LIGHT DIRECTING EXPANDABLE ENVELOPE

• US 20120081908A1
• Filed: 10/01/2010
• Published: 04/05/2012
• Est. Priority Date: 10/01/2010
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Harms, Michael R., Behymer, Lance E., Wilhelm, Justin W., Smeenk, Lars A., Aguirre, Luis A., Smith, Mark H., Bierbaum, Felix, Stensvad, Karl K.
• Granted Patent: US 8,789,981 B2
• Time in Patent Office: Days
• US Class Current: 362/310
• CPC Class Codes: F21V 3/026 being inflatable
• CPC Class Codes: G02B 1/043 Contact lenses
• CPC Class Codes: G02B 5/0231 the surface having microprismatic or micropyramidal shape macroscopic prism arrays G02B5/045
• CPC Class Codes: G02B 5/0273 characterized by the use
• CPC Class Codes: G02B 5/0294 adapted to provide an additional optical effect, e.g. anti-reflection or filter
• CPC Class Codes: G02B 5/3025 Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state G02B5/3008, G02B5/3016 take precedence

Abstract

Disclosed is an expandable envelope that comprises a light directing film this both transmits and reflects light. In its inflated form and along with a light source, the envelope forms a light balloon that due to the light directing film provides directed light to an area surrounding the balloon.

Claims

1. An expandable envelope comprising a film that forms an external surface of the envelope, wherein at least a portion of the film is a light directing film.

2. The envelope of claim 1, wherein the light directing film transmits at least 20% and reflects at least 20% of a lambertian light.

3. The envelope of claim 1, wherein the light directing film comprises a structured light directing film.

4. The envelope of claim 1, wherein the structured light directing film comprises a plurality of linear structures extending along a same direction.

5. The envelope of claim 4, wherein the linear structures are prismatic.

6. The cavity of claim 1, wherein the light directing film comprises a reflective polarizer.

7. The envelope of claim 6, wherein the reflective polarizer is multilayered.

8. The envelope of claim 1, wherein the light directing film is in a flat plane at the external surface of the envelope.

9. The envelope of claim 1, wherein the external surface of the envelope comprises a plurality of flat plane sections of the light directing film.

10. The envelope of claim 1, wherein at least a portion of the light directing film is in a curved plane at the external surface of the envelope.

11. The envelope of claim 1, wherein the envelope is airtight.

12. The envelope of claim 1, further comprising a valve for introducing a medium within the envelope to expand the envelope.

13. The envelope of claim 1, further comprising a bladder within the envelope that is airtight for expanding the envelope.

14. The envelope of claim 1, wherein at least a portion of the film is a reflective film.

15. The envelope of claim 14, wherein a reflective portion of the reflective film is at an internal surface of the envelope.

16. The envelope of claim 14, wherein the light directing film is located opposite to the reflective film.

17. The envelope of claim 14, wherein at least 25% of the surface area of the envelope is the reflective film.

18. The envelope of claim 14, wherein at least 25% of the surface area of the envelope is the light directing film.

19. The envelope of claim 1, further comprising a light source.

20. An expandable envelope comprising:

a film that forms an external surface of the envelope, wherein at least a portion of the film is a light directing film that transmits at least 20% and reflects at least 20% of a lambertian light and at least a portion of the film is a reflective film;

a light source for introducing light into the envelope.