Dynamic Electrode Selection for Uplink Signal Reliability

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Solution Overview

Problem

The existing position detection systems using electronic pens and capacitance touch sensors face issues where fluctuations in the reference potential caused by a human body can lead to temporary undetectability of uplink signals, complicating signal processing and requiring additional functions in the sensor controller.

Innovation Solution

A position detection system that includes an electronic pen with multiple electrodes and a sensor control circuit connected to a capacitance touch sensor, which dynamically selects and changes the set of transmission and reception electrodes for uplink signals over time, ensuring continuous detection by alternating between different electrode configurations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a sensor controller is configured to transmit a cancel signal along with the uplink signal to prevent the uplink signal from appearing at the ground end of the reception circuit, then the uplink signal detectability is improved, but the device complexity increases due to additional signal processing functions

Engineering Contradiction:

Improveuplink signal detectabilityVSAvoidsensor controller complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the harmful component (cancel signal) from the transmission and eliminates it by using a different approach. Instead of transmitting the uplink signal through sensor electrodes and adding a cancel signal, the invention uses a dedicated transmission electrode that directly transmits the uplink signal without requiring cancel signal processing, thereby simplifying the sensor controller while maintaining signal detectability

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent segments the electrode functions by separating the transmission electrode from the sensor electrodes. The transmission electrode is dedicated solely to transmitting the uplink signal, while sensor electrodes are used for detecting downlink signals and touch input. This functional segmentation eliminates the need for complex signal processing to prevent ground potential fluctuations

Inventive Principle:

Principle #1Segmentation

2Adaptability or versatility

If the uplink signal is transmitted through sensor electrodes to the electronic pen, then the existing electrode structure is utilized, but signal undetectability occurs due to human body contact causing reference potential fluctuations

Engineering Contradiction:

Improveelectrode utilizationVSAvoidsignal detectability

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent divides the electrode system into distinct functional groups: transmission electrodes dedicated to uplink signal transmission, and sensor electrodes for downlink signal reception and touch detection. This segmentation isolates the uplink transmission path from human body interference, ensuring reliable signal detectability while maintaining versatile electrode utilization

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces a dedicated transmission electrode as an intermediary element between the sensor controller and the electronic pen. This intermediary electrode provides a stable transmission path that is not affected by human body contact, thereby maintaining signal reliability without compromising the adaptability of the existing sensor electrode structure

Inventive Principle:

Principle #24Intermediary (Mediator)

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 effectively prevents temporary undetectability of signals at the pen electrode due to human body-induced fluctuations, simplifying signal processing and maintaining uninterrupted communication between the electronic pen and the touch sensor.

Implementation Method 1

capacitance touch sensor that detects a position

Methodology Applied

Scientific EffectCapacitance: Capacitance

Implementation Method 2

The electronic pen receives the uplink signal through capacitive coupling formed between an electrode provided at the pen tip and a sensor electrode group

Methodology Applied

Scientific EffectCapacitive coupling: Capacitance

Data Source

PatentUS20250021187A1Position detection system, sensor control circuit, and electronic pen using selected portion of sensor electrodes as transmission electrodes

Publication Date: 2025.01.16 WACOM CO LTD

AI summary

A position detection system is provided including an electronic pen including pen electrodes, and a sensor control circuit that is connected to a capacitance touch sensor including sensor electrodes. The sensor control circuit controls transmission of uplink signals through the touch sensor. The electronic pen selects one or more reception electrodes from the pen electrodes, and the sensor control circuit selects transmission electrodes from the sensor electrodes. A set of the transmission electrodes and the reception electrodes of the uplink signals is changed according to time in a time-division manner.