Individually Compensated Multi-Color LED Clusters
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Solution Overview
Problem
Conventional solid state lighting devices face challenges in maintaining constant color point and efficiency due to temperature variations, especially when using red and blue LEDs, which leads to increased complexity, cost, and potential misperception of device failure during temperature protection.
Innovation Solution
A lighting device with multiple solid state emitters of different peak wavelengths and a temperature compensation circuit that adjusts current supply based on temperature sensing, eliminating the need for light sensing elements and allowing for individually temperature-compensated multi-color LED clusters, each tuned to a consistent color point.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If multiple solid state emitters of different colors are used to produce white light, then color reproduction and efficiency are improved, but color stability and temperature control become more difficult
Solution Approach 1:
The patent divides the lighting device into multiple independent clusters, with each cluster containing emitters of different colors (e.g., red, green, blue LEDs). Each cluster is independently temperature-compensated, allowing separate control of color emissions from different clusters. This segmentation enables the system to maintain color stability by adjusting individual clusters based on their specific temperature characteristics while achieving good color reproduction through the combination of multiple colors.
Solution Approach 2:
The patent implements local temperature compensation by placing temperature sensing elements and compensation circuits within or near each cluster of emitters. This allows each cluster to have its own temperature control characteristics tailored to its specific emitter composition, improving color stability locally while maintaining overall system color reproduction through the combination of all clusters.
2Stability of the object's composition
If temperature compensation circuits are added to maintain constant color point, then color stability is improved, but device complexity increases
Solution Approach 1:
The patent combines multiple functions into integrated temperature compensation circuits that simultaneously perform temperature sensing, current adjustment, and color stabilization. By merging these functions into unified circuits for each cluster, the patent reduces overall device complexity compared to having separate circuits for each function, while still achieving constant color point maintenance through coordinated control of multiple emitters.
3Measurement precision
If light sensing elements are used to adjust current supply, then color control precision is improved, but manufacturing cost and complexity increase
Solution Approach 1:
The patent replaces optical sensing mechanisms with temperature-based electrical control. Instead of using light sensing elements to detect and adjust current, the patent uses temperature sensing elements that detect temperature changes and automatically adjust current supply through electrical compensation circuits. This substitution eliminates the need for complex optical sensing and processing systems, simplifying manufacturing while maintaining color control precision through temperature-correlated current adjustment.
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 solution reduces color and temperature variations across the device, increases the utilization of pre-manufactured LED components, simplifies manufacturing and wiring, and provides a more reliable and efficient LED lighting solution.
Implementation Method 1
at least one temperature sensing element arranged to sense temperature of at least one LED chip
Implementation Method 2
at least one LED chip including different colors when operated at a constant color point
Implementation Method 3
at least one temperature compensation circuit element arranged to adjust supply of current to the at least one LED chip
Data Source
Figure 1~2E
Figure 2A~2D
Figure 3~4
AI summary
A lighting device includes multiple solid state emitter (e.g., LED) chips of different colors mounted on a single submount, at least one temperature sensing element arranged to sense temperature of the LED chips, and at least one temperature compensation circuit element mounted on the single submount to maintain output emissions at a substantially constant color point over a range of different temperatures. Such a device may include a blue LED arranged to stimulate a yellow lumiphor and a red LED, arranged in combination to yield warm white light. Multiple separately temperature compensated clusters of solid state emitters may be provided in a single lighting device, which may include an elongated body structure.