Optical lens assemblies and related methods
The disclosed optical lens assemblies may include a pre-strained deformable element that exhibits a non-uniform mechanical strain or stress profile, a structural support element coupled to the pre-strained deformable element, and a deformable medium positioned between the pre-strained deformable element and the structural support element. Related head-mounted displays and methods of fabricating such optical lens assemblies are also disclosed.
1. An optical lens assembly, comprising:
a substantially transparent pre-strained deformable element that exhibits at least one of a non-uniform mechanical strain or stress profile such that, when the deformable element is deformed into a curved shape, an optical axis of the optical lens assembly is in a different location than a geometric center of the optical lens assembly, wherein the non-uniform mechanical strain or stress profile is a result of pre-straining the deformable element; and
a substantially transparent structural support element coupled to the deformable element.
2. The optical lens assembly of claim 1 , wherein the non-uniform mechanical strain or stress profile is a result of a variable pre-tension applied to the deformable element.
3. The optical lens assembly of claim 1 , wherein the non-uniform mechanical strain profile has a variability of at least about two percent.
4. The optical lens assembly of claim 1 , wherein the non-uniform mechanical stress profile has a variability of at least about five percent.
5. The optical lens assembly of claim 1 , wherein the optical lens assembly is positioned in a head-mounted display.
6. The optical lens assembly of claim 5 , wherein the head-mounted display comprises augmented-reality glasses.
7. The optical lens assembly of claim 1 , further comprising a display element positioned adjacent to the deformable element, such that the display element is viewable by the user through the deformable element.
8. The optical lens assembly of claim 1 , further comprising a deformable medium positioned between the deformable element and the structural support element.
9. The optical lens assembly of claim 1 , further comprising an eye-tracking element configured for tracking an eye of a user.
10. A method of fabricating an optical lens assembly, the method comprising:
inducing at least one of a non-uniform mechanical strain or stress profile in a substantially transparent deformable element by pre-straining the deformable element, wherein the non-uniform mechanical strain or stress profile results in an optical axis of the optical lens assembly that is in a different location than a geometric center of the optical lens assembly when the deformable element is deformed into a curved shape; and
coupling the deformable element to a substantially transparent structural support element.
11. The method of claim 10 , wherein inducing the non-uniform mechanical strain or stress profile in the deformable element comprises
conditioning a material of the deformable
element.
12. The method of claim 11 , wherein conditioning the material of the deformable element comprises thermoforming a polymer to a non-planar profile.
13. The method of claim 11 , wherein conditioning the material of the deformable element comprises at least one of:
selectively exposing portions of the material of the deformable element to heat to induce residual strain or stress in the material of the deformable element; or
selectively polymerizing portions of the material of the deformable element to induce residual strain or stress in the material of the deformable element.
14. The method of claim 10 , wherein inducing the non-uniform mechanical strain or stress profile in the deformable element comprises stretching a material of the deformable element by at least one of:
uniaxially stretching the material of the deformable element;
biaxially stretching the material of the deformable element; or
stretching the material of the deformable element along at least one axis that is angled from vertical and horizontal relative to an intended orientation of the optical lens assembly when in use.
15. A head-mounted display, comprising:
an optical lens assembly, comprising:
a substantially transparent pre-strained deformable element that exhibits at least one of a non-uniform mechanical strain or stress profile such that, when the deformable element is deformed into a curved shape, an optical axis of the optical lens assembly is in a different location than a geometric center of the optical lens assembly, wherein the non-uniform mechanical strain or stress profile is a result of pre-straining the deformable element;
an electronic display element positioned adjacent to the optical lens assembly and configured to display images to a user through the optical lens assembly; and
a frame element physically supporting the optical lens assembly and the electronic display element.
16. The head-mounted display of claim 15 , wherein the optical lens assembly further comprises a substantially transparent structural support element coupled to the deformable element.
17. The head-mounted display of claim 16 , wherein the substantially transparent structural support element comprises a lens having a rigidity greater than the deformable element.
18. The head-mounted display of claim 16 , wherein the substantially transparent structural support element comprises a corrective optical lens.
19. The head-mounted display of claim 16 , wherein the substantially transparent structural support element comprises an eye-tracking element configured for tracking an eye of the user.
20. The head-mounted display of claim 15 , further comprising an additional optical lens assembly positioned on an opposite side of the electronic display element relative to the optical lens assembly.