Vehicle Lamp LED Current Control Across Temperature Ranges
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vehicle lamps, particularly those using light-emitting diodes (LEDs), struggle to optimally balance luminous flux and lifetime in relation to temperature variations, failing to meet both legal light values and thermal thresholds in a cost-effective manner.
Innovation Solution
An illuminated body for vehicle lamps that includes a carrier body with light sources, a sensor unit for temperature detection, and a control unit to adjust the electric current of the light sources based on detected temperatures using distinct control curves for different temperature ranges, ensuring compliance with specified luminous flux and thermal limits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the electric current of the light source is increased to maintain luminous flux at low temperatures, then the luminous flux is improved, but the lifetime of the light-emitting diode deteriorates due to excessive current stress
Solution Approach 1:
The patent implements dynamic current adjustment based on temperature conditions. The control unit continuously monitors temperature and adapts the electric current to the light source according to a stored control curve, transitioning from static to dynamic operation to optimize both luminous flux and lifetime under varying thermal conditions.
Solution Approach 2:
The patent changes the operating parameters (electric current) based on temperature conditions. By storing multiple control curves with different current-temperature relationships and selecting the appropriate curve based on ambient temperature, the system optimizes the balance between luminous flux and component lifetime for each operating condition.
2Duration of action of stationary object
If the electric current of the light source is decreased to extend lifetime at high temperatures, then the lifetime is improved, but the luminous flux deteriorates and may not meet legal requirements
Solution Approach 1:
The system dynamically adjusts current based on real-time temperature feedback. At elevated temperatures, the control unit automatically reduces current according to the control curve to prevent thermal runaway and extend lifetime, while at lower temperatures it increases current to maintain required luminous flux levels.
Solution Approach 2:
The patent employs a feedback mechanism where the control unit continuously monitors temperature and adjusts the electric current accordingly. This closed-loop control ensures that the light source operates within safe parameters while maintaining compliance with luminous flux requirements across different operating conditions.
3Device complexity
If a single control curve is used for all temperature ranges, then the device complexity is reduced, but the manufacturing precision of luminous flux across temperature ranges deteriorates
Solution Approach 1:
The patent segments the temperature operating range into multiple intervals, each with its own optimized control curve. This segmentation allows precise control of luminous flux for different thermal conditions while keeping each individual control curve relatively simple, balancing complexity and precision requirements.
Solution Approach 2:
The control unit is designed with universal functionality to store and select from multiple control curves. This multi-functionality allows a single device to adapt to various temperature conditions and luminous flux requirements without requiring separate control systems for each temperature range.
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 allows for precise and cost-effective management of luminous flux across varying temperatures, ensuring compliance with legal light values and extending the lifetime of the light sources by preventing overheating.
Implementation Method 1
at least one sensor unit for detecting a temperature of the illuminated body
Implementation Method 2
at least one light source arranged on the carrier body for emitting light
Data Source
AI summary
An illuminated body is provided for a lamp of a vehicle, and includes at least one carrier body, at least one light source arranged on the carrier body, at least one sensor unit for detecting a temperature, and at least one control unit for setting an electric current of the light source for emitting the light of the light source as a function of the temperature detected by the sensor unit. The control unit is at least designed to set for a first temperature range (B1) the electric current of the light source as a function of the temperature detected by the sensor unit on the basis of a first control section (A1) of a control curve (C1) and for a second temperature range (B2) on the basis of a second control section (A2) of the control curve (C1).