Liquid lens structure with adjustable optical power
A liquid lens structure has an adjustable and continuous range of optical power. The liquid lens structure comprises a substrate layer and a deformable membrane which enclose a volume of liquid. The substrate layer is at least partially transparent in the optical band. The deformable membrane comprises a ground layer, two membrane layers, and two conductive layers. Each of the two conductive layers control electrical voltage applied to one of the membrane layers in reference to the ground layer, wherein each membrane layer deforms in response to applied electrical voltage. The deformation of the two membrane layers adjusts a curvature of the deformable membrane which provides the adjustable continuous range of optical power to the liquid lens structure.
1. A liquid lens structure comprising:
a substrate layer; and
a deformable membrane configured to provide a continuous range of optical power to the liquid lens structure, the deformable membrane comprising:
a first conductive layer,
a first membrane layer positioned between the first conductive layer and a ground layer, wherein the membrane layer deforms in response to the first voltage applied to the first conductive layer,
a second conductive layer,
a second membrane layer positioned between the second conductive layer and the ground layer, wherein the membrane layer deforms in response to a second voltage applied to the second conductive layer, and
wherein a volume of liquid is enclosed between the substrate layer and the deformable membrane.
2. The liquid lens structure of claim 1 , wherein the substrate layer has a curvature such that the curvature provides optical power to the liquid lens structure.
3. The liquid lens structure of claim 1 , wherein at least one of the first conductive layer and the second conductive layer, comprises a plurality of non-intersecting conductive wires.
4. The liquid lens structure of claim 1 , wherein at least one of the first conductive layer and the second conductive layer, comprises a plurality of conductive wires arranged in a crosshatch pattern.
5. The liquid lens structure of claim 1 , wherein, responsive to the first voltage applied to the first conductive layer and the second voltage applied to the second conductive layer, the deformable membrane curves such that it provides a fixed optical power, of the continuous range of optical powers, to the liquid lens structure.
6. The liquid lens structure of claim 1 , wherein at least one of the first conductive layer and the second conductive layer, includes a plurality of addressable nodes that includes a first set and a second set, and the liquid lens structure is configured to apply a third voltage to the first set of addressable nodes to cause a corresponding first portion of the deformable membrane to have a first curvature and to apply a fourth voltage to the second set of addressable nodes to cause a corresponding second portion of the deformable membrane to have a second curvature that is different than the first curvature.
7. The liquid lens structure of claim 1 , wherein at least one of the first conductive layer and the second conductive layer, comprises a plurality of branched conductive wires.
8. The liquid lens structure of claim 1 , wherein at least one of the first membrane layer and the second membrane layer is composed of a piezoelectric material.
9. The liquid lens structure of claim 8 , wherein the piezoelectric material is polyvinylidene fluoride.
10. The liquid lens structure of claim 1 , wherein the continuous range of optical power to the liquid lens structure includes at least a range of 0 to 2 diopters.
11. The liquid lens structure of claim 1 , wherein the liquid of the volume of liquid has a refractive index that is between 1.2 to 2.5.
12. The liquid lens structure of claim 1 , wherein the substrate layer is transparent to light in an optical band.
13. The liquid lens structure of claim 12 , wherein the optical band is selected from a group consisting of visible light and infrared light.
14. A head-mounted display (HMD) comprising:
a liquid lens structure comprising:
a substrate layer; and
a deformable membrane configured to provide a continuous range of optical power to the liquid lens structure, the deformable membrane comprising:
a first conductive layer,
a first membrane layer positioned between the first conductive layer and a ground layer, wherein the membrane layer deforms in response to the first voltage applied to the first conductive layer,
a second conductive layer,
a second membrane layer positioned between the second conductive layer and the ground layer, wherein the membrane layer deforms in response to a second voltage applied to the second conductive layer, and
wherein a volume of liquid is enclosed between the substrate layer and the deformable membrane.
15. The HMD of claim 14 , wherein the substrate layer has a curvature such that the curvature provides optical power to the liquid lens structure.
16. The HMD of claim 14 , wherein, responsive to the first voltage applied to the first conductive layer and the second voltage applied to the second conductive layer, the deformable membrane curves such that it provides a fixed optical power, of the continuous range of optical powers, to the liquid lens structure.
17. The HMD of claim 14 , wherein at least one of the first conductive layer and the second conductive layer, includes a plurality of addressable nodes that includes a first set and a second set, and the liquid lens structure is configured to apply a third voltage to the first set of addressable nodes to cause a corresponding first portion of the deformable membrane to have a first curvature and to apply a fourth voltage to the second set of addressable nodes to cause a corresponding second portion of the deformable membrane to have a second curvature that is different than the first curvature.
18. The HMD of claim 14 , wherein at least one of the first conductive layer and the second conductive layer, comprises a plurality of branched conductive wires.
19. The HMD of claim 14 , wherein at least one of the first membrane layer and the second membrane layer is composed of a piezoelectric material.
20. The HMD of claim 14 , wherein the substrate layer is transparent to light in an optical band.