Keyboard Key Detection Coil Layout for Multi-Axis Position Sensing

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing keyboard devices require separate signal output units for detecting key displacement in the pressing and releasing direction and the front-rear direction, leading to inefficiencies and increased complexity.

Innovation Solution

A detection device that utilizes a single signal output unit to detect both the position of the key in the pressing and releasing direction and its displacement in the front-rear direction by employing a key-side conductive unit and a sensor unit with specific coil configurations, allowing for non-contact detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If a keyboard device has many keys arranged in a compact layout, then the device size is reduced, but it becomes difficult to detect which key is pressed when multiple keys are adjacent

Engineering Contradiction:
Improvekeyboard device sizeVSAvoidkey press detection accuracy
Core Design Contradiction:
Volume of moving objectVSMeasurement precision

Solution Approach 1:

The keyboard surface is divided into multiple detection regions, with each region corresponding to a specific key. This segmentation allows the detection device to identify which specific region receives the object, thereby determining which key is pressed, even when keys are closely arranged

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A detection object (such as a pointer or indicator) is introduced as an intermediary between the user input and the key detection system. The detection device tracks the position of this intermediary object to determine which key region is being activated, enabling precise detection in compact layouts

Inventive Principle:
Principle #24Intermediary (Mediator)

2Volume of moving object

If keys are arranged closely together to reduce device size, then portability is improved, but the complexity of the detection system increases

Engineering Contradiction:
Improvekeyboard device sizeVSAvoiddetection system complexity
Core Design Contradiction:
Volume of moving objectVSDevice complexity

Solution Approach 1:

The detection device uses a universal detection mechanism that can identify multiple different key regions using the same detection principles and components. This multi-functional approach allows accurate detection across compact layouts without requiring separate specialized detection systems for each key

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The detection system uses a simplified representation (detection object or indicator) that copies or represents the position of user input. This abstract representation simplifies the detection process by transforming complex multi-key positioning into tracking a single indicator's position across different regions

Inventive Principle:
Principle #26Copying

Data Source

PatentEP4152312B1Detection device for key operation of keyboard device and keyboard device
Publication Date: 2026.04.29 YAMAHA CORP
  • EP4152312B1 patent drawingFigure 1
  • EP4152312B1 patent drawingFigure 2
  • EP4152312B1 patent drawingFigure 3

AI summary

Provided is a detection device for the key operation of a keyboard device, said detection device having: a key-side conducting part provided to each of a plurality of keys; a circuit board provided so as to face the plurality of keys in the direction in which the plurality of keys are pressed and released; a plurality of sensor units which each have a coil, are provided to the circuit board so as to correspond to each of the keys, and output a signal which corresponds to distance from the key-side conducting part provided to the corresponding key; and a detection unit for detecting the displacement in the front-rear direction and the position in the pressing/releasing direction of the corresponding key, on the basis of the signal outputted by the sensor units.