What is the Impact of LED Lamp Bear on the LED Display?

1. Viewing angle

The viewing angle of the LED display is determined by the viewing angle of the LED lamp. At present, most of the outdoor display screens use an elliptical LED lamp which has a 100° horizontal viewing angle and vertical viewing angle of 50°. The indoor LED display choose to use a 120° horizontal and vertical LED lamp. The display on the highway always use round LED lamp with a 30° viewing angle due to its particularity. Some high buildings require a higher vertical viewing angle. The angle of view and the brightness are contradictory, and a large angle of view necessarily reduces the brightness. The choice of viewing angle needs to be determined based on the specific application.


2. Brightness

LED brightness is an important determinant of display brightness. The higher the brightness of the LED, the larger the margin of current used, which is beneficial for saving power and keeping the LED stable. LEDs have different angle values. In the case where the brightness of the chip is determined, the smaller the angle, the brighter the LED, but the smaller the viewing angle of the display. Generally, we should choose a 100 degree LED to ensure a sufficient viewing angle of the display. For displays with different dot pitches and different line of sight, a balance should be found in brightness, angle and price.


3. Failure Rate

Since the full-color display 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. In general, according to industry experience, the failure rate should be no more than three ten thousandth before the LED display starts to assemble to aging 72 hours before shipment (refer to the failure caused by the LED lamp itself).


4. Anti-static ability

LEDs are semiconductor devices that are sensitive to static electricity and are highly susceptible to electrostatic discharge. Therefore, anti-static capability is critical to the life of the display. In general, the LED's human body static mode test failure voltage should not be lower than 2000V.


5. Useful life

The theoretical life of LED devices is 100,000 hours, which is much longer than the working life of other components of LED display. Therefore, as long as the LED device quality is guaranteed, the working current is suitable, the PCB heat dissipation design is reasonable, and the display production process is rigorous, the LED device will be one of the most durable parts in the display screen panel.


6. Attenuation characteristics

When the LED display is operated for a long time, the brightness will drop and the color of the display will be inconsistent, mainly due to the brightness degradation of the LED device. Attenuation of the LED brightness can cause the brightness of the overall display to decrease. Inconsistent brightness attenuation of red, green and blue LEDs will cause inconsistencies in the color of the LED display, which is what we often call the display blurred. High-quality LED devices provide excellent control of the brightness attenuation. According to 1000 hours of normal temperature lighting 20mA standard, 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 using 70% to 80% % rated current. In addition to the characteristics of the red, green and blue LEDs, the attenuation characteristics are affected by the current, the heat dissipation design of the PCB, and the ambient temperature around the display.


7. Size

The size of the LED device affects the pixel point distance of the LED display, i.e. the resolution. The 5mm elliptical lamp is mainly used for outdoor display above P16, the 3mm elliptical lamp is mainly used for outdoor LED display of P12.5, P12 and P10, and the 3528 type SMD LED is mainly used for indoor LED display of P6 and P8. The 2020 SMD LED is mainly used for indoor LED displays such as P2 and P3. Under the premise of constant dot pitch, the LED device size increases, which can increase the display area and reduce the graininess. However, due to the reduction of the black area, the contrast will be reduced. On the contrary, the LED size is reduced, the display area is reduced, and the graininess is increased. The black area increases and the contrast is increased.


8. Consistency

The full-color display is composed of countless red, green and blue LEDs. The brightness and wavelength consistency of each color LED determine the brightness consistency, white balance consistency and chromaticity uniformity of the entire LED display. In general, LED display manufacturers require LED lamp vendors to provide LEDs with a wavelength range of 5 nm and a brightness range of 1:1.3. These specifications can be achieved by LED lamp suppliers through a spectral color separation machine. The consistency of the voltage is generally not required.

Since the LEDs are angled, the full color LED display also has angular orientation, that is, the brightness is increased or decreased when viewed at different angles. In this way, the angular consistency of the red, green, and blue LEDs will seriously affect the consistency of white balance at different angles, directly affecting the fidelity of the display video color. In order to achieve the consistency of the brightness changes of the red, green and blue LEDs at different angles, it is necessary to strictly carry out scientific design on the packaging lens design and raw material selection, it depends on the technical level of the LED chip packaging supplier. In the normal direction, the white balance is good. If the angle of the LED is not consistent, the white balance effect at different angles of the whole screen will be bad. The angle consistency of the LED lamp can be measured by the LED angle comprehensive tester, which is especially important for medium and high level LED display wall.