Lamina comprising cube corner elements and retroreflective sheeting

• US 7,261,426 B2
• Filed: 09/25/2006
• Issued: 08/28/2007
• Est. Priority Date: 03/06/2003
• Status: Expired due to Term

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Smith, Kenneth L.
• Primary Examiner(s): Cherry; Euncha P.
• Application Number:
  US11/534,767
• Publication Number:
  US 20070014010A1
• Time in Patent Office: 337 Days
• Field of Search: 359/529, 359/530, 359/546
• US Class Current: 359/530
• CPC Class Codes: B29C 59/007 Forming single grooves or ribs, e.g. tear lines, weak spots by moulding B29C37/0057; folding lines B29C53/06; in metal articles B21D17/00; by cutting B26D3/08
• CPC Class Codes: B29D 11/00605 Production of reflex reflectors
• CPC Class Codes: B29L 2011/0091 Reflex reflectors
• CPC Class Codes: G02B 1/10 Optical coatings produced by application to, or surface treatment of, optical elements G02B1/08 takes precedence
• CPC Class Codes: G02B 1/18 Coatings for keeping optical surfaces clean, e.g. hydrophobic or photo-catalytic films G02B1/16 takes precedence
• CPC Class Codes: G02B 5/122 cube corner, trihedral or triple reflector type
• CPC Class Codes: G02B 5/124 plural reflecting elements forming part of a unitary plate or sheet
• CPC Class Codes: Y10T 156/1082 Partial cutting bonded sandwich [e.g., grooving or incising]
• CPC Class Codes: Y10T 428/2457 Parallel ribs and/or grooves

Abstract

The present invention is directed to lamina(e) comprising cube corner elements, a tool comprising an assembly of laminae and replicas thereof. The invention further relates to retroreflective sheeting.

Claims

1. An article comprising preferred geometry cube corner elements wherein at least one cube comprises a 1-2 dihedral angle error and a 1-3 dihedral angle error;

wherein the dihedral angle errors vary in opposition.

2. The article of claim 1 wherein the cube comprises dihedral angle errors having magnitudes between 1 are minute and 60 are minutes.

3. The article of claim 1 wherein the elements are in a row having dihedral edges that range from being nominally parallel to nonparallel by less than 1°

.

4. The article of claim 1 wherein the dihedral angle errors are varied in a repeating pattern.

5. An article comprising at least one preferred geometry cube corner element having three dihedral angles errors wherein the dihedral angle errors are different from each other.

6. The article of claim 5 wherein the dihedral angle errors have magnitudes between 1 are minute and 60 are minutes.

7. The article of claim 5 comprising a plurality of the elements in a row wherein at least one dihedral edge of the elements range from being nominally parallel to nonparallel by less than 1°

.

8. The article of claim 7 wherein the dihedral angle errors of the elements are varied in a repeating pattern.

9. The article of claim 7 wherein the article comprises a lamina.

10. The article of claim 7 wherein the elements each have a first face and the first faces define a primary groove face.

11. The article of claim 7 wherein the article comprises a tool.

12. The article of claim 7 wherein the article comprises retroreflective sheeting.

13. The article of claim 12 wherein the retroreflective sheeting comprises cube corner elements.

14. The article of claim 12 wherein the retroreflective sheeting comprises cube corner cavities.