Blue and Red LED Lighting Apparatus for High CRI
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Solution Overview
Problem
White light LEDs face challenges in achieving a desired Color Rendering Index (CRI) and correlated color temperature (CCT) due to a lack of red light in their spectrum, leading to inefficient energy transition and reduced light emitting efficiency.
Innovation Solution
Incorporating both blue and red light-emitting diode dies with a specific electrical-connection structure, where the power ratio between blue and red diodes is adjusted to optimize correlated color temperature and CRI, utilizing a phosphor layer to generate yellow-green light and enhance light mixing efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a phosphor layer is coated on blue light LED to generate white light, then the light emitting efficiency is improved, but the color rendering index (CRI) deteriorates due to lack of red light in spectrum
Solution Approach 1:
The patent combines blue light LED and red light LED into a single lighting apparatus, merging two different light sources to produce a composite spectrum that includes both blue and red wavelengths. This merging enables the system to achieve high CRI (>85) while maintaining efficient light emission, resolving the contradiction between light emitting efficiency and color rendering quality.
2Manufacturing precision
If red light-emitting diode is added to improve CRI, then the color rendering index is improved, but the device complexity increases
Solution Approach 1:
The patent segments the lighting apparatus into distinct blue light LED and red light LED components, each performing a specific function. The blue LED provides primary illumination while the red LED supplements the spectrum for better CRI. This segmentation allows for modular design and simplified manufacturing, reducing overall device complexity despite adding functional components.
Solution Approach 2:
The lighting apparatus is designed with multi-functionality, where the blue LED serves both as a primary light source and as a component that, when combined with the red LED, creates a high CRI illumination system. The shared electrical connection structure and integrated design enable both LEDs to work together efficiently, reducing the need for separate control systems and simplifying the overall device architecture.
3Ease of manufacture
If power ratio between blue and red diodes is not optimized, then the manufacturing is simplified, but the correlated color temperature control deteriorates
Solution Approach 1:
The patent implements parameter changes by establishing specific power ratio ranges (7.67×ln(TN)−56.6 to 5.01×ln(TN)−37.2) that directly control the correlated color temperature (CCT). This quantitative parameter optimization enables manufacturers to achieve precise CCT control while maintaining ease of manufacture through standardized power distribution ratios, resolving the contradiction between manufacturing simplicity and temperature control precision.
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 solution achieves a CRI greater than 85 and a correlated color temperature within a desired range, improving the light emitting efficiency and color rendering capabilities of white light LEDs.
Implementation Method 1
The phosphor is a photoluminescence material which absorbs an electro-magnetic wave on a part of the light spectrum and emits another electro-magnetic wave on another part of the light spectrum
Implementation Method 2
The light-emitting diode (LED) is a lighting source made of semiconductors
Data Source
AI summary
Disclosed are a lighting apparatus and its driving method. A disclosed lighting apparatus comprises a blue light-emitting diode die, a red light-emitting diode die, an electrical-connection structure connecting the blue light-emitting diode die and the red light-emitting diode die and having a correlated color temperature TN. A disclosed driving method of a lighting apparatus comprising operating a blue light-emitting diode emitting a first color light with an electrical power WB consumed and operating a red light-emitting diode die emitting a second color light with an electrical power WR consumed, respectively. Then, the correlated color temperature of the lighting apparatus is about TN, and a power ratio RW, the ratio of WB over WR, is about between 7.67*ln(TN)−56.6 and 5.01*ln(TN)−37.2.