Mechanical joint for use in fiber optic imaging systems

• US 10,732,355 B2
• Filed: 10/08/2019
• Issued: 08/04/2020
• Est. Priority Date: 05/31/2017
• Status: Active Grant

• Current Assignee: Magic Leap, Inc.
• Original Assignee: Magic Leap, Inc.
• Inventors: Zhang, Xiaoyang, Mathur, Vaibhav, Johnson, Michael Robert, Dalrymple, Timothy Mark, Duenner, Andrew C., Carlomagno, Albert Daniel
• Primary Examiner(s): Rahll, Jerry
• Application Number:
  US16/596,263
• Publication Number:
  US 20200049895A1
• Time in Patent Office: 301 Days
• Field of Search: None
• CPC Class Codes: G02B 2027/0187 slaved to motion of at least a part of the body of the user, e.g. head, eye
• CPC Class Codes: G02B 26/103 having movable or deformable optical fibres, light guides or waveguides as scanning elements light guides per se G02B6/00
• CPC Class Codes: G02B 27/017 Head mounted
• CPC Class Codes: G02B 6/262 Optical details of coupling light into, or out of, or between fibre ends, e.g. special fibre end shapes or associated optical elements
• CPC Class Codes: G02B 6/3604 Rotary joints allowing relative rotational movement between opposing fibre or fibre bundle ends
• CPC Class Codes: G02B 6/3624 Fibre head, e.g. fibre probe termination optical details of light guide terminations G02B6/241; reshaping of light guides G02B6/2552; optical details of coupling light into or out of fibre end G02B6/262
• CPC Class Codes: G02B 6/3644 the coupling means being through-holes or wall apertures
• CPC Class Codes: G02B 6/3656 the additional structures being micropositioning, with microactuating elements for fine adjustment, or restricting movement, into two dimensions, e.g. cantilevers, beams, tongues or bridges with associated MEMs

Abstract

An example apparatus includes an optical fiber, an actuator, and a joint mechanically coupling the actuator to the optical fiber. The joint includes a neck extending along an axis. The optical fiber is threaded through an aperture extending along the axis through the neck. The optical fiber is attached to the joint at a surface of the neck facing the axis. The joint also includes a collar extending along the axis. The actuator is mechanically attached to the joint at an inner surface of the collar facing the axis. The joint also includes a flexural element extending radially from the neck to the collar. During operation, the joint couples a force from the actuator to the optical fiber to vary an orientation of a portion of the optical fiber extending from the neck with respect to the axis.

Claims

1. A method comprising:

directing light from a light source into an optical fiber, the optical fiber being threaded through an aperture of a neck of a mechanical joint, the mechanical joint being mechanically attached to an actuator along an inner surface of a collar of the mechanical joint, the neck and the collar being mechanically coupled via a flexural element extending from the neck to the collar; and

operating the actuator to vary an orientation of a first end of the optical fiber extending from the mechanical joint according to a spiral pattern.

2. The method of claim 1, further comprising:

emitting the light from the first end of the optical fiber towards a subject.

3. The method of claim 1, wherein the subject is a user'"'"'s eye.

4. The method of claim 1, further comprising:

generating a light modulation signal and a drive signal;

generating, using the light source, the light according to a light modulation signal; and

operating the actuator according to the drive signal.

5. The method of claim 4, wherein the light modulation signal regulates an output of the light source in accordance with the spiral pattern.

6. The method of claim 5, wherein the drive signal regulates an operation of the actuator to vary the orientation of the first end of the optical fiber according to the spiral pattern.

7. The method of claim 5, further comprising emitting the light from the first end of the optical fiber to form an image on an image plane.

8. The method of claim 1, wherein operating the actuator comprises coupling a mechanical force generated by the actuator to the optical fiber using the mechanical joint.

9. The method of claim 8, wherein the flexural element of the mechanical joint comprises one or more beams extending between the neck and the collar, and wherein the mechanical force generated by actuator is coupled to optical fiber, at least in part, through the one or more beams.

10. The method of claim 8, wherein the flexural element of the mechanical joint comprises a gimbal structure, and wherein the mechanical force generated by actuator is coupled to optical fiber, at least in part, through the gimbal structure.

11. The apparatus of claim 1, wherein the flexural element defines one or more slots extending through the flexural element, the one or more slots being spirally arranged about the axis.

12. The apparatus of claim 1, wherein the flexural element comprises a gimbal structure.

13. An apparatus, comprising:

an optical fiber;

an actuator configured to generate a force to vary an orientation of a first end of the optical fiber according to a spiral pattern; and

a joint mechanically coupling the actuator to the optical fiber, wherein the joint is configured to couple the force generated by the actuator to the optical fiber, and wherein the joint comprises;

a neck extending along an axis, the optical fiber being threaded through an aperture extending along the axis through the neck, wherein the optical fiber is attached to the joint at a surface of the neck facing the axis,

a collar extending along the axis, wherein the actuator is mechanically attached to the joint at an inner surface of the collar facing the axis, and

a flexural element extending radially from the neck to the collar.

14. The apparatus of claim 13, wherein the optical fiber is configured to emit the light from the first end of the optical fiber towards a subject.

15. The apparatus of claim 13, wherein the subject is a user'"'"'s eye.

16. The apparatus of claim 13, further comprising:

a drive module configured to generate a light modulation signal; and

a light source configured to generate light according to the light modulation signal and provide the light to a second end of the optical fiber opposite the first end, wherein the light modulation signal regulates an output of the light source in accordance with the spiral pattern.

17. The apparatus of claim 16, wherein the drive module is configured to generate a drive signal, wherein the drive signal regulates an operation of the actuator to vary the orientation of the first end of the optical fiber according to the spiral pattern.

18. The apparatus of claim 17, wherein the apparatus comprises a head mounted display device.

19. The apparatus of claim 13, wherein the actuator comprises a plurality of piezoelectric elements azimuthally spaced about the axis.

20. The apparatus of claim 19, wherein the plurality of piezoelectric elements are azimuthally spaced equally about the axis.

21. The apparatus of claim 19, wherein the plurality of piezoelectric elements are azimuthally spaced 90°

about the axis.

22. The apparatus of claim 13, wherein the flexural element comprises one or more beams extending between the neck and the collar.

23. The apparatus of claim 13, wherein the joint has a first stiffness with respect to the axis, a second stiffness with respect to a first radial direction, and a third stiffness with respect to a second radial direction orthogonal the first radial direction, and

wherein the first stiffness is greater than the second stiffness and the third stiffness.

24. The apparatus of claim 13, wherein the joint comprises crystalline silicon.

25. The apparatus of claim 13, wherein the joint comprises amorphous silicon.

26. The apparatus of claim 13, wherein the joint comprises one or more layers of silicon and one or more layers of electrically insulative material.

27. The apparatus of claim 13, wherein the neck defines one or more slots along a periphery of the neck.