LED Chromaticity Correction via Constant Current Adjustment
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Solution Overview
Problem
Chromaticity variation in vehicle interior illumination due to luminous intensity and wavelength differences among LEDs, leading to quality issues, and existing solutions require software changes for each LED control unit, increasing costs.
Innovation Solution
Adjusting the constant current values of constant current elements without altering the control signal to correct chromaticity variation, allowing multiple LED units to converge to a target chromaticity coordinate, thereby eliminating the need for software changes in LED control units.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If software of LED control unit is changed to correct chromaticity variation, then chromaticity uniformity is improved, but device complexity and cost increase
Solution Approach 1:
The patent replaces the software-based correction method with a hardware-based solution using constant current elements. Instead of modifying control signals through software processing, the invention uses electrical circuit elements (constant current sources) to directly regulate LED current, thereby eliminating the need for complex software algorithms and reducing control unit complexity while maintaining chromaticity uniformity
Solution Approach 2:
The invention changes the operating parameter (current) of each LED by introducing constant current elements with specific current values. By adjusting the current parameter at the hardware level rather than modifying control software, the system achieves chromaticity correction through physical parameter adjustment, simplifying the overall control architecture
2Manufacturing precision
If software correction is implemented for each full-color LED unit, then chromaticity variation is reduced, but manufacturing cost increases
Solution Approach 1:
The patent employs constant current elements, which are simple, inexpensive hardware components compared to software development and customization costs. These basic electrical components can be easily manufactured and integrated into each LED unit, providing an cost-effective solution for chromaticity correction without requiring expensive software licensing, development, or updates
Solution Approach 2:
The invention applies individual constant current elements to each full-color LED unit, segmenting the correction approach into independent, standardized modules. This segmentation allows each unit to be manufactured with the same simple hardware solution rather than requiring customized software for each unit, thereby reducing overall manufacturing complexity and cost
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
Prevents chromaticity variation across multiple LED units at a lower cost by setting unique constant current values for each LED, ensuring consistent illumination without software adjustments.
Implementation Method 1
a constant current element 212R, 212G, 212B configured to supply a constant current to the corresponding LED 211R, 211G, 211B
Data Source
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AI summary
A light emitting apparatus includes a plurality of full-color LED units. Constant current values of the constant current elements are set such that the plurality of full-color LED units come closer to a same chromaticity as compared with a case in which all the constant current elements of all the full-color LED units have a same constant current value. As a result, in at least one of the plurality of full-color LED units, at least one of the plurality of constant current elements is set to a constant current value different from that of the other constant current elements.