Light Control Sheet Driving for Stable Clarity and Haze Control
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Solution Overview
Problem
The value of haze in light control sheets changes significantly outside a predetermined voltage range, leading to discrepancies in object recognition due to varying degrees of scattering, which are not accounted for by existing technologies.
Innovation Solution
A light control device and method that selectively exhibits either a first characteristic where clarity changes more than haze per unit voltage or a second characteristic where haze changes more than clarity, using a drive circuit to control the light control sheet's state, ensuring consistent scattering properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If haze is used as the sole evaluation parameter for light control sheet transmittance, then manufacturing simplicity is maintained, but recognition consistency of objects through the light control sheet deteriorates due to unaccounted scattering variations
Solution Approach 1:
The light control sheet evaluation is segmented into two distinct parameters: haze (for diffuse transmittance) and clarity (for straight light transmittance). This segmentation allows each parameter to independently evaluate different aspects of light scattering, providing a more comprehensive and accurate assessment of the light control sheet's optical performance across different voltage ranges.
Solution Approach 2:
The invention adds a new evaluation dimension by introducing clarity measurement alongside the existing haze measurement. Clarity evaluates narrow-angle scattered light (within ±2.5°) while haze evaluates wide-angle scattered light, creating a two-dimensional evaluation system that captures the full spectrum of light scattering behavior and eliminates the limitations of single-parameter evaluation.
2Device complexity
If a single parameter (haze) is used to determine scattering degree, then measurement complexity is reduced, but scattering control precision deteriorates outside predetermined voltage range
Solution Approach 1:
The scattering evaluation is segmented into two distinct measurement systems: haze measurement for wide-angle scattered light and clarity measurement for narrow-angle scattered light. This segmentation enables precise control of scattering properties across different voltage ranges by selecting the appropriate parameter based on the operating conditions.
Solution Approach 2:
The invention changes the evaluation parameter from a single haze value to a dual parameter system (haze and clarity). This parameter change allows the system to adapt to different voltage ranges and scattering conditions, providing precise scattering control by selecting the dominant parameter according to the operating state.
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
This approach suppresses discrepancies in object recognition by precisely controlling scattering through clarity or haze, enhancing the device's performance and consistency across different voltage ranges.
Implementation Method 1
The light control layer contains, for example, a polymer network which contains a plurality of domains, and a liquid crystal composition which contains liquid crystal molecules and is filled in the polymer network. The drive circuit applies voltage between the pair of transparent electrodes. In the light control sheet, the transmittance of the light control layer changes as the orientation state of the liquid crystal molecules changes corresponding to a potential difference between the pair of transparent electrode layers.
Data Source
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AI summary
A light control sheet includes a first characteristic and a second characteristic which are selectively exhibited. In the first characteristic, an absolute value of a change in a value of clarity per unit voltage is greater than an absolute value of a change in a value of haze per unit voltage. In the second characteristic, an absolute value of a change in a value of haze per unit voltage is equal to or greater than an absolute value of a change in a value of clarity per unit voltage. Haze is calculated in accordance with JIS K 7136:2000. Clarity is calculated from the following Formula (1): 100×LC−LR/LC+LR where LC is an intensity of straight light travelling straight along a travelling direction of parallel light that has entered the light control sheet, among light that has passed through the light control sheet, and LR is an intensity of narrow-angle scattered light having an angle within ±2.5° relative to the travelling direction of the parallel light.