Smart Glasses Eye Tracking With Adaptive Fill-Light Wavelengths
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing eye tracking apparatuses in smart glasses suffer from image quality degradation and increased power consumption due to sunlight interference when used outdoors, leading to potential harm to human eyes.
Innovation Solution
An eye tracking apparatus that emits fill light rays with different central wavelengths based on ambient light intensity, minimizing sunlight interference by using fill light rays with solar spectral irradiance below a threshold, and employing dual-wavelength fill light sources to adapt to indoor and outdoor conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the power of the fill light lamp is increased to improve image quality under sunlight interference, then the image quality improves, but power consumption increases and harm to human eyes increases
Solution Approach 1:
The patent changes the wavelength parameter of the fill light from conventional 850nm or 940nm to 1064nm, where solar spectral irradiance is at a minimum. This parameter change allows the system to maintain good image quality without increasing power, as the 1064nm wavelength experiences minimal sunlight interference
Solution Approach 2:
The patent converts the harmful effect of sunlight interference into a beneficial selection criterion by choosing a wavelength (1064nm) where solar spectral irradiance is minimal. This transforms the problem of sunlight interference into an advantage by selecting a wavelength band where natural sunlight is weakest
2Measurement precision
If the power of the fill light lamp is increased to improve image quality under sunlight interference, then the image quality improves, but harm to human eyes increases leading to visual fatigue and even cataracts and retinal burns
Solution Approach 1:
The patent changes the wavelength parameter to 1064nm, which is at the minimum point of solar spectral irradiance. This parameter change simultaneously improves image quality by reducing sunlight interference and reduces harm to human eyes by avoiding high-power emission in the problematic 850nm-940nm ranges
Solution Approach 2:
The patent uses the natural minimum in solar spectral irradiance at 1064nm to simultaneously solve both image quality and eye safety problems, converting the environmental condition into a dual benefit
3Device complexity
If a single wavelength fill light is used, then the device complexity is low, but adaptability to different ambient light conditions is poor
Solution Approach 1:
The patent implements a dynamic wavelength selection system with multiple fill light sources (850nm, 940nm, 1064nm) that can adaptively switch between different wavelengths based on ambient light conditions, particularly sunlight intensity, thereby improving adaptability while managing device complexity
Solution Approach 2:
The patent makes the fill light system multi-functional by incorporating multiple wavelength sources that can operate in different scenarios: 850nm for low ambient light, 940nm for moderate conditions, and 1064nm for high sunlight interference, allowing one system to handle diverse lighting environments
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
Improves pupil image quality with a high signal-to-noise ratio while reducing power consumption and minimizing harm to human eyes by adapting to varying light conditions.
Implementation Method 1
the selected fill light lamp is a light-emitting diode (LED), where the central wavelength of the fill light lamp is usually 850 nm or 940 nm
Implementation Method 2
The blinking point is generated by reflecting light rays entering the pupil on the outer surface of the cornea
Implementation Method 3
A pupil image accompanying the reflection is captured by a camera sensitive to infrared spectrum
Data Source
AI summary
An eye tracking apparatus and smart glasses are provided. The eye tracking apparatus includes a fill light source, configured to emit to human eyes a first fill light ray with a first predetermined central wavelength or a second fill light ray with a second predetermined central wavelength based on ambient light intensity of the human eyes, solar spectral irradiance corresponding to the first and the second predetermined central wavelengths is less than a predetermined threshold, and a band range of the first fill light ray is different from a band range of the second fill light ray; a camera, configured to acquire a pupil image formed when the first or the second fill light ray irradiates the human eyes; and a processor, configured to determine movement of the human eyes based on the pupil image.