Tool Shape Measurement Optics Using Reflective Backlighting

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Solution Overview

Problem

The image pickup type tool shape measurement device is affected by foreign substances like chips and coolant adhering to the diffuser panel, causing shadows in the background that interfere with accurate tool shape measurement.

Innovation Solution

A reflective surface is formed on the shutter to scatter light, with a removal member like a brush to clean foreign substances, ensuring that scattered light reaches the image pickup device, and the illumination system uses diffused reflection to create a clear image with the tool appearing darker than the background.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a diffuser panel is used to illuminate the tool from behind, then the tool background becomes bright and the tool appears dark for measurement, but foreign substances like chips and coolant may adhere to the diffuser panel causing shadows that interfere with measurement

Engineering Contradiction:
Improvetool shape measurement precisionVSAvoidshadow interference from foreign substances
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The harmful diffuser panel is extracted and removed from the system. Instead of using a diffuser panel that accumulates foreign substances, the invention uses a reflector with a reflective surface that directs light without being in the path where chips and coolant adhere, thereby eliminating the shadow interference problem while maintaining bright background illumination for accurate tool measurement

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

A reflector is introduced as an intermediary element between the light source and the tool. The reflector uses its reflective surface to redirect light onto the tool background, achieving the desired illumination effect without the diffuser panel's vulnerability to foreign substance adhesion. This intermediary solution maintains measurement precision while avoiding shadow interference

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the tool storage chamber is isolated by a partition wall from the machining chamber, then tools are protected from direct contamination, but the partition wall must have an opening for tool exchange that allows foreign substances to enter the storage chamber

Engineering Contradiction:
Improvetool measurement reliabilityVSAvoidtool exchange capability
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The problematic diffuser panel located in the tool storage chamber is extracted and removed. By eliminating this component, the system no longer requires the same level of isolation protection, as the new reflector-based illumination system is not susceptible to foreign substance adhesion. This allows the partition wall opening to remain open for tool exchange without compromising measurement reliability

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention replaces the sensitive diffuser panel with a more robust reflector system that can tolerate the presence of foreign substances. The reflector material (such as aluminum or stainless steel) is resistant to chip and coolant adhesion, making it effectively 'contamination-proof' and eliminating the need for strict chamber isolation during tool exchange operations

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 configuration reduces the impact of foreign substances on tool shape measurement, providing accurate and reliable measurements by preventing shadows and ensuring the tool appears dark in the image, thus enhancing measurement precision.

Implementation Method 1

a reflective surface which scatters light; a reflector which is disposed so that light scattered from the reflective surface proceeds at least partially toward the image pickup device

Methodology Applied
Scientific EffectLight scattering: Scattering

Data Source

PatentEP3257626B1Machine tool with tool shape measurement apparatus
Publication Date: 2021.12.08 MAKINO MILLING MASCH CO LTD
  • EP3257626B1 patent drawingFigure 1
  • EP3257626B1 patent drawingFigure 2~3
  • EP3257626B1 patent drawingFigure 4~5

AI summary

A tool shape measurement apparatus (24) for imaging a tool (5) is provided with: a camera (25) for imaging the tool (5) disposed at a previously determined imaging position; a shutter (52) disposed on the opposite side of the tool (5) from the camera (25); an illuminating device (26) for shining light toward the shutter (52); and a control device (27) for calculating the shape of the tool (5) from an image of the tool (5). The illuminating device (26) is disposed so that an image in which the tool (5) is darker than the background of the tool (5) is captured due to light reflected at the reflecting surface (52a) of the shutter (52).