Magic Leap Patent | Method and system for integration of refractive optics with a diffractive eyepiece waveguide display

Patent: Method and system for integration of refractive optics with a diffractive eyepiece waveguide display

Publication Number: 20250208331

Publication Date: 2025-06-26

Assignee: Magic Leap

Abstract

A method of fabricating an optical element includes providing a substrate, forming a castable material coupled to the substrate, and casting the castable material using a mold. The method also includes curing the castable material and removing the mold. The optical element includes a planar region and a clear aperture adjacent the planar region and characterized by an optical power.

Claims

What is claimed is:

1. A method of fabricating an optical element, the method comprising:providing a substrate;forming a castable material coupled to the substrate;casting the castable material using a mold;curing the castable material; andremoving the mold;wherein the optical element comprises a planar region and a clear aperture adjacent the planar region and characterized by an optical power.

2. The method of claim 1 wherein the substrate comprises a cover glass.

3. The method of claim 2 wherein the cover glass is planar.

4. The method of claim 1 wherein the substrate comprises a planar polymer structure.

5. The method of claim 1 wherein the castable material comprises a UV cured resin.

6. The method of claim 1 wherein the mold comprises an anti-stiction coating.

7. The method of claim 6 wherein the anti-stiction coating is hydrophobic.

8. The method of claim 6 wherein the anti-stiction coating comprises silicon oxide or silicon nitride.

9. The method of claim 1 wherein casting the castable material comprises forming nano-features in the castable material.

10. The method of claim 9 wherein the nano-features are diffractive features configured to reduce reflection at an interface of the castable material.

1. 1. A viewing optics assembly including a viewing area, the viewing optics assembly comprising:a first cover plate including a first region having a first optical power and a first planar region laterally adjacent to the first region and positioned outside the viewing area;a waveguide having a world side and a user side; anda second cover plate having a second optical power, wherein the first optical power and second optical power have different values with respect to each other;wherein the waveguide is disposed between the first cover plate and the second cover plate.

12. The viewing optics assembly of claim 11 wherein:the first cover plate is disposed adjacent the world side of the waveguide; andthe second cover plate is disposed adjacent the user side of the waveguide.

13. The viewing optics assembly of claim 11 wherein the first optical power is positive and the second optical power is negative.

14. The viewing optics assembly of claim 11 wherein the first optical power and an absolute value of the second optical power are equal.

15. The viewing optics assembly of claim 11 wherein the first region of the first cover plate comprises nano-features.

16. The viewing optics assembly of claim 15 wherein the nano-features comprise an anti-reflection structure.

17. The viewing optics assembly of claim 11 wherein the second cover plate includes a second region having the second optical power, wherein the second region comprises nano-features.

18. The viewing optics assembly of claim 11 wherein the second cover plate comprises a second region having the second optical power and a second planar region laterally 2 adjacent to the second region, wherein the second region is positioned outside the viewing area.

19. The viewing optics assembly of claim 11 wherein:the first cover plate is separated from the world side of the waveguide by a first distance; andthe second cover plate is separated from the user side of the waveguide by a second distance.

20. The viewing optics assembly of claim 11 wherein:the second cover plate is configured to diverge light rays generated by the waveguide; andthe first cover plate is configured to compensate for the second optical power of the second cover plate.

Description

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No. 18/513,308, filed on Nov. 17, 2023, entitled “METHOD AND SYSTEM FOR INTEGRATION OF REFRACTIVE OPTICS WITH A DIFFRACTIVE EYEPIECE WAVEGUIDE DISPLAY,” which is a divisional of U.S. patent application Ser. No. 17/320,060, filed on May 13, 2021, U.S. Pat. No. 11,994,706, issued on May 28, 2024, entitled “METHOD AND SYSTEM FOR INTEGRATION OF REFRACTIVE OPTICS WITH A DIFFRACTIVE EYEPIECE WAVEGUIDE DISPLAY,” which is a non-provisional of and claims the benefit of and priority to U.S. Provisional Patent Application No. 63/025,069, filed on May 14, 2020, entitled “METHOD AND SYSTEM FOR INTEGRATION OF REFRACTIVE OPTICS WITH A DIFFRACTIVE EYEPIECE WAVEGUIDE DISPLAY,” which are hereby incorporated by reference in their entirety for all purposes.

BACKGROUND OF THE INVENTION

Modern computing and display technologies have facilitated the development of systems for so called “virtual reality” or “augmented reality” experiences, wherein digitally reproduced images or portions thereof are presented to a viewer in a manner wherein they seem to be, or may be perceived as, real. A virtual reality, or “VR,” scenario typically involves presentation of digital or virtual image information without transparency to other actual real-world visual input; an augmented reality, or “AR,” scenario typically involves presentation of digital or virtual image information as an augmentation to visualization of the actual world around the viewer.

Despite the progress made in these display technologies, there is a need in the art for improved methods and systems related to augmented reality systems, particularly, display systems.

SUMMARY OF THE INVENTION

The present invention relates generally to methods and systems for waveguide displays. More particularly, embodiments of the present invention provide methods and systems that integrate refractive optics with a diffractive eyepiece waveguide display, also referred to as a waveguide display. The invention is applicable to a variety of applications in computer vision and image display systems.

