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 lens comprising:
a deformable membrane comprising:
a first conductive layer and a second conductive layer,
a first piezoelectric membrane layer positioned between the first conductive layer and a ground layer, and
a second piezoelectric membrane layer positioned between the second conductive layer and the ground layer,
wherein in response to a first voltage being applied to a first portion of the first conductive layer and a second voltage being applied to a second portion of the first conductive layer, a first portion of the first piezoelectric membrane layer deforms such that a first portion of the deformable membrane has a first curvature associated with a first optical power and, concurrently, a second portion of the first piezoelectric membrane layer deforms such that a second portion of the deformable membrane has a second curvature associated with a second optical power that is different than the first optical power; and
a transparent fluid enclosed between a substrate layer and the deformable membrane,
wherein an optical power of the lens is based in part on an index of refraction of the transparent fluid.
2 . The lens of claim 1 , wherein the substrate layer has a curvature such that the curvature provides optical power to the lens.
3 . The lens 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 lens 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 lens of claim 1 , wherein, responsive to the first voltage applied to the first conductive layer and the second voltage applied to the first conductive layer, the deformable membrane curves to provide a fixed optical power to the lens.
6 . The lens of claim 1 , wherein at least one of the first conductive layer and the second conductive layer comprises a plurality of branched conductive wires.
7 . The lens of claim 1 , wherein at least one of the first piezoelectric membrane layer and the second piezoelectric membrane layer is composed of polyvinylidene fluoride.
8 . The lens of claim 1 , wherein the lens has a continuous range of optical powers.
9 . The lens of claim 1 , wherein the transparent fluid has a refractive index that is between 1.2 to 2.5.
10 . The lens of claim 1 , wherein the substrate layer is transparent to light in an optical band.
11 . The lens of claim 10 , wherein the optical band is selected from a group consisting of visible light and infrared light.
12 . A head-mounted display (HMD) comprising:
a lens comprising:
a deformable membrane comprising:
a first conductive layer and a second conductive layer,
a first piezoelectric membrane layer positioned between the first conductive layer and a ground layer, and
a second piezoelectric membrane layer positioned between the second conductive layer and the ground layer,
wherein in response to a first voltage being applied to a first portion of the first conductive layer and a second voltage being applied to a second portion of the first conductive layer, a first portion of the first piezoelectric membrane layer deforms such that a first portion of the deformable membrane has a first curvature associated with a first optical power and, concurrently, a second portion of the first piezoelectric membrane layer deforms such that a second portion of the deformable membrane has a second curvature associated with a second optical power that is different than the first optical power; and
a transparent fluid enclosed between a substrate layer and the deformable membrane, wherein an optical power of the lens is based in part on an index of refraction of the transparent fluid.
13 . The HMD of claim 12 , wherein the substrate layer has a curvature such that the curvature provides optical power to the lens.
14 . The HMD of claim 12 , wherein, responsive to the first voltage applied to the first conductive layer and the second voltage applied to the first conductive layer, the deformable membrane curves to provide a fixed optical power to the lens.
15 . The HMD of claim 12 , wherein at least one of the first conductive layer and the second conductive layer comprises a plurality of branched conductive wires.
16 . The HMD of claim 12 , wherein the substrate layer is transparent to light in an optical band.