CRT (Cathode Ray Tube) display SCREEN systems

The CRT screens are named so due to the type of the used indication elements - CRT lamps.

In CRT lamps the current passes through gas environment and changes gas condition. The gases become conductors as a result of their ionization. Originally in cathode ray tubes gas discharge was carried out not independently. Then it develops into independent and then into stationary. The electrical discharge occurs under AC voltage.

Basically there exist 2 different types of gas-ischarging displays / screens / signs. The 1st is based on a cathode-ray principle (CRT) produced by Sony, Panasonic with brightness 10000-15000 cnd/m2; the second type uses luminescent gas tubes with brightness up to 5000-15000 cnd/m2. They are produced, for example, by MEGALUX Kft (Hungary).

CRT signs / displays / screens produced by MEGALUX Kft (Hungary) are much cheaper (8000 - 20000 $) than signs produced by Sony, Panasonic, the cost of square meter of which exceeds 24000 $. The company began its research work in 1990. The first stage of work was completed in 1991. In 1992 in Budapest a full color video sign (6x12m) was installed in Blaha Luisa square. It works till now.

Then, a scoreboard at the National STADIUM in Budapest was replaced. This screen has a full color video surface & the area of 140 sq. meters, monochrome watch matrix surface with the area of 6 sq. meters and also the watch of the exact time 3, 5m in diameter.

The intensity of light is sufficient for the formation of the image that can attract attention. The control system allows to work with the video image in three dimensions. Thus, the use of "picture in picture" effect, manufacture titles on the background of the video image, smooth movements of the images and also the use of other modern effects become possible.

The CRT displays / screens on the basis of cathode-ray-tube principle or Jumbo produced by Sony, Panasonic and also in China with brightness of 10000-15000 cnd/m2 have high quality of image, are much brighter than led signs and their brightness doesn't concede to the majority of lamp screens, but their Price!!! – it`s more than 2-3 times more expensive than led systems, and 3-5 times more than lamp ones.

There are some news that electronic CRT signs / screens are being produced in Russia in “Volga” Institute now. Its brightness, nevertheless, does not exceed 6 000 - 8 000 cnd/m2 and its price is higher than that of lamp systems of new generation. We don`t have other sufficient information concerning reliability and repair ability.

The CRT signs produced by MEGALUX Kft (Hungary) also concede lamp systems practically in all characteristics. Besides, the experience of the experts operating “Mega” electronic sign installed at "Petrovsky" stadium in St.-Petersburg, shows that CRT screen managing schemes and the blocks of ignition are not reliable and frequently burn out. One CRT cylinder maintains no more than 2000 hours of continuous work, that is its life span is much shorter than that of lamps. As there is no power supply stabilizing system, safety fuses & blocks of ignition frequently burn out. Besides, a special system of cooling and heating is necessary for normal functioning in various temperature modes. And the last thing is that the manufacturing term of the electronic screen is 5-7 months, that is 2-3 times longer than the assembly of lamp displays.

Examples of CRT screens