Abstract: An all-around reflector for retroreflection of beams which comprises, as reflectors, triple prisms with round light entrance surfaces, wherein the triple prisms are arranged in a housing in such a way that their light entrance surfaces are part of the circumferential surfaces of the housing. The triple prisms are arranged in the housing in such a way that adjacent triple prisms contact, or almost contact, at a point inside the housing. The tips (corners) of the triple prisms lie in a plane extending vertical to the light entrance surfaces of the triple prisms wherein the axes of the triple prisms which intersect at a point are also located in this plane. Triple prisms which are located next to one another are oriented relative to one another so as to be rotated about their axes by 60°.

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 cube corner article is manufactured by providing a substrate having a surface that includes cube corner elements formed therein, and removing at least a portion of one of the lateral faces on at least one of the cube corner elements, wherein the height of a peak on such cube corner element is reduced. Manufacture of the article can also include forming a replica of the surface of the substrate.

Abstract: A self-contained lighted marking device that is a directionally dependent line light source has a substantially transparent housing. The housing has a narrow cross-section, preferably rectangular in shape. A thin, flexible film having a smooth surface on one side and a plurality of linear substantially right angled isosceles prisms on the other side is located along the periphery of the interior of the housing. A light source, preferably a plurality of light emitting diodes, are located at at least one end of the housing.

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: Retroreflective sheeting and articles are formed in which the size of the retroreflective and non-retroreflective surfaces may be varied across an array of microprisms. This is accomplished by varying the location of the reflective coating applied to the microprism side facets, such that, some prism side facets are completely coated with reflective material while others are coated only at the apex area; and still others are coated with a non-reflective coatings, such as, a colored adhesive.

Abstract: A method of making a retroreflective marking material is provided, the method has the steps of: (a) providing an enclosed-lens retroreflective sheet having a top surface and a bottom surface and comprising a cover layer and a monolayer of retroreflective elements; (b) applying a conformance layer to the bottom surface of the retroreflective sheet; and (c) laminating a configuration member to the conformance layer thereby creating first portions and second portions in the sheet, the first portions being arranged in an upwardly contoured profile and the second portions being arranged in a lower, substantially planar position. A retroreflective article made by the method is also provided.

Abstract: The invention relates to an arrangement for retroreflection of an optical ray using triple prisms. Six to ten triple prisms (1, 2, 3, 131, 132, 133) arm provided with triangular light entry surfaces, wherein the side faces of adjacent triple prisms are in contact. This results in continuous retroreflection at a high level of intensity for one angle area, of 360.degree.. When used in particular in geodesy or in construction surveying, this all-round reflector provides a high degree of measurement accuracy for angles and distances from any direction on which a bearing is taken. Alignment towards a surveying instrument is therefore not necessary. Measurement of short distances is also definite and reliable. The all-round reflector is particularly advantageous for automatic surveying, since, irrespective of its orientation, it can be automatically tracked by a motorised surveying instrument.

Abstract: An article is disclosed having both holographic and retroreflective features. The article includes a holographic layer that is perceptible under normal lighting conditions and substantially imperceptible to the unaided eye under retroreflective lighting conditions, a retroreflective layer perceptible under retroreflective lighting conditions, and means for bonding the two layers together.

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.

Abstract: A retroreflective graphic article bearing a fluorescent legend comprising a retroreflective base sheet, an image layer containing one or more pigments and one or more fluorescent dyes and a dye-receiving layer containing fluorescent dye which migrated from the image layer. Also, a method for making such articles is provided.

Abstract: A method of machining a substrate to produce a cube corner element optical array. The method includes steps of directly machining a plurality of groove sets into a directly machinable substrate to form an array having a plurality of geometric structures including cube corner elements, and machining at least two of the groove sets along the same path in the substrate but at different depths of groove to produce a geometric structure side surface having both an optical portion and a non-optical portion.

