3.1+IO+Printers+monitors+speakers+and+projectors

There are main types of computers
 * __3.1 IO Printers, monitors, speakers and projectors- Outputs __**
 * Dot Matrix printer
 * Inkjet printer
 * Laser printer
 * Thermal printer
 * LED printer

The most popular printer for home computer users that prints by spraying streams of quick-drying ink on paper. The ink is stored in disposable ink cartridges, often a separate cartridge is used for each of the major colors. These colors are usually Black, Red/Magenta, Green/Cyan, and Yellow. In the picture to the right, is an example of a computer inkjet printer.
 * Injet Printers**

A **laser printer** is a printer that utilizes laser technology to print images on the paper. Laser printers are often used in corporate, school, and other environments that require print jobs to be completed quickly and in large quantities. In the picture to the right, is an example of what a laser printer may look like.
 * Laser Printers**

__Steps of a Laser Printer__
 * **Step** || **What it does** ||
 * **Cleaning** || Removes prior image information and toner from the drum. ||
 * **Conditioning** || Applies a uniform negative charge to the drum. ||
 * **Writing** || Light source such as lasers, LED, or LCS (Liquid Crystal Shutter) write to areas on the drum discharging the negative potential where it hits. ||
 * **Developing** || The toner is ionized with a negative charge and is attracted to the areas previously written (discharged) on the drum. ||
 * **Transfer** || The toner of the drum is transferred to the paper by either a positively ionized field (created by a transfer corona wire) or by a transfer roller in newer printers. The toner is not yet permanently set on the paper and requires the last stage. ||
 * **Fusing** || Heat and pressure are applied to the paper and toner. The toner melts and then is pressed to the paper like doing an iron-on transfer to a T-shirt. ||

__**Monitors**__ Also called a **video display terminal (VDT)** and **video display unit (VDU)**, a**monitor** is a video display screen and the hard shell that holds it. In its most common usage, monitor refers only to devices that contain no electronic equipment other than what is essentially needed to display and adjust the characteristics of an image.

Like most TVs, the computer monitor has a CRT (Cathode Ray Tube) that is found inside the computer monitor as illustrated in the picture to the right. The CRT is the main component and most expensive part within your computer monitor.

Flat Panel Display

Thin screen displays found with all portable computers and becoming the new standard withdesktop computers. Instead of utilizing thecathode-ray tube technology **flat-panel displays**use Liquid-crystal display (LCD) technology or other alternative making them much lighter and thinner when compared with a traditionalmonitor.

__**Speakers**__ A hardware device connected to a computer's sound card that outputs sounds generated by the card. When computers were originally released they had onboard speakers that generated a series of different tones and beeps. As multimedia and games became popular, higher quality computers speakers began to be released for higher quality sound effects and music. Computer sound cards today are not powerful enough to power a nice set of speakers. Today, good quality speakers are self-powered, relatively small in size to fit on desks or on the side of monitors and contain magnetic shielding. Speakers are generally rated in Frequency response. __**Projectors**__ An output device that can take the display of a computer screen and project a large version of it onto a flat surface. **Projectors** are often used in meetings and presentations so that everyone in the room can view the presentation. In the picture to the right, is aViewSonic projector and an example of what a projector may look like. Projectors used with computers are small devices that are rarely much larger than a toaster and typically weigh a few pounds.