Somehow unnoticed is the time when the shelves almost completely disappeared TVs and monitors based on cathode-ray technology.Recall, these are the bulky devices that occupy almost half of the computer desktop.It is now the thickness rarely exceeding 10 cm, and considering only the illumination lamp.Not surprisingly, many happily forgotten that a CRT monitor.And in vain!Although, if only because in some ways it is even ahead of the latest liquid-crystal counterparts.
How are CRT monitors
First of all, let deciphering abbreviations.Thus, the term "CRT" is meant electron beam or, as we pointed out earlier, the cathode tube (from the English. CRT - Cathode Ray-Tube).As a rule, the word "tube" most people are cylinder, the ends of which there is no wall.Speaking of what a CRT monitor, it is necessary to mention that in this case the idea is wrong.Because the shape of the tube it is far from the cylindrical plane and extends to one side.This surface is a front glass portion, the one on which images are formed.The inner side of the site is covered with a special substance - phosphor.Its unique feature is that when struck by a stream of charged particles the kinetic energy is converted into a natural glow.Thus, a CRT monitor is a device in which the electron beam rays silhouetted inner side of the screen image.Man sees it, thanks to glow phosphor.
the other side of the flask is placed a block of electrodes, called guns.They create a stream of particles.
In other words, the CRT monitor consists of a glass tube, electrodes, and a control circuit guns.
principle of operation is known, mixing a certain ratio of the three primary colors: green, red and blue - you can get all the rest, including shades.The color monitors the entire inner surface of the screen is composed of pixels, conventionally grouped into triads (block 3 pieces).Each of them can illuminate one of the primary colors.And three electrodes, each of which highlights "his" point.In a certain manner and igniting passing them on the screen, it is possible to form a color image.By the way, in devices in black and white only one gun.
to control the flow of particles using electromagnetic deflection and initial direction of their movement created due to the potential difference.
Since technically quite difficult to ensure the accuracy of the beam falling on his point, use a special solution - the mask.Relatively speaking, this is a perforated grid between screen and guns.There are different types of masks.Part of it is they who are responsible for the particular display (sharpness, shape points-pixels).
Since after hitting glow phosphor particles decreases very rapidly, it must be constantly re-create the image.Both static and dynamic.Therefore rays draw in detail the image ten times per second.This is the famous Hertz vertical deflection.The higher the frequency, the less noticeable flicker.
Currently, repair of CRT monitors for subsequent use in a computer system would be inappropriate, as the modern LCD technology is more promising.Exception - a specific use.
