1, perspective

LED display angle depends on the LED lamp beads perspective. At present, most outdoor displays use horizontal viewing angle of 100 °; vertical viewing angle of 50 °; oval LED, the indoor display screen is selected horizontal and vertical are 120 °; On the highway display due to its particularity generally use 30 °; angle of the round LED is enough. Some tall buildings have high vertical viewing angles. Visual angle and brightness mutually contradictory, big angle of view will inevitably reduce the brightness. The choice of perspective needs to be based on the specific purpose.

2, brightness

LED brightness is an important determinant of display brightness. The higher the LED brightness, the greater the current margin, to save power and maintain LED stability is good. LED has different angle values, the chip brightness has been set, the smaller the angle, the brighter LED, but the smaller the viewing angle of the display. General should choose 100 LED to ensure that the screen enough perspective. For different point spacing and different line of sight of the display, brightness, angle and price should find a balance point.

3, the failure rate

As the full-color display by the tens of thousands or even hundreds of thousands of red, green and blue composed of three kinds of LED pixels, the failure of any color LED will affect the overall visual display screen. In general, according to industry experience, the failure rate before LED display starts assembling to 72 hours aging should not be higher than three ten thousandths (referring to the failure caused by LED lamp bead itself).

4, anti-static ability

LED is a semiconductor device, sensitive to static electricity, can easily lead to static electricity failure, so anti-static ability of the life of the display is crucial. In general, LED human body static mode test failure voltage should not be less than 2000V.

5, life expectancy

LED device theoretical life of 100,000 hours, much larger than the LED display of other parts of the working life, so long as the LED device quality assurance, the current work properly, PCB cooling design is reasonable, the display production process is rigorous, LED devices will be the whole display One of the most durable parts in the machine.

LED devices accounted for 70% of the proportion of the price of LED display, LED devices that can determine the pros and cons of LED display quality. Our country is the production of LED devices, but also the LED display system to do the gathering place. LED display of high-tech requirements is the future trend of development, LED display of high quality requirements, not only on the LED display manufacturers to the trend, but also implicated LED display manufacturers. Checked from the LED devices to promote China from the LED display manufacturing power to the LED display manufacturing power shift.

6, attenuation characteristics

LED display will appear after working for a long time brightness and display color inconsistencies, mainly due to the brightness of the LED device attenuation caused. Attenuating the brightness of the LED can cause the entire screen brightness to decrease. Red, green and blue LED brightness attenuation inconsistencies will result in inconsistencies in the color LED display, that is, we often say that the phenomenon of the display spent. High-quality LED devices can well control the brightness attenuation range. According to 1000 hours normal temperature lighting 20mA standard, red attenuation should be less than 2%, blue, green attenuation should be less than 10%, so blue, green LED display screen design as much as possible not to use 20mA current, preferably only 70% to 80 % Of the rated current.

In addition to decay characteristics with the red, green and blue LED itself related to the characteristics, the use of current, PCB board cooling design, the use of display temperature, etc. have an impact on the attenuation.

7, size

LED device size affects the LED display pixel distance, that is, resolution. 5mm oval lamp is mainly used for outdoor display above P16, 3mm oval lamp is mainly used for P12.5, P12, P10 outdoor display, 3528 SMD LED is mainly used for P6, P8 indoor display, 2020 type SMD LED is mainly used for P2, P3 and other indoor display. In the same point spacing under the premise of LED device size increases, can increase the display area, reduce the sense of grainy, but due to the reduction of the black area, will reduce the contrast; on the contrary, LED size decreases, reducing the display area, increased graininess , Black area increases, increased contrast.

8, consistency

Full-color display is composed of countless red, green and blue LED pixels composed of each color LED brightness, wavelength consistency determines the consistency of the entire screen brightness, white balance consistency, color consistency Sex. In general, display manufacturers require device suppliers to provide LEDs in the 5nm wavelength range and 1: 1.3 brightness range, which can be graded by the device supplier through a spectrophotometer. Voltage consistency is generally not required.