US-12625379-B2 - Lens mounting systems having a flexture around the lens

Abstract

A head-mounted device may include optical assemblies for presenting images to a user. The optical assemblies may each have a display for generating an image and a lens that presents the image to a corresponding eye box for viewing by a user. The optical assemblies may have lens barrels. Each lens barrel may have a first end to which a display is mounted and may have an opposing second end. A mount may be used to attach the lens to the second end of the lens barrel. The mount may have at least one flexure. The flexure may have a U-shaped cross-sectional shape. The mount may have a ring-shaped flexure that extends around a peripheral edge of the lens, may have flexure segments, or may have a set of three discrete flexures located at different positions along the edge of the lens.

Inventors

• Blake N Trekell
• Aidan N Zimmerman
• Clas Magnus Oscar Oldenbo
• Andrew Nichols
• Ransomed I Adebayo
• Peter Pilarz
• Jesse Melrose

Assignees

• APPLE INC.

Dates

Publication Date

20260512

Application Date

20241002

Claims (20)

1. 1 . A head-mounted device, comprising: a head-mounted housing; and optical assemblies in the head-mounted housing that are configured to provide images to eye boxes, wherein each optical assembly includes: a display, a lens barrel coupled to the display, a lens, and a flexure coupled between the lens and the lens barrel, wherein the flexure is a single, U-shaped flexure that runs around a peripheral edge of the lens.
2. 2 . The head-mounted device of claim 1 , wherein the lens comprises a catadioptric lens.
3. 3 . The head-mounted device of claim 1 , wherein the lens comprises a first material, and the flexure comprises a second material that is different from the first material.
4. 4 . The head-mounted device of claim 3 , wherein the first material comprises a first polymer, and the second material comprises a second polymer that is different from the first polymer.
5. 5 . The head-mounted device of claim 4 , wherein the second polymer comprises polyetherimide.
6. 6 . The head-mounted device of claim 5 , wherein the first polymer comprises cyclic olefin polymer.
7. 7 . The head-mounted device of claim 1 , wherein the lens barrel comprises a metal lens barrel, and the lens comprises polymer.
8. 8 . The head-mounted device of claim 7 , wherein the polymer is a first polymer, and the lens comprises a second polymer that is different from the first polymer.
9. 9 . The head-mounted device of claim 1 , wherein the single, U-shaped flexure has a U-shaped cross-section, comprises polymer, and runs around an entire perimeter of the lens.
10. 10 . A head-mounted device optical module, comprising: a support; a display coupled to the support; a lens having a peripheral edge; and a flexure including a first portion attached to the support and including a second portion attached to the peripheral edge, wherein the flexure runs around an entire perimeter of the lens.
11. 11 . The head-mounted device optical module of claim 10 , wherein the flexure comprises a material having a first coefficient of thermal expansion that is matched to a second coefficient of thermal expansion of the lens within 10%.
12. 12 . The head-mounted device optical module of claim 10 , further comprising: epoxy that attaches the second portion to the peripheral edge.
13. 13 . The head-mounted device optical module of claim 10 , further comprising: epoxy that attaches the first portion to the support.
14. 14 . The head-mounted device optical module of claim 10 , further comprising: a screw that attaches the first portion to the support.
15. 15 . The head-mounted device optical module of claim 14 , further comprising: a ring-shaped seal between the support and the flexure.
16. 16 . The head-mounted device optical module of claim 10 , wherein the flexure has a U-shaped cross-sectional shape and comprises polymer.
17. 17 . The head-mounted device optical module of claim 16 , wherein the polymer has an elongation-to-failure value of at least 30%.
18. 18 . A head-mounted device, comprising: a head-mounted housing; and optical assemblies in the head-mounted housing that are configured to provide images to eye boxes, wherein each optical assembly includes: a display, a lens support coupled to the display, a lens, and a lens mount having multiple flexures, wherein each of the multiple flexures is coupled between the lens and the lens support at a different location along a peripheral edge of the lens.
19. 19 . The head-mounted device of claim 18 , wherein the lens support comprises a metal lens support having a tubular shape, and at least one flexure of the multiple flexures comprises a polymer ring with a U-shaped cross-sectional shape.
20. 20 . The head-mounted device of claim 18 , further comprising: elastomeric seals between the peripheral edge of the lens and the lens support.

