Full color LED display drive mode detailed you must not know

Time:2018-10-29 Views:211

Full color LED display screen drive mode you must not know, according to statistics, in the full color LED display screen series of products, the scanning method is 1/16, 1/8, 1/4, 1/2, static.How to distinguish between different LED full-color screen scanning methods?What‘s the difference between them?

Current market LED full color screen drive mode can be roughly divided into static scanning and dynamic scanning two methods!Static scanning is divided into static real pixels and static virtual!Dynamic scanning is also divided into dynamic real image and dynamic virtual, with 2 sweeps, 4 sweeps, 8 sweeps and 16 sweeps respectively.

I. advantages/disadvantages of LED full color screen dynamic drive:

The advantage is that the display drive circuit is simple,2 IC can drive 8 leds under 10", the cost is low.Various sizes of LED can be directly connected with the main control board. Drive board. Expansion board, even without PCB board.Low power consumption.The power consumption is only 1/5 of that of static display.

The disadvantage is that there are many connections between LED and drive plate (a total of 8+LED number roots).When the number is large, the connection and maintenance are inconvenient.

Ii. Advantages/disadvantages of static drive of LED full color screen:

The advantage is that the connection between LED display components is very simple, only 5-6 wires are needed to connect all LED in series, which is convenient for debugging and maintenance.The display brightness is good. The LED below 2 meters can be driven by the appropriate driving element, which is suitable for making large outdoor digital screen.

The drawback is that each LED needs 1-2 driving IC, and PCB board of display component needs to be made.Power consumption is higher (five times higher than that of a scanning drive).The cost is slightly higher (the average cost per display drive is 0.4-1 yuan higher than the scanning drive).

Iii. LED full-color display driver chip is classified into the following two types:

1. General chip

The most commonly used chip is 74HC595. It has the functions of 8-bit latch, string -- and shift storage and three-state output.Each channel can output up to 35 mA of current (not constant current).

2. Special chip

One of the biggest features of the dedicated chip is the supply of constant current source. As the full-color LED display screen is a current characteristic device, that is, under the condition of saturation conduction, its brightness changes with the change of current size, rather than with the change of voltage at both ends.Constant current source can guarantee the stable drive of LED and eliminate the shining phenomenon of LED.