# US RE40,455 E1 · Retroreflective articles having microcubes, and tools and methods for forming microcubes > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US RE40,455 E1 - Document ID: USRE40455E1 - Status: Granted - Kind: E1 - Application number: 11/515,509 - Filed: 2006-08-31 - Granted: 2008-08-12 - Earliest claimed: 1996-05-30 - Assignees: Avery Dennison Corporation - Inventors: Sidney A. Heenan; Liviu A. Coman; Dennis I. Couzin - Web page: https://patentgrep.com/patent/USRE40455E1 ## 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. The method involves providing a plurality of plates of micro thickness, each plate having at least one end comprised of a material that can be tooled with polished surfaces by means of an appropriate tool, tooling on said end of each plate an increment of the pattern, and assembling the plates together in various ways to form a master. Retroreflective articles made by means of this technique are expected to provide superior performance when used in pavement markers, highway signs and other applications. ## Claims ### Claim 1 An article comprising an array of microcubes, at least one of said microcubes being non-hexagonal, such that for every plane in space there are two adjacent microcubes for which at the place of the adjacency none of the face edges is parallel to that plane, said at least one microcube having a projected area of less than 1 mm2, said at least one microcube being canted edge-more-parallel. ### Claim 2 (depends on 1) The article of claim 1 wherein said array is retroreflective. ### Claim 3 (depends on 2) The article of claim 2 wherein said article comprises retroreflective sheeting. ### Claim 4 (depends on 3) The article of claim 3 wherein at least one microcube of said array has a projected area of about 1 mm2 or less. ### Claim 5 (depends on 4) The article of claim 4 wherein at least one microcube of said array has a projected area of about 0.35 mm2 or less. ### Claim 6 (depends on 5) The article of claim 5 wherein at least one microcube of said array has a projected area of about 0.04-0.12 mm2. ### Claim 7 (depends on 3) The article of claim 3 wherein said sheeting comprises a polymer resin. ### Claim 8 (depends on 7) The article of claim 7 wherein said polymer resin is selected from the group consisting of acrylic, polycarbonate, vinyl, polyester, and polyethylene. ### Claim 9 (depends on 7) The article of claim 7 wherein said microcubes are formed by embossing. ### Claim 10 (depends on 7) The article of claim 7 wherein said microcubes are formed by casting. ### Claim 11 (depends on 3) The article of claim 3 wherein said sheeting is transilluminated. ### Claim 12 (depends on 1) The article of claim 1 in which at least one microcube of said array is canted. ### Claim 13 (depends on 12) The article of claim 12 in which at least one microcube in said array is edge-more-parallel. ### Claim 14 (depends on 13) The article of claim 13 wherein retroreflectance in the plane of symmetry of the microcubes of said array is substantially constant and is greater than about 50% for all entrance angles less than about 30°. ### Claim 15 (depends on 12) The article of claim 12 in which not all the cube axes in said array are parallel to each other. ### Claim 16 (depends on 15) The article of claim 15 in which some adjacent cubes are alternately face-more-parallel and edge-more-parallel. ### Claim 17 (depends on 12) The article of claim 12 in which said array is a retroreflective part of a pavement marker. ### Claim 18 (depends on 1) The article of claim 1 wherein said article is a master for use in the production of a tool for making a retroreflective article. ### Claim 19 (depends on 1) The article of claim 1 wherein said article is an electroform for use in the production of a tool for making a retroreflective article. ### Claim 20 (depends on 1) The article of claim 1 wherein said microcubes of said array are of unequal sizes. ### Claim 21 An article comprising an array of microcubes, at least one of said microcubes being non-hexagonal such that for every plane in space there are two adjacent microcubes for which at the place of the adjacency none of the face edges is parallel to that plane, said at least one microcube having a projected area of less than 1 mm2, in which array at least one said microcubes is canted, said array being formed of a material having a refractive index n, and the cant of at least one microcube in said array does not exceed about tan−1√{square root over (2)}−sin−1(1/n). ### Claim 22 An article comprising an array of rectangular microcubes, at least some of which have no dihedral face-edges collinear with any dihedral faces-edges of any adjacent microcubes, at least one of said rectangular microcubes having a projected area of less than 1 mm2, said at least one microcube being canted edge-more-parallel. ### Claim 23 (depends on 22) A pavement marker for establishing on a finished roadway surface a marking visible from an oncoming vehicle, said pavement marker comprising a base member adapted to be mounted on the finished roadway surface, and a retroreflective signal means, said retroreflective signal means comprising an array of microcubes of claim 22. ### Claim 24 (depends on 23) The pavement marker of claim 23 wherein the retroreflective signal means front surface is sloped about 30°-40° with respect to the road surface and comprises an array of canted rectangular microcubes, the cube axis cant being in the range of about −5° to −13°. ### Claim 25 (depends on 24) The pavement marker of claim 24 having horizontal entrance angularity up to at least about 30°. ### Claim 26 An article comprising an array of microcubes in which every region of three by three microcubes is nonrulable and in which at least one microcube in a said region of three by three microcubes is rectangular, said at least microcube having a projected