BAR CODESSeminar Report Submitted in Partial Fulfillment of the

Requirement for the award of the degree of

BACHELOR OF TECHNOLOGYIN

ELECTRONICS & INSTRUMENTATION ENGINEERING(U. P. Technical University, Lucknow)

DEPARTMENT OF ELECTRONICS & INSTRUMENTATIONENGINEERING

IIMT COLLEGE OF ENGINEERING GREATER NOIDA

ByVIPIN KUMAR

E.I. Final YearRoll No. 0721632059

ACKNOWLEDGEMENT

First and foremost I would like to thank the almighty, who bestowed upon me the patience, strength and ability to embark upon this work and carry it to its completion. It is a matter of great pride and privilege for me to have the esteemed supervision of Ms. Taslima Ahmed as the seminar coordinator. I would render this acknowledgement as incomplete if I don’t mention the able guidance of Mr. Jitendra Kumar (seminar guide).I would always be thankful to him for the critical analysis of my seminar. I am in debt to him for his suggestions that made me thinking.

I am thankful to Mr. Umesh Kumar (HOD) Electronics department, for providing the internet facility in college premises which served as a boon in material collection .A special thanks to all the faculty members and the non teaching staff for their invaluable support.

Vipin Kumar E.I. Final Year

IIMT College of Engineering

CERTIFICATE

THIS IS TO CERTIFY THAT Mr. Vipin KumarOF B.TECH FINAL YEAR, ELECTRONICS & INSTRUMENTATION DELIVERED A SEMINAR ON “BARCODES” ON 06 /11 /2009 ACCORDING TO THE U.P. TECHNICAL UNIVERSITY CURRICULUM. HIS PERFORMANCE IN THE SEMINAR WAS EXCELLENT/VERY GOOD/SATISFACTORY.

Mr.Jitendra Kumar Ms. Taslima Ahmed SEMINAR GUIDE SEMINAR COORDINATOR

Mr. Umesh Kumar

Head of Department

History

While it may seem like barcodes have been with us forever, barcodes didn’t really make an impact until the 1970’s. It wasn’t until 1974 that the first barcode scanner was employed and the first product barcoded.

  In 1932, Wallace Flint suggested that an automated retail checkout system might be feasible.  While his concept was deemed unworkable, Flint continued to support the idea of automated checkout throughout his career.  In fact, Flint, who went on to become the vice-president of the association of food chains some 40 years later, was instrumental in the development of the UPC code.

 

Initial Uses of Barcodes

In 1948, a local food chain store owner approached Drexel Institute of Technology in Philadelphia asking about research into a method of automatically reading product information during checkout. Bernard Silver, a graduate student at Drexel Institute, along with fellow graduate student Norman Joseph Woodland, teamed together to develop a solution.

On October 20, 1949, Woodland and Silver succeeded in building a working prototype describing their invention as “article classification…through the medium of identifying patterns”.  On October 7, 1952, they were granted a patent (US Patent #2,612,994) for their “Classifying Apparatus and Method”. Efforts to develop a working system accelerated in the 1960’s.

First Commercial Use

Bar coding was first used commercially in 1966, but to make the system acceptable to the industry as a whole there would have to be some sort of industry standard. By 1970, Logicon Inc. had developed the Universal Grocery Products Identification Code (UGPIC). The first company to produce barcode equipment for retail trade using (using UGPIC) was the American company Monarch Marking (1970), and for industrial use, the British company Plessey Telecommunications (1970).

In 1972, a committee was formed within the grocery industry to select a standard code to be used in the industry. IBM proposed a design, based upon the UGPIC work and similar to today’s UPC code. On April 3, 1973, the committee selected the UPC symbol (based on the IBM proposal) as the industry standard. George J. Laurer is considered the inventor of U.P.C. or Uniform Product Code.

First UPC Scanner 

In June of 1974, the first U.P.C. scanner was installed at a Marsh’s supermarket in Troy, Ohio. The first product to have a barcode was Wrigley’s Gum.

