The monitor is a peripheral (peripheral device) bright graphic display output data and images, commonly used in telecommunication equipment and data processing technique. The data are represented by characters and symbols. A monitor is constructive originally a TV without the TV signal reception antenna.
Used in closed circuit television, for example the airport, airport to monitor different areas from a distance, and therefore does not need to absorb or process signals from network TV. In such cases come through the wire video signals directly from cameras within a closed circuit.
All monitor speakers are called and some additional monitoring and control.
In time, by extension, monitor (also called screen display and sometimes VCR) has been called the computer peripheral equipment with which displays complementary information and is done with the keyboard command and / or communication between user and computer. In this case the monitor is considered a graphical user interface or GUI Graphic User Interface).
First monitors could only display text information and only in two colors (green, red or yellow on black and black on gray or white), unlike the current ones which can display moving images with billions of color tones.
Initially, the diagonal sizes of the tubes used were small: 8, 9, 10, 12, 14, 15 inches. Currently, the usual values of type CRT monitors (with tube) are 15, 17, 19, 20, 21, 22, 24 or to 27 inches.
The size of a screen surface is frequently determined the distance between two opposite corners of it. But it is a problem that the measurement method does not distinguish between exact geometric shapes monitors identical diagonal sizes in that area determined by a diagonal decreases (relative to the square), with both screens become more rectangular. For example, a 4:3 monitor 21 “has an area of ~ 211 square inches, while a 16:9 21″ has an area of only ~ 188 square inches.
This method of measurement relatively imprecise, dates back to early versions of the CRT TV tubes were frequent round use. They had one dimension that describes the size of the screen. When round tubes were used to display images rectangular diagonal size was equivalent to the diameter of the tube.
