Capacitive Sensor Artifact Management via Signal Inversion

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Solution Overview

Problem

Capacitive sensing devices face challenges in accurately detecting input objects in low ground mass environments, where artifacts appear as negative response values, leading to reduced detection capabilities compared to normal ground mass conditions.

Innovation Solution

The implementation of a processing system that applies a negative multiplier to negative response values from capacitive sensing devices, converting them into adjusted response values within the valid range, allowing for the detection of positional information and differentiation between input objects and artifacts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If capacitive sensing devices operate in low ground mass environments, then device portability and flexibility are improved, but detection accuracy deteriorates due to artifact interference

Engineering Contradiction:

Improveenvironmental adaptabilityVSAvoiddetection accuracy

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent converts the harmful negative response values (artifacts) into beneficial information by applying a negative multiplier to flip their sign. This transforms the harmful artifact signals into positive values that can be distinguished from actual input objects, allowing the system to maintain detection accuracy in low ground mass environments where these artifacts previously caused false detections

Inventive Principle:

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

Solution Approach 2:

The patent changes the parameter of response value sign by applying a negative multiplier to negative response values. This parameter transformation converts negative artifacts into positive values, enabling the system to differentiate between artifacts and actual input objects based on their positive response values, thereby maintaining measurement precision across different ground mass conditions

Inventive Principle:

Principle #35Parameter changes

2Device complexity

If negative response values are used directly for detection, then processing complexity is reduced, but false detection increases due to artifact misidentification

Engineering Contradiction:

Improveprocessing complexityVSAvoiddetection reliability

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent converts the harmful negative response values into beneficial positive values by applying a negative multiplier. This transformation allows the system to use the same simple threshold-based detection logic while eliminating false detections, as artifacts now produce positive values that can be reliably distinguished from actual input objects

Inventive Principle:

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

Solution Approach 2:

The patent inverts the sign of negative response values by applying a negative multiplier, flipping artifacts from negative to positive. This inversion allows the detection system to use uniform positive thresholds for both artifacts and input objects, simplifying the detection logic while improving reliability through better differentiation

Inventive Principle:

Principle #13The other way round (Inversion)

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

Enhances the ability to detect and report input objects in low ground mass conditions, maintaining or improving detection accuracy compared to normal ground mass modes, while minimizing the impact of artifacts on sensing performance.

Implementation Method 1

a capacitive sensing device. The processing system includes a sensor module and a determination module. The sensor module is coupled to transmitter electrodes and receiver electrodes. The sensor module is configured to transmit transmitter signals with the transmitter electrodes and receive resulting signals with the receiver electrodes.

Methodology Applied

Scientific EffectCapacitive coupling: Capacitance

Implementation Method 2

The sensor module is configured to transmit transmitter signals with the transmitter electrodes and receive resulting signals with the receiver electrodes. The resulting signals include effects corresponding to the transmitter signals.

Methodology Applied

Scientific EffectCapacitive sensing: Capacitance

Data Source

PatentUS10203806B2Low ground mass artifact management

Publication Date: 2019.02.12 SYNAPTICS INC

AI summary

A processing system for a capacitive sensing device includes a sensor module and a determination module. The sensor module is coupled to transmitter electrodes and receiver electrodes. The sensor module is configured to transmit transmitter signals with the transmitter electrodes and receive resulting signals with the receiver electrodes. The resulting signals include effects corresponding to the transmitter signals. The determination module is configured to determine response values from the resulting signals, and determine a first adjusted response value by applying a negative multiplier to a first response value of the response values. The first response value is a negative value. The determination module is further configured to determine positional information for a first input object based on at least one of the first adjusted response value and a second response value of the response values, and report the positional information. The second response value is a positive response value.