Print Head

A computer printer is a computer peripheral device that produces a hard copy (permanent human-readable text and/or graphics, usually on paper) from data stored in a computer connected to it. The world's first computer printer was a 19th-century mechanically driven apparatus invented by Charles Babbage for his Difference Engine.

Methods of image creation

The medium for most printers is paper, so they are usually classified according to the method of image creation:

Toner-based printers

Laser printers refer to the method used to adhere toner to the media. The advent of cost-effective, precision lasers has made them the dominant toner-based monochrome printer type for home and office applications. Another toner based printer is the LED printer which uses an array of LEDs instead of a laser to cause toner adhesion.

Inkjet printers

Inkjet printers spray very small, precise amounts (usually a few picolitres) of ink onto the media. For color applications including photo printing, ink jet methods are dominant. Inkjet printers or bubble-jet printers are one of the most commonly used printers. They consist of nozzles that produce very small ink bubbles that turn into tiny droplets of ink. The dots formed are the size of tiny pixels. Ink-jet printers can print high quality text and graphics. They are also almost silent in operation. They are cheaper than laser printers, but are expensive to run as their cartridges need to be frequently replaced.

Impact printers

Impact printers rely on a forcible impact to transfer ink to the media, similar to typewriters, that are typically limited to reproducing text. A daisy wheel printer is a specific type of impact printer where the type is molded around the edge of a wheel. A golf ball typewriter is similar to the daisy wheel type but has the characters distributed over the face of the globe shape.

Dot-matrix printers

In the general sense many printers rely on a matrix of pixels, or dots, that together form the larger image. However, the term dot matrix printer is specifically used for impact printers that use a matrix of small pins to create precise dots. The advantage of dot-matrix over other impact printers is that they can produce graphical images in addition to text; however the text is generally of poorer quality than impact printers that use letterforms (type).

This article is adapted from: wikiPedia.com.