element, that is, reflectivity represented by the reflectivity of the light incoming from the front of the triangular-pyramidal reflective element but also whose entrance angularity and rotation angularity are greatly improved.

Abstract: A method and apparatus for making retro-reflective articles are described which can be made without visually disturbing seam lines, In one embodiment molds having retro-reflective elements have serrated edges along boundary lines of retro-reflective elements are used. In another embodiment the molds are provided with mold lines aligned with edges of the molds and so spaced from the edges that molds can be placed adjacent to one another as part of a grid pattern wherein seam lines are a part of the grid pattern and thus visually hidden. In another embodiment, rather than grid lines being introduced into the molds used to form retro-reflective sheets, the grid lines are formed directly on or in the retro-reflective material itself during or after creation. Articles made with molds having mold lines exhibit a regular grid pattern, but without an asymmetric seam line appearing on the article.

Abstract: A see-through retroreflective structure includes a transparent polymeric film, an array of retroreflective elements attached to the polymeric film, and an array of apertures through the retroreflective structure within the array of retroreflective elements. In one embodiment, the retroreflective structure includes a metalized reflective layer formed on the transparent prism elements and a support layer, such as a fabric, is attached to the metalized reflective layer. The method includes providing a transparent polymeric film. An array of retroreflective elements is attached to the polymeric film. The array of retroreflective elements and the transparent polymeric film are perforated through the retroreflective structure to form an array of apertures, thereby forming a retroreflective structure. The apertures are of sufficient size and spacing to provide a see-through capability.

Abstract: A field-of-view controlling arrangement for a display screen or window includes overlay in the form of a single sheet of light transmitting material having a plurality of parallel, spaced apart v-shaped grooves, or a plurality of polyhedral, conical, or frustoconical lens or prism structures, that serve to shift or expand the field-or-view of an image or scene viewed through the sheet. Any of the angled or curved surfaces of the resulting lens or prism structures may be treated to attenuate or scatter light, thereby providing a privacy screening effect with respect to a range of angles determined by the orientation of the treated surfaces.

Abstract: Polyvinyl chloride (“PVC”) compositions and articles are provided which are suitable for fabricating flexible, reflective roll-up roadway signs in which a fluorescent perylene imide dye is present in the PVC reflective layer. The compositions afford enhanced fluorescence durability of perylene imide fluorescent dyes in the articles through the combination of a polymeric hindered amine light stabilizing compound having molecular weight greater about 1500, and a benzophenone ultraviolet absorbing compound. The compositions and articles preferably further comprise a polymeric plasticizer having molecular weight in the range of about 2000 to about 8000 to provide enhanced retention of retroreflectivity in flexible PVC highway signs.

Abstract: An optical element includes first and second members. The first member has a first surface including a first concave portion. The second member has a second surface including a second concave portion and transmits incoming light therethrough. The first and second members are disposed so that the first and second surfaces are opposed to each other. First and second reflective regions have been formed on the first and second concave portions, respectively. At least part of the incoming light that has been transmitted through the second member is reflected from at least one of the first and second reflective regions.

Abstract: A reflective mirror structure comprised of a multiplicity of microprisms whose smallest edge length is less than 2.1 mm, each microprism comprising three mirror facets, a first and second one of the mirror facets as well as a third one and the second mirror facet extending at right angles to each other, while the first and third mirror facets enclose an angle of greater than 90° with each other, and a base facet of the microprisms projected onto a plane forming an irregular hexagon.

Abstract: The apparatus comprises an object for display, a retro-reflector receiving light from the object, a beam-splitter in a path for light from the object to the retro-reflector, and a Fresnel lens (having no point of central symmetry) between the beam-splitter and the retro-reflector. The beam-splitter makes an oblique angle to the direction of propagation of the light, such that it transmits some light and reflects the rest. Light from the beam-splitter passes through the lens to the retro-reflector, which reflects it back through the lens to the beam-splitter. This retro-reflected light is reflected and/or transmitted by the beam-splitter to form a real image suspended in space. The type of Fresnel lens used in the apparatus improves viewability because unwanted reflections from the surfaces of the lens are shifted such that they are no longer visible when viewing the suspended image.

