LIGHT DIRECTING FILM

• US 20110199557A1
• Filed: 04/27/2011
• Published: 08/18/2011
• Est. Priority Date: 05/31/2006
• Status: Abandoned Application

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Johnson, Todd M., Marushin, Patrick H., Toma, Tetsuya
• Application Number:
  US13/095,341
• Publication Number:
  US 20110199557A1
• Time in Patent Office: Days
• US Class Current: 349/62
• CPC Class Codes: G02B 5/045 Prism arrays
• CPC Class Codes: G02B 6/0053 Prismatic sheet or layer; Brightness enhancement element, sheet or layer
• CPC Class Codes: G02F 1/133504 Diffusing, scattering, diffracting elements associated to illuminating devices G02F1/133606

Abstract

A light directing film and an optical system incorporating same are disclosed. The light directing film includes a first major surface and a microstructured second major surface. The microstructured second major surface has at least two periodic microstructured patterns. The first periodic pattern is arranged along a first direction. The second periodic pattern is arranged along a second direction different from the first direction.

Claims

1. A light directing film comprising a first major surface and a second major surface, the second major surface having a two-dimensional microstructured pattern superimposed on a one-dimensional periodic microstructured pattern.

2. The light directing film of claim 1, wherein the two-dimensional microstructured pattern is periodic along at least one direction.

3. The light directing film of claim 1, wherein the two-dimensional microstructured pattern is periodic along at least two different directions.

4. The light directing film of claim 1, wherein each microstructure in the one-dimensional and two-dimensional patterns has a peak and a peak height measured from the peak to a common reference plane disposed between the first and second major surfaces, and wherein the heights of the microstructures in the one-dimensional periodic microstructured pattern are different than the heights of the microstructures in the two-dimensional microstructured pattern.

5. The light directing film of claim 4, wherein at least two microstructures in the two-dimensional microstructured pattern have different heights.

6. The light directing film of claim 1, wherein at least two microstructures in the two-dimensional microstructured pattern have different shapes.

7. The light directing film of claim 1, wherein the microstructures in the one- and two-dimensional patterns extend along a same direction.

8. The light directing film of claim 1, wherein at least some of the microstructures in the one- and two-dimensional patterns are prismatic.

9. A light guide assembly for use in a liquid crystal display, the light guide assembly comprising at least one light directing film of claim 1.

10. A light directing film comprising a first major surface and a second major surface, the second major surface having a two-dimensional regularly-spaced pattern of discrete elements disposed on a one-dimensional periodic microstructured pattern.

11. The light directing film of claim 10, wherein at least some of the discrete elements are microstructured.