White Light Emitting Module Crisp White Spectral Tuning
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Solution Overview
Problem
LED-based light sources struggle to produce a 'crisp white' effect with high color rendering index (CRI) similar to conventional light sources, as they often result in a less white appearance of objects due to their narrow spectral band and limited color rendition.
Innovation Solution
A light emitting module comprising at least one first light emitting element emitting light in the blue wavelength range, a wavelength converting material to convert this light into green to red wavelengths, and a second light emitting element emitting deep blue light, which contributes significantly to the total output spectrum, achieving a specific spectral power distribution ratio to produce a 'crisp white' effect.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If conventional LED light sources with narrow spectral bands are used, then light conversion efficiency is improved, but color rendering quality and white appearance are worsened
Solution Approach 1:
The patent divides the light source into multiple LED types with different emission characteristics (first LEDs with 440-460nm peak, second LEDs with 380-440nm peak) and separate wavelength converting materials. This segmentation allows each component to contribute specifically to different parts of the spectrum, achieving both efficiency and color rendering quality.
Solution Approach 2:
The patent uses composite wavelength converting materials including yellow-green phosphors and red phosphors in specific combinations. These composite materials convert the blue and deep blue LED light into a broad spectrum that maintains high efficiency while achieving excellent color rendering (Ra≥95) and crisp white appearance.
2Ease of manufacture
If warm-white or neutral-white LED modules with color rendering of 80-90 are used, then manufacturing simplicity is improved, but white rendition quality is worsened
Solution Approach 1:
The patent changes the spectral parameters by introducing a specific ratio of deep blue light (380-440nm) to normal blue light (440-460nm), with the deep blue component contributing 10-40% to the total blue spectrum. This parameter change shifts the color point below the black body line, achieving crisp white appearance while maintaining straightforward manufacturing with conventional LED assembly processes.
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 module generates a white light with improved white rendition and a 'crisp white' appearance by tuning the color point below the black body line, maintaining a high color rendering index and homogeneous color over various viewing angles, while avoiding the need for additional phosphor conversion of the deep blue light.
Implementation Method 1
at least one wavelength converting material arranged to receive light emitted by said first light emitting element, and being capable of emitting light having an emission peak in the green to red wavelength range
Data Source
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AI summary
A light emitting module, adapted to produce white output light having an emission peak in the wavelength range from 400 to 440 nm, comprises: - at least one first light emitting element adapted to emit light having an emission peak in a first wavelength range from 440 to 460 nm; - at least one wavelength converting material arranged to receive light emitted by said first light emitting element, and being capable of emitting light having an emission peak in the green to red wavelength range; and - at least one second light emitting element adapted to emit light having an emission peak in a second wavelength range from 400 to 440 nm. The module according to the invention provides white light of acceptable color rendering with a "crisp white" effect.