The Computer and its Components.
This article will cover Input devices:
Compiled by “Md.
Farrukh Asif”
There are 4
main computer components that are given below:
Previous: Input Devices Next: OutputDevices
·
Input Units
·
Output Units
·
Memory Units
·
Central Processing Unit
Q. What is Input Device?
Explain each of them briefly.
An input
device is any hardware component that allows a user to enter data,
commands, and instructions into a computer or other electronic systems. These
devices are essential for interacting with digital systems and can range from
simple to complex, depending on their purpose and design.
1.
Keyboard
Definition: A keyboard is an input device
consisting of a set of keys used to input data into a computer. It typically
includes alphabetic characters, numbers, symbols, and function keys.
Functionality:
·
Keyboards
allow users to type text, execute commands, and interact with software
applications.
·
They
often include special keys for specific functions like volume control, screen
brightness, and launching specific programs.
2.
Mouse
Definition: A mouse is a pointing device that detects
two-dimensional motion relative to a surface. It usually consists of buttons
and a scroll wheel.
Functionality:
·
The
mouse controls the movement of a cursor on the screen, enabling users to point,
click, and drag objects.
·
It
allows for interaction with graphical user interfaces (GUIs), such as opening
files, selecting text, and navigating websites.
3.
Microphone
Definition: A microphone is an input device that
captures audio signals from the environment and converts them into electrical
signals for processing by a computer.
Functionality:
·
Microphones
are used for voice recording, video conferencing, voice recognition, and other
audio applications.
·
They
can be built into devices like laptops and smartphones or can be external and
connected via ports like USB or audio jacks.
Click Me to Explore
Detailed description of the Computer and its Components.
(Input Units)
A Complete and Detailed Definition with examples of Output
Devices (New Tech based)
The Central Processing Unit (CPU) Latest Enquiries
Memory Unit (I/O) Devices by Farrukh
The Basic Terminologies of Computer by Md. Farrukh Asif
Generation of Computer by Md. Farrukh Asif
The Evolution of Computer Languages(Part-I) by Md. Farrukh
Asif
The Evolution of Computer Languages(Part-II) by Md. Farrukh
Asif
Computer Network Topologies
By Md. Farrukh Asif
Communication Protocols
by “Md Farrukh Asif”
Basic Computer's Features and Use by Md. Farrukh Asif
Operating System and its Functionality: by Md. Farrukh Asif
Batch OS and Time Sharing OS by Md. Farrukh Asif
Real-Time Operating Systems (RTOS): Explained Simply
The Wider
Use of Microkernel and its Components in OS
Fundamentals of Computer MCQs with Answers
4.
Scanner
Definition: A scanner is an input device that
captures images from physical documents and converts them into digital formats.
Functionality:
·
Scanners
are used to digitize documents, photographs, and other printed media, making it
possible to store, edit, and share them electronically.
·
They
work by illuminating the document and capturing the reflected light with a
sensor.
5.
Camera
Definition: A camera is an input device that
captures still images or video. It can be built into devices or used as an
external peripheral.
Functionality:
·
Cameras
are used for photography, video recording, video conferencing, and facial
recognition.
·
They
can capture high-resolution images and videos, which can be stored, edited, and
shared digitally.
6.
Touchscreen
Definition: A touchscreen is a display that also
serves as an input device, allowing users to interact directly with what is
displayed by touching the screen.
Functionality:
·
Touchscreens
detect touch inputs, such as finger taps, swipes, and gestures, to navigate and
control applications.
·
They
are commonly used in smartphones, tablets, laptops, ATMs, and self-service
kiosks.
---------------------------------------------
The
operations of computer components are given below:
1)
Inputting: It is the process of entering raw data, instructions, and
information into the computer. It is performed with the help of input devices.
2)
Outputting: It is the process of presenting the processed data through
output devices like monitors, printers, and speakers.
3)
Storing: The computer has primary memory and secondary storage to store
data and instructions. It stores the data before sending it to the CPU for
processing and also stores the processed data before displaying it as output.
4)
Controlling: This operation is performed by the control unit that is part
of the CPU. The control unit ensures that all basic operations are executed in the
right manner and sequence.
