High Efficiency LED Lamp with Remote Phosphor Optical Element
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Solution Overview
Problem
Current LED lighting systems face challenges in achieving high efficiency and color rendering index (CRI) while providing warm white light with a correlated color temperature (CCT) within specific ranges, which is essential for replacing traditional lighting solutions in various applications.
Innovation Solution
The development of a high-efficiency LED lamp with an optical element that receives light from an LED assembly, featuring a primary exit surface spaced apart to enhance light output and efficiency, combined with an optical overlay and a heatsink, utilizing a combination of red-emitting and blue-shifted-yellow (BSY) emitting LEDs with phosphors to produce warm white light with a CRI of at least 90 and a CCT between 2500 to 3500 K.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If LED assembly is positioned close to the optical element, then light output efficiency is improved, but color rendering index and color temperature control deteriorate
Solution Approach 1:
The patent spaces the primary exit surface of the optical element away from the LED assembly in the axial dimension, creating a remote phosphor configuration. This dimensional separation allows the light to travel through a medium containing phosphors that convert the LED wavelength to achieve the desired color temperature and CRI, resolving the contradiction between efficiency and color rendering control.
Solution Approach 2:
The patent introduces a medium containing phosphors (such as yellow phosphors like Y3Al5O12:Ce or red phosphors like CaAlSiN3:Eu) as an intermediary between the LED assembly and the external environment. This intermediary converts the LED's native wavelength to achieve the target color temperature range (2200K-3000K) and CRI (>90), resolving the color rendering issue while maintaining efficiency through optimized phosphor placement and composition.
2Manufacturing precision
If multiple LED types are combined to achieve warm white light, then color rendering is improved, but device complexity increases
Solution Approach 1:
The patent achieves warm white light (2200K-3000K) by changing the phosphor parameters - specifically using yellow phosphors with appropriate emission spectra or red phosphors with specific characteristics. This parameter-based approach (phosphor material composition and emission wavelength) simplifies the system compared to combining multiple LED types, as it requires only a single LED wavelength with phosphor conversion rather than multiple LED chips with different wavelengths.
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 light output of at least 1200 lumens with an efficiency of 160-180 lumens per watt and a CRI of 90, meeting the requirements for high-efficiency and color rendering standards, such as the L Prize category, with a CCT suitable for warm white lighting.
Implementation Method 1
utilizing a combination of red-emitting and blue-shifted-yellow (BSY) emitting LEDs with phosphors to produce warm white light with a CRI of at least 90 and a CCT between 2500 to 3500 K
Implementation Method 2
combined with an optical overlay and a heatsink
Data Source
AI summary
A high-efficiency LED lamp is disclosed. Embodiments of the invention provide a high-efficiency, high output solid-state lamp. The lamp includes an LED assembly, an optical element disposed to receive light from the LED assembly, and an optical overlay. The optical element includes a primary exit surface, wherein the primary exit surface is at least about 1.5 inches from the LED assembly. In example embodiments, the optical element is roughly cylindrical in shape, but can take other shapes and be made from various materials. An LED lamp according to some embodiments of the invention has an efficiency of at least about 160 lumens per watt. In some embodiments, the lamp has a light output of at least 1200 lumens. In some embodiments, the LED lamp produces light with a color rendering index (CRI) of at least 90 and a warm white color.