INDEX

CHAPTER 1.INTRODUCTION 1.1 WHAT ARE BARCODES? 1.2 BARCODES BASIC 1.3 TYPES OF BARCODES 1.4 BARCODES SYMBOL CHARACTERISTICS CHAPTER 2.ANATOMY OF BARCODE 2.1 NUMBER SYSTEM CHARACTER 2.2 THE THREE GUARD BANDS 2.3 MANUFACTURER CODE 2.4 PRODUCT CODE 2.5 CHECK DIGIT 2.6 WHERE IS THE PRICE? CHAPTER 3.BARCODE STANDARDS 3.1 UNIVERSAL PRODUCT CODE (U.P.C.) 3.2 EUROPEAN ARTICLE NUMBER (E.A.N.) CHAPTER 4.METHODS TO READ BARCODES 4.1 BARCODE READER 4.2 TYPES OF BARCODE READERS 4.3 BARCODES SCANNER

CHAPTER 5. BARCODES PRINTERS AND GENERATORS 5.1 BARCODE PRINTER 5.2 BARCODE GENERATOR

CHAPTER 6.USES AND BENEFITS OF BARCODES 6.1 USES OF BARCODES 6.2 BENEFITS OF BARCODES

CHAPTER 7.REFERENCE

CHAPTER 8.SUMMARY

1. Introduction

1.1 What are barcodes?

Barcodes are those ever-familiar "bars" and "numbers" on virtually everything. In 1973, Barcodes quietly strolled into our world. In just over 25 years, Barcode has literally taken over the world. Now there's a barcode for virtually everything.

There's short barcodes, and tall barcodes.

There's postal barcodes and international barcodes.

There's 2-D barcodes. And there's even barcodes for the humble "bumble-bee". From letters, to cokes, from fishes to smokes - it's "clothed" with friendly Barcode.

A barcode is an optical machine-readable representation of data. Originally, barcodes represented data in the widths (lines) and the spacings of parallel lines, and may be referred to as linear or 1D (1 dimensional) barcodes.

They also come in patterns of squares, dots, hexagons and other geometric patterns within images termed 2D (2 dimensional) matrix codes. Although 2D systems use symbols other than bars, they are generally referred to as barcodes as well. Barcodes can be read by optical scanners called barcode readers, or scanned from an image by special software.

The primary barcode used in the United States is the UPC (Universal Product Code) barcode. The UPC is also the "original" barcode. The UPC was designed for the grocery industry. Because of the large number of items normally "checked-out" at the grocery store, a method was needed to speed up and eliminate "human" cashier errors. In 1973, the UPC barcode was born.

To the average person, the barcode looks confusing and complex, but to a "bar-coded" friendly computer, it's actually very simple.

1.2 Bar codes basic

Bar codes provide a simple and inexpensive method of encoding text information that is easily read by inexpensive electronic readers.

Bar coding also allows data to be collected rapidly and with extreme accuracy. A bar code consists of a series of parallel, adjacent bars and spaces. Predefined bar and space patterns are used to encode small strings of character data into a printed symbol.

Bar codes can be thought of as a printed type of the Morse code with narrow bars (and spaces) representing dots, and wide bars representing dashes.

A bar code reader decodes a bar code by scanning a light source across the bar code and measuring the intensity of light reflected back by the white spaces. The pattern of reflected light is detected with a photodiode which produces an electronic signal that exactly matches the printed bar code pattern. This signal is then decoded back to the original data by inexpensive electronic circuits.

Due to the design of most bar code it does not make any difference if you scan a bar code from right to left or from left to right.

The basic structure of a bar code consists of a leading and trailing quiet zone, a start pattern, one or more data characters, optionally one or two check characters and a stop pattern.

There are a variety of different types of bar code encoding schemes, each of which were originally developed to full fill a specific need in a specific industry.

The different symbologies have different capabilities for encoding data. For example the UPC symbology used to identify retail products always contains 12 numeric digits.

These type of bar codes are called "linear symbologies" because they are made up of a series of lines of different widths. Most commercially available bar code scanners are able to read all of the different linear bar code symbologies therefore you do not need different readers for different types of bar codes.

New "2-Dimensional" bar code symbologies like EAN, Aztec Code etc. are also now available that can encode several thousand bytes of data in a single bar code symbol including text or binary data. The newer 2D bar code symbologies typically require special bar code readers that are designed specifically for reading them.

The primary purpose of a bar code is to identify something by labeling the item with a bar code containing a unique number or character string.

