Bidirectional Active Stylus Electrode Positioning for Signal Reception

Solution Overview

Problem

Conventional active styluses face issues with poor signal receiving performance due to the receiving electrode being too far from the touch pad, susceptibility to noise interference, and complex assembly processes that increase the risk of errors and short circuits.

Innovation Solution

A bidirectional active stylus design with a receiving electrode positioned at the tip portion, a first emitting electrode closer to the cone portion, and a second emitting electrode farther away, arranged along a straight line, with the receiving electrode and first emitting electrode integrated for improved signal reception and simplified assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the receiving electrode is disposed at the cone portion away from the touch pad, then the stylus structure is simplified, but the signal receiving performance deteriorates due to large distance and noise interference

Engineering Contradiction:

Improvestylus structureVSAvoidsignal receiving performance

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The stylus is divided into distinct functional portions: the tip portion containing the receiving electrode for signal reception, the cone portion for structural support, and the emitting electrodes for signal transmission. This segmentation allows each component to be optimized for its specific function while maintaining overall structural integrity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The tip portion acts as an intermediary structure that positions the receiving electrode optimally close to the touch pad without direct contact. This intermediary element enables reliable signal reception while maintaining the structural requirements of the stylus.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of manufacture

If the receiving electrode is disposed at the cone portion, then assembly is simplified, but the electrode is easily covered or interfered by finger contact causing bad connection

Engineering Contradiction:

Improveassembly processVSAvoidconnection reliability

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The stylus is divided into distinct functional portions: the tip portion containing the receiving electrode for signal reception, the cone portion for structural support, and the emitting electrodes for signal transmission. This segmentation allows each component to be optimized for its specific function while maintaining overall structural integrity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The tip portion acts as an intermediary structure that positions the receiving electrode optimally close to the touch pad without direct contact. This intermediary element enables reliable signal reception while maintaining the structural requirements of the stylus.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Device complexity

If the receiving electrode and touch pad are separated by the first emitting electrode, then the electrode arrangement is simplified, but the first emitting electrode absorbs synchronous signals decreasing the amount received

Engineering Contradiction:

Improveelectrode arrangementVSAvoidsignal reception quality

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The stylus is divided into distinct functional portions: the tip portion containing the receiving electrode for signal reception, the cone portion for structural support, and the emitting electrodes for signal transmission. This segmentation allows each component to be optimized for its specific function while maintaining overall structural integrity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The electrode arrangement transitions from a linear one-dimensional layout to a two-dimensional spatial configuration where the receiving electrode is positioned at the tip portion while emitting electrodes are arranged at different positions along the cone portion. This dimensional change allows signals to be transmitted and received without significant absorption while maintaining structural simplicity.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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

Enhances signal reception quality by reducing noise interference and simplifies assembly by integrating electrodes, ensuring reliable and precise coordinate and tilt angle calculations.

Implementation Method 1

The touch pad 12 and the electrodes 111, 112 and 113 on the stylus 10 are capacitively coupled to each other

Methodology Applied

Scientific EffectCapacitive coupling: Capacitance

Implementation Method 2

By sensing capacitance changes for each coordinate on the touch pad 12, the touch controller 14 can obtain the position of the stylus 10 and the tilt angle

Methodology Applied

Scientific EffectCapacitance changes: Capacitance

Data Source

PatentUS11392220B2Bidirectional active stylus and sensing system

Publication Date: 2022.07.19 SILICON INTEGRATED SYSTEMS CORP

AI summary

A bidirectional active stylus and a sensing system are provided. The stylus includes a receiving electrode, a first emitting diode and a second emitting diode. The receiving electrode is configured to receive a synchronous signal from a touch pad. The receiving electrode is disposed at a position closer to the touch pad with respect to the first emitting diode and the second emitting diode. The strength of received signals is improved.