As the most expensive and most used component of LED display screen, LED lamp bead plays a leading role in the quality of LED display. Today, let’s introduce to you the eight major influences of LED lamp beads on LED displays.
1. Viewing Angle
The viewing angle of the LED display is determined by the viewing angle of the LED lamp beads. At present, most outdoor LED displays use horizontal viewing angles of 100, elliptical LEDs with vertical viewing angles of 50°, while indoor displays use SMD LEDs with both horizontal and vertical angles of 120°.
Because of its particularity, a circular LED with a viewing angle of 30°is generally sufficient for the display on the highway.
Some high-rise display screens have higher requirements for vertical viewing angles. Viewing angle and brightness are contradictory to each other, and a large viewing angle will inevitably reduce brightness. The choice of perspective needs to be determined according to the specific purpose.
LEDs brightness is an important determinant of display brightness. The higher the brightness of the LED, the greater the margin for the use of current, which is good for saving power and keeping the 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 viewing angle of the display. Generally, a 100-degree LED should be selected to ensure a sufficient viewing angle of the display screen.
For displays with different dot pitches and different viewing distances, a balance should be found in brightness, angle and price.
3. Failure Rate
Since a full-color display screen is composed of tens 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 the display screen.
Generally speaking, according to industry experience, the failure rate from the start of the assembly of the LED display to the 72-hour aging before shipment should be no more than three ten thousandths (referring to the failure caused by the LED lamp beads itself).
4. Antistatic Ability
LED is a semiconductor device, which is sensitive to static electricity and can easily cause static failure. Therefore, the antistatic ability is very important to the life of the display screen.
Generally speaking, the failure voltage of the human body electrostatic mode test of the LED should not be lower than 2000V.
5. Working Life of LED Display
The theoretical life of the LED device is 100,000 hours, which is much longer than the working life of other parts of the LED display.
Therefore, as long as the quality of the LED device is guaranteed, the working current is appropriate, the PCB heat dissipation design is reasonable, and the display screen production process is rigorous, the LED device will be the entire display screen. One of the most durable parts of the machine.
6. Attenuation Characteristics
LED lamp bead can account for 70% of the price of LED displays, so LED light bead can determine the quality of LED displays. China is not only a major producer of LED devices but also a gathering place for LED display manufacturing. The high technical requirements of LED displays are the future development trend.
The requirements of better quality of LED displays are not only about the trend of LED display manufacturers, but also the development of LED display device manufacturers. From the control of LED devices, China will promote China’s transformation from a large LED display manufacturing country to an LED display manufacturing powerhouse.
LED screens will appear brightness decline and display color inconsistency after a long period of work, mainly due to the brightness attenuation of LED devices. The attenuation of LED brightness will reduce the brightness of the entire screen.
The inconsistency of the brightness attenuation of the red, green, and blue LEDs will cause the color of the LED display to be inconsistent, which is the phenomenon that we often say that the display is spent.
High-quality LED devices can well control the brightness attenuation range. According to the standard of 20mA lighting at room temperature for 1000 hours, red attenuation should be less than 2%, blue and green attenuation should be less than 10%, so blue and green LEDs should not use 20mA current when designing the display, preferably only 70% to 80 % Of rated current.
The attenuation characteristics are not only related to the characteristics of the red, green, and blue LEDs, but also the current used, the PCB board heat dissipation design, and the ambient temperature of the display screen.
The size of the LED lamp bead affects the pixel distance of the LED display, that is, the resolution. 5mm oval lights are mainly used for outdoor displays above P16, 3mm oval lights are mainly used for outdoor displays of P12.5, P12, P10, and 3528 SMD LEDs are mainly used for indoor displays of P6 and P8.
2020-type SMD LEDs are mainly used for indoor displays such as P2 and P3.
Under the premise that the dot pitch is constant, the size of the LED device can increase, which can increase the display area and reduce the graininess, but because the black area is reduced, the contrast will be reduced.
On the contrary, the LED light bead size is reduced, the display area is reduced, and the graininess is increased accordingly. The black area is enlarged, thus increasing the contrast.
The full-color display is composed of countless red, green, and blue LEDs. The brightness and wavelength consistency of each color LED determines the brightness consistency, white balance consistency, and chromaticity of the entire display color.
Generally speaking, display manufacturers require device suppliers to provide LEDs with a wavelength range of 5nm and a brightness range of 1:1.3.
These indicators can be achieved by the supplier through a spectroscopy machine. The consistency of voltage is generally not required.
Since 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 the red, green, and blue LEDs will seriously affect the consistency of the white balance at different angles, and directly affect the fidelity of the video color of the display screen.
To achieve the matching consistency of the brightness changes of the red, green, and blue LEDs at different angles, it is necessary to strictly carry out the scientific design in the package lens design and raw material selection, which depends on the technical level of the package supplier.
No matter how good the white balance is in the reverse direction, if the LED angle consistency is not good, the white balance effect of the whole screen at different angles will be bad.
The angle consistency characteristics of LED lamp beads can be measured with a comprehensive LED angle tester, which is particularly important for medium and high-end displays.
In this article, we discuss how the LED lamp bead will influence the final effect of the whole LED display screen. We list 8 factors including viewing angle, brightness, failure rate, antistatic ability, working life, and so forth. It is quite important for users to choose the right LED lamp lights as they actually have a profound impact on the performance of the screen. Sometimes, investing in a LED display board may not be a small decision as the budgets involved can be huge, and that is why we need to pay attention to these details. Just follow our official blog LED FAQ to know more!