LED Assembly Light Yield via Luminescence Conversion
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Solution Overview
Problem
Modern high-performance LEDs with larger chip sizes face significant challenges in coupling light into optical systems like light guides due to the conservation of etendue, leading to inefficient light usage and power losses, as the increased size of the LED chip exceeds the acceptance angle of the optical system.
Innovation Solution
An LED arrangement featuring a carrier, an LED chip, a reflector that forms an image of the LED chip on a luminescence conversion layer, and a secondary light source, where the reflected light is absorbed and re-emitted at a longer wavelength, allowing for improved light coupling and reduced color temperature, with adjustable reflector configurations for optimal performance and color temperature adjustment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the LED chip size is increased to improve luminous flux and luminance, then the light output is improved, but the coupling efficiency into optical systems deteriorates due to conservation of etendue
Solution Approach 1:
A luminescence conversion layer is introduced as an intermediary between the LED chip and the optical system. This layer absorbs light from the LED chip and re-emits it at different wavelengths, effectively decoupling the etendue constraints from the final light output. The conversion layer acts as a mediator that transforms the spatial and angular distribution of light while converting wavelengths, enabling efficient coupling into optical systems despite large LED chip sizes.
Solution Approach 2:
The invention changes the wavelength parameter of the light by using a luminescence conversion layer that absorbs light at one wavelength and emits at a different wavelength. This parameter change allows the light to meet the acceptance conditions of the optical system while maintaining the benefits of large LED chip sizes for high luminous flux output.
2Power
If the LED chip area is enlarged to achieve competitive luminous flux with discharge lamps, then the light output increases, but the proportion of light meeting acceptance conditions decreases
Solution Approach 1:
The luminescence conversion layer serves as an intermediary that processes light from the large LED chip. It absorbs photons across various angles and wavelengths from the LED chip and re-emits them with modified spectral and angular characteristics, ensuring that a higher proportion of the total light output meets the acceptance conditions of downstream optical systems.
Solution Approach 2:
By changing the wavelength parameter through photoluminescence conversion, the invention enables large LED chips to produce light that satisfies optical system acceptance criteria. The conversion layer transforms the spectral distribution and angular characteristics of the emitted light, improving the fraction of usable light while maintaining high total luminous flux.
3Productivity
If reflected light is used to increase usable light output, then the light yield improves, but the color temperature changes due to luminescence conversion
Solution Approach 1:
The luminescence conversion layer intentionally changes the wavelength parameter of the reflected light, which directly affects the color temperature. By selecting appropriate conversion materials with specific emission spectra, the invention can control and adjust the color temperature of the output light while maximizing the usable light output that meets optical system acceptance conditions.
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 enhances light yield and efficiency by utilizing the reflected light to meet the acceptance conditions of the optical system, increasing usable power and allowing for adjustable color temperature without efficiency losses, thus improving the coupling of light into optical systems.
Implementation Method 1
a luminescence conversion layer onto which at least part of the light reflected by the reflector is directed
Implementation Method 2
a reflector which reflects part of the light emitted by the LED chip during operation of the LED arrangement
Data Source
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AI summary
The invention relates to an LED arrangement (10, 20) with a carrier (1, 21), an LED chip (2, 22) arranged on the carrier (1, 21), and a reflector (6, 27) which reflects a portion of the light emitted by the LED chip (2, 22) during operation of the LED arrangement (10, 20), wherein the LED arrangement (10, 20) has a luminescence conversion layer (3, 23) arranged on the LED chip and onto which at least a portion of the light reflected by the reflector (6, 27) is directed such that an image of the LED chip (2, 22) is projected onto the LED chip, and a method for operating an LED arrangement (10, 20) comprising at least the steps of generating light by means of an LED chip (2, 22), reflecting a portion of the light generated by means of the LED chip (2, 22), and Coupling light into an optical system that has an acceptance condition, whereby only light that meets the acceptance condition is coupled into the optical system.wherein the light is reflected onto a luminescence conversion layer (3,23) in such a way that an image of the LED chip (2,22) is projected onto the LED chip.