Capacitive Sensor Switch With Display for Precise Finger Detection

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Solution Overview

Problem

Existing consignment systems lack a robust, easy-to-mount, and easy-to-operate input and output unit that can withstand industrial conditions and provide high sensitivity for finger detection while integrating a display for efficient operation.

Innovation Solution

A capacitive sensor switch with an integrated display unit, featuring a housing with a sensor assembly including a printed circuit board and a cover disk, utilizing capacitive and optical sensors for detection, and a 7-segment or matrix display for information display, designed to be waterproof and shock-resistant with a wireless interface for connectivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a mechanical check button is added to the display unit, then the reliability of input confirmation is improved, but the device complexity increases

Engineering Contradiction:
Improveinput confirmation reliabilityVSAvoidswitch structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical check button with a capacitive touch sensor that detects finger proximity through capacitive coupling. This electronic sensing mechanism eliminates moving mechanical parts while maintaining the ability to confirm user input, thereby improving reliability without increasing structural complexity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The capacitive sensor automatically detects and confirms user input through the natural capacitance of the human finger itself. The finger acts as both the input tool and the sensing element, eliminating the need for separate confirmation mechanisms like mechanical buttons.

Inventive Principle:
Principle #25Self-service

2Ease of operation

If the sensor surface is made larger to improve finger detection sensitivity, then the ease of operation is improved, but the measurement precision of finger position may deteriorate

Engineering Contradiction:
Improvefinger detection sensitivityVSAvoidfinger position precision
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent divides the sensor surface into multiple independent sensing zones or segments. Each zone can detect finger presence independently, allowing the overall sensor to maintain high sensitivity across a large area while still providing precise localization through the specific activated segment.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the sensor surface are assigned different functional characteristics. The sensor can apply different sensitivity thresholds or detection algorithms to different zones, optimizing both overall sensitivity and local position precision simultaneously.

Inventive Principle:
Principle #3Local quality

3Reliability

If a closed housing is used to protect the sensor switch from environmental conditions, then the reliability is improved, but the ease of manufacture deteriorates

Engineering Contradiction:
Improveenvironmental protectionVSAvoidassembly complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The housing serves multiple functions simultaneously: it provides environmental protection, acts as a mounting structure for the sensor components, and serves as the user interface surface. This multi-functionality reduces the number of separate parts needed, simplifying manufacturing despite the protective requirements.

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

Solution Approach 2:

The patent integrates the sensor assembly, display unit, and protective housing into a single unified structure. The sensor elements are mounted directly on the interior surface of the housing, eliminating the need for separate mounting brackets or assembly steps.

Inventive Principle:
Principle #5Merging (Combining)

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 provides a robust, reliable, and easy-to-use input and output unit capable of detecting fingers through capacitive and optical means, with a high-resolution display for efficient operation in industrial environments, allowing for simultaneous operation by multiple users and gesture recognition.

Implementation Method 1

The sensor circuit may detect the presence of a conductive object, for example a finger or a hand in close proximity to the sensor area. For detection an electric signal like a HF or RF signal may be fed into the sensor area and changes in signal level by capacitive coupling to the object may be evaluated.

Methodology Applied
Scientific EffectCapacitive coupling: Capacitance

Implementation Method 2

This display may be configured for different colors. This may allow several persons, each person with its individually assigned color, to simultaneously operate at the consignment system. The same applies for the LED outer ring, which is preferably based on RGB LEDs

Methodology Applied
Scientific EffectLight emitting diode effect: Light Emitting Diode

Data Source

PatentEP3596827B1Capacitive sensor switch with display
Publication Date: 2022.05.11 CAPTRON ELECTRONICS
  • EP3596827B1 patent drawingFigure 1~2
  • EP3596827B1 patent drawingFigure 3
  • EP3596827B1 patent drawingFigure 4~6

AI summary

A capacitive sensor switch comprises a housing and a sensor assembly. The sensor assembly further comprises a printed circuit board holding a sensor circuit with multiple LED and a cover disk on the printed circuit board and oriented towards the front side of the switch. The cover disk comprises an electrically conductive surface connected to the sensor circuit and a plurality of light channels for guiding the LED light.