As described herein, embodiments of the present invention relate to methods and systems for fabricating laminated lenses and optical elements having optical power, which can be utilized with diffractive eyepiece waveguides forming part of an augmented reality display device. As described herein, methods of lens integration with a waveguide optical combiner for mixed reality displays are provided. In a particular embodiment, a pair of lenses are utilized to create a virtual image depth plane, while preserving the depth planes of real world objects. The pair of lenses is integrated with waveguide layers to provide very thin and compact wearable form-factors and to improve user experience, including high optical transmission, by reducing the distance between the lenses in the pair of lenses while compensating the lens effect for the world view.

According to an embodiment of the present invention, a method of fabricating an optical element is provided. The method includes providing a substrate, forming a castable material coupled to the substrate, and casting the castable material using a mold. The method also includes curing the castable material and removing the mold.

According to another embodiment of the present invention, a method of fabricating an optical element is provided. The method includes providing a mold set having mold plates and placing a moldable material between the mold plates. The method also includes joining the mold plates, curing the moldable material to form the optical element, and removing the optical element from the mold set.

The optical element can be characterized by a negative optical power or a positive optical power. One of the mold plates can be characterized by a planar surface. The moldable material can be a UV curable resin. Moreover, at least one of the mold plates can include nano-features. In an embodiment, the optical element comprises a planar region and a clear aperture adjacent the planar region and characterized by an optical power. In some embodiments, the mold comprises an anti-stiction coating that can be hydrophobic. As an example, the anti-stiction coating can include silicon oxide or silicon nitride.

According to a specific embodiment of the present invention, an eyepiece waveguide is provided. The eyepiece waveguide includes a set of waveguide layers having a world side and a user side. The eyepiece waveguide also includes a first cover plate having a first optical power and disposed adjacent the world side of the set of waveguide layers and a second cover plate having a second optical power and disposed adjacent the user side of the set of waveguides.

Numerous benefits are achieved by way of the present invention over conventional techniques. For example, embodiments of the present invention provide methods and systems that provide compact eyepiece waveguide systems with integrated laminated lenses or optical elements that function as both a cover plate and a lens. Moreover, because embodiments of the present invention enable the pair of lenses that is integrated with the eyepiece waveguide to be positioned close to each other, optical aberrations are reduced in comparison with conventional techniques. These and other embodiments of the invention, along with many of its advantages and features, are described in more detail in conjunction with the text below and attached figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a simplified cross-sectional diagram illustrating a viewing optics assembly including an eyepiece waveguide and a laminated lens pair according to an embodiment of the present invention.

FIG. 1B is a simplified cross-sectional diagram illustrating a viewing optics assembly including an eyepiece waveguide and a set of cover plates with optical power according to an embodiment of the present invention.

FIGS. 2A-2C are simplified cross-sectional diagrams illustrating a process for fabricating a laminated lens according to an embodiment of the present invention.

FIG. 2D is a simplified cross-sectional diagram illustrating a process for fabricating a laminated lens according to another embodiment of the present invention.

FIGS. 3A-3D are simplified cross-sectional diagrams illustrating a process for fabricating a laminated lens using a master according to an embodiment of the present invention.

FIG. 4 is a simplified cross-section diagram of a laminated lens according to an embodiment of the present invention.

FIG. 5 is a simplified plan view of a laminated lens overlying elements of an eyepiece waveguide according to an embodiment of the present invention.

FIG. 6A-6C are simplified cross-sectional diagrams illustrating a process for fabricating a laminated lens with positive optical power according to an embodiment of the present invention.

FIG. 7A-7C are simplified cross-sectional diagrams illustrating a process for fabricating a laminated lens with positive optical power according to another embodiment of the present invention.

FIG. 8 is a simplified perspective view of a system for forming a plurality of laminated lenses according to an embodiment of the present invention.

FIGS. 9A-9D are simplified cross-sectional diagrams illustrating a process for fabricating an optical element according to an embodiment of the present invention.

FIG. 10 is a simplified cross-sectional diagram illustrating a mold with an anti-stiction coating according to an embodiment of the present invention.

FIG. 11A is a simplified cross-sectional diagram illustrating an optical element with nano-features fabricated on a planar side of the optical element according to an embodiment of the present invention.

FIG. 11B is a simplified cross-sectional diagram illustrating an optical element with nano-features fabricated on a curved side of the optical element according to an embodiment of the present invention.

FIG. 11C is a simplified cross-sectional diagram illustrating an optical element with nano-features fabricated on both the planar side and the curved side of the optical element according to an embodiment of the present invention.

FIG. 12 is a simplified cross-sectional diagram illustrating a VOA including an eyepiece waveguide and a set of optical elements according to an embodiment of the present invention.

FIG. 13A is a simplified cross-sectional diagram illustrating a bi-convex laminated lens according to an embodiment of the present invention.

FIG. 13B is a simplified cross-sectional diagram illustrating a convex meniscus lens according to an embodiment of the present invention.

FIG. 13C is a simplified cross-sectional diagram illustrating an achromatic laminated lens according to an embodiment of the present invention.

FIG. 13D is a simplified cross-sectional diagram illustrating an apochromatic laminated lens according to an embodiment of the present invention.

FIG. 14A is a simplified perspective diagram illustrating a first mold according to an embodiment of the present invention.

FIG. 14B is a simplified perspective diagram illustrating a first molding according to an embodiment of the present invention.

FIG. 14C is a simplified side view of a portion of a molding before and after a release layer coating process according to an embodiment of the present invention.

FIG. 14D is a perspective diagram illustrating a coated first molding according to an embodiment of the present invention.

FIG. 14E is a simplified perspective diagram illustrating a second molding according to an embodiment of the present invention.

FIG. 14F is a perspective diagram illustrating a coated second molding according to an embodiment of the present invention.