Measurement Probe With Segmented Movable Portions

Solution Overview

Problem

Existing shape measuring devices face challenges in achieving low measurement force and high-speed response, particularly when measuring inclined surfaces, due to the weight of the Z-axis stage and air fluctuations affecting the measurement probe's accuracy and stability.

Innovation Solution

A measurement probe configuration with a lightweight second movable portion and a heavier third movable portion, connected by springs, allows for low measurement force and high-speed movement in the Z direction while maintaining constant relative positions, reducing the influence of air fluctuations through parallel light sources and precise position measurement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional Z-axis stage is used for measurement probe movement, then measurement stability is maintained, but measurement force increases and response speed decreases

Engineering Contradiction:

Improvemeasurement stabilityVSAvoidmeasurement force

Core Design Contradiction:

ReliabilityVSForce

Solution Approach 1:

The measurement probe is divided into three separate movable portions (first, second, and third movable portions), each capable of independent Z-direction movement. This segmentation allows the system to achieve low measurement force through the lightweight second movable portion while maintaining stability through the coordinated movement of all three portions, resolving the contradiction between measurement stability and measurement force.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system dynamically coordinates the movement of three movable portions with different weights. The lightweight second movable portion provides fast response and low measurement force, while the heavier third movable portion contributes to measurement stability. The dynamic coordination of these portions allows the system to adaptively balance between force and stability requirements.

Inventive Principle:

Principle #15Dynamics

2Reliability

If a conventional Z-axis stage is used for measurement probe movement, then measurement stability is maintained, but response speed decreases

Engineering Contradiction:

Improvemeasurement stabilityVSAvoidresponse speed

Core Design Contradiction:

ReliabilityVSSpeed

Solution Approach 1:

The measurement probe is divided into three separate movable portions (first, second, and third movable portions), each capable of independent Z-direction movement. This segmentation allows the system to achieve low measurement force through the lightweight second movable portion while maintaining stability through the coordinated movement of all three portions, resolving the contradiction between measurement stability and measurement force.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system dynamically coordinates the movement of three movable portions with different weights. The lightweight second movable portion provides fast response and low measurement force, while the heavier third movable portion contributes to measurement stability. The dynamic coordination of these portions allows the system to adaptively balance between force and stability requirements.

Inventive Principle:

Principle #15Dynamics

3Adaptability or versatility

If measurement is performed on inclined surfaces, then measurement capability is improved, but measurement accuracy decreases due to air fluctuations

Engineering Contradiction:

Improvemeasurement capability on inclined surfacesVSAvoidmeasurement accuracy

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent applies different weight characteristics to different movable portions based on their specific functions. The second movable portion is designed to be lightweight for fast response and low measurement force, while the third movable portion is heavier to provide measurement stability. This local differentiation of properties allows the system to maintain high measurement accuracy even when measuring inclined surfaces, as each portion optimizes for its specific role.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS11473904B2Measurement probe

Publication Date: 2022.10.18 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD

AI summary

A measurement probe of the present disclosure that scans a surface of a measurement object to measure a three-dimensional shape or the like of the surface of the measurement object includes a first movable portion having a stylus, a second movable portion that is connected to the first movable portion to be movable in a Z direction, a third movable portion that is connected to the second movable portion to be movable in the Z direction, a first position measurer that measures a first position of the first movable portion in the Z direction, a second position measurer that measures a second position of the second movable portion in the Z direction, and a third position measurer that measures a third position of the third movable portion in the Z direction. A first relative position is calculated based on the first position and the second position. A second relative position is calculated based on the first position and the third position. The first relative position of the second movable portion with respect to the first movable portion in the Z direction and the second relative position of the third movable portion with respect to the first movable portion in the Z direction are maintained constant.