Passive Stylus Pen Structure for Hover and Pressure Detection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing stylus pens face challenges in distinguishing hover, contact, and pen pressure motions, are costly due to complex internal structures, and suffer from performance variations due to assembly deviations.

Innovation Solution

A stylus pen design incorporating an inductor unit, elastic members, and a magnetic body that varies the distance between them based on core movement, allowing clear motion differentiation and reduced component count.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If an active stylus pen is used to provide additional functions (pen pressure, hovering, buttons), then the basic performance is improved, but the cost increases and a rechargeable battery is required

Engineering Contradiction:
Improveadditional functionsVSAvoidmanufacturing cost
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent extracts and removes the battery and electronic components from the stylus pen, retaining only the essential mechanical elements (core, elastic member, inductor unit) needed for basic stylus functionality. This extraction eliminates the need for power supply and complex electronics while maintaining core stylus operations.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent employs a passive stylus design without a rechargeable battery, effectively using a simpler, less expensive configuration that doesn't require power management infrastructure. This approach reduces manufacturing costs and eliminates battery replacement or recharging requirements.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Measurement precision

If an EMR sensor panel and EMR driving IC are added to achieve precise touch recognition, then the touch precision is improved, but the device thickness increases and manufacturing costs rise

Engineering Contradiction:
Improvetouch precisionVSAvoiddevice thickness
Core Design Contradiction:
Measurement precisionVSLength of stationary object

Solution Approach 1:

The patent makes the capacitance touch panel serve multiple functions: it detects both finger touches and stylus touches using the same hardware infrastructure. By utilizing the existing touch panel's self-capacitance and mutual-capacitance detection capabilities, the system achieves stylus precision without adding separate EMR sensing layers.

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

Solution Approach 2:

The patent creates an electromagnetic resonance phenomenon within the stylus pen itself using an inductor unit and magnetic body, rather than requiring an external EMR sensor panel. The stylus generates its own resonance signal that interacts with the capacitance touch panel, effectively copying the EMR detection capability in a different location (the pen rather than the panel).

Inventive Principle:
Principle #26Copying

3Power

If the resonance frequency is matched with the driving signal frequency to increase signal amplitude, then the signal transmission is improved, but the signal attenuation becomes extremely great making mass production difficult

Engineering Contradiction:
Improvesignal amplitudeVSAvoidsignal transmission stability
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The patent changes the physical parameters of the resonance circuit by adjusting the inductance value through varying the distance between the inductor unit and magnetic body. This parameter adjustment optimizes the resonance frequency to match the driving signal frequency, maximizing signal amplitude while maintaining transmission stability through controlled geometric relationships.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent utilizes mechanical vibration and resonance principles by creating an oscillating electromagnetic field through the interaction between the inductor unit and magnetic body. The periodic movement and positioning of these components generates a resonance signal that amplifies the output while maintaining stable transmission characteristics.

Inventive Principle:
Principle #18Mechanical vibration

4Measurement precision

If a pressure sensor is added to detect pen pressure, then the pressure detection capability is improved, but the manufacturing cost increases and precise measurement becomes difficult

Engineering Contradiction:
Improvepen pressure measurementVSAvoidmanufacturing cost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent makes the existing capacitance touch panel serve dual purposes: detecting both touch position and pen pressure. By analyzing the capacitance changes and resonance signal characteristics from the same touch panel infrastructure, the system extracts pressure information without requiring separate pressure sensing elements.

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

Solution Approach 2:

The patent implements feedback through the resonance circuit, where the output signal characteristics provide information about the pen pressure state. The resonance frequency and amplitude variations feed back to the controller, enabling pressure detection through signal analysis rather than direct mechanical sensing.

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 stylus pen effectively distinguishes hover, contact, and pen pressure motions while minimizing manufacturing costs and reducing performance variations from assembly deviations.

Implementation Method 1

a digitizer transmits an electromagnetic signal to the pen and then receives a resonance signal from the pen. In this digitizer, coils to which a current is induced by a magnetic signal are densely arranged

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

a first elastic member spaced apart from the inductor unit; a core that passes through the inductor unit and moves toward the first elastic member by an external force acting on one end thereof

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 3

a magnetic body disposed between the inductor unit and the first elastic member

Methodology Applied
Scientific EffectMagnetic field: Magnetic Field

Data Source

PatentEP4647879A2Stylus pen
Publication Date: 2025.11.12 HIDEEP INC
  • EP4647879A2 patent drawingFigure 1~2
  • EP4647879A2 patent drawingFigure 3A~3B
  • EP4647879A2 patent drawingFigure 4~5B

AI summary

The present invention relates to a stylus pen, and more particularly, to a stylus pen that is capable of clearly distinguishing a hover motion, a contact motion and a pen pressure motion, has a simple internal structure, easily detects pen pressure, has relatively little performance change caused by an assembly deviation, and reduces manufacturing costs. The stylus pen according to an embodiment of the present invention comprises: an inductor unit; a first elastic member disposed to be spaced from the inductor unit; a core which is disposed to penetrate the inductor unit, and which moves toward the first elastic member by means of an external force acting on one end thereof; and a magnetic body which is disposed between the inductor unit and the first elastic member, and of which the distance from the inductor unit changes in conjunction with that of the core, wherein the first elastic member is compressed by the movement of the core.