What are the effects of LED lamp beads on LED display screens?

Under the condition of rapid development, LED screens are more and more widely used. In LED display, the most important thing is LED lamp. The quality of the LED lamp affects the quality of the LED display. And it's the most used key component in the whole screen. It's also the main thing that determines the optical display performance of the entire screen, which directly affects the audience's evaluation of the screen. Now this artical will let you know more about LED LAMP BEAD.

What are the effects of LED lamp beads on LED display screens?

1. Viewing angle

The viewing angle of an LED display screen is determined by the viewing angle of the LED lamp beads. Currently, outdoor LED display screens mostly use elliptical LEDs with a horizontal viewing angle of 100° and a vertical viewing angle of 50°. Indoor led display screens use surface-mounted LEDs with a horizontal and vertical viewing angle of 120°. Led Display screens on highways generally use circular LEDs with a viewing angle of 30° due to their special characteristics. Some LED display screens on high-rise buildings have higher requirements for vertical viewing angles. The choice of viewing angle needs to be determined based on specific use.

2. Brightness

LED brightness is an important factor in determining the brightness of the LED display screen. The higher the LED brightness, the greater the remaining current for power-saving and stabilizing the LED. LEDs have different angle values. Given that the LED lamp bead brightness is fixed, the smaller the angle, the brighter the LED, but the viewing angle of the LED display screen will be smaller. Generally, 100-degree LEDs should be selected to ensure a sufficient viewing angle for the LED display screen. For LED display screens with different dot pitch and viewing distances, a balance point should be found in terms of brightness, angle, and price.

3. Failure rate

Full-color LED display screens consist of tens 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 LED display screen. Generally, based on industry experience, the failure rate caused by LED lamp bead failure before the led display screen is assembled and shipped should not exceed 0.03%.

4. Electrostatic protection

LEDs are semiconductor devices that are sensitive to static electricity and can easily cause static electricity failure. Therefore, anti-static ability is crucial for the lifespan of the LED display screen. Generally, the failure voltage of LED's human body electrostatic mode test should not be lower than 2000V.

5. Lifespan

The theoretical lifespan of LED lamp bead is 100,000 hours, far longer than that of other components in LED display screens. Therefore, as long as the quality of LED lamp bead is guaranteed, the operating current is appropriate, the PCB heat dissipation design is reasonable, and the production process of the display screen is rigorous, LED componets will be one of the most durable components in the LED display screen. LED components account for 70% of the price of LED display screens, so the quality of LED components can determine the quality of LED display screens.

6. Decay characteristics

After long-term operation, the LED display screen may experience a decrease in brightness and inconsistent colors, mainly caused by the decay of LED components brightness. The decay of LED brightness will cause the overall brightness of the led display screen to decrease. The inconsistency in the brightness decay of red, green, and blue LEDs will cause the colors on the LED display screen to be inconsistent, which is commonly known as "screen flower." High-quality LED components can well control the brightness decay. Based on the standard of being lit at 20mA for 1000 hours at room temperature, the decay of red should be less than 2%, and the decay of blue and green should be less than 10%. Therefore, blue and green LEDs are more likely to experience brightness decay. The high-quality LED components can effectively avoid the problem of brightness decay and color inconsistency. It promotes China's transition from a manufacturer of LED display screens to a strong country in the production of LED display screens by controlling the quality of LED components.

7. Size

The size of LED devices affects the pixel spacing and resolution of LED display screens. Elliptical lamps with a diameter of 5mm are mainly used for outdoor displays with a pixel pitch of P16 or larger, while those with a diameter of 3mm are used for outdoor displays with a pixel pitch of P12.5, P12, and P10. Surface-mounted LEDs of the 3528 type are mainly used for indoor displays with a pixel pitch of P6 and P8, while those of the 2020 type are mainly used for indoor displays with a pixel pitch of P2 and P3. Increasing the size of LED devices can increase the display area and reduce the graininess, but it can also decrease the contrast due to the reduced black area. On the other hand, reducing the size of LEDs can increase the graininess and black area, and hence increase the contrast, but it can also decrease the display area.

