Appliance with a control panel
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Solution Overview
Problem
Capacitive touch sensors in control panels for appliances face challenges in marking or illuminating the dielectric panel to inform users of sensor locations, leading to increased cost and complexity due to the use of multiple printed circuit boards.
Innovation Solution
A control panel design featuring a dielectric substrate with a capacitive sensor and a light emitter on a single printed circuit board, where conductive bodies provide electrical coupling and a light guide reflects light to illuminate the front surface, allowing for user input detection and function indicator illumination without additional PCBs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If separate PCBs are used for capacitive touch sensors and light emitting diodes, then the control panel can provide both sensing and illumination functions, but the device complexity and manufacturing cost increase
Solution Approach 1:
The patent combines the capacitive touch sensor and light emitting diode onto a single printed circuit board, eliminating the need for separate PCBs. The sensor and LED are positioned on the same board with the LED between conductive bodies, integrating both sensing and illumination functions into one unified structure, thereby reducing device complexity and manufacturing cost while maintaining full functionality.
2Shape
If a dielectric panel is used to provide a clean cosmetic appearance, then the aesthetic quality improves, but the ability to mark or illuminate sensor locations becomes challenging
Solution Approach 1:
The patent uses the dielectric panel as an intermediary element that maintains its clean cosmetic appearance while enabling sensor location visibility. The capacitive sensor and light emitting diode are positioned behind the dielectric panel, which provides a smooth outer surface for aesthetic purposes. The LED illuminates through the dielectric panel to indicate sensor locations, and the conductive bodies extend through the dielectric to detect touches, thus the dielectric panel mediates between aesthetic requirements and functional visibility needs.
3Shape
If capacitive touch sensors are positioned behind a dielectric panel, then the control panel maintains a smooth surface, but the electrical coupling between the sensor and user touch becomes weaker
Solution Approach 1:
The patent creates an electrical pathway that effectively copies or extends the conductive connection through the dielectric barrier. The conductive bodies extend from the PCB through the dielectric panel to the front surface, creating a continuous electrical coupling path that mimics direct contact. This allows the sensor to detect user touches through the dielectric panel with sufficient sensitivity while maintaining the smooth surface aesthetic, as the conductive bodies replicate the electrical connection despite the dielectric separation.
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 design reduces complexity and cost by integrating lighting and capacitive sensing on a single PCB, providing a clean aesthetic and user-friendly operation by backlighting touch points without the need for multiple PCBs.
Implementation Method 1
capacitive touch sensors can detect a change in capacitance when the user touches the control panel
Implementation Method 2
light emitting diodes mounted on the other of the PCBs
Implementation Method 3
The capacitive sensor includes a pair of conductive bodies that extend between the dielectric substrate and the printed circuit board. Each conductive body of the pair of conductive bodies provides a conductive electrical coupling between the dielectric substrate and a respective electrode of the capacitive sensor.
Data Source
AI summary
An appliance includes a control panel with a dielectric substrate. A printed circuit board is spaced from a back surface of the dielectric substrate. A light emitter and a capacitive sensor are positioned on the printed circuit board. The capacitive sensor includes a pair of conductive bodies that extend between the dielectric substrate and the printed circuit board. The dielectric substrate is positioned on a cabinet such that the capacitive sensor is triggered when a user touches a front surface of the dielectric substrate and such that an appliance function indicator is illuminated at the front surface of the dielectric substrate during operation of the light emitter.