Five quality parameters affecting LED full-color display

1. Failure Rate Because the full-color display consists of tens of thousands or even hundreds of thousands of pixels consisting of red, green and blue LEDs, the failure of any color LED will affect the overall visual effect of the display. In general, according to industry experience, the failure rate of the LED display before it is assembled to aging 72 hours before shipment should not be higher than three ten-thousandths (the failure caused by the LED device itself).

2, anti-static ability LED semiconductor devices, sensitive to static electricity, easily lead to electrostatic failure, so the anti-static ability of the display screen is critical to the life. In general, LED body static mode test failure voltage should not be less than 2000V.

3. Attenuation characteristics Red, green, and blue LEDs all have a feature that the brightness decreases as the operating time increases. The quality of LED chips, the quality of auxiliary materials and the level of packaging technology determine the LED decay speed. In general, after 1000 hours and 20 mA ambient temperature lighting test, red LED attenuation should be less than 10%. Blue and green LED attenuation should be less than 15%. Consistency of red, green, and blue attenuation for full-color LED display future white The balance has a great impact, which in turn affects the display fidelity of the display.

4, brightness LED brightness is an important determinant of display brightness. The higher the brightness of the LED, the greater the remaining amount of current used, which is good for saving power consumption and maintaining LED stability. The LED has different angle values. When the chip brightness is fixed, the smaller the angle is, the brighter the LED is, but the smaller the viewing angle of the display screen is. Generally, 100-degree LEDs should be selected to ensure that the display has a sufficient viewing angle. For display screens with different dot pitches and different line of sight, a balance should be found in brightness, angle, and price.

5. Consistency The full-color display is composed of numerous pixels composed of red, green and blue LEDs. The consistency of the brightness and wavelength of each color LED determines the brightness uniformity, white balance consistency and color of the entire display screen. Degree of consistency. In general, display manufacturers require device vendors to provide LEDs with a 5nm wavelength range and brightness range. These specifications can be graded by a device supplier through a spectrophotometric separator. Voltage uniformity is generally not a requirement.

Because the LED is angled, the full-color LED display also has angular directionality. That is, when viewing at different angles, the brightness will be increased or decreased. The consistency of the LED angles of the three colors red, green, and blue will seriously affect the difference. The consistency of the angle white balance directly affects the fidelity of the display video color. To achieve consistent matching of brightness changes at different angles of red, green, and blue LEDs, it is necessary to strictly design the package lens design and raw material selection, depending on the packaging vendor's technical level. The display with even white balance in the normal direction, if the LED angle consistency is not good, the white balance effect of the entire screen at different angles will be poor. The LED device's angle consistency characteristics can be measured by the LED angle comprehensive tester. High-end display is especially important.