Description

This application is a continuation of U.S. patent application Ser. No. 18/326,540, filed May 31, 2023, which claims the benefit of provisional patent application No. 63/431,394, filed Dec. 9, 2022, which are hereby incorporated by reference herein in their entireties. FIELD This relates generally to electronic devices, and, more particularly, to electronic devices such as head-mounted devices. BACKGROUND Electronic devices such as head-mounted devices have displays that generate images and lenses that are used in presenting the images to users. Components such as lenses may be sensitive to stress, which raises challenges when mounting lenses in head-mounted devices. SUMMARY A head-mounted device may include optical assemblies for presenting images to a user. The optical assemblies may each have a display for generating an image and a lens that presents the image to a corresponding eye box for viewing by a user. The lens may be a catadioptric lens with polymer lens elements that exhibit stress-induced birefringence when subjected to excessive stress. The optical assemblies may have lens barrels. Each lens barrel may have a first end to which a display is mounted and may have an opposing second end. A lens mount that helps reduce stress in the lens may be used to attach the lens to the second end of the lens barrel. The mount may have at least one flexure. The flexure may have a U-shaped cross-sectional shape. The mount may have a ring-shaped flexure that extends around a peripheral edge of the lens, may have flexure segments, or may have a set of three discrete flexures located at different positions along the edge of the lens. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram of an illustrative head-mounted device in accordance with an embodiment. FIG. 2 is a front view of an illustrative lens in accordance with embodiments. FIGS. 3 and 4 are cross-sectional side view of peripheral portions of illustrative lenses and associated mounting structures in accordance with embodiments. FIGS. 5 and 6 are top views of illustrative flexures for mounting a lens in accordance with embodiments. FIGS. 7, 8, 9, and 10 are cross-sectional side views of additional illustrative flexure arrangements for mounting a lens in accordance with embodiments. FIG. 11 is a diagram showing how adhesive may be introduced into a gap between an illustrative flexure and a lens in accordance with an embodiment. DETAILED DESCRIPTION Electronic devices such as head-mounted devices may have displays for displaying images and lenses that are used in presenting the images to eye boxes for viewing by a user. The lenses may be mounted in a head-mounted device using support structures that help minimize lens stress. In an illustrative embodiment, the lenses are mounted in rigid lens supports such as metal lens barrels using lens mounts based on flexures. The flexures help prevent stress from being applied to the lenses even when the electronic devices are subjected to changes in operating temperature that cause the lenses to expand and contract. FIG. 1 is a schematic diagram of an illustrative electronic device of the type that may include lenses mounted with flexures. Device 10 of FIG. 1 may be a head-mounted device (e.g., goggles, glasses, a helmet, and/or other head-mounted device. In an illustrative configuration, device 10 is a head-mounted device such as a pair of goggles (sometimes referred to as virtual reality goggles, mixed reality goggles, augmented reality glasses, etc.). As shown in the illustrative cross-sectional top view of device 10 of FIG. 1, device 10 may have a housing such as housing 12 (sometimes referred to as a head-mounted support structure, head-mounted housing, or head-mounted support). Housing 12 may include a front portion such as front portion 12F and a rear portion such as rear portion 12R. When device 10 is worn on the head of a user, rear portion 12R rests against the face of the user and helps block stray light from reaching the eyes of the user. Main portion 12M of housing 12 may be attached to head strap 12T. Head strap 12T may be used to help secure main portion 12 on the head and face of a user. Main portion 12M may have a rigid shell formed from housing walls of polymer, glass, metal, and/or other materials. When housing 12 is being worn on the head of a user, the front of housing 12 may face outwardly away from the user and the rear of housing 12 (and rear portion 12R) may face towards the user. In this configuration, rear portion 12R may face the user's eyes located in eye boxes 36. Device 10 may have electrical and optical components that are used in displaying images to eye boxes 36 when device 10 is being worn. These components may include left and right optical assemblies 20 (sometimes referred to as optical modules). Each optical assembly 20 may have an optical assembly support 38 (sometimes referred to as a lens barrel, optical module support, or support structure). Supports 38 may have hollow tubul