Scanning Waveguide Display for Compact Near-Eye Optics

Solution Overview

Problem

Conventional near-eye displays (NEDs) for virtual and augmented reality systems face challenges in achieving a compact and lightweight design while maintaining a large exit pupil, leading to bulky and heavy devices due to the need for large lenses.

Innovation Solution

A scanning waveguide display system that includes a light source, a source waveguide, and an output waveguide, where the light source emits image light based on scanning instructions, expanding it in at least one dimension and coupling it into the output waveguide to create a larger exit pupil, allowing for a more compact and lightweight design.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If conventional NEDs use large lenses to achieve a large exit pupil, then the exit pupil size is improved, but the device becomes bulky and heavy

Engineering Contradiction:

Improveexit pupil sizeVSAvoiddevice weight

Core Design Contradiction:

Area of stationary objectVSWeight of stationary object

Solution Approach 1:

The patent replaces conventional mechanical lens systems with a waveguide-based optical system. The waveguide display uses total internal reflection and optical coupling to expand the exit pupil without requiring large physical lenses, thereby reducing device weight while maintaining a large exit pupil area.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent transitions from a planar lens-based exit pupil expansion to a three-dimensional waveguide-based expansion. By using waveguides that can be configured in space, the system achieves exit pupil expansion in multiple dimensions without proportionally increasing the physical footprint or weight of the device.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Area of stationary object

If conventional NEDs use large lenses to achieve a large exit pupil, then the exit pupil size is improved, but the device becomes bulky

Engineering Contradiction:

Improveexit pupil sizeVSAvoiddevice volume

Core Design Contradiction:

Area of stationary objectVSVolume of moving object

Solution Approach 1:

The patent replaces conventional mechanical lens systems with a waveguide-based optical system. The waveguide display uses total internal reflection and optical coupling to expand the exit pupil without requiring large physical lenses, thereby reducing device weight while maintaining a large exit pupil area.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The waveguide structure allows for nested optical paths where light is guided through internal reflections within the waveguide material itself, eliminating the need for separate external lens components and reducing overall device volume.

Inventive Principle:

Principle #7Nested doll (Nesting)

3Ease of manufacture

If conventional NEDs use traditional display elements with lenses, then image projection is achieved, but the device complexity increases

Engineering Contradiction:

Improvedisplay functionalityVSAvoidoptical system complexity

Core Design Contradiction:

Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent replaces conventional mechanical lens systems with a waveguide-based optical system. The waveguide display uses total internal reflection and optical coupling to expand the exit pupil without requiring large physical lenses, thereby reducing device weight while maintaining a large exit pupil area.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The scanning waveguide display system effectively projects images directly into the user's eye, providing a large exit pupil and a wide field of view while minimizing the device's weight and size, enhancing user experience in virtual and augmented reality applications.

Implementation Method 1

The source waveguide expands the received image light in at least one dimension

Methodology Applied

Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 2

The output waveguide couples the received expanded image light emitted from the source waveguide at the input area

Methodology Applied

Scientific EffectOptical waveguide coupling: Waveguide (optics)

Data Source

PatentUS10527858B1Scanning waveguide display

Publication Date: 2020.01.07 META PLATFORMS TECHNOLOGIES LLC

AI summary

A waveguide display is used for presenting media to a user. The waveguide assembly includes a light source, a source waveguide, an output waveguide, and a controller. The light source emits image light based on scanning instructions from the controller. The source waveguide receives the image light from the light source, expands the image light in at least one dimension, and outputs an expanded image light to the output waveguide at an input area. The output waveguide outputs the expanded image light from a portion of an output area based on a direction of the expanded light from the source waveguide.