Handwriting Input Device Pressure Detection Segmentation

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Solution Overview

Problem

Existing handwriting input devices with electronic pens incorrectly detect writing pressure even when no writing is performed on a paper sheet, leading to incorrect input data on the coordinate input device.

Innovation Solution

A handwriting input device with a mechanical pencil unit that includes a lead deliver portion with a buffer and a writing pressure detecting portion, where only a part of the unit moves with applied pressure, and a coordinate input device that fixes and detects the presence of the paper sheet to prevent incorrect data entry.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the whole writing unit retreats when receiving writing pressure, then the writing pressure can be detected, but incorrect input occurs when the lead does not project from the nib

Engineering Contradiction:
Improvewriting pressure detection accuracyVSAvoidinput data accuracy
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The writing unit is divided into two functional segments: the lead deliver portion (nib) that contacts the paper for writing, and the mechanical pencil unit body that houses the pressure detection mechanism. This segmentation allows the pressure detection to be coupled with the lead deliver portion's movement rather than the entire unit's movement, enabling accurate pressure detection only when the lead is actually projecting and contacting the paper.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The lead deliver portion acts as an intermediary element between the paper contact point and the pressure detection mechanism. When writing pressure is applied, the lead deliver portion moves in response to the pressure, and this movement is transmitted to the pressure detection mechanism. This intermediary mechanism ensures that pressure is only detected when the lead is actually in contact with the paper, preventing false detections.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If the writing pressure detecting portion is coupled with the mechanical pencil unit, then writing pressure can be detected, but the detecting portion moves when lead is not projecting

Engineering Contradiction:
Improvewriting pressure detection accuracyVSAvoidwriting operation reliability
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The pressure detection function is localized to the lead deliver portion rather than being distributed throughout the entire mechanical pencil unit. The detection mechanism is positioned to respond specifically to movements of the lead deliver portion, which only moves when the lead is projecting and contacting the paper. This local quality ensures that pressure detection is active only during actual writing conditions.

Inventive Principle:
Principle #3Local quality

3Adaptability or versatility

If no paper sheet is placed on the coordinate detection surface, then the device remains ready for use, but incorrect hand-written data is obtained

Engineering Contradiction:
Improvedevice readinessVSAvoiddata input accuracy
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The coordinate input device performs a preliminary detection action by detecting whether a paper sheet is placed on the coordinate detection surface before accepting handwriting input. This preliminary check ensures that the device only begins recording hand-written data when a paper sheet is present, preventing incorrect data from being obtained when no paper is available.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The device uses feedback from the paper sheet detection mechanism to control the handwriting data acquisition process. The detection result (paper present or absent) provides feedback that enables or disables the pressure detection and data recording functions, ensuring that handwriting data is only obtained under appropriate conditions when a paper sheet is actually present.

Inventive Principle:
Principle #23Feedback

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 reduces incorrect input by ensuring that hand-written data is only obtained when actual writing is performed on the paper sheet, improving consistency between paper-based handwriting and digital data.

Implementation Method 1

uses a coordinate detection method by an electromagnetic induction effect

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3508955B1Handwriting input apparatus
Publication Date: 2024.10.30 MITSUBISHI PENCIL CO LTD
  • EP3508955B1 patent drawingFigure 1
  • EP3508955B1 patent drawingFigure 2
  • EP3508955B1 patent drawingFigure 3A~3B

AI summary

To provide a handwriting input device that can reduce an incorrect input. A handwriting input device (1) of the present invention is a handwriting input device configured to obtain hand-written data of an electronic pen (3) on a coordinate detection surface (2a) of a coordinate input device (2) by an electromagnetic induction effect of the coordinate input device and the electronic pen. The electronic pen includes a first resonance circuit (40) including a coil, a capacitor, and a core, a mechanical pencil unit configured to perform writing on a paper sheet placed on the coordinate detection surface, and a writing pressure detecting portion (45) configured to detect a writing pressure such that a part of the mechanical pencil unit is pushed by receiving the writing pressure applied to a lead projecting from a distal end of the mechanical pencil unit. The detection of the writing pressure causes the coordinate input device to obtain the hand-written data corresponding to a handwriting on the paper sheet while writing is performed on the paper sheet with the electronic pen.