scince behind cathode ray tube television

Scince behind cathode ray tube television full#

Every pixel is made up of three separate subpixel cells, each with different colored phosphors.

The phosphors in a plasma display give off colored light when they are excited. When the electron falls back to its normal level, it releases energy in the form of a visible light photon. When an ultraviolet photon hits a phosphor atom in the cell, one of the phosphor's electrons jumps to a higher energy level and the atom heats up. Phosphors are substances that give off light when they are exposed to other light. The released ultraviolet photons interact with phosphor material coated on the inside wall of the cell. As we saw in the last section, the current creates a rapid flow of charged particles, which stimulates the gas atoms to release ultraviolet photons. When the intersecting electrodes are charged (with a voltage difference between them), an electric current flows through the gas in the cell. It does this thousands of times in a small fraction of a second, charging each cell in turn. To ionize the gas in a particular cell, the plasma display's computer charges the electrodes that intersect at that cell. On the next page, learn how the plasma works.

Scince behind cathode ray tube television full#

Just like a CRT television, the plasma display varies the intensities of the different lights to produce a full range of colors. Each pixel is made up of three fluorescent lights - a red light, a green light and a blue light. The basic idea of a plasma display is to illuminate tiny, colored fluorescent lights to form an image. By combining these colors in different proportions, the television can produce the entire color spectrum. In most systems, there are three pixel colors - red, green and blue - which are evenly distributed on the screen. Based on the information in a video signal, the television lights up thousands of tiny dots (called pixels) with a high-energy beam of electrons. If you've read How Television Works, then you understand the basic idea of a standard television or monitor. In this article, we'll see how these sets do so much in such a small space. These televisions have wide screens, comparable to the largest CRT sets, but they are only about 6 inches (15 cm) thick. Consequently, any big-screen CRT television is going to weigh a ton and take up a sizable chunk of a room.Ī new alternative has popped up on store shelves: the plasma flat panel display. In order to increase the screen width in a CRT set, you also have to increase the length of the tube (to give the scanning electron gun room to reach all parts of the screen). The television image is produced by lighting up different areas of the phosphor coating with different colors at different intensities (see How Televisions Work for a detailed explanation).Ĭathode ray tubes produce crisp, vibrant images, but they do have a serious drawback: They are bulky. The electrons excite phosphor atoms along the wide end of the tube (the screen), which causes the phosphor atoms to light up. In a CRT television, a gun fires a beam of electrons (negatively-charged particles) inside a large glass tube. Peter Cade / Getty Imagesįor the past 75 years, the vast majority of televisions have been built around the same technology: the cathode ray tube (CRT). Over the years, plasma has become the new norm for screens.