Light Guide with Localized Surface Roughness for Optical Shutter
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Solution Overview
Problem
Existing light guides for optical shutters and planar light-source devices face issues with transparency when the light source is off and concealment capability when the light source is on, due to roughened surfaces leading to low light intensity and directional control problems.
Innovation Solution
A plate-type light guide with specific surface features, including microscopic recesses or protrusions on main surfaces, where the haze value is 3% or lower and the maximum emission angle is optimized to ensure high transparency and efficient light utilization, allowing for excellent concealment when the light source is on.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the shutter region of the light guide is roughened to enable light diffusion, then the optical shutter can conceal the back side when the light source is on, but the transparency when the shutter is open is insufficient
Solution Approach 1:
The patent applies different surface treatments to different regions of the light guide: the shutter region has a roughened surface for light diffusion and concealment, while the non-shutter region maintains a smooth surface for high transparency. This local differentiation allows each region to optimize its function without compromising the other.
Solution Approach 2:
The light guide is divided into distinct functional regions: a shutter region with roughened surface and a non-shutter region with smooth surface. This segmentation enables independent optimization of optical properties in each region, resolving the contradiction between concealment and transparency.
2Object-affected harmful factors
If the entire light guide surface is roughened to diffuse light, then the optical shutter achieves concealment capability, but the light intensity in the front direction is low and directions of emitted light are hard to control
Solution Approach 1:
The patent applies different surface treatments to different regions of the light guide: the shutter region has a roughened surface for light diffusion and concealment, while the non-shutter region maintains a smooth surface for high transparency. This local differentiation allows each region to optimize its function without compromising the other.
3Object-affected harmful factors
If the light guide surface is roughened to enable light diffusion, then the optical shutter function is achieved, but the design features and transparency when the light source is off are compromised
Solution Approach 1:
The patent applies different surface treatments to different regions of the light guide: the shutter region has a roughened surface for light diffusion and concealment, while the non-shutter region maintains a smooth surface for high transparency. This local differentiation allows each region to optimize its function without compromising the other.
4Illumination intensity
If microscopic recesses or protrusions are formed on the light guide surface, then light emission direction and utilization efficiency are improved, but the manufacturing complexity increases
Solution Approach 1:
The patent replaces complex mechanical surface structuring with a chemical etching process using fluorinated compounds. This substitution achieves the desired microscopic recesses or protrusions for light direction control while simplifying the manufacturing process and reducing device complexity.
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 provides high transparency when the light source is off and effective concealment when on, enhancing the design and functionality of optical shutters and planar light-source devices by optimizing light emission patterns and utilization efficiency.
Implementation Method 1
a maximum emission angle, at which maximizes the intensity of emitted light, from a region of the main surface with the light emitting mechanism is in a range from −60 degrees to +60 degrees with respect to a normal line to the main surface
Implementation Method 2
the haze value is 3% or lower in the region where the light emitting mechanism is provided
Data Source
AI summary
Provided is a plate-type light guide (4) in which two opposing main surfaces are set as light emitting surfaces (6A, 6B) and at least one side-edge surface is set as a light incidence surface (5). In such a light guide, a light emitting mechanism (6) is provided in at least one region of at least one main surface; the haze value is 3% or lower in the region where the light emitting mechanism is provided; when a perfect diffuse light enters through at least one light incidence surface (5), a maximum emission angle (θA, θB), at which maximizes the intensity of emitted light (8) from the main surface is in a range from −60 degrees to +60 degrees with respect to a normal line to the main surface; and the utilization efficiency of emitted light is 15% or greater.