Back to results
US 6,120,280 AGranted
Microprism master mold
AssigneeNippon Carbide Kogyo Kabushiki Kaisha
InventorsIkuo Mimura, Keiji Adachi
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeNippon Carbide Kogyo Kabushiki Kaisha
InventorsIkuo Mimura, Keiji Adachi
Estimating the term…
A microprism master mold is formed from a plurality of flat sheets having two mutually parallel major surfaces. On one edge thereof, there is provided a series of V-shaped grooves having a bottom angle of about 90.degree. and roof-shaped projections having a vertical angle of about 90.degree., successively formed at a fixed repeating pitch and in a direction perpendicular to the major surfaces. The flat sheets are stacked so that the vertices of the roof-shaped projections formed on each flat sheet meet the bottoms of the V-shaped grooves formed on an adjacent flat sheet. The microprism master mold includes two or more different types of roof-shaped projections and the thickness of each flat sheet is equal to 0.6-2.0 times the length of the shorter oblique sides of the roof-shaped projections. The master mold is useful for production of cube-corner type retroreflectors characterized by microprism having high brightness and excellent wide-angle properties. The retroreflective sheeting produced with the microprism master mold may be thin and flexible.
A microprism master mold comprising a plurality of flat sheets having two mutually parallel major surfaces and provided on one edge thereof with a series of V-shaped grooves having a bottom angle of about 90.degree. and roof-shaped projections having a vertical angle of about 90.degree. which are successively formed at a fixed repeating pitch and in a direction perpendicular to the major surfaces, said flat sheets being stacked so that the vertices of the roof-shaped projections formed on each flat sheet meet the bottoms of the V-shaped grooves formed on an adjacent flat sheet, characterized in that said microprism master mold includes two or more different roof-shaped projections and in that the thickness of each flat sheet is equal to 0.6-2.0 times the length of the shorter oblique sides of the roof-shaped projection.
A microprism master mold comprising a plurality of flat sheets having two mutually parallel major surfaces and provided on one edge thereof with a series of V-shaped grooves having a bottom angle of about 90.degree. and roof-shaped projections having a vertical angle of about 90.degree. which are successively formed at a fixed repeating pitch and in a direction perpendicular to the major surfaces, said flat sheets being stacked so that the vertices of the roof-shaped projections formed on each flat sheet meet the bottoms of the V-shaped grooves formed on an adjacent flat sheet, characterized in that said microprism master mold includes two or more different roof-shaped projections and in that the thickness of each flat sheet is equal to 0.6-2.0 times the length of the shorter oblique sides of the roof-shaped projections, and wherein the two or more different roof-shaped projections are roof-shaped projections having two or more different vertical angles.
A microprism master mold comprising a plurality of flat sheets having two mutually parallel major surfaces and provided on one edge thereof with a series of V-shaped grooves having a bottom angle of about 90.degree. and roof-shaped projections having a vertical angle of about 90.degree. which are successively formed at a fixed repeating pitch and in a direction perpendicular to the major surfaces said flat sheets being stacked so that the vertices of the roof-shaped projections formed on each flat sheet meet the bottoms of the V-shaped grooves formed on an adjacent flat sheet, characterized in that said microprism master mold includes two or more different roof-shaped projections and in that the thickness of each flat sheet is equal to 0.6-2.0 times the length of the shorter oblique sides of the roof-shaped projections, and wherein the shape of the roof-shaped projections is asymmetrical.
Dependencies are inferred from the claim text.