Printers have virtually replaced the typewriter in the modern office.
The simplest printers are designed for the home user, while the most complex are designed for production use, producing over 60 pages per minute and offering features like collating, stapling, and internal two-sided printing.
typically support colour; and are used (shared) by a group of users. Shared laser printers typically print over 50 pages a minute. typically do not support colour; are less expensive and are used by many single users. They typically can print 15 to 17 pages a minute. Shared laser printers Personal laser printers
The laser printer is considered a non-impact printer , and because it creates printouts one page at a time (rather than one line at a time)
It is also considered as a page printer.
Laser printers use very small dots, so they are able to provide excellent resolution.
They are also able to blend colours into practically any shade.
Like inkjet printers, laser printers use friction feed to move the paper through the printer. However, there is more than one set of rollers within the laser printer, to keep the page moving smoothly until it is ejected.
Laser printer are the quietest and fastest printers, but they are also the most expensive to purchase.
Laser printers usually have a motherboard much like that of a PC, complete the CPU, memory, BIOS (Basic input / output system), and ROM (read-only memory) modules containing printer language and fonts.
When upgrading a printer, check for any updates to the BIOS, additional memory requirements for new options, and firmware revisions.
To reduce maintenance cost, laser printers use disposable cartridges and other parts that need periodic replacement.
The primary consumable is toner, a very fine plastic powder bonded to iron particles. The printer cartridge also holds the toner cylinder, and often the photosensitive drum. The cartridge requires replacement when the level of toner is too low to produce a uniform, dark print.
The laser beam paints the image of the printed page on the drum. Before the laser is fired, the entire surface of the photosensitive drum and the paper are given an electrical charge carried by a pair of fine wires.
Inkjet printers use ink in cartridges, rather than ribbons, to create text or graphic printouts.
The ink cartridge in an inkjet printer contains a small pump, which forces ink out of the reservoir, through a nozzle, and onto the page.
Inkjet printers create printouts line by line, so they are considered line printers, but their print mechanisms do not make contact with the page, so they are considered non-impact printers.
Inkjet printers provide much better resolution than dot matrix printers and are capable of using coloured ink. Unlike dot matrix printers, inkjet can combine basic colours to produce a wide range of colours.
Inkjet printers are not nearly as loud as dot matrix printers and are much faster.
Depending on the manufacturer and model of the printer, ink cartridges come in various combinations, such as separate black and colour cartridges, colour and black in a single cartridge or even a cartridge for each ink colour. The cartridges of some inkjet printers include the print head itself.
Most inkjet printers have a tray that you load the paper into. Some printers dispense with the standard tray for a feeder instead. The feeder typically snaps open at an angle on the back of the printer, allowing you to place paper in it. Feeders generally do not hold as much paper as a traditional paper tray.
Used by manufacturers such as Canon and Hewlett Packard
this method is commonly referred to as bubble jet.
In a thermal inkjet printer, tiny resistors create heat, and this heat vaporizes ink to create a bubble. As the bubble expands, some of the ink is pushed out of a nozzle onto the paper. When the bubble "pops" (collapses), a vacuum is created. This pulls more ink into the print head from the cartridge. A typical bubble jet print head has 300 or 600 tiny nozzles, and all of them can fire a droplet simultaneously.
View of the nozzles on a thermal bubble inkjet print head
A crystal is located at the back of the ink reservoir of each nozzle. The crystal receives a tiny electric charge that causes it to vibrate. When the crystal vibrates inward, it forces a tiny amount of ink out of the nozzle. When it vibrates out, it pulls some more ink into the reservoir to replace the ink sprayed out.
The matrix printers are the “original” type of printer used with PCs; they have been around for a long time.
Dot matrix printers are so named because they use a matrix of pins to create dots on the paper.
Each pin is attached to a solenoid, which, when activated, force the pin toward the paper. As the print head (which contains the pins) moves across the page, different pins are forced forward to strike a printer ribbon against the paper.
Because of this action, dot matrix printers fall into the impact printer category. This process of the print head or pins physically striking the paper often makes loud sound. Furthermore, because the printouts are created line by line, dot matrix printers are also considered line printers .
Because of the print process they use, dot matrix printers do not provide very good resolution. That is, text and images usually appear grainy, and if you look closely at a dot matrix printout, you will be able to see each individual printed dot. Furthermore, dot matrix printers are limited in their ability to use colour.
In the Port Name box, type the path to the printer in the following format, where server is the name of the print server and printer is the name of the printer: erverprinter or you can also type any name (eg myPrinter ) to install new printer driver. Install Printer Software dialog box appears, select Printer Manufacturer and Printer model
Some input devices save users time by eliminating manual data entry. With these devices, users do not type, speak, or write into the computer. Instead, these devices capture data from a sources document, which is the original form of the data. Examples of sources documents include time cards, order forms, invoices, pay-checks, advertisements, brochures, photographs, inventory tags, or any other document that contains data be processed.
Devices that can capture data directly from a source document include optical scanners, optical readers, and magnetic strip. Scanners move across text and images. Scanning devices convert scanned text and images into a form that the system unit can process. There are three types of scanning devices: optical scanners, bar code readers, and character and mark recognition devices.
An optical scanner, also known simply as scanner, accepts documents consisting of text and / or images and converts them to machine readable form. These devices do not recognize individual letters or images. Rather, they recognize light, dark, and coloured areas that make up individual letters or images. Typically, scanned documents are saved in files that can be further processed, displayed, printed, or stored for later use.
Optical Scanners are powerful tools for a wide variety of end users including graphics and advertising professionals who scan images and combine them with text. Lawyers and students use portable scanners as a valuable research tool to record information.
You are probably familiar with bar code readers or scanners from grocery stores. These devices are either handheld wand readers or platform scanners. They contain photoelectric cells that scan or read bar codes, or the vertical zebra-striped marks printed on product containers.
It is used by banks to automatically read those unusual numbers on the bottom of checks and deposit slips. A special-purpose machine known as a read/ sorter reads these numbers and provides input that allows bank to efficiently maintain customer account balances.
It uses special pre-printed characters that can be read by a light source and changed into machine-readable code. These are used in department stores to read retail price tags by reflecting light on the printed characters.
It is also called marks sensing. An OMR device senses the presence or absence of a mark, such as a pencil mark. OMR is often used to score multiple –choice tests such as the Collage Board’s Scholastic Aptitude Test (SAT) and the Graduate Record Examination (GRE).