Spatially Varying Hologram Writing With Toric Wavefront Conditioning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing eye tracking systems in head-mounted displays (HMDs) are limited by natural obstructions such as eyelashes and eyelids, which degrade image quality and hinder effective eye tracking operations.
Innovation Solution
A system and method for conically recording spatially varying holograms using a hologram recording system with optical elements that condition wavefronts of writing beams, including mirrors and toric optical elements, to enable single-shot recording of holograms, allowing for improved eye tracking by reducing obstructions and enhancing image reception.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional eye tracking systems are used in HMDs, then the system structure is simple, but image quality is degraded due to obstructions from eyelashes and eyelids
Solution Approach 1:
The patent introduces a waveguide system with holographic optical elements as an intermediary between the eye and the imaging path. This waveguide mediates the light path to capture eye reflections without being blocked by natural obstructions, thereby maintaining image quality while adding optical complexity.
Solution Approach 2:
The patent transitions from direct line-of-sight eye tracking to a multi-dimensional optical path using waveguides and holographic elements. By adding spatial dimensions through optical routing, the system captures eye images from angles that bypass natural obstructions like eyelids and lashes.
2Measurement precision
If spatially varying holograms are recorded to improve eye tracking, then image reception is enhanced, but the recording process becomes more complex
Solution Approach 1:
The patent employs spatially varying holograms where different regions of the waveguide contain locally optimized grating structures. Each region is tailored to specific angular ranges and viewing conditions, enabling precise eye tracking measurements while managing recording complexity through localized optimization.
Solution Approach 2:
The patent varies multiple parameters in the holographic recording process including grating vector orientations, spatial frequencies, and exposure angles to create spatially varying structures. These parameter variations enable the waveguide to handle multiple light paths and improve eye tracking precision.
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 improved eye tracking in HMDs by reducing obstructions and enhancing image reception, thereby improving the accuracy and reliability of eye tracking operations.
Implementation Method 1
optical elements that condition wavefronts of writing beams
Implementation Method 2
Holography is the science related to recording light-operative structures on or in an optical medium
Implementation Method 3
including mirrors and toric optical elements
Implementation Method 4
toric optical elements
Data Source
AI summary
An apparatus, system, and method for a hologram recording system include a recording medium, a light source, and optical elements. The recording medium is configured to record a hologram. At least one light source is configured to provide a writing beam. The optical elements are positioned in a light path of the writing beam and are configured to condition the writing beam to record the hologram at least partially in the volume. The optical elements may include at least one toric optical element and a mirror. The toric optical element may be configured to subtract a quadratic phase from a wavefront of the writing beam, and the mirror may be configured to subtract a linear phase from the wavefront of the writing beam.