Abstract: A multi-layer article comprises a fluoropolymer layer comprising interpolymerized units derived from vinylidene fluoride, and a melt-processable, substantially non-fluorinated polymer layer comprising a polyamide, polyimide, polyurethane, or a carboxyl, anhydride, or imide functionalized polyolefin. The non-fluorinated polymer layer further contains an aliphatic di-, or polyamine which provides increased adhesion between the fluoropolymer layer and the non-fluorinated polymer layer.

Abstract: A retroreflective article (100, 200, 300) that has a retroreflective layer (120, 220, 320) that includes optical elements (121, 221, 321) and a specularly reflective layer (122, 222, 322), and a binder layer (110, 210, 310), that is the reaction product of an epoxy resin and polymer that has a silicon-containing, crosslinkable, terminal, functional groups. Retroreflective articles of this construction can demonstrate good abrasion resistance and laundering durability.

Abstract: Imaging articles and methods are disclosed that use dual-axis retroreflective elements such as 90 degree prisms and linear lenticular elements in which the imaging is either superimposed on the imaged object or displaced therefrom. If the imaging is superimposed on the imaged object, it is accomplished by retroreflection. If the imaging is displaced from the imaged object, it may be accomplished by dual axis retroreflection or retrotransmission.

Abstract: Retroreflective cube-corner articles having randomly oriented cube-corner elements exhibiting rotational symmetry and entrance angularity like microsphere-based sheeting but having increased retroreflective efficiency from cube-corners. The inventive sheeting may contain cube-corner elements typically of different cube-corner geometries, different cube-corner dimensions, and different central axis heights. The cube-corner elements are positioned randomly and are typically not adjacent to one another. Also, methods of making such articles are provided.

Abstract: An imaging element is disposed on a front surface of a retroreflective sheeting to form an image-displaying sheeting. The imaging element includes a light-transmitting prismatic sheeting that has a surface provided with a plurality of parallel prisms. The imaging element also includes an adhesive layer that adheres the prismatic sheeting to the front surface of the retroreflective sheeting. At least a portion of the imaging element is shaped in the form of indicia. In some cases the prismatic sheeting itself is shaped in the form of indicia. In other cases the imaging element includes a light-transmitting colored layer disposed on the front surface of the retroreflective sheeting and shaped in the form of indicia. In the latter case, the prismatic sheeting can be shaped as before to match the indicia-shaped colored layer, or it can extend continuously across the entire retroreflective sheeting.

Abstract: Retroreflective articles provide modulating retroreflection using a front surface that includes at least first and second areas having different transmission characteristics and a back surface that includes retroreflective areas and separation areas. The first and second areas on the front surface are arranged relative to the retroreflective areas and the separation areas on the back surface such that a substantial portion of light incident on the first areas of the front surface at a first angle is transmitted through the first areas of the front surface to the retroreflective areas on the back surface where it is retroreflected back through the front surface. In addition, a substantial portion of light incident on the first areas of the front surface at a second angle is transmitted through the first areas on the front surface to the separation areas.

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.degree. 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.degree. to said first direction and a fourth array of retroreflective elements oriented in a fourth direction being about 270.degree. 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 reflective article has a multilayer film covering a patterned retroreflective layer. In one embodiment the patterned retroreflective layer includes a separate indicia layer covering a retroreflective substrate. The indicia are substantially hidden under normal viewing conditions but easily detectable under retroreflective lighting conditions. Various types of retroreflective layers are disclosed. The article can also include microstructured relief patterns which produce holographic images under ambient lighting but which disappear under retroreflective conditions. The multilayer film includes alternating layers of at least a first and second polymer, and has a relatively high reflectivity for normally incident light within a first spectral range which is approximately coextensive with the visible spectrum, and a relatively low reflectance for normally incident light within a second spectral range.

