Parallel LED Layout With Matched Phosphor Areas for Heat Balance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
When multiple light emitting elements are connected in parallel, some elements can be damaged by heat due to differences in forward voltage and current density caused by variations in the area of the light emitting elements.
Innovation Solution
A light emitting device comprising an inner light emitting part with an inner light emitting element and an inner wavelength conversion member, and multiple outer light emitting parts connected in parallel, each with an outer light emitting element and an outer wavelength conversion member. The outer light emitting parts include a first and a second light emitting part with wavelength conversion members of different areas, and the ratio of the forward voltage of the first light emitting element to the second is maintained between 0.95 and 1.05.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If multiple light emitting elements are connected in parallel with different areas, then the device can provide higher total luminous output, but some elements can be damaged by heat due to differences in forward voltage and current density
Solution Approach 1:
The patent applies local quality by making the wavelength conversion members have different areas corresponding to their respective light emitting elements. This creates localized optical properties that compensate for the different areas of light emitting elements, ensuring uniform light extraction and reducing current density differences. The wavelength conversion member's area is specifically designed to match the light emitting element's area, creating a proportional relationship that balances the electrical and optical characteristics across parallel-connected elements.
Solution Approach 2:
The patent changes the area parameter of wavelength conversion members to compensate for variations in light emitting element areas. By adjusting the wavelength conversion member area as a compensating parameter, the system maintains uniform current density and forward voltage characteristics across parallel-connected elements with different areas, thereby preventing heat damage while preserving total luminous output capability.
2Adaptability or versatility
If light emitting elements with different areas are used to increase device flexibility, then adaptability improves, but forward voltage differences cause current distribution imbalance and heat damage
Solution Approach 1:
The patent applies local quality by tailoring the wavelength conversion member area to each specific light emitting element's area. This localized adaptation allows the device to accommodate light emitting elements of different areas while maintaining uniform electrical characteristics. Each wavelength conversion member is specifically sized to match its corresponding light emitting element, creating a localized compensation mechanism that preserves current distribution uniformity despite variations in element areas.
Solution Approach 2:
The patent uses parameter changes by varying the wavelength conversion member area as a compensating parameter for light emitting element area variations. This parameter adjustment strategy enables the system to maintain consistent forward voltage and current density across elements with different areas, thereby preserving both device flexibility and electrical uniformity simultaneously.
3Ease of manufacture
If the area of wavelength conversion members is made uniform across all light emitting parts, then manufacturing simplicity increases, but light extraction efficiency decreases for elements with different areas
Solution Approach 1:
The patent applies local quality by making the wavelength conversion member area correspond to the light emitting element area for each specific position. This localized customization optimizes light extraction efficiency for each element by ensuring the wavelength conversion member covers the appropriate area, allowing maximum light conversion while minimizing energy loss. The local quality approach ensures that each wavelength conversion member is precisely sized for its corresponding light emitting element, thereby optimizing overall system efficiency.
4Adaptability or versatility
If light emitting elements with significantly different areas are connected in parallel, then device design flexibility increases, but forward voltage ratio deviations cause current density imbalance and heat generation
Solution Approach 1:
The patent applies local quality by designing wavelength conversion members with areas that correspond to their respective light emitting elements. This localized compensation mechanism addresses the heat generation issue by ensuring uniform current density distribution across elements with different areas. The wavelength conversion member area is specifically tailored to each light emitting element, creating a localized balance that prevents current concentration and reduces heat generation in high-power-density regions.
Solution Approach 2:
The patent uses parameter changes by adjusting the wavelength conversion member area as a compensating parameter for light emitting element area variations. This parameter adjustment strategy maintains forward voltage ratios within acceptable ranges (0.95-1.05), thereby preventing current density imbalance and reducing heat generation even when elements with significantly different areas are connected in parallel.
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
This configuration reduces heat damage to light emitting elements connected in parallel by minimizing differences in forward voltage and current density, thereby enhancing the reliability of the light emitting device.
Implementation Method 1
an inner wavelength conversion member disposed on the inner light emitting element and a plurality of outer light emitting parts disposed around the inner light emitting part
Data Source
AI summary
A light emitting device includes: an inner light emitting part including an inner light emitting element, and an inner wavelength conversion member disposed on the inner light emitting element, and a plurality of outer light emitting parts disposed around the inner light emitting part and connected in parallel to one another, each outer light emitting part including an outer light emitting element, and an outer wavelength conversion member disposed on the outer light emitting element. The outer light emitting parts include a first light emitting part that includes a first light emitting element and a first wavelength conversion member, and a second light emitting part that includes a second light emitting element and a second wavelength conversion member.