Dual-Source LED Light Mixing for Melanopic Ratio Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing tonable and dimmable LED illumination devices struggle to simultaneously control the melanopic ratio for circadian rhythm regulation and maintain light emission efficiency, particularly when attempting to reproduce the chronological change of sunlight and achieve chromaticity near the blackbody radiation locus.
Innovation Solution
A light emitting device comprising a first light source with a peak wavelength between 410 nm and 490 nm and a second light source with a peak wavelength between 410 nm and 460 nm, along with a second fluorescent material, is designed to emit mixed color light within specific chromaticity coordinates, maintaining a light emission intensity ratio and color deviation to achieve optimal melanopic ratio control and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional LED illumination devices use blue light emitting elements with yellow fluorescent materials to generate white light, then the device can achieve general illumination functionality, but the melanopic ratio cannot be effectively controlled for circadian rhythm regulation
Solution Approach 1:
The illumination device divides the light source into multiple independent LED chips with different peak wavelengths (430-470nm for first LED, 460-480nm for second LED). This segmentation allows independent control of each LED's output to precisely regulate the melanopic ratio while maintaining overall illumination functionality, resolving the contradiction between circadian rhythm regulation capability and device complexity.
Solution Approach 2:
Different regions of the spectrum are assigned different functions: the first LED (430-470nm) primarily provides general illumination and excites yellow fluorescent material, while the second LED (460-480nm) specifically targets melanopsin absorption peaks to control circadian rhythm. This local quality differentiation enables simultaneous achievement of illumination and circadian regulation without excessive complexity.
2Adaptability or versatility
If the light emission spectrum is adjusted to increase melanopic ratio for circadian rhythm control, then circadian rhythm regulation improves, but light emission efficiency decreases
Solution Approach 1:
The device independently adjusts the emission intensity parameters of two LED chips with different peak wavelengths. By changing the ratio of output intensity between the first LED (430-470nm) and second LED (460-480nm), the system can dynamically control the melanopic ratio while maintaining acceptable light emission efficiency, resolving the contradiction between melanopic ratio control and energy loss.
Solution Approach 2:
The illumination device uses a composite light source configuration combining two types of LED chips with complementary wavelength characteristics. This composite approach allows the system to achieve both efficient illumination (through the first LED's broader spectrum) and effective circadian control (through the second LED's targeted 460-480nm output that matches melanopsin absorption peaks), thereby resolving the efficiency-melanopic ratio contradiction.
3Stability of the object's composition
If conventional LEDs attempt to reproduce chronological change of sunlight and achieve chromaticity near blackbody radiation locus, then color rendering improves, but the ability to control melanopic ratio for circadian rhythm is compromised
Solution Approach 1:
The device dynamically adjusts the emission intensity ratio between two LED chips with different peak wavelengths based on temporal requirements. During daytime hours, the system can increase melanopic content by enhancing the second LED (460-480nm) output, while during evening hours, it can reduce melanopic stimulation. This dynamic control allows simultaneous achievement of chromaticity stability near blackbody radiation locus and melanopic ratio adaptability for circadian rhythm regulation.
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 effectively controls the melanopic ratio for circadian rhythm regulation while maintaining high light emission efficiency, suitable for various illumination applications by adjusting the correlated color temperature to simulate natural sunlight conditions.
Implementation Method 1
a light emitting device that emits white based mixed color light by using a light emitting element emitting blue light and a fluorescent material emitting yellow light through excitation with light from the light emitting element
Implementation Method 2
melanopsin has a peak wavelength of from around 480 nm to around 490 nm... The light receptor substance has been known to have different absorption characteristics depending on the cells
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A light emitting device includes a first light source containing a first light emitting element, and a second light source containing a second light emitting element and a second fluorescent material, the first light source emits light in a region that is demarcated in a chromaticity diagram of the CIE 1931 color coordinate system by a first straight line connecting a first point having x,y of 0.280,0.070 in the chromaticity coordinate and a second point having x,y of 0.280,0.500 in the chromaticity coordinate, a second straight line connecting the second point and a third point having x,y of 0.013,0.500 in the chromaticity coordinate, a purple boundary extending from the first point toward a direction decreasing x in the chromaticity coordinate, and a spectrum locus extending from the third point toward a direction decreasing y in the chromaticity coordinate, in a light emission spectrum, a light emission intensity ratio IPM/IPL of a light emission intensity IPM at a wavelength of 490 nm with respect to a light emission intensity IPL at a maximum light emission peak wavelength of the first light emitting element is in a range of 0.22 or more and 0.95 or less, the second light source emits light having a color deviation duv from a blackbody radiation locus in a range of -0.02 or more and 0.02 or less measured according to JIS Z8725 with a correlated color temperature in a range of 1,500 K or more and 8,000 K or less in a chromaticity diagram of the CIE 1931 color coordinate system, and the light emitting device emits mixed color light of light emitted from the first light source and light emitted from the second light source.