What is the scanning mode of LED unit board?

     An LED panel, such as an indoor panel of 3.75, is 32 rows high. We also said that the LED panel is displayed line by line. However, it is found that in order to achieve a certain brightness of the LED display screen, it is necessary to make each luminous tube reach a certain display time. On the basis of maintaining such display time, if 32 lines are displayed one by one, the whole time will exceed the visual retention time of the human eye, and the human eye will feel that these 32 lines are displayed several times. Sequentially, this is certainly unacceptable for an LED display. So people came up with a solution. A 32-line LED panel is divided into two parts: the upper 16 lines and the lower 16 lines. Then the red and green signals are divided into two channels, each of which controls 16 rows up or 16 rows down. At the same time, select two lines to display simultaneously on the 32-line cell board, for example, select the first line in the top 16 lines and the first line in the bottom 16 lines at the same time, because the two lines are controlled by two signals respectively, so they can be displayed at the same time. In this way, only 16 rows of total display time on the LED panel is required to be less than the visual retention time of the human eye, which can properly lengthen the display time of each row of light emitting tubes, so that the LED display screen can achieve a certain brightness. This kind of display mode, for the LED display screen, is displayed at the same time every 16 rows. That is, at the same time, the first line in 32 lines (the first line in the top 16 lines) and the seventeenth line (the first line in the bottom 16 lines) are displayed simultaneously, similarly, the second line and the eighteenth line are displayed simultaneously, and so on. This display mode, which is displayed every 16 rows at the same time, is called 1/16 scanning mode. According to the practical application requirements, it is not difficult to imagine that the brightness of outdoor panel should be higher than that of indoor panel. So how to increase the brightness of the outdoor panel? Still follow this train of thought and continue to partition the unit board. Experiments show that after dividing the 16-line-high P10 outdoor panel into two 8-line areas, the brightness is still insufficient, so it will continue to be divided into four 4-line areas, so that four rows are bright at the same time, so that only the total time of displaying four rows on the panel is less than the visual retention time of the eyes, which can effectively increase each line. A row of luminescent tubes brighten the time, thereby increasing the overall brightness. This display mode, which displays at four rows at the same time, is called the 1/4 scan mode, and is usually used on the P10 outdoor panel. In addition, there are 1/8 or 1/2 scanning mode. The principle is the same as above, so it is not necessary to elaborate.

     In a certain display area, the ratio of the number of rows illuminated at the same time to the number of rows in the whole area is called scanning mode; indoor monochrome and bichrome scanning is generally 1/16, indoor full-color scanning is generally 1/8, outdoor monochrome and bichrome scanning is generally 1/4, outdoor full-color scanning is generally static.

     At present, there are two driving modes of LED display screen in the market: static scanning and dynamic scanning. Static scanning can be divided into static real pixel and static virtual, and dynamic scanning can also be divided into dynamic real image and dynamic virtual. Drivers generally use domestic HC595, Taiwan MBI 5026, Toshiba TB62726, generally have 1/2 scan, 1/4 scan, 1/8 scan, 1/16 scan. Sweep.

     Illustration: A commonly used full-color module has 16*8 pixels (2R1G1B). If driven by MBI5026, the total number of modules used is:

     16*8* (2+1+1) = 512, MBI 5026 is 16-bit chip, 512/16 = 32

     (1) If 32 MBI 5026 chips are used, they are static virtual.

     (2) If 16 MBI 5026 chips are used, it is dynamic 1/2 scan virtual.

     (3) If 8 MBI 5026 chips are used, it is dynamic 1/4 scan virtual.

     If two red lights are connected on the board

     (4) With 24 MBI 5026 chips, it is a static real pixel.

     (5) Using 12 MBI 5026 chips, it is dynamic 1/2 scan real pixels.

     (6) Six MBI 5026 chips are used to scan 1/4 of the real pixels dynamically.

     In the LED unit board, the scanning mode is 1/16, 1/8, 1/4, 1/2, static. What about the distinction? One of the easiest ways is to count the number of LED units and 74HC595 units.

     Calculating method: divide the number of LEDs by the number of 74HC595 and then divide by 8 = 1/1 scan

     The difference between 16, 8 and 4 scans

     1. Different scanning methods;

     2. Different brightness (16s less than 8s less than 4s);

     3. The price is different, or the number of driving IC used is different (the same model 16S is less than 8s is less than 4s)

     At present, the display screen on the market can be roughly divided into static scanning and dynamic scanning. Static scanning is divided into static real pixels and static virtual! Dynamic scanning can also be divided into dynamic real image and dynamic virtual `2 scans, 4 scans, 8 scans and 16 scans respectively.

     Illustration: A commonly used full-color module: 16*8 (2R1G1B) MBI5026 driver, the total number of lights used in the module is: 16*8* (2+1+1) = 512, MBI5026 is 16-bit chip!

     (1) 512/16 = 32, if 32 MBI 5026 chips, this board is static virtual

     (2) If two red lights are connected in series on the board and 24 MBI5026 chips are used, they are static real pixels.

     (3) 12 MBI 5026 chips, dynamic 2-scan real pixels

     (4) 16 MBI 5026 chips, dynamic 2-sweep virtual

     (5) 8 MBI 5026 chips, dynamic 4-scan virtual

     (6) 6 MBI 5026 chips, dynamic 4-scan real pixels

Source: Display Home