How does the LED bead affect the LED display

Time:2018-10-17 Views:318

LED display applications are becoming more and more popular. It can be seen everywhere in the busy streets.In today‘s pervasive display applications, do you know what has the greatest impact on LED display performance?

People who know about the LED display industry know that the biggest impact on the performance of the display is LED beads.The editor of deroncel (www.zhangchongshun.cn) below tells you about eight factors that LED beads affect the LED display.

I. perspective: the perspective of LED display depends on the perspective of LED lamp bead.But most of the outdoor LED display USES horizontal Angle 100 °, vertical Angle of 50 ° elliptical LED, indoor LED display, choose horizontal vertical 120 ° SMD leds.Display on the highway 30 ° Angle is generally selected due to its particularity of round LED is enough.Some tall buildings have LED screens that require a higher vertical Angle of view.Viewing angles and brightness contradict each other, big viewing angles will inevitably reduce brightness.The choice of perspective needs to be determined according to specific purposes.

2. Brightness: the brightness of LED lamp bead is an important determinant of LED display brightness.The higher the brightness of LED lamp bead, the greater the residual current, which is good for saving power and keeping LED stable.Leds have different Angle values. When the brightness of the chip is fixed, the smaller the Angle, the brighter the LED, but the smaller the Angle of the LED display.Generally, 100 degrees of LED should be selected to ensure that the LED screen has sufficient viewing Angle.For screens with different spacing and different viewing distances, a balance should be found in brightness, Angle and price.

Iii. Failure efficiency: as full-color LED display is composed of pixels composed of thousands or even hundreds of thousands of red, green and blue leds, the failure of any color LED will affect the overall visual effect of LED display.Generally speaking, according to industry experience, the failure rate before the LED display assembly starts to aging 72 hours before shipment should be no more than three parts per million (refers to the failure caused by LED beads themselves).

4. Anti-static ability: LED is a semiconductor device, which is sensitive to static electricity and can easily lead to static failure. Therefore, anti-static ability is crucial to the life of LED display screen.In general, the LED human electrostatic mode test failure voltage should not be less than 2000V.

V. life span: the theoretical life of LED device is 100,000 hours, which is much longer than the working life of other parts of LED display screen. Therefore, as long as the quality of LED device is guaranteed, the working current is appropriate, PCB heat dissipation design is reasonable, and the manufacturing process of LED display is rigorous, LED device will be one of the most durable parts in the whole LED display screen.

6. Attenuation characteristics: after a long time of operation, LED display will show a decrease in brightness and color inconsistency, which is mainly caused by the attenuation of LED devices.The attenuation of LED brightness will reduce the brightness of the whole screen.The inconsistency of the brightness attenuation of red, green and blue LED will cause the inconsistency of the color of LED display screen, which is often referred to as the screen screen phenomenon.High quality LED device can control brightness attenuation well.According to the standard of lighting 20mA at 1000 hours room temperature, red attenuation should be less than 2%, and blue and green attenuation should be less than 10%. Therefore, blue and green LED should not use 20mA current as much as possible in the display design, and it is better to use only 70% to 80% of the rated current.

Size: the size of LED device affects the pixel distance of LED display, that is, the resolution.The 5mm oval lamp is mainly used for outdoor LED screens above P16, the 3mm oval lamp is mainly used for outdoor screens of P12.5, P12 and P10, the 3528 patch LED is mainly used for indoor LED screens of P6 and P8, and the 2020 patch LED is mainly used for indoor LED screens like P2 and P3.On the premise that the point spacing remains unchanged, the size of LED device increases, which can increase the display area and reduce the sense of particle. However, as the black area decreases, the contrast is reduced.In contrast, the LED size decreases, reducing the display area, increasing the particle sense, increasing the black area and increasing the contrast.

Consistency: full-color LED display is made up of numerous red, green and blue LED pixels. The brightness and wavelength consistency of each color LED determines the brightness consistency, white balance consistency and chroma consistency of the whole display.As leds are angular, the matching consistency of brightness changes of red, green and blue leds at different angles requires strict scientific design in packaging lens design and raw material selection, which depends on the technical level of packaging suppliers.The Angle consistency characteristic of LED lamp bead can be measured by LED Angle comprehensive tester, which is especially important for medium and high grade display screens.

It is helpful to know the influence factors of LED lamp bead on LED display and select a high quality LED display.