Automobile with conformal film-based lightguide
An automobile comprises a light transmitting film with a thickness not greater than 0.5 millimeters with a core layer, a lightguide region of the film comprises a light emitting region with light extracting features positioned to receive and extract light from at least one light source propagating by total internal reflection within the core layer out of the core layer, and a light mixing region positioned between the at least one light source and the light emitting region, wherein a surface of the portion of the automobile is visible through the light emitting region of the film when the at least one light source is not emitting light and the light transmitting film is conformal with the surface of the portion of the automobile. The surface of the film may have arcuate cross-sectional shape conforming to a curved surface of the portion of the automobile.
1. An automobile comprising:
a portion of the automobile comprising a surface;
at least one light source;
a light transmitting film comprising:
a body with opposing faces and a thickness not greater than 0.5 millimeters therebetween, a core layer;
a lightguide region of the light transmitting film comprising a light emitting region with light extracting features positioned to receive and extract light from the at least one light source propagating by total internal reflection within the core layer out of the core layer in the light emitting region, and
a light mixing region positioned along an optical path between the at least one light source and the light emitting region,
wherein the surface of the portion of the automobile is visible through the light emitting region of the light transmitting film when the at least one light source is not emitting light and the light transmitting film is conformal with the surface of the portion of the automobile.
2. The automobile of claim 1 wherein the light transmitting film further comprises an array of strips extending from the lightguide region of the light transmitting film, and each strip of the array of strips is folded and stacked such that ends of the strips are positioned to receive light from the at least one light source.
3. The automobile of claim 2 wherein the ends of the strips and the at least one light source are within a light input coupler positioned within an interior region of the automobile.
4. The automobile of claim 3 wherein the lightguide region is positioned on an exterior side of the automobile.
5. The automobile of claim 1 wherein the surface of the portion of the automobile is curved and one or more surfaces of the opposing faces of the light transmitting film comprises an arcuate cross-sectional shape conforming to the surface of the portion of the automobile.
6. The automobile of claim 1 wherein the portion of the automobile comprises a window and the lightguide region of the light transmitting film is optically coupled to the window.
7. The automobile of claim 1 wherein the lightguide region is positioned within an interior of the automobile.
8. The automobile of claim 1 wherein light from the at least one light source is emitted from the light emitting region and illuminates the surface of the portion of the automobile.
9. The automobile of claim 1 further comprising a light emitting surface and a light reflecting film, the lightguide region is positioned between the light reflecting film and the light emitting surface, and the light reflecting film conforms to a shape of the light emitting region.
10. The automobile of claim 1 further comprising a reflective spatial light modulator, wherein light from the at least one light source is emitted from the light emitting region and illuminates the reflective spatial light modulator.
11. The automobile of claim 10 wherein the reflective spatial light modulator is an electrophoretic reflective spatial light modulator.
12. The automobile of claim 1 wherein the portion of the automobile comprises a door of the automobile.
13. The automobile of claim 1 wherein an average haze of the light emitting region of the light transmitting film is less than 30%.
14. The automobile of claim 1 wherein the core layer has a first refractive index, n m , the light transmitting film further comprises a cladding layer with a refractive index, coupled to the core layer where n clad , optically n m −n clad is greater than 0.01.
15. The automobile of claim 1 further comprising a light transmitting film-based lightguide positioned above the light transmitting film and a second light source different from the at least one light source positioned to emit light into the light transmitting film-based lightguide.
16. The automobile of claim 1 wherein light from the at least one light source is emitted from the light emitting region in a form of an indicia, logo, graphic, or image.
17. An automobile comprising:
a portion of the automobile comprising a curved surface;
at least one light source;
a light transmitting film comprising:
a body with opposing faces and a thickness not greater than 0.5 millimeters therebetween, a core layer;
a lightguide region of the light transmitting film comprising a light emitting region with light extracting features positioned to receive and extract light from the at least one light source propagating by total internal reflection within the core layer out of the core layer in the light emitting region;
an array of strips extending from the lightguide region of the light transmitting film, each strip of the array of strips is folded and stacked such that ends of the strips are positioned to receive light from the at least one light source; and
a light mixing region positioned between the array of strips and the light emitting region,
wherein the curved surface of the portion of the automobile is visible through the light emitting region of the light transmitting film, and one or more surfaces of the opposing faces of the light transmitting film comprises an arcuate cross-sectional shape conforming to the curved surface of the portion of the automobile.
18. The automobile of claim 17 wherein the lightguide region is positioned on an exterior side of the automobile, and light from the at least one light source is emitted from the light emitting region and illuminates the curved surface of the portion of the automobile.
19. The automobile of claim 17 further comprising a reflective spatial light modulator, wherein light from the at least one light source is emitted from the light emitting region and illuminates the reflective spatial light modulator.
20. A method of emitting light from a vehicle, the method comprising:
forming a flexible film-based lightguide with a body with opposing faces and a thickness not greater than 0.5 millimeters therebetween, a core layer, a lightguide region of the flexible film-based lightguide comprising a light emitting region with light extracting features positioned to receive and extract light from a light source propagating by total internal reflection within the core layer out of the core layer in the light emitting region;
positioning at least one light source to emit light that propagates into the flexible film-based lightguide by total internal reflection; and
applying the flexible film-based lightguide to a portion of a vehicle such that the light emitting region conforms to a surface of the vehicle.
21. The method of claim 20 wherein applying the flexible film-based lightguide to a portion of a vehicle includes thermoforming the flexible film-based lightguide into a curved shape.