Bar codes are typically used with a database application where the data encoded in the bar codes is used as an index to a record in the database that contains more detailed information about the item that is being scanned.

For example, when a checkout clerk scans a bar code on a product in a grocery store, the bar code data is fed to a computer that looks up the information in a central database and returns more detailed information about the item that was scanned including possibly a description of the item and a price. By using bar codes, the grocery store does not need to put a price tag on each item in the store and they can also change the price for a particular item by modifying a single entry in the central database. They can also track how much of a product is currently in stock so that they know when to re-order more of each item as the number of items in stock falls.

Bar codes also provide a quick and error free means for inputting the data into an application running on a computer.

By using bar codes, the potential for errors from manual data input is eliminated.

Another typical application for bar codes is therefore for inputting data without having to type. For example you could encode name or address data in a bar code on an ID badge and then scan the ID badges to input a persons name into a computer program instead of typing the information.

1.3 Types of barcodes

A) Linear or one dimensional barcodes

B) Matrix or two dimensional barcodes

a) Linear barcodes:

These type of bar codes are called "linear symbologies" because they are made up of a series of lines of different widths

ex: U.P.C.( Universal Product Code)

code 128 code 39

b) Matrix (2D) barcodes:

A matrix code, also known as a 2D barcode or simply a 2D code, is a two-dimensional way of representing information. It is similar to a linear (1-dimensional) barcode, but has more data representation capability.

Ex: E.A.N(European Article Number)

First, Second and Third Generation Barcodes

GTIN-12 number encoded in UPC-A barcode symbol. First and last digit are always placed outside the symbol to indicate Quiet Zones that are necessary for barcode scanners to work properly

EAN-13 (GTIN-13) number encoded in EAN-13 barcode symbol. First digit is always placed outside the symbol, additionally right quiet zone indicator (>) is used to indicate Quiet Zones that are necessary for barcode scanners to work properly.

1.4 Bar Code Symbol Characteristics

1. Magnification

The magnification (size) of the bar code symbol is determined by the X-dimension (one narrow module width) in relation to a nominal size.

The allowable magnification range depends on the symbol type and the intended scanning environment. Reliability of scanning is always enhanced by selecting a magnification higher than the minimum.

To print an accurate and high quality bar code symbol a number of factors, such as the printing process, ink quality, and substrate, must be taken into consideration.

2. Bar Height

Once the magnification of the bar code symbol has been determined, for EAN/UPC Bar Code symbols it is important to ensure that the height remains in proportion to the magnification, and does not drop below the minimum specified.

3. Quiet Zones (Light Margins)

The Quiet Zones (Light Margin) of the bar code symbol are the solid, light areas before the first bar and after the last bar. These areas are extremely important as they allow the scanner to recognise the beginning and end of the bar code symbol.

Any obstruction or reduction in the Quiet Zones will most likely result in scanning difficulties. The minimum size required for the Quiet Zones depends on the magnification of the bar code symbol.

It is recommended to allow slightly more than the minimum required Quiet Zones to allow for any possible ink spread or plate registration issues.

4. Colours

The colours and type of ink you choose for your bar code symbols is very important. As a scanner reads a bar code symbol using an infrared light source it sees the symbol differently to the human eye.

As a result, some colour combinations and ink types are unsuitable for scanning because they do not provide sufficient contrast between the dark bars and the light background, or they provide a much too high reflectance value.

The most suitable and reliable colour combination is black bars on a white background. However, as a general rule, the background of the bar code symbol can be a light, warm colour that does not contain any black (such as yellow or light orange), and the bar colour can be a dark, cool colour that has no, or low, red content (such as dark blue or dark green).

5. Substrate

The substrate (the material the bar code symbol is printed on) is very important. If unsuitable this can cause scanning difficulties. Different packaging materials reflect light differently, which can have an effect on the scanning ability of the bar code symbol.

This is especially evident on transparent and translucent packages where the background is not printed.

