Touch Screen Driver Segmentation and Synchronization

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Solution Overview

Problem

Existing touch screen drivers require a large number of channels to handle increased resolution and size, leading to the need for new integrated circuits that can efficiently manage a growing number of Tx and Rx channels.

Innovation Solution

A touch screen driver system utilizing multiple integrated circuits that are synchronized to divide the driving and sensing operations across the touch screen, allowing for efficient operation with a relatively small number of channels by sharing Tx and Rx lines and using synchronization signals to coordinate sensing operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the number of Tx channels and Rx channels is increased to handle higher resolution and larger touch screen size, then the touch screen driver can support higher resolution and larger size, but the device complexity and integration difficulty increase significantly

Engineering Contradiction:
Improvetouch screen resolutionVSAvoidintegrated circuit channel complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The touch screen driver is segmented into multiple independent integrated circuits, each handling a subset of Tx and Rx channels. This division allows the system to support high-resolution touch screens by distributing the channel handling across multiple simpler ICs rather than requiring one complex IC to handle all channels simultaneously.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Each integrated circuit is designed with universal functionality to handle both Tx channel driving and Rx channel sensing operations. The ICs can be configured to work with different channel assignments, providing flexibility in system design while maintaining consistent operational characteristics across all channels.

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

2Device complexity

If multiple integrated circuits are used to drive a touch screen, then the device complexity is reduced, but synchronization issues may arise causing sensing errors

Engineering Contradiction:
Improveintegrated circuit channel complexityVSAvoidsensing accuracy
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

A synchronization signal is generated based on the driving signal and fed back to all integrated circuits. This feedback mechanism ensures that all ICs operate in sync with the same timing reference, preventing sensing errors that would otherwise occur due to timing mismatches between multiple independent ICs.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The synchronization signal is generated in advance based on the driving signal characteristics before the actual sensing operation begins. This preliminary synchronization ensures that all integrated circuits are properly aligned and ready to operate together without timing conflicts during the measurement phase.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If one integrated circuit generates and transmits synchronization signals to others, then synchronized operation is achieved, but the signal transmission path and timing coordination become more complex

Engineering Contradiction:
Improvesynchronization accuracyVSAvoidsignal coordination complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The synchronization signal acts as an intermediary that mediates the coordination between multiple integrated circuits. By using a dedicated synchronization signal path separate from the data and control signals, the timing coordination is simplified and isolated from other signal interactions, reducing overall system complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP2657814B1Touch screen driver
Publication Date: 2018.10.31 LG DISPLAY CO LTD
  • EP2657814B1 patent drawingFigure 1
  • EP2657814B1 patent drawingFigure 2
  • EP2657814B1 patent drawingFigure 3~4

AI summary

A touch screen driver (30) includes a plurality of integrated circuits for dividedly driving a touch screen (TSP). One of the plurality of integrated circuits, which generates a driving signal to be supplied to Tx lines of the touch screen (TSP), transmits a synchronization signal synchronized with the driving signal to other integrated circuit. The other integrated circuit receiving the synchronization signal receives charges of the touch sensors (TSN) through Rx lines of the touch screen (TSP) in response to the synchronization signal.