Electromagnetic Pen Assembly With Elastic Buffering for Size Consistency

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Solution Overview

Problem

The existing electromagnetic pens with a distance relationship structure between two iron cores face issues of size inconsistency due to manufacturing errors, leading to deviations from standard sizes, which hinders mass production and results in potential mechanical damage and reduced service life.

Innovation Solution

The electromagnetic pen features a housing with a front and rear housing, a pen body including a pen core, first and second iron cores, a PCBA circuit board, and an elastic structure, where the pen core passes through the first iron core to drive the second iron core, and a clamping slot and screw post ensure tight assembly, while an elastic structure like a silicone ring addresses manufacturing errors and provides buffering.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a distance relationship structure of two iron cores is used to change inductance value, then the electromagnetic pen can achieve frequency change and pressure sensing, but manufacturing errors of multiple parts lead to size inconsistency

Engineering Contradiction:
Improvesize consistencyVSAvoidstructure complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent merges the two iron cores into a single integrated iron core structure with a groove, eliminating the need for separate assembly of multiple parts. This integration directly addresses the size inconsistency problem by reducing the number of components that could contribute manufacturing errors, while maintaining the inductance change functionality through the groove mechanism.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The integrated iron core is segmented into different functional regions: a first portion for magnetic flux conduction and a second portion with a groove for inductance adjustment. This segmentation allows the single structure to perform multiple functions that previously required separate components, achieving both simplicity and functional complexity.

Inventive Principle:
Principle #1Segmentation

2Length of moving object

If coil is wound on solenoid to change inductance, then inductance value can be adjusted, but diameter of pen becomes larger

Engineering Contradiction:
Improvepen diameterVSAvoidinductance adjustment capability
Core Design Contradiction:
Length of moving objectVSManufacturing precision

Solution Approach 1:

Instead of winding the coil around a solenoid to achieve inductance adjustment, the patent inverts the approach by placing the coil on a flat PCB and using an iron core with a groove that moves relative to the coil. This inversion maintains the inductance adjustment capability while significantly reducing the pen diameter.

Inventive Principle:
Principle #13The other way round (Inversion)

3Loss of energy

If coil is wound on solenoid, then inductance can be changed, but distance between coil and iron core increases causing energy loss

Engineering Contradiction:
Improveenergy lossVSAvoidinductance adjustment capability
Core Design Contradiction:
Loss of energyVSManufacturing precision

Solution Approach 1:

The patent merges the coil and iron core into a closely integrated structure where the iron core sits directly on the PCB near the coil, eliminating the distance problem. The groove in the iron core allows for inductance adjustment without increasing the distance between the coil and iron core, thus minimizing energy loss while maintaining adjustability.

Inventive Principle:
Principle #5Merging (Combining)

4Adaptability or versatility

If multiple parts are assembled to form electromagnetic pen, then functional components can be integrated, but size inconsistency occurs during assembly and production

Engineering Contradiction:
Improvefunctional integrationVSAvoidsize consistency
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent combines multiple functional components into integrated structures: the iron core integrates magnetic flux conduction and inductance adjustment functions, the PCB integrates coil mounting and circuit functions, and the housing integrates structural support and shielding. This merging reduces the number of separate parts that could contribute to size inconsistency while maintaining functional versatility.

Inventive Principle:
Principle #5Merging (Combining)

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 design ensures size consistency, facilitates batch production, reduces mechanical damage, and extends the pen's service life by eliminating axial errors and providing effective force feedback.

Implementation Method 1

a coil is wound outside the first iron core... An antenna board may emit a frequency to charge the pen, when the antenna board stops emitting, the pen may be changed from receiving energy to emitting energy

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

an elastic structure with a ring shape is disposed between the PCBA circuit board and the iron core holder... an elastic structure like a silicone ring addresses manufacturing errors and provides buffering

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3855293B1Electromagnetic pen
Publication Date: 2023.11.08 HANVON UGEE TECH CO LTD
  • EP3855293B1 patent drawingFigure 1~4

AI summary

Disclosed is an electromagnetic pen, including a housing and a pen body located in the housing, the housing includes a front housing and a rear housing, the pen body includes a pen core, a first iron core, an iron core holder, and a PCBA circuit board, a coil is wound outside the first iron core, the first iron core is fixed at an end of the iron core holder close to a pen tip of the pen core, a second iron core is disposed in the iron core holder, and the pen core is configured to pass through a center of the first iron core, and then drive the second iron core to move; and an elastic structure is disposed between the PCBA circuit board and the iron core holder, a clamping slot is disposed on the PCBA circuit board, and an end portion matched with the clamping slot is disposed on the rear housing. In the invention, the elastic structure is additionally disposed between the iron core holder of the front housing and the PCBA circuit board, and an actual size of an electromagnetic pen in delivery is equal to a standard size by an elastic margin of the elastic structure, thereby being conductive to batch production, reducing a probability that parts are damaged due to mechanical shock or wear at the same time, and prolonging a service life of the electromagnetic pen. The invention can be widely used in the field of information input devices.