Electromagnetic Induction Touch Sensing Loop Segmentation

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Solution Overview

Problem

Conventional Electromagnetic Induction (EI) touch screen technologies face challenges with high power consumption and slow input sensing due to the need for current to flow through all loop coils on a Printed Circuit Board (PCB), which reduces battery life in portable devices and prolongs sensing time.

Innovation Solution

The implementation of a dual sub-loop unit system with a controller that alternates between current reception and electromagnetic change sensing, allowing current to flow through only specific loops or groups of loops, reducing power consumption and increasing sensing speed by determining coordinates based on maximum signal loops.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If current flows through all loop coils on PCB for electromagnetic induction sensing, then sensing accuracy is maintained, but power consumption increases

Engineering Contradiction:
Improvesensing accuracyVSAvoidpower consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent divides the loop coils on the PCB into multiple groups and activates only specific groups for sensing at any given time, rather than all coils simultaneously. This segmentation allows the system to maintain sensing accuracy through the active groups while significantly reducing overall power consumption by keeping other groups inactive.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs partial action by activating only a subset of loop coils necessary for current sensing operations. Instead of using all available coils, the system selectively engages specific groups based on sensing requirements, thereby achieving adequate sensing performance with reduced energy expenditure.

Inventive Principle:
Principle #16Partial or excessive action

2Area of stationary object

If current flows through all loop coils on PCB for electromagnetic induction sensing, then electromagnetic field coverage is maximized, but battery life is reduced

Engineering Contradiction:
Improveelectromagnetic field coverageVSAvoidbattery life
Core Design Contradiction:
Area of stationary objectVSDuration of action of moving object

Solution Approach 1:

By segmenting the loop coils into multiple groups that can be selectively activated, the system maintains adequate electromagnetic field coverage through the active groups while extending battery life through reduced overall power consumption during sensing operations.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements periodic switching between different groups of loop coils, where groups are activated in sequences. This periodic action ensures that electromagnetic field coverage is maintained over time through alternating groups while allowing individual groups to remain inactive and conserve energy, thereby extending battery life.

Inventive Principle:
Principle #19Periodic action

3Measurement precision

If each loop coil is controlled to sense electromagnetic field changes sequentially, then sensing completeness is achieved, but sensing time is prolonged

Engineering Contradiction:
Improvesensing completenessVSAvoidsensing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent merges the sensing function across multiple loop coil groups, allowing multiple groups to perform sensing operations simultaneously rather than sequentially. This combining of parallel sensing operations maintains comprehensive sensing coverage while significantly reducing the total time required to complete sensing operations.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The system uses periodic switching to activate different groups of loop coils for sensing operations. By organizing sensing in periodic cycles across multiple groups, the system achieves complete sensing coverage through the cumulative effect of periodic measurements while reducing overall sensing time compared to sequential operation of all coils.

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 approach significantly reduces power consumption and shortens sensing time, enhancing user convenience by maintaining sufficient electromagnetic field strength while minimizing power usage and increasing the Signal to Noise Ratio (SNR) of sensing signals.

Implementation Method 1

The EI scheme controls generation of an electromagnetic field by applying a voltage to a loop coil disposed on a Printed Circuit Board (PCB)

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

The EI pen includes a condenser and a loop and emits the received electromagnetic field at a specific frequency

Methodology Applied
Scientific EffectElectromagnetic resonance: Resonance

Data Source

PatentEP2570777B1Sensing apparatus for measuring position of touch object by electromagnetic induction and method for controlling the same
Publication Date: 2020.11.04 SAMSUNG ELECTRONICS CO LTD
  • EP2570777B1 patent drawingFigure 1
  • EP2570777B1 patent drawingFigure 2A
  • EP2570777B1 patent drawingFigure 2B

AI summary

An electromagnetic sensing apparatus for measuring the position of a touch object by electromagnetic induction and a method for controlling the same are provided. The apparatus includes a loop unit including first and second sub-loop units for alternately receiving current and sensing an electromagnetic change; and a controller for controlling the first sub-loop unit to alternate between receiving the current and sensing the electromagnetic change in every one of a predetermined time period and controlling the second sub-loop unit to alternate between receiving the current and sensing the electromagnetic change in every predetermined time period, alternately with the first sub-loop unit