this is about barcode reader types

2.  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

3. 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.

4. 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.

5. 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.

6. 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.

7.  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

8. 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.

9. • 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.

10.  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

11. 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.

12. Camera based Readers
Img 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.

13.  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

14. 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.

15. Interfacing a Barcode
reader to a PC

16. 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.

17. 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.

18. • 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.

19. Two types of
Barcodes(examples)

20. Some Established Barcode
Industry Standards:

21. 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

22. 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

23.  There are five basic advantages of barcode readers…
- Speed
- Accuracy
- Data Integrity
- Ease of Implementation
- Cost Effectiveness
Advantages of Barcode Reader

24. - 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

25.  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.