Printers

Printers  Back Printers produce paper copies of electronic files. Scanners allow users to convert paper documents into electronic files. Many government regulations require physical records; therefore, hard copies of computer documents are often as important today as they were when the paperless revolution began several years ago.

Printers:  Color and quality

The choice between a black-and-white printer and a color printer depends on the needs of customers. A printer produces colors using subtractive mixing. The eye sees a color that reflects from the combination of colors on the paper. The colors are cyan, magenta, yellow, and black (CMYK). The quality is measured in dots per inch (dpi); the more dpi, the higher the resolution.



Printers: speed and capacity

Printer speed is measured in pages per minute (ppm): Inkjet Printer 2 - 6 ppm Laser Printer 8 - 200 ppm

Printers: reliability and cost

Factors of reliability include: Warranty, Scheduled servicing and Mean time between failures (MTBF) Total Cost of Ownership (TCO) includes: Initial purchase price, Cost of supplies, such as paper and ink, Price per page and Maintenance costs. Printer to computer interface To access a printer, a computer must have an interface with it. The following are common interface types: Serial, Parallel (Parallel data transfer is faster than serial data transfer),Universal Serial Bus (USB) is a common interface for printers and other devices nowadays, Firewire, Ethernet and Wireless.

Types of printers

· <span style="font-family: 'Comic Sans MS',cursive; font-size: 12pt;">Laser printer

<span style="font-family: Georgia,serif; font-size: 120%;">A laser printer is a high-quality, fast printer that uses a laser beam to create an image. The main components contained within a laser printer: Toner cartridge, Laser scanner, High-voltage power supply, Paper transport mechanism, Transfer corona, Fuser assembly, Control circuitry and Ozone filter.



· <span style="font-family: 'Comic Sans MS',cursive; font-size: 12pt;">Impact printer

<span style="font-family: Georgia,serif; font-size: 120%;">Impact printers form characters when the print head impacts a printer tape or inked ribbon to create characters. (Daisy-wheel and dot-matrix printers)
 * <span style="font-family: Georgia,serif; font-size: 120%;">__Advantages:__ uses inexpensive consumables, uses continuous feed paper and it has as copy printing ability(“carbon copies”)
 * <span style="font-family: Georgia,serif; font-size: 120%;">__Disadvantages:__ noisy, low resolution graphics, limited color capability, slow printing normally 32 to 76 characters per second.

· <span style="font-family: 'Comic Sans MS',cursive; font-size: 12pt;">Inkjet printer

<span style="font-family: Georgia,serif; font-size: 120%;">Use ink-filled cartridges that spray ink onto a page through tiny holes, or nozzles. The ink is sprayed in a pattern on the page, one column of dots at a time.
 * <span style="font-family: Georgia,serif; font-size: 120%;">__Advantages:__ produce high quality print, easy to use and inexpensive compared to laser printers.

· <span style="font-family: 'Comic Sans MS',cursive; font-size: 12pt;">Solid-ink printer

<span style="font-family: Georgia,serif; font-size: 120%;">Use solid sticks of ink rather than toner or ink cartridges. <span style="font-family: Georgia,serif; font-size: 120%;">Step 1: Cleaning <span style="font-family: Georgia,serif; font-size: 120%;">Step 2: Spraying <span style="font-family: Georgia,serif; font-size: 120%;">Step 3: Transferring
 * <span style="font-family: Georgia,serif; font-size: 120%;">The printing process:
 * <span style="font-family: Georgia,serif; font-size: 120%;">__Advantages:__ produces vibrant color prints, easy to use and can use many different paper types.
 * <span style="font-family: Georgia,serif; font-size: 120%;">__Disadvantages:__ expensive (the printer and ink) and slow to warm up.



<span style="font-family: 'Comic Sans MS',cursive; font-size: 110%;">· <span style="font-family: 'Comic Sans MS',cursive; font-size: 12pt;">Thermal printer

<span style="font-family: Georgia,serif; font-size: 120%;">A thermal printer uses chemically-treated paper that becomes black when heated. It uses heat-sensitive ribbon, which the print head melts onto the paper. It has a longer life because there are few moving parts. <span style="font-family: Georgia,serif; font-size: 120%;">· __Disadvantages:__ paper is expensive, paper has a short shelf life and images are poor quality, paper must be stored at room temperature.



· <span style="font-family: 'Comic Sans MS',cursive; font-size: 12pt;">Dye-Sublimation printer

<span style="font-family: Georgia,serif; font-size: 120%;">It usually used in producing photo-quality images for graphic printing. It uses solid sheets of ink that change directly from solid to gas when heated, in a process called sublimating <span style="font-family: Georgia,serif; font-size: 120%;">§ __Advantages:__ very high quality images, overcoat layer reduce smearing and increases moisture resistance. <span style="font-family: Georgia,serif; font-size: 120%;">§ __Disadvantages:__ media can be expensive and they are better for color than for grayscale (black and white ).



<span style="font-family: 'Comic Sans MS',cursive; font-size: 14pt;">Summary

<span style="font-family: Georgia,serif; font-size: 120%;">Printers output electronic files in the computer on to a paper. Most printers attach to the computer through some ports such as parallel port, but newer ones use USB connections. The quality of a printer measures by dot per inch (dpi) and its speed measures by paper per minutes (ppm). We can choose the best printer that will suite of our needs by seeing the quality and colors of the printer output (CMYK), capacity and speed, and the reliability and the cost. <span style="font-family: Georgia,serif; font-size: 120%;">There are many types of printers and each type has some advantages and disadvantages. <span style="font-family: Georgia,serif; font-size: 120%;">· Laser printer: is a high quality, fast printer that uses a laser beam to create the image.

<span style="font-family: Georgia,serif; font-size: 120%;">· Impact printer (Dot matrix): it has print heads that hit the inked ribbon to make characters to be imprinted on the paper.

<span style="font-family: Georgia,serif; font-size: 120%;">· Inkjet printer: It produces high quality prints. It uses ink cartridges that spray ink onto the paper through nozzles

<span style="font-family: Georgia,serif; font-size: 120%;">· Solid-ink printer: It uses solid stick of ink which the printer melts the ink sticks and sprays it through nozzles.

<span style="font-family: Georgia,serif; font-size: 120%;">· Thermal printer: it uses special papers that have the ability to be black when heated.

<span style="font-family: Georgia,serif; font-size: 120%;">· Dye-sublimation printer: it uses solid sheets of ink that directly change from solid to gas.

<span style="font-family: 'Comic Sans MS',cursive; font-size: 12pt;">Resource

<span style="font-family: Georgia,serif;">Cisco Networking Academy Program Website