LED Color Mixing Model Provisioning for Consistent Output
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge in creating uniform white light with LED-based lamps is due to variations in output intensity and peak wavelength among LEDs, leading to unpredictable color points and intensity, making it difficult to achieve consistent color rendering and correlated color temperature.
Innovation Solution
A color mixing model is developed that accounts for the brightness and color point of each LED channel, using an inverse solver algorithm to determine the necessary drive commands for each channel to produce a specific color point and flux output, incorporating empirical methods and spectral analysis to generate accurate color mixing models.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple LED channels with different color strings are used to create white light, then the versatility and color rendering capability are improved, but the variations in output intensity and peak wavelength among LEDs cause unpredictable color points and intensity
Solution Approach 1:
The patent changes the operational parameters (drive commands, flux levels) of each LED channel dynamically to compensate for manufacturing variations. By adjusting these parameters based on measured spectral properties, the system achieves consistent color points despite using LEDs with different peak wavelengths and intensities from the same bin.
Solution Approach 2:
The system incorporates feedback mechanisms where the actual spectral output of each LED channel is measured and used to adjust the drive commands. This closed-loop approach ensures that color rendering requirements are met by continuously monitoring and correcting for variations in LED performance.
2Ease of manufacture
If LEDs are binned by manufacturer according to output intensity and peak wavelength, then the ease of manufacture is improved, but the variations in luminosity per unit driving current remain too large
Solution Approach 1:
Instead of requiring tighter binning specifications, the patent changes the operational parameters of each LED channel to compensate for luminosity variations. The system measures the actual spectral power distribution and adjusts drive commands accordingly, achieving consistent color output without needing more precise manufacturing bins.
Solution Approach 2:
The system performs preliminary characterization of each LED channel's spectral properties during manufacturing or initial setup. This advance measurement allows the creation of a color mixing model that predicts the exact drive commands needed to achieve target color points, eliminating the need for post-assembly color adjustments.
3Adaptability or versatility
If the flux levels of multiple LED channels are adjusted to achieve specific color points, then the adaptability to different color temperatures is improved, but the color points routinely deviate due to variations in relative channel luminosity
Solution Approach 1:
The patent uses parameter changes in the spectral domain by measuring the actual spectral power distribution of each LED channel and adjusting the drive commands to compensate for luminosity variations. This ensures that when flux levels are adjusted for different color temperatures, the color points remain accurate despite manufacturing variations.
Solution Approach 2:
The system replaces manual or trial-and-error color adjustment methods with an automated computational approach. An inverse solver algorithm calculates the precise drive commands needed to achieve target color points, substituting mathematical computation for physical trial-and-error adjustment.
4Manufacturing precision
If a color mixing model is developed to account for brightness and color point of each LED channel, then the manufacturing precision of color output is improved, but the device complexity increases
Solution Approach 1:
The color mixing model is computed in advance during manufacturing or initial setup, before the lighting system is deployed. This preliminary computation creates a lookup table or stored model that can be quickly referenced during operation, avoiding complex real-time calculations and reducing operational device complexity.
Solution Approach 2:
The system creates a computational model (a digital copy) of the physical LED system's spectral properties. This virtual model allows for precise prediction and adjustment of color output without requiring complex physical measurement and adjustment mechanisms during operation.
Data Source
AI summary
Introduced here are techniques for generating color mixing models that enable a tunable lamp to mix the right amount of light from various color channels in order to properly produce colors. More specifically, a lamp controller can be configured to drive multiple light-emitting diode (LED) arrays based on corresponding color mixing models. One or more color mixing models can be provisioned into the memory of an LED array prior to usage. Storing the color mixing model in the LED array enables the lamp controller to update the color mixing model based on which LED array it is serving (i.e., the lamp controller and the LED array need not be a permanently matched set). Additionally or alternatively, the lamp controller may be configured to communicate with a network-accessible computer server system to access a historical color mixing database that includes set(s) of previously-recorded spectral properties and corresponding color mixing models.