Conductive Elastic Member for Capacitive Pen Core Retention

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Solution Overview

Problem

Conventional active capacitive pens face challenges in securely fixing core bodies with varying diameters and ensuring reliable electrical contact, especially when using materials like felt, due to the need for precise diameter matching and the risk of fiber bundles getting caught in metallic washers.

Innovation Solution

A position indicator with a conductive elastic member and core body holder that accommodates varying diameters through elastic fitting and secure retention, allowing for easy replacement and reliable electrical signal transmission via a signal transmitting unit and electric connecting member.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a metallic washer is used to fix the core body, then the electrical contact is improved, but the fiber bundles may get caught and the manufacturing precision deteriorates

Engineering Contradiction:
Improveelectrical contactVSAvoiddiameter matching
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent changes the material parameter from metallic to elastic material, and changes the contact mechanism from rigid clamping to elastic deformation. The elastic member deforms to accommodate the core body within a predetermined diameter range, providing both electrical contact and tolerance for diameter variations without fiber entanglement

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses an elastic member that functions as a flexible component to hold the core body. This elastic member can deform elastically to accommodate diameter variations while maintaining electrical contact, avoiding the fiber entanglement problem associated with rigid metallic washers

Inventive Principle:
Principle #30Flexible shells and thin films

2Manufacturing precision

If the core body diameter is made precise, then the electrical contact is improved, but the adaptability to different materials deteriorates

Engineering Contradiction:
Improvecore body diameterVSAvoidmaterial compatibility
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The elastic member is designed to accommodate core bodies made of different materials (felt, resin, metal) with varying diameters within a predetermined range. The elastic deformation capability provides universal compatibility across different material types while maintaining reliable electrical contact for each

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

3Reliability

If the contact area is increased, then the static electricity absorption is improved, but the fine operating input capability deteriorates

Engineering Contradiction:
Improvestatic electricity absorptionVSAvoidfine operating input
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The elastic member acts as an intermediary between the core body and the touch panel. It transmits static electricity from the core body to the user's hand through elastic deformation and contact, enabling fine operating input with a small contact area while maintaining effective static electricity absorption for capacitive detection

Inventive Principle:
Principle #24Intermediary (Mediator)

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 ensures secure fixation and electrical connectivity of core bodies with varying diameters, enabling precise operation and easy replacement, while preventing fiber bundles from getting caught, thus enhancing the pen's functionality and usability.

Implementation Method 1

a conductive elastic member including a through hole and a holding portion for holding and fixing the core body, the core body being detachably fitted into the conductive elastic member

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

an electric connecting member for establishing an electric connection between the core body holder and the signal transmitting unit. The signal transmitting unit is configured to supply a signal to the conductive core body through the electric connecting member, the core body holder, and the conductive elastic member

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP3168716B1Position indicator
Publication Date: 2020.09.09 WACOM CO LTD
  • EP3168716B1 patent drawingFigure 1
  • EP3168716B1 patent drawingFigure 2(A)~2(B)
  • EP3168716B1 patent drawingFigure 3(A)~3(B)

AI summary

To provide a position indicator including a retaining mechanism that can fix a core body securely and which can electrically transmit a signal from an internal circuit to the core body surely. The position indicator includes: a core body having conductivity; a conductive elastic member including a holding portion for holding and fixing the core body, the core body being detachably fitted into the conductive elastic member; a core body holder having conductivity, and fitted with the conductive elastic member to retain the core body fitted in the conductive elastic member; a signal transmitting unit; and an electric connecting member for establishing an electric connection between the core body holder and the signal transmitting unit. A signal from the signal transmitting unit is transmitted from the core body through the electric connecting member, the core body holder, and the conductive elastic member.