Touch Controller Sensing Sensitivity via Parasitic Capacitance Extraction

Solution Overview

Problem

Touch screen systems face reduced sensing sensitivity due to parasitic capacitance components and noise interference, which affect the accuracy of detecting touch events and locations on capacitive touch screen panels.

Innovation Solution

A touch controller is designed to minimize the impact of parasitic capacitance and noise by incorporating a touch data generator that processes capacitance changes via sensing lines, a signal processor that controls timing based on timing information from a timing controller, and amplification and integration circuits to enhance sensing signal accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If sensing units are used to detect touch events on capacitive touch screen panels, then touch detection capability is provided, but parasitic capacitance components reduce sensing sensitivity

Engineering Contradiction:

Improvesensing sensitivityVSAvoidparasitic capacitance

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent extracts and separates the parasitic capacitance component from the total capacitance measurement by using additional sensing lines that specifically measure the parasitic capacitance. This allows the system to isolate and remove the harmful parasitic component from the touch detection signal, thereby improving sensing sensitivity without losing the ability to detect actual touch events.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces additional sensing lines as intermediary elements that act as mediators between the touch screen panel and the controller. These intermediary sensing lines specifically measure the parasitic capacitance, enabling the controller to distinguish between parasitic capacitance effects and actual touch events, thus improving measurement precision.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Measurement precision

If touch sensing is performed using sensing lines connected to sensing units, then touch location detection is enabled, but noise interference reduces detection accuracy

Engineering Contradiction:

Improvedetection accuracyVSAvoidnoise

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent implements a feedback mechanism where the controller receives capacitance measurements from multiple sensing lines, including dedicated parasitic capacitance sensing lines. The controller uses this feedback information to calculate and subtract parasitic capacitance effects from the touch detection signals, continuously improving detection accuracy by compensating for noise and interference in real-time.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent introduces additional sensing lines as intermediary elements that act as mediators between the touch screen panel and the controller. These intermediary sensing lines specifically measure the parasitic capacitance, enabling the controller to distinguish between parasitic capacitance effects and actual touch events, thus improving measurement precision.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Area of stationary object

If multiple sensing units are arranged in rows and columns, then comprehensive touch coverage is achieved, but horizontal parasitic capacitance between sensing units increases

Engineering Contradiction:

Improvetouch coverage areaVSAvoidhorizontal parasitic capacitance

Core Design Contradiction:

Area of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The patent segments the capacitance measurement function into multiple independent sensing lines, with dedicated lines for measuring parasitic capacitance between adjacent sensing units. This segmentation allows the system to independently measure and compensate for horizontal parasitic capacitance effects while maintaining comprehensive touch coverage across the entire screen area.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces additional sensing lines as intermediary elements that act as mediators between the touch screen panel and the controller. These intermediary sensing lines specifically measure the parasitic capacitance, enabling the controller to distinguish between parasitic capacitance effects and actual touch events, thus improving measurement precision.

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

The solution improves sensing sensitivity and accuracy by reducing the influence of parasitic capacitance and noise, enabling precise detection of touch events and locations on capacitive touch screen panels.

Implementation Method 1

If a user touches a screen of the touch screen panel with his/her finger or a touch pen, a capacitance value of a corresponding sensing unit changes

Methodology Applied

Scientific EffectCapacitance: Capacitance

Data Source

PatentUS10768760B2Touch controller having increased sensing sensitivity, and display driving circuit and display device and system having the touch controller

Publication Date: 2020.09.08 SAMSUNG ELECTRONICS CO LTD

AI summary

A touch controller includes a touch data generator that is connected to a plurality of sensing lines, the touch data generator sensing a change in capacitance of a sensing unit connected to each of the sensing lines and generating touch data by processing the sensing signal corresponding to the result of sensing; and a signal processor that controls a timing of generating the touch data by receiving at least one piece of timing information for driving a display panel from a timing controller, and then providing either the timing information or a signal generated from the timing information as a control signal to the touch data generator.