TABLE OF CONTENTS
UPC Bar Code
How They Are Commonly Used … 4
Anatomy of A UPC (A) Bar Code … 5
UPC (A) Bar Code Glossary … 6
How It All Works … 7
Testing The Algorithm … 8
How They Are Commonly Used … 16
The Anatomy Of A QR Code … 17
QR Code Glossary … 18
How It All Works … 19
2D Bar Code / Data Matrix
How They Are Commonly Used … 10
Anatomy Of A Data Matrix … 12
Data Matrix Bar Code Glossary … 13
Benefits of The Data Matrix … 14
UPC BAR CODE
The UPC ( A ) bar code symbol, is one of the most
common applications of bar code technology and is
seen on products everywhere.
HOW THEY ARE
Bar codes are everywhere and they are used to identify
everything from auto parts to hospital patients. The
Universal Product Code is used to identify retail items in
virtually every store and market in the country.
THE ANATOMY OF A UPC (A) BAR CODE
95 MODULES WIDE!
UPC (A) BAR CODE GLOSSARY
UPC: Universal Product Code
MODULES: The vertical bars that make up the bar code symbol. Numbers are created by patterns of filled
and unfilled modules. 84 modules are used for digits, and 11 are used for the guards that define the symbols
GUARDS: Left and right guards mark the beginning and end of the symbol and the center guard marks the
division between the manufacturer and product codes.
MANUFACTURER CODE: Is made up of the first six digits and is distributed and managed by the UCC
(Uniform Code Council).
MANUFACTURER IDENTIFICATION NUMBER: Used to identify the particular numbering system used by the
ITEM NUMBER: Assigned to each product and is defined by the last five digits.
CHECKSUM: A single digit used for error checking.
HOW IT ALL WORKS
First, the scanner ﬂashes a laser across the
code reading the lines and spaces across. !
In a fraction of a second the scanner makes
several calculations to determine the
orientation of the code and then error checks
to make certain that the scan was valid. !
It does this by testing an algorithm against
the checksum digit.!
TESTING THE ALGORITHM
First the scanner sums the
digits in the odd positions !
Then it multiplies that !
result by three!
Next, it sums the even !
place digits !
And adds the two sums!
That result is divided by ten!
The remainder is subtracted from
ten to verify the checksum. If the
checksum doesn’t match, the
scanner reports an error and the
code must be re-scanned.!
2D BAR CODE / DATA MATRIX
Two dimensional bar codes are called so because the reader
scans both horizontally and vertically across the symbol,
unlike linear barcodes.
HOW THEY ARE
Along with the less popular PDF417 (actually stacked linear)
and Aztec symbologies, Data Matrix is commonly used in
healthcare. Because of its accuracy, efficiency and small
size, it works particularly well on patient wristbands and
medication labels, as it is less likely to distort around curves
and takes up less space, in addition to being highly
readable and accurate.
2D symbologies, like Data Matrix,
provide a consistent and reliable
means of labeling small objects.
THE ANATOMY OF A DATA MATRIX
DATA MATRIX BAR CODE GLOSSARY
MODULES: Small square cells that make up the bar code symbol. Usually, dark modules
represent a digital 1 and light represent 0.
FINDER PATTERN: Two adjacent, solid borders are designated the finder pattern. These borders
are used by the scanner to locate and orient the symbol and to correct distortion.
TIMING PATTERN: Two opposite adjacent pair of borders are constructed with alternating dark
and light cells and are designated as the timing pattern. This component gives the scanner
information about the symbol’s size.
DATA REGION: The actual data and error correction information is divided into regions in the
symbol which contain a pattern of modules in a consistent array.
QUIET ZONE: A clear space around the symbol.
BENEFITS OF THE
VERY EFFICIENT: Misread probability of 1/10.5 million (for the 3 of 9 symbol the probability
drops to 1/1.7 million).
SMALL: Almost 40X smaller than a 3 of 9 carrying the same data.
DEPENDABLE: Error correction capabilities (ECC200 method) allows accurate reads on symbols
with up to 60% damage.
FAXABLE: Data Matrix is also one of the few codes that are faxable. The outstanding capabilities
of ECC200 error correction allows even poorly resolved faxed images to be reliably scanned.
STORAGE CAPACITY: They are designed to encode up to 2335 alphanumeric characters,
though they have a recommended limit of 800 characters, actual best case is around 1200.
The Quick Response or QR code is a trademarked two-dimensional
barcode first designed for the automotive industry in Japan in 1994
by Denso Wave, a Toyota subsidiary. Almost a decade ago, it was
introduced to enable high-speed component scanning during the
HOW THEY ARE
Since then QR codes have become ubiquitous, showing
up on product packaging, billboards and bumper
stickers, in magazines and just about any place where
a consumer with a smartphone is likely to seek more
information about any topic, item or idea.
THE ANATOMY OF A QR CODE
QR CODE GLOSSARY
MODULES: square modules arranged on a grid. These modules form the components of the
code. Within the code the modules fall into two categories:
functional and encoding.
FUNCTIONAL MODULES: referring to those pieces that enable accessing the data
ENCODING MODULES: pieces used to store actual data
FINDER PATTERN: These are made up of alternating black and empty modules used to indicate
the position of the symbol’s internal components.
ALIGNMENT PATTERNS: looking much like smaller versions of the positional detection
indicators may occur in several places in the code depending on the code version.
ENCODING PORTION: consists of the information formatting areas and the data and error
QUIET ZONE: A clear space around the symbol
HOW IT ALL WORKS
Data is divided up into code blocks within the data
area, and each code block is sized so that it can
contain no more than 15 errors. This strategy
simplifies the algorithm, and interleaving the data in
the code blocks minimizes the possibility of an
unreadable code due to partial damage to symbol.
This also allows for some artistic license with adding
logos and other simple graphics to QR Codes.
QR Codes can contain four basic types of information:
numeric, alphanumeric, binary and Kanji.
The key to the success of QR Codes lies in the
use of Reed-Solomon error correction.
The QR Code bridges the gap between
the physical and virtual worlds.