Abstract: This small, inexpensive, non-contact laser sensor can detect the location of a retroreflective target in a relatively large volume and up to six degrees of position. The tracker's laser beam is formed into a plane of light which is swept across the space of interest. When the beam illuminates the retroreflector, some of the light returns to the tracker. The intensity, angle, and time of the return beam is measured to calculate the three dimensional location of the target. With three retroreflectors on the target, the locations of three points on the target are measured, enabling the calculation of all six degrees of target position. Until now, devices for three-dimensional tracking of objects in a large volume have been heavy, large, and very expensive. Because of the simplicity and unique characteristics of this tracker, it is capable of three-dimensional tracking of one to several objects in a large volume, yet it is compact, light-weight, and relatively inexpensive.

Abstract: A method for tooling a pattern of retroreflective microcubes, which pattern can be subdivided into smaller increments within which there are straight line tooling paths, none of which pass through an otherwise solid part of the incremental pattern. The tooling paths within the various increments need not be parallel to a common plane. Various adaptions of the method enable the tooling of a number of specific microcube shapes and for modifying such optical properties of the microcubes as entrance angularity, incidence angularity, orientation angularity, observation angularity, percent active aperture and retroreflectance. Specific techniques govern the pre-selection of cube parameters such as cube axis cant, cube apex decentration, and cube boundary proportions, which parameters can be adjusted independently of each other. Designs tooled by the method can have 100% active aperture at near zero degrees entrance angle.

Abstract: A retroreflective sheet comprises a film having a substantially flat surface and a large number of pyramidal projections having retroreflectivity on the opposite surface, and a colored layer and an adhesive layer disposed on the surface of the film having the projections. The adhesive layer comprises a heat-sensitive adhesive containing an acrylic polymer and a phenolic resin, and exhibits an elastic modulus (by dynamic viscoelasticity measurement, compression mode) at 30.degree. C. ranging from about 1.times.10.sup.6 to 1.times.10.sup.8 dyn/cm.sup.2.

Abstract: The invention relates to a sensor system based on the retroreflection of a laser beam comprising a retroreflection surface having a series of microtriplet reflectors. The sensor system has individual micro reflector elements that are formed by the three adjacent square surfaces of a cube corner. The individual micro reflector elements have a cross sectional area similar to an equilateral hexagon having a width over flats of 0.002 to 1.4 mm. With this design, the laser beam simultaneously contacts at least five microtriplets on the surface of the retroreflector.

Abstract: Microstructured articles of the invention comprising, in order: a) a retroreflective microstructured member; b) a sealing layer melt-bonded to the microstructured member; and c) a backing member. The backing member is a fibrous web comprising a plurality of multifilament strands and is melt-bonded to the second surface of the sealing layer.

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.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: Radiation curable ink compositions and coating compositions contain an aliphatic (meth)acrylate functional macromonomer, a reactive acrylate monomer, and a photoinitiator. Ink compositions also contain an effective amount of a colorant or pigment. These inks, when cured by exposure to actinic radiation, have excellent durability, weatherability, and adhesion to acrylate substrates such as polymethylmethacrylate.

Abstract: A reflective plate (10) is disclosed, comprising a substrate (1), a retroreflective sheet (2) adhered to the surface of said substrate and having substantially flat base portions (3) covered with said retroreflective sheet (2), the retroreflective sheeting having retroreflective elements and a light transmissive cover layer; and a plurality of projections (4) covered with said retroreflective sheet and present on the corners of regular polygons that are arranged to form a regularly repeated pattern, wherein the arrangement of the projections (4) satisfies the relationship 0.05<h/P<0.60.

Abstract: A process and article for a retroreflective polymeric coated flexible fabric material having a retroreflective layer and a polymeric compatibilizing layer welded to a polymeric coated outer surface of a flexible fabric material. The compatibilizing layer provides an intermediate layer between the retroreflective layer and the flexible fabric material creating suitable bond strength between dissimilar polymers.

