Light emitting device comprising a lightguide film

• US 8,905,610 B2
• Filed: 04/18/2011
• Issued: 12/09/2014
• Est. Priority Date: 01/26/2009
• Status: Active Grant

• Current Assignee: FLEx Lighting II, LLC
• Original Assignee: FLEx Lighting II, LLC
• Inventors: Coleman, Zane, Nichol, Anthony
• Primary Examiner(s): MAY, ROBERT J
• Application Number:
  US13/089,308
• Publication Number:
  US 20130155723A1
• Time in Patent Office: 1,331 Days
• Field of Search: 362/554, 362/556
• US Class Current: 362/554
• CPC Class Codes: G02B 6/0011 the light guides being planar or of plate-like form
• CPC Class Codes: G02B 6/0016 Grooves, prisms, gratings, scattering particles or rough surfaces
• CPC Class Codes: G02B 6/0018 Redirecting means on the surface of the light guide
• CPC Class Codes: G02B 6/0028 Light guide, e.g. taper
• CPC Class Codes: G02B 6/003 Lens or lenticular sheet or layer
• CPC Class Codes: G02B 6/0031 Reflecting element, sheet or layer
• CPC Class Codes: G02B 6/0036 2-D arrangement of prisms, protrusions, indentations or roughened surfaces
• CPC Class Codes: G02B 6/006 to produce indicia, symbols, texts or the like
• CPC Class Codes: G02B 6/0068 Arrangements of plural sources, e.g. multi-colour light sources
• CPC Class Codes: G02B 6/0075 Arrangements of multiple light guides G02B6/0028 takes precedence
• CPC Class Codes: G02B 6/0076 Stacked arrangements of multiple light guides of the same or different cross-sectional area
• CPC Class Codes: G02B 6/0078 Side-by-side arrangements, e.g. for large area displays
• CPC Class Codes: G02B 6/0085 Means for removing heat created by the light source from the package heat extraction or cooling elements for semiconductor light sources in general H01L33/64
• CPC Class Codes: G02B 6/0088 of the light guide or other optical sheets in the package
• CPC Class Codes: G02B 6/009 of the light source in the package G02B6/0021 takes precedence
• CPC Class Codes: G09F 9/33 being semiconductor devices, e.g. diodes
• CPC Class Codes: H01L 31/125 Composite devices with photosensitive elements and electroluminescent elements within one single body
• CPC Class Codes: Y10T 29/49716 Converting

Abstract

In one embodiment, a device includes a light transmitting film defining a body and having opposing faces with a thickness between the opposing faces not greater than 0.5 millimeters. A first region is defined within the body representing a region of one or more of a pattern, an indicia, a graphic, and an image that is visible by light extraction when illuminated by light propagating within the film in a waveguide condition. The first region includes a plurality of light extraction features that redirect a portion of light traveling within the film in a waveguide condition that mixes within the legs and the body out of one or more of the opposing faces of the film in the first region. A method of producing a device is also disclosed.

Claims

1. A device comprising:

a) a light transmitting film having a body with opposing faces and a thickness not greater than 0.5 millimeters therebetween, and an array of strips extending from the body wherein;

i. each strip of the array of strips comprises a bounding edge at an end thereof; and

ii. each strip is folded in a fold region such that the bounding edges of the array of strips are stacked;

b) a first region defined within the body configured to extract light when illuminated by light from the array of strips, the light propagating and mixing within the body in a waveguide condition;

c) at least one frame member substantially enclosing the fold regions of the stacked array of strips; and

d) a first opening defined in the at least one frame member through which an intermediate region of the light transmitting film defined between the fold regions of the stacked array of strips and the first region extends.

2. The device of claim 1 wherein the light transmitting film is physically coupled to the at least one frame member.

3. The device of claim 2 further comprising an adhesive material physically coupling the light transmitting film to the at least one frame member.

4. The device of claim 2 wherein the at least one frame member comprises at least one protruding structure and the light transmitting film defines at least one aperture or notch, and each of the at least one aperture or notch is configured to receive a corresponding one of the at least one protruding structure to physically couple the light transmitting film to the at least one frame member.

5. The device of claim 2 wherein the at least one frame member comprises a floor extending from an inner surface of the at least one frame member and the light transmitting film is physically coupled to the floor in the intermediate region.

6. The device of claim 1 wherein at least a portion of the at least one frame member has a luminous transmittance less than 50% measured according to ASTM D1003.

7. The device of claim 1 wherein at least a portion of an inner surface of the at least one frame member has a diffuse reflectance greater than 50%.

8. The device of claim 1 further comprising at least one light source positioned within the at least one frame member to emit light into the stacked bounding edges of the array of strips.

9. An illumination system comprising the device of claim 8 wherein the at least one frame member comprises an attachment structure configured to removably attach the device to the illumination system.

10. A display comprising the device of claim 8 wherein the at least one frame member comprises an attachment structure configured to removably attach the device to the display.

11. The display of claim 10 wherein the display comprises an illuminated sign.

12. The device of claim 1 further comprising a second opening in the at least one frame member positioned to allow light from an exterior of the device to propagate through the at least one frame member to the stacked bounding edges of the array of strips.

13. The device of claim 12 further comprising a light transmitting material one of disposed within and adjacent the second aperture to permit transmission of light from the exterior to the stacked bounding edges of the array of strips.

14. The device of claim 1 wherein the first region represents one or more of an indicia, a graphic, and an image that is visible by light extraction when illuminated by light propagating within the light transmitting film in the waveguide condition.

15. The device of claim 1 wherein the at least one frame member comprises an attachment structure configured to removably attach one or more of the at least one frame member and the light transmitting film to the device.

16. A light emitting device comprising:

a) a light transmitting film having a body with opposing faces, a thickness of the light transmitting film not greater than 0.5 millimeters therebetween;

b) an array of strips optically coupled to the body wherein;

i. each strip of the array of strips comprises a bounding edge at an end thereof; and

ii. each strip is folded in a fold region such that the bounding edges are stacked;

c) at least one frame member substantially enclosing the fold regions of the stacked array of strips and defming an opening;

d) at least one light source disposed to emit light into the stacked bounding edges; and

e) a light emitting region defined within the body configured to extract light from the at least one light source, the light propagating and mixing within the body in a waveguide condition after propagating through the stacked array of strips, wherein an intermediate region of the light transmitting film defined between the fold regions of the stacked array of strips and the light emitting region extends through the opening defined by the at least one frame member.

17. The light emitting device of claim 16 wherein the at least one frame member comprises an attachment feature configured to attach at least one of the light transmitting film to a frame and the frame to the light emitting device.

18. The device of claim 16 wherein at least one of the at least one frame member and a combination of the body and the array of strips is replaceable.

19. The device of claim 16 wherein the body is replaceable.