Capacitive Touch Panel Contactless Access Control

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Solution Overview

Problem

Current data communication systems lack an efficient method for secure and reliable access control using capacitively coupled identification codes, particularly in touch-sensitive panels.

Innovation Solution

The implementation of a touch-sensitive panel system that utilizes capacitively coupled drive-sense circuits to identify devices by extracting identification codes from information signals transmitted through electric fields, enabling secure access control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional wired or wireless data communication methods are used, then data can be transmitted between devices, but secure access control using capacitively coupled identification codes cannot be implemented

Engineering Contradiction:

Improveaccess control securityVSAvoidcommunication method limitation

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent replaces traditional mechanical contact-based identification (such as physical keys or cards) with a capacitive coupling system that uses electric fields to transmit identification codes. The touch-sensitive panel detects changes in capacitance caused by the proximity of an identifying device, enabling contactless secure access control while maintaining reliability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces an intermediary capacitive coupling mechanism between the identifying device and the touch-sensitive panel. This intermediary allows data communication without direct physical contact, enabling secure access control by transmitting identification codes through electric field coupling rather than direct connection.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If capacitively coupled identification codes are used for access control, then secure identification can be achieved, but the system complexity increases

Engineering Contradiction:

Improvedevice identification accuracyVSAvoidtouch-sensitive panel system complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent makes the touch-sensitive panel multi-functional by enabling it to both detect user touch inputs and receive capacitively coupled identification codes from external devices. This universal approach allows the same hardware to serve multiple purposes: traditional touch interaction and new capacitive identification, thereby achieving reliable device identification without proportionally increasing system complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent utilizes parameter changes in the capacitive coupling system to achieve reliable identification. By detecting changes in capacitance values caused by the proximity of identifying devices, the system can accurately distinguish between different devices without requiring complex processing or additional hardware components.

Inventive Principle:

Principle #35Parameter changes

3Ease of operation

If capacitively coupled information signals are transmitted through electric fields, then contactless access control is enabled, but signal interference and noise may affect identification accuracy

Engineering Contradiction:

Improvecontactless access capabilityVSAvoididentification code detection accuracy

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The patent implements feedback mechanisms within the touch-sensitive panel to continuously monitor and adjust the capacitive coupling signals. By using feedback from the detected capacitance changes, the system can filter out noise and interference, maintaining high measurement precision while enabling contactless operation.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent employs oscillating electric fields at specific frequencies to create capacitive coupling. By using frequency-based approaches and signal oscillation, the system can distinguish meaningful identification signals from background noise and interference, improving detection accuracy while maintaining contactless operation.

Inventive Principle:

Principle #18Mechanical vibration

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 provides secure and reliable access control by accurately identifying devices through capacitively coupled information signals, enhancing data communication security and efficiency.

Implementation Method 1

changes in a self-capacitance of the row and/or column electrodes

Methodology Applied

Scientific EffectCapacitance: Capacitance

Implementation Method 2

generates electric fields by applying reference signals at one or more desired frequencies to one or more drive-sense circuits

Methodology Applied

Scientific EffectElectric Field: Electric Field

Data Source

PatentUS20250181200A1Touch sensitive panel supporting capacitively coupled access codes

Publication Date: 2025.06.05 SIGMASENSE LLC

AI summary

A method for use in a touch-sensitive panel includes generating electric fields by applying drive signals to a plurality of row electrodes and a plurality of column electrodes included in the touch-sensitive panel, and sensing at least one information signal capacitively coupled to the touch-sensitive panel by detecting impedance changes associated with the plurality of row electrodes and the plurality of column electrodes. The impedance changes are converted to received data. Based on the received data a transmission pattern associated with the at least one information signal is determined. The method further includes associating the transmission pattern with an access code.