For printing bar code symbols it is recommended that you avoid the following:

• High gloss substrates

• Transparent or semi-transparent backgrounds

• Transparent wrappers over the printed bar code symbol if necessary to print onto a highly reflective (flexible) substrate, we recommend the following:

• Increase the magnification of the bar code symbol to between 105% and 120% (X-dimension 0.35mm - 0.40mm)

• Increase the amount of Bar Width Reduction

• Make the background of the symbol as dense and less reflective as possible. To do this you may try the following:

• If you are not using wet inks, print two background layers. This may be two layers of the one colour, or you may use all light colours in the print run (e.g. white and yellow)

• Use a less viscous ink that will provide maximum coverage and density

6. Bar Widths and Print Quality

Always ensure that the print quality of the bar code symbol is of a high standard. Ensure that the bars in the symbol are clearly defined, watch for voids or smudging, and avoid flecks in the background colour.

Maintaining acceptable print quality and consistent print gain (ink spread) requires regular ongoing checks.

2. Anatomy of barcodes

Note: The computer does not read the numbers underneath the barcode. These Human Readable (HR) numbers are printed so a "human" can easily read the barcode, if necessary.

2.1 Number System Character:

This number is a UPC system number that characterizes specific types of barcodes. In a UPC barcode it is normally on the left of the barcode. The actual "barcode" (the "bars" and "spaces") is the first "barcode" after the first "guard bar". The Number System Character is the blue box on the "Anatomy of a Barcode".

Codes of the Number System Character:

0 - Standard UPC number. 1 - Reserved. 2 - Random weight items like fruits, vegetables, and meats, etc. 3 - Pharmaceuticals 4 - In-store code for retailers. 5 - Coupons 6 - Standard UPC number. 7 - Standard UPC number.

8 - Reserved. 9 - Reserved.

2.2 Three Guard Bars:

There are "3 guard bars".

They are located at the beginning, middle and end. The beginning and ending guard bars are encoded as a "bar-space-bar" or 101. The middle guard bar is encoded as "space-bar-space-bar-space" or 01010.

The guard bars "tell" the computer-scanner when the manufacturer and product code begin and end. For example, when the computer-scanner reads the first "101" or guard bar, the computer knows the next series of numbers is either the manufacturer or product code. And when the computer reads the "01010" or middle guard bar, the computer knows another number is coming. The 3 guard bars are highlighted with a green box on the "Anatomy of a Barcode".

Also, the first guard bar scanned is used by the computer to calculate the "width" of one unit.

2.3 Manufacturer Code:

This is a five digit number specifically assigned to the manufacturer of the product. The manufacturer codes are maintained and assigned by the Uniform Code Council (UCC). Every product the manufacturer makes, carries the same manufacturer code. For example, the manufacturer code for Kellogg's is 38000. Every product Kellogg makes carries 38000 as the manufacturer code in the bar code. The manufacturer code is yellow on the "Anatomy of a Barcode".

2.4 Product Code:

The product code is a five digit number that the manufacturer assigns for a particular product. Every different product and every different packaging or size, gets a unique product code.

For instance, a 16oz bottle of coke gets a different product code than a 24 oz bottle of coke.

For example: Kellogg's 13.5 oz Rice Krispies barcode is 38000 90530 — the 38000 is the manufacturer code for Kellogg and the 90530 is the product code for 13.5oz Rice Krispies. The product code is orange on the "Anatomy of a Barcode".

2.5 Check digit:

Also called the "self-check" digit. The check digit is on the outside right of the bar code. The check digit is an "old-programmer's trick" to validate the other digits (number system character, manufacturer code, and product code) were read correctly. The check digit is red on the "Anatomy of a Barcode".

How the computer calculates the check digit:

1. Add all the odd digits. In our "Anatomy of a Barcode" we would add 0 (yes, you include the number system character digit) + 2 + 4 + 6 + 8 + 0 = 20

2. Multiply the sum of step 1 by 3. Our example would be 20 x 3 = 60. 3. Add all the even numbers. In our "Anatomy of a Barcode" we would add 1 + 3 + 5 + 7 + 9

= 25. You do not include the 5 or the check digit because that's what you are calculating. 4. Now add the result from step 2 and step 3. 60 + 25 = 85. 5. The check digit is the number needed to add to step 4 to equal a multiple of 10. 85 + 5 = 90.

5 is the check digit in our example.

You'll notice the price was NOT included in the barcode.