Abstract: A corner cube array device (20) is disclosed having a silicon substrate (30) with a generally cubic crystal lattice. A number of silicon crystal projections (62a, 62b, 62c, 62d, 62e, 62f, 62g) extend from the substrate (30). The projections (62a, 62b, 62c, 62d, 62e, 62f, 62g) each have three generally planar surfaces, as exemplified by surfaces (70, 72, 74) of projection (62a), to provide a cube corner shape. Projections (62a, 62b, 62c, 62d, 62e, 62f, 62g) are spaced apart from each other in accordance with a predetermined spatial pattern to define a cube corner array (60) suitable for optical device applications and the mass production of articles having a substantially similar corner cube array shape.

Abstract: To provide a retroreflective sheet which is suitable for co-molding by injection molding or the like, wherein the retroreflective sheet can be laid within a mold and molded with a resin to form a molded product, and, after molding, the sheet retains a significant portion of its reflection luminance and appearance as compared with the reflection luminance value before molding. A retroreflective sheet used for a co-molding, comprising a metallic reflective layer, a microspherical lens layer disposed as a single layer, and a transparent focal resin layer disposed between the reflective layer and the microspherical lens layer, in which the focal resin layer comprises a mixture of cellulose ester and polyvinyl butyral resin.

Abstract: A retroreflective structure includes a retroreflective sheeting having an array of transparent prisms formed into pairs of prisms. Each prism includes a base aperture and three intersecting lateral faces meeting at an apex. Each of the lateral faces includes a base edge which forms a portion of the perimeter of the base aperture. The base edge of each lateral face intersects the base edge of a contiguous lateral face to form a base point, the first face of at least one prism in the array including a first face first planar surface and a first face second planar surface. The first face first planar surface and the first face second planar surface are contiguous along an edge having a first and second end points, wherein the apex, the first end point, and a first base point are coplanar and form a continuous edge from the first base point to the apex.

Abstract: A retroreflective structure is disclosed that has cube corner retroreflective elements. The structure includes a first array of retroreflective elements oriented in a first direction within a plane and a second array of retroreflective elements oriented in a second direction within the plane, wherein said second direction being about 90° to said first direction. The structure further includes a third array of retroreflective elements oriented in a third direction within the plane, wherein said third direction being about 180° to said first direction and a fourth array of retroreflective elements oriented in a fourth direction being about 270° to said first direction. In one embodiment, the retroreflective structure includes the retroreflective elements having cube corner elements having a pitch between elements in the range of between about 0.0035 and 0.0045 inches (0.088 and 0.114 millimeters).

Abstract: A retroreflective article that exhibits suitable retroreflective luminance under dry and dynamic wet conditions. The article includes an enclosed-lens retroreflective sheeting that, under dry conditions, exhibits a coefficient of retroreflective luminance of about 40 (millicandela/m2)/lux as measured by ASTM D 4061-94 and, under dynamic wet conditions the sheeting increases in coefficient of retroreflective luminance. The article further includes a plurality of retroreflective elements partially embedded in a light transmissible bonding layer on the front, reflective surface of the retroreflective sheeting.

Abstract: A retroreflective article 10 has a body portion 14 and a multitude of cube-corner 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 7×108 pascals. The cube-corner elements 12 contain a light transmissible polymeric material having an elastic modulus greater than 16×108 pascals. A retroreflective article of this construction can be highly flexed while maintaining good retroreflective performance.

Abstract: Laminae suitable for use in a mold suitable for use in forming retroreflective sheeting and methods of making such laminae are disclosed. A representative lamina includes a single row of optically opposing cube corner elements disposed on its working surface. The working surface of a lamina is provided with a plurality of cube corner elements formed by the optical surfaces defined by three groove sets. Corresponding surfaces of opposing groove sets intersect substantially orthogonally along a reference edge to define first and second optical surfaces of the respective cube corner elements. The third optical surface of each respective cube corner element is defined by one surface of the third groove set. The laminae can inclued at least one cube corner element having a four-sided perimeter in plan view in which a first and second pair of opposed paralled sides are obliquely disposed with respect to each other.

