Capacitive Operation Device Electrode Segmentation for Input Accuracy

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Solution Overview

Problem

Existing electrostatic capacitance-based operation devices face issues with incorrect input sensing due to the position of the operator's body part, leading to unreliable operations, especially when the body part is near wiring lines or adjacent to intended input portions, and this problem worsens with higher pattern density.

Innovation Solution

The operation device incorporates a conductive member with electrodes and wiring portions arranged non-overlapping with pattern portions, including input determination electrodes and incorrect input determination electrodes, where the capacitance values are used to accurately determine intended operations by comparing them against set threshold values, reducing incorrect sensing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If electrostatic capacitance method is used for touch-sensitive sheet, then cost is reduced by using non-translucent conductive ink instead of ITO, but incorrect input sensing occurs when body part is near wiring lines or adjacent to intended input portions

Engineering Contradiction:

Improvemanufacturing costVSAvoidinput sensing accuracy

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The electrode is segmented into multiple independent detection regions: input determination electrodes (first and second) and incorrect input determination electrodes (third and fourth). Each electrode monitors a specific zone, allowing the system to distinguish between intentional input on a pattern portion and accidental proximity to wiring lines or adjacent areas, thereby maintaining reliability while using cost-effective conductive ink

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary evaluation mechanism that compares capacitance values from multiple electrodes against predetermined thresholds. This intermediary processing layer between the physical touch and the input recognition resolves the contradiction by filtering out false positives from accidental proximity while preserving genuine inputs, all without requiring expensive ITO materials

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If pattern density is increased to provide more functions, then functionality is improved, but incorrect sensing occurs more frequently

Engineering Contradiction:

Improvenumber of input functionsVSAvoidinput sensing accuracy

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

Each pattern portion has dedicated input determination electrodes and incorrect input determination electrodes assigned to it. This segmentation allows the system to handle high pattern density by providing individualized monitoring for each input zone, preventing cross-interference and maintaining reliability even as the number of functions increases

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies different electrode configurations and capacitance thresholds locally to each pattern portion based on its specific position and surrounding context. This local quality approach allows the system to adapt to varying densities and layouts, maintaining accurate input recognition across the entire panel regardless of overall pattern density

Inventive Principle:

Principle #3Local quality

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 configuration enables reliable input determination by prioritizing capacitance values from incorrect input determination electrodes, effectively reducing incorrect operations and improving input accuracy even in challenging conditions like vehicle operations.

Implementation Method 1

an electrostatic capacitance detection portion configured to detect electrostatic capacitance between the corresponding electrode and a specific body part such as a finger of an operator

Methodology Applied

Scientific EffectElectrostatic capacitance: Capacitance

Data Source

PatentEP2869170B1Operation device and vehicle operation device using the same

Publication Date: 2016.05.04 ALPS ALPINE CO LTD

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AI summary

An operation device (101) includes an operation panel (PN1) in which a plurality of pattern portions (11) to be operated by an operator are formed, a conductive member (12) including a plurality of electrodes (A3) arranged on a back surface side of the operation panel (PN1) and a plurality of wiring portions (A5), and an electrostatic capacitance detection portion (17) configured to detect electrostatic capacitances of the electrodes (A3), wherein the electrodes (A3) and the wiring portions (A5) are arranged at positions not overlapping with the pattern portions (11) when viewed in plan, an input determination electrode (AD4) close to a predetermined one of the pattern portions (11) and an incorrect input determination electrode (AG4) are included in the electrodes (A3), and the electrostatic capacitance detection portion (17) determines the presence or absence of an operation performed on the predetermined pattern portion (11), in accordance with a capacitance value of a change in electrostatic capacitance of each of the input determination electrode (AD4) and the incorrect input determination electrode (AG4). The operation device 101 is suitably applied to a vehicle operation device.