area of less than 1 mm2, said at least one microcube being canted edge-more-parallel. ### Claim 27 An article comprising an array of microcubes, at least one of said microcubes being rectangular such that for every plane in space there are two adjacent microcubes for which at the place of the adjacency none of the face edges is parallel to that plane, said at least one microcube having a projected area of less than 1 mm2, in which array at least one of said microcubes is canted, said array being formed of a material having a refractive index n, and the cant of at least one microcube in said array does not exceed about tan−1 √{square root over (2)}−sin−1 (1/n). ### Claim 28 (depends on 27) The article of claim 27 in which a plurality of microcubes in said array are male microcubes and said array of microcubes is nonrulable. ### Claim 29 (depends on 27) The article of claim 27 in which a plurality of said microcubes of said array have a projected area of about 0.35 mm2 or less. ### Claim 30 (depends on 27) The article of claim 27 in which a plurality of said microcubes of said array have a projected area of 0.12 mm2 or less. ### Claim 31 (depends on 27) The article of claim 27 in which the article comprises retroreflective sheeting. ### Claim 32 (depends on 27) The article of claim 27 in which one or more microcubes within said array have substantially 100% active aperture for incidence angles of about zero degrees. ### Claim 33 (depends on 27) The article of claim 27 in which said array comprises at least three consecutive rows of said microcubes. ### Claim 34 (depends on 27) The article of claim 27 in which said array of microcubes comprises rows of said microcubes in which each row of microcubes is a replica of a structure that has been ruled on the end of a microthick plate. ### Claim 35 (depends on 27) The article of claim 27 in which said array comprises rows of rectangular microcubes, in which each row is a replica of a structure that has been ruled on the end of a microthick plate by a bevel face formed along the end of the plate and a plurality of v-grooves substantially perpendicular to the bevel face. ### Claim 36 (depends on 35) The article of claim 35 in which adjacent rows of said microcubes correspond to adjacent plates oriented 180° to each other. ### Claim 37 (depends on 35) The article of claim 35 in which said array comprises microcubes present as opposed paired microcubes, and in which said array comprises pairs of rows of rectangular microcubes in which each pair of rows is a replica of a structure that has been ruled on the end of a microthick plate by a v-groove extending along the center of the plate end, with opposed pairs of v-grooves extending substantially perpendicular to the center v-groove. ### Claim 38 (depends on 27) The article of claim 27 in which said array comprises an array of male microcubes for which every three by three subarray of said microcubes is nonrulable. ### Claim 39 (depends on 38) The article of claim 38 in which the article comprises retroreflective sheeting. ### Claim 40 (depends on 39) The article of claim 39 in which one or more microcubes within said array have substantially 100% active aperture for incidence angles of about zero degrees. ### Claim 41 (depends on 40) The article of claim 40 in which a plurality of said microcubes of said array have a projected area of about 0.35 mm2 or less. ### Claim 42 (depends on 40) The article of claim 40 in which a plurality of said microcubes of said array have a projected area of 0.12 mm2 or less. ### Claim 43 (depends on 38) The article of claim 38 in which said array comprises at least three consecutive rows of said microcubes. ### Claim 44 (depends on 38) The article of claim 38 in which said array of microcubes comprises rows of said microcubes in which each row of microcubes is a replica of a structure that has been ruled on the end of a microthick plate. ### Claim 45 (depends on 44) The article of claim 44 in which said array comprises rows of rectangular microcubes in which each row is a replica of a structure that has been ruled on the end of a microthick plate by a bevel face formed along the end of the plate and a plurality of v-grooves substantially perpendicular to the bevel face. ### Claim 46 (depends on 45) The article of claim 45 in which adjacent rows of said microcubes correspond to adjacent plates oriented 180° to each other. ### Claim 47 (depends on 44) The article of claim 44 in which said array comprises microcubes present as opposed paired microcubes, and in which said array comprises pairs of rows of rectangular microcubes in which each pair of rows is a replica of a structure that has been ruled on the end of a microthick plate by a v-groove extending along the center of the plate end, with opposed pairs of v-grooves extending substantially perpendicular to the center v-groove. ### Claim 48 (depends on 38) The article of claim 38 in which said array of male microcubes comprises at least three consecutive rows of said microcubes in which each row of microcubes is a replica of a structure that has been ruled on the end of a microthick plate having a thickness of less than 1 mm. ### Claim 49 (depends on 34) The article of claim 34 in which the microthick plate has a thickness of (a)-(b): (a) less than 1 mm, or (b) 0.012 inch (0.305 mm) or less. ### Claim 50 (depends on 44) The article according to claim 44 in which the microthick plate has a thickness of (a)-(b): (a) less than 1 mm, or (b) 0.012 inch (0.305 mm) or less. ### Claim 51 (depends on 48) The article of claim 48 in which the microthick plate has a thickness of 0.012 inch (0.305 mm) or less. ### Claim 52 (depends on 27) The article of claim 27 in which a plurality of said microcubes are male microcubes at least some of which have no dihedral face edges collinear with any dihedral face edges of any adjacent microcubes.