Touch Screen is a type of display screen that has a touch-sensitive transparent panel covering the screen so that it can recognize the location of a touch on its surface.
A scanner uses special light sensors to capture (or photograph) an image printed on paper and translate the information into a form the computer can use. To edit text read by an optical scanner, you need an optical character recognition (OCR) system to translate the image into ASCII characters.
A microphone converts sound waves into electrical signals that can be understood by your computer’s sound card. The sound card converts the electrical signals into digital data that your computer can process.
Output devices are peripheral devices that output information that has been held or generated within a computer.
Week6 input, output and storage devices
Keyboard, mouse, scanners,
tablets, digital cameras,
touch screens, and joysticks.
Today, standard keyboards have 104 or
105 keys. An electronic circuit inside the
keyboard transmits the code of a pressed
key to the CPU.
QWERTY is the most used modern-day
keyboard layout on English-language
computers. It takes its name from the first six
letters at the upper left of the keyboard.
Touch Screen is a type of display screen
that has a touch-sensitive transparent panel
covering the screen so that it can recognize
the location of a touch on its surface.
A light pen is a form of
a light-sensitive wand
used in conjunction
with a computer’s
monitor. It allows the
user to point to
displayed objects or
draw on the screen in
a similar way to a
touch screen but with
Graphics Tablet (Pen Tablet)
A tablet is an alternate type of input device
that can be used in place of a pointing
device. It enables you to enter drawings
and sketches into a computer. The tablet
consists of two parts, a flat surface for
drawing and a pen or stylus that is
programmed to work with the tablet.
Concept Tablet and Concept
Concept tablets and keyboards are
widely used for special purpose
computers when fast input is needed.
They are ideally suited for selecting from a
limited range of choices, such as taking
orders in a fast food restaurant.
A webcam is essentially a small camera that is connected
to a computer, either directly or wirelessly, and gathers a
series of images that are viewed in real time on the
computer screen or over a network, especially over the
There are two main types of
Flat panel monitors and cathode
ray tube (CRT) monitors.
A flat panel monitor uses a liquid
crystal display (LCD) instead of a
cathode ray tube to display
data. LCD monitors occupy less
space, consume less energy, and
are much lighter than CRT
monitors. Many monitor
companies have already
stopped producing CRT monitors.
A monitor connects to either a VGA (video
graphics array) or DVI (digital visual interface)
port on a video card. Both devices should
support the same type of connection.
Depending on the printing technologies, printers
are divided into three main categories: impact,
ink-jet, and laser printers.
Ink-jets (bubble-jets) printers: Ink-jet printers use
tiny jets to spray ink onto the paper.
Laser Printers: Laser printers produce high print
quality at high speed. They are called laser
printers because they use a laser beam to
produce an image on a drum.
Dot matrix printers push a row of pins through an
ink ribbon onto the paper. Dot matrix printers are
used for cheaper, low quality Printing.
A dot-matrix printer
A laser printer An Ink-Jet Printer
A plotter is an output
device similar to a
printer, but for larger
images. Plotters use
either pens or
and special chemicals
to print an image.
A storage device is a hardware device designed to
store and retrieve information.
Types of storage devices
There are two types of storage devices:
temporary storage devices and permanent
RAM, CPU caches, and CPU registers are
temporary storage devices.
Permanent storage devices hold information until
it is deleted or overwritten. Depending on the
technology, secondary storage devices can be
divided into three categories: magnetic, optical,
and flash storage.
Hard Disk Drive (HDD)
A hard disk drive (HDD), commonly referred
to as a hard drive, hard disk, or fixed disk
drive, is a device that stores digitally
encoded data on rapidly rotating platters
with magnetic surfaces. Hard disks are the
main large data storage area inside your
computer. Hard disks are used to store your
programs and data. They are much faster
than most other types of storage device
and can also hold much more data.
When a hard disk is manufactured, the
platters are empty, so your computer
cannot read them. The process of creating
the tracks and sectors on the platters and
preparing the disk for use is called
Solid-State Drive (SSD)
A solid-state drive is a
storage device that
memory to store
data. In contrast with
drives contain no
moving parts: no
spinning platters, no
moving heads. Data
are split into word-length
stored in memory.
Solid-state drives may be preferred over traditional
disk drives for a number of reasons:
The first advantage is the speed of operation.
The second advantage is that breakdown is less
likely. Because there are no moving parts, less
can go wrong mechanically and dropping the
drive is less likely to cause damage to the data.
Floppy Diskette (FDD)
Floppy disks are also called diskettes. They
are very slow compared to hard disks or
CD-ROMs and hold a smaller amount of
data (1.44 megabytes).
Floppy disks are also quite fragile. Floppy
diskettes are not used any more and
modern computers do not come with
floppy disk drives.
Computers can read and write data on special
cartridges of magnetic tape. A magnetic tape
cartridge looks like a music cassette.
A CD ROM (compact disc-read-
only memory) is a
type of optical disk
capable of storing large
amounts of data up to 1
GB, although the most
common size is 700 MB.
Its main uses are video
and data storage. DVDs
are of the same
dimensions as compact
discs (CDs) but are
capable of storing much
more data (about 4.7 or
8.5 GB of data on one
side, or 17 GB on a disk
with two sides)
The Blu-ray disk is a high
density optical storage
The format offers more
than five times the storage
capacity of traditional
DVDs and can hold up to
25GB on a single-layer disc
and 50GB on a dual-layer
disc. Recent development
by Pioneer has pushed the
storage capacity to 500 GB
on a single disc by using 20