Abstract: A cube corner article and method of manufacturing the article from a series of directly machinable unitary substrates. The method of manufacture comprises the first step of providing an initial unitary directly machinable substrate of material suitable for forming retroreflective surfaces. Then, a first cube corner element array zone is formed having a plurality of geometric structures including cube corner elements. The zone is created by directly machining at least two sets of parallel grooves in the substrate. A replica of the cube corner element array zone is formed as an additional unitary substrate suitable for forming retroreflective surfaces. Portions of the replica substrate material are removed. The removal of these portions forms at least two intersecting cavities bounded by side walls in the replica at a depth at least that of the cube corner elements formed by the groove sets.

Abstract: The invention relates to a retroreflector or a retroreflector arrangement in which the faces of the retroreflector are directly heated by a heating element. The retroreflector comprises a triple-mirror prism having three isosceles limiting faces and one equilateral limiting face. Also, the retroreflector has at least one heating element in direct contact with each of the faces. The heating elements directly heat the faces. As a result, the effectiveness of the retroreflector is not diminished in extreme weather conditions, for instance, in extremely cold or humid conditions.

Abstract: A cube corner article and method of manufacturing the article from a series of directly machinable unitary substrates. The method of manufacture comprises the first step of providing an initial unitary directly machinable substrate of material suitable for forming retroreflective surfaces. Then, a first cube corner element array zone is formed having a plurality of geometric structures including cube corner elements. The zone is created by directly machining at least two sets of parallel grooves in the substrate. A replica of the cube corner element array zone is formed as an additional unitary substrate suitable for forming retroreflective surfaces. Portions of the replica substrate material are removed. The removal of these portions forms at least two intersecting cavities bounded by side walls in the replica at a depth at least that of the cube corner elements formed by the groove sets.

Abstract: A retroreflecting polarizer comprises a pair of first and second substrates, each essentially like the other, each having a planar first surface and a structured second surface, whereby the structured second surface comprises a linear array of isosceles prisms with faces formed at an angle of approximately tan.sup.-1 (1/n) with respect to the planar first surface. The respective structured second surfaces of the first and second substrates are mated with one another through one or more of substantially uniformly thick layers, all of the same optical material, that are parallel to the structured surfaces. The structured surfaces and layers are separated from one another by associated air gaps. The interfaces formed within the retroreflecting polarizer satisfy Brewster's condition for a light beam normally incident upon the retroreflecting polarizer which is split into a .sigma.-polarized retroreflected light beam and a substantially .pi.-polarized transmitted light beam.

Abstract: A reflective article has a structured surface which includes geometric structures each having at least three specularly reflecting faces which converge at an apex or other extremity. The article is marked with a plurality of spots located between the extremities, the spots having different reflectivity characteristics than the specularly reflecting faces. The geometric structures can comprise cube corner elements. The spots can be diffusely reflecting and distributed uniformly on the structured surface or distributed to define a particular pattern. The article can have a plurality of first active areas at a first illumination geometry, and the spots can be sized and positioned such that they avoid the first active areas. The article can have first inactive areas adjacent the first active areas, and each spot can cover a majority of one inactive area.

Abstract: A cube corner retroreflective sheeting construction comprising alternating zones of cube corner element arrays disposed at approximately ninety degrees orientations to provide exactly two principal plane of improved retroreflective performance in response to light incident on the sheeting at high entrance angles is disclosed. According to one embodiment the sheeting includes a body layer which has an elastic modulus less than 7.times.10.sup.8 pascals and cube corner elements formed from a material which has an elastic modulus greater than 16.times.10.sup.8 pascals. According to a second embodiment the sheeting includes an overlay film having two major surfaces and comprising a first polymeric material and a plurality of arrays of substantially independent cube corner elements bonded to a major surface of the overlay film having a minimal, fractured land.

