MARKING & DECODING 2D SYMBOLOGIES

: Microscan Marking Decoding 2D Symbologies Marking_Decoding_2D_Symbologies Webinars

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MARKING & DECODING 2D
SYMBOLOGIES

Track, Trace & Control Solutions
© 2010 Microscan Systems, Inc.

About Your Instructors

Matt Van Bogart
Global Channel Manager
Joined Microscan in 1999
Held management positions in
Marketing, Product Management
and Sales

Juan Worle
Technical Training Coordinator
With Microscan since 1996
Held positions in Service, Applications,
Sales and Marketing

© 2010 Microscan Systems, Inc.

Today’s Objectives

By the end of today’s Webinar, you will know
 Proper marking techniques for your application &
maximizing readability
 Different marking methods available
 How a 2D symbol is decoded

© 2010 Microscan Systems, Inc.

Today’s Topics

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
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Selecting a Symbology
Marking Methods
Decoding a 2D Symbol
Maximizing Readability
Decodability

© 2010 Microscan Systems, Inc.

MARKING METHODS

© 2010 Microscan Systems, Inc.

Selecting a Symbology
Select a Symbology
 Many things to consider:
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Space, surface shape & quality
Amount of data
Cost of equipment (printer type, scanner vs. imager, consumables)
Cosmetic, product appearance
Type of equipment down the supply chain

 Some applications may only require a laser scanner
– Good contrast, non-reflective material, flat surface

 Data Matrix is more common for DPM
– Easy to make with many marking methods
– Easy to decode on different substrates
– Error correction recovers from misprints
and damage
© 2010 Microscan Systems, Inc.

Some DPM marks can be
decoded with a laser scanner

Marking Methods
Print
Inkjet, laser, thermal printers onto labels and paper
 Most commonly used
 This can be done with standard office printers
 Marks are fragile and temporary
Advantage:
-Supplies are readily available
-Simple and fast to make
-High quality/contrast
Disadvantage:
-Fragile
-Consumables

© 2010 Microscan Systems, Inc.

-Warehousing
-Packaging
-Pharmaceutical

Marking Methods
Electrochemical (chem etch)
Electrical current passes through a stencil into the conductive metal part
 Material is not weakened or distorted
 Good for thin or fragile material
 Can produce toxic fumes
Advantage:
- Permanent
- High quality mark
- No debris from process
Disadvantage:
- Potentially toxic material bi-product
- Low-volume use
- Complex process

© 2010 Microscan Systems, Inc.

- Military
- Aerospace
- Medical device

Marking Methods
Direct Ink Jet
An ink is applied by spray nozzles, typically resulting in round dots
 Food grade inks
 Quality and contrast varies
 Print on difficult shapes
Advantage:
- High contrast if done right
- Low entry cost
-No damage to part surface
-High speed printing
Disadvantage:
-Temporary in most cases
-Easy to make a poor print
-Contrast varies
-Consumables (ink)
© 2010 Microscan Systems, Inc.

- Post-packaging
- Warehousing
- Automotive
- Bio-science
- Pharmaceuticals
- Packaging
- Clinical R&D
- Electronics

Marking Methods
Laser Etch: Anneal, Ablation
Laser is used to cut away a thin layer of surface material.
 Ablation exposes another material for higher contrast.
 Anneal heats a Materials surface to alter its composition.

Advantage:
-Clean, high resolution
-Can be high contrast
-Permanent (if not using labels)
-No consumables (if not using labels)
-Does not alter part surface (anneal)
Disadvantage:
-Possible consumables (if using labels)
-Affects surface integrity
-Process creates debris
© 2010 Microscan Systems, Inc.

-Aerospace
-Military
-Automotive
-Electronics
-Surgical tools
-Medical Implants

Marking Methods
Dot Peen
A multi-axis pointed stylus hits a part like a hammer, which displaces
material, leaving a dimple in its place
 Typically used on metals
 Recommended for automotive and aerospace
where the marks must last the life of the part
Advantage:
- Permanent
-No consumables
Disadvantage:
- Alters surface
- Low contrast mark
- More difficult to read
- Inconsistent depth will create smaller elements
- Background noise
© 2010 Microscan Systems, Inc.