2.6 Where is the price?

The price is kept in the store's centralized computer database. The store's "item database" contains a record for every item the store sells. The item record is "keyed" by manufacturer code and product code (same numbers as on the barcode). The price is kept for each item in this database. When the item is scanned by the employee, a computer program reads the barcode. It then converts the "bars and spaces" into the manufacturer and product "digital number". Using the manufacturer and product "digital number", the program reads the store's "item database". It then retrieves the price from the "item database" for that item. When a price changes, all the store has to do is update it once in the stores centralized database.

3. Bar codes standards

3.1 Universal Product Code (U.P.C.)

The Universal Product Code (UPC) is a barcode symbology (i.e., a specific type of barcode), that is widely used in Canada and the United States for tracking trade items in stores.

Current code:

In the UPC-A barcode, each digit is represented by a seven-bit sequence, encoded by a series of alternating bars and spaces. Guard bars, shown in green, separate the two groups of six digits.

The following tables are the left and right side codes matching the corresponding numbers, separated into the seven single units.

The UPC encodes 12 decimal digits as SLLLLLLMRRRRRRE, where S (start) and E (end) are the bit pattern 101, M (middle) is the bit pattern 01010 (called guard bars), and each L (left) and R (right) are digits, each one represented by a seven-bit code. This is a total of 95 bits.

The UPC has only numerals, with no letters or other characters. The first digit L is the prefix. The last digit R is an error correcting check digit, allowing some errors in scanning or manual entry to be detected. UPC data structures are a component of GTINs (Global Trade Item Numbers). All of these data structures follow the global GS1 standards.

The bar-and-space patterns for each digit 0–9 are as follows:

Digit L Pattern R Pattern0 0001101 11100101 0011001 11001102 0010011 11011003 0111101 10000104 0100011 10111005 0110001 10011106 0101111 10100007 0111011 10001008 0110111 10010009 0001011 1110100

Before the Middle guard bars, a binary 1 is indicated by a bar, while a 0 is indicated by a space. After the Middle guard bars, however, the patterns are optically inverted. In other words, a 1 is now indicated by a space, and a 0 is now indicated by a bar.This inversion enables the code to be scanned uniquely from either direction, left-to-right or right-to-left.

Prefixes:

0, 1, 6, 7, 8, and 9: for most products.

2 : Reserved for local use(store/warehouse),for items sold by variable weight. Variable-weight item, such as fresh fruit and vegetables are assigned a UPC by the store, if they are packed there.

3: Drugs by National Drug Code number.

4: reserved for local use, often for loyalty cards or stores coupons.

5: Coupons the manufacture code is the LLLLL, the first three RRR are a family code (set by manufacture), and the next 2 RR are a coupon code. This 2-digit code determines the amount of discount.

By prefixing these with a 0, they become EAN-13 rather than UPC-A. This does not change the check digit. All point-of-sale systems can now understand both equally.

Other variations:

UPC in its most common usage technically refers to UPC-A. Other variants of the UPC exist.

UPC-B is a 12-digit version of UPC with no check digit, developed for the National Drug Code and National Health Related Items Code.

UPC-C is a 12-digit code with a check digit.

UPC-D is a variable length code (12 digits or more) with the 12th digit being the check digit. These versions are not in common use.

UPC-5 is a 5-digit supplement to the UPC code used to indicate suggested retail price for books.

As the UPC has become technologically obsolete, it is expected that UPC-B and UPC-C will disappear from common use by the 2010s. The UPC-D standard may be modified into EAN 2.0 or be phased out entirely.

3.2 European Article Number (E.A.N.)

GTIN-13 number encoded in EAN-13 barcode. First digit is always placed outside the symbol, additionally right quiet zone indicator (>) is used to indicate Quiet Zones that are necessary for barcode scanners to work properly.

An EAN-13 barcode (originally European Article Number) is a bar coding standard which is a superset of the original 12-digit Universal Product Code (UPC) system developed in the United States.

The EAN-13 barcode is defined by the standards organisation GS1. The numbers encoded in EAN-13 bar codes are product identification numbers which are called Japanese Article Number (JAN) in Japan. All the numbers encoded in UPC and EAN barcodes are known as Global Trade Item Numbers (GTIN), and they can be encoded in other GS1 barcode.

The EAN-13 barcodes are used worldwide for marking products often sold at retail point of sale. The less commonly used EAN-8 barcodes are used also for marking retail goods; however, they are usually reserved for smaller items, for example confectionery.

