LED Headlight Color Stabilization via Temperature Compensation
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Solution Overview
Problem
LED headlights struggle to maintain consistent color temperature and color rendering properties across varying ambient temperatures, leading to suboptimal performance in film and video recordings, especially when using LEDs with narrow-band spectra, which can result in unacceptable color casts and reduced luminous efficacy.
Innovation Solution
The method involves calibrating LED headlight luminous flux components at initial and ambient temperatures using Gaussian distribution approximations to recalculate emission spectra, allowing for precise adjustment of color temperature and color location independently of temperature changes, utilizing a single temperature sensor and pulse width modulation for control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If narrow-band LED spectra are used to achieve precise color location, then color rendering index deteriorates
Solution Approach 1:
The patent combines multiple LED types with different spectral characteristics (narrow-band LEDs for precise color location and broadband LEDs for good color rendering) into a single illumination system. The control unit calculates and adjusts the luminous flux components of each LED type to achieve both precise color location and acceptable color rendering index simultaneously.
2Illumination intensity
If LED luminous flux is increased to improve brightness, then temperature increases causing color stability to deteriorate
Solution Approach 1:
The patent incorporates a temperature sensor that continuously monitors the temperature of the LED illumination device. The control unit receives this temperature information and adjusts the luminous flux components of individual LEDs to compensate for temperature-induced color shifts, thereby maintaining stable color properties even at high brightness levels.
3Adaptability or versatility
If multiple LED colors are mixed to achieve desired color temperature, then device complexity increases
Solution Approach 1:
The patent controls the color temperature by adjusting the luminous flux parameters of individual LEDs with different spectral characteristics. The control unit calculates the optimal luminous flux distribution based on the desired color temperature and adjusts each LED's output accordingly, enabling flexible color temperature adjustment without requiring complex mechanical or optical mechanisms.
4Stability of the object's composition
If temperature compensation is implemented to maintain color stability, then control time increases
Solution Approach 1:
The patent stores pre-calculated luminous flux component data for different temperature conditions in a database. When temperature changes are detected, the control unit can quickly retrieve and apply the appropriate compensation parameters without performing complex real-time calculations, thereby maintaining color stability with minimal control time.
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 ensures stable color properties, maintaining desired color temperature and rendering index with minimal production and control time, reducing computational effort and errors, and achieving precise color stabilization in LED headlights.
Implementation Method 1
with one temperature sensor arranged in the housing of the LED headlight
Implementation Method 2
The method involves calibrating LED headlight luminous flux components at initial and ambient temperatures using Gaussian distribution approximations to recalculate emission spectra
Implementation Method 3
utilizing a single temperature sensor and pulse width modulation for control
Implementation Method 4
using Gaussian distribution approximations to recalculate emission spectra
Data Source
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AI summary
The invention relates to a method for the temperature-dependent adjustment of the color or photometric properties of an LED illumination device having LEDs or LED color groups emitting light of different colors or wavelengths, emitting light of the same color or wavelength within a color group, the luminous flux portion thereof determining the light color, color temperature, and/or the color location of the light mixture emitted by the LED illumination device, characterized by measurement of the board temperature and/or junction temperature of at least one LED, determination of at least one temperature-dependent value determining the emission spectra E(?) of the variously colored LEDs as a function of the wavelength of the variously colored LEDs from calibration data stored for each of the variously colored LEDs, determination of the luminous flux portions of the variously colored LEDs for a light mixture comprising a prescribed light color, color temperature, and/or color location at the measured temperature as a function of the at least one temperature-dependent value determined, and adjustment of the determined luminous flux portions at the variously colored LEDs.