Dual-Phosphor LED Package Layout for Wide Chromaticity Control
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Solution Overview
Problem
Existing light-emitting devices struggle to emit light across a wide range of chromaticity effectively, as they often rely on single wavelength converting members that limit color rendering properties and luminous efficiency.
Innovation Solution
A light-emitting device configuration featuring independently driven first and second light-emitting elements, with a wall portion separating them, and light-transmissive members containing wavelength converting members, where the peak emission wavelength of the first wavelength converting member is longer than that of the second, allowing for enhanced color mixing and chromaticity control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single wavelength converting member is used, then the device structure is simple, but the chromaticity range and color rendering properties are limited
Solution Approach 1:
The patent divides the wavelength converting function into multiple independent members (first wavelength converting member and second wavelength converting member) with different peak emission wavelengths. Each member converts a portion of the blue light from the LED to different wavelength ranges, enabling broader chromaticity coverage and improved color rendering while maintaining a relatively compact structure
Solution Approach 2:
The patent uses composite phosphor materials with different emission characteristics (e.g., yellow phosphor with peak around 560-580nm and red phosphor with peak around 610-650nm) to create a combined wavelength converting layer. This composite approach allows the device to emit light across a wide chromaticity range with high color rendering properties while keeping the overall device structure manageable
2Reliability
If multiple wavelength converting members are used, then the color rendering properties and luminous efficiency are improved, but the device complexity increases
Solution Approach 1:
The patent applies different wavelength converting members with specific emission characteristics to different regions or layers. The first wavelength converting member (e.g., yellow phosphor) and second wavelength converting member (e.g., red phosphor) are positioned to convert blue LED light to complementary wavelength ranges, creating localized color enhancement that collectively improves overall color rendering properties and luminous efficiency
Solution Approach 2:
The patent optimizes parameters such as the peak emission wavelengths, half-widths, and relative intensities of multiple phosphor materials to achieve high color rendering properties. By carefully selecting phosphors with complementary emission spectra and adjusting their ratios, the device achieves improved reliability in color rendering while managing the complexity through parameter optimization rather than structural complexity
3Adaptability or versatility
If wavelength converting members are used to expand chromaticity range, then the color rendering is improved, but the luminous efficiency may be reduced due to multiple conversion steps
Solution Approach 1:
The patent uses multiple wavelength converting members that each handle a specific portion of the blue LED spectrum. Rather than attempting to convert all blue light through a single phosphor (which would cause excessive energy loss), the system divides the conversion task among multiple phosphors with different emission characteristics, reducing overall energy loss while expanding chromaticity range
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 configuration enables the light-emitting device to achieve high luminous efficiency and color rendering properties by adjusting the type and quantity of wavelength converting members, resulting in a wide range of chromaticity emission.
Implementation Method 1
a first light-transmissive member separated from the second light-emitting element by the wall portion and covering at least a portion of lateral surfaces of the first light-emitting element, and containing a first wavelength converting member; and a second light-transmissive member covering the first light-emitting element, the second light-emitting element, and the first light-transmissive member in a plan view, and containing a second wavelength converting member; in which a peak emission wavelength of the first wavelength converting member is longer than a peak emission wavelength of the second wavelength converting member
Data Source
AI summary
A light-emitting device includes: a first light-emitting element and a second light-emitting element, each configured to be independently driven; a wall portion located between the first light-emitting element and the second light-emitting element; a first light-transmissive member separated from the second light-emitting element by the wall portion and covering at least a portion of lateral surfaces of the first light-emitting element, wherein the first light-transmissive member contains a first wavelength converting member; and a second light-transmissive member covering the first light-emitting element, the second light-emitting element, and the first light-transmissive member in a plan view, wherein the second light-transmissive member contains a second wavelength converting member. A peak emission wavelength of the first wavelength converting member is longer than a peak emission wavelength of the second wavelength converting member.