barcode reader(scanner)

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What is barcode?

What is barcode reader?

Brief history

Working

Types of barcode reader

and description of each type

Interfacing

Barcode types and use

Benefits,application,advantage and disadvantage

Conclusion

What is Barcode??• Barcodes are simply a set of symbols used to represent

alpha-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.

What is Barcode Reader??• 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.

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 on

grocery 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.

Working

• A bar code consists of a series of parallel, adjacent bars

and 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 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 electronic circuit.

There are five basic types of barcode readers..

- pen (wands) type reader

- slot scanners

- charge-couple device (CCD) scanners

- image scanner /camera based reader

- laser scanners

Types of Barcode Reader

Pen type readers and Laser Scanners

• Pen type readers consist of a light source and a photo diode

that are 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 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 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.

A slot scanner remains stationary and the item with the bar code on it is pulled by hand through the slot. Slot scanners are typically used to scan barcodes on identification cards.

Slot Scanner

Charge-Couple Device (CCD) Readers

A CCD scanner has a better

read-range than the pen wand and is often used in retail sales. Typically, a CCD scanner has a ‘gun’ type interface and has to be held no more than one inch from the bar code. Each time the bar code is scabbed, several readings are taken to reduce the possibility of errors.

A disadvantage of the CCD scanner is that it cannot read a bar code that is wider than its input face.

Camera based ReadersImg Scanner

• The newest type of bar code reader

currently available are camera-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.

• It can read a bar code from about 3 to 9 inches away and generally costs less than a laser scanner.

A laser scanner, either hand-held

or stationary, does not have to be close to the bar code in order to do its job.

It uses a system of mirror and lenses to allow the scanner to read the bar code regardless of orientation, and can easily read a bar code up to 24 inches away.

To reduce the possibility of error, a laser scanning may perform up to 500 scans per second. Specialized long-range laser scanners are capable of reading a bar code to 30 feet away.

Laser Scanner

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.

Interfacing a Barcode

reader to a PC

Why use Barcodes??

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

• Whenever there is a need to accurately identify or track something, bar-coding should be used. For example, in a data entry work environment, workers may be required to enter an enormous amount of data into a customer database system.

• Instead of manually typing a customer identification number into a database, if the information is contained in a barcode, a data entry operator may scan it in. This would increase automation and reduce human error.

Barcode types and use

The type of barcode to use for a particular situation

depends upon:

The use.

The data encoded in the barcode.

How the barcode will be printed.

There are several different types of barcode standards

for different purposes - these are called symbologies.

Each type of symbology (or barcode type) is a

standard that defines the printed symbol and how a

device, such as a barcode scanner, reads and decodes

the printed symbol.

• When multiple parties or companies are involved in the ID

process, 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

will not 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 the

EAN-13 symbology.

Two types of

Barcodes(examples)

Some Established Barcode

Industry Standards:

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

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

There are five basic advantages of barcode readers…

- Speed

- Accuracy

- Data Integrity

- Ease of Implementation

- Cost Effectiveness

Advantages of Barcode Reader

- System failure may cost more delays

- Scratched or crumpled barcodes may cause problems

- Data must be coded in the barcode

- In laser scanning, durability and cost are two disadvantages.

Disadvantages of Barcode Reader

Positive Impact On Daily Life.

Have Lots Of Advantages With Minor Bottlenecks.

It Has Its Versatile Uses & It’s User Friendly.

Laser Emission Near Or On Human Body Is Very Harmful.