Video LED screen is in fact a large television set. Unlike TV, LED systems are made of separate LED modules into video screens of different sizes and shapes.
Information is relayed to LED modules by controllers which are connected to the controlling computer. A video processor in a PC receives video signals from different sources - standard TV signal, signal from the VCR, DVD-player, video camera, another computer and so on.
Video clips prepared in advance could be recorded on hard drive of the controlling computer and could be displayed according to a required schedule.
When sufficient number of video LED screens was installed, a new idea of connecting all of these LED screens into a network with the unified control center emerged. Separate standing LED screens are controlled by a central computer through any of the available channels - modem, radio modem, fiber-optics, etc.
Modular construction of LED screens
Standard TV signal on a LED screen with different aspect ratio will be distorted or shown on the different parts of the screen.As it was already mentioned, video LED screens are made of LED modules. On the picture there is an example of construction of the video LED screen's modules with the linear size of 240x240 mm, pixel pitch 15 and ratio of the sides (width : height) - 4:3.
If the LED screen is used only for the broadcasting of special video clips prepared in advance, then the aspect ratio does not play such important role and can be changed according to customer's request.