Electronic Pen Resonant Circuit for Paperless Handwriting Input
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Solution Overview
Problem
Existing handwriting input apparatuses using electronic pens with writing implement functions are costly and cumbersome, especially when paper is not needed, as they require complex configurations and produce eraser dust during mark removal.
Innovation Solution
An electronic pen with a resonant circuit formed by a coil and capacitor, coupled with a magnetic core, that uses electromagnetic inductive coupling to detect position and pressure on a magnetic sheet, allowing for handwriting input without a display panel and easy erasure without paper.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an electronic pen with a writing implement function is used to make handwriting input on paper, then the handwriting information can be detected through coordinate information, but the electronic pen configuration becomes complicated and the cost increases
Solution Approach 1:
The patent extracts the writing implement function from the electronic pen, separating it into a standalone component. The electronic pen now only contains the electromagnetic induction components (coil, magnetic core, capacitor) needed for coordinate detection, while the writing function is provided by a separate writing implement that makes contact with the paper surface
Solution Approach 2:
The patent creates a universal system where the electronic pen can work with any writing implement. The writing implement serves multiple purposes: it writes on paper and simultaneously serves as the detection element when it contacts the paper surface during handwriting input
2Reliability
If paper is used to keep handwriting input marks, then the marks are physically retained, but erasure becomes cumbersome and produces eraser dust
Solution Approach 1:
The patent replaces the mechanical erasure process (rubbing with eraser) with an electronic deletion process. Handwriting marks are stored as coordinate information in memory, allowing for clean electronic erasure without physical contact, thereby eliminating eraser dust generation while maintaining reliable mark retention
3Illumination intensity
If a display panel is added to display handwriting information, then visual recognition is improved, but production cost increases
Solution Approach 1:
The patent creates a visual copy of the handwriting information through the magnetic powder pattern on the paper surface. The magnetic poles attract magnetic powder to form a visible pattern that copies the handwriting trajectory, providing visual recognition without requiring an expensive display panel
Solution Approach 2:
The patent uses magnetic powder that changes its spatial distribution in response to magnetic fields. When the writing implement moves, magnetic poles generate magnetic fields that attract magnetic powder, creating visible patterns that change position and form the handwriting visual representation
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 solution reduces production costs, eliminates the need for paper, and prevents eraser dust, providing a more portable and efficient handwriting input system with accurate coordinate detection and easy erasure.
Implementation Method 1
exchanges a signal having a frequency corresponding to a resonance frequency of the resonant circuit with a position detection sensor through electromagnetic inductive coupling
Implementation Method 2
a capacitor that forms a resonant circuit together with the coil
Implementation Method 3
The core body includes a pen point portion and a tail portion forming magnetic poles on opposite sides of the core body
Data Source
AI summary
Disclosed is an electronic pen including a casing having openings, a coil, a magnetic core having the coil wound therearound, and having a through hole extending in an axial direction of the electronic pen, a capacitor that forms a resonant circuit together with the coil, and a core body inserted through the through hole of the magnetic core. The electronic pen exchanges a signal having a frequency corresponding to a resonance frequency of the resonant circuit with a position detection sensor through electromagnetic inductive coupling. The core body includes a pen point portion and a tail portion forming magnetic poles on opposite sides, the pen point portion protruding outwardly from one of the openings of the casing of the electronic pen and being located away from an end of the magnetic core on a pen-point side in the axial direction of the electronic pen.