Working of barcode reader Presentation - Unitedworld School of Business

7/28/2019 Working of barcode reader Presentation - Unitedworld School of Business

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Working of Barcode Reader


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What is Barcode??

Barcodes are simply a set of symbols used to representalpha-numeric information instead of seeing a number 1,

or letter A, you would see a series of black and white

bars in various combinations and in different widths.

These are used to encode data. The data encoded in such

bars can be decoded again to represent it in human readable

form.


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What is Barcode Reader??

A barcode reader (orbarcode scanner) is an electronicdevice 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.


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Brief History

As far back as the 1960s, barcodes were used in industrial

work environments. Some of the early implementations of

barcodes included the ability identify rail road cars.

In the early 1970s, common barcodes started appearing ongrocery shelves. To automate the process of identifying

grocery items, UPC barcodes were placed on products.

Today, barcodes are just about everywhere and are used for

identification in almost all types of business.


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Working:

A bar code consists of a series of parallel, adjacent barsand spaces. Symbologies are used to encode small strings

of character data into a printed symbol.

A bar code reader decodes a bar code by scanning a light

source across the bar code and measuring the intensity oflight 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 backto the original data by electronic circuit.


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Pen type readers and Laser Scanners

Pen type readers consist of a light source and a photo diode thatare placed next to each other in the tip of a pen or wand.

To read a bar code, you drag the tip of the pen across all the bars

in a steady even motion. The photo diode measures the intensity

of the light reflected back from the light source and generates awaveform 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 an exact duplicate 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.


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CCD Readers

CCD (Charge Coupled Device) readers use an array ofhundreds of tiny light sensors lined up in a row in the head

of the reader. Each sensor can be thought of as a single

photo diode that 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 thevoltages across each sensor in the row.


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Camera based Readers

The newest type of bar code reader currently available arecamera-based readers that 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 cangenerate an image.


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Interfacing a Barcode reader to a PC


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Interfacing

Bar code readers are available with two types of output -either "keyboard wedge" output or RS232 output.

The bar code readers with keyboard wedge output plug

directly into the keyboard port on your PC .

The other option is RS232.With this type of bar code reader

we can connect available serial port on the back of PC.


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Why use Barcodes??

When barcodes are used in the business process,procedures are automated to increase productivity andreduce human error.

Whenever there is a need to accurately identify or tracksomething, bar-coding should be used. For example, in adata entry work environment, workers may be required toenter an enormous amount of data into a customer databasesystem.

Instead of manually typing a customer identification

number into a database, if the information is contained in abarcode, a data entry operator may scan it in. This wouldincrease automation and reduce human error.


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Barcode types and use:

The type of barcode to use for a particular situationdepends upon:

The use.

The data encoded in the barcode.

How the barcode will be printed.

There are several different types of barcode standardsfor different purposes - these are called symbologies.Each type of symbology (or barcode type) is astandard that defines the printed symbol and how adevice, such as a barcode scanner, reads and decodesthe printed symbol.


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Contd..

When multiple parties or companies are involved in the IDprocess, industry standards are usually established. Note

that the standard is not necessarily the same as the barcode

symbology. If an industry standard has been established for

the customer's use of bar-coding, then most likely there willnot be a choice in selecting the barcode symbology.

Barcode standards define how to use the barcode

symbology in a particular situation. For example, ISBN is a

standard for labeling books and periodicals that uses theEAN-13 symbology.


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Two types of Barcodes(examples):

Linear Barcodes 2D Barcodes

Code 128 Data Matrix

UPC Pdf 417


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Some Established Barcode Industry

Standards:

Established standard Common use Symbology

AIAG Automotive item

identification

Data Matrix

UPCA, EAN13 Items for saleworldwide

UPC/EAN

MIL-STD-130L US Department of

defense

Data Matrix

SSCC-18 Shipping cartons Code 128


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Benefits of Barcoding:

ACCURACY OF DATA INPUT (ERROR FREE)

AID EFFECTIVE MANAGEMENT OF RESOURCES AND INVENTORIES

LABOUR SAVINGS BY AVOIDING MANUAL SYSTEM

COST EFFICIENT

REAL TIME DATA COLLECTION

MEASUREMENT OF WORK IN PROGRESS THROUGHOUT THE

FACTORY

RAPID ACCESS TO TOTAL PRODUCTION COSTS

MORE ACCURATE DISPATCH


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Applications:

RETAIL APPLICATIONS Super markets

Counter-mounted Bar Code scanners Universal Product Code (UPC) Price and description information

WARE HOUSING

HEALTH CARE APPLICATIONS Drugs, devices, instruments Identification of expiry date

Blood banking Blood group Expiry date Donor traceability


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Campus Overview

907/A Uvarshad,

Gandhinagar

Highway, Ahmedabad

382422.

Ahmedabad Kolkata

Infinity Benchmark,

10th Floor, Plot G1,

Block EP & GP,

Sector V, Salt-Lake,

Kolkata 700091.

Mumbai

Goldline Business

Centre Linkway

Estate,Next to Chincholi Fire

Brigade, Malad (West),

Mumbai 400 064.


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Thank You

Working of barcode reader Presentation - Unitedworld School of Business

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