The scanning principle of LED display

  With the rapid development of the LED display industry, LED technology is also constantly developing, the brightness of LED displays is also constantly improving, and the size is getting smaller and smaller, which indicates that more LED displays will enter indoors and will become a major trend. However, the increase in LED brightness and density has brought new and higher requirements to the control and drive of LED displays. At present, the general control method of general indoor LED displays adopts the row and column control mode, which is usually called the scanning mode. At present, the driving modes of LED electronic displays are static scanning and dynamic scanning. Static scanning is divided into static real pixels and static virtual, and dynamic scanning is also divided into dynamic real images and dynamic virtual.

  In the LED display screen, the ratio of the number of lines lit at the same time to the number of lines in the entire area is called the scanning mode. The scanning is divided into several driving modes such as 1/2 scanning, 1/4 scanning, 1/8 scanning, and 1/16 scanning. It can also be said that the driving mode of the display screen is different, so the settings of the receiving card are also different. If the receiving card was originally used for 1/4 scanning evaluation and is now used on a static screen, the display of the display screen will light up one line every 4 lines. Generally, the receiving card can be set. After connecting the sending card, display screen, computer and other main components, you can enter the relevant software on the computer to set it up. So here we will first introduce the scanning mode and principle of the LED display screen.

1. LED display screen scanning mode

(1) Dynamic scanning: Dynamic scanning is to implement "point-to-column" control from the output of the driver IC to the pixel points. Dynamic scanning requires a control circuit and is cheaper than static scanning, but the display effect is poor and the brightness loss is large.

(2) Static scanning: Static scanning is to implement "point-to-point" control from the output of the driver IC to the pixel points. Static scanning does not require a control circuit and is more expensive than dynamic scanning, but has the advantages of good display effect, good stability, and small brightness loss.

2. Working principle of 1/4 scanning mode of LED display screen

The working principle of 1/4 scanning mode of LED display screen is that in 1 frame of image, each row of power supply V1-V4 is turned on for 1/4 of the time according to the control requirements. The advantage of this is that it can more effectively utilize the LED display characteristics and reduce hardware costs. The disadvantage is that in 1 frame of image, each row of LED can only be displayed for 1/4 of the time.

3. Classification of scanning methods according to LED display type

(1) Scanning method of indoor full-color LED display screen: P4 and P5 are constant current 1/16, P6 and P7.62 are constant current 1/8.

(2) Scanning methods of outdoor full-color LED display screens: P10 and P12 are constant current 1/2 and 1/4, and P16, P20, and P25 are static.

(3) The scanning methods of single and double-color LED display screens are mainly constant current 1/4 scanning, constant current 1/8 scanning, and constant current 1/16 scanning.