Abstract: A reflecting sheet which comprises a transparent sheet capable of reflection by its reverse, said transparent sheet having the face which is partly or entirely constructed of a plurality of composite surfaces, each being a combination of a cylindrical surface inclined in one direction only and a curved or flat surface inclined in the opposite direction, said composite surfaces being contiguous or intermittent with a flat surface interposed between and being constructed such that a large part of their surface area is accounted for by the cylindrical surfaces, and also having the reverse which is constructed of a plurality of contiguous corner-cube prisms.

Abstract: Cellular retroreflective sheeting comprises a first film of thermoplastic material which has been formed to define arrays of minute cube-corner reflective elements on one face thereof. The reflective elements are covered with a second thin thermoplastic film and the two films together pass over a patterned roller where a series of sonic welding heads rapidly bond the films together forming small cells of retroreflective cube-corner elements in the pattern of the roller. Because the heat generated in the welding process is localized to the pattern of the roller, cell walls may be formed having narrow thickness yet good bonding of the films is achieved. Further, residual heat does not appreciably transfer to adjacent retroreflective elements, therefore, distortion of adjacent elements is minimized and a sheeting construction is achieved having superior brilliance and durability as well as maximum retroreflective capability over a wide angular range of incident light.

Abstract: The present invention provides improved cube corner retroreflective articles which exhibit a wide range of retroreflective entrance angularity in at least one plane, and preferably in two or more planes. An article in accordance with the present invention includes a structured surface having at least one array of cube corner elements formed by three intersecting sets of substantially parallel grooves. Each cube corner element includes a base triangle bonded by one groove from each of the three intersecting groove sets, the base triangle being scalene.

Abstract: A one-way see-through panel assembly enhanced by a retroreflective surface. The panel assembly has a first panel which has a dark light-absorbing surface and an opposite light reflecting surface. A retroreflective sheet is applied over the light reflecting surface to form an assembly. Light passageways, either perforations or a pattern of discrete transparent areas, are provided in the assembly. An image is imprinted on either the surface of the retroreflective panel or the light reflecting surface. The method includes mechanically perforating the assembly which is facilitated by the retroreflective sheet having non-glass reflective formations thereon.

Abstract: A fluorescent yellow article containing a blend of an N,N'-disubstituted 3,4:9,10-perylenebis(dicarboximide) dye and a fluorescent yellow-green dye soluble in a polymeric matrix and meeting the chromaticity requirements of CIE and ASTM and having a fluorescence luminance factor of greater than 5, as well as a method of preparing such articles is described. Also described is a fluorescent retroreflective article containing a color layer having first and second sides, wherein the article includes retroreflective elements on one side of the color layer or a retroreflective base sheet disposed on one side of the color layer, where the color layer includes the above-mentioned fluorescent yellow article.

Abstract: A retroreflective cube corner article which is a replica of a directly machined substrate comprises a plurality of single cube corner elements which are machined in the substrate. Each cube corner element is bounded by at least one groove from each of three sets of parallel grooves in the substrate so that the article comprises a plurality of different geometric structures.

Abstract: A cube corner article and method of manufacturing the article from a series of directly machinable unitary substrates. The method of manufacture comprises the first step of providing an initial unitary directly machinable substrate of material suitable for forming retroreflective surfaces. Then, a first cube corner element array zone is formed having a plurality of geometric structures including cube corner elements. The zone is created by directly machining at least two sets of parallel grooves in the substrate. A replica of the cube corner element array zone is formed as an additional unitary substrate suitable for forming retroreflective surfaces. Portions of the replica substrate material are removed. The removal of these portions forms at least two intersecting cavities bounded by side walls in the replica at a depth at least that of the cube corner elements formed by the groove sets.

