Touch Screen Input Device Master-Slave Communication

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Solution Overview

Problem

Existing touch screen systems require input devices like styli to continuously listen for signals from the touch screen, leading to power consumption issues and potential interference with touch input detection, as they need to synchronize with the touch screen's scanning window to avoid collisions.

Innovation Solution

The system allows the input device to act as the 'master' and the touch screen as the 'slave', enabling the input device to transmit data without needing to determine a communication window, thereby reducing power consumption and avoiding synchronization requirements, and includes methods for detecting the input device using spectral analysis or search scans.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If input devices continuously listen for signals from the touch screen to synchronize communication, then data transmission can occur, but power consumption increases and interference with touch input detection may occur

Engineering Contradiction:

Improvedata transmission efficiencyVSAvoidpower consumption

Core Design Contradiction:

ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent inverts the traditional master-slave relationship by making the input device the master that initiates communication and the touch screen the slave that responds. This allows the input device to transmit data without continuously listening for touch screen signals, reducing power consumption while maintaining communication effectiveness

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The touch screen performs periodic scanning at fixed intervals to detect input devices and receive data transmissions. This periodic scanning approach allows the system to maintain data transmission capability while reducing the need for continuous active listening, thereby lowering power consumption

Inventive Principle:

Principle #19Periodic action

2Reliability

If input devices continuously listen for synchronization signals, then data can be transmitted in correct time windows, but this may interfere with touch input detection

Engineering Contradiction:

Improvedata transmission synchronizationVSAvoidinterference with touch input detection

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent segments the touch screen operation into distinct phases: touch input scanning phases and input device communication phases. During touch scanning, the touch screen detects finger touches; during communication phases, it listens for data from input devices. This segmentation prevents interference between touch detection and data transmission

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces timing control and phase management as intermediaries to coordinate between touch input detection and data transmission. The system uses intermediate buffer storage and timed transmission windows to ensure that data from input devices is received during appropriate phases without interfering with ongoing touch detection operations

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS9582105B2Input device for touch sensitive devices

Publication Date: 2017.02.28 APPLE INC

AI summary

A method for receiving data from an input device to a computing device through a touch interface. The method includes detecting an input device, synchronizing with the input device by receiving a position signal and activating an input device scan of the touch interface, receiving a data signal from the input device through at least one of a sense line or a drive line of the touch interface, and scanning the touch interface for a touch input by applying a stimulation signal to the at least one drive line and analyzing the at least one sense line.