Inductive Keystroke Detection for Wear-Free Variable Key Input
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Solution Overview
Problem
Conventional mechanical key modules suffer from material wear, leading to incorrect switching and limited detection options, as they provide only one switching point per actuation, making them unsuitable for varied applications like gaming that require variable signal control.
Innovation Solution
A contactless key press detection apparatus using an inductive resonance circuit with a primary coil and a short-circuited secondary coil, allowing for adjustable switching points and variable signal output through changes in inductive coupling, enabling continuous or stepped signal processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional mechanical contact surfaces are used for key detection, then the structure is simple and easy to manufacture, but material wear occurs leading to incorrect switching and limited service life
Solution Approach 1:
The patent replaces the mechanical contact-based key detection system with an inductive detection system using primary and secondary coils. The movement element with conductive material encloses a continuous recess forming a short-circuited secondary coil that inductively couples with a stationary primary coil, eliminating mechanical contact and material wear while maintaining detection functionality.
Solution Approach 2:
The patent introduces an inductive coupling mechanism as an intermediary between the key actuation and signal generation. The secondary coil formed by the conductive material with continuous recess acts as an intermediary that transfers movement information to the primary coil through electromagnetic induction, avoiding direct mechanical contact.
2Adaptability or versatility
If conventional mechanical key modules are used, then the structure is simple, but only one switching point is provided per actuation, limiting detection options for varied applications
Solution Approach 1:
The patent makes the switching point adjustable by varying the position where the inductive coupling threshold is reached. The continuous recess in the conductive material can be positioned at different locations along the movement path, allowing the switching point to be dynamically adjusted based on application requirements while maintaining a relatively simple overall structure.
3Adaptability or versatility
If conventional mechanical key modules are used, then the structure is simple, but no variable signal output is possible, limiting applications requiring joystick function
Solution Approach 1:
The patent enables variable signal output by changing the inductive coupling parameter. As the key moves, the degree of coupling between the primary and secondary coils varies continuously, allowing the output signal to reflect the position or velocity of the key actuation. This provides joystick functionality and variable signal processing options without requiring complex additional structures.
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 apparatus extends the service life of key modules with constant switching quality, offers adjustable switching points, and supports variable signal output, enhancing detection and processing options for diverse applications without mechanical wear issues.
Implementation Method 1
The primary coil and the at least one secondary coil are inductively coupled to one another
Implementation Method 2
an electrical resonance circuit with at least one capacitor and with at least one primary coil with one or more coil windings
Data Source
AI summary
The invention relates to an apparatus for detecting a key press comprising a circuit substrate, a key module with a key cap and a movement mechanism, and a device for detecting the movement of the key cap, wherein the movement mechanism has at least one movement element wherein this device comprises an electrical resonance circuit with at least one capacitor and with a primary coil and comprises a secondary coil wherein the device for detecting the movement of the key cap comprises a measuring device for detecting and/or processing at least one physical variable of the electrical resonance circuit, which variable changes during the movement of the key cap, and outputs at least one electrical signal that is dependent on the change in the physical variable.The invention also relates to a keyboard comprising one or more such apparatuses and to a method for detecting a key press.