The working principle of the scanning mode of the LED display mainly involves how the LED screen can realize the display of images and text by lighting up the LED lights row by row or column by column.
The following is a detailed description of the working principle:
Basic scanning principle
The scanning principle of the LED display refers to lighting up the LED lights row by row or column by column to achieve the overall display effect. Specifically, the screen will decompose the content to be displayed into multiple rows or columns, and then light up the LED lights of each row or column in a certain order.
Scanning mode classification
The scanning mode of the LED display is mainly divided into static scanning and dynamic scanning:
1. Static scanning:
Working principle: Static scanning is to implement "point-to-point" control from the output of the driver IC to the pixel point. In this mode, each LED pixel is directly connected to a driver IC, and the driver IC directly controls the brightness and color of each pixel according to the input image signal.
Advantages: good display effect, high stability, and small brightness loss.
Disadvantages: relatively high cost because each pixel point needs to be equipped with an independent driver IC.
Application scenarios: Usually used in occasions with high requirements for display effects, such as P16, P20, P25 and other models in outdoor full-color LED display screens.
2. Dynamic scanning:
Working principle: Dynamic scanning is to implement "point-to-column" control from the output of the driver IC to the pixel points. In this mode, the driver IC selects the LED pixels one by one in a certain order, and makes each pixel light up in a short time by time slicing. Due to the visual persistence effect of the human eye, these fast-switching pixels look like they are lit at the same time.
Advantages: Low cost, because the hardware cost can be reduced by sharing the driver IC; at the same time, due to the use of time slicing technology, a higher brightness range and more complex image display effects can be achieved.
Disadvantages: The display effect is relatively poor, and the brightness loss is large; and because of the need to quickly switch pixels, the requirements for the driver IC are also high.
Application scenarios: Widely used in indoor single-color and full-color LED display screens, as well as some outdoor single-color and double-color LED display screens.
Specific implementation of scanning methods
1. Row scanning: In row-by-row scanning, the driver IC will light up the LED lights of each row in order from top to bottom. Only one row of LED lights is lit at a time, and the rest of the rows remain off. When all rows are lit in sequence, the content of the entire screen is fully displayed.
2. Column scanning: Although row scanning is more common, there is also a column scanning method in theory. In this method, the driver IC will light up the LED lights of each column in order from left to right. However, since LED displays are usually organized in rows, column scanning is relatively rare in practical applications.
3. Time-sharing multiplexing technology: In dynamic scanning, in order to increase brightness and reduce costs, time-sharing multiplexing technology is usually used. That is, at the same time, not all LED pixels are lit, but some pixels are turned on in turn by fast switching. This can improve the utilization rate of LEDs and reduce costs, but it will also bring about a certain loss of brightness and compromise in display effects.
Summary
The working principle of the scanning method of LED display screens is to display images and text by lighting up LED lights row by row or column by column. Static scanning and dynamic scanning are the two main scanning modes, each with its own advantages and disadvantages and suitable for different application scenarios.
In actual applications, the scanning method of the LED display screen will also be affected by many factors such as screen type, pixel pitch, and display effect requirements.