Abstract: Retroreflective articles having cube corner elements are disclosed, with the dihedral angle errors of the cube corner elements selected to limit the visibility range of the retroreflective article. Also disclosed are methods for making the cube corner elements and the retroreflective articles.

Abstract: Both a metallized cube comer retroreflective sheeting having a high measured daytime luminance factor and a method of manufacture thereof are provided. The sheeting is formed from a transparent planar sheet material including on one side a dense array of retroreflective cube comers having height H. The cube comers are canted edge-more-parallel by within about 1.5 degrees of 10n-9 degrees, where n is the index of refraction within the cube comers, and the cube comer faces are metallized by the application of a thin coating of reflective metal. The thickness of the sheet material between the bases of the cube comers and the opposite side of the sheeting is preferably between 1.75 H and 4.00 H. The resulting metallized, retroreflective sheet material may be mounted on a vehicle to increase its nighttime visibility through the ability of the sheet material to efficiently retroreflect a beam of light from a headlight or other source across a broad range of incident and orientation angles.

Abstract: Various embodiments comprise light recycling films comprising an array of parallel ridges and grooves that form prisms that selectively reflect or transmit light. In some embodiments, the light recycling film may be used in displays that include spatial light modulators comprising a plurality of pixels. The light recycling film can limit the field-of-view of the display and enhance the luminance within that field-of-view. Various embodiments comprising multiple arrays of ridges and/or grooves can enhance uniformity of illumination of the pixels in the spatial light modulator and reduce Moiré effects.

Abstract: A cube corner array with minute modifications of the dihedral angles of some of the cube corners is produced by introducing a stress or change via the opposite side of the substrate. The array having aberrated elements can be replicated for use in the manufacture of a tool, and the tool can be used in the manufacture of retroreflective products of broader divergence.

Abstract: A ruling of cube corner elements comprising intersecting ruled vee-grooves is characterized in that at least one of the vee-grooves is made such the substrate being ruled and the cutting tool are oscillated with respect to one another during the ruling of the vee-groove. Rulings made in accordance with the instant invention can be designed to produce a cube corner element having broader divergence.

Abstract: A cube corner array with minute modifications of the dihedral angles of some of the cube corners is produced by introducing a stress or change via the opposite side of the substrate. The array having aberrated elements can be replicated for use in the manufacture of a tool, and the tool can be used in the manufacture of retroreflective products of broader divergence.

Abstract: A method of making an embossed optical sheet material includes: providing an optically anisotropic, uniaxially oriented polymer substrate having a first major surface and a second major surface; heating a patterned tool using radiant energy from a radiant energy source, wherein the pattern comprises a plurality of parallel raised microstructures having a longitudinal direction; pressing the tool against the first major surface of the polymer substrate such that the longitudinal direction of the raised microstructures is substantially parallel to the direction of orientation of the polymer substrate, to soften the first major surface of the polymer substrate and emboss groove-shaped microchannels into the polymer substrate; cooling the embossed polymer substrate; and separating the tool from the polymer substrate; wherein the orientation of the polymer substrate is unchanged throughout the polymer substrate and first major surface.

Abstract: A method of making an embossed optical sheet material includes: providing an optically anisotropic, uniaxially oriented polymer substrate having a first major surface and a second major surface; heating a patterned tool using radiant energy from a radiant energy source, wherein the pattern comprises a plurality of parallel raised microstructures having a longitudinal direction; pressing the tool against the first major surface of the polymer substrate such that the longitudinal direction of the raised microstructures is substantially parallel to the direction of orientation of the polymer substrate, to soften the first major surface of the polymer substrate and emboss groove-shaped microchannels into the polymer substrate; cooling the embossed polymer substrate; and separating the tool from the polymer substrate; wherein the orientation of the polymer substrate is unchanged throughout the polymer substrate and first major surface.

Abstract: Retroreflective articles having cube corner elements are disclosed, with the dihedral angle errors of the cube corner elements selected to limit the visibility range of the retroreflective article. Also disclosed are methods for making the cube corner elements and the retroreflective articles.

Abstract: A method of making an embossed optical sheet material includes: providing an optically anisotropic, uniaxially oriented polymer substrate having a first major surface and a second major surface; heating a patterned tool using radiant energy from a radiant energy source, wherein the pattern comprises a plurality of parallel raised microstructures having a longitudinal direction; pressing the tool against the first major surface of the polymer substrate such that the longitudinal direction of the raised microstructures is substantially parallel to the direction of orientation of the polymer substrate, to soften the first major surface of the polymer substrate and emboss groove-shaped microchannels into the polymer substrate; cooling the embossed polymer substrate; and separating the tool from the polymer substrate; wherein the orientation of the polymer substrate is unchanged throughout the polymer substrate and first major surface.

Abstract: A rulable array of cube corners defined by three sets of parallel, equidistant, symmetrical vee-grooves is provided. The directions of the three vee-groove sets make three angles, no two of which are equal. When the array in viewed in plan, lines along the roots of the grooves determine a pattern of triangles in which the apices of the cube corners lie at distances from their respective triangle's centroid that are substantially less than the distance between the triangle's orthocenter and its centroid. In an unmetallized prismatic retroreflective sheeting, the array of quasi-triangular cube corners has the entrance angularity advantages of compound cant with nearly the efficiency of uncanted triangular cube corners at small entrance angles.

Abstract: A pavement marker having improved daytime visibility comprises a transparent fluorescent top portion having smooth flat parallel top and bottom surfaces with a front edge therebetween and air interfacing most of the bottom surface. Light received by the smooth flat top surface of the top portion is directed internally through the top portion and emitted from the front edge, to provide a visible signal to drivers of oncoming vehicles.