5)
Processing: It is the process of converting the raw data into useful
information. This process is performed by the CPU of the computer. It takes the
raw data from storage, processes it, and then sends back the processed data to
storage.
·
Input Units
Input device
enables the user to send data, information, or control signals to a computer.
The Central Processing Unit (CPU) of a computer receives the input and
processes it to produce the output.
Some of
the popular input units are:
1. Keyboard
2. Mouse
3. Scanner
4. Joystick
5. Trackball
6. Light Pen
7. Digitizer
8. Microphone
9. Magnetic Ink Character Recognition
(MICR)
10. Optical Character Reader (OCR)
11. Digital Camera
12. Paddle
13. Steering Wheel
14. Gesture recognition devices
15. Light Gun
16. TouchPad
17. Remote
18. Touch screen
19. VR
20. Webcam
21. Biometric Devices
1.
Keyboard:
Keyboard
keys are arranged in 6 groups such as:
1.
Alphanumeric keys: - The alphanumeric keys are the collection of alphabets
A-Z, numerals from 0-9, and punctuation marks that are arranged the same way on
almost every keyboard.
2. Numeric
keys: - It is usually located on the right side of the keyboard and appears like a
non-scientific calculator with ten digits (0-9) and arithmetic operators.
3. Function
keys: - The Function keys numbered from F1 to F12 are usually arranged in
a first row at the top of the keyboard. Each function key performs a different function
depending upon the current application being run by the user.
4. Cursor
movement keys: - These keys allow the user to change the position of the
cursor on the screen. Cursor movement keys move the cursor up, down, left, and right.
5. Special
purpose keys: - These keys perform special functions i.e. insert, delete,
print screen.
6. Modifier
keys: - These keys are used in conjunction with other keys. Modifier keys
include keys such as Alt (Alternate), Shift, and Ctrl (Control).
The keyboard
is a basic & pure input device that has a set of 101 keys and is used to
enter data into a computer or any other electronic device by pressing keys. It
has different sets of keys for letters, numbers, characters, and functions.
Keyboards are connected to a computer through a USB/COM port or a Bluetooth
device for wireless communication.
Types of
keyboards: There
can be different types of keyboards based on the region and language used. Some
of the common types of keyboards are as follows:
(i) QWERTY
Keyboard, (ii) AZERTY Keyboard, (iii) DVORAK Keyboard.
2. Mouse
A mouse is a
pointing device that controls the position of the cursor on a computer screen
without using the keyboard. It is called a pointing device because it is used to
point and select options on the screen. There are two or more depression switches on
the top of the mouse.
1)
Mechanical Mouse
It has a rubber or metal ball on its underside that can roll in
all directions. Mechanical sensors within the mouse detect the direction the ball
is rolling and move the screen pointer accordingly.
2)
Optomechanical Mouse
It is the same as a mechanical mouse but it uses an optical sensor
to detect the motion of the ball.
3) Optical Mouse
It uses a laser to detect the mouse’s movement. It responds
more quickly and precisely than mechanical and Optomechanical mice but is
more expensive.
Three simple
techniques to use the mouse: -
1) Clicking:
- To click on something with the mouse means, to move the pointer to the
item on the screen and to press and release the mouse button once.
2) Double
clicking: - To double click on an item means, to move the pointer to the item
on the screen and to press and release the mouse button twice in quick
succession.
3. Scanner
“A scanner is an input device which translates paper
documents into an electronic format, which can be stored in a computer.”
Input
documents may be typed text, pictures, graphics or handwritten material.
Scanning helps preserve paper documents in electronic format.
Or
A scanner is
an input device that is capable of capturing images, text, and handwritten
documents and storing it in the computer system. The scanner captures data and converts
it into a bit pattern for processing.
Characteristics
of Scanner
1. Human
efforts required for manual entry of data is eliminated by a scanner.
2. The
reduction in human intervention improves data accuracy.
3. The scanner requires high-quality input documents.
4. Most
of these devices are not economically feasible.
Types of
scanner
Scanner comes in various shapes and sizes following are their categories:-
1. Flatbed scanner
2. Sheet-fed
Scanners
3. Hand-held
scanner
4. Drum
Scanners
Example of
Scanners based on technology
Examples of
scanners is an optical scanners and Magnetic ink character readers.