-Automotive
- Aerospace
- Military

DECODING 2D SYMBOLS

© 2010 Microscan Systems, Inc.

Capture an Image
 A light source is used to illuminate the part
 A sensor captures the reflected light and converts to a digital image
 Software is used to decode the image

© 2010 Microscan Systems, Inc.

Decoding a 2D Symbol
Decoding consists of two parts:
Locate


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Decoder must locate the symbol within the image using unique traits to
each symbology
A higher resolution sensor will take longer to locate
It will take longer to locate a symbol in a noisy field of view

Decode

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Decoding algorithms are unique to the products you are using
When a decoder is configured to look for several symbologies, decode time
will be longer
A minimum number of Pixels Per Element (PPE) will ensure consistent
decodes

© 2010 Microscan Systems, Inc.

Decoding a 2D Symbol
Pixels Per Element (PPE)
• The number of pixels that cover an element in either the X or Y dimension.
• The number of Pixels Per Element is determined by:
• Symbol size (size of the elements)
• Camera resolution (sensor size)
• Field of view (optics)

One Element
2 Pixels per
Element

Microscan’s read range tables have this calculated for you.
© 2010 Microscan Systems, Inc.

Maximizing Readability
Consider the following when designing a code:
 Contrast: maximize the difference between white and black elements
– Easier to read
– No special lighting or algorithms

 Quiet Zone: increase the Quiet Zone to improve decode speeds
 Element size: the larger the better for DPM
– Overcome surface texture (DPM)
– More versatile with reading equipment

 Quality: good codes decode more reliable
– Damaged codes use error correction
– Improperly marked codes reduce contrast

 Mark position: choose a smooth flat location
– Avoid curved or bumpy surfaces if possible
– Position where it is accessible by a reader
© 2010 Microscan Systems, Inc.

A nicely printed Dot Peen
can be easy to read

Decodability
Common problems with Direct Part Marks
 Dot center offset
– The elements do not have a consistent placement

 Cell fill

Dot center offset

– The percentage that an element fills its ideal size
– Slight underfill is typically more readable than overfill

 Contrast
– Low contrast can be a problem on DPMs
– Adjust the imager and lighting angles to optimize

Cell fill

The best solution:
Contrast

© 2010 Microscan Systems, Inc.

Decodability
Common problems with Direct Part Marks
 Modulation
– Uneven printing or illumination can make it difficult to
read a code
– Adjust the imager and lighting angles to optimize

 Quiet Zone (Margin) violations

Modulation

– A poor Quiet Zone may make it hard to locate a code

Verification prevents these errors

Poor quiet zone

Verifiers
Microscan’s LDP and DPM Verifiers provide complete reports to current
Data Matrix verification standards for printed and Direct Part Marks.
ISO/IEC 16022 • ISO/IEC 15415 • AS9132 • AIM DPM Guidelines • MIL-STD-130

© 2010 Microscan Systems, Inc.

Decodability
Example images on Direct Part Marks
Before

After

Effect of shiny surface: use diffuser

Before

After

Effect of surface structure: rotate 90°

Effect of low contrast: change reading angle

Effect of curved surface: use external line light

Effect of reading angle: change reading angle

Effect of concave surface: use dome light
© 2010 Microscan Systems, Inc.

© 2010 Microscan Systems, Inc.

Marking & Decoding 2D Symbologies
Conclusion
 Marking Methods
– Printed
– Chem Etch
– Direct Ink Jet

– Laser Anneal, Ablation, Etch
– Dot Peen

 Decoding a 2D symbology
– Locate, and then decode
– Minimum resolution (PPE)

 Maximizing Readability and Decodability
– Making a better image will improve reliability

© 2010 Microscan Systems, Inc.

Next session….
Applications and technology:
 Data Matrix applications in vertical markets
 Reading technology for applications

© 2010 Microscan Systems, Inc.

Thank you!

For More information
Website: www.microscan.com
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Online courses
Spec sheets
Technology brochures
Support self-help and support request form

Webinar feedback: www.microscan.com/feedback
Instructors:
Juan Worle, Technical Training Coordinator
Email: jworle@microscan.com
Matt Van Bogart, Global Channel Manager
Email: mvanbogart@microscan.com
© 2010 Microscan Systems, Inc.



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