Wide-angle-reflective cube-corner retroreflective sheeting

• US 4,703,999 A
• Filed: 06/16/1986
• Issued: 11/03/1987
• Est. Priority Date: 06/16/1986
• Status: Expired due to Term

• Current Assignee: 3M Company
• Original Assignee: 3M Company
• Inventors: Benson, Gerald M.
• Primary Examiner(s): Arnold, Bruce Y.
• Assistant Examiner(s): Ben, Loha
• Application Number:
  US06/874,537
• Time in Patent Office: 505 Days
• Field of Search: 350/102, 350/103
• US Class Current: 359/532
• CPC Class Codes: G02B 5/124 plural reflecting elements forming part of a unitary plate or sheet

Abstract

Cube-corner retroreflectors having a rear surface configured with a cube-corner reflective element are made capable of reflecting light over a wide range of incident angles by placing a specularly reflective surface shaped as a negative of the cube-corner reflective element in closely spaced mating relationship with said rear surface.

Claims

1. Cube-corner retroreflector capable of reflecting light over a wide range of incidence angles comprising a transparent body configured on its rear surface with at least one set of three mutually perpendicular surfaces providing cube-corner retroreflection of light beamed against the front of the body, and a specularly reflective layer having a specularly reflective surface which is shaped as a negative of said set of three mutually perpendicular surfaces and which is interfitted with and closely spaced from said set of surfaces, with the adjacent and matching portions of the specularly reflective and rear surfaces being substantially parallel to one another.

2. Cube-corner retroreflector of claim 1 in which the transparent body is configured on its rear surface with a plurality of sets of three mutually perpendicular surfaces, and the specularly reflective layer is shaped as a negative of said sets of three mutually perpendicular surfaces.

3. Cube-corner retroreflective sheeting capable of reflecting light over a wide range of incidence angles comprising a transparent sheet configured on its rear surface with cube-corner retroreflective elements which retroreflect light beamed against the front of the sheet, and a reflector sheet having a specularly reflective surface which is a negative of the configured rear surface of the transparent sheet and which is interfitted with and closely spaced from said rear surface, with the adjacent and matching portions of the specularly reflective and rear surfaces being substantially parallel to one another.

4. Sheeting of claim 3 in which the specularly reflective surface is spaced from said rear surface on average by no more than about 25 percent of the height of the cube-corner retroreflective elements.

5. Sheeting of claim 3 in which said reflector sheet comprises a specularly reflective layer that was originally deposited on a surface configured with cube-corner retroreflective elements, and a backing applied to the deposited specularly reflective layer to which the specularly reflective layer preferentially adheres.

6. Flexible sheeting of claim 3 capable of being wound into a roll about a 2.5-centimeter-diameter mandrel.