Multi-Range Non-Contact Probe with Rotating Beam Modification Element

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Solution Overview

Problem

Existing non-contact probes in coordinate measuring machines face limitations in depth of focus, making it difficult to measure workpieces at varying distances without physical contact, and have limited compatibility with advanced machine vision technologies due to restricted wired connections.

Innovation Solution

A multi-range non-contact probe that uses a rotating beam modification element to switch between diffuse and concentrated laser illumination, enabling both structured light measurement and range-finding functions, and is designed to be compatible with existing probe head systems with limited connections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a non-contact optical probe is used to measure workpiece surfaces, then physical contact is avoided and measurement precision is improved, but the depth of focus is limited making it difficult to measure surfaces at varying distances

Engineering Contradiction:
Improvemeasurement precisionVSAvoiddepth of focus
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent employs a rotating beam modification element that dynamically switches between different optical configurations. The element rotates to present different portions (diffuser vs. deflector) to the laser beam, enabling the probe to adapt between structured light mode (for precise surface measurement) and triangulation mode (for extended range finding), thus resolving the contradiction between measurement precision and depth of focus adaptability

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the optical parameters of the laser beam by using a beam modification element with different optical characteristics. By rotating the element, the system changes between diffuse illumination (broad depth of field) and concentrated illumination (extended measurement range), allowing the probe to maintain measurement capability across varying distances while preserving precision

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If Renishaw type probe head systems are used, then compatibility with existing coordinate measuring machines is improved, but the number of wired connections is limited creating a bottleneck for integrating advanced machine vision technologies

Engineering Contradiction:
ImprovecompatibilityVSAvoidconnection limitations
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The probe head is designed with multi-functionality to serve both traditional coordinate measuring machine applications and advanced machine vision technologies. By integrating a rotating beam modification element that enables multiple measurement modes (structured light and triangulation) within a single probe, the system achieves universal compatibility without requiring additional wired connections, thus resolving the contradiction between adaptability and device complexity

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

3Measurement precision

If a single optical path is used for structured light measurement, then measurement accuracy is improved, but the ability to perform range-finding functions is lost

Engineering Contradiction:
Improvemeasurement accuracyVSAvoidmeasurement function range
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent uses a dynamically rotating beam modification element that switches the laser beam between different optical paths. During structured light measurement, the diffuser portion creates diffuse illumination for accurate surface profiling. During range-finding operations, the deflector portion directs the beam along an alternate path for triangulation distance measurement. This dynamic switching resolves the contradiction by enabling both measurement functions within a single optical system

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The beam modification element rotates periodically to alternate between structured light illumination and triangulation beam paths. This periodic action allows the system to perform different measurement functions at different time intervals, maintaining high accuracy for each function while providing versatility across multiple measurement types

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

The probe achieves precise measurements over a wider range than traditional non-contact probes and allows integration of advanced features by enabling automatic interchangeability and enhanced data transmission, preventing collisions and improving measurement accuracy.

Implementation Method 1

the laser beam is directed through a diffuser portion of a rotating beam modification element so as to produce relatively diffuse illumination along a first beam path

Methodology Applied
Scientific EffectDiffusion: Diffusion

Implementation Method 2

the rotating beam modification element rotates to bring a deflector portion into the laser beam path, which causes the deflected laser beam to continue on as relatively concentrated illumination along a second beam path

Methodology Applied
Scientific EffectLight deflection: Reflection

Implementation Method 3

a triangulation reference for determining an approximate distance to a workpiece surface

Methodology Applied
Scientific EffectTriangulation: Parallax

Data Source

PatentEP1887315B1Multi-range non-contact probe
Publication Date: 2011.05.04 MITUTOYO CORP
  • EP1887315B1 patent drawingFigure 1
  • EP1887315B1 patent drawingFigure 2
  • EP1887315B1 patent drawingFigure 3

AI summary

A multi-range non-contact probe is provided which performs approximate range-finding measurement functions in addition to more precise structured light measurement functions. The probe is compatible with a probe control interface (290) which allows advanced measuring capabilities and functions to be used with a probe head system that provides a limited number of wired connections. A laser beam of the probe is directed along a first optical path during a first period for providing structured light measurement functions and is directed along a second optical path for a second time period range finding functions. A single beam modification element having at least first and second portions with different types of optical characteristics is moved to output the laser beam from the first portion along the first optical path and then to output the laser beam from the second portion along the second optical path.