What are the effects of LED lamp beads on the LED display? part two

5. Life

The theoretical life of the LED device is 100,000 hours, which is much longer than the working life of other parts of the LED display. Therefore, as long as the quality of the LED device is guaranteed, the working current is appropriate, the PCB heat dissipation design is reasonable, and the display screen production process is rigorous, the LED device will be the entire display screen. One of the most durable parts in the machine.

LED devices account for 70% of the price of LED displays, so LED devices can determine the quality of LED displays. my country is not only a major producer of LED devices, but also a gathering place for custom LED display manufacturing. The high technical requirements of LED displays are the future development trend. The high quality requirements of LED displays are not only about the trend of LED display manufacturers, but also the development of LED display device manufacturers. From the control of LED devices, China will promote China's transformation from a large LED display manufacturing country to an LED display manufacturing powerhouse.

6. Attenuation characteristics

LED display screens will appear brightness decline and display color inconsistency after a long time work, mainly due to the brightness decay of LED devices. The attenuation of LED brightness will reduce the brightness of the entire screen. The inconsistency of the brightness attenuation of the red, green, and blue LEDs will cause the color of the LED display to be inconsistent, which is the phenomenon that we often say that the display is spent. High-quality LED devices can well control the brightness attenuation range. According to the standard of 20mA lighting at room temperature for 1000 hours, red attenuation should be less than 2%, blue and green attenuation should be less than 10%, so blue and green LEDs should not use 20mA current when designing the display, preferably only 70% to 80 % Of rated current.

The attenuation characteristics are not only related to the characteristics of the red, green, and blue LEDs, but also the current used, the PCB board heat dissipation design, and the ambient temperature of the display screen all have an impact on the attenuation.

7. Size

The size of the LED device affects the pixel point distance of the LED display screen, that is, the resolution. 5mm oval lights are mainly used for outdoor displays above P16, 3mm oval lights are mainly used for outdoor displays of P12.5, P12, P10, and 3528 SMD LEDs are mainly used for indoor displays of P6 and P8. 2020-type SMD LEDs are mainly used for indoor displays such as P2 and P3. Under the premise that the dot pitch is constant, the size of the LED device increases, which can increase the display area and reduce the graininess, but because the black area is reduced, the contrast will be reduced; on the contrary, the LED size is reduced, the display area is reduced, and the graininess is increased. , The black area is enlarged, increasing the contrast.

8. Consistency

The full-color display is composed of countless red, green, and blue LEDs. The brightness and wavelength consistency of each color LED determines the brightness consistency, white balance consistency and chromaticity of the entire display. Sex. Generally speaking, display screen manufacturers require device suppliers to provide LEDs with a wavelength range of 5nm and a brightness range of 1:1.3. These indicators can be achieved by the device supplier through the classification of the light-separation machine. The consistency of voltage is generally not required.

Since the LED is angled, the full-color LED display also has angular directionality, that is, when viewed from different angles, its brightness will increase or decrease. In this way, the angle consistency of the red, green, and blue LEDs will seriously affect the consistency of the white balance at different angles, and directly affect the fidelity of the video color of the display screen. To achieve the matching consistency of the brightness changes of the red, green, and blue LEDs at different angles, it is necessary to strictly carry out scientific design in the package lens design and raw material selection, which depends on the technical level of the package supplier. No matter how good the white balance is in the normal direction, if the LED angle is not consistent, the white balance effect of the whole screen at different angles will be bad. The angle consistency characteristics of LED lamp beads can be measured with a comprehensive LED angle tester, which is particularly important for medium and high-end displays.