Lamina comprising cube corner elements and retroreflective sheeting

• US 7,722,197 B2
• Filed: 06/22/2009
• Issued: 05/25/2010
• Est. Priority Date: 03/06/2003
• Status: Active Grant

• 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:
  US12/489,056
• Publication Number:
  US 20090257124A1
• Time in Patent Office: 337 Days
• Field of Search: 359/529, 359/530, 156/247, 156/268, 264/1.9, 428/167
• US Class Current: 359/529
• 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 disclosure is directed to lamina(e) comprising cube corner elements, a tool comprising an assembly of laminae and replicas thereof. The disclosure further relates to retroreflective sheeting.

Claims

1. Retroreflective sheeting comprising an array of preferred geometry cube corner elements that exhibit a uniformity index of at least 1 at an entrance angle of at least 30°

.

2. The retroreflective sheeting of claim 1 wherein the uniformity index is for an entrance angle of 40°

.

3. The retroreflective sheeting of claim 1 wherein the array is substantially free of tiling in more than one orientation.

4. The retroreflective sheeting of claim 1 wherein the uniformity index is at least 3.

5. The retroreflective sheeting of claim 1 wherein the uniformity index is at least 5.

6. The retroreflective sheeting of claim 1 wherein the cubes are canted having an alignment angle selected from alignment angles between 45°

and 135°

, alignment angles between 225° and

315°

, and combinations thereof.