Metallized retroreflective sheeting with increased daytime brightness
View Patent ↗A retroreflective sheeting ( 10 ) comprising a cube layer ( 20 ) having a front light-receiving surface ( 30 ) and a rear retroreflecting surface ( 32 ), and a metallic layer ( 22 ) covering the rear retroreflecting surface ( 32 ). The rear surface ( 32 ) comprises an array of retroreflective elements ( 34 ) and diffusing patches ( 36 ) within such array (without retroreflective elements ( 34 )). The metallic layer ( 22 ) covers the retroreflective elements ( 34 ) and the diffusing patches ( 36 ), whereby diffusing patches ( 36 ) scatter incoming light increasing daytime brightness to a desired level.
1. Retroreflective sheeting ( 10 ) comprising:
a cube layer ( 20 ) having a front light-receiving surface ( 30 ) and a rear retroreflecting surface ( 32 ), and
a metallic layer ( 22 ) covering the rear retroreflecting surface ( 32 );
wherein the retroreflective rear surface ( 32 ) of the cube layer ( 20 ) comprises an array of retroreflective elements ( 34 ) and a diffusing patch ( 36 ) within such array without retroreflective elements ( 34 ); and
wherein the metallic layer ( 22 ) covers the retroreflective elements ( 34 ) and the diffusing patch ( 36 ).
2. Retroreflective sheeting ( 10 ) as set forth in claim 1 , wherein the retroreflective elements ( 34 ) each comprise cube corner elements having three approximately mutually perpendicular faces ( 40 ) that intersect at a cube apex ( 42 ).
3. Retroreflective sheeting ( 10 ) as set forth in claim 2 , wherein the retroreflective elements ( 34 ) are selected from a group including triangle, hexagonal, square and rectangle cube corner elements.
4. Retroreflective sheeting ( 10 ) as set forth in claim 1 , wherein the retroreflective elements ( 36 ) comprise micro-optical elements.
5. Retroreflective sheeting ( 10 ) as set forth in claim 1 , comprising a plurality of diffusing patches ( 36 ) within the array of retroreflective elements ( 34 ).
6. Retroreflective sheeting ( 10 ) as set forth in claim 1 , wherein the metallic layer ( 22 ) covers each of the plurality of diffusing patches ( 36 ).
7. Retroreflective sheeting ( 10 ) as set forth in claim 1 , wherein each diffusing patch ( 36 ) has a coverage area greater than the occupation area of a plurality of retroreflective elements ( 34 ).
8. Retroreflective sheeting ( 10 ) as set forth in claim 7 , wherein two or more retroreflective elements ( 34 ) could fit within the coverage area of the diffusing patch ( 36 ).
9. Retroreflective sheeting ( 10 ) as set forth in claim 8 , wherein five or more retroreflective elements ( 34 ) could fit within the coverage area of the diffusing patch ( 36 ).
10. Retroreflective sheeting ( 10 ) as set forth in claim 9 , wherein ten or more retroreflective elements ( 34 ) could fit within the coverage area of the diffusing patch ( 36 ).
11. Retroreflective sheeting ( 10 ) as set forth in claim 1 , wherein the diffusing patch ( 36 ) does not contain any recognizable retroreflective elements ( 34 ).
12. Retroreflective sheeting ( 10 ) as set forth in claim 1 , wherein the coverage area of the diffusing patch ( 36 ) has an outer perimeter having linear sections parallel with perimeter edges ( 44 ) of the retroreflective elements ( 34 ).
13. Retroreflective sheeting ( 10 ) as set forth in claim 12 , wherein the outer perimeter's linear sections are aligned with perimeter edges ( 44 ) of surrounding retroreflective elements ( 34 ).
14. Retroreflective sheeting ( 10 ) as set forth in claim 12 , wherein the coverage area of the diffusing patch ( 36 ) occupies the entire area within the outer perimeter.
15. Retroreflective sheeting ( 10 ) as set forth in claim 12 , wherein the coverage area of the diffusing patch ( 36 ) has an inner perimeter and retroreflective elements ( 34 ) are positioned within this inner perimeter.
16. Retroreflective sheeting ( 10 ) as set forth in the claim 15 , wherein the inner perimeter has linear sections parallel with perimeter edges ( 44 ) of the retroreflective elements ( 34 ).
17. Retroreflective sheeting ( 10 ) as set forth in claim 16 , wherein the inner perimeter's linear sections are aligned with perimeter edges ( 44 ) of the retroreflective elements ( 34 ) surrounded by the inner perimeter.
18. Retroreflective sheeting ( 10 ) as set forth in claim 1 , characterized by the absence of any daytime brightness-increasing pigment on the front surface ( 30 ) of the cube layer ( 20 ).
19. Retroreflective sheeting ( 10 ) as set forth in claim 1 , characterized by the absence of an overlay layer in front of the front surface ( 30 ) of the cube layer ( 20 ).
20. Retroreflective sheeting ( 10 ) as set forth in claim 1 , wherein the cube layer ( 20 ) is a colored layer.
21. Retroreflective sheeting ( 10 ) as set forth in claim 1 , wherein the metallic layer ( 22 ) is a coated or deposited layer.
22. Retroreflective sheeting ( 10 ) as set forth in claim 21 , wherein the metallic layer ( 22 ) is selected from a group including aluminum, vaporized metal or combinations thereof.
23. Retroreflective sheeting ( 10 ) as set forth in claim 1 , wherein the diffusing patch covers ten percent or higher of the cube layer.
24. Retroreflective sheeting ( 10 ) as set forth in claim 1 , wherein the diffusing patch covers twenty percent or higher of the cube layer.
25. Retroreflective sheeting ( 10 ) as set forth in claim 1 , wherein the diffusing patch covers between thirty percent to eighty percent of the cube layer.