Electrophoretic Light Distribution Control for Dynamic Viewing Angle
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Solution Overview
Problem
Existing display devices lack a reliable mechanism to dynamically control the viewing angle, either limiting it to a narrow range to prevent peeking or expanding it for shared viewing, without compromising on brightness and uniformity.
Innovation Solution
A light distribution control element comprising transparent substrates, control electrodes, and electrophoretic elements with charged particles that change light blocking properties based on potential differences, allowing for adjustable viewing angles by controlling the dispersion of electrophoretic particles between transparent and light-blocking regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If electrophoretic particles are dispersed throughout the electrophoretic element to achieve wide viewing angle, then light blocking property is reduced, but brightness uniformity deteriorates due to non-uniform dispersion
Solution Approach 1:
The electrophoretic element is divided into multiple sub-regions with different particle concentrations. The control electrode patterns create distinct zones where particles accumulate to different degrees, segmenting the light blocking function across multiple concentration levels rather than using uniform dispersion throughout the entire element.
Solution Approach 2:
Different regions of the electrophoretic element are given different local qualities in terms of particle concentration. By controlling the electrode potential distribution, specific areas have higher particle density for light blocking while other areas maintain lower density for light transmission, creating spatially varying optical properties that simultaneously achieve wide viewing angle and uniform brightness.
2Object-affected harmful factors
If electrophoretic particles are concentrated in specific regions to block light, then viewing angle is narrowed for privacy, but optical transmittance is reduced
Solution Approach 1:
The system dynamically adjusts particle concentration distribution by changing electrode potential in real-time. When privacy mode is activated, particles are electrostatically concentrated in specific regions to block light from certain directions. When normal mode is activated, particles are redistributed to maintain high optical transmittance. This dynamic reconfiguration allows the same device to provide both privacy protection and high transparency as needed.
Solution Approach 2:
The optical transmittance and light blocking properties are controlled by changing the electrical parameter (potential difference) applied to the control electrodes. By adjusting the magnitude and distribution of the applied voltage, the particle concentration in different regions changes, thereby transitioning the element between transparent and light-blocking states without physical reconfiguration.
3Adaptability or versatility
If multiple control electrodes overlap with electrophoretic elements to enable independent region control, then viewing angle adjustment flexibility is improved, but device complexity increases
Solution Approach 1:
Multiple control electrode patterns are merged into a single integrated electrode structure that can generate multiple independent control regions. Instead of using separate electrodes for each controllable area, the invention combines several electrode patterns on the same substrate, where each pattern corresponds to a different controllable region of the electrophoretic element, reducing the number of separate components while maintaining independent control capability.
Solution Approach 2:
The control electrode structure is designed with multi-functionality to perform multiple control tasks simultaneously. A single electrode pattern can serve to control different regions for different viewing angle requirements, and the same electrode structure can be reconfigured through potential control to achieve various light distribution patterns, making the device versatile without proportionally increasing component count.
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 seamless switching between narrow and wide viewing angles, maintaining high optical transmittance and preventing non-uniformity in brightness, thus enhancing user experience in various display scenarios.
Implementation Method 1
dispersion of the electrophoretic particles changes depending on potential difference between the plurality of first control electrodes and the plurality of second control electrodes to change a range of outgoing direction of light transmitted through the light distribution control element
Data Source
AI summary
A light distribution control element includes a first transparent substrate, a second transparent substrate, first control electrodes and second control electrodes provided on the first transparent substrate, light-transmissive regions provided between the first transparent substrate and the second transparent substrate, and electrophoretic elements including electrophoretic particles charged to a specific polarity and having a light blocking property and optically transmissive dispersant. Each electrophoretic element is provided between two light-transmissive regions. At least a part of at least one of the first control electrodes and at least a part of at least one of the second control electrodes both overlap with each of the plurality of electrophoretic elements. Dispersion of the electrophoretic particles changes depending on potential difference between the first control electrodes and the second control electrodes to change a range of outgoing direction of light transmitted through the light distribution control element.