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Your guide to Machine Vision
Guide Topics
Machine Vision
System parts
Machine Vision Systems
Vision Techniques
Lighting Techniques
Major Illumination Types
Illumination Intensity
Illumination Basics
Specific Lighting Techniques
Polarizing Filters
Information About Lenses
Lens Basics
Lens Selection
Lens Characteristics
Image Processing Techniques
Major Image Processing Methods
Grayscale Edge Detection
Normalized Correlation Search
Binarization Stabilization Technique
Binarization Application Examples
Labeling
COUNT
Examples of Technique Application
Coated Glossy Surface, Engraved Mark Inspection
Detection of Scratches and Chips on a Low Contrast Surface
Detection of the Dimensions and Shape of Transparent Objects
Detection of Concave and Convex, Print on Curved Surface, and Contamination
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Machine Vision Systems
  

Detection of Concave and Convex, Prints on Curved Surface, and Contamination

Dome Lighting Bathes a Workpiece in Soft Indirect Light to Create an Image without Shadow or Halation

Detection of Print on Aluminum Packages
Print on aluminum packages, which is hard to detect due to shadows created by concave and convex areas and halation caused by film, are detected through the transparent film.
Detecting print on an aluminum package  
In the case of simple reflected light
Print on an aluminum package with simple reflection
The print cannot be identified due to diffused reflection.
 
In the case of dome light
Print on aluminum with a dome light
The background image shade is eliminated and only the print appear.
Dome Lighting Technique
A dome light irradiates indirect light from various directions. In the case of workpieces with infinite form, shadows from concave and convex areas are easily apparent if irradiated by direct light from directly above and they are also prone to glare due to glossy surfaces. However, because this method can uniformly irradiate soft diffused light over such workpieces, this renders the surface even and improves the contrast between the detecting points and the background.
Set-up diagram using dome lighting

Uniform Light Irradiated on a Curved Surface Changes a Surface from Glossy to Flat
Detection of Holes and Black Scales
Holes and black scales left on a die-cast part following the processing of a curved-surface are detected.
Detecting defects on a curver surface  
In the case of simple reflected light
Detecting flaws on a curved surface with simple reflection
The position is not clearly detected.
 
In the case of dome light
Detecting flaws on a curved surface with a dome light
The surface is uniformly captured and defects can be detected.
Dome Lighting Technique
A dome light allows uniform light to be irradiated on any point of the curved surface. Unlike direct light, neither glare nor shadow occurs, allowing accurate detection.
Dome lighting set-up diagram


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