Piezoelectric Touch Sensor Assembly for Static-Safe Displacement Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Touch sensor assemblies for household appliances face challenges in accurately sensing movement displacement during touch operations and are prone to damage from static electricity, particularly in refrigerator doors with complex exterior designs.
Innovation Solution
A touch sensor assembly comprising a sensor housing, a sensor PCB with copper coating, a metal plate, ceramic element, spacer, conductive foil, and a touch booster with a protrusive portion, which ensures accurate displacement sensing and separates the sensor controller from potential static electricity sources, enhancing recognition rates and preventing damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a touch sensor assembly is pressed against an exterior member to improve touch recognition, then the recognition rate is improved, but the sensor becomes vulnerable to static electricity damage
Solution Approach 1:
A conductive foil is introduced as an intermediary component between the touch sensor and the sensor controller. The conductive foil includes an inner guide line that applies electric current to the ceramic element and an outer guide line that applies electric current to the metal plate, serving as a protective barrier that prevents static electricity from reaching and damaging the sensor controller while maintaining effective touch sensing
2Shape
If the exterior member is designed with complex shapes for aesthetic purposes, then the appearance is improved, but accurate sensing of movement displacement becomes difficult
Solution Approach 1:
The touch sensor assembly is segmented into distinct functional components: a sensor housing disposed at the bottom surface of the exterior member, a sensor PCB with copper coating, a metal plate with ceramic element, a spacer with sensor hole, and a conductive foil with guide lines. This segmentation allows the sensing components to be isolated in a controlled environment within the sensor housing, enabling accurate movement displacement sensing regardless of the complex external shape of the exterior member
3Device complexity
If the sensor components are closely positioned to reduce assembly complexity, then manufacturing is simplified, but alignment precision and sensing accuracy deteriorate
Solution Approach 1:
A spacer is introduced as a positioning intermediary between the sensor PCB and the conductive foil. The spacer has a sensor hole formed at a position corresponding to the sensor, and it precisely positions the inner guide line and outer guide line of the conductive foil to apply electric current to the ceramic element and metal plate respectively. This intermediary component ensures accurate alignment and spacing of all sensor components, maintaining sensing accuracy while allowing for standardized manufacturing processes
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 improves touch recognition accuracy and prevents static electricity-induced damage, while maintaining a sleek exterior design by ensuring proper alignment and spacing of components, thus enhancing the user experience and appliance reliability.
Implementation Method 1
a touch sensor, the touch sensor including: a metal plate having a bottom surface in contact with the copper coating or film; and a ceramic element installed on a top surface of the metal plate
Data Source
AI summary
A touch sensor assembly may include a sensor housing disposed at a bottom surface of an exterior member of a household appliance in which an operation unit on which a user touches is formed; a sensor PCB which is provided inside the sensor housing and has a top surface on which a copper coating or film is formed; a touch sensor, the touch sensor including: a metal plate having a bottom surface in contact with the copper coating or film; and a ceramic element installed on a top surface of the metal plate; a spacer in which a sensor hole is formed at a position corresponding to the sensor and which has a bottom surface attached to a surface of the copper coating or film; a conductive foil attached to a top surface of the spacer and having a bottom surface on which an inner guide line which applies an electric current to the ceramic element and an outer guide line which applies an electric current to the metal plate are printed; and a contact portion formed to protrude from a top surface of the conductive foil corresponding to a position of the inner guide line.