2-digit (EAN 2) and 5-digit (EAN 5) supplemental barcodes may be added for a total of 14 or 17 data digits. These are generally used for periodicals (to indicate the serial number) and books (to indicate the selling price) respectively.

Encoding of data digits into EAN-13

Encoding EAN-13

The numbers of code L The number of code G

The numbers of code R

To encode an EAN-13 barcode, the digits are first split into 3 groups, the first digit, the first group of 6 and the last group of 6.

The first group of six is encoded using a scheme whereby each digit has two possible encodings, one of which has even parity and one of which has odd parity. The first digit is encoded by selecting a pattern of choices between these two encodings for the next six digits, according to the table below.

All digits in the last group of six digits are encoded using a single set of patterns which are the same patterns used for UPC.

If the first digit is zero, all digits in the first group of six are encoded using the patterns used for UPC, hence a UPC barcode is also an EAN-13 barcode with the first digit set to zero.

Structure of EAN-13

First digit First group of 6 digits Last group of 6 digits0 LLLLLL RRRRRR1 LLGLGG RRRRRR2 LLGGLG RRRRRR3 LLGGGL RRRRRR4 LGLLGG RRRRRR5 LGGLLG RRRRRR6 LGGGLL RRRRRR7 LGLGLG RRRRRR8 LGLGGL RRRRRR9 LGGLGL RRRRRR

Encoding of the digits

Digit L-code G-code R-code0 0001101 0100111 11100101 0011001 0110011 11001102 0010011 0011011 11011003 0111101 0100001 10000104 0100011 0011101 10111005 0110001 0111001 10011106 0101111 0000101 10100007 0111011 0010001 10001008 0110111 0001001 10010009 0001011 0010111 1110100

Note: Entries in the R-column are bitwise complements of the respective entries in the L-column. Entries in the G-column are the entries in the R-column reversed. See pictures of all codes against a colored background.

4. Methods to read barcodes

4.1 Barcode reader

A typical handheld barcode scanner

A barcode reader (or barcode scanner) is an electronic device for reading printed barcodes. Like a flatbed scanner, it consists of a light source, a lens and a light sensor translating optical impulses into electrical ones. Additionally, nearly all barcode readers contain decoder circuitry analyzing the barcode's image data provided by the sensor and sending the barcode's content to the scanner's output port.

4.2 Types of barcode readers

Methods

Scanning methods are distinguished by the amount of operator manipulation required:

Pen or wand-type readers: requires the operator to swipe the pen over the code.

Semi-automatic handheld readers: The operator need not swipe, but must at least position the reader near the label

Fix-mount readers for automatic reading: The reading is performed laterally passing the label over the reader. No operator is required, but the position of the code target must coincide with the imaging capability of the reader.

Reader gates for automatic scanning: The position of the code must be just under the gate for short time, enabling the scanner sweep to capture the code target successfully.

The reader types can be distinguished as follows:

Pen type readers:

Pen type readers consist of a light source and a photodiode that are placed next to each other in the tip of a pen or wand. To read a bar code, the tip of the pen moves across the bars in a steady motion.

The photodiode measures the intensity of the light reflected back from the light source and generates a waveform that is used to measure the widths of the bars and spaces in the bar code.

Dark bars in the bar code absorb light and white spaces reflect light so that the voltage waveform generated by the photo diode is a representation of the bar and space pattern in the bar code.

This waveform is decoded by the scanner in a manner similar to the way Morse code dots and dashes are decoded.

Laser scanners:

Laser scanners work the same way as pen type readers except that they use a laser beam as the light source and typically employ either a reciprocating mirror or a rotating prism to scan the laser beam back and forth across the bar code. As with the pen type reader, a photodiode is used to measure the intensity of the light reflected back from the bar code.

In both pen readers and laser scanners, the light emitted by the reader is tuned to a specific frequency and the photodiode is designed to detect only this modulated light of the same frequency.

CCD Readers:

CCD readers (also referred to as LED scanner) use an array of hundreds of tiny light sensors lined up in a row in the head of the reader.

Each sensor measures the intensity of the light immediately in front of it. Each individual light sensor in the CCD reader is extremely small and because there are hundreds of sensors lined up in a row, a voltage pattern identical to the pattern in a bar code is generated in the reader by sequentially measuring the voltages across each sensor in the row.

