Minnesota Mining and Manufacturing Company

3m Innovative Properties Company

Matthew R Atkinson

Olester Benson, Jr

Cheryl M Frey

Paul E Marecki

Jeanine M Shusta

Harlan L Krinke

Joseph R Zwack

A confocal scanning microscope includes a light source which provides a light beam and scanning optics which sweep the light beam across the surface of a sample. Light from the surface or interior of the sample passes through a pinhole lens which focuses the light on a pinhole for detection by an optical detector. An image of the surface may be scanned using the optical detector. An optical element is inserted in a detection arm of the confocal microscope. The optical element provides angular magnification and natural divergence to the beam from the surface of the sample.

High resolution confocal microscope

A glittering non-retroreflective sheeting 60 includes an array of cube-corner elements 30 that are arranged in the array such that the sheeting glitters when light is incident thereon. The glitter is in the form of many discrete points of light 68 that tend to blink off and on. The array may be configured such that a dihedral angle .alpha. varies between adjacent cube faces 31 of adjacent cube-corner elements 30 in each groove in one of the groove sets 45, 46, or 47 and such that the base plane 36 are not parallel to each other when the sheeting 60 is laid flat. Preferably, the dihedral angle .alpha. between faces 31 of adjacent cube-corner elements 30 varies in essentially all of the grooves such that the cube-corner elements are randomly tilted throughout the array. The glitter can make the sheeting very useful for aesthetic or decorative applications.

Glittering cube-corner article

A cube-corner retroreflective sheeting 60 includes an array of cube-corner elements 30 that are defined by three sets of intersecting parallel grooves 45, 46, 47. The cube-corner elements 30 are arranged in the array such that the sheeting 60 glitters when exposed to light. The glitter is in the form of many discreet points of light that tend to blink on and off when viewed by the naked eye. The array may be configured such that a dihedral angle .alpha. varies between adjacent cube faces 31 of adjacent cube-corner elements 30 in each groove in one of the groove sets 45, 46, or 47 and such that base planes are not parallel to each other when the sheeting 60 is laid flat. Preferably, the dihedral angle .alpha. between faces 31 of adjacent cube-corner elements 30 varies in essentially all of the grooves such that the cube-corner elements are randomly tilted throughout the array. The sheeting glitters very well under daytime viewing conditions and also to some extent under nighttime or retroreflective conditions. The glittering effect can enhance the sheeting's conspicuity, and hence highlight a person's presence to give them improved safety and security.

Glittering cube-corner retroreflective sheeting

A mold 79 that includes an array of cube-corner elements 80 that are arranged in the array such that a retroreflective cube-corner sheeting 60 that is formed thereon is capable of glittering when light is incident on the sheeting. The array may be defined by three sets of intersecting grooves 25, 26, 27 where each groove set includes two or more generally parallel grooves. At least one groove in at least one of the sets has faces 22 of adjacent cube-corner elements 30a, 30b arranged such that a dihedral angle .alpha. located between adjacent faces varies along the groove(s) in the set.

Mold for producing glittering cube-corner retroreflective sheeting

A method of making a glittering cube-corner sheeting, which method includes: (a) providing a first retroreflective sheeting that includes an array of cube-corner elements arranged in a repeating pattern; and (b) exposing the first retroreflective sheeting to heat, pressure, or a combination thereof to produce a second retroreflective sheeting that comprises an array of cube-corner elements that are randomly tilted; or which method may comprise: (a) providing a mold that has a structured surface that includes a multiplicity of cube-comer elements, the cube-corner elements each including a base plane and three faces, the cube-corner elements being arranged such that the base planes do not reside in the same plane when the sheeting is laid flat; and (b) forming a cube-corner sheeting from the mold.

Method of making glittering cube-corner retroreflective sheeting

A retroreflective sheeting having a multiplicity of discrete, cube-corner elements cured in situ on a transparent, polymeric overlay film deformed into a three-dimensional structure so that base edges of a plurality of cube-corner elements are non-planar with respect to one another. The retroreflective article preferably has at least one target optical property. The present invention is also directed to a method of deforming the retroreflective sheeting to form a retroreflective article in which the base edges of a plurality of cube-corner elements are non-planar with respect to one another.

Growing community of inventors

Cottage Grove, MN, United States of America

Matthew R Atkinson