LED Color Locus Stabilization via Temperature Calibration

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Solution Overview

Problem

Conventional lighting systems using three individual colors are unsatisfactory in terms of lighting characteristics, and require complex and expensive optical sensors to adjust and stabilize the color locus, especially due to temperature effects in LEDs.

Innovation Solution

A method to set a color locus of a lighting system without optical sensors, by determining the temperature and brightness of light sources based on calibration data, converting these into an actual color locus, and iteratively adjusting the light sources to reach a target color locus, thereby compensating for temperature-induced fluctuations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If optical sensors are used to monitor and adjust the color location of light sources, then the color locus can be accurately stabilized, but the system becomes complex and expensive

Engineering Contradiction:
Improvecolor location accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces optical sensors (optical measurement system) with a temperature measurement system. Instead of using complex optical sensors to detect color location deviations, the invention measures the temperature of light sources (especially LEDs) and uses predetermined calibration data to determine brightness and wavelength based on temperature. This substitution eliminates the need for expensive optical sensors while maintaining color locus stabilization capability.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent creates a mathematical model that copies the relationship between temperature and color characteristics (brightness and wavelength) through predetermined calibration data. This model allows the system to predict color location based on temperature measurements, effectively creating a virtual representation of color characteristics without direct optical measurement.

Inventive Principle:
Principle #26Copying

2Adaptability or versatility

If more than three individual colors are used in lighting systems, then lighting characteristics improve, but the system becomes more complex

Engineering Contradiction:
Improvelighting characteristicsVSAvoidsystem complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent uses parameter changes (temperature) to control the brightness and wavelength of multiple light sources. By measuring temperature and using calibration data to determine the corresponding brightness and wavelength parameters, the system can adjust multiple light sources to achieve desired lighting characteristics without requiring complex real-time control algorithms for each individual color channel.

Inventive Principle:
Principle #35Parameter changes

3Stability of the object's composition

If temperature effects are compensated for in real-time, then color consistency is maintained, but measurement and control complexity increases

Engineering Contradiction:
Improvecolor consistencyVSAvoidcontrol complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent performs preliminary action by creating predetermined calibration data that establishes the relationship between temperature and color characteristics (brightness and wavelength) before actual operation. This calibration data is stored and used during operation to directly determine color parameters from temperature measurements, eliminating the need for complex real-time calculation and control algorithms.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses the temperature measurement itself to determine the color characteristics. The temperature data serves dual purposes: it indicates the thermal state of the light source and, through the calibration model, directly provides the brightness and wavelength information. This self-service approach eliminates the need for separate color measurement and control systems.

Inventive Principle:
Principle #25Self-service

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 approach allows for efficient compensation of temperature effects in lighting modules, stabilizing the color locus without the need for expensive optical sensors, enabling user-defined color tone and brightness settings while maintaining color consistency.

Implementation Method 1

wherein the temperature of the at least one light source is determined

Methodology Applied
Scientific EffectThermal radiation: Thermal Radiation

Implementation Method 2

a temperature of the light module is additionally determined

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

Different light sources, in particular light-emitting diodes and/or combinations of light-emitting diodes of different wavelengths

Methodology Applied
Scientific EffectLight-emitting diode effect: Light Emitting Diode

Implementation Method 4

light-emitting diodes of different wavelengths are used as light sources

Methodology Applied
Scientific EffectElectroluminescence: Electroluminescence

Implementation Method 5

the brightness and the wavelength of the at least one light source are converted into an actual color locus

Methodology Applied
Scientific EffectElectrical signal processing:

Data Source

PatentEP2223568B1Method and arrangement for adjusting a color location, and illumination system
Publication Date: 2019.06.19 OSRAM GMBH
  • EP2223568B1 patent drawingFigure 1
  • EP2223568B1 patent drawingFigure 2
  • EP2223568B1 patent drawingFigure 3

AI summary

The invention relates to a method and an arrangement for setting a color location, wherein a temperature is determined, and the color location of the illumination source is set as a function of the temperature that is determined. The invention further provides an illumination system comprising an arrangement for setting the color location.