Curved light guide for thin structure illumination
Systems are generally described that include a curved light guide for thin structure illumination. An example system includes a light sub-assembly comprising a curved light sub-assembly backing ring and a plurality of light-emitting diodes (LEDs), each LED of the plurality of LEDs being coupled to the curved light sub-assembly backing ring. The example system also includes a curved light guide having an edge coupled to the light sub-assembly, the curved light guide including a pattern of optical extraction features that distribute light and are positioned on the exterior surface of the curved light guide for uniformly distributing light from the plurality of LEDs. The example system also includes a curved reflector including an exterior surface coupled to an interior surface of the curved light guide, wherein the exterior surface is reflective, and a volumetric diffuser coupled to the exterior surface of the curved light guide.
1 . An electronic projector device comprising:
a movable projector sub-assembly comprising:
at least one processor,
at least one memory electronically coupled to the at least one processor,
a projector illumination source,
a projector lens positioned to project light from the projector illumination source onto a surface, and
a motorized positioning subsystem configured to adjust a direction of light projected by the movable projector sub-assembly;
a light sub-assembly comprising:
a curved light sub-assembly backing ring, and
a plurality of light-emitting diodes (LEDs), each LED of the plurality of LEDs being coupled to the curved light sub-assembly backing ring;
a curved light guide having an edge coupled to the light sub-assembly, the curved light guide comprising:
a pattern of optical extraction features that distribute light from the plurality of LEDs to an exterior surface of the curved light guide, the pattern of optical extraction features positioned on the exterior surface of the curved light guide with areal density based on a local curvature of the curved light guide for uniformly distributing light from the plurality of LEDs;
a curved reflector comprising an exterior surface coupled to an interior surface of the curved light guide, wherein the exterior surface is reflective, wherein an interior surface of the curved reflector surrounds the at least one processor and the at least one memory; and
a volumetric diffuser coupled to the exterior surface of the curved light guide,
wherein the light sub-assembly, the curved light guide, the curved reflector, and the volumetric diffuser each comprise a notch allowing the motorized positioning subsystem to reposition the projector lens about an axis parallel to a ceiling.
2 . The electronic projector device of claim 1 , wherein the curved light guide, the curved reflector, and the volumetric diffuser each have a hemispheric shape, wherein the areal density of the optical extraction features is based on a latitudinal position on the curved light guide.
3 . The electronic projector device of claim 1 , wherein the optical extraction features are hemispherical protrusions on the surface of the curved light guide, wherein a hemisphere radius and a hemisphere height of each optical extraction feature vary based on the local curvature of the curved light guide.
4 . A device comprising:
a light sub-assembly comprising a plurality of light-emitting diodes (LEDs);
a curved light guide having an edge coupled to the light sub-assembly;
a curved reflector comprising an exterior surface coupled to an interior surface of the curved light guide, wherein the exterior surface is reflective; and
a volumetric diffuser coupled to the exterior surface of the curved light guide,
wherein:
an interior of the device is hollow,
the interior is bounded by an interior surface of the curved reflector,
the light sub-assembly, the curved light guide, the curved reflector, and the volumetric diffuser each comprise a notch positioned along a latitudinal arc of the device, and
the notch forms a gap in the device allowing access to the interior of the device.
5 . The device of claim 4 , further comprising a curved light sub-assembly backing ring, wherein each LED of the plurality of LEDs is coupled to the curved light sub-assembly backing ring.
6 . The device of claim 5 , wherein the curved light sub-assembly backing ring comprises an aluminum core.
7 . The device of claim 4 , wherein the plurality of LEDs comprises a 2835 surface mount device (SMD) chip.
8 . The device of claim 4 , wherein the curved light guide comprises a pattern of optical extraction features positioned on an exterior surface of the curved light guide.
9 . The device of claim 8 , wherein the pattern of optical extraction features is positioned with areal density based on a local curvature of the curved light guide.
10 . The device of claim 8 , wherein an optical extraction feature from the pattern of optical extraction features is a hemispherical protrusion on the surface of the curved light guide.
11 . The device of claim 10 , wherein a radius of the hemispherical protrusion is based on a local curvature of the curved light guide, wherein a height of the hemispherical protrusion is based on the local curvature of the curved light guide.
12 . The device of claim 4 , wherein the curved reflector further comprises a raised lip around the edge of the notch positioned to reflect light away from the notch.
13 . The device of claim 4 , wherein the exterior surface of the curved reflector has at least 85% reflectance.
14 . The device of claim 4 , wherein the curved light guide comprises polymethyl methacrylate, wherein the curved light guide has at least 90% light transmission through three millimeters of material.
15 . The device of claim 4 , wherein the volumetric diffuser comprises plastic material, wherein the plastic material comprises 8% polyurethane material, wherein the volumetric diffuser has at least 20% light transmission.
16 . The device of claim 4 , wherein the curved light guide is fabricated using a turning process directed by computer numerical control.
17 . The device of claim 4 , comprising a movable projector sub-assembly, positioned inside the curved light guide, comprising:
a projector illumination source,
a projector lens positioned to project light from the projector illumination source onto a surface, and
a motorized positioning subsystem configured to adjust a direction of light projected by the movable projector sub-assembly.
18 . The device of claim 17 , wherein the projector lens is positioned within the notch.