Touch Sensing Unit Peripheral Electrode Area Compensation

Solution Overview

Problem

Display devices with touch sensing units face inaccuracies in touch sensing due to differences in parasitic capacitance among sensor groups, leading to incorrect touch recognition or failure to detect user inputs.

Innovation Solution

The implementation of a touch sensing unit with a configuration of sensor groups and peripheral electrodes, where the area of each sensor group and peripheral electrode is optimized to minimize parasitic capacitance differences, using auxiliary electrodes and lines to compensate for capacitance variations, ensuring uniform capacitance across all groups.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If sensor groups have different areas to match display device shape, then the display device can have various shapes (circular, rectangular), but parasitic capacitance differences increase causing touch sensing inaccuracy

Engineering Contradiction:

Improvedisplay device shapeVSAvoidtouch sensing accuracy

Core Design Contradiction:

ShapeVSMeasurement precision

Solution Approach 1:

The patent applies local quality by making peripheral electrodes have different areas corresponding to the area differences of sensor groups. Specifically, sensor groups with larger areas are paired with peripheral electrodes of smaller areas, and vice versa. This localized adjustment compensates for parasitic capacitance differences while maintaining the overall display device shape flexibility.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the area parameter of peripheral electrodes to compensate for parasitic capacitance variations. By adjusting the area of peripheral electrodes inversely to the area of their corresponding sensor groups, the patent equalizes the total capacitance across different sensor groups, thereby improving touch sensing accuracy.

Inventive Principle:

Principle #35Parameter changes

2Area of stationary object

If sensor groups have larger area to cover more display area, then touch sensing coverage increases, but parasitic capacitance increases causing signal differences

Engineering Contradiction:

Improvesensor group areaVSAvoidtouch sensing signal consistency

Core Design Contradiction:

Area of stationary objectVSReliability

Solution Approach 1:

The patent applies local quality by making peripheral electrodes have different areas corresponding to the area differences of sensor groups. Specifically, sensor groups with larger areas are paired with peripheral electrodes of smaller areas, and vice versa. This localized adjustment compensates for parasitic capacitance differences while maintaining the overall display device shape flexibility.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the area parameter of peripheral electrodes to compensate for parasitic capacitance variations. By adjusting the area of peripheral electrodes inversely to the area of their corresponding sensor groups, the patent equalizes the total capacitance across different sensor groups, thereby improving touch sensing accuracy.

Inventive Principle:

Principle #35Parameter changes

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

This configuration enhances the accuracy of touch sensing by reducing signal differences caused by capacitance variations, leading to improved recognition of user inputs and increased reliability in touch detection.

Implementation Method 1

The parasitic capacitance of a sensor group may increase with the area of the sensor group. Accordingly, there may be a difference in a touch sensing signal depending on the area of the sensor groups.

Methodology Applied

Scientific EffectParasitic capacitance: Parasitic Capacitance

Implementation Method 2

a first peripheral electrode electrically connected to the first sensor group, and a second peripheral electrode electrically connected to the second sensor group, wherein an area of the first sensor group is smaller than an area of the second sensor group in a plan view, and wherein an area of the first peripheral electrode is greater than an area of the second peripheral electrode in the plan view

Methodology Applied

Scientific EffectCapacitance: Capacitance

Data Source

PatentUS11797140B2Touch sensing unit and display device including the same

Publication Date: 2023.10.24 SAMSUNG DISPLAY CO LTD

AI summary

Provided is a touch sensing unit comprises a first sensor group extending in a first direction and including a plurality of sensor electrodes; a second sensor group extending in the first direction and including the plurality of sensor electrodes; a first peripheral electrode electrically connected to the first sensor group; and a second peripheral electrode electrically connected to the second sensor group, wherein an area of the first sensor group is smaller than an area of the second sensor group in a plan view, and an area of the first peripheral electrode is greater than an area of the second peripheral electrode in the plan view.