Magnetic Encoder Merging Phase and High Resolution Signals

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Solution Overview

Problem

Existing magnetic encoders require multiple components, including optical encoders, to achieve high resolution signals, leading to increased size and production costs.

Innovation Solution

A magnetic encoder design utilizing a single magnetic field generating member with alternately magnetized poles and multiple spaced-apart magnetic sensors, each with channels having magnetic detection elements that produce phase signals and high resolution signals through logical processing and output to open collectors or drains.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If an optical encoder is added to a magnetic encoder to obtain high resolution signals, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improvesignal resolutionVSAvoidnumber of parts
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines the functions of phase signal generation and high resolution signal generation into a single magnetic encoder system. Multiple magnetic sensors detect the same magnetic field from one magnetic field generating member, and their outputs are processed through logic circuits to generate both phase signals and high resolution signals, eliminating the need for separate optical encoders

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The magnetic field generating member and magnetic sensors serve multiple functions simultaneously: they generate phase signals for basic motor control and high resolution signals for fine position control. The single magnetic encoder system performs what previously required both magnetic and optical encoders

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Measurement precision

If an optical encoder is added to a magnetic encoder to obtain high resolution signals, then measurement precision is improved, but the size of the apparatus increases

Engineering Contradiction:
Improvesignal resolutionVSAvoidapparatus size
Core Design Contradiction:
Measurement precisionVSArea of stationary object

Solution Approach 1:

The patent merges the optical encoder and magnetic encoder into a single magnetic encoder system, reducing the overall apparatus size by eliminating redundant components while maintaining both phase signal and high resolution signal generation capabilities

Inventive Principle:
Principle #5Merging (Combining)

3Measurement precision

If an optical encoder is added to a magnetic encoder to obtain high resolution signals, then measurement precision is improved, but production cost increases

Engineering Contradiction:
Improvesignal resolutionVSAvoidproduction cost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent combines multiple encoder functions into a single magnetic encoder system, reducing the number of parts that need to be manufactured, assembled, and tested, thereby lowering production costs while maintaining high resolution signal generation

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The magnetic encoder system performs multiple functions (phase signal generation and high resolution signal generation) that previously required separate devices, reducing overall system cost by eliminating redundant components

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 design enables the generation of both phase and high resolution signals with reduced component count, facilitating miniaturization and lower production costs while maintaining high accuracy.

Implementation Method 1

each channel including a magnetic detection element having an electrical characteristic varying depending on an external magnetic field from the magnetic field generating member

Methodology Applied
Scientific EffectMagnetic field detection: Magnetic Field

Implementation Method 2

In a magnetic sensor for magnetoelectric conversion, magnetoreristance elements A1-A4 and B1-B4 whose electric resistance is varied in accordance with the intensity of a magnetic field

Methodology Applied
Scientific EffectMagnetoelectric conversion: Hall Effect

Data Source

PatentEP2722649B1Magnetic encoder
Publication Date: 2018.12.05 ALPS ALPINE CO LTD
  • EP2722649B1 patent drawingFigure 1
  • EP2722649B1 patent drawingFigure 2~3
  • EP2722649B1 patent drawingFigure 4A~4B

AI summary

A magnetic encoder includes a magnetic field generating member (11) having different magnetic poles magnetized alternately in a moving direction, multiple magnetic sensors (12) arranged spaced apart from one another in a direction parallel to the moving direction such that the magnetic sensors are not in contact with the magnetic field generating member, and multiple channels (20, 21) provided for each magnetic sensor, each channel including a magnetic detection element (18, 19) having an electrical characteristic varying depending on an external magnetic field from the magnetic field generating member. The single magnetic field generating member enables a phase signal to be generated from each of the magnetic sensors, the phase signals being out of phase, and enables a high resolution signal to be generated based on outputs of the channels such that the high resolution signal includes multiple pulses within a wavelength of each phase signal.