Touchscreen Defroster with Conductive Coating and Signal Filtering
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Solution Overview
Problem
Service terminals in retail environments experience frost formation on touchscreens due to temperature differences between indoor and outdoor conditions, leading to condensation and operational issues.
Innovation Solution
A touchscreen with a base material coated with electrically conductive layers that apply a base current to heat up and evaporate frost, while a controller filters input signals to determine touch locations, combining heating and touch detection functionality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a touchscreen is used in a service terminal exposed to outdoor temperature variations, then the touchscreen can be used for self-service operations, but frost and condensation form on the touchscreen due to temperature differences between indoor and outdoor environments
Solution Approach 1:
The patent applies a coating to the base material with specific electrical resistance properties (10^-6 to 10^-3 ohm-square) that enables the material to generate heat when voltage is applied. This parameter change in the coating's electrical properties allows the touchscreen to actively counteract frost and condensation by heating the surface, thus resolving the contradiction between outdoor usability and frost formation.
Solution Approach 2:
The patent converts the electrical energy that could be considered wasted heat into a beneficial function by using the conductive coating to generate controlled heat for frost prevention. The electrical current, which would normally just pass through the touchscreen, is now utilized to actively prevent condensation and frost, turning a potential harmful effect (heat generation) into a protective mechanism.
2Reliability
If a conductive coating is applied to the base material for heating, then frost can be prevented, but the base current may interfere with touch signal detection
Solution Approach 1:
The patent employs periodic or pulsed application of voltage to the conductive coating rather than continuous DC voltage. This periodic action allows the system to alternate between heating phases (for frost prevention) and sensing phases (for accurate touch detection), thereby resolving the contradiction between maintaining frost protection and ensuring measurement precision.
Solution Approach 2:
The patent uses feedback mechanisms where the controller monitors both the heating requirements and touch signals. By continuously adjusting the voltage applied to the conductive coating based on environmental conditions and touch detection needs, the system can maintain optimal balance between frost prevention and signal accuracy, resolving the contradiction through active control.
3Object-affected harmful factors
If voltage is applied to the conductive coating for heating, then the coating and base material heat up to evaporate condensation, but excessive heat may damage touchscreen components
Solution Approach 1:
The patent applies voltage partially or in controlled amounts rather than continuously at maximum level. By using pulsed voltage or adjusting the voltage level to be just sufficient for frost prevention, the system achieves the necessary heating effect without excessive temperature rise that could damage components, thus resolving the contradiction between effective condensation evaporation and temperature control.
Solution Approach 2:
The patent maintains continuous monitoring and adjustment of the heating function to ensure it operates continuously at the optimal level needed for frost prevention without overheating. This continuous adaptive control ensures the heating action remains useful for preventing condensation while preventing excessive temperature accumulation that could harm components.
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
Effectively prevents frost formation and maintains touchscreen functionality by ensuring continuous operation and accurate touch detection despite temperature variations.
Implementation Method 1
A base current is applied to the coating. As the base current flows through the coating, the coating and a portion of the base material heat up.
Implementation Method 2
The heating of the coating and the portion of the base material can work to evaporate any condensation or melt any frost that may form on touchscreen.
Implementation Method 3
The heating of the coating and the portion of the base material can work to evaporate any condensation or melt any frost that may form on touchscreen.
Data Source
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AI summary
Disclosed is a touchscreen (200). The touchscreen (200) can include a base material (204), a first coating (212), and a controller (206). The first coating (212) can be applied to the base material (204). The first coating (212) can be configured to generate an input signal. The controller (206) can be configured to apply a base signal to the first coating (212), and filter the input signal from a combined signal. The combined signal can include the input signal and the base signal.