VR Eye-Tracking Optics Using Diffractive Light Pattern Calibration
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Solution Overview
Problem
Existing head-mounted virtual reality devices face issues of high calibration complexity and low calibration accuracy due to the use of multiple infrared emitting diodes, which lead to exposure of circuit boards, electrostatic interference, and increased assembly errors.
Innovation Solution
A head-mounted virtual reality device utilizing a light source and diffractive optical element to form a reflected pattern on the eyeball, reducing the number of light-emitting components and minimizing interference, with a processor determining pupil coordinates for improved calibration accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If multiple infrared emitting diodes are used for eye movement recognition, then the coverage area is improved, but the device complexity and assembly error increase
Solution Approach 1:
The patent segments the light emission function by using a diffractive optical element to divide a single light source into multiple light-emitting holes, each acting as an independent virtual light source. This segmentation achieves wide coverage area while avoiding the complexity of assembling multiple physical infrared emitting diodes.
Solution Approach 2:
The diffractive optical element serves as an intermediary between the single light source and the eye tracking system. It transforms one light source into multiple effective light-emitting points, enabling the system to achieve the coverage equivalent of multiple diodes without the associated assembly complexity and errors.
2Area of stationary object
If multiple infrared emitting diodes are arranged on the circuit board, then the light coverage is improved, but the circuit board size increases and exposure occurs
Solution Approach 1:
The patent merges the function of multiple infrared emitting diodes into a single light source combined with a diffractive optical element. This consolidation maintains the light coverage area while significantly reducing the circuit board area required, as only one light source needs to be mounted rather than multiple diodes.
Solution Approach 2:
The diffractive optical element creates multiple light-emitting holes in the optical path without requiring multiple physical diode mounting positions on the circuit board. This dimensional transformation in the optical domain allows wide coverage while keeping the circuit board footprint small.
3Area of stationary object
If multiple infrared emitting diodes are used, then the eye movement recognition coverage is improved, but the calibration accuracy decreases due to interference
Solution Approach 1:
The diffractive optical element segments the light from a single source into multiple spatially separated light-emitting holes. Each hole produces light rays that diverge at controlled small angles, reducing mutual interference while maintaining comprehensive eye movement coverage, thus improving calibration accuracy.
Solution Approach 2:
The patent changes the spatial distribution parameters of the light sources by using diffraction to create multiple holes with specific angular divergences. This parameter optimization ensures that light rays from different holes do not excessively overlap, reducing interference and improving the precision of eye movement calibration.
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 solution reduces the size of the circuit board, minimizes assembly errors, and enhances calibration accuracy by dispersing light into multiple rays through a diffractive optical element, improving eye movement recognition precision.
Implementation Method 1
the diffractive optical element which disperses the light source into a plurality of rays
Data Source
AI summary
The present disclosure provides a head-mounted virtual reality device, including an eye movement recognition assembly and a processor, where the eye movement recognition assembly includes a light source assembly and a first camera; the light source assembly includes a light source and an optical element, where the light source assembly is configured such that a first reflected pattern on an eyeball of a user is formed by light emitted by the light source assembly when the head-mounted virtual reality device is used; the first camera is configured to photograph a first eye picture of a user when the head-mounted virtual reality device is used, and the first eye picture includes at least part of the first reflected pattern; and the processor is configured to acquire the first eye picture photographed by the first camera, and process the first eye picture.