Reflective Element Head-Mounted Display for Augmented Reality

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Solution Overview

Problem

Existing head-mountable display (HMD) technologies either obscure the real-world environment or require complex waveguide arrangements to superimpose virtual images on the real world, lacking in flexibility and user experience for casual applications like gaming and domestic computing.

Innovation Solution

A head-mountable display system using a reflective element, such as a concave mirror, to reflect images from a mobile device's screen, allowing a magnified virtual image to be seen at infinity, enabling both augmented reality and obscured display modes with adjustable transparency and distortion compensation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a waveguide arrangement employing total internal reflection is used to superimpose displayed image on real-world view, then the user can see both virtual image and real world, but the device complexity increases

Engineering Contradiction:
Improveaugmented reality capabilityVSAvoidwaveguide arrangement
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent extracts the waveguide component from the system and replaces it with a simpler reflective element (such as a partially reflective mirror) positioned in front of the display device. This allows the displayed image to be superimposed on the real-world view without requiring complex waveguide optics, thereby reducing device complexity while maintaining augmented reality functionality.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of using complex waveguide arrangements to create virtual images, the patent uses a reflective element to create a reflected copy of the displayed image that is superimposed on the real-world view. This simpler optical copying mechanism achieves the same augmented reality effect with reduced complexity.

Inventive Principle:
Principle #26Copying

2Measurement precision

If display devices are positioned directly in front of user's eyes with obscuring lenses, then the user can see displayed images clearly, but the real-world environment is obscured

Engineering Contradiction:
Improvedisplay image clarityVSAvoidreal-world visibility
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent employs a reflective element with adjustable reflectivity (such as a partially reflective mirror or electrochromic mirror) that can dynamically switch between transparent and reflective states. This allows the system to adapt between providing clear display images (when reflective) and maintaining real-world visibility (when transparent), thereby resolving the contradiction between display clarity and environmental awareness.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The reflectivity parameter of the reflective element is changed to control the balance between display visibility and real-world visibility. By adjusting the reflectivity parameter, the system can transition between different operating modes: fully transparent for real-world viewing, partially reflective for augmented reality, and fully reflective for immersive display, thus resolving the contradiction.

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If the displayed image is magnified to appear at infinity, then the user experience is enhanced, but distortion compensation is required

Engineering Contradiction:
Improveuser experienceVSAvoiddistortion compensation
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent applies distortion compensation in advance during the image processing stage, before the image is displayed. By pre-distorting the image in the opposite direction of the expected optical distortion from the reflective element, the system ensures that the final perceived image is undistorted, thereby enhancing user experience without requiring complex real-time correction mechanisms.

Inventive Principle:
Principle #10Preliminary action

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

Enhances user experience by providing a flexible, magnified virtual display that can be seen at infinity, allowing for both augmented reality and virtual reality applications without obstructing the real world, while supporting eye-tracking and interaction features.

Implementation Method 1

a reflective element visible to an eye of the user and configured to reflect light incident upon the reflective surface so as to form a reflected image

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 2

a waveguide arrangement employing total internal reflection is used to convey a displayed image from a display device disposed to the side of the user's head

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Data Source

PatentEP2883101B1Head mountable device with holder for mobile device
Publication Date: 2019.11.20 SONY COMP ENTERTAINMENT EURO LTD
  • EP2883101B1 patent drawingFigure 1A~1B
  • EP2883101B1 patent drawingFigure 2A~2B
  • EP2883101B1 patent drawingFigure 3

AI summary

A head-mountable display device comprises a frame (30) to be mounted onto a user's head, the frame defining an eye display position which, in use, is positioned in front of an eye of the user;a reflective element (40) mounted with respect to the eye display position, the reflective element comprising a reflective surface which, in use, is visible to the eye (80) of the user; and a mobile device holder (50) configured to hold a mobile device (60) at a location and orientation on the frame; wherein : the reflective surface is configured to reflect light incident upon the reflective surface so as to form a reflected image; and the location and orientation in which the mobile device is held relative to a location and orientation of the reflective surface are such that, in use, light I arriving from a screen (62) of the mobile device held in the mobile device holder is reflected by the reflective surface so that a reflected image of at least a portion of the screen is visible to the user.