OUTPUT DEVICES Output devices translates information processed by the computer into a form you can understand. Can you guess which of these devices are OUTPUT devices?
OUTPUT DEVICES Output devices can be divided into two categories: SOFTCOPY output devices and HARDCOPY output devices. SOFTCOPY HARDCOPY Monitors (VDUs) Printers Projectors Speakers Video Graphics Card
SOFTCOPY vs HARDCOPY Softcopy output is information in intangible form i.e. It is displayed on a screen or in audio or voice form through speakers. Hardcopy output is tangible and refers to output which is printed.
SOFTCOPY OUTPUT DEVICES Monitors – these are also called Visual Display Units (VDUs). There are two types of monitors. These are Cathode Ray Tube (CRT) and Flat Panel Displays.
CRT MONITORS vs FLAT PANEL SCREENS Differences between CRT Monitors and Flat panel monitors. It is less expensive. It is more expensive. It takes up more desk space. Doesn’t take up much space. It uses more energy. Are more energy efficient. It is heavier and bulkier. Weigh’s much less. It emits harmful radiation. Doesn’t emit radiation. It is used only for PCs. Also used for laptops, PDAs, cellular phones.
SPEAKERS Normal music system speakers are used to output sound. They convert the sound from electronic form stored in the computer to what the user can understand.
HARDCOPY OUTPUT DEVICES Printers – Printers can be divided into two broad categories IMPACT and NON IMPACT printers. IMPACT printers produce their output when the printing mechanism strikes the paper to make a print. NON IMPACT printers produce their output without their printing mechanism making any impact with the paper.
IMPACT PRINTERS Two common impact printers are DOT MATRIX printers and LINE printers. Dot Matrix Printer Line Printer
DOT MATRIX PRINTERS Dot matrix printers contain a print head with up to 24 pins arranged in a rectangular pattern (matrix). These print one character at a time which are formed by specific patterns of dots struck by the pins. The print quality is not very good and they are slow.
LINE PRINTERS A Line printer is an impact printer which appears to print one line at a time.
NON IMPACT PRINTERS Four types of Non Impact printers are: LASER printers, INKJET printers, PLOTTERS and THERMAL printers. Laser Printer Inkjet Printer Thermal Printer Plotter
LASER PRINTERS Used in many large companies or institutions. They produce very high quality output at terrific speeds. They are also called PAGE printers because the appear to print an entire page at a time. Some can produce up more than 40 pages per minute. http://www.youtube.com/watch?v=KtXes1sgUb4This video gives you a good idea of how a laser printer produces output.
INKJET PRINTERS These printers produce their output by spraying small, electrically charged droplets of ink from nozzles, through holes, at a high speed, onto the paper. The quality of printing is high but not as high as laser printers. http://www.youtube.com/watch?v=N3e55hXt- LA&feature=relatedThis video gives you a good idea of how an inkjet printer produces output.
THERMAL PRINTERS These have a print head made up of pins arranged in a pattern (matrix). These pins are heated electrically and burn the characters onto heat-sensitive paper.
PLOTTERS A Plotter is a special printer designed to produce high quality graphics in vibrant colour on a large scale. They are especially useful for creating maps, billboards, banners, architectural drawings and charts.