LED Lighting Device Blue Light Filtering for Color Rendering
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Solution Overview
Problem
Conventional lighting technologies, such as incandescent and fluorescent bulbs, are inefficient and have limitations in color rendering index (CRI) and lifespan, while solid-state light emitters like LEDs face challenges in producing white light with desirable color temperature and CRI.
Innovation Solution
A method involving a lighting device with a white light source and a filter that removes blue light, supplemented with red or reddish-orange light to improve CRI and color temperature, utilizing a filter system with movable components to adjust the exiting light color.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If solid state light emitters (LEDs) are used to improve energy efficiency, then energy consumption is reduced, but color rendering index (CRI) and color temperature are degraded
Solution Approach 1:
The patent segments the white light emission into multiple wavelength components (blue, green, yellow, red) and processes each segment independently through specific filters. This allows selective enhancement of certain wavelength ranges while maintaining overall energy efficiency, thereby improving CRI without sacrificing the energy benefits of LED technology.
Solution Approach 2:
The patent employs composite filtering systems that combine multiple filter materials with different spectral characteristics. By layering or combining filters with complementary transmission properties, the system achieves broadspectral enhancement across multiple wavelength ranges, improving color rendering while maintaining LED energy efficiency.
2Reliability
If blue light is filtered from white light to improve CRI, then color rendering is enhanced, but luminous output (lumens) is reduced
Solution Approach 1:
The patent applies local quality enhancement by selectively filtering and enhancing specific wavelength regions (green 500-560nm, yellow 560-590nm, red 610-680nm) while allowing other regions to pass through. This localized spectral modification improves CRI in critical wavelength ranges without uniformly reducing the entire spectrum, thus preserving overall luminous output.
Solution Approach 2:
The patent converts the potentially harmful effect of blue light filtering (which would normally reduce total lumens) into a benefit by compensating with enhanced green, yellow, and red light components. The filtered blue light energy is effectively redistributed to enhance other wavelength regions that are critical for color rendering, turning a loss into a gain for overall color quality.
3Reliability
If multiple light sources and filters are combined to improve CRI, then color rendering is enhanced, but device complexity increases
Solution Approach 1:
The patent merges multiple filtering functions into a single integrated filter assembly that simultaneously performs blue light attenuation and green/yellow/red light enhancement. By combining what would otherwise be separate filter components into one unified structure, the system achieves complex spectral modification without proportionally increasing device complexity.
Solution Approach 2:
The filter assembly is designed with multi-functionality, serving both to block harmful blue light and to enhance desirable green, yellow, and red wavelength ranges simultaneously. This universal filter design accomplishes multiple spectral modification goals with a single component, reducing the need for multiple separate devices and simplifying the overall system architecture.
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 enhances the CRI and color temperature of LED light sources, producing white light with improved efficacy and reduced energy loss, achieving a color temperature closer to traditional lighting sources without significant lumens reduction.
Implementation Method 1
a first filter which, if contacted by the white light emitted from the first light source, would filter at least some blue light from the white light to form modified light
Implementation Method 2
a second light source which, if illuminated, emits light of at least one color selected from among the group consisting of red light and reddish-orange light
Data Source
AI summary
A lighting device comprising a white light source, a filter which filters blue light from the white light, and a second light source which emits red light and/or reddish-orange light. In some embodiments, the white light source comprises a solid state light emitter. A method of lighting, comprising illuminating a white light source, illuminating a red and/or reddish-orange light source, the light sources being positioned and oriented such that the light mixes, and filtering blue light from the mixed light. A method of lighting, comprising illuminating a white light source, filtering blue light from the white light, and illuminating a red and/or reddish-orange light source. A light filter, comprising a first filter component which has a wall region and a window region, and a second filter component comprising two or more reflection regions. Also, methods of filtering.