Abstract: A cube corner article having a structured surface of geometric structures, each geometric structure having a plurality of faces at least some of which are arranged as a cube corner element, is made by providing a first substrate having a plurality of grooves therein, replicating the first substrate in a second substrate, and forming a second plurality of grooves in the second substrate. Geometric structures in the second substrate are formed in part by replication of the first plurality of grooves and in part by the formation of the second plurality of grooves.

Abstract: A retroreflective structure and method for forming the same are provided which includes a polyurethane sheet having a first side and a second side, a coating on the first side, and an array of retroreflective prism elements formed on the coating. The coating is used to promote adhesion between the prism elements and the first side of the polyurethane sheet. A second coating can be formed on the second side of the polyurethane sheet for purposes such as forming a protective layer over the polyurethane sheet and can include ultraviolet blocking material.

Abstract: An electronic license plate including a housing having a generally rectangular configuration. The housing is mountable to the license plate support of the vehicle and is powered by a vehicle power system. The housing has a front face comprised of a digital display. The digital display displays relevant license plate information of the vehicle. The information relates to a license plate number, a state of issue, and an expiration date. The housing includes a memory chip therein for storing the relevant license plate information thereon. The memory chip is in communication with a main computer system of a selected agency. License plate disabling mechanisms are in communication with the memory chip whereby removal of the housing from the vehicle will disable the memory chip and prevent future use of the electronic license plate. In addition, removal of the license plate disables the vehicle.

Abstract: A triangular-pyramidal cube-corner retroreflective sheeting characterized in that a lateral face (prism face) (face c) using a base edge (x) of triangular-pyramidal reflective elements faced each other and arranged in the closest-packed state by sharing the base edge (x) on a base plane (X-X′) as one side is hexagonal or triangular, two other faces (faces a and b) sharing one ridge line starting with an apex (H) of the triangular-pyramidal reflective elements is quadrangular and when assuming the height from the apex (H) up to the base plane (X-X′) as (h) and the height up to a substantially horizontal plane (Z-Z′) including base edges (z and w) of other two faces (faces a and b) as (h0), and the angle formed between the optical axis of the triangular-pyramidal reflective elements and a plane (Y-Y′) including the base edge (x) and vertical to the base plane (X-X′) as (&thgr;), h and h0 are not substantially equal to each other but h/h0 and &thgr; meet a specific relational expres

Abstract: Laminae suitable for use in molds for forming retroreflective cube corner elements and methods for making such laminae are disclosed. A representative lamina includes a first row of cube corner elements disposed in a first orientation and a second row of optically opposing cube corner elements disposed. The working surface of a lamina is provided with a plurality of cube corner elements formed by the optical surfaces defined by three groove sets. Opposing first and second groove sets are formed in the working surface of a lamina. The first groove set forms a plurality of structures having first and second optical surfaces disposed in mutually perpendicular planes that intersect along a reference edge. The second groove set forms a corresponding plurality of structures on the opposite side of the lamina. A third groove is formed in the working surface of the lamina along an axis substantially perpendicular to the axes of the grooves of the first and second groove sets.

Abstract: A tunable interference add/drop filter system combines an interference filter or the like with a mirror attached adjacent to the filter at an angle under 180° to form a reflector assembly. The reflector assembly is rotated to tune the filter system. The dropped output passes through the filter, while the passed output reflects off of the filter and the mirror. The direction of the passed output beam is a fixed angle from the input beam, and the beam is translated sideways by a fixed amount, no matter how much the reflector assembly is rotated. Thus the dropped output (or complementary output) can be retained. A null state switch prevents light from reaching the filter while the filter system is tuning.