The important difference between a CCD reader and a pen or laser scanner is that the CCD reader is measuring emitted ambient light from the bar code whereas pen or laser scanners are measuring reflected light of a specific frequency originating from the scanner itself.

Camera-Based Readers:

2D imaging scanners are the fourth and newest type of bar code reader currently available.

They use a small video camera to capture an image of a bar code. The reader then uses sophisticated digital image processing techniques to decode the bar code.

Video cameras use the same CCD technology as in a CCD bar code reader except that instead of having a single row of sensors, a video camera has hundreds of rows of sensors arranged in a two dimensional array so that they can generate an image.

Omni-Directional Barcode Scanners:

Omni-directional scanning uses "series of straight or curved scanning lines of varying directions in the form of a starburst, a lissajous pattern, or other multiangle arrangement are projected at the symbol and one or more of them will be able to cross all of the symbol's bars and spaces, no matter what the orientation."

Omni-directional scanners almost all use a laser. Unlike the simpler single-line laser scanners, they produce a pattern of beams in varying orientations allowing them to read barcodes presented to it at different angles. Most of them use a single rotating polygonal mirror and an arrangement of several fixed mirrors to generate their complex scan patterns.

Omni-directional scanners are most familiar through the horizontal scanners in supermarkets, where packages are slid across a glass or sapphire window.

Omni-directional scanners are also better at reading poorly printed, wrinkled, or even torn barcodes.

4.3 barcodes scanner:

How a computer-scanner does read a barcode?

A single barcode number is actually seven units. A unit is either black or white. A unit that is black would display as a "bar". A unit that is white would display as a "space". Another way of writing a barcode unit is "1" for a single unit "black bar" and "0" for a single unit "white space". For instance, the number "1" is composed of the seven units, "0011001" or "space-space-bar-bar-space-space-bar". Remember, a single barcode number requires seven units.

Also, on a UPC barcode the same numbers on the left-hand side (the Manufacturer Code) is coded different than the numbers on the right-hand side (Product Code). The left side numbers are actually the "inverted" or "mirrored" codes of the right side numbers, for instance what is a "bar" on the right-side, is a "space" on the left-side. The right-side codes are called "even parity" codes because there is an even number of "black bar" units.

For instance the right-side "6" is "101000" - 2 even-numbered "black bar" units. The left-side is called "odd-parity" because there are an odd number of “black bar” units. For instance, the left-side "6" is "0101111" - 5 odd-numbered "black bar" units. Having different coded numbers for each side allows the barcode to be scanned in either direction.

5. Bar codes printers and generator;

5.1 Barcode printer

A barcode printer

A barcode printer (or bar code printer) is a computer peripheral for printing barcode labels or tags that can be attached to physical objects.

Barcode printers are commonly used to label cartons before shipment, or to label retail items with UPCs or EANs.

The most common barcode printers employ one of two different printing technologies. Direct thermal printers use a print head to generate heat that causes a chemical reaction in specially designed paper that turns the paper black.

Thermal transfer printers also use heat, but instead of reacting the paper, the heat melts a waxy or resin substance on a ribbon that runs over the label or tag material. The heat transfers ink from the ribbon to the paper. Direct thermal printers are generally less expensive, but they produce labels that can become illegible if exposed to heat, direct sunlight, or chemical vapours.

Barcode printers are designed for different markets. Industrial barcode printers are used in large warehouses and manufacturing facilities. They have large paper capacities, operate faster and have a longer service life. For retail and office environments, desktop barcode printers are most common.

5.2 barcode generator:

There are various softwares available for generating bar codes. Depending upon the use one can use any of these available softwares.

Ex:

Barcode Studio 2 by Shortcut Software is a comprehensive program for barcodes. It helps you create, export, import, print and archive 17 different types of barcodes.

Barcode Studio 2 makes professional quality barcodes and several enterprise customers have made it their company barcoding solution.

Barcode Studio 2 supports UPC A, UPC E, ITF, Code 128, EAN 13, EAN 8 etc.