Abstract: An optical film having high light transmittance and excellent light diffusibility is provided. The optical film comprises a transparent substrate 1 and a light diffusion layer 2 formed on one or both sides of the substrate 1. As the resin 3 of the light diffusion layer 2, an ionizing radiation curable resin is used in an amount of, preferably, not less than 50% of the resin and a small amount of the light diffusive agent is dispersed therein. The optical film exhibits excellent light diffusion effect even though the content of the light diffusive agent is small and also exhibits high light transmittance because of the small content of the light diffusive agent. Accordingly, this optical film is suitable for applications such as a color liquid crystal display which is required to have a sufficient brightness, and in combination with another optical material such as a prism lens.

Abstract: A retroreflective sheeting includes a first array of cube corner element opposing pairs and a second array of cube corner element opposing pairs. The symmetry axes of the cube corner elements in the first and second arrays are tilted in a backward direction at an angle of about 12.degree. to about 30.degree. from an axis normal to a base surface. The second array of cube corner elements is oriented approximately perpendicular to the first array to yield a retroreflective article providing generally uniform total light return about a 360.degree. range of orientation angles and/or a minimum total light return of about 5% across such 360.degree. range. Also disclosed is a mold assembly suitable for use in forming the present retroreflective sheeting and a method of making a retroreflective article using the mold.

Abstract: A fire-resistant retroreflective structure having an array of rigid retroreflective elements and a method for making the structure are disclosed. The retroreflective structure is formed of an array of rigid retroreflective elements having a first side and a second side. A transparent polymeric film is attached to the first side of the array of rigid retroreflective elements. A transparent fire-resistant outerlayer is attached to the transparent polymeric film. A flame-retardant layer is placed proximate to the second side of the array of rigid retroreflective elements. A fire-resistant polymer underlayer is attached to the flame-retardant layer. The five resistant polymer underlayer can be bonded to the transparent polymeric film through the array of rigid retroreflective elements and the flame-retardant layer.

Abstract: Dual axis retroreflective articles and methods of using them are disclosed. The retroreflective articles may combine dual axis retroreflection with three axis retroreflection to provide a steady glow due to the three axis retroreflective portions of the article and also provide intermittent or flashing retroreflection as the plane of retroreflection from the dual axis retroreflector passes through or near the light source. The retroreflective articles may also include dual axis retroreflective structures in combination with sparkling reflective structures, as well as dual axis retroreflective structures in combination with both three axis retroreflective structures and sparkling reflective structures. Methods of use include moving the dual axis retroreflective structures to obtain intermittent or flashing retroreflection.

Abstract: The present invention provides a retroreflective sheeting including: optical elements arranged in substantially a monolayer; a spacing layer in which the optical elements are at least partially embedded; a specularly reflecting layer underlying the spacing layer; and a bead bond layer in which the optical elements are at least partially embedded. The bead bond layer includes an aminoplast-crosslinked polymer comprising urethane groups, wherein prior to crosslinking the polymer has a glass transition temperature (Tg) of less than about 0.degree. C.

Abstract: Retroreflective article that provides effective retroreflective brightness at very high entrance angles as well as low entrance angles.

Abstract: An article is disclosed having both holographic and retroreflective features. The article includes a holographic layer that is perceptible under normal lighting conditions and substantially imperceptible to the unaided eye under retroreflective lighting conditions, a retroreflective layer perceptible under retroreflective lighting conditions, and means for bonding the two layers together.

Abstract: A measuring apparatus for determining the location of a point in space using a coordinate measuring machine, such as a laser tracker. The apparatus comprises a retroreflector releasably coupled to a sphere of a tooling ball. The tooling ball is rigidly coupled to a mechanism whose position is to be found and whose movements can be monitored by repeatedly determining the position of the center point of the sphere of the tooling ball. The retroreflector is formed of solid glass and has a corner cube having a vertex which has a predetermined dimensional relationship with and represents the virtual location of the point in space, that is, the center point of the sphere. The retroreflector is configured to receive a beam of light from the laser tracker and then reflect and retroreflect the beam to the laser tracker to determine the location of the vertex of the corner cube and, thus, the center of the tooling ball.