How Omaha identifies the pros and cons of LED display beads

First, look at the solder joints. LED strips produced by regular LED strip manufacturers are produced using SMT patch technology, solder paste and reflow soldering process

Second, look at FPC quality. FPC is divided into copper and rolled copper. The copper foil of the copper-clad board is protruding. If you look closely, you can see from the connection between the pad and the FPC.

Third, look at the cleanliness of the surface of the LED strip. If the LED light strip produced by the SMT process is used, the surface cleanliness is very good, and no impurities and stains can be seen.

4. Look at the chips and production process of LED lights. You can't tell the difference with your eyes. You need to use aging equipment and testing equipment. If you put the LEDs of several manufacturers on the aging instrument, use high current for 24 hours or longer. Time, you go to measure the LED brightness of a few manufacturers, and see that the LED luminous intensity attenuation is the smallest, and the quality with the smallest attenuation is the best.

What are the effects of Omaha LED lamp beads on LED displays

1. Perspective

The viewing angle of the LED display depends on the viewing angle of the LED lamp beads. At present, most outdoor display screens use horizontal viewing angles of 100 °; vertical viewing angles of 50 °; elliptical LEDs, and indoor display screens use patch LEDs that are both 120 ° horizontal and vertical. The display on the highway is generally selected at 30 ° due to its particularity; a circular LED with a viewing angle is sufficient. Some high-rise displays require higher vertical viewing angles. Viewing angle and brightness contradict each other, and large viewing angle will inevitably reduce brightness. The choice of perspective 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 greater the margin of the current used, which is beneficial to saving power consumption and keeping the LED stable. LEDs have different angle values. When the chip brightness 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. For displays with different dot pitches and different viewing distances, a balance point should be found in brightness, angle and price.

3. Failure rate

Since a full-color display consists of tens or even hundreds of thousands of pixels of three groups of red, green and blue LEDs, the failure of any color LED will affect the overall visual effect of the display. Generally speaking, according to industry experience, the failure rate of the LED display before it is assembled to the aging 72 hours before shipment should be no more than three ten thousandths (referring to the failure caused by the LED lamp beads themselves).

4.Antistatic ability

LEDs are semiconductor devices that are sensitive to static electricity and can easily cause static electricity failure. Therefore, the antistatic ability is very important to the life of the display. Generally speaking, the failure voltage of the human body's static mode test of LED should not be lower than 2000V.

5, life

The theoretical life of LED devices is 100,000 hours, which is much longer than the working life of other parts of LED display screens. As long as the LED device quality is guaranteed, the working current is appropriate, the PCB heat dissipation design is reasonable, and the display screen production process is rigorous, LED devices will be the entire display screen. One of the most durable parts in the machine.

LED devices account for 70% of the price of LED displays, so LED devices 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 screens. The high-tech requirements of LED displays are the future development trend. The high-quality requirements 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's transition from a major LED display manufacturing country to a strong LED display manufacturing country has been promoted.

6, attenuation characteristics

After a long time working, the LED display will have a decrease in brightness and inconsistent display colors, which is mainly caused by the attenuation of the brightness of the LED device. The attenuation of LED brightness will cause the brightness of the entire display screen to decrease. The inconsistencies in the brightness attenuation of the red, green, and blue LEDs will cause the inconsistencies in the color of the LED display, which is what we often say is the display spent. High-quality LED devices can well control the brightness attenuation. According to the standard of lighting 20mA at 1000 hours of normal temperature, the attenuation of red should be less than 2%, and the attenuation of blue and green should be less than 10%. Therefore, blue and green LEDs should not use 20mA current when designing the display. % Of rated current.

In addition to the attenuation characteristics related to the characteristics of the red, green, and blue LEDs, the use of current, PCB board heat dissipation design, and display screen ambient temperature all affect the attenuation.

7, size

The size of the LED device affects the pixel distance of the LED display, that is, the resolution. 5mm oval light is mainly used for outdoor display above P16, 3mm oval light is mainly used for outdoor display of P12.5, P12, P10, 3528 type SMD LED is mainly used for indoor display of P6, P8, 2020 SMD LEDs are mainly used for indoor displays such as P2 and P3. Under the premise of constant dot pitch, the increase in the size of the LED device can increase the display area and reduce the graininess, but the decrease in the black area will reduce the contrast; on the contrary, the reduction in LED size reduces the display area and increases the graininess The area of the black area increases, increasing the contrast.

8.Consistency

The full-color display is composed of countless pixels of red, green, and blue LEDs. The consistency of the brightness and wavelength of each color LED determines the consistency of brightness, white balance, and chromaticity of the entire display. Sex. In general, 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 device supplier's classification through a spectrophotometer. Voltage consistency is generally not required.

Because LEDs are angled, full-color LED displays also have angular directivity, that is, when viewed at different angles, their brightness will increase or decrease. In this way, the angular consistency of the three colors of red, green, and blue LEDs will seriously affect the consistency of the white balance at different angles and directly affect the fidelity of the color of the display video. To achieve the matching consistency of the brightness changes of the three LEDs of red, green, and blue at different angles, scientific design is strictly required in the design of the packaging lens and the selection of raw materials, which depends on the technical level of the packaging supplier. For a display with the best white balance in the normal direction, if the angle consistency of the LEDs is not good, the white balance effect of the entire screen at different angles will be bad. The angle consistency characteristics of LED lamp beads can be measured with an LED angle comprehensive tester, which is especially important for medium and high-end displays.

LED lamp beads, as the highest cost and largest component of LED display, play a leading role in the quality of LED display. Today we will introduce to you why LED lamp beads are the most critical component of LED display screens, how to identify the advantages and disadvantages of LED lamp beads?

The most critical part of Omaha's full-color LED display is LED lamp beads. There are three reasons:

First, LED is the most used key device in the full color screen machine, and thousands to tens of thousands of LEDs are used per square meter;

Second, LED is the main body that determines the performance of the entire screen optical display, which directly affects the audience's evaluation of the display screen;

Third, LEDs account for the largest proportion of the overall cost of the display, ranging from 30% to 70%.