A printer is categorised according to whether or not the image produced is formed by physical contact of the print mechanism with the paper. Impact printers have contact; non-impact printers do not.
To suit the needs of many different users, different types of printers and plotters are available that have slightly different characteristics and capabilities-cost, quality, and speed.
Laser Printer
Laser printer technology results in much higher printing speeds and quieter operation. The process resembles the operation of a photocopy machine. A laser beam is directed across the surface of a light' sensitive drum and fired as needed to record an image in the form of a pattern of tiny dots. The image is then transferred to the paper-a page at a time-in the same fashion as a copy machine transfers images, using a special toner. Laser printers can produce documents at speeds of 4 to 20 pages per minute (ppm)
Impact Printers
An impact printer makes contact with the paper. It usually forms the print image by pressing an inked ribbon against the paper with a hammer-like mechanism. One type of impact printer, called a dot-matrix printer, is made of separate pin-like hammers that strike the ribbon against the paper in computer-determined patterns of dots
Non-impact Printers
Most printers in use today are non-impact printers. These printers do not strike characters against ribbon or paper when they print. The main categories of non-impact printers are ink-jet printers and laser printers. These printers generate much less noise than impact printers.
Inkjet Printer
The ink-jet printer has a print head that sprays ink through a small hole onto a piece of paper. These printers are much quieter than the dot-matrix printer. They store ink in cartridges, that are easily replaced when they run out. Ink jet printers and Bubble Jet printers work the same way.
Dot-matrix printer
A number of thin print wires act as hammers squeeze ink out of the ribbon onto the paper.
These print wires are moved by electromagnet.
It used continuous sheet type and pre printed sheet type
Used banks, supper market, office, and many company
This printers gives only black and white print
Thermal Printer
It uses the medium of heat to print
Heat is product by electricity. Every time electricity passed printer had different heat. It used for print.
It requires special paper to print, portable and can run on battery.
Other characteristics that differentiate printers include:
Memory: Many printers also have their own memory since a computer can send data faster than a printer can access and print it. This data gets sent to the printer's spooler, or buffer, that holds the data, and releases it at a speed that the printer can handle. Printer memory is usually can be 1Mb to 4Mb.
Speed: The speed of the printer determines how quickly it can print the pages that you have selected. The speed is measured in characters per second (cps) and also pages per minute (ppm). A higher speed will result in faster output.
Resolution: Just like a monitor, the printer also comes in different resolutions. The resolution of a printer determines the quality of the image the printer can reproduce, and it is measured in dots per inch (dpi). A higher resolution results in sharper images. Printing graphics requires at least a 600 dpi printer
No comments:
Post a Comment