Electronic Pen Magnetic Core Projection for Sensor Coupling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge is to create a thinner electronic pen that maintains strong magnetic coupling with a position detection device, as reducing the thickness of the pen leads to a decrease in magnetic flux linkage due to the restricted winding thickness of the coil and reduced ferrite core thickness.
Innovation Solution
The electronic pen features a tubular housing with a magnetic core that has a coil non-wound portion at the pen tip, allowing the pen tip and part of the magnetic core to project outside, reducing the distance to the sensor and enhancing magnetic coupling, even when the pen is thinner.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the thickness of the electronic pen is reduced, then the pen becomes thinner and more portable, but the magnetic flux linkage decreases due to restricted winding thickness of the coil and reduced ferrite core thickness
Solution Approach 1:
The magnetic core extends in the axial direction beyond the coil wound portion, creating a projection that protrudes from the pen tip. This dimensional extension allows the magnetic core to approach the sensor surface more closely, compensating for the reduced thickness and maintaining strong magnetic coupling despite the overall thinner pen structure.
Solution Approach 2:
The magnetic core has different functional zones: a coil-wound portion for electromagnetic induction and a coil-nonwound portion that projects outward for enhanced magnetic coupling with the sensor. This local differentiation allows each portion to optimize its function, with the projecting magnetic core tip providing concentrated magnetic field interaction.
2Length of moving object
If the winding thickness of the coil is restricted to make the pen thinner, then the pen becomes more compact, but the magnetic flux linkage capability is reduced
Solution Approach 1:
Instead of increasing coil winding thickness, the solution extends the magnetic core in the axial direction beyond the coil portion. This creates a projecting magnetic tip that approaches the sensor surface, maintaining strong magnetic coupling through reduced air gap rather than through increased winding thickness.
Solution Approach 2:
The projecting magnetic core portion acts as an intermediary that bridges the gap between the coil and the sensor surface. It concentrates and directs the magnetic field from the coil toward the sensor, maintaining effective magnetic coupling even with restricted winding thickness.
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 strengthens the magnetic coupling between the electronic pen and the sensor, enabling effective position detection with high sensitivity, while maintaining compatibility with commercially available ballpoint pens.
Implementation Method 1
a magnetic core provided at an end of the core body that is opposite the end of the core body that serves as the pen tip and having a coil wound thereon
Implementation Method 2
part of the coil non-wound portion of the magnetic core projects from the opening to outside of the housing... strengthens the magnetic coupling between the electronic pen and the sensor
Data Source
AI summary
An electronic pen has a tubular housing which has an opening provided at one end in an axial direction of the housing and is closed at another end thereof, and has at least one electronic pen main body accommodated in the tubular housing. The electronic pen main body includes a core body having an end in the axial direction of the housing that serves as a pen tip, and a magnetic core provided at an end of core body that is opposite to the end of the core body that serves as the pen tip and having a coil wound thereon. In operation, the end of the core body that serves as the pen tip projects from the opening of the housing to outside of the housing, and part of the magnetic core projects from the opening of the housing to outside of the housing.