What is LED Display Board Working Principle

Presently, LED display board can be viewed at any where in our daily lives with the rapid development of technology, but it is mainly used for commerce and media advertisement, big publish conference, gymnasium, entertainment activities, etc.

LED display board is made up of many unit modules, each unit module is made up of LED chips.

Currently, most of LED display boards which are manufactured by LED display manufacturers are SMD LED Chips, each LED with R,G,B is encapsulated in a lamp-holder, the brightness is different with different size, the three primary colors of each LED chip is one pixel. The combination of R, G, B is white, the combination of R+G is yellow, G+B is purple, R+B is navy. Please view below picture.

Each frame picture is made up of specified lighting colors which is formed by thousands of LED chips, the variation of one frame by one frame creates the animation that we can watch. Then how to know the brightness of R,G,B for each LED chip? Here we need learn about the scanning modes of LED display board. The scanning modes can be classified as static scanning and dynamic scanning. The static scanning is that each lighting color of LED chip is directly corresponding to the driving IC of each unit board, each driving IC just can accept the Red color of 16 LED chips (Each driving IC just has 16 lamp-holders to transmit Red to LED chip), by this way, each color of 16 LED chips at least need three driving IC to light, this manufacturing cost is high, but the display effect is well (Currently, there are so scarce suppliers to manufacture this kind of driving LED display board).

The dynamic scanning also can be classified as 2 scanning, 4 scanning, 8 scanning and 16 scanning, etc. Dynamic scanning is that the lamp-holder of one driving IC just controls one variety color of one LED chip, then 2 scanning is that the lamp-holder of one driving IC just controls one variety color of two LED chips, 4 scanning is the lamp-holder of one driving IC just controls one variety color of four LED chips, 8 scanning is the lamp-holder of one driving IC just controls one variety color of eight LED chips, and so forth.Taking 8 scanning as example, that is the lamp-holder of one driving IC to control one variety color of 8 LED chips. Then we need use row signal control circuit to realize the brightness or dark for the 8 LED chips. Now we want to the third LED chips to be lighting, how to operate other 7 LED chips? Please check below picture, the row signal electrification (usually it is anode) is whole of row, the 8 LED chips which is controlled by one lamp-holder of driving IC would be intersecting with row signal, the LED chip which is at the intersection area would be lighting.

Above is the basic working principle for LED display board, our human being can’t feel this variation attributing to the refreshing ratio of LED display board is very high, it can be saw from debugging device, it is basically above 200Hz, each color of LED chip continue to bright and dark to form one frame by one frame picture under high refreshing ratio, one frame picture by one frame picture continue variation to form animation.

This  articl  comes from szrlled edit released