6. Uses and Benefits

6.1 Uses of barcodes:

Barcodes — especially the UPC — have slowly become an essential part of modern civilization. Their use is widespread, and the technology behind barcodes is constantly improving. Some modern applications of barcodes include:

Almost every item purchased from a grocery store, department store, and mass merchandiser has a UPC barcode on it. This greatly helps in keeping track of a large number of items in a store and also reduces instances of shoplifting involving price tag swapping, although shoplifters can now print their own barcodes.

The tracking of item movement, including rental cars, airline luggage, nuclear waste, mail and parcels.

Entertainment event tickets can have barcodes that need to be validated before allowing the holder to enter sports arenas, cinemas, theatres, fairgrounds, transportation etc. This can allow the proprietor to identify duplicate or fraudulent tickets more easily.

Used on automobiles, can be located on front or back.

Some 2D barcodes embed a hyperlink to a web page. A capable cell phone might be used to read the barcode and browse the linked website.

At the turn of the century, many artists started using barcodes in art, such as Scott Blake's Barcode Jesus.

6.2 Benefits of barcodes:

In point-of-sale management, the use of barcodes can provide very detailed up-to-date information on key aspects of the business, enabling decisions to be made much more quickly and with more confidence. For example:

Fast-selling items can be identified quickly and automatically reordered to meet consumer demand,

Slow-selling items can be identified, preventing a build-up of unwanted stock,

The effects of repositioning a given product within a store can be monitored, allowing fast-moving more profitable items to occupy the best space,

Historical data can be used to predict seasonal fluctuations very accurately.

This technology also enabled the profiling of individual consumers, typically through a voluntary registration of discount cards. While pitched as a benefit to the consumer, this practice is considered to be potentially dangerous by privacy advocates.

Besides sales and inventory tracking, barcodes are very useful in shipping/receiving/tracking.

When a manufacturer packs a box with any given item, a Unique Identifying Number (UID) can be assigned to the box.

A relational database can be created to relate the UID to relevant information about the box; such as order number, items packed, qty packed, final destination, etc…

The information can be transmitted through a communication system such as Electronic Data Interchange (EDI) so the retailer has the information about a shipment before it arrives.

Tracking results when shipments are sent to a Distribution Center (DC) before being forwarded to the final destination.

When the shipment gets to the final destination, the UID gets scanned, and the store knows where the order came from, what's inside the box, and how much to pay the manufacturer.

The reason barcodes are business-friendly is that the scanners are relatively low cost and extremely accurate compared to key-entry, with only about 1 substitution error in 15,000 to 36 trillion characters entered.[10] The exact error rate depends on the type of barcode.

Chapter 7: reference :

1. Roger C. Palmer. The Bar Code Book.

Automating Management Information Systems: Barcode Engineering and Implementation – Harry E. Burke, Thomson Learning, ISBN 0-442-20712-3

Automating Management Information Systems: Principles of Barcode Applications – Harry E. Burke, Thomson Learning, ISBN 0-442-20667-4

The Bar Code Book – Roger C. Palmer, Helmers Publishing, ISBN 0-911261-09-5, 386 pages

The Bar Code Manual – Eugene F. Brighan, Thompson Learning, ISBN 0-03-016173-8 Handbook of Bar Coding Systems – Harry E. Burke, Van Nostrand Reinhold Company,

ISBN 978-0-442-21430-2, 219 pages Information Technology for Retail:Automatic Identification & Data Capture Systems -

Girdhar Joshi, Oxford University Press, ISBN 0-19-569796-0, 416 pages Lines of Communication – Craig K. Harmon, Helmers Publishing, ISBN 0-911261-07-9,

425 pages Punched Cards to Bar Codes – Benjamin Nelson, Helmers Publishing, ISBN 0-911261-12-

5, 434 pages Revolution at the Checkout Counter: The Explosion of the Bar Code – Stephen A. Brown,

Harvard Univ Press, ISBN 0-674-76720-9 Reading Between The Lines – Craig K. Harmon and Russ Adams, Helmers Publishing,

ISBN 0-911261-00-1, 297 pages The Black and White Solution: Bar Code and the IBM PC – Russ Adams and Joyce Lane,

Helmers Publishing, ISBN 0-911261-01-X, 169 pages Sourcebook of Automatic Identification and Data Collection – Russ Adams, Van Nostrand

Reinhold, ISBN 0-442-31850-2, 298 pages

8. summary: