Influence of LED lamp beads on LED display screen
- Viewing angle
The viewing angle of the LED screen depends on the viewing angle of the LED lamp beads. At present, most of the outdoor display screens use a horizontal viewing angle of 100 °; Vertical viewing angle 50 °; The indoor display screen is 120 ° horizontally and vertically; Chip LED. Because of its particularity, the display screen on the expressway is generally 30 °; A circular led with a viewing angle is enough. The display screen on some high buildings requires a high 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.
LED brightness is the decisive factor of display brightness. The higher the brightness of the LED, the larger the margin of the current used, which is beneficial to saving power consumption and maintaining the stability of the LED. LEDs have different angle values. When the chip brightness is set, the smaller the angle, the brighter the LED, but the smaller the viewing angle of the display screen. Generally, 100 degree led shall be selected to ensure sufficient viewing angle of the display screen. For display screens with different dot spacing and different viewing distance, a balance point should be found in brightness, angle and price.
Because the full-color display screen is composed of tens of thousands or even hundreds of thousands of pixels composed of red, green and blue LEDs, the failure of any color LED will affect the overall visual effect of the display screen. Generally speaking, according to industry experience, the failure rate from the beginning of LED screen assembly to 72 hours before shipment should not be higher than 3 / 10000 (refers to the failure caused by the LED lamp beads themselves).
- Antistatic capacity
LED is a semiconductor device, which is sensitive to static electricity and easy to cause static failure, so the anti-static ability is crucial to the life of the display screen. Generally speaking, the human body electrostatic mode test failure voltage of LED should not be lower than 2000V.
- Life span
The theoretical life of LED devices is 100000 hours, which is much longer than the working life of other components of LED screen. Therefore, as long as the quality of LED devices is guaranteed, the working current is appropriate, the PCB heat dissipation design is reasonable, and the display screen production process is rigorous, LED devices are one of the durable components of the display screen.
LED devices account for 70% of the price of LED screen, so LED devices can determine the quality of LED screen. China is not only a major producer of LED devices, but also a gathering place of LED screen manufacturing. The high-tech requirement of LED screen is the future development trend. The high-quality requirement of LED screen is not only about the trend of LED screen manufacturers, but also about the development of LED screen device manufacturers.
- Attenuation characteristics
The LED screen will appear the phenomenon of brightness decline and display screen color inconsistency after working for a long time, which is mainly caused by the brightness attenuation of LED devices. The attenuation of LED brightness will reduce the brightness of the whole display screen. The inconsistency of the brightness attenuation of red, green and blue LEDs will cause the inconsistency of LED screen colors, which is the phenomenon we often say that the display screen is spent. High quality LED devices can well control the brightness attenuation amplitude. According to the standard of lighting 20mA at room temperature for 1000 hours, the red attenuation should be less than 2%, and the blue and green attenuation should be less than 10%. Therefore, the blue and green LEDs should not use 20mA current in the design of the display screen, and only use 70% to 80% of the rated current.
In addition to the characteristics of red, green and blue LEDs, the attenuation characteristics are affected by the current used, the heat dissipation design of PCB board, and the ambient temperature of display screen.
The size of the LED device affects the pixel distance of the viewing angle, that is, the resolution. The 5mm elliptical lamp is mainly used for outdoor display above p16, the 3mm elliptical lamp is mainly used for outdoor display of p12.5, p12 and P10, the 3528 patch LED is mainly used for indoor display of P6 and P8, and the 5050 patch LED is mainly used for semi outdoor display such as p16 and p12.5. Under the premise of constant dot spacing, the LED device size increases, which can increase the display area and reduce the sense of graininess, but the contrast will be reduced due to the reduction of the black area; On the contrary, the LED size decreases, reducing the display area, increasing the sense of graininess, increasing the black area, and increasing the contrast.
The full-color display screen is composed of pixels composed of countless red, green and blue LED. The consistency of brightness and wavelength of each color LED determines the brightness consistency, white balance consistency and chromaticity consistency of the whole display screen. Generally speaking, the display screen manufacturer requires the device supplier to provide LED with a wavelength range of 5nm and a brightness range of 1:1.3. These indicators can be graded by the device supplier through a spectroscope. Generally, voltage consistency is not required.
OBVIOUS is one of the leading Manufacturer of outdoor LED screen, LED signage, LED poster, LED floor tiles in China. Whether indoor led screen, outdoor led screen or dance floor led screen, transparent led screen, poster led screen, curved led screen, all have high cost performance, quality and service is our advantage.OBVIOUS is also a high-tech enterprise integrating R & D, manufacturing and sales.certificates are complete.
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