Abstract: A retroreflective article that has a layer of optical elements and a multilayer reflective coating disposed on the optical elements. The reflective coating reflects light back into the optical elements so that it can be returned toward the light source. The multilayer reflective coating has multiple polymer layers and has layers that possess different refractive indices.

Abstract: A retroreflective article 10 has a body portion 14 and a multitude of cube-corner 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 7×108 pascals. The cube-corner elements 12 contain a light transmissible polymeric material having an elastic modulus greater than 16×108 pascals. A retroreflective article of this construction can be highly flexed while maintaining good retroreflective performance.

Abstract: Conformable cube corner retroreflective sheetings comprising a plurality of discrete cube corner segments which are conformably bonded together, each cube corner segment comprising a plastic body portion having a substantially planar front major surface and at least one minute cube corner retroreflective element projecting rearwardly from the body portion and defining a cube corner point side of the cube corner segment. The peripheries of the cube corner segments can be defined by a plurality of separations extending from the cube corner point sides to the front major surfaces, the separations being disposed between adjacent cube corner segments. Adjacent cube corner segments are conformably bonded together in the sense that they are either: (1) separated by a gap of less than about 1 millimeter and bonded together through a conformable carrier layer; or (2) separated by a gap which is substantially filled with a conformable resin that bonds the side walls of adjacent cube corner segments together.

Abstract: Retroreflective sheeting includes a transparent film, a pigmented layer having pigmented indicia thereon, and a retroreflective cube layer. The cube layer includes a number of cube corner elements bounded by at least two sets of intersecting grooves. A metallic film is disposed on at least some of the cube corner elements. The pigmented layer is interposed between the transparent film and the cube layer, and has pigmented indicia aligned with at least one of the sets of intersecting grooves.

Abstract: A reflector is used with an electric distance meter, for measuring a distance of two positions. The reflector includes a reflecting member which reflects an incident light in parallel to the direction of incidence, and a selective transmission member provided to a light-incident surface of the reflecting member. The selective transmission member allows infrared ray to pass, while the selective transmission member prevents visible light from passing.

Abstract: The triangular-pyramidal cube-corner retroreflective sheeting is constituted so that a pair of triangular-pyramidal cube-corner retroreflective elements partitioned by three lateral faces (faces a1, b1, and c1; faces a2, b2, and c2; . . .

Abstract: Laminae suitable for use in molds for forming retroreflective cube corner elements and methods for making such laminae are disclosed. A representative lamina includes a first row of cube corner elements disposed in a first orientation and a second row of optically opposing cube corner elements disposed. The working surface of a lamina is provided with a plurality of cube corner elements formed by the optical surfaces defined by three groove sets. Opposing first and second groove sets are formed in the working surface of a lamina. The first groove set forms a plurality of structures having first and second optical surfaces disposed in mutually perpendicular planes that intersect along a reference edge. The second groove set forms a corresponding plurality of structures on the opposite side of the lamina. A third groove is formed in the working surface of the lamina along an axis substantially perpendicular to the axes of the grooves of the first and second groove sets.

Abstract: Conformable cube corner retroreflective sheetings comprising a plurality of discrete cube corner segments which are conformably bonded together, each cube corner segment comprising a plastic body portion having a substantially planar front major surface and at least one minute cube corner retroreflective element projecting rearwardly from the body portion and defining a cube corner point side of the cube corner segment. The peripheries of the cube corner segments can be defined by a plurality of separations extending from the cube corner point sides to the front major surfaces, the separations being disposed between adjacent cube corner segments. Adjacent cube corner segments are conformably bonded together in the sense that they are either: (1) separated by a gap of less than about 1 millimeter and bonded together through a conformable carrier layer; or (2) separated by a gap which is substantially filled with a conformable resin that bonds the side walls of adjacent cube corner segments together.

