Lens assembly including a silicone fresnel lens

Patent metadata

Field	Value
Publication number	US-10705340-B2
Application number	US-201715432799-A
Country	US
Kind code	B2
Filing date	Feb 14, 2017
Priority date	Feb 14, 2017
Publication date	Jul 7, 2020
Grant date	Jul 7, 2020

Abstract

A lens assembly and a method of making the assembly are described. The lens assembly includes a first lens and a second lens slidably coupled with the first lens. The second lens includes a silicone material and has a Fresnel pattern surface. Also described is a display device including the lens assembly and an array of light emitting devices coupled with the lens assembly for outputting light through the lens assembly.

First claim

What is claimed is:

1. A lens assembly, comprising:
a first lens; and
a second lens that includes silicone material and has a surface with a Fresnel pattern, wherein the second lens is slidably coupled with the first lens so that the first lens slides relative to the second lens in a direction that is substantially parallel to an optical axis of the first lens or the second lens.

2. The lens assembly of claim 1 , wherein:
the first lens includes polymethylmethacrylate (PMMA).

3. The lens assembly of claim 1 , wherein:
the second lens includes a plurality of guides that are slidably coupled with the first lens.

4. The lens assembly of claim 3 , wherein:
a plurality of through-holes are defined in the first lens; and
the plurality of through-holes are configured to mate with the plurality of guides.

5. The lens assembly of claim 4 , further comprising:
a lock configured for conditionally preventing a sliding motion of the second lens relative to the first lens.

6. The lens assembly of claim 1 , wherein:
the first lens includes a plurality of guides that are slidably coupled with the second lens.

7. The lens assembly of claim 6 , wherein:
a plurality of through-holes are defined in the second lens; and
the plurality of through-holes are configured to mate with the plurality of guides.

8. The lens assembly of claim 7 , further comprising:
a lock configured for conditionally preventing a sliding motion of the second lens relative to the first lens.

9. The lens assembly of claim 6 , further comprising:
an actuator configured to move the first lens and/or the second lens so as to change a distance between the first lens and the second lens.

10. The lens assembly of claim 1 , wherein:
the first lens is rotationally symmetric; and
the second lens is rotationally symmetric.

11. The lens assembly of claim 1 , wherein:
the Fresnel pattern is defined by a surface profile function; and
a derivative of the surface profile function has one or more discontinuities.

12. A display device, comprising:
the lens assembly of claim 1 ; and
an array of light emitting devices coupled with the lens assembly for outputting light through the lens assembly.

13. The display device of claim 12 , wherein the display device is a head-mounted display device.

14. The display device of claim 13 , wherein the array of light emitting devices is configured to output light and transmit the light through the lens assembly toward an eye of a user when the display device is worn on a head of the user.

15. A method for making a lens assembly, the method comprising:
providing a first lens;
providing a second lens that includes silicone material and has a surface with a Fresnel pattern; and
slidably coupling the first lens with the second lens so that the first lens slides relative to the second lens in a direction that is substantially parallel to an optical axis of the first lens or the second lens.

16. The method of claim 15 , further comprising:
mechanically coupling the first lens and/or the second lens with an actuator configured to change a distance between the first lens and the second lens.

17. The method of claim 15 , further comprising:
changing a distance between the first lens and the second lens to obtain a particular magnification for the lens assembly.

18. The method of claim 17 , further comprising:
fixing the distance between the first lens and the second lens.

19. The method of claim 18 , wherein:
the first lens and the second lens are slidably coupled with a plurality of guides and a plurality of corresponding through-holes; and
fixing the distance between the first lens and the second lens includes engaging one or more locks to prevent a sliding motion of at least one guide of the plurality of guides relative to a corresponding through-hole of the plurality of through-holes.

20. The method of claim 15 , wherein:
providing the second lens includes:
providing, in a mold having a first Fresnel pattern, a silicone material comprising silicone; and
curing the silicone material in the mold to form a Fresnel lens, wherein the cured silicone material has a second Fresnel pattern that corresponds to the first Fresnel pattern.

Assignees

• Facebook Tech Llc

Inventors

• Yoon Youngshik
• Cho Richard Han Soo

Classifications

• G02B7/08

  adapted to co-operate with a remote control mechanism · CPC title

• G02B2027/0178

  Eyeglass type (eyeglass details G02C) · CPC title

• G02B2027/0187

  slaved to motion of at least a part of the body of the user, e.g. head, eye · CPC title

• G02B27/0093

  with means for monitoring data relating to the user, e.g. head-tracking, eye-tracking · CPC title

• G02B2027/0161

  characterised by the relative positioning of the constitutive elements · CPC title