The viewing angle of LED display screen depends on the viewing angle of LED lamp beads. According to FPC manufacturers, most outdoor displays use elliptical LEDs with a horizontal viewing angle of 100 ° and a vertical viewing angle of 50 °, while indoor displays use patch LEDs with a horizontal and vertical viewing angles of 120 °. Due to its particularity, the display screen on the expressway usually uses a round LED with a 30 ° viewing angle.
LED brightness is an important determinant of display brightness. FPC manufacturers learned that the higher the LED brightness, the greater the margin of current usage, which is good for saving power consumption and maintaining LED stability. LEDs have different angle values. When the chip brightness is set, the smaller the angle, the brighter the LED will be, but the smaller the viewing angle of the display screen will be.
Since the full-color display screen is composed of tens of thousands or even hundreds of thousands of red, green and blue LED pixels, the failure of any color LED will affect the overall visual effect of the display screen.
- Antistatic ability
LED is a semiconductor device, which is sensitive to static electricity and can easily lead to static electricity failure. Therefore, the anti-static ability is crucial to the life of the display screen. In general, the failure voltage of LED in human electrostatic mode test shall not be lower than 2000V.
The theoretical life of LED devices is 100000 hours, which is much longer than the working life of other parts of LED display. As long as the LED devices are of guaranteed quality, the working current is appropriate, the FPC heat dissipation design is reasonable, and the display production process is rigorous, LED devices will be one of the most durable parts of the display machine.
- Attenuation characteristic
After a long time of operation, the LED display screen will appear brightness decline and display color inconsistency, mainly due to the brightness attenuation of LED devices. The attenuation of LED brightness will reduce the brightness of the whole screen. In addition to the characteristics of red, green and blue LEDs, the attenuation characteristics are affected by the current used, the heat dissipation design of the FPC board, and the ambient temperature of the display screen.