LIGHT COUPLING INTO ILLUMINATED FILMS

• US 20100214786A1
• Filed: 10/07/2008
• Published: 08/26/2010
• Est. Priority Date: 10/09/2007
• Status: Active Grant

• Current Assignee: FLEx Lighting II, LLC
• Original Assignee: FLEx Lighting II, LLC
• Inventors: Nichol, Anthony J.
• Granted Patent: US 8,714,781 B2
• Time in Patent Office: Days
• US Class Current: 362/296.10
• CPC Class Codes: G02B 6/0018 Redirecting means on the surface of the light guide
• CPC Class Codes: G02B 6/0076 Stacked arrangements of multiple light guides of the same or different cross-sectional area
• CPC Class Codes: Y10S 362/812 Signs
• CPC Class Codes: Y10T 29/49826 Assembling or joining
• CPC Class Codes: Y10T 29/49888 Subsequently coating

Abstract

A flexible translucent sheet is folded to have portions of its bounding edge closely situated in overlapping relationship, and these overlapping portions are illuminated by a light source. The illumination is transmitted through the interior of the sheet to any adjacent unfolded area of the sheet, which may bear emission areas which are treated so that the light emits from the sheet at these areas. Preferred versions of the invention have a series of legs cut into one edge of the sheet, and the legs are then bundled in stacked relationship, with a light source providing light input into the bundle.

Claims

1. A film illumination system including:

a. a flexible sheet of at least partially translucent material, the sheet having;

(1) a bounding edge;

(2) a folded portion wherein the sheet is folded upon itself such that portions of the bounding edge overlap; and

(3) an unfolded portion wherein the sheet is not folded upon itself;

b. a light source adjacent the overlapping portions of the bounding edge.

2. The film illumination system of claim 1 wherein the sheet is sufficiently flexible that it can be rolled upon itself with a radius of curvature of less than 50 times the thickness of the sheet.

3. The film illumination system of claim 1 wherein the sheet is sufficiently flexible that it can be rolled upon itself with a radius of curvature of less than 25 times the thickness of the sheet.

4. The film illumination system of claim 1 wherein the sheet bears a layer of at least one of:

a. reflective material, and

b. material having a lower refractive index.

5. The film illumination system of claim 1 wherein an area on the surface of the sheet is:

a. roughened, and/or

b. rendered less translucent or reflective,

to reduce internal reflection of light within the sheet at or adjacent the area.

6. The film illumination system of claim 1 wherein:

a. at least a portion of the sheet fluoresces when exposed to light at an activating wavelength;

b. the light source emits light at the activating wavelength.

7. The film illumination system of claim 1 wherein the overlapping portions of the bounding edge are at least substantially aligned to define an at least substantially smooth and continuous surface.

8. The film illumination system of claim 1 wherein:

a. the flexible sheet has discrete legs defined therein, wherein each portion of the bounding edge situated adjacent an overlapping portion is provided on one of the discrete legs, and

b. at least some of the legs are folded to have the portions of the bounding edge overlap.

9. A film illumination system including:

a. a flexible sheet of at least partially translucent material wherein;

(1) the sheet has several discrete legs extending therefrom, each leg terminating at a bounding edge;

(2) the legs are stacked, with their bounding edges being at least substantially aligned;

b. a light source adjacent the bounding edges of the stacked legs.

10. The film illumination system of claim 9 wherein at least some of the legs are folded between their bounding edges and the sheet.

11. The film illumination system of claim 9 wherein the sheet is sufficiently flexible that it can be rolled upon itself with a radius of curvature of less than 75 times the thickness of the sheet.

12. The film illumination system of claim 9 wherein the sheet is sufficiently flexible that it can be rolled upon itself with a radius of curvature of less than 35 times the thickness of the sheet.

13. The film illumination system of claim 9 wherein the sheet bears, upon at least one of its opposing faces, a layer of at least one of:

a. reflective material, and

b. material having a lower refractive index.

14. The film illumination system of claim 9 wherein:

a. the sheet has one or more areas which are;

(1) roughened, and/or

(2) rendered less translucent or reflective,

to reduce internal reflection of light within the sheet at or adjacent the area, and

b. the areas are collectively at least 1% of the area of the sheet, exclusive of the legs.

15. The film illumination system of claim 9 wherein:

a. at least a portion of the sheet fluoresces when exposed to light at an activating wavelength;

b. the light source emits light at the activating wavelength.

16. A film illumination system including:

a. a flexible sheet of at least partially translucent material including;

(1) a body;

(2) several legs joined to the body, the legs each having a bounding edge from which the leg extends to join the body, wherein at least some of the legs are bent so that their bounding edges are adjacently situated;

b. a light source oriented to illuminate the adjacently situated bounding edges of the stacked legs.

17. The film illumination system of claim 16 wherein the sheet is sufficiently flexible that a leg can be rolled upon itself from its bounding edge with a radius of curvature of less than 60 times the thickness of the sheet.

18. The film illumination system of claim 16 wherein the sheet bears, upon at least one of its opposing faces, a layer of material which promotes internal reflection within the film.

19. The film illumination system of claim 16 wherein:

a. the sheet has one or more discrete areas which have enhanced emission of light in comparison to their surrounding areas within the sheet, and

b. the areas having enhanced emission of light each have a minor dimension which is at least three times greater than the thickness of the sheet.

20. The film illumination system of claim 16 wherein:

a. at least a portion of the sheet fluoresces when exposed to light at an activating wavelength, and

b. the light source emits light at the activating wavelength.