The document provides an overview of various input devices, including keyboards, character readers, pointing devices, and scanning devices. It explains the functionality and applications of devices like magnetic-ink character readers, optical mark readers, smart cards, and different types of pointing devices, such as mice and touchscreens. Additionally, it discusses other input methods, including voice recognition systems and touch-tone devices.

1. Topic-7
Input Devices

2. Keyboard
• It is the most common of all input devices.
• Microcomputers offer enhanced keyboards for easy entry of numbers.
• This is accomplished with a smaller group of keys known as a numeric
keypad at the right of the keyboard.
• These keys generally consist of the digits, a decimal point, a negative sign and
an ENTER key.
• This type of keyboard is ideal for accounting operations which require a
large volume of numbers to be entered.

3. Keyboard
• A keyboard generally utilize integrated circuits to perform essential functions,
such as determining binary code, to send to the CPU corresponding to each
depressed key, switching between shifted and non-shifted keys, repeating a
key code etc.
• The keyboard arrangement provided as standard on most keyboards is the
QWERTY arrangement, named for the six letters beginning at the top left of
the key board.

4. Keyboard
• This arrangement was chosen intentionally to slow expert typists, since they
type too fast to cause the keys on mechanical type writer to jam.
• Slowing down the typist was accomplished by scattering the mostly used
keys, making frequently used combinations of letters slower to type.
• The QWERTY keyboard has been in used for almost a century.

5. Reading Devices
• A character reader is capable of accepting printed or typed characters from source
documents and converting these data into a computer-acceptable code.
• The basic types of character readers are:
Magnetic-ink reader
Optical mark reader
Optical character reader
Hand written character reader
Smart cards etc.

6. Magnetic-ink Character reader
• Magnetic Ink Character Reader (MICR) can read data prerecorded on checks and deposit slips with
a special ferrite-impregnated ink.
• Magnetic ink character recognition readers are the primary tool used for check sorting,
processing and validation. When scanning a document such as a check, MICR readers magnetize
the ink and detect the MICR characters. The reader head of the device reads the characters.
• The magnetized characters can be read and interpreted by MICR equipment.
• Human involvement is minimal thus the potential for errors is small
• It is fast, automatic and reliable.
• However some human involvement is still required to encode the cheque amount in MICR
characters thus, some room for errors does remain.

7. Optical mark reader
• Optical mark reader (OMR) optically reads marks on carefully printed forms.
• Optical mark forms are relatively expensive, as they must be printed with
exact tolerances.
• The most popular use of such devices is optical readers for scoring
examinations in educational institutions.

8. Optical character reader
• Optical character reader (OCR) devices can convert data from source
documents to a machine-recognizable form.
• Applications of optical scanning include billing, insurance premium notices,
invoices etc.
• An OCR can reliably read and interpret script or handwriting.
• OCR are limited with respect to hand written characters and can only read
handwritten digits and some symbols.

9. Hand written character reader
• Data recorded by hands have dropped substantially over the last decades,
however quite a bit of data are still recorded this way.
• As OCR technology advanced, designers felt that it would be possible to
convert handwritten data into computer-usable form in much the same way
that typewritten data are.
• Devices with this capability are the most sophisticated and versatile of
the OCR devices.

10. Smart cards
• A smart card is small in size and to use it, the card is inserted into a special card-
reading terminal and then password is entered.
• The cards have microchips that can keep permanent records. Which are updated
each time the card is used.
• The transaction data stored on the card can later be read into the computer to
update the user’s bank records.
• Now a days smart card are used to pay bills. But merchandise, make phone calls
etc.

11. Pointing Devices
Mouse
• A mouse is a hand-movable device that controls the position of the cursor
on a screen.
• It has a box with buttons on the top and a ball on the bottom.
• The box is placed on a flat surface (mouse mat) with the user’s hand over it.
• It has become most popular pointing device for graphic interfaces by
windows.
• With the mouse one can control the PC by pointing to images.

12. Pointing Devices
Light Pen
• The earliest pointing device is the light pen.
• This device is placed close to a screen or monitor and turned on.
• A photo sensor inside light pen detects the scanning beam sweeping back
and forth across the screen.
• Light pens are used to select items from a list or menu displayed on the
screen and to draw graphic displays on the screen.

13. Pointing Devices
Digitizer Pad
• Digitizer pad looks like a graph pad with a pointer.
• If functions like a light pen on a display screen except that the pad is mounted
horizontally.
• As the pointer is moved on the pad, the corresponding point on the screen is
illuminated.
• The digitizer pad is useful in converting graphic input, such as charts, graphs
and blueprints into patterns that can be stored by the computer.

14. Pointing Devices
Joystick and Trackball
• Joysticks are used with video games for user input.
• These devices may also be used to move the cursor around a screen to facilitate
input to a graphical display.
• A trackball is similar in operation to the joystick.
• It uses a billiard-sized ball to position the cursor.
• Several keyboard manufacturers have integrated them directly into their
keyboards.

15. Pointing Devices
Touchscreen
• Touchscreen detects the tough of a human finger.
• One popular technique used to detect the touch of a finger utilizes infrared
light beams.
• In this technique, infrared light beams shine horizontally and vertically on the
face of the screen.
• A pointing finger interrupts both horizontal and vertical beams, pointing its
exact location.

16. Scanning Devices
Scanners
• Scanners allow a PC to convert a drawing or photograph into code that a
graphics or desktop publishing program can use to display the image on the
screen, to reproduce the image with a printer.
• A scanner can also convert printed text into editable text with the help of
optical character recognition software.

17. Scanning Devices
Bar code Reader
• A bar code reader is a device for scanning or reading a bar code.
• Bar code is printed code that consists of parallel bars of different width and
spacing.
• The application most commonly observed is the coding on food and the goods
that is read at the checkout counter and translated into a line of print on the
bill showing price and cost.
• The information is also used to update stock record and provide sales statistics.

18. Scanning Devices
Digital Camera
• A digital camera uses light-sensitive electronic technique instead of film to
capture images.
• Instead of a photo album, one can store picture in PC’s hard drive or in a
writable CD-ROM.
• Digital photography is not new, although most digitalized photos make their
way to disk via conventional photography scanners.
• Digital cameras that eliminates scanners already exists.

19. Other Input Devices
Punched card
• It serves as an input medium to automated computational devices.
• It has undergone little or no change, and most users have phased out and
replaced it with the more efficient data entry media.
• Among the punched card devices still is use is the punch card reader.

20. Other Input Devices
Voice input device
• Voice input device or voice recognition system converts spoken words into
electrical signals by comparing the electrical patterns by a speaker’s voice with a set
of prerecorded patterns.
• If a matching pattern is found, the computer accepts this pattern as a part of its
standard “vocabulary”
• The biggest problem with this technology are limitations on the size of the
computer’s vocabulary, pronunciation differences among individuals and the
computer’s inability to accept continuous speech.

21. Other Input Devices
Touch-tone device
• It has wide spread use in many developed nations.
• Touch-tone devices can be used to send data to a computer.
• Touch-tone devices are also used to run credit card checks in retail stores.
• After appropriate keys are touched, the device sends data over a phone line
to a central computer, which then checks the data against files and report
credit information back to the store.

22. Thank You!