8. Consistency

Full-color LED displays are made up of countless red, green, and blue LEDs that form pixels. The consistency of the brightness and wavelength of each color LED determines the consistency of the entire display's brightness, white balance, and chromaticity. LED Display manufacturers generally require LED suppliers to provide LEDs with a wavelength range of 5nm and a brightness range of 1:1.3. These indicators can be achieved through grading using a spectrophotometer by the LED supplier. Voltage consistency is generally not required.

Since LEDs have angles, full-color LED displays also have angular directionality. Therefore, the brightness of the display will increase or decrease when viewed from different angles. The angular consistency of the red, green, and blue LEDs will seriously affect the white balance consistency at different angles, directly affecting the color fidelity of the display screen's video. To achieve matching consistency of the brightness change of the three color LEDs at different angles, strict scientific design is required in the packaging lens design and raw material selection. This depends on the technical level of the packaging supplier. Even if the white balance of the display is good in the normal direction, if the angular consistency of the LEDs is poor, the white balance effect at different angles will be poor. The angular consistency of the LED chips can be measured using an LED angle comprehensive tester, which is particularly important for medium- and high-end displays.

What are the main LED packaging manufacturers for LED display screens in China?

From now on, on Led display market have many different led lamp brands. Here let me introduce to you the different quality level between different led brands. Generally, in the market in Shenzhen, China, for led display are Nationstar, kinglight, Kn-light, Hongsheng, Mulinsen.

By the way, international famous top quality level led have Cree (Made in the USA) and Nichia ( Made in Japan). The stability and performance of CREE/ Nichia are the best. While the cost of single led lamp of Cree and Nichia price is 3-5 times than Nationstar. And square meter price will heigher 5-6 times. At the currently, there are less clients use the two brands. Only 3-5% very  big important projects will choose Cree and Nichia.

We can define 3 different quality level for frequent led which made in China:

The top level: Nationstar

   For customers who have quality requirements, 95% will choose to use the Nationstar LED, because the Nationstar LEDs also have different quality levels, such as high-bright gold wire, gold wire, and copper wire.

The middle level: kinglight/Knlight

   The price will be lower than the Nationstar. For some projects, if the budget is really cannot meet the demand, then Kinglight/Knlight LED will be the first option. The failure rate of the Kinglight LEDs is good, and generally speaking, there will be a small problem in every two or three years.

The third level: Hongsheng/mulinsen

The Hongsheng/mulinsen LEDs are mostly suppliers to some factories with a low wholesale price of the LED modules. Which are most popular in Wholesale market, especial in the Asia market. In recent two years, the stability is also goods, no have big problem in 2 years.

What's the Difference Between Black LED Screens and White LED Screens?

Some customers have expressed curiosity about black LED screens, as most screens on the market are white LED screens. In fact, black LED screens use different packaging technology from white LED screens. But what exactly is the difference between them?

1. White LED lamp bead:

LEDs are assembled from plastic brackets and light-emitting chips. In the early days, the light-emitting chips had low brightness, so engineers made the plastic brackets white and bowl-shaped to enhance focusing reflection, which ensured that the chips with low brightness achieved a brighter effect. However, white LEDs also have some drawbacks. When displaying black, gray, and deep green colors, the glowing diodes of its white base color also participate in the colors displayed on the electronic screen, resulting in color distortion (inability to display black, gray, deep green, etc.). Engineers compensate for the lack of chip brightness by sacrificing color expression.

2. Black LED lamp bead:

Nowadays, as LED light-emitting brightness is increasing, LED tubes no longer need to be made white to achieve satisfactory results. In order to meet people's requirements for image realism, some manufacturers have begun to develop black LED screens to improve the contrast of LED screens. Black LED screens have higher contrast and a more uniform base color for the entire screen.

In conclusion, black LED lamp bead use plastic brackets that are packaged with black LEDs to create a display. With increasing demands for displays and the constant advancement of LED technology, black lamp bead are expected to become one of the mainstream products on the market.