Key terms for LED display
The LED screen is composed of thousands or millions of LED chips, size from micro-meters(um) to mini-meters (mm), this basic display unit is pixel, the smaller pixel, the higher resolution of the display.
Surface Mount LED chips (SMD type) are widely used in LED displays, usually there are 4 pins on the chip, 1 common, either common annode or common cathode, 3 for red, green, blue respectively,
Size of the pixel or the LED chip is from 1.0x1.0 mm, 1.5x1.5mm , 1.9x2.1mm, etc. which are nominated as SMD1010, smd 1515, smd1921, etc.
Pay attention to the size of the LED, even in the same pixel pitch, there are different pixel size, ie, in a P2.5 250x250 mm module, there is SMD1515 or SMD1921, usually in the same size, same pixel pitch module, smaller pixels have bigger seam.
Pixel pitch, the distance of the adjacent pixels measured from center to center. In the screen, the smaller the pixel pitch, the greater the number of pixels, the higher the resolution. Pixel pitch for indoor screen goes as small as to 0.4 mm, popular outdoor screen goes to 3.9 mm.
Concerns for outdoot display
Bright Enough
If it is a billboard, the display facing the sunshine must be twice the brightness of the sunlight, which is greater than 3000 nit,
Water-proof
Strucuture to be stubborn enough to stand strong wind.
In doing so, a metal structure is needed.
Due to the nature of LED chips, there is heat generation in working, the higher the brightness, the higher the power is supplied, the higher the heat is generated. So large outdoor LED displays will require a good ventilation or cooling system.