Heatable Wired Laminated Glazing Temperature Control
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Solution Overview
Problem
Existing automotive heatable glazing systems struggle to quickly defrost or demist without exceeding the maximum safe temperature, which can damage the laminated glazing interlayer and is not effectively regulated by current methods.
Innovation Solution
A heated wired laminated glazing system with an embedded flat connector that includes a control circuit, an active regulation system, and a thermistor, allowing for precise control and regulation of the conductive wires' heating to maintain optimal temperature within safe limits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If voltage is increased or resistance is decreased to heat the glazing faster, then defrosting and demisting speed is improved, but the glazing temperature may exceed the maximum safe value and damage the interlayer
Solution Approach 1:
The patent implements a feedback control system using a thermistor to continuously monitor the glazing temperature and adjust the heating power accordingly. The control unit receives temperature signals from the thermistor and regulates the voltage to the conductive wires, ensuring the temperature remains within safe limits while optimizing defrosting speed. This closed-loop feedback mechanism resolves the contradiction by dynamically balancing heating intensity with temperature safety.
Solution Approach 2:
The patent changes the electrical parameters (voltage and power) dynamically based on temperature conditions. Instead of using fixed high voltage for rapid heating, the system adjusts voltage levels in real-time according to the measured temperature, allowing fast defrosting when cold but preventing overheating when approaching maximum safe temperature. This parameter adjustment strategy enables both high productivity and safety.
2Object-affected harmful factors
If a resistance is added to limit the voltage and temperature, then the interlayer is protected from damage, but the defrosting and demisting time is extended
Solution Approach 1:
The patent transitions from static resistance limiting to dynamic voltage control. The system starts with higher voltage for rapid heating when the glazing is cold, then dynamically reduces voltage as temperature approaches the maximum safe value. This dynamic adjustment allows aggressive heating initially (reducing time loss) while automatically throttling back to protect the interlayer, resolving the time-protection contradiction.
Solution Approach 2:
The heating system operates in periodic cycles with varying power levels. High-power heating phases are alternated with lower-power maintenance phases, controlled by the thermistor feedback. This periodic action allows rapid temperature increase during cold conditions while providing cooling intervals to prevent interlayer damage, optimizing both speed and protection.
3Productivity
If the heating voltage is increased to defrost faster, then the defrosting speed is improved, but the temperature regulation becomes inaccurate and may exceed maximum temperature
Solution Approach 1:
The patent employs precise feedback control through the thermistor to monitor temperature continuously. This feedback mechanism provides accurate temperature measurement even during high-power heating, allowing the control unit to make precise adjustments to maintain temperature within safe limits. The feedback loop ensures both high defrosting speed and accurate temperature regulation simultaneously.
Solution Approach 2:
The patent replaces simple mechanical resistance limiting with an electronic control system that uses electrical signals from the thermistor to regulate heating. This substitution of control mechanism enables more precise temperature monitoring and regulation, allowing high voltage heating while maintaining accurate temperature control through electronic feedback rather than fixed mechanical resistance.
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 system enables rapid defrosting and demisting while preventing the glazing from exceeding the maximum safe temperature, thus protecting the interlayer and ensuring effective optical sensor functionality.
Implementation Method 1
These wires are used to heat the windshield (resistance heating by Joules effect) for defrosting and defogging
Implementation Method 2
The flat connector further comprises, on its part at least partially embedded between the interlayer and the external glass sheet or the internal glass sheet, at least one thermistor
Data Source
AI summary
A heatable wired laminated glazing for a vehicle. The automotive glazing is designed to be placed in front of an optical sensor and includes an internal glass sheet facing the optical sensor, and an external glass sheet facing the outside of the vehicle. The glazing is laminated and features an interlayer, with conductive wires, laminating the internal glass sheet and the external glass sheet together. The glazing further features a flat connector, partially embedded, connected to the conductive wires, and extending along the internal glass sheet towards the face of the internal glass sheet opposite the interlayer. The flat connector includes a control circuit designed to control the embedded conductive wires an active regulation system, designed to be connected to a battery of the vehicle and at least one thermistor. The thermistor is connected to the control circuit through the flat connector.