Touch Sensor Code Matrix Switching for Noise-Resistant Position Detection

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Solution Overview

Problem

Existing touch sensors face challenges in accurately detecting touch positions due to noise interference, which affects the accuracy of capacitance calculations between driving and sensing electrodes.

Innovation Solution

A touch sensor system that includes a capacitance calculating unit capable of selecting and switching between multiple code matrices based on detected noise frequencies, using a noise detecting unit to optimize capacitance calculations and improve touch position detection accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a single code matrix is used for capacitance calculation, then the device complexity is low, but the measurement precision deteriorates due to noise interference

Engineering Contradiction:

Improvetouch position detection accuracyVSAvoidcode matrix management complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent implements dynamic selection of code matrices based on detected noise frequencies. The system transitions from a static single code matrix approach to a dynamic multi-code matrix approach, where the appropriate code matrix is chosen according to the current noise environment, thereby maintaining high measurement precision without excessive complexity

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of code matrix selection based on noise frequency detection. By monitoring noise characteristics and selecting code matrices that correspond to detected noise frequencies, the system adapts to varying noise conditions and maintains accurate touch position detection

Inventive Principle:

Principle #35Parameter changes

2Measurement precision

If multiple code matrices are stored in memory for different noise conditions, then the measurement precision improves, but the loss of information increases due to noise in sensing electrodes

Engineering Contradiction:

Improvecapacitance calculation accuracyVSAvoidsignal-to-noise ratio

Core Design Contradiction:

Measurement precisionVSLoss of information

Solution Approach 1:

The patent converts the harmful effect of noise into a beneficial selection criterion. By detecting noise frequency and selecting code matrices that correspond to the detected noise characteristics, the system transforms noise from a detrimental factor into a guide for choosing the appropriate calculation matrix, thereby improving capacitance calculation accuracy

Inventive Principle:

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

Solution Approach 2:

The patent implements a feedback mechanism where noise detection results from the sensing electrodes are used to select the appropriate code matrix for capacitance calculation. This closed-loop approach ensures that the system continuously adapts to noise conditions, improving measurement precision while managing information loss

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS9519388B2Touch sensor having multiple code matrices and driving method thereof

Publication Date: 2016.12.13 SAMSUNG DISPLAY CO LTD

AI summary

A touch sensor includes a controller to detect a touch on a screen. The controller includes a voltage analyzer and a calculator. The voltage analyzer measures an output voltage of a sensing electrode of a touch sensor. The calculator calculates a capacitance between the sensing electrode and a driving electrode. The calculator calculates the capacitance based on a voltage matrix and the output voltage for one or more time periods. The voltage matrix is based on a code matrix of a plurality of code matrices.