Q.10. What is printer? Describe different types of printers.
Printer is a device that accepts text and graphic from a computer and transfers the information to paper.
Printer is an output device that transfers the information to paper-called hardcopy
TYPES OF PRINTERS ON THE BASIS OF TECHNOLOGY
In terms of the technology utilized. Printers tall into two basic types.
l. Impact Printers
2. Non Impact Primers
1. IMPACT PRINTERS
* Impact printers include all printers that work by striking an ink ribbon.
* They can produce carbon copies.
* Impact printers are much noisier than other printers.
TYPES OF IMPACT PRINTERS
1. Daisy Wheel Printer
They print one character at a time similar to at ball-head typewriter. This type of printer has a plastic or metal wheel on which the shape of each character is embossed electric motor spins the wheel and a. A hammer presses the wheel against the ribbon which in turn makes an ink stain in the shape of character on the paper. Daisy it heel printers produce better quality print but cannot print graphics.
2. Dot Matrix Printer
Dot Matrix printer are also character printer because they print one character at a time Dot matrix printers creates characters by striking pins against an ink ribbon. Each pin makes a dot and combinations of dots form characters and illustrations.
3. Line Printer
Line printer contains a chain of characters or pins an entire line at one time. Line printers are very first but produce low quality print; Drum printers and Chain printers are sub division line printers.
2. NON-IMPACT PRINTERS
Non impact printer use magnetic, electronic, thermal, chemical, optical, inkjet or laser technology to give output on paper. They cannot produce carbon copies, they are called quit printers.
Non-impact printers includes laser printers, inkjet printers etc.
TYPES OF IMPACT PRINTERS
1. Ink Jet Printer
Inkjet printers spray ink on sheet of paper. They produce high quality text and graphics.
2. Laser Printer
Laser printers use the same technology as photocopier machines. Laser printers produce high quality text and graphics.
3. LCD & LED Printer
Similar to a laser printer, but uses liquid crystals or light emitting diodes rather than a laser to produce an image on the drum.
4. Thermal Printer
An inexpensive printer that works h pushing heated pins against heat sensitive paper. Thermal printers are widely used in calculators and fax machines.
TYPES OF PRINTERS ON THE BASIS OF CHARACTERISTICS
Printers are also classified h three following characteristics:
1. Quality of print
The output produced b printers is said to be either better quality (as good as typewriter), near better quality, or draft quality) Only Daisy wheel, ink jet and laser printers produce better quality type. Some dot matrix printers claim better quality print, but you look closely, you can see the difference.
Measured in characters per second (cps) or pages per minute (ppm), the speed of printers varies widely. If you do much printing, the speed of the printer becomes important.
• Daisy wheel printers tend to be the slowest, printing about 30 cps.
• Line printers are fastest (up to 3,000 lines per minute)
• Dot matrix printers can print up to 500 cps.
• Laser printers range from about 4 to 20 text pages per minute. Generally, more expensive printers are much luster.
Some printers (daisy wheel and line printers) can print only text. Other printers can print both text and graphics.
Some printers, notably dot matrix printers are limited to one or a few fonts. In contrast, laser and ink-jet printers are capable of printing an almost unlimited variety of fonts.
• Color is important for users ho need to print pages for presentations or maps and other pages where color is part of the information.
• Color printers can also be set to print only in black- and white.
• Color printers are more expensive to operate since they use two ink cartridges (one color and one black ink) that need to he replaced after a certain number of pages.
Printer resolution (the sharpness of text and images on paper) is usually measured in dots per inch (dpi). Most inexpensive printers provide sufficient resolution for most purposes at 600 dpi.