Display Driving Circuit Noise Cancellation via Coupling Signals

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Solution Overview

Problem

Large-sized interactive displays experience noise interference on sensing lines due to voltage variations in data lines, leading to incorrect user input detection, particularly at high resolutions or frame rates.

Innovation Solution

A display driving circuit with multiple data circuits and reading circuits that generate coupling signals with positive and negative pulses based on data signal edges, which are applied to sensing lines to cancel out noise, ensuring accurate sensing results.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If sensing lines are set adjacent to data lines for transmitting operation results, then the display can achieve high resolution and frame rate, but voltage variation on data lines causes noise on sensing lines leading to incorrect user input detection

Engineering Contradiction:

Improvesensing accuracyVSAvoidnoise on sensing lines

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent converts the harmful noise signal into a beneficial cancellation signal by using the same data signal that causes the noise to generate a coupling signal with opposite polarity. The reading circuit combines the sensing signal with the inverted data signal to cancel out the noise, transforming the harmful interference into a useful noise cancellation mechanism.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent introduces a coupling signal as an intermediary element between the data line and sensing line. This coupling signal, generated by the reading circuit based on the data signal, acts as a mediator that cancels the noise induced by the data line voltage variations, allowing accurate sensing despite the presence of the harmful noise.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If display resolution or frame rate is increased, then image quality improves, but noise on sensing lines increases leading to misjudgment of user operating position

Engineering Contradiction:

Improveframe rateVSAvoiduser input detection accuracy

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent implements a feedback mechanism where the reading circuit continuously monitors the data signal and generates a coupling signal that is fed back to the sensing line to cancel noise. This feedback loop ensures that as frame rate increases and noise increases, the system automatically adjusts by strengthening the noise cancellation signal to maintain detection accuracy.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS11079877B1Display driving circuit and display device having the same

Publication Date: 2021.08.03 AU OPTRONICS CORP

AI summary

A display driving circuit, suitable for a display device, includes multiple data circuits and multiple reading circuits. Each data circuit is configured to provide multiple data signals to corresponding ones of data lines of the display device. Each reading circuit is configured to compare multiple sensing signals on corresponding ones of sensing lines of the display device to generate a sensing result, and is configured generate multiple coupling signals according to the multiple data signals of a corresponding one of the multiple data circuits, respectively. The reading circuit is further configured to provide the multiple coupling signals to the corresponding ones of the multiple sensing lines. When the multiple data signals have one or more rising edges, the multiple coupling signals have one or more positive pulses. When the multiple data signals have one or more falling edges, the multiple coupling signals have one or more negative pulses.