Touch Circuit Temperature Compensation for False Touch Detection

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Solution Overview

Problem

In low temperature environments, the temperature changes caused by a user's body on a touchscreen can lead to false touch detections, as the capacitance changes due to temperature fluctuations rather than actual touch events, causing the touch circuit to incorrectly identify touches.

Innovation Solution

Incorporating a temperature sensor and a touch circuit that refrains from outputting touch information if the temperature is within a designated range, ensuring that only significant capacitance changes outside this range are reported to the processor, thereby distinguishing between temperature-induced and actual touch events.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the touch circuit monitors capacitance changes continuously, then touch detection capability is improved, but false touch detections increase due to temperature-induced capacitance changes

Engineering Contradiction:

Improvetouch detection accuracyVSAvoidfalse touch rate

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

A temperature sensor is introduced as an intermediary component to monitor temperature changes. The temperature information serves as a mediator that helps distinguish between capacitance changes caused by actual touches versus those caused by temperature fluctuations, thereby reducing false touch detections while maintaining accurate touch detection

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The system dynamically adjusts touch detection parameters based on temperature conditions. When temperature changes exceed a threshold, the system modifies capacitance change thresholds or ignores certain capacitance variations, allowing accurate touch detection to be maintained while filtering out temperature-induced false signals

Inventive Principle:

Principle #35Parameter changes

2Speed

If the touch circuit outputs all capacitance changes, then responsiveness is improved, but erroneous touch information increases

Engineering Contradiction:

Improvetouch response speedVSAvoiderroneous touch information

Core Design Contradiction:

SpeedVSLoss of information

Solution Approach 1:

The system implements a feedback mechanism where temperature sensor data is continuously fed back to the touch circuit. This feedback loop allows the touch circuit to real-time adjust its output decisions, quickly suppressing erroneous touch information while maintaining rapid response to genuine touches through the fast feedback path

Inventive Principle:

Principle #23Feedback

3Measurement precision

If temperature compensation is applied continuously, then touch accuracy is improved, but energy consumption increases

Engineering Contradiction:

Improvetouch measurement accuracyVSAvoidenergy consumption

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

Instead of continuous temperature compensation, the system employs periodic action by only applying compensation when temperature changes exceed a predetermined threshold. The temperature sensor monitors continuously but compensation is triggered periodically only when necessary, reducing energy consumption while maintaining touch measurement accuracy during temperature-stable periods

Inventive Principle:

Principle #19Periodic action

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 solution effectively reduces false touch detections by differentiating between capacitance changes due to temperature fluctuations and actual user interactions, enhancing the accuracy of touch recognition in low temperature conditions.

Implementation Method 1

a temperature sensor configured to sense temperature information of the electronic device

Methodology Applied

Scientific EffectTemperature sensing:

Implementation Method 2

The capacitance (e.g., mutual capacitance) of the electrode on (or near) the point touched by the user may be changed by contact (or proximity) with the user's body

Methodology Applied

Scientific EffectCapacitance change detection: Capacitance

Implementation Method 3

due to thermal conduction, the temperature of the touched point may then drop and revert to the temperature of the nearby portion of the touchscreen

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentUS11662859B2Touch circuit for preventing erroneous touch due to temperature change, electronic device comprising touch circuit, and method for operating same

Publication Date: 2023.05.30 SAMSUNG ELECTRONICS CO LTD

AI summary

According to certain embodiments, an electronic device may include a temperature sensor sensing temperature information, a processor, and a touch circuit. The touch circuit may identify that the temperature information is lower than or equal to a designated threshold temperature, and may identify whether values included in pieces of touch sensing information are within a designated range. Each of the pieces of touch sensing information may include multiple values corresponding to multiple nodes of the touch circuit. On the basis of the result of identifying whether the values included in the touch sensing information are within the designated range, the touch circuit may not output touch information associated with at least one first node having a value within the designated range, to the processor. Alternatively, the touch circuit may output touch information associated with at least one second node having a value outside the designated range, to the processor.