Light Modulating Element for Variable ND Filters
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Solution Overview
Problem
Conventional variable ND filters face challenges in achieving high wavelength flatness and suppressing light source influence on color reproducibility due to limitations in controlling absorption wavelengths of multiple compounds, making it difficult to maintain consistent light attenuation across different light sources.
Innovation Solution
A light modulating element comprising multiple compounds with varying absorption wavelengths, where the concentration ratios are optimized to minimize the ratio between reference and contrast light sources in detection signal ratios, thereby reducing light source influence on color reproducibility, and using electrochromic compounds to achieve variable transmittance and light attenuation states.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple compounds with different absorption wavelengths are combined in a variable ND filter, then the degree of light attenuation can be electrically controlled, but it becomes difficult to achieve high wavelength flatness and suppress light source influence on color reproducibility
Solution Approach 1:
The patent applies parameter changes by systematically varying the concentration ratios of multiple electrochromic compounds (specifically compounds A, B, and C with different absorption characteristics) to optimize the variable transmittance spectrum. By adjusting these concentration parameters, the invention achieves both high wavelength flatness (TF ≤ 1.05) and suppressed light source influence (NWDMax ≤ 1.03), resolving the contradiction between electrical controllability and spectral uniformity.
Solution Approach 2:
The invention uses composite materials by combining multiple electrochromic compounds (A, B, and C) with different absorption wavelengths into a single light modulating element. This composite approach enables the system to achieve both variable light attenuation control and high wavelength flatness simultaneously, as the combined absorption spectra of the compounds create a more uniform overall transmission characteristic across the visible range.
2Manufacturing precision
If conventional ND filters use a multilayer film with high wavelength flatness, then light source influence on color reproducibility is reduced, but the degree of light attenuation becomes fixed and cannot be changed
Solution Approach 1:
The patent applies dynamics by using electrochromic compounds that can change their light absorption properties in response to electrical stimulation. The light modulating element transitions from a static, fixed attenuation state to a dynamic, variable attenuation state while maintaining high wavelength flatness. The electrochromic compounds' ability to reversibly change transmittance upon application of voltage enables both adaptability and spectral uniformity.
Solution Approach 2:
The invention changes the physical state and optical parameters of the electrochromic compounds through electrical stimulation. By applying voltage, the compounds transition between different oxidation states, fundamentally altering their light absorption characteristics and enabling variable light attenuation while preserving the high wavelength flatness achieved through optimized concentration ratios.
3Ease of operation
If variable ND filters combine multiple compounds to achieve variable transmittance, then electrical control is enabled, but the absorption wavelength control is limited and wavelength flatness cannot be optimized
Solution Approach 1:
The patent systematically optimizes the concentration ratios of electrochromic compounds A, B, and C as key parameters to achieve precise control over the combined absorption spectrum. By carefully selecting and adjusting these concentration parameters, the invention achieves both easy electrical operation and superior wavelength flatness (TF ≤ 1.05), overcoming the limitation of conventional variable ND filters that cannot precisely control absorption wavelengths.
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 effectively suppresses light source influence on color reproducibility by optimizing concentration ratios and using electrochromic compounds, enabling high color reproducibility across various light sources and illumination conditions, as demonstrated in camera systems and other optical apparatuses.
Implementation Method 1
a light modulating element (1001) including a plurality of compounds whose light absorption characteristics change by external stimulation
Implementation Method 2
The plurality of compounds are compounds having different absorption wavelengths. The light modulating element has a variable transmittance VT(λ) obtained by combining light absorption characteristics of the plurality of compounds
Data Source
AI summary
There is provided a light modulating element including a plurality of compounds whose light absorption characteristics change with external simulation. The plurality of compounds are compounds having different absorption wavelengths. The light modulating element has a variable transmittance VT(λ) obtained by combining light absorption characteristics of the plurality of compounds. NWDMax<NWDMaxFP is satisfied.