Solid State Lighting Device with Multi-String Current Tuning
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Solution Overview
Problem
There is a need for lighting devices that provide consistent color temperature and improved energy efficiency, longer lifespan, and better color rendering index, particularly in applications where incandescent and fluorescent lights are inefficient and require frequent replacements, such as in difficult-to-access locations or high-cost maintenance areas.
Innovation Solution
A lighting device comprising multiple strings of solid state light emitters with adjustable currents to achieve desired color output, using a method that involves measuring and adjusting the current supplied to each string to ensure consistent color coordinates on a CIE Chromaticity Diagram, allowing for tuning after manufacturing to account for variability in light emitters and maintain color output over time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If incandescent light bulbs are used, then color rendering index is improved (Ra > 95), but energy efficiency deteriorates (90% electricity released as heat)
Solution Approach 1:
The patent changes the physical parameters of light emission by using solid state light emitters with specific dominant wavelengths (430-480nm blue, 560-580nm yellow-green, 600-680nm red) to achieve high CRI through spectral composition rather than thermal radiation, thereby improving energy efficiency while maintaining color rendering
Solution Approach 2:
The patent employs composite lighting systems combining multiple types of solid state light emitters (different wavelengths and technologies) to create a composite light spectrum that achieves superior CRI (>95) while maintaining high energy efficiency, replacing the single-source incandescent approach
2Measurement precision
If incandescent light bulbs are used, then color rendering index is improved (Ra > 95), but lifespan deteriorates (750-1000 hours)
Solution Approach 1:
The patent replaces expensive, short-lived incandescent bulbs with solid state light emitters that have extremely long operational lifetimes (50,000-70,000 hours), eliminating the need for frequent replacements in hard-to-access locations while maintaining superior color rendering
Solution Approach 2:
The patent changes the operational parameters by using solid state light emitters that operate without the thermal degradation mechanisms limiting incandescent bulb lifespan, achieving both extended service life and high CRI through non-thermal light generation
3Loss of energy
If solid state light emitters are used, then energy efficiency is improved, but color consistency deteriorates (variability in light output)
Solution Approach 1:
The patent segments the lighting system into multiple independent strings of solid state light emitters with different dominant wavelengths, allowing individual current adjustment for each string to achieve precise color mixing and consistent overall color output despite variations in individual emitter performance
Solution Approach 2:
The patent implements dynamic current adjustment capabilities for each string of solid state light emitters, enabling real-time optimization of color output and compensation for emitter variability, thereby achieving consistent color temperature and CRI while maintaining high energy efficiency
4Stability of the object's composition
If multiple strings of solid state light emitters with adjustable currents are used, then color consistency is improved, but device complexity increases
Solution Approach 1:
The patent divides the lighting device into multiple independent strings of solid state light emitters, each with independent current control, enabling precise color mixing and consistency while maintaining modular simplicity that facilitates manufacturing and maintenance
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 ensures consistent color temperature and improved energy efficiency, extending the lifespan of lighting devices and reducing maintenance costs by maintaining desired color output and lumen levels, even in applications with varying light emitter performance.
Implementation Method 1
Light emitting diodes are well-known semiconductor devices that convert electrical current into light
Data Source
AI summary
Lighting devices comprising first, second and third strings of solid state lighting devices. One aspect further comprises means for supplying first fixed current through the first string, means for supplying second fixed current through the second string, and means for supplying current through the third string. In a second aspect, the first and second strings emit light within a specific area on a 1931 CIE Chromaticity Diagram, and the third string emits light of dominant wavelength 600-640 nm. A third aspect further comprises a power line and a power supply configured to supply a first and second fixed currents through the first and second strings, respectively, and supply a current to the third string. A method of making a lighting device, comprising measuring color output, adjusting current to first, second and/or third strings, and permanently setting currents to the first and second strings.