Optical substrate and transparent routing of light sources
A structure includes a first transparent conductive layer, a second transparent conductive layer, and an insulation layer disposed between the first transparent conductive layer and the second transparent conductive layer. A light source having a first node and a second node may have its first node electrically coupled to the first transparent conductive layer and its second node electrically coupled to the second transparent conductive layer. A via running though one of the transparent conductive layers may facilitate electrical routing to the light source.
1. A device comprising:
a transparent substrate;
a first transparent conductive layer disposed over the transparent substrate;
a second transparent conductive layer;
an insulation layer disposed between the first transparent conductive layer and the second transparent conductive layer;
a light source having a first node and a second node, the first node electrically coupled to the first transparent conductive layer and the second node electrically coupled to the second transparent conductive layer, wherein the light source is configured to emit non-visible light in an eyebox direction for eye-tracking;
an activation layer adhering to the second transparent conductive layer; and
a conductive pad coupled to the activation layer, wherein the second node of the of the light source is electrically coupled to the second transparent conductive layer through the activation layer and the conductive pad.
2. The device of claim 1 , wherein the second node of the light source is wire-bonded to the second transparent conductive layer.
3. The device of claim 1 , wherein the light source is configured to emit the non-visible light through the first transparent conductive layer and the transparent substrate, and wherein a source light void in the second transparent conductive layer is disposed between the first node and the second node.
4. The device of claim 1 , wherein the first node and the second node of the light source are on a bottom side of the light source.
5. The device of claim 1 further comprising:
a die window void sized to accommodate a footprint of the light source, wherein the die window void is through the insulation layer and the second transparent conductive layer.
6. The device of claim 1 further comprising:
a conductive epoxy layer coupled between the first node of the light source and the first transparent conductive layer.
7. The device of claim 1 , wherein the first node is coupled to the first transparent conductive layer through a via running through the second transparent conductive layer and the insulation layer.
8. The device of claim 1 , wherein the light source includes a light emitting diode (LED) having an anode and a cathode, and wherein the first node of the light source is the cathode or anode.
9. The device of claim 1 , wherein the light source includes a vertical-cavity surface-emitting laser (VCSEL).
10. The device of claim 1 , wherein the first transparent conductive layer includes indium tin oxide, and wherein the second transparent conductive layer includes indium tin oxide.
11. The device of claim 1 , further comprising a near-eye optical element, wherein the transparent substrate, the first transparent conductive layer, the second transparent conductive layer, and the insulation layer are included in the near-eye optical element for positioning within 50 mm of a human eye.
12. The device of claim 1 , wherein the non-visible light is near-infrared (NIR) light.
13. A device of an eye-tracking system, the device comprising:
a first transparent conductive layer, wherein the first transparent conductive layer is segmented into a plurality of conductive column traces;
a second transparent conductive layer segmented into a plurality of conductive row traces;
an insulation layer disposed between the first transparent conductive layer and the second transparent conductive layer; and
an array of light sources having a first node and a second node, wherein the first node is electrically coupled to one of the conductive column traces, and wherein the second node is electrically coupled to one of the conductive row traces, wherein the array of light sources is configured to emit non-visible light in an eyebox direction for eye-tracking.
14. The device of claim 11 , further comprising a lens or an optical combiner of a head mounted display (HMD), wherein the first transparent conductive layer, the second transparent conductive layer, the insulation layer, and the array of light sources are included in the lens or the optical combiner for positioning within 50 mm of a human eye.
15. The device of claim 13 , wherein the non-visible light is near-infrared (NIR) light.
16. The device of claim 13 further comprising:
illumination logic coupled to selectively illuminate the array of light sources by selectively providing electrical power to the conductive column traces or the conductive row traces.
17. The device of claim 13 , wherein the conductive column traces are electrically isolated from each other and the conductive row traces are electrically isolated from each other.
18. The device of claim 13 , wherein the conductive row traces are disposed approximately orthogonal to the conductive column traces.
19. The device of claim 11 , wherein the near-eye optical element is a lens or an optical combiner of a head mounted display (HMD).