1. Optical
Scanner:
The optical scanner uses light sources and light sensors to read
information recorded on paper. Commonly used optical scanners include-
a) Optical
Mark Reader (OMR)
b) Optical
Character Reader (OCR)
c) Optical
Barcode Reader (OBR)
Optical Mark Recognition is the process of gathering data with an optical scanner (Optical mark reader) by measuring the reflectivity of light at predetermined positions on a surface. An optical mark reader is commonly used to check special examination sheets.
How it
works?
The sheet may contain a square or bubble that is marked by pen/pencil.
The actual technique used for OMR devices for the recognition of marks involves
focusing a light source on the page. The reflected light is detected by OMR and
corresponding signals are sent to a processor. The change in light detects the
presence of a mark.
Advantages
1) Large
volumes of data can be collected quickly and easily without the need for
specially trained staff.
2) Only one
computer is needed to collect and process data.
Disadvantages
1) OMR
readers are relatively slow as compared to other optical scanners.
2) Only
suitable for multiple choice questions not suitable for text input.
3) It is
very expensive.
b) This is
described in section no 10.
c) OBR:
It is a photoelectric device that scans a set of vertical bars of different widths by means of reflected light. These vertical lines are called Bar codes that are used to represent alphanumeric data by varying the width and combination of adjacent vertical lines. Bar code reading is done by a scanner connected to a computer.
Bar code
structure
These bars
are detected at ten digits. The first five digits identify the supplier or
manufacturer of the item. The second five identify individual products.
Advantages of
Barcode reader
Accuracy,
Speed, Cost-effective, Ease of implementation (Can be easily operated)
It is also a
pointing device.. It consists of a lever that moves in all directions and
controls the movement of the pointer. Due spherical ball at its base, when the
lever steers the cursor moves in the respective direction. Potentiometers are
used to sense the movements.
E.g. It
is commonly used with computer games, flight simulators, and for controlling
robots.
5. Trackball
Trackball is
most commonly used in a notebook or laptop instead of a mouse.
Advantages
of Trackball: -
1. Trackball
is stationary.
2. Require
Less Space.
3. Compact
size.
4. Most
suitable for portable computers.
5. It
can be placed on any type of surface.
6.
Light Pen:
Light is a pointing
device that is used to select a displayed menu item or draw pictures on the
monitor screen. It is connected by a cable to the display device. The light pen
consists of a light-sensing element (photodiode) at the tip of the pen and a cable
through which the signal is transmitted. When the screen is touched with the tip
of a pen, the pen gets activated light spots are sensed and a signal is sent to the
system indicating the position.
E.g. Used
for corrections in architectural designs.
7.
Digitizer:
Digitizer is a
computer input device that has a flat surface and usually comes with a stylus.
It enables the user to draw images and graphics using the stylus as we draw on
paper with a pencil. The images or graphics drawn on the digitizer appear on
the computer monitor or display screen. The software converts the touch inputs
into lines and can also convert handwritten text to typewritten words.
8.
Microphone:
It is of
three types:-
i) Dynamic:
ii)
Condenser:
iii) Ribbon:
9. Magnetic Ink Character Recognition (MICR):
E.g. MICR is
primarily by the banking industry to facilitate the processing of cheques.
How it works
MICR scan
document is written with magnetic ink which contains iron oxide particles in it.
When a MICR document needs to be read, it passes through a machine, which
magnetizes the ink and then translates the magnetic information into
characters.
There are
two major MICR fonts in use: E-13B and CMC-7
Advantages
1. It reads
the character quite speedily and accurately.
2. MICR can
read data even if it's smudged crumbled or dirty.
3. It is
hard to reproduce the ink, hence hard to forge cheques.
Disadvantages
1. A special type of ink is used.
2. It cannot
be used for general-purpose data processing
3. It can
recognize a few types of font type.
4. The
readers and printers are relatively expensive.
10. Optical Character Reader (OCR):
It is used to recognize alphanumeric characters printed or typewritten on paper. The scanner detects the light reflected from the paper. The change in the reflected light is converted to binary data which is sent to a processor.
OCR can
recognize text written in two font formats specified by ANSI (American National
Standard Institute) which are OCR-A (American standard) and OCR-B
(European standard).
