A barcode is an optical, machine-readable, representation of data; the data usually describes something about the object that carries the barcode.

1. BARCODE
(INVENTION & EVOLUTION)

2. Definition
A barcode is an optical, machine-readable, representation of data; the data
usually describes something about the object that carries the barcode.
Barcodes systematically represented data by varying the widths and spacing
of parallel lines , referred to as linear or one-dimensional (1D). Later two-
dimensional (2D) codes were developed, using rectangles, dots, hexagons and
other geometric patterns, and it is usually called barcodes although they do
not use bars as such. Barcodes originally were scanned by special optical
scanners called barcode readers. Later applications software became
available for devices that could read images, such as smartphones with
cameras.

3. Who Invented Barcode ? (History of Barcodes)
Modern bar code began in 1948. Bernard Silver, a graduate student at Drexel
Institute of Technology in Philadelphia. A local food chain store owner had
made an inquiry to the Drexel Institute asking about research into a method
of automatically reading product information during checkout. Silver told his
friend Norman Joseph Woodland about the food chain president's request.
The problem fascinated Woodland and he began to work on the problem.
Woodland's first idea was to use ultraviolet light sensitive ink. The team built
a working prototype but decided that the system was too unstable and
expensive.

4. On October 20, 1949, Woodland and Silver filed their patent application for the
"Classifying Apparatus and Method", describing their invention as "article
classification...through the medium of identifying patterns".
The first patent for a bar code type product (US Patent #2,612,994) was issued to
inventors Joseph Woodland and Bernard Silver on October 7, 1952. The Woodland
and Silver bar code can be described as a "bull's eye" symbol, made up of a series of
concentric circles
Norman Joseph Woodland
Born September 6, 1921
Atlantic City, New Jersey
Died December 9, 2012 (aged 91)
Edgewater, Jersey

5. Bar code was first used commercially in 1966, however, it was soon realized that there
would have to be some sort of industry standard set. By 1970, the Universal Grocery
Products Identification Code or UGPIC was written by a company called Logicon Inc.
The first company to produce bar code equipment for retail trade use (using UGPIC)
was the American company Monarch Marking in 1970, and for industrial use, the
British company Plessey Telecommunications was also first in 1970. UGPIC evolved
into the U.P.C. symbol set or Universal Product Code, which is still used in the United
States. George J. Laurer is considered the inventor of U.P.C. or Uniform Product Code,
which was invented in 1973.
Bar Code - Commercial Use

6. In June of 1974, the first U.P.C. scanner was installed at a Marsh's supermarket in Troy,
Ohio. On June 26, 1974, the first product with a bar code was scanned at a check-out
counter. It was a 10-pack of Wrigley's Juicy Fruit chewing gum. The pack of gum wasn't
specially designated to be the first scanned product. It just happened to be the first item
lifted from the cart by a shopper whose name is long since lost to history. Today, the
pack of gum is on display at the Smithsonian Institution's National Museum of American
History.
A 10-pack of Wrigley Juicy Fruit gum was the first item scanned for its UPC in a grocery store 40 years ago in 1974.

7. If you look at a barcode, you probably can't make head or tail of it: you don't know
where one number ends and another one begins. But it's simple really. Each digit in the
product number is given the same amount of horizontal space: exactly 7 units. Then, to
represent any of the numbers from zero through nine, we simply color those seven units
with a different pattern of black and white stripes. Thus, the number one is represented
by coloring in two white stripes, two black stripes, two white stripes, and one black
stripe, while the number two is represented by two white stripes, one black stripe, two
white stripes, and two final black stripes
How barcodes represent the numbers 0-9

8. How do barcodes work?
All Barcodes look similar - at least when viewed from distance. They have the same
alternating black and white lines. There are 95 columns evenly spaced. Some columns
appear thicker when a group of columns are of same color, both black and white. See
the top of the barcode below.
when the laser light falls on this set of parallel lines the white lines reflect most of the
light while black lines don't. Now a computer can understand only two numbers -
either 0 or 1. So it treats dark lines as 1s and white lines as 0s.
The first line reflects none of the light (or very less light) - Hence assigned the digit 1. The
next line reflects almost all light - hence assigned 0. In the same manner all columns are
assigned the numbers. Total assignations - 95. Note that these numbers are different
from the one actually put below. After this, these 95 numbers are grouped in 15
different sections. 12 of these sections are used for the actual visible numbers and
remaining 3 act as guards - Left Guard, Center Guard and Right Guard. You can see that
in each bar code the left, the right and the center sections are similar.

9. The pattern for the right side is similar except that it has an even number of 1s. This helps
the computer to figure out which side is left/right, in case the product has been turned
upside down! There is one more check for this. All the codes for the left side begin with a
0 while those for the right side begin with a 1, leaving the guards.

10. 1. The very first number decides the type of product - Standard, weighted items,
pharmacy, coupons etc.
2. The next 5 sets of numbers tell who the manufacturer of the product is.
3. The next 5 sets of numbers tell the product code.
4. Finally the final digit is called Modulo check character. It is used for error checking. It is
an important number, and its functioning is explained below.
To get the Modulo check character:
Add all the digits at odd places. There are 11 digits (leaving the Modulo number)
So for the above figure it is
0+6+0+2+1+5 = 14.
Multiply it by 3 to get 42
Now add the even digits: 3 +0+0+9+4 = 16
Add both: 42 + 16 = 58.
Now the modulo check number is obtained by subtracting this from the next higher
multiple of 10. Here 60 - 58 = 2 --> The Modulo number.
This is how the scanner verifies that the code is correct or not.