Abstract: A fluorescent red article comprising a polymer matrix; and a perylene dicarboximide dye, wherein the article has chromaticity coordinates (x, y) within the area defined by (0.648, 0.351), (0.735, 0.265), (0.629, 0.281) and (0.565, 0.346) in terms of the CIE 1931 Standard Colorimetric System and measured using 0/45 geometry and evaluated with CIE Standard Illuminant D65 and a fluorescence luminance factor of at least about 8, and laminates, retroreflective materials, and methods of making thereof.

Abstract: A method for cutting and edge sealing cells of cellular retroreflective sheeting is disclosed using a specially designed apparatus and tool. Sheeting having a thickness T is heated to a thermoforming temperature to form a heated sheeting. Pressing the unheated tool, the heated sheeting, and a substrate together results in cutting and edge sealing of the heated sheeting. The tool has a radiused ridge for cutting and edge sealing with the shape of the ridge similar to the shape desired for the edge seal. A height H of the ridge is defined relative to the thickness of the sheeting. The fraction of the ridge height to the thickness of the sheeting is less than one and more than 0.2. The tools may be mounted on a perimeter of a wheel for continuously slitting and edge sealing strips of cellular sheeting. The retroreflectivity of the sheeting is maximized by (1) minimizing the width of the sealed edges while (2) maximizing the number of closed cells along the sealed edges that can withstand a water holdout test.

Abstract: The present invention provides a reflective prism device, which comprises a prism unit and a data communication unit, and communication light being irradiated from a survey instrument toward said prism unit, whereby there is provided a light guide for guiding a part of said communication light entering said prism unit toward said data communication unit.

Abstract: A cartridge for a data storage disk drive has a thin retroreflective marker. Light from a source is reflected from the marker almost exactly on its incident path. A planar light shaping optical structure such as a holographic light shaping diffuser (LSD) ruled or blazed diffraction grating, holographic diffraction grating, binary optics or holographic diffraction grating directs light to the detector. The LSD has degrees of angular diffusion in different orthogonal axes. This property makes possible unique identification of different types of cartridges.

Abstract: Retroreflective sheeting includes a body layer having a structured surface with recessed faces and top surfaces, the recessed faces forming cube corner cavities. The recessed faces have a high specular reflectivity, while the top surfaces have a low specular reflectivity. In some embodiments a substantially continuous film of reflective material covers the structured surface, and a masking substance is provided over the reflective material at the top surfaces. Alternatively, the top surfaces are given a non-smooth surface finish so that the film of reflective material on those portions has a diffuse reflectivity. In other embodiments the film of reflective material is discontinuous, disposed selectively on the recessed faces and not on the top surfaces. A cover layer is also provided, and can bond at least to the top surfaces. Keeping the top surfaces substantially free of reflective material inhibits corrosion and can enhance the bond integrity.

Abstract: Retroreflective sheeting includes a body layer having a structured surface with recessed faces forming cube corner cavities. A reflective film is disposed at least on the recessed faces, and a fill material fills the cube corner cavities. The fill material comprises radiation-curable materials, adhesives, or both, and preferably transparent radiation-curable pressure-sensitive adhesives. The fill material preferably forms a continuous layer covering both the recessed faces and upper portions of the structured surface. A transparent cover layer preferably contacts the fill material layer.

Abstract: Retroreflective articles provide varying retroreflection using a first surface that includes a plurality of light redirecting structures and a second surface that includes retroreflective areas and separation areas. The light redirecting structures on the first surface are preferably arranged relative to the retroreflective areas and the separation areas on the second surface such that a substantial portion of light incident on the light redirecting structures is superimposed on areas of the second surface. At some angles, it is preferred that substantially all of the light is superimposed on either the retroreflective areas or the separation areas, resulting in varying retroreflection from the retroreflective articles. Together, the two optical surfaces of the retroreflective articles provide varying retroreflection of incident light where the variations can be between, e.g., retroreflection or no retroreflection, retroreflection of different colors, retroreflection at different brightness levels, etc.

