公开(公告)号：CA2295071A1

公开(公告)日：1999-01-14

申请号：CA2295071

申请日：1997-11-20

Applicant: MINNESOTA MINING & MFG

Inventor： BENSON GERALD M ,  SMITH KENNETH L

IPC: B29C33/38 ,  B29D11/00 ,  G02B5/124

Abstract: A method is disclosed for manufacturing a plurality of laminae (10a, b, c, d, e, f, g, h) 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. The method includes (a) 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, (b) forming a plurality of cube corner elements on the working surfaces of the plurality of the laminae, wherein the plurality of cube corner elements have three approximately mutually perpendicular lateral faces that mutually intersect to define a cube corner element peak, and (c) removing a plurality of laminae (10c, f) from the assembly to alter the configuration of the mold surface.

公开(公告)号：CA2294805A1

公开(公告)日：1999-01-14

申请号：CA2294805

申请日：1997-11-24

Applicant: MINNESOTA MINING & MFG

Inventor： BENSON GERALD M ,  SMITH KENNETH L

IPC: G02B5/124

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~ to about 30~ 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~ range of orientation angles and/or a minimum total light return of about 5 % across such 360~ 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.

公开(公告)号：CA2294762A1

公开(公告)日：1999-01-14

申请号：CA2294762

申请日：1998-06-12

Applicant: MINNESOTA MINING & MFG

Inventor： LUTTRELL DAN E ,  SMITH KENNETH L ,  ERWIN ROBERT L ,  BENSON GERALD M

IPC: G02B5/124 ,  B29C33/38 ,  B29D11/00 ,  B29C33/42

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. The surfaces of the third groove intersect the surfaces of the plurality of structures in substantially mutually perpendicular planes to define a plurality of cube corner elements. A plurality of such laminae can be assembled to form a mold useful in the manufacture of retroreflective products such as cube corner sheeting.

公开(公告)号：AU698459B2

公开(公告)日：1998-10-29

申请号：AU6094296

申请日：1996-06-06

Applicant: MINNESOTA MINING & MFG

Inventor： SMITH KENNETH L ,  BENSON GERALD M

IPC: G09F13/16 ,  G02B5/124

Abstract: The invention provides a thin, flexible retroreflective sheeting formed from a substantially optically transparent material. The sheeting comprises a substrate having a base surface disposed in a base plane; a structured surface opposite the base surface that contains at least one array of canted cube corner element matched pairs formed by three intersecting sets of substantially parallel grooves including a primary groove set, and two sets of secondary grooves, each matched pair including a first canted cube corner element and a second canted cube corner element disposed opposite a primary groove from the first element, wherein (a) opposing cube corner elements in a given array have their symmetry axes canted in a first plane and through a predetermined cant angle measuring between 4 DEG and 15 DEG from an axis extending normally from the base; (b) the sheeting of this given array exhibits its broadest range of entrance angularity in a second plane angularly displaced from the first plane, and in a third plane, angularly displaced from the first plane; and substantially each of the cube corner element arrays is oriented such that either the second or third plane is approximately parallel with an edge of the sheeting.

公开(公告)号：CA2221189A1

公开(公告)日：1996-12-27

申请号：CA2221189

申请日：1996-06-06

Applicant: MINNESOTA MINING & MFG

Inventor： BENSON GERALD M ,  SMITH KENNETH L

IPC: G09F13/16 ,  G02B5/124

Abstract: The invention provides a thin, flexible retroreflective sheeting formed from a substantially optically transparent material. The sheeting comprises a substrate having a base surface disposed in a base plane; a structured surface opposite the base surface that contains at least one array of canted cube corner element matched pairs formed by three intersecting sets of substantially parallel grooves including a primary groove set, and two sets of secondary grooves, each matched pair including a first canted cube corner element and a second canted cube corner element disposed opposite a primary groove from the first element, wherein (a) opposing cube corner elements in a given array have their symmetry axes canted in a first plane and through a predetermined cant angle measuring between 4 DEG and 15 DEG from an axis extending normally from the base; (b) the sheeting of this given array exhibits its broadest range of entrance angularity in a second plane angularly displaced from the first plane, and in a third plane, angularly displaced from the first plane; and substantially each of the cube corner element arrays is oriented such that either the second or third plane is approximately parallel with an edge of the sheeting.

公开(公告)号：CA2173229A1

公开(公告)日：1995-04-27

申请号：CA2173229

申请日：1994-10-20

Applicant: MINNESOTA MINING & MFG

Inventor： BENSON GERALD M ,  SMITH KENNETH L

IPC: B23B3/30 ,  B23D1/20 ,  G02B5/124

Abstract: A method of machining a substrate to produce a cube corner element optical array (12). The method includes steps of directly machining a plurality of groove sets (14, 16, 20) into a directly machinable substrate to form an array having a plurality of geometric structures including cube corner elements (24, 26, 30), 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.