11. Universal Product Code (UPC)
"UPC" stands for Universal Product Code. UPC bar codes were originally created to
help grocery stores speed up the checkout process and keep better track of inventory,
but the system quickly spread to all other retail products because it was so successful.
UPCs originate with a company called the Uniform Code Council (UCC). A
manufacturer applies to the UCC for permission to enter the UPC system. The
manufacturer pays an annual fee for the privilege. In return, the UCC issues the
manufacturer a six-digit manufacturer identification number and provides guidelines
on how to use it. You can see the manufacturer identification number in any standard
12-digit UPC code. The UPC symbol has two parts:
• The machine-readable bar code
• The human-readable 12-digit UPC number

12. The manufacturer identification number is the first six digits of the UPC number --
639382 in the image above. The next five digits -- 00039 -- are the item number. A
person employed by the manufacturer, called the UPC coordinator, is responsible
for assigning item numbers to products, making sure the same code is not used on
more than one product, retiring codes as products are removed from the product
line, etc. In general, every item the manufacturer sells, as well as every size package
and every repackaging of the item, needs a different item code.

13. The last digit of the UPC code is called a check digit. This digit lets the scanner
determine if it scanned the number correctly or not. Here is how the check digit is
calculated for the other 11 digits, using the code 63938200039 from "The Teenager's
Guide to the Real World" example shown above:
1. Add together the value of all of the digits in odd positions (digits 1, 3, 5, 7, 9 and
11). 6 + 9 + 8 + 0 + 0 + 9 = 32
2. Multiply that number by 3. 32 * 3 = 96
3. Add together the value of all of the digits in even positions (digits 2, 4, 6, 8 and 10).
3 + 3 + 2 + 0 + 3 = 11
4. Add this sum to the value in step 2. 96 + 11 = 107
5. Take the number in Step 4. To create the check digit, determine the number that,
when added to the number in step 4, is a multiple of 10. 107 + 3 = 110 The check
digit is therefore 3.

14. Each time the scanner scans an item, it performs this calculation. If the check digit it
calculates is different from the check digit it reads, the scanner knows that
something went wrong and the item needs to be rescanned.

15. Types of Barcodes
There are many types of barcodes that are used to track products, mail, and people.
Barcodes can be one dimensional or two dimensional. Nearly everyone has
purchased products that have one or more barcodes.
The Universal Product Code(UPC) is a one dimensional or linear barcode that is seen
by more people than any of the other types of barcodes. UPC symbols are required in
the retail industry and in the food service industry. When you purchase an item in a
retail store, you will see a UPC barcode that is printed on the outside of a product, or
a barcode that is printed on a barcode label which is affixed to a product. The UPC
has a fixed length of twelve digits and it uses numbers only.
Industry: Retail
Variations: UPC-A, UPC-E

16. EAN CODE (International Article Number also known as European Article Number,
which technically refers to EAN-13)
are also used to label consumer goods worldwide for point-of-sale scanning, primarily in
Europe. They look very similar to UPC codes, and the main distinction is their
geographical application. While EAN-13 (comprising 13 digits) is the default form factor,
you’ll find EAN-8 (covering 8 digits) barcodes on products where only limited space is
available, like small candies.
Industry: Retail
Variations: EAN-13, EAN-8, JAN-13, ISBN, ISSN

17. Code 39 is a linear barcode that is used for inventory tracking and other coding purposes
in manufacturing and other industries. Code 39 is a variable length code. This code can be
set at a length that fits the specific requirements of any kind of application. Code 39 is an
alphanumeric code that can encode digits zero through nine, upper case letters A through
Z, and a few special characters such as a dollar sign.
Industry: Automotive and Defense
Code 128 is a linear barcode that is used by the shipping and packaging industries. This
code is designed to be very compact. It uses the least amount of space of all of the one
dimensional types of barcodes. Code 128 is perfect for squeezing a lot of information
onto a shipping label. It can be used for alphanumeric or numeric barcodes. It can make
use of one hundred twenty eight ASCII characters.
Industry: Supply Chain

18. The Postal Numerical Encoding Technique barcode, or PostNET, is used by the United
States Postal Service. This linear barcode is used for zip codes that include the
mandatory five digit zip code and the optional four digit extension. PostNET makes it
easier to automate the sorting and delivery of mail.
QR Codes are 2D matrix barcodes with a strong consumer focus, often used in tracking
and marketing such as advertisements, magazines, and business cards. Free to use,
flexible in size, have a high fault tolerance, and have fast readability, though they can’t be
read with a laser scanner. QR codes support four different modes of data: numeric,
alphanumeric, byte/binary, and Kanji. QR code growth began in Japan and use continues
to grow today. They are public domain and free to use.
Industry: Retail, Entertainment and Advertising

19. PDF417 is a two dimensional barcode that is a portable data file which securely stores
large amounts of data. It can encode signatures, fingerprints, and photographs. Some
states use PDF417 barcodes on their driver licenses to encode names, addresses, driving
records, and driver photographs. Airline tickets and some packages also use this barcode.
Industry: Logistics and Government
Data matrix code is a two dimensional barcode that arranges black and white modules in
a square or rectangle.
Variation: Micro-Datamatrix
Industry: Electronics, Retail and Government

20. Aztec code is a two dimensional barcode that is used in a bulls eye pattern on a
square grid. This code is used by airlines for electronic boarding passes. This code is
also used on some railway tickets. Japan has started using an Aztec code stamp to
mark the passports of foreigners who visit Japan.
Industry: Transportation

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