LED display (LED panel) is a display screen that controls semiconductor light-emitting diodes to display various information such as text, graphics, images, animations, quotes, videos, and video signals. Through the appropriate connection of the light-emitting diode chips (including series and parallel) and the appropriate optical structure. It can form the luminous segment or luminous point of a light-emitting display. From these luminous segments or luminous dots, it can be composed of digital tubes, symbol tubes, meter tubes, matrix tubes, level display tubes, and so on. Generally, the digital tube, the symbol tube, and the rice tube are collectively referred to as the stroke display, and the stroke display and the matrix tube are collectively referred to as the character display.