Abstract: A novel microprismatic retroreflective film or sheeting is provided which comprises a transparent semicrystalline polymer. The microprismatic retroreflective film or sheeting of the present invention offers superior retroreflective brightness at large angles of incidence and at large observational angles. Syndiotactic vinyl aromatic polymers, especially syndiotactic polystyrene and copolymers thereof, are preferred semicrystalline polymers, as they impart good dimensional stability and resistance to moisture, and can be made resistant to UV radiation. Signing materials comprising these microprismatic retroreflective films provide improved performance for off-angle illumination and viewing in traffic control and other signing applications.

Abstract: A method is disclosed for manufacturing a plurality of laminae for use in a mold suitable for use in forming retroreflective cube corner articles. Each lamina has opposing first and second major surfaces defining therebetween a first reference plane. Each lamina further includes a working surface connecting the first and second major surfaces. The working surface defines a second reference plane substantially parallel to the working surface and perpendicular to the first reference plane and a third reference plane perpendicular to the first reference plane and the second reference plane. The method includes orienting a plurality of laminae to have their respective first reference planes parallel to each other and disposed at a first angle relative to a fixed reference axis. At least two groove sets are formed in the working surface. Each groove set includes at least two parallel adjacent V-shaped grooves in the working surface of the laminae.

Abstract: Retroreflective prism sheeting is formed in a mold with textured facets and/or windows thereon. Smaller prisms are formed adjacent larger prisms. Optionally, the optical axis of the prisms may be tilted with respect to one another, preferably in a negative direction. The textured facets or windows provide more uniform retroreflected light intensity distribution and whiteness of the sheeting.

Abstract: Laminae suitable for use in molds for forming retroreflective cube corner elements and methods for making such laminae are disclosed. A representative lamina includes a first row of cube corner elements disposed in a first orientation and a second row of optically opposing cube corner elements disposed. The working surface of a lamina is provided with a plurality of cube corner elements formed by the optical surfaces defined by three groove sets. Opposing first and second groove sets are formed in the working surface of a lamina. The first groove set forms a plurality of structures having first and second optical surfaces disposed in mutually perpendicular planes that intersect along a reference edge. The second groove set forms a corresponding plurality of structures on the opposite side of the lamina. A third groove is formed in the working surface of the lamina along an axis substantially perpendicular to the axes of the grooves of the first and second groove sets.

Abstract: Optical reflector for receiving an input beam and transmitting a retro-reflected reciprocal output beam. The optical reflector includes a beam splitter for splitting the input beam into first and second secondary beams. The first and second secondary beams being parallel to one another. A reflecting system is also included for redirecting the first and second secondary beams toward the beam splitter. The reflecting system including a total reflector. The beam splitter and the reflecting system are self-aligned.

Abstract: A retroreflective article that has a layer of optical elements and a multilayer reflective coating disposed on the optical elements. The reflective coating reflects light back into the optical elements so that it can be returned toward the light source. The multilayer reflective coating has multiple polymer layers and has layers that possess different refractive indices.

Abstract: A method for making retroreflective articles that have a layer of optical elements and a multilayer reflective coating disposed on the optical elements. The reflective coating reflects light back into the optical elements so that it can be returned toward the light source. The multilayer reflective coating has at least one polymer layer made by condensing a curing a pre-polymer vapor.

Abstract: Retroreflective sheeting for forming orientation free cones of reflected light encompassing a 0.5 degree angle of observation is formed of small metal backed cube corner prisms in an array in which the size of the prisms are in a range between 0.0005 inch to 0.003 inches on center. The array is formed by casting transparent plastic prisms in a mold formed by ruling three sets of grooves which intersect at an angle. The grooves are spaced apart in the range of 0.0005 inch to 0.003 inches on center. Before or after formation, the prisms are coated with a reflective material such as a metal.

Abstract: This invention provides a method of bonding substantially non-fluorinated polymeric material to a fluoropolymer utilizing a bonding composition comprising primary or secondary di- or poly-amine and a melt-processable, substantantially non-fluorinated component. Multi-layer articles and composite constructions, including retroreflective sheeting and fuel line hoses, made of a fluoropolymer layer and a substantially non-fluorinated layer are also provided.