Curved, slim, see-through light guide with large eyebox

The curved light guide with a thicker in-coupler and angled out-coupler, along with low-reflection coatings and polarization techniques, addresses the small eyebox and stray light issues in eyewear displays, achieving improved image clarity and user accommodation.

JP7884064B2Active Publication Date: 2026-07-02GOOGLE LLC
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Patent Information

Application Number
JP2024526926
Authority / Receiving Office
JP · JP
Patent Type
Patents
Current Assignee / Owner
Priority Date
2021-11-09
Filing Date
2022-11-04
Publication Date
2026-07-02
Estimated Expiration
2042-11-04

AI Technical Summary

Technical Problem

Conventional eyewear display devices suffer from a small eyebox that does not accommodate diverse facial shapes, leading to reduced image visibility and increased stray light, which causes blurs and ghost images, and are constrained by optical efficiency and manufacturing limitations.

Method used

A curved light guide with a thicker in-coupler and angled out-coupler, combined with low-reflection coatings and polarization techniques, to enhance light coupling and reduce artifacts, allowing for an enlarged eyebox and improved image clarity.

Benefits of technology

The solution enlarges the eyebox to accommodate a wider range of facial shapes and reduces stray light, enhancing user experience by minimizing blurs and ghost images while maintaining high optical efficiency.

✦ Generated by Eureka AI based on patent content.

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Abstract

The display system includes a microdisplay and a curved light guide that expands light from the microdisplay toward the user's eye. The display system includes an in-coupler that is thicker than the curved light guide to couple light from the microdisplay into the curved light guide, and an out-coupler tilted at an angle to couple the display light out of the curved light guide after two bounces of the display light, resulting in a large eyebox. In some embodiments, the curved light guide includes a low-reflection coating on the world-facing surface with a gap through which the side image light escapes, and a sunglass coating on the lens that absorbs the side image light. The curved light guide includes a half-wave plate (HWP) to flip the input polarization of the main image to the orthogonal polarization, and a dielectric mirror that acts as a weak analyzer to darken the side image.
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Citation Information

Patent Citations

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    CN108152955A

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    JP2005084522A

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