3D Fine Movement Device Position Detection via Intermediary Mirror

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Solution Overview

Problem

Scanning probe microscopes face challenges in accurately measuring the three-dimensional position of samples due to hysteresis and creep in piezoelectric elements, leading to errors in displacement measurement and requiring time-consuming adjustments for different measurement conditions.

Innovation Solution

A three-dimensional fine movement device that directly detects the position of a fixation member using movement amount detecting means fixed to a coarse movement unit or base member, which allows for accurate measurement of the moving body's position by combining displacement data from multiple axes with reduced error and drift correction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Difficulty of detecting and measuring

If position detecting sensors are provided on piezoelectric elements to detect displacement, then position detection capability is improved, but measurement accuracy deteriorates due to cross-axis displacement errors

Engineering Contradiction:

Improveposition detection capabilityVSAvoidmeasurement accuracy

Core Design Contradiction:

Difficulty of detecting and measuringVSMeasurement precision

Solution Approach 1:

The patent introduces a reflection mirror as an intermediary element that reflects a laser beam to detect the position of the piezoelectric element. This indirect detection method avoids the cross-axis displacement errors that occur when sensors are directly mounted on the piezoelectric element, thereby maintaining measurement accuracy while enabling position detection.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces direct mechanical contact sensors with an optical detection system using a laser beam and reflection mirror. This substitution eliminates mechanical interference and cross-axis displacement errors, improving measurement accuracy while maintaining position detection capability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Ease of operation

If piezoelectric elements are used for fine movement control, then positioning capability is improved, but measurement accuracy deteriorates due to hysteresis and creep effects

Engineering Contradiction:

Improvepositioning capabilityVSAvoidpositioning accuracy

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The patent implements a feedback system where the actual position of the piezoelectric element is continuously detected using the laser beam and reflection mirror, and this detected position information is fed back to correct the positioning. This feedback mechanism compensates for hysteresis and creep effects, maintaining positioning capability while improving positioning accuracy.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent replaces direct reliance on piezoelectric element voltage-displacement relationship with an optical detection system. This substitution eliminates measurement errors caused by hysteresis and creep, improving positioning accuracy while maintaining the ease of operation provided by piezoelectric elements.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Ease of operation

If multiple position detecting sensors are combined to detect three-dimensional position, then positioning capability is improved, but measurement accuracy deteriorates due to error accumulation from cross-axis displacement

Engineering Contradiction:

Improvethree-dimensional positioning capabilityVSAvoidpositioning accuracy

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The patent uses a reflection mirror as an intermediary for each axis detection, where the mirror's position and orientation are controlled by individual piezoelectric elements. This intermediary approach allows independent detection of each axis without cross-axis interference, enabling accurate three-dimensional positioning without error accumulation.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent divides the three-dimensional detection system into three independent one-dimensional detection systems, each with its own laser beam and reflection mirror. This segmentation isolates the detection paths, preventing error accumulation from cross-axis displacement and maintaining high measurement precision in three-dimensional positioning.

Inventive Principle:

Principle #1Segmentation

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 simple and accurate measurement of the three-dimensional position of the moving body, improving positioning accuracy and reducing measurement errors by using non-contact sensors like diffraction gratings and electrostatic capacitance for precise displacement detection.

Implementation Method 1

using movement amount detecting means fixed to a coarse movement unit or a base member... by using non-contact sensors like diffraction gratings

Methodology Applied

Scientific EffectDiffraction: Diffraction

Implementation Method 2

using non-contact sensors like diffraction gratings and electrostatic capacitance for precise displacement detection

Methodology Applied

Scientific EffectElectrostatic capacitance: Capacitance

Implementation Method 3

one (one-axis) fine movement mechanism (piezoelectric element) that scans the sample in a z (height) direction

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentUS10161958B2Three-dimensional fine movement device

Publication Date: 2018.12.25 HITACHI HIGH TECH ANALYSIS CORP

AI summary

A three-dimensional fine movement device includes a moving body, a fixation member to which the moving body is fixed, a three-dimensional fine movement unit, to which the fixation member is fixed, and which allows for three-dimensional fine movement of the moving body with the fixation member interposed therebetween, a base member to which the three-dimensional fine movement unit is fixed, and movement amount detecting means that is fixed to the base member to detect a movement amount of the fixation member.