You communicate everyday with your computer via the computer's monitor. The monitor is the screen that displays the programs you are running, the images and text documents, and all sorts of other information! Unlike most other parts of your computer, the monitor does not perform any calculations or operations. Instead, it is merely responsible for conveying all of the information to you by displaying it on a screen.
Most monitors are based on the CRT, or cathode ray tube. Cathode ray tubes are glass tubes that are narrow at one end, and open up to a wide screen at another. They are the display devices of the monitors. Cathode ray tube monitors consist of three basic parts:
The electron guns start at the upper left hand corner of your computer screen. They fire electrons left to right along the top of your screen, then they move down a line. This continues until the whole screen is finished. Your computer screen is divided into tiny sections called pixels. A pixel consists of one red, one blue, and one green phosphor dot. They line up in rows and columns to form your screen, and are so small that they appear to all be connected!
2. Steering Magnet (focusing coil):
3. Phosphor Coated Screen:
The phosphors on your computer screen light up and glow for a short while after they have been struck by the electron gun. This is what creates the images seen on your computer screen. For different colors, different combinations of the triads are struck, and this can create a full color spectrum! You might also notice that you can control the brightness of your computer screen. The brightness of each pixel is determined by a video data stream that is coming out of your computer's video card. The video cards are responsible for the different graphics and images your computer can use! However, because the phosphors only light up for a short while, the electron gun has to continuously redraw the image. This is known as "refreshing."
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