IT: Types and Functions of Output Devices
What are the types of printers?
-Character printers -Line printers -Page printers OR -Impact printers -Non-impact printers
What are the two types of thermal printers?(character printers)
-Direct Thermal printer -Thermal wax transfer printer
What are examples of output devices?
-Display screens -Speakers -Printers -Plotters -Audio card
What are the characteristics of dot matrix printers?(character printer)
-It is very noisy -It is relatively fast -The print obtained is usually poor -Characters are formed from a matrix of dots -They aren't good for printing shaded graphics or photographs
What are the characteristics of daisy wheel printers?(character printer)
-It's very noisy -Printing is slow -The text is generally crisp and clean *This printer is obsolete
What are the main types of non-impact printers?
-Laser printer -Inkjet printers -Thermal printers
What are the characteristics of drum, chain or band printers?(Line printers)
-They are fast(2500 lines/min) -They are used to print large volumes of information
What are some common resolutions?
-VGA(Video Graphics Array)=640 x 480 pixels -SVGA(super video graphics array)=800 x600 -XGA/XVGA(extended graphics array/ extended video graphics array)=1024 x 768 -SXGA(super extended graphics array)=1280 x 1024 pixels UXGA(ultra extended graphics array)=1600 x 1200 pixels
What are some types of impact printers?
-dot matrix -daisy wheel -drum, chain/band printers
What are the two types of display screens?
1)Cathode Ray Tubes(CRT) 2)Flat Panel displays
What are the two types of flat panel display screens?
1)Liquid Crystal Display(LCD) 2)Plasma Display
What ae the main types of plotters?
1)Pen plotters 2)Inkjet plotters 3)Electrostatic plotters
What are the two types of output?
1)Softcopy output 2)Hardcopy output
What are pixels?
A pixel is short for picture element and is the smallest unit on the display screen. They form images and text by many dots of coloured light. The number of pixels determines the resolution of the screen.
What is a video graphics card?
A video graphics card is also a video display adapter which determines the resolution, number of colours and speed with which images appear on the screen.
What is an audio card?
An audio card is used to process sound in the computer.
What is COM(Computer output on Microfilm/Microfiche)?
COM is a method used to store computer documents by reducing them in size to fit on very small photographic sheet of film and are used to store large volumes of data. Those sheets can be read using a special magnifying machine.
What are Cathode Ray Tubes?
Cathode Ray Tube screens look like a standard television set.
What are character printers?
Character printers print one character at a time similar to a typewriter, they are slow.
What is direct thermal printer?
Direct thermal printer uses heated pins to form the characters and these pins come into contact with special heat-sensitive paper to form darkened dots when the pins reach a specific temperature, thus shaping the characters. The pins burn the dots into specially coated paper. Exposure to sunlight and heat tends to darken the thermal paper and print quality is poor.
What are display screens?
Display screens are also called monitors or Visual Display Units(VDU) and are used to output still or moving pictures.
What are electrostatic plotters?
Electrostatic plotters work in the same way as laser printers.
What are Flat Panel displays?
Flat Panel display screens are used mainly with portable computers like laptops, in some desktop computers and the latest television sets.
What is hardcopy output?
Hardcopy output is permanent output which is tangible( you can hold it in your hands).
What is meant by human readable?
Human readable is if the output can be read by human beings.
What are impact printers?
Impact printers use a printing mechanism called a print head and they make their output by pressing the print head against a ribbon which then hits the paper.
What is an example of hardcopy output?
Information printed onto paper or film
What are Inkjet plotters?
Inkjet plotters work in the same way as inkjet printers by spraying ink onto the paper.
What are inkjet printers?(line printers)
Inkjet printers produce their output by spraying small droplets of ink at high speed into paper in a pattern. They can print in both black and white and colour and are used at home and small offices. The prink quality is good and they are cheaper than laser printers. They can produce both text and graphics.
What are laser printers?(page printers)
Laser printers use a process similar to a photocopying machine and are used in large companies/institutions and modern offices. A laser beam and dry powdered ink called toner produces a very fine dot matrix pattern and is transferred to the page and then fused onto it by heat and pressure. They can print black and white or colour and produce more than 40 pages/min. The print quality is very good, they produce both text and graphics and are very expensive.
What are line printers?
Line printers print a line at a time, multiple hummer-like keys forming a line of text hit the page at one time. They are used to print large volumes and print a limited number of characters but they don't print graphics.
What is meant by machine readable?
Machine readable is if the output cannot be understood by humans.
What is Microfilm/Microfiche?
Microfilm is a roll of film and microfiche is a rectangular sheet of film on which many frames/pages of information can be stored.
What are non-impact printers?
Non-impact printers are faster, quieter and produce better quality print than impact printers. The printing mechanism makes no contact with the paper.
What are output devices?
Output devices are equipment used to get information or any other response out of the computer.
What are page printers?
Page printers print a whole page at a time, they are faster and deal with very large volumes of printed output.
What are pen plotters?
Pen plotters use a mechanical arm/ rail that holds a pen which can be moved across the page.
What are plotters?
Plotters use different printing processes and are used to produce documents with high quality graphics in a variety of colours eg. maps, charts and they can print on large sheets of paper.
Hardcopy output devices
Printers
What is the resolution?
Resolution is the clearness or sharpness of an image on a screen. The more pixels there are on the screen, the greater the resolution.
What is softcopy output?
Softcopy output is temporary output which disappears when the computer is switched off since the screen or the speakers need the computer to work.
What are audio output devices?
Speakers, headphones and earphones are used to output sound and the quality of the sound depends on the type of system used, the size of the speakers and the computer's audio card.
What is an example of softcopy output?
The information displayed on a screen or in voice/audio form through speakers
What is thermal wax transfer printer?
Thermal wax transfer printer is where the pin head of this printer melts a wax-based ink from a transfer ribbon onto paper. This printer doesn't require special paper.
Where are thermal printers used?
They are used in portable calculators, fax machines and some ATMs(automated teller machines)