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The most common computer output device is the monitor or computer screen. Monitors create a visual display from processed data that users can view. They come in a variety of screen sizes and visual resolutions.
There are two types of computer monitors, CRT and flat panel. CRT monitors use phosphorescent dots to create the pixels that make up display images. Flat panel monitors usually use LCD or plasma to create output. Light is passed through liquid crystals to create the pixels.
All monitors rely on a video card that is located on the computer motherboard or in a special expansion slot. The video card processes the computer data into image details that the monitors can display. -
Printers produce a hard copy version of processed data such as documents and photographs. The computer sends the image data to the printer, which then physically recreates the image onto an object.
There are three types of computer printers: ink jet, laser and dot matrix. Inkjet printers spray tiny dots of ink on a surface to create an image. Laser printers use toner drums that roll through magnetized pigment and then transfer the pigment to a surface. Dot matrix printers use a print head to imbed images on a surface, using an ink ribbon. - Computers produce audio data that require output devices such as speakers and headphones to deliver the sound to the user. Audio data is created by the computer and then sent to the audio card, which is located in an expansion slot. The card translates the data into audio signals, which are sent to the audio output device.
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CD, DVD and floppy disc are output devices that can also be used as storage and input devices. The computer sends data to the disc, where it is embedded and can be later retrieved.
Compact disc, or CD, is an optical device that stores audio and visual data in a digital format. Data is placed on the disc, using a laser writer that embeds the data into the disc's coating.
Digital Versatile Disc, or DVD, is an optical device that stores visual data in a media format. DVDs feature a dual coating system that allows audio and visual data to be written at the same time by using a laser.
Floppy disc is a magnetic storage device. A layer of magnetized material is placed within a proactive plastic casing. The computer embeds the data into the magnetized material, using a writing head. - Projectors are display devices that project a computer created image. The computer sends the image data to the video card which then sends the video image to the projector. They are typically used for presentations or for viewing videos.
- Plotters create a hard copy rendition of a digitally rendered design. The design is sent to the plotter via a graphics card, and creates the design using a pen. Generally used with engineering applications, plotters basically draw an image using a series of straight lines.