Application
of OCR
These
devices are used in banks, insurance companies, airlines, and some retail
outlets.
Advantages
1) It
reduces manual keystroke operation.
2) It can
also read the handwritten characters.
Disadvantages
1) Poorly
handwritten documents cannot be easily read by OCR
It is a
digital device as that captures images and records videos digitally and then
stores them on a memory card. It is provided with an image sensor chip to
capture images, as opposed to film used by traditional cameras. Besides this, a
camera that is connected to your computer can also be called a digital camera.
12.
Paddle:
13.
Steering Wheel:
It is used as an
input device in racing video games such as car racing games or in driving
programs as virtual simulators to steer a vehicle. It works like the real
steering wheel by allowing you to take a right or left turn. A steering wheel
may be provided with acceleration and brake pedal devices and a mechanism for
shifting gears. Thus, it makes racing games more adventurous and entertaining.
14. Gesture recognition devices:
15.
Light Gun:
As the name suggests,
it is a pointing input device that is designed to point at and shoot the
targets on the screen in a video game, or arcade, etc. The light gun was used
for the first time on the MIT Whirlwind computer. When the gun is
pointed at the target on the screen and the trigger is pulled, the screen goes
blank for a fraction of a second. During this moment, the photodiode, which is
present in the barrel, determines where the gun is pointed. For example,
shooting ducks in a duck hunt game.
16.
TouchPad:
It is usually found
in laptops as a substitute for the mouse. It allows you to move or control the
cursor on the screen using your finger. Just like a mouse, it also has two
buttons for right and left click. Using the touchpad, you can perform all the
tasks that you do with a mouse, such as selecting an object on the screen,
copying, pasting, deleting, opening a file or folder, and more.
17. Remote:
18. Touch screen:
It is the display screen of a device such as a smartphone, tablet, etc., that allows users to interact or provide inputs to the device by using their fingers.
19.
VR:
VR stands for virtual
reality. It is an artificial or virtual environment that is generated by
computers. A person can interact with virtual objects of this artificial
environment using some input devices such as headsets, gloves, headphones, etc.
For example, he or she can find himself or herself walking on a beach, watching
a football match, walking in the sky, etc., without actually doing all this.
20.
Webcam:
21. Biometric Devices:
Face Scanner
is designed to
identify a person by scanning his or her face. It takes the face measurements
of a person. For example, the distance between the eyes, nose, mouth, etc.,
accordingly, it confirms the identity of a person. Besides this, it is smart enough
to differentiate between a person's picture and the real person.
The hand of
a person can also be used to verify his or her identity as every person has a
unique pattern of veins in the palm, just like fingerprints. This device takes
advantage of this feature; it identifies a person by scanning the palm of his
hand. It uses infrared light to scan veins' patterns and the blood flowing in them.
Palm is even more unique than fingerprints.
It scans the
fingerprints to identify people or for biometric authentication. This device is
developed, keeping in mind the fact that no two persons in the world can have
the same fingerprints. It is widely used in companies as a fingerprint
attendance system to mark the attendance of employees.
This type of scanner captures the pattern of valleys and ridges found on a
finger and stores it in the memory or database. When you press your finger on
the given space, it verifies the identity by using its pattern-matching
software.
It scans the
retina or iris of a person's eye to confirm the identity. This device is more
secure than others as it is next to impossible to copy the retina or iris. It
works by mapping the retina's blood vessel patterns of the eye. The blood
vessels of the retina absorb light more easily as well as can be identified with
appropriate lighting.
In this
scan, a beam of low-energy infrared light falls on the retina through the
scanner's eyepiece. Then, the software captures the network of blood vessels in
the retina and uses it to verify a person's identity.
v) Voice
Scanner:
8. Speech
recognition system
These
devices recognize the voice and translate it into the text using a speech recognition system. Speech recognition software is loaded into the
machine which gathers sound waves removes unwanted noise and compares the
incoming signal against a pattern stored in memory. If the sound is similar or
almost similar then the voice is translated into text otherwise it is ignored.
The speech recognition system is equipped with the following components:
a) Computer
system with sound card
b) Speech
Recognition software
c)
Microphone
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Devices
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