Capacitive Sensing Mat for Contactless Object Identification

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing touch-sensitive surfaces can only detect objects that are physically in contact with the surface or in close proximity, lacking the ability to identify objects without physical contact or those that are not equipped with visual markers.

Innovation Solution

A sensing surface device comprising a sensing module coupled to a sensing mat, capable of detecting object positions, events, and movements, and generating inputs based on detected correlations between these, which can identify objects with wireless tags and detect gestures or touch events, even when objects are not in direct contact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If optical multi-touch tables with camera/projector systems are used to identify objects with visual markers, then object identification capability is improved, but device complexity and cost increase

Engineering Contradiction:
Improveobject identification capabilityVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex optical systems (cameras, projectors) with a simpler capacitive sensing system that uses electrical fields to detect and identify objects. The sensing surface uses electrode arrays to detect objects equipped with simple conductive or capacitive elements, eliminating the need for visual marker recognition systems while maintaining object identification capability.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces an intermediary sensing mechanism (capacitive coupling through the sensing surface) that allows detection of objects without direct physical contact. Objects equipped with simple conductive elements can be identified through their capacitive interaction with the electrode array, serving as a mediator between the object and the detection system.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If technologies requiring physical contact are used, then detection reliability is improved, but ease of operation and versatility deteriorate

Engineering Contradiction:
Improvedetection reliabilityVSAvoiduser interaction flexibility
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent enables continuous detection capability by allowing objects to be detected both when in contact with and when in proximity to the sensing surface. The capacitive sensing system maintains detection reliability across different interaction states (contact and non-contact), providing uninterrupted object identification and gesture recognition.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The patent creates a dynamic sensing system that adapts to different interaction modes. The system can detect objects in various states (direct contact, proximate, hovering, gesturing) and responds appropriately, providing versatility while maintaining reliability through the consistent capacitive coupling mechanism.

Inventive Principle:
Principle #15Dynamics

3Ease of operation

If capacitive multi-touch surfaces are used, then ease of operation is improved, but object identification capability deteriorates

Engineering Contradiction:
Improvetouch detection capabilityVSAvoidobject identification capability
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent applies local quality by equipping specific objects with distinctive capacitive or conductive elements that create unique electrical signatures. These localized modifications allow the sensing surface to differentiate between objects based on their individual capacitive characteristics, enabling identification while maintaining the simplicity of capacitive touch detection.

Inventive Principle:
Principle #3Local quality

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

Enables the detection and identification of objects and user interactions without physical contact, allowing for more versatile and intuitive user input and interaction with software or computing devices.

Implementation Method 1

Capacitive multi-touch surfaces can detect the positions of one or more fingers on the surface

Methodology Applied
Scientific EffectCapacitive sensing: Capacitance

Data Source

PatentEP3371680B1User input comprising an event and detected motion
Publication Date: 2021.12.01 MICROSOFT TECHNOLOGY LICENSING LLC
  • EP3371680B1 patent drawingFigure 1
  • EP3371680B1 patent drawingFigure 2
  • EP3371680B1 patent drawingFigure 3

AI summary

A sensing surface device comprises a sensing module coupled to a sensing mat. The sensing module is configured to detect a first object at a first position on the sensing mat, detect an event associated with the first object and detect a movement at a second position on the sensing mat. The sensing module is further configured to generate an input to trigger an action in software based on both the detected event and the detected movement.