Eye Test Display Luminance Control for Accurate Refraction
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Solution Overview
Problem
Existing vision testing systems face inaccuracies due to non-linear adjustment of screen luminance to ambient luminance, leading to discrepancies between objectively and subjectively measured refractive values, especially under mesopic or scotopic lighting conditions.
Innovation Solution
A vision testing method using a backlit screen with an infrared light source and camera, where visual acuity symbols are adapted to objectively measured refractive values, and screen luminance is adjusted proportionally to ambient luminance, allowing for accurate subjective verification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If an optoelectronic sensor is used to adjust screen luminance to ambient luminance, then the screen luminance can be regulated, but the non-linear response of the sensor causes inaccurate refraction determination under changing lighting conditions
Solution Approach 1:
The patent changes the response characteristic parameter of the sensor from non-linear to linear by using a linear response sensor specifically designed for this application. This ensures that the screen luminance adjustment accurately reflects the ambient luminance changes, eliminating measurement errors in refraction determination.
Solution Approach 2:
The patent replaces the traditional optoelectronic sensor-based adjustment mechanism with a linear response sensor system that provides more accurate and proportional luminance adjustment. This substitution eliminates the non-linear response issue inherent in conventional sensors.
2Adaptability or versatility
If the room is darkened to simulate twilight or night vision conditions, then the desired lighting conditions are created, but the camera device cannot record the eyes accurately
Solution Approach 1:
The patent introduces an infrared light source as an intermediary that illuminates the subject's eyes without being detected by the camera device. This allows the room to be darkened for twilight/night vision simulation while the infrared light enables accurate eye recording through the camera device.
Solution Approach 2:
The patent applies local quality by using infrared illumination specifically for the eye recording function, separate from the visible light used for screen display and ambient lighting simulation. This localized infrared illumination enables eye detection without compromising the darkened room conditions.
3Difficulty of detecting and measuring
If infrared light is used to illuminate the eyes for recording, then eye recording is enabled under dark conditions, but the infrared light may cause dazzling to the subject
Solution Approach 1:
The patent applies local quality by positioning infrared light sources at specific locations (adjacent to the camera device or within the display device) and directing the infrared illumination only toward the subject's eyes from the camera side, minimizing scattered light that could cause dazzling while maintaining effective eye illumination for recording.
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
Enables faster and more accurate vision tests by minimizing glare and ensuring consistent display conditions, facilitating direct comparison of objectively and subjectively measured refractive values under varying lighting conditions.
Implementation Method 1
the display device having an illumination device with an infrared light source, by means of which the eyes of the test person can be illuminated
Implementation Method 2
the eyes of the subject can be recorded completely or partially in different spectra by means of the camera device
Implementation Method 3
the adjustment device can have a measuring device for measuring the screen luminance
Data Source
Figure 1~2
AI summary
The invention relates to an eye test system (10) and a method for checking the eyes of a test person, with a display device (11, 12, 13) with which at least one eye of the test person can be used to visualize eye test symbols, with a control unit (14) for controlling the display device , wherein the display device comprises a backlit screen (19, 30, 35), wherein the display device has a camera device (25) by means of which the subjects eyes can be recorded, wherein the display device has a lighting device (26) with an infrared light source (27), can be illuminated by the subjects eyes.