Wednesday, June 1, 2022 at 9:01:27 AM GMT+00:00
5. Antistatic ability
6. Attenuation characteristic
LED beads are the most important part of LED display. First of all, LED is the most commonly used core equipment of full-color screen, and thousands to tens of thousands of LEDs are used per square meter. Secondly, LED is the main body determining the performance of full screen optical display, which directly affects the audience's evaluation of the display.Teach you how to distinguish between LED display lamp beads.
LED brightness is an important determinant of display brightness. The higher the LED brightness, the greater the margin of current usage, which is beneficial to 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. Generally, 100 degree LED shall be selected to ensure adequate viewing angle of the display screen. For displays with different point spacing and viewing distance, a balance point should be found in brightness, angle and price.
The viewing angle of LED display screen depends on the viewing angle of LED lamp beads. At present, most outdoor LED displays use elliptical LEDs with a horizontal viewing angle of 100 ° and a vertical viewing angle of 50 °, while indoor LED 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. The display screen on some tall buildings has high requirements for vertical viewing angle. Angle of view and brightness are contradictory, and large angle of view will inevitably reduce brightness. The choice of perspective needs to be determined according to the specific purpose.
Since the full-color LED display screen is composed of thousands of groups of red, green and blue LED pixels, the failure of any color LED will affect the overall visual viewing effect of the display screen. Therefore, generally speaking, the failure rate of LED display screen shall not be higher than two thousandths within three days from assembly to shipment.
LED display screen is composed of red, green and blue pixels. The brightness and wavelength consistency of each color LED will determine the brightness and consistency of the entire display screen. Generally speaking, the device supplier required by the LED display manufacturer shall provide LED with a wavelength range of 4nm, and these indicators can be achieved by the device supplier through the light splitting and color separation machine.
As LED products are semiconductor devices, they are extremely sensitive to static electricity. Because of their sensitivity, static electricity failure will occur. Therefore, the static electricity capability is very important to the life of the display screen.
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. Inconsistent brightness attenuation amplitude of red, green and blue LEDs will lead to inconsistent color of LED display, which is often referred to as the phenomenon of spent display. High quality LED devices can well control the brightness attenuation. The red attenuation shall be less than 2% and the blue and green attenuation shall be less than 10% according to the standard of 20mA lit at room temperature for 1000 hours. Therefore, the blue and green LED shall not use 20mA current as much as possible in the design of the display screen, and it is better to use only 70% to 80% of the rated current.
The general life of LED on the display screen is 100000 hours or more, so when the life is long or even longer, we should ensure the quality of LED devices, the appropriate working current, the reasonable PCB heat dissipation design, and rigorous production. LED devices will be an important point for the display screen to glow.Do you want to know how to prolong the life of LED display?
The size of the LED device affects the pixel distance of the LED display, that is, the resolution. The 5mm oval lamp is mainly used for outdoor displays above P16, the 3mm oval lamp is mainly used for outdoor displays of P12.5, P12 and P10, the 3528 patch LED is mainly used for indoor displays of P6 and P8, and the 2020 patch LED is mainly used for indoor displays of P2 and P3. On the premise that the distance between dots is unchanged, the increase of LED device size can increase the display area and reduce the graininess, but the reduction of black area will reduce the contrast; On the contrary, the LED size decreases, reducing the display area, increasing the graininess, increasing the black area, and increasing the contrast.