Capacitive Switch Circuit With Reflective Screen for Hidden Components
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Capacitive switching devices struggle to maintain aesthetic appeal while ensuring operational visibility and preventing the exposure of internal electrical components, as existing solutions either compromise capacitive functionality or create unappealing black button environments.
Innovation Solution
A thin-walled reflective screen with high surface resistance is integrated into the device, allowing light waves to be partially reflected, refracted, or scattered, creating a metallic appearance while maintaining capacitive functionality, and opaque absorption layers are used to hide internal components, with independent lighting for each button and optional display integration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a reflective film or substrate is applied to the inside of the cover plate to prevent light reflections, then disruptive light reflections are reduced, but the visual impression becomes aesthetically unappealing with black surfaces around buttons
Solution Approach 1:
The patent applies a reflective film or substrate with specific optical properties to the inside of the cover plate that creates a metallic visual appearance. This film reflects light in a way that produces a chrome or metallic effect, transforming the aesthetic appearance from unappealing black surfaces to visually attractive metallic surfaces while still preventing disruptive light reflections.
2Illumination intensity
If the cover plate is made transparent to allow lighting elements to illuminate buttons, then button visibility and operational feedback are improved, but internal electrical components become visible from the outside
Solution Approach 1:
The patent implements local quality by making the cover plate selectively transparent or translucent only in specific regions corresponding to button locations, while maintaining opacity in other regions. This allows lighting elements to effectively illuminate buttons for operational feedback while preventing the visibility of internal electrical components from the outside.
3Shape
If a reflective screen with metallic appearance is integrated into the cover plate, then aesthetic appearance is improved, but capacitive switching functionality may be compromised
Solution Approach 1:
The patent employs a thin reflective film or substrate integrated into the cover plate structure. This thin film provides the desired metallic appearance while maintaining sufficient transparency to capacitive fields, ensuring that the capacitive switching functionality between the sensor surface and cover plate is not compromised. The thinness of the film allows capacitance fields to pass through while still providing optical reflection for aesthetic purposes.
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 effectively conceals internal components, maintains capacitive switching integrity, and provides a visually appealing metallic appearance, allowing for clear button operation and circuit symbol display without compromising functionality.
Implementation Method 1
causing the light waves incident on the reflector screen from the outside to be partially reflected
Implementation Method 2
refracted
Implementation Method 3
scattered
Implementation Method 4
the sensor surface changes, the capacitance field of the respective sensor surface changes
Implementation Method 5
an opaque absorption layer is applied to the top and/or bottom of the reflective screen
Data Source
Figure 1~2
AI summary
In a capacitive switching device (1) for generating at least one switching signal that can be evaluated electrically, by means of which an electrical device, for example a telephone, a machine tool, a refrigerator or the like, can be operated manually, with a cover plate (4) arranged in a housing (3), which is made of a transparent or semi-transparent material, in particular glass or a plastic, and can be seen through the at least one button (5) and can be operated from the outside, with at least one sensor surface (6) that generates a capacitance field and consists of an electrically conductive material and which is applied to a carrier or printed circuit board (7) provided inside the housing (3) and which is aligned flush with the respective button (5), with at least one lighting means ( 8), in particular an LED, through the light waves (10) in one on the cover plate (4) directed beam path (9) and through which the respective button (5) is illuminated and with a voltage source (14) for energizing the sensor surface and the lighting means, on the one hand the switching function, i.e. the assignment between the buttons 5 and their operability from the outside without further ado and on the other hand, an optical effect arise during operation that suggests to the user that the switching symbols are arranged on a metal layer. This object is achieved in that a thin-walled reflection screen (11) is arranged in the beam path (9) of the respective light wave (10) of the lighting means (8), that the light waves ( 10) pass through it to the outside and that the light waves incident from the outside onto the reflection screen (11) are partially reflected, refracted and/or scattered by them.