An Overview of Printers

Printers are most commonly used output devices used to get prints of documents on the paper. The output printed on the paper is called hard copy. The hard copy is also called as print out. The print out resolution is measured in dots per inch. A printer is connected to a parallel port or a USB port of a system unit by a cable.

Printing, reduced to its basics, is the art of moving ink from one place to another. Although that definition likely will please only a college instructor lost in his own vagueness, any more precise description fails in the face of a reality laced with printouts of a thousand fonts and far fewer thoughts. A modern computer printer takes ink from a reservoir and deposits it on paper or some other medium in patterns determined by your ideas and computer. In other words, a printer makes your thoughts visible.

Behind this worthy goal is one of the broadest arrays of technology in data processing, including processes akin to hammers, squirt guns, and flashlights. The range of performance is wider than with any other peripheral. Various printers operate at speeds from lethargic to lightning-like, from slower than an arthritic typist with one hand tied behind his back to faster than Speedy Gonzales having just munched tacos laced with amphetamines. They are packaged as everything from one-pound toteables to truss-stressing monsters and look like anything from Neolithic bricks to Batman's nightmares. Some personal-size printers dot paper with text quality that rivals that of a professional publisher and chart out graphics with speed and sharpness that puts a plotter to shame. Some make a two-year-old's handiwork look elegant.

Printer technology predates the video display system. In fact, printing is far older than the personal computer, computers in general, or even electronics. It can trace its inky roots back at least as far as Johannes Gutenberg, who first slathered ink on slugs of lead and squeezed it onto paper over 500 years ago (he printed his famous 42-Line Bible in Mainz, in what is now Germany, in 1455).

Gutenberg didn't invent the ink-transfer process. His insight was to subdivide the woodblocks used for making page-size prints of pictures into reusable pieces. Instead of wood, with its limited life, he cast his characters out of rot-free metal. Each alphabetic letter became its own metal printing block. In effect, Gutenberg invented character-based technology that served the first generation of computer printers so well.

The latest printing technologies simply take Gutenberg to the extreme, subdividing the printed character and producing the ink-equivalent of video's all-points-addressable graphics. The technology divides each character into a matrix of minuscule dots and prints them individually. The arrangement of dots makes each character—or forms the bright and dark parts of a graphic image. The dots have gotten smaller and the detail produced greater as computer technology and the ability to control the placement of individual dots has improved.

Thirty years ago, about the best printing technology had mastered the ability to place an entire character as a single piece on paper, squeezing ink out all at once, much like Gutenberg, as the fully formed character printer. Today, a character made by a laser printer may comprise 10,000 dots, each one individually controlled.

At one time, printing had two faces. Commercial printing was Gutenberg's offspring, the process of making multiple copies by mass production. Computer printing was more concerned with making individual copies. Computer printers, like the first typewriters (raise your hand if you remember what a typewriter is), used mechanical means to make each page look more readable, translating electronic data into ink form.

Today, however, the lines are blurring. The personal printers you attach to your computer are just as apt to be publishing engines that crank out pamphlets, fliers, and newsletters as they are individual page-makers. Commercial printing presses are going electronic and are just as capable of printing single pages as any desktop machine. Commercial printing presses may, in fact, use the same technologies as the desktop printer, though on a more massive scale.

Different printers have different printing mechanisms. Therefore printers are callisified into 2 categories depending upon their printing mechanisms. These are:

1. Impact Printers
2. Non-Impact Printers

1. Impact Printers

An impact printer prints characters and graphics on the paper with the strikes of hammer on a ribbon. A simple example of an impact printer is typewriter, which uses small hammers to strike the ribbon. Each hammer is embosed witht the shape of alphanumeric character; that shape is printed on the paper through inked ribbon. there are many types of impact printers but the most popular and commonly used is the dot matrix printer.

2. Non-Impact Printers

Thr printers that produce the output on a paper without striking the paper are known as non-impact printers. They use electro static, chemicals, ink jet and thermal technologies for printing. The main features of non-impact printers are:

• Faster than impact printers.
• Print high quality output.
• Produce no noice during printing.

The examples of non-impact printers are; Laser printer, Inkjet printers etc.