MICROREPLICATED FILMS HAVING DIFFRACTIVE FEATURES ON MACRO-SCALE FEATURES

• US 20090147361A1
• Filed: 12/07/2007
• Published: 06/11/2009
• Est. Priority Date: 12/07/2007
• Status: Abandoned Application

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Ehnes, Dale L., Gardiner, Mark E., Jones, Vivian W.
• Application Number:
  US11/952,438
• Publication Number:
  US 20090147361A1
• Time in Patent Office: Days
• US Class Current: 359/566
• CPC Class Codes: G02B 5/04 Prisms
• CPC Class Codes: G02B 5/1852 using mechanical means, e.g. ruling with diamond tool, moulding

Abstract

An optical film having a substrate and microreplicated features on a major surface of the substrate. The features include microreplicated macro-scale features and one or more microreplicated diffractive features on the macro-scale features. The films can be made from work pieces machined with tool tips having diffractive features. The tool tip forms both the macro-scale features and diffractive features while machining the work piece. A coating process can then be used to make the optical films from the machined work piece.

Claims

1. An optical film, comprising:

a substrate;

a plurality of microreplicated macro-scale features formed on a major surface of the substrate; and

one or more microreplicated diffractive features formed on the macro-scale features,

wherein the substrate and the macro-scale features are formed of a substantially light transmissive material.

2. The optical film of claim 1, wherein the macro-scale features comprise prisms having opposing facets and vertices.

3. The optical film of claim 2, wherein the diffractive features comprise triangular notches on at least one of the facets of the prisms.

4. The optical film of claim 2, wherein the diffractive features comprise triangular notches on only one of the facets of the prisms.

5. The optical film of claim 2, wherein the diffractive features comprise a series of adjoining lenslets on at least one of the facets of the prisms.

6. The optical film of claim 2, wherein the diffractive features comprise a grating with a series of raised portions on at least one of the facets of the prisms.

7. The optical film of claim 2, wherein the diffractive features comprise a grating with a series of angled portions on at least one of the facets of the prisms.

8. The optical film of claim 2, wherein the diffractive features comprise one or more triangular notches on at least one of the facets of the prisms along with a flat portion between the notches and the vertices of the prisms.

9. The optical film of claim 2, wherein the diffractive features comprise triangular notches on the vertices of the prisms, and wherein the vertices are flat.

10. The optical film of claim 2, wherein the diffractive features comprise triangular notches on the vertices of the prisms, and wherein the vertices are curved.

11. The optical film of claim 2, wherein the diffractive features comprise a series of adjoining steps on at least one of the facets of the prisms.

12. The optical film of claim 2, wherein the diffractive features comprise a series of adjoining lenslets on the vertices of the prisms, and wherein the vertices are flat.

13. The optical film of claim 2, wherein the diffractive features comprise a series of adjoining curved portions on at least one of the facets of the prisms.

14. The optical film of claim 2, wherein the diffractive features comprise a series of adjoining angled flat portions on at least one of the facets of the prisms.

15. The optical film of claim 1, wherein the macro-scale features are continuous.

16. The optical film of claim 1, wherein the macro-scale features are discontinuous.

17. The optical film of claim 1, wherein the macro-scale features have a constant pitch.

18. The optical film of claim 1, wherein the macro-scale features have a variable pitch.

19. An optical film, comprising:

a substrate;

a plurality of microreplicated macro-scale features formed on a major surface of the substrate, wherein the macro-scale features function to recycle visible light when the film is placed in a backlight; and

one or more microreplicated diffractive features formed on the macro-scale features, wherein the diffractive features function to diffuse visible light when the film is placed in a backlight,

wherein the substrate and the macro-scale features are formed of a substantially light transmissive material.

20. The optical film of claim 19, wherein the macro-scale features comprise prisms having opposing facets and vertices, and wherein the diffractive features comprise triangular notches on at least one of the facets of the prisms.