The document discusses various input and output devices for computer graphics including keyboards, mice, trackballs, digitizers, scanners, printers, and plotters. It describes the basic functions of these devices such as using a keyboard to enter text, a mouse or trackball to control screen pointers, and printers and plotters to produce hard copy output. The document also provides comparisons of different types of printers and plotters such as dot matrix, inkjet, laser, drum, flatbed, and inkjet plotters in terms of their printing technologies and applications.
3. Keyboard
• It is composed of buttons used to create letters,numbers,and
symbols, and perform additional functions.
• There are 86-key laptop keyboard for Windows
There are two types of keys are:
• Function keys
• Cursor control keys
3
4. Mouse
• A pointing device that fits comfortably under the palm
of hand.
• The most widely used pointing device on desktop
computers.
• The mouse controls the movement of the pointer, also
called the mouse pointer, on the screen.
4
5. Trackball
• It is a pointing device. It is similar to a mouse. This is mainly used
notebook or laptop computer, instead of a mouse. This is a ball
which is half inserted, and by changing fingers on the ball, the
pointer can be moved.
5
6. Light Pen
• It is (similar to the pen) a pointing device which is used to select
displayed menu item or draw pictures on the monitor screen. It
consists of a photocell and an optical system placed in a small
tube. When its tip is moved over the monitor screen, and pen
button is pressed, its photocell sensing element detects the
location and sends the corresponding signals to the CPU.
6
8. Printer
• A printer is a hardware output device that is used to generate hard copy
print any document.
• A document can be of any type such as a text file, image, or the
of both. It accepts input command by users on a computer or on other
devices to print the documents.
There are two types of printers are:
• Impact Printer: It is press formed characters face against an inked ribbon
onto the paper. Examples are dot matrix, daisy wheel printers etc.
• Non Impact Printer: They use laser techniques, ink jet sprays, xerographic
processes, electrostatic methods and electrothermal methods to get
onto paper. It uses various techniques to combine three color pigments
(cyan,magneta and yellow) to produce a range of color patterns.
8
9. 9
Dot Matrix Printer
It is popular computer
printer that prints text
graphics on the paper by
using tiny dots to form
the desired shapes.
It uses an array of metal
pins known as printhead
to strike an printer ribbon
and produce a dots on
paper.
Daisy Wheel Printer
It can print only
and a symbols.
They are generally slow
with a printing speed of
about 10 to 75 characters
per second.
Ink Jet Printer
It is a computer
that produces hard copy
by spraying onto paper. It
can produce copy with a
resolution of at least 300
dots per inch(dpi).
COMPARISON BETWEEN IMPACT PRINTERS
10. 10
Laser device
A laser beam creates
charge distribution on
a rotating drum
coated with a
photoelectric material
such as selenium.
Toner is applied to
drum and then
transferred to paper.
Example: Laser printer
with a resolution of
360 dots per inch.
Ink-Jet
It produces output by
squirting ink in
horizontal rows across
a roll of paper
wrapped on a drum.
The electrically
charged ink stream is
defected by an
field to produce dot
matrix patterns.
Electrostatic
The devices places a
negative charge on
the paper, one
complete row at a
time along the length
of the paper. A paper
is exposed to a toner.
A toner is positively
charged and so is
attracted to the
negatively charged
areas, where it
to produce the
specified output.
Electrothermal
It uses heat in a dot
matrix print head to
output patterns on
heat sensitive paper.
COMPARISON BETWEEN NON IMPACT PRINTER
11. Plotter
• It is a type of printer that prints vector graphics.
• It is a piece of computer gear that converts computer commands into
line drawings.
• It draws a line with one or more automatic pens. Unlike a traditional printer,
a plotter uses a pen, marker, pencil, or other writing tools to draw multiple
rather than toner.
• It may also use vector graphics files or commands to draw continuous
to-point lines.
11
12. 12
Drum Plotter
It is a pen plotter that wraps
the paper around a drum
a pin feed attachment.
The drum rotates the paper
pens move across it and draw
the image.
It was the first output devices
used to print graphics and
large engineering drawings.
Flat-Bed Plotter
It is mechanical drafting
device used with CAD
programs for designers.
The paper remains stationary
on a flat surface while a pen
moves across it horizontally
and vertically.
It uses different colors pens to
create graphics.
Ink-Jet Plotter
It creates an image by
spraying small droplets of ink
onto paper.
It is popular choice for
advertising agencies and
graphics designers, inkjet
plotters are used generally
large outputs, such as
and billboards and large signs
often along roadsides.
COMPARISON BETWEEN DIFFERENT PLOTTERS
