Micro-LED Pixel Refraction Structure for Asymmetric Viewing Angles
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Solution Overview
Problem
LEDs used in displays, such as automotive head-up displays, emit light uniformly in all directions, obstructing the driver's view and compromising safety due to wide-angle projection on the windshield.
Innovation Solution
A display device design featuring an anisotropic groove in pixel components with varying refractive materials, including a reflective material and two refractive materials with different indices, creating asymmetrical light emission to achieve a narrow viewing angle in specific directions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If LED emits light uniformly in all directions, then the display achieves high brightness and uniform illumination, but the light obstructs the driver's view and affects driving safety
Solution Approach 1:
The patent applies asymmetry by designing an anisotropic groove structure in the reflective material and using two refractive materials with different refractive indices arranged asymmetrically. This creates asymmetrical light emission where light is concentrated in specific directions (parallel and perpendicular to the groove central axis) while minimizing light emission in other directions, thereby reducing obstruction to the driver's view while maintaining display brightness
Solution Approach 2:
The patent implements local quality by creating regions with different optical properties within the pixel component. The anisotropic groove structure and the two refractive materials with different refractive indices (difference value 0.3 to 0.6) create localized areas that selectively guide and refract light in specific directions, allowing different parts of the light emission pattern to have different characteristics
2Adaptability or versatility
If the viewing angle is widened to improve visibility, then more users can view the display, but the light emission obstructs the front view and compromises safety
Solution Approach 1:
The patent resolves this contradiction by implementing asymmetrical light emission through the anisotropic groove and dual refractive material structure. The light emission is concentrated in specific angular ranges defined by the groove orientation and refractive index differences, creating a viewing pattern that provides adequate viewing angles for intended users while directing light away from the driver's line of sight, thus maintaining safety
3Device complexity
If a single refractive material is used to simplify the structure, then the device complexity is reduced, but the light emission remains symmetrical and obstructs the driver's view
Solution Approach 1:
The patent applies local quality by introducing a second refractive material with a different refractive index (difference value 0.3 to 0.6) in specific regions of the pixel component. This localized variation in refractive properties creates the asymmetrical light emission pattern needed to control viewing angles and reduce driver obstruction, while the overall structure remains relatively simple with the groove-based design
Solution Approach 2:
The patent uses composite materials by combining two refractive materials with different refractive indices within the same pixel component structure. This composite approach enables the asymmetrical light emission characteristics required to solve the driving safety issue while maintaining a compact and integrated design
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 asymmetrical light emission design enhances driving safety by preventing interference with the driver's view while maintaining necessary display functions, applicable in automotive head-up displays and other devices requiring narrow viewing angles for privacy or anti-peeping purposes.
Implementation Method 1
a refractive index of the second refractive material is greater than a refractive index of the first refractive material, and a difference value the refractive index of the first refractive material and the refractive index of the second refractive material is 0.3 to 0.6. Light emission of the display device in the first direction and in a second direction perpendicular to the first direction is asymmetrical.
Data Source
AI summary
A display device includes a display substrate and a transparent cover. The display substrate includes a plurality of pixel components arranged in an array. Each pixel component includes a micro light-emitting diode (LED), a reflective material, a first refractive material and a second refractive material. The reflective material is provided with a groove. An upper surface of the micro LED is exposed in the groove. The first refractive material is located in the groove and covers the upper surface of the micro LED. The second refractive material is located in the groove and covers the first refractive material. An interface between the first and second refractive materials is a curved surface. The transparent cover covers the display substrate. A third refractive region is formed between the transparent cover and the second refractive material. Light emission of the display device in a first direction and in a second direction is asymmetrical.