Key performance index of led (light-emitting ) Display

- Oct 11, 2019-

  1. Antistatic ability led is a semiconductor device, which is sensitive to static electricity and can easily lead to electrostatic failure, so antistatic ability is very important to the life of led display screen. Generally speaking, the failure voltage of led in human electrostatic mode test should not be lower than 2000V.

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  2. After working for a long time, the brightness of led display screen will decrease and the color of the display screen will not be consistent, which is mainly caused by the brightness attenuation of led devices. The attenuation of led brightness will lead to the decrease of the whole screen brightness of led display screen. The inconsistency of brightness attenuation of red, green and blue led will cause the color inconsistency of led display screen, which is what we often call the phenomenon of led display screen. The high quality led device can control the brightness attenuation amplitude very well. According to the 20ma standard of 1000 hours at room temperature, the red attenuation should be less than 2%, the blue and green attenuation should be less than 10%, so the blue and green led should not use 20ma current as far as possible in the display screen design, and it is best to use only 70% to 80% rated current. Except for the characteristics of red, green and blue led, the attenuation characteristics are affected by the current, the heat dissipation design of pcb board and the ambient temperature of led display screen. 

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3, the brightness of the brightness lamp is an important determinant of the brightness of the led (light-emitting diode) display screen. The higher the light-emitting diode (led) brightness, the larger the margin of the use current, the power consumption is saved, and the light-emitting diode is kept stable. The light-emitting diode (led) has different angle values, and in the case where the brightness of the chip is determined, the smaller the angle, the brighter the light-emitting diode (led), but the smaller the viewing angle of the display screen. A light-emitting diode (led) of 100 degrees should generally be selected to ensure a sufficient viewing angle of the led display. A balance point should be found on the brightness, angle and price for light-emitting diode (led) displays with different spacing and different line of sight. 

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4, the angle of the light-emitting diode (led) lamp bead determines the viewing angle of the led (light-emitting diode) display At present, the outdoor led (light-emitting diode) display screen mostly adopts an elliptical patch led (light-emitting diode) lamp bead with a horizontal visual angle of 120 DEG and a vertical angle of 70 DEG, and the indoor light-emitting diode (led) display screen also selects a patch light-emitting diode (led) lamp bead with a horizontal vertical angle of 120 DEG. The light-emitting diode (led) display screen on the expressway is generally a circular light-emitting diode (led) with a viewing angle of 30 degrees due to its particularity. Some high-level led displays require a higher vertical viewing angle. The angle of view and the brightness are mutually contradictory, and the large viewing angle will inevitably reduce the brightness. The selection of the viewing angle needs to be determined according to the specific use.