Composite Optical Filter for Angle-Stable UV and IR Blocking
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Solution Overview
Problem
Existing optical filters face challenges in maintaining stable transmission and blocking characteristics across varying incident angles, leading to issues like ripple and petal flare, while also requiring high visible light transmittance and effective blocking of ultraviolet and infrared rays, especially in harsh conditions.
Innovation Solution
An optical filter design comprising an infrared-absorbing substrate with copper and specific dielectric films, structured with alternating sub-layers of varying refractive indices, optimized by V values and copper content to achieve stable transmission and blocking characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a dielectric film is used to block ultraviolet and infrared light, then blocking characteristics are improved, but transmittance curve shifts depending on incident angle
Solution Approach 1:
The patent combines a dielectric film with an absorption layer containing a near-infrared absorbing dye to create a composite optical filter. The dielectric film provides the primary blocking function while the absorption layer compensates for incident angle dependence, achieving both effective blocking and angle independence through material composition.
Solution Approach 2:
The patent adjusts the optical parameters of the absorption layer, specifically using a near-infrared absorbing dye with controlled absorption characteristics. By optimizing the dye concentration and layer properties, the system maintains stable transmittance across different incident angles while preserving blocking effectiveness.
2Adaptability or versatility
If an absorption layer containing near-infrared absorbing dye is used to compensate for dielectric film angle dependence, then incident angle dependence is reduced, but visible light transmittance may be affected
Solution Approach 1:
The absorption layer is positioned specifically at the interface between the dielectric film and the substrate, creating a localized functional zone. This positioning allows the absorption layer to compensate for angle dependence without significantly impacting visible light transmittance, as it is concentrated where it is most effective for blocking infrared radiation.
Solution Approach 2:
The patent optimizes the optical parameters of the absorption layer by selecting a near-infrared absorbing dye with specific absorption characteristics. The dye concentration and layer thickness are controlled to achieve angle independence while maintaining high visible light transmittance, balancing the competing requirements.
3Object-affected harmful factors
If infrared absorbing glass is used as substrate to block near-infrared light, then infrared blocking is improved, but visible light transmittance is reduced
Solution Approach 1:
Instead of using infrared absorbing glass as the substrate, the patent employs a transparent substrate combined with a dielectric film and an absorption layer. This composite structure achieves infrared blocking through the coordinated action of these layers while maintaining high visible light transmittance, avoiding the inherent limitation of infrared absorbing glass.
Solution Approach 2:
The patent extracts the infrared absorption function from the substrate and relocates it to a separate absorption layer positioned at the dielectric-substrate interface. This separation allows the substrate to be fully transparent for visible light while the dedicated absorption layer handles infrared blocking, resolving the trade-off between the two functions.
4Illumination intensity
If dielectric film transmittance is increased to obtain clearer pictures, then image quality is improved, but petal flare phenomenon increases
Solution Approach 1:
The absorption layer is strategically positioned at the interface between the dielectric film and substrate, creating a localized zone that specifically targets and absorbs near-infrared radiation. This localized placement prevents petal flare by blocking infrared light at the critical interface region without affecting the overall transmittance needed for image clarity.
Solution Approach 2:
The patent converts the potentially harmful near-infrared radiation that causes petal flare into a beneficial effect by using the absorption layer to selectively absorb this radiation. The absorbed energy is dissipated as heat, effectively eliminating the petal flare phenomenon while maintaining the high transmittance necessary for clear imaging.
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 filter effectively blocks ultraviolet and infrared rays, maintains high visible light transmittance, and prevents ripple and petal flare, ensuring durability and consistent performance across changing angles.
Implementation Method 1
An infrared absorbing substrate containing copper; a first dielectric film formed on a first surface of the infrared absorbing substrate
Implementation Method 2
a first dielectric film formed on a first surface of the infrared absorbing substrate and including a structure where a first sub-layer and a second sub-layer, respectively, having a different refractive index are repeatedly stacked
Implementation Method 3
a first dielectric film formed on a first surface of the infrared absorbing substrate and including a structure where a first sub-layer and a second sub-layer, respectively, having a different refractive index are repeatedly stacked
Data Source
AI summary
The present invention provides an optical filter for its use. In the present invention, it is possible to provide an optical filter that effectively blocks ultraviolet ray and infrared ray and exhibits high transmittance in visible light. Furthermore, it is possible to provide an optical filter where the transmission characteristics are stably maintained even when an incident angle is changed. Moreover, it is possible to provide an optical filter that does not exhibit problems such as ripple, petal flare, and curl.