Semiconductor Light-Emitting Device with Violet LED and Phosphor Mixture
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Solution Overview
Problem
Existing semiconductor light-emitting devices fail to emit light with a correlated color temperature between 1600 K and 2400 K while maintaining high color rendering index (Ra) and natural candle-like color without bluish tint, due to limitations in phosphor configurations and emission efficiency.
Innovation Solution
A semiconductor light-emitting device is designed using a violet light-emitting diode element with a phosphor mixture including green and red phosphors, where the peak intensity of the light emitted by the diode is less than 60% of the phosphor's maximum peak intensity, and the phosphors are arranged to prevent cascade excitation, allowing for adjustable excitation light ratios to achieve desired color temperatures and high Ra values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a blue LED with standard phosphor configuration is used, then the device structure is simple, but the correlated color temperature cannot be controlled within 1600-2400 K range while maintaining high color rendering index
Solution Approach 1:
The patent segments the phosphor system into multiple distinct phosphor materials (first phosphor, second phosphor, third phosphor) with different emission characteristics. This segmentation allows independent optimization of each phosphor's properties to achieve the target color temperature range and high color rendering index, resolving the contradiction between adaptability and complexity by making the complex system modular and controllable.
Solution Approach 2:
The patent employs a composite phosphor system combining multiple phosphor materials with complementary emission spectra. This composite approach enables precise control over the overall emission spectrum, achieving the difficult-to-obtain correlated color temperature range of 1600-2400 K while maintaining high color rendering, thus improving adaptability without excessive complexity.
2Adaptability or versatility
If the phosphor mixture ratio is adjusted to achieve desired color temperature, then the color temperature is controllable, but the manufacturing process becomes complex
Solution Approach 1:
The patent utilizes parameter changes in the phosphor composition ratios to achieve color temperature control. By establishing specific ratio ranges for different phosphors (first, second, and third phosphors), the invention enables color temperature adjustment within 1600-2400 K through controlled variation of compositional parameters, making the manufacturing process systematic rather than overly complex.
3Illumination intensity
If multiple phosphors are mixed to achieve high color rendering index, then the color rendering improves, but the emission efficiency decreases due to cascade excitation
Solution Approach 1:
The patent applies local quality by assigning specific functional roles to different phosphor materials based on their emission characteristics. Each phosphor is selected and positioned to address specific spectral requirements, optimizing the overall system performance. This localized functional assignment achieves high color rendering index while minimizing energy loss by avoiding unnecessary cascade excitation between phosphors with overlapping absorption and emission spectra.
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 device emits light with a correlated color temperature between 1600 K and 2400 K, achieving high color rendering index and natural candle-like color without bluish tint, while maintaining high emission efficiency and allowing for adjustments in color temperature without complex phosphor ratio changes.
Implementation Method 1
a semiconductor light-emitting element and a phosphor that emits light using the semiconductor light-emitting element as an excitation source
Implementation Method 2
a phosphor that emits light using the semiconductor light-emitting element as an excitation source
Data Source
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AI summary
The present invention provides a semiconductor light-emitting device that emits light with a specific low correlated color temperature and with a high Ra, and a semiconductor light-emitting system provided with the semiconductor light-emitting device. This object is attained by the semiconductor light-emitting device having the below-described configuration. A semiconductor light-emitting device includes a LED chip as a semiconductor light-emitting element, and a phosphor emitting light using the LED chip as an excitation source, and emits light with a correlated color temperature equal to or higher than 1600 K and lower than 2400 K. The phosphor includes at least a green phosphor and a red phosphor. In the spectrum of light emitted from the semiconductor light-emitting device, the value of the peak intensity of the light emitted by the LED chip is less than 60% of the maximum peak intensity of the light emitted by the phosphor.