Flexible border allowing vertical translation of membrane for fluid-filled lens
A flexible border for a liquid lens serves as a transition to allow movement at an edge of a membrane that is part of the liquid lens, thereby reducing distortion caused by the “beam effect” of the membrane securely attached to an anchor point. The flexible border allows vertical translation of an end of a membrane portion.
1. A device for use as a liquid lens, the device comprising:
a substrate;
a membrane portion, wherein the membrane portion is flexible;
a fluid filling a gap between the substrate and the membrane portion;
a periphery confining the fluid within a shape of the periphery; and
a joint portion, wherein:
the joint portion couples the membrane portion with the periphery;
the joint portion is configured to allow an end of the membrane portion adjacent to the joint portion to move in a translation motion in relation to the periphery; and
the end of the membrane portion is defined by a discontinuity in a surface of the membrane portion.
2. The device of claim 1 , wherein the joint portion is thinner than the membrane portion and has a serpentine cross section.
3. The device of claim 1 , wherein:
the translation motion is a vertical motion, and
vertical is defined in a direction of beam propagation.
4. The device of claim 1 , wherein the joint portion is made of a same material as the membrane portion.
5. The device of claim 1 , wherein the joint portion comprises a metal.
6. The device of claim 1 , wherein the joint portion follows the shape of the periphery.
7. The device of claim 1 , wherein the end of the membrane portion has a non-elliptical shape in a plane orthogonal to beam propagation.
8. The device of claim 1 , wherein the shape of the periphery is non-elliptical.
9. The device of claim 1 , wherein the shape of the periphery includes an edge and a corner.
10. The device of claim 9 , wherein:
the edge of the periphery is defined by a first radius of curvature,
the corner of the periphery is defined by a second radius of curvature, and
the first radius of curvature is at least four times the second radius of curvature.
11. The device of claim 10 , wherein a first thickness of the joint portion at the edge is less than a second thickness of the joint portion at the corner.
12. The device of claim 10 , wherein:
the joint portion has a width defined by a distance from the membrane portion to the periphery, and
the width of the joint portion increases as the membrane portion moves in relation to the periphery.
13. A method of using a liquid lens, the method comprising:
applying pressure to a membrane portion of the liquid lens to move the membrane portion in relation to a periphery of the liquid lens, wherein the liquid lens comprises:
a substrate;
the membrane portion, wherein the membrane portion is flexible;
a fluid filling a gap between the substrate and the membrane portion;
the periphery confining the fluid within a shape of the periphery; and
a joint portion, wherein:
the joint portion couples the membrane portion with the periphery;
the joint portion is configured to allow an end of the membrane portion adjacent to the joint portion to move in relation to the periphery; and
the end of the membrane portion is defined by a discontinuity in a surface of the membrane portion;
moving the end of the membrane portion in a translation motion relative to the periphery using the joint portion based on applying pressure to the membrane portion; and
transmitting light through the liquid lens after translating the end of the membrane portion, whereby beam effect is reduced compared to a liquid lens without a joint.
14. The method of claim 13 , further comprising:
moving the membrane portion from a neutral position to decrease a focal length of the liquid lens, and
increasing a width of the joint portion based on moving the membrane portion from the neutral position to decrease the focal length of the liquid lens.
15. The method of claim 13 , wherein there is less translation of the end of the membrane portion near a corner of the periphery than at an edge of the periphery because a thickness of the joint portion at the corner of the periphery is greater than the thickness of the joint portion at the edge of the periphery.
16. The method of claim 13 , wherein:
the joint portion follows the shape of the periphery, and
the shape of the periphery is non-elliptical.
17. A system comprising:
a frame;
a display mounted in the frame;
a waveguide in the display; and
a liquid lens configured to change focus of light exiting the waveguide, the liquid lens comprising:
a substrate;
a membrane portion, wherein the membrane portion is flexible;
a fluid filling a gap between the substrate and the membrane portion;
a periphery confining the fluid within a shape of the periphery; and
a joint portion, wherein:
the joint portion couples the membrane portion with the periphery;
the joint portion is configured to allow an end of the membrane portion adjacent to the joint portion to move in a translation motion in relation to the periphery; and
the end of the membrane portion is defined by a discontinuity in a surface of the membrane portion.
18. The system as recited in claim 17 , wherein:
the liquid lens is a first liquid lens, and
the system further comprises a second liquid lens, and
the second liquid lens is configured to counteract effects of the first liquid lens for an object imaged on an opposite side of the display in relation to a user's eye.
19. The system as recited in claim 17 , wherein the joint portion follows the shape of the periphery.
20. The system as recited in claim 17 , wherein the shape of the periphery is non-elliptical.