Gaze-Contingent Imaging System with Variable Focal Length Optical Element

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Solution Overview

Problem

Conventional imaging systems for extended reality (XR) devices have low autofocus speed, leading to time-consuming image generation and suboptimal warped images, as they employ uniform optical components that struggle to accommodate the wide field of view and angular resolution of the human visual system.

Innovation Solution

An imaging system with a camera and an optical element comprising different focal lengths, where a processor adjusts the optical focus based on the user's gaze direction to capture warped images with spatially-uniform angular resolution, utilizing a combination of physical and processing-based adjustments for high-speed autofocus.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional uniform optical components are used, then the imaging system can be manufactured with standard components, but the system cannot accommodate the wide field of view and angular resolution requirements of the human visual system

Engineering Contradiction:
Improvefield of view and angular resolutionVSAvoidcomponent availability
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent applies local quality by using variable optical power components that provide different optical properties in different regions of the field of view. The optical element has spatially varying focal lengths, allowing the periphery to capture wider angles while the center maintains high angular resolution, matching human visual system characteristics without requiring unavailable uniform components for the entire field.

Inventive Principle:
Principle #3Local quality

2Speed

If conventional autofocusing mechanism is used, then the system can adjust optical focus, but the autofocus speed is low and image generation is time-consuming

Engineering Contradiction:
Improveautofocus speedVSAvoidimage generation time
Core Design Contradiction:
SpeedVSLoss of time

Solution Approach 1:

The patent replaces conventional mechanical autofocusing mechanisms with a combination of physical optical adjustments and processing-based focus refinement. The variable optical power component enables faster physical focus adjustment, while computational methods provide rapid focus optimization, eliminating the slow iterative mechanical adjustment process of traditional autofocus systems.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Speed

If autofocus speed is increased using conventional techniques, then the autofocus response is faster, but the generated warped images appear blurred

Engineering Contradiction:
Improveautofocus speedVSAvoidimage quality
Core Design Contradiction:
SpeedVSManufacturing precision

Solution Approach 1:

The patent introduces an intermediary processing stage between the variable optical power component and the final image output. The processing-based focus adjustment acts as an intermediary that refines the rapidly captured images, correcting any blurring artifacts while preserving the high-speed capture capability. This intermediary computational step ensures both speed and image quality.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Adaptability or versatility

If specialized optical components with variable optical properties are used, then the system can capture warped images with wide field of view, but the device complexity increases

Engineering Contradiction:
Improvefield of viewVSAvoidoptical component complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the optical system into multiple functional components: a variable optical power element for field of view control, separate processing modules for focus adjustment and image warping. This segmentation allows each component to be optimized independently and simplifies the overall system architecture compared to a single complex uniform optical component attempting to handle all functions simultaneously.

Inventive Principle:
Principle #1Segmentation

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 system enables real-time or near-real-time generation of high-quality, gaze-contingent warped images with spatially-variable angular resolution, enhancing user immersion in XR environments by efficiently utilizing gaze direction information for focus adjustment.

Implementation Method 1

an optical element that comprises at least a first optical portion and a second optical portion having different focal lengths

Methodology Applied
Scientific EffectRefraction: Refraction

Data Source

PatentUS11509835B2Imaging system and method for producing images using means for adjusting optical focus
Publication Date: 2022.11.22 VARJO TECH OY
  • US11509835B2 patent drawing
  • US11509835B2 patent drawing
  • US11509835B2 patent drawing

AI summary

An imaging system for producing images for display apparatus. Imaging system includes at least one imaging unit arranged to face real-world scene including camera, optical element including first optical portion and second optical portion having different focal lengths, first focal length of first optical portion is smaller than second focal length of second optical portion, and means for adjusting optical focus; and processor. Processor is configured to obtain gaze direction of user; determine region of interest within real-world scene; and control means for adjusting optical focus of imaging unit, based on focal lengths of first and second optical portions, to capture warped image of real-world scene, the warped image having spatially-uniform angular resolution.