projector

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Apparatus that projects a picture on to a screen. In a slide projector, a lamp shines a light through the photographic slide or transparency, and a projection lens throws an enlarged image of the slide onto the screen. A film projector has similar optics, but incorporates a mechanism that advances the film and then holds it still while light is transmitted through each frame (picture). A shutter covers the film when it moves between frames. A television projector, often used at sports events, produces an enlarged image of the television screen. It shines an intense light through a small LCD (liquid crystal display) throwing the television picture onto a large screen. A digital projector is used for computer-aided presentations. The oldest types use cathode-ray tube technology. One newer type has LCD screens like those used in calculators and flat-screen televisions, through which light shines onto the screen. A third type has a million or more tiny mirrors mounted on a microchip. Each mirror can be deflected or vibrated to control the light going to a single pixel (picture element) in the image.

Yellow symbolizes the golden land of South America. Red stands for courage and the blood of the freedom fighters. Blue represents the ocean separating South America from Spain. Effective date: 17 February 1954. >>