Terminal Device Touch Input Method with Magnetic and Capacitive Detection

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Solution Overview

Problem

Existing terminal devices with both capacitive and electromagnetic induction touch panels face challenges in seamlessly switching between systems, leading to interference and inability to perform operations like drawing with a pen while holding the device, due to palm detection issues.

Innovation Solution

A terminal device with first and second touch detection units, where the first unit detects position changes based on magnetic fields and the second unit detects capacitance or resistance changes, with processing to invalidate palm contacts, allowing simultaneous detection of finger and pen operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If both capacitive and electromagnetic induction touch panels are provided in a terminal device, then the device becomes adaptable for both finger touch operations and pen touch operations, but interaction between the two systems occurs causing detection interference

Engineering Contradiction:

Improveadaptability for finger and pen touch operationsVSAvoiddetection accuracy

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The touch panel system is segmented into two independent detection layers: a capacitive touch panel for finger detection and an electromagnetic induction touch panel for pen detection. Each layer operates independently with its own detection circuitry, allowing simultaneous operation without mutual interference. The control unit selectively activates the appropriate detection system based on the input device being used.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A control unit acts as an intermediary between the two touch detection systems. It receives signals from both capacitive and electromagnetic induction detection circuits, determines which type of input device is being used, and selectively processes the appropriate signal while ignoring the other, thereby preventing detection interference.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of operation

If the capacitive system stops detection when the electromagnetic induction system detects a pen, then pen operations are enabled, but finger operations cannot be performed simultaneously with pen holding

Engineering Contradiction:

Improvepen operation capabilityVSAvoidsimultaneous finger and pen operation

Core Design Contradiction:

Ease of operationVSAdaptability or versatility

Solution Approach 1:

The detection system dynamically switches between capacitive and electromagnetic induction modes based on real-time detection. When a pen is detected by the electromagnetic induction system, only then does the system prioritize electromagnetic induction signals while maintaining capacitive detection capability for potential finger interactions. This dynamic adaptation enables both pen drawing and finger icon tapping to occur simultaneously without mutual exclusion.

Inventive Principle:

Principle #15Dynamics

3Measurement precision

If the capacitive touch panel detects palm contact, then palm touch is registered as a valid input, but it interferes with pen operations when the palm is holding the pen

Engineering Contradiction:

Improvetouch detection accuracyVSAvoidpen operation with hand holding

Core Design Contradiction:

Measurement precisionVSEase of operation

Solution Approach 1:

The control unit continuously monitors signals from both touch detection systems and uses feedback to determine the actual user intent. When electromagnetic induction detects a pen while capacitive detection registers a palm, the control unit analyzes the signal characteristics, determines that the pen is the intended input device, and filters out the palm contact as false input, allowing seamless pen operations even when the hand is holding the device.

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

Enables improved operability by accurately distinguishing between finger and pen inputs, preventing palm detection interference and allowing seamless touch operations with both fingers and pens.

Implementation Method 1

the first touch detection unit detects the coordinate position of a position indicator that comes into contact with or approaches the display panel based on a change in a magnetic field

Methodology Applied

Scientific EffectMagnetic field: Magnetic Field

Implementation Method 2

the second touch detection unit detects the coordinate position of an object that comes into contact with or approaches the display panel based on a change in capacitance or resistance

Methodology Applied

Scientific EffectCapacitance: Capacitance

Data Source

PatentUS11042244B2Terminal device and touch input method

Publication Date: 2021.06.22 SONY GROUP CORP

AI summary

An information processing including a display; a first sensor configured to detect a first object that comes into contact with or approaches the display based on a change in a magnetic field; and a second sensor configured to detect a second object that comes into contact with or approaches the display based on a change in capacitance or resistance.