Method of manufacturing directional backlight apparatus and directional structured optical film
Disclosed is a manufacturing method for a stepped imaging directional backlight apparatus which may include a structured optical film and a tapered body. The structured optical film may include multiple optical functions and may be assembled by folding onto the tapered body, reducing cost and complexity of manufacture.
1. A stepped waveguide comprising:
a tapered optical body comprising substantially planar sides that are tapered with respect to each other, and further sides extending between the planar sides;
a substrate disposed on the tapered optical body, the substrate comprising a polymer film; and
a structured optical film arranged with the tapered optical body, the structured optical film formed on the substrate, the structured optical film comprising a light extraction region and an edge region, wherein the light extraction region comprises a plurality of guiding features and a plurality of extraction features, wherein the extraction features and the guiding features are connected to and alternate with one another respectively, and the edge region of the structured optical film comprises a reflective Fresnel element,
the light extraction region of the structured optical film being attached to one of the planar sides of the optical body, the structured optical film being folded such that the edge region of the structured optical film is attached to one of the further sides of the optical body.
2. A stepped imaging directional waveguide according to claim 1 , wherein
the further sides include sides at the ends of the waveguide in a direction in which the substantially planar sides are tapered, being a thick further side and a thin further side, and
the edge region of the structured optical film is attached to the thick further side.
3. A stepped waveguide according to claim 2 , wherein the structured optical film further comprises a further edge region, the further edge region of the structured optical film comprising an input optical element the further edge region of the structured optical film being folded and attached to the thin further side.
4. A stepped waveguide according to claim 3 , wherein the input optical element comprises an optical diffuser.
5. An illumination apparatus comprising:
a stepped waveguide according to claim 4 ; and
an array of light sources disposed at different input positions across the thin further side and arranged to input light into the waveguide through the thin further side.
6. A stepped waveguide according to claim 3 , wherein the input optical element comprises a colored filter, a cross-talk reduction layer, or an array of input facets.
7. An illumination apparatus comprising:
a stepped waveguide according to claim 6 ; and
an array of light sources disposed at different input positions across the thin further side and arranged to input light into the waveguide through the thin further side.
8. An illumination apparatus comprising:
a stepped waveguide according to claim 3 ; and
an array of light sources disposed at different input positions across the thin further side and arranged to input light into the waveguide through the thin further side.
9. An illumination apparatus comprising:
a stepped waveguide according to claim 2 ; and
an array of light sources disposed at different input positions across the thin further side and arranged to input light into the waveguide through the thin further side.
10. A stepped waveguide according to claim 1 , wherein the structured optical film comprises plural edge regions, each edge region comprising a further optical element, the plural edge regions of the structured optical film being folded and attached to different ones of the further sides.
11. A stepped waveguide according to claim 10 , wherein the further sides include two lateral sides arranged laterally of a direction in which the substantially planar sides are tapered, and
the plural edge regions of the structured optical film include two edge regions attached to the two lateral sides, and
the further optical element comprises a metallized portion.
12. A stepped waveguide according to claim 1 , wherein the extraction features are elongate and curved along their length.
13. A stepped waveguide according to claim 1 , wherein the further optical element has a surface relief portion.
14. A stepped waveguide according to claim 1 , wherein the tapered optical body is made of plastic or glass.
15. A stepped waveguide according to claim 1 , wherein the structured optical film is attached to the optical body by a bonding layer disposed between the substrate and the optical body.
16. A stepped waveguide according to claim 15 , wherein the bonding layer provides an index matching interface between the structured optical film and the optical body.