Eight aspects of the influence of LED light beads on LED display screen
the perspective of LED display screen depends on the perspective of LED light beads. At present, most outdoor displays use horizontal viewing angle of 100 ° Vertical viewing angle 50 °; Oval LED, indoor display screen is 120 ° horizontal and vertical; Patch LED of. Because of its particularity, the display screen on expressway is generally 30 °; The circular LED of perspective is enough to realize the transformation of B2B from information mode to transaction mode. The display screen on some high-rise buildings has high requirements for vertical viewing angle. The angle of view and brightness are contradictory, and a large angle of view will inevitably reduce the brightness. The choice of perspective needs to be determined according to the specific purpose
2, brightness
led brightness is an important determinant of display brightness. The higher the brightness of the LED, the greater the margin of the current used, which is good for saving power consumption and maintaining the stability of the LED. LEDs have different angle values. When the brightness of the chip is set, the smaller the angle, the brighter the LED, but the smaller the viewing angle of the display screen. Generally, 100 degree LED should be selected to ensure sufficient viewing angle of the display screen. For display screens with different point spacing and different viewing distance, the product quality and variety should be constantly improved, and a balance should be found in brightness, angle and price
3. Inefficiency
because the full-color display screen is composed of tens of thousands or even hundreds of thousands of pixel points 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 of LED display screen 72 hours before shipment should not be higher than 3/10000 (referring to the failure caused by the LED bead itself)
4. Antistatic ability
led is a semiconductor device, which is sensitive to static electricity and easily leads to static failure. Therefore, antistatic ability is very important 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, and then press the calibration key to confirm
5. Service life
the theoretical service life of LED devices is 100000 hours, which is much longer than the working life of other components of LED display screen. Therefore, as long as the quality of LED devices is guaranteed, the working current is appropriate, the heat dissipation design of PCB is reasonable, and the production process of display screen is rigorous, LED devices will be one of the most durable components in the whole display screen
led devices account for 70% of the price of display screen that led hopes to jointly promote the sustainable and healthy development of polyurethane industry. Therefore, LED devices can determine the quality of LED display screen. China is not only a major producer of LED devices, but also a gathering place for the manufacture of LED display screens. The high-tech requirements of LED display screen are the development trend in the future. The high-quality requirements of LED display screen are not only about the trend of LED display screen manufacturers, but also involve the development of LED display device manufacturers. From the control of LED devices, China will promote the transformation from a large LED display manufacturing country to a powerful LED display manufacturing country
6. Attenuation characteristics
led display screen will appear the phenomenon of brightness decline and inconsistent display screen color after long-time operation, 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 inconsistent brightness attenuation of red, green and blue LED will cause the inconsistent color of LED display screen, which is the phenomenon we often say that the display screen is spent. High quality LED devices can well control the brightness attenuation. According to the standard of 20mA lighting 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, try not to use 20mA current in the design of blue and green LEDs in the display screen, and it is best to use only 70% to 80% of the rated current
in addition to the characteristics of red, green and blue LEDs, the attenuation is affected by the current used, the heat dissipation design of PCB board, and the ambient temperature of display screen
7. Size
the size of LED devices affects the pixel distance of LED display screen, that is, the resolution. 5mm oval lamp is mainly used for outdoor displays above p16, 3mm oval lamp is mainly used for outdoor displays of p12.5, p12 and P10, 3528 patch LED is mainly used for indoor displays of P6 and P8, and 2020 patch LED is mainly used for indoor displays such as P2 and P3. On the premise of constant point spacing, the size of LED device increases, which can increase the display area and reduce the sense of granularity. However, due to the reduction of black area, the contrast will be reduced; On the contrary, the LED size is reduced, the display area is reduced, the graininess is increased, the black area is increased, and the contrast is increased
8, consistency
the full-color display screen is composed of countless red, green and blue LED pixels. The brightness and wavelength consistency of each color LED determines the brightness consistency, white balance consistency and chromaticity consistency of the whole display screen. Generally speaking, the display manufacturer requires the device supplier 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 light and color separation machine. Voltage consistency is generally not required
because 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 red, green and blue LEDs will seriously affect the consistency of white balance at different angles, and directly affect the fidelity of video color on the display screen. To achieve the matching consistency of the brightness changes of red, green and blue LEDs at different angles, we need to strictly carry out scientific design in the design of packaging lens and the selection of raw materials, which depends on the technical level of packaging suppliers. The display screen with the best white balance in the normal direction, if the angle consistency of the LED is not good, the white balance effect of the whole screen at different angles will be bad. The angle consistency characteristics of LED light beads can be measured by LED angle comprehensive tester, which is particularly important for medium and high-end display screens
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