Quality and quality of full-color LED display
First of all, the most important thing is the lamp bead of the full-color led display. Why is the lamp bead so important? It is obvious that the quality of the lamp bead directly affects the display effect of the full-color led display. The led lamp bead is used in the led display. The most important key elements, each square is thousands, tens of thousands to hundreds of thousands of lights.
Secondly, it is brightness. For outdoor full-color LED display, brightness is a very important issue, but the problem of brightness will directly involve another problem, that is, the problem of heat dissipation.
The quality of a full-color LED display can be identified from the following aspects:
1. Flatness: The surface flatness of the LED display screen should be within ±1mm to ensure that the displayed image is not distorted. Local protrusion or recession will cause the viewing angle of the display screen to appear dead angle. The quality of the flatness is mainly determined by the production process.
2, brightness and viewing angle: indoor full color screen brightness should be above 800cd/m2, outdoor full color screen brightness should be above 1500cd/m2, in order to ensure the normal operation of the display, otherwise it will be too bright because the brightness is too low The image displayed. The brightness is mainly determined by the quality of the LED die. The size of the viewing angle directly determines the number of display audiences, so the bigger the better. The size of the viewing angle is primarily determined by the way the die is packaged.
3, white balance effect: white balance effect is one of the most important indicators of the display. In color theory, when the ratio of the three primary colors of red, green and blue is 1:4.6:0.16, pure white will be displayed. If there is a slight deviation in the actual ratio, the deviation of white balance will occur. Generally, it should be noted whether white is blue or yellow. Green phenomenon. The quality of the white balance is mainly determined by the control system of the display screen, and the die also has an effect on the color reproduction.
4. Reducing color: The reductiveness of color refers to the reduction of color on the display screen. The color displayed on the display screen should be highly consistent with the color of the source, so as to ensure the realism of the image.
5. Whether there is mosaic or dead point phenomenon: Mosaic refers to the small four-square block that appears on the display or is always black. The main reason is that the module is necrotic. The main reason is that the quality of the plug-in program used in the display is not good. The dead point refers to a single point that is always bright or often black on the LED display. The number of dead points is mainly determined by the quality of the die.
6. There are no color blocks: color blocks refer to the obvious color difference between adjacent modules. The color transition is based on the module. The color block phenomenon is mainly caused by the poor control system and the gray level is not high. , caused by a lower scan frequency.
Factors affecting the quality of full-color LED display
1, 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. Generally speaking, according to industry experience, the failure rate before the assembly of the led display starts to aging for 72 hours before shipment should be no more than three ten thousandth (refer to the failure caused by the LED device itself).
2, antistatic ability
LEDs are semiconductor devices that are sensitive to static electricity and can easily cause electrostatic failure. Therefore, antistatic 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.
3, attenuation characteristics
The red, green, and blue LEDs all have a characteristic that the luminance is attenuated as the working time increases. The advantages and disadvantages of LED chips, the quality of auxiliary materials and the level of packaging technology determine the attenuation speed of LEDs. In general, after 1000 hours and 20 mA ambient temperature lighting test, the attenuation of the red LED should be less than 10%, and the attenuation of the blue and green LED should be less than 15%. The consistency of red, green, and blue attenuation has a great influence on the white balance of the full-color LED display in the future, which in turn affects the display fidelity of the display.
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. 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. For displays with different dot pitches and different line of sight, a balance should be found in brightness, angle and price.
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 uniformity of the entire display. Sex. In general, display manufacturers require device 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 device 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. 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, depending on the technical level of the 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 angular consistency characteristics of LED devices can be measured by the LED angle comprehensive tester, which is especially important for medium and high-end displays.
Hello, please leave your name and email here before chat online so that we won't miss your message and contact you smoothly.