Input devices are used by the computer user to input data to the computer. These devices take instructions as input from a user and further transfer to the CPU for processing.
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Keyboard |
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Keyboard –
This is the standard input device attached to all computers. The layout of the keyboard is just like the traditional typewriter of the type QWERTY. It also
contains some extra command keys and function keys. It contains a total of 101
to 104 keys
The keys layout on the keyboard as follow:-
Alphanumeric Keys
Numeric keys
Functional keys
Arrow keys
Special keys
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Mouse |
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Mouse –
A mouse is a pointing device that functions by detecting two- dimensional
motion relative to its supporting surface. Physically, a mouse consists of an
object held under one of the user's hands, with one or more buttons. The mouse's motion
typically translates into the motion of a pointer on a display, which allows
for fine control of a graphical user interface
Clicking, Double click, and Drag
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Trackball |
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Trackball
– The trackball is a variant to the mouse that is used at places where there is no
space to move around the mouse. Before the invention of touchpads, the trackballs were used with computer-controlled machines and in special applications
like CAD and graphic designing.
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Joy Stick |
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Joystick – It
is also a paddle. It is also a pointing device. It consists of a small,
vertical lever mounted on a base that is used to steer the screen cursor around.
Some joysticks are mounted on a base that is used to steer the screen cursor around. The joystick can be moved left or right, forward or backward, springs
are often used to return the joystick to its home center position.
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Light pen |
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Light Pen- A light pen is a pointing device used especially for graphic works. These were
developed early in the history of interactive computer graphics. It detects
light pulses, rather than emitting light as its name implies.
Light
pens are sensitive to the short burst of light emitted from the phosphor
coating at the instant the electron beam strikes a particular point.
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Touch Screen |
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Touch Screen
– A touch screen is an intuitive computer input device that works by simply
touching the display screen, either by a finger or with a stylus, rather than
typing on a keyboard or pointing with a mouse.
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Touchpad |
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Touchpad- The touchpad is also one of the most popular input devices used in laptops. They
are used as a substitute for the mouse. To use moves finger on it and the cursor on
the screen moves correspondingly. The touchpads work like touch screens to
detect the position of the finger. They are specifically designed to feel the
finger, don't use a pencil or pen. Dragging the finger on a touchpad will move
the cursor.
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Digital Camara |
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Digital Camera-
A digital camera can be used to take pictures. It can be hooked up to a
computer to transfer the pictures from the camera to the computer. Some digital
cameras hold some internal memory for storage.
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MICR |
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OCR
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Scanner- The scanner is an input device that uses the paper document as an input. The input data to be scanned maybe a picture or text. The scanner can be categories as
A. Hand-Held Scanner B. Flatbed Scanner
Optical Character Recognition (OCR)
- OCR, is the mechanical or electronic translation of
scanned images of handwritten, typewritten or printed text into machine-encoded
text.
Magnetic Ink Character Recognition
(MICR)- This is widely used by banks to process large
volumes of Cheques are put inside the MICR.
Optical
Mark Reader (OMR)- These OMR sheets are directly fed to a computer for grading or evaluation. OMR answer sheets mostly used in objective type question answers.
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