LED Package with Wavelength Conversion and Optical Filter
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Solution Overview
Problem
Existing LED packages that aim to display three primary colors using LEDs of different colors complicate configuration and increase power consumption due to varying operating voltages.
Innovation Solution
An LED package is designed with a light-emitting structure, an optical wavelength conversion layer, and an optical filter layer to convert and filter light, allowing a single LED to emit multiple colors, including a three-color light-emitting apparatus for display devices, where the optical filter layer reflects the initial light and transmits the converted light, optimizing power usage and simplifying configuration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If LEDs of different colors are used to display three primary colors, then the display capability is improved, but the device complexity and power consumption increase due to different operating voltages
Solution Approach 1:
The patent uses a single blue LED that performs multiple functions: it directly emits blue light and also serves as a pump source for wavelength conversion layers that generate red and green light. This multi-functional approach eliminates the need for separate LEDs for each primary color, reducing configuration complexity while maintaining full-color display capability
Solution Approach 2:
The patent introduces wavelength conversion layers (phosphors) as intermediary materials that convert blue light from the LED into red and green light. These intermediary layers enable a single LED to produce multiple colors through optical conversion rather than requiring multiple LEDs with different operating voltages
2Adaptability or versatility
If LEDs of different colors are used to display three primary colors, then the display capability is improved, but the power consumption increases due to varying operating voltages
Solution Approach 1:
A single blue LED with fixed operating voltage performs multiple functions: direct blue light emission and pump source for wavelength conversion to red and green. This eliminates the need for multiple LEDs with different operating voltages, thereby reducing overall power consumption while maintaining full-color display capability
Solution Approach 2:
The patent changes the approach from varying electrical parameters (different voltages for different colored LEDs) to varying optical parameters (wavelength conversion from blue light to red and green light). This parameter transformation allows a single LED operating at one voltage to produce multiple colors, reducing power consumption
3Device complexity
If a single LED is used to emit multiple colors through wavelength conversion, then the device complexity is reduced, but the light extraction efficiency may be affected by total internal reflection at interfaces
Solution Approach 1:
The patent employs a dome-shaped lens structure at the top of the package that curves the light paths. This spherical/curved geometry helps redirect internally reflected light toward the emission direction, reducing total internal reflection losses and improving light extraction efficiency while maintaining the simple single-LED configuration
Solution Approach 2:
The patent uses wavelength conversion layers with different emission characteristics (red and green phosphors) that have different refractive indices and light extraction properties. By optimizing the composition and distribution of these color-converting layers, the patent improves overall light extraction efficiency across different wavelengths while maintaining configuration simplicity
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 enables efficient power management and simplified configuration by allowing a single LED to emit multiple colors, enhancing the display capabilities of LED packages while reducing power consumption and complexity.
Implementation Method 1
an optical wavelength conversion layer disposed on the light-emitting structure and configured to absorb the first light emitted from the light-emitting structure and emit second light having a second peak wavelength different from the first peak wavelength
Implementation Method 2
an optical filter layer disposed on the optical wavelength conversion layer and configured to reflect the first light emitted from the light-emitting structure and transmit the second light emitted from the optical wavelength conversion layer
Data Source
AI summary
A light-emitting diode (LED) package includes a light-emitting structure, an optical wavelength conversion layer on the light-emitting structure, and an optical filter layer on the optical wavelength conversion layer. The light-emitting structure includes a first-conductivity-type semiconductor layer, an active layer on the first-conductivity-type semiconductor layer, and a second-conductivity-type semiconductor layer on the active layer, and emits first light having a first peak wavelength. The optical wavelength conversion layer absorbs the first light emitted from the light-emitting structure and emits second light having a second peak wavelength different from the first peak wavelength. The optical filter layer reflects the first light emitted from the light-emitting structure and transmits the second light emitted from the optical wavelength conversion layer.