Small spacing LED display refers to indoor LED display with LED point spacing of p2.5 and below, mainly including p2.5, p2.083, p1.923, p1.8, p1.667, P1.5 and other LED display products. With the improvement of LED display manufacturing technology, the resolution of traditional LED display has been greatly improved.Today, we tend to take LED video display for granted. So do we know how the LED screen works? What is the principle of HD small spacing LED display? In fact, they become the common characteristics of our towns and us, mainly focusing on their external quality parameters.Five core technologies of small spacing LED display
1. Reduce the dead light rate of the display lamp and ensure the stability of the screen
The dead light rate of the traditional LED display screen is one in tens of thousands in the industry standard, but the small LED display screen with small spacing can not be done temporarily. If there is one dead light in 10000 square meters according to the previous standards, the display screen can hardly be seen. Therefore, the dead light rate of small spacing LED display screen must be controlled at 1 / 100000 or even 1 / million in order to meet the needs of long-term use. Otherwise, if there are a large number of dead lights for a period of time, users can't accept it.
2. Achieve low brightness and high gray
Many people know that human body induction lamp is different from outdoor display, which requires high brightness, high refresh rate and energy saving. Indoor display needs to reduce the brightness. Experiments show that from the perspective of human eye sensitivity, the brightness of LED (active light source) is twice that of passive light source. In terms of specific data, the best brightness for small spacing led to enter the room is 200-400cd / m2. However, the gray loss caused by reducing brightness needs to be completed through technical supplement. At an exhibition of lianchengfa in 2016, the large screen display performance network released the test samples of small spacing led and gave the test methods and standards. The test shows that at present, only a few LED display manufacturers can achieve low brightness and high gray at the same time, and most manufacturers need to improve to a certain extent.
3. Standard resolution of signal source
Unlike the outdoor display, the outdoor advertising chamber of Commerce selects the content and display suitable for playback according to the resolution of the display screen. The indoor display signal source has certain standards. As a manufacturer of LED display screen, it is not required that the signal source connected to the indoor must adapt to the resolution of the display screen, but to adapt to the needs of the indoor signal source and design and ensure the corresponding resolution, So as to meet the needs of users as much as possible. Fortunately, after more than a year of understanding of indoor LED display products and customer needs, lianchengfa has completed this transformation and greatly met the needs of the majority of users.
4. Support system access, display and control of multi signal and complex signalCompared with the outdoor display signal, the display signal of small spacing Lede display is characterized by multi signal access and complex signal access, such as multi place video conference, which requires remote access signal, local access signal and multi person access. The experiment shows that the simple implementation of multi signal access through excessive screen cutting scheme will reduce the signal standard. Therefore, how to solve the problem of multi signal and complex signal access also needs the technical support of small spacing led.5. Realize seamless joint and high-speed correction
The biggest advantage of small spacing LED display is seamless, but it requires high splicing. For liquid crystal, as long as the seam is uniform, there is no problem, and the seam is not obvious. However, the small LED spacing can not be like this. If the modules are too tight, there will be bright lines. When the modules leave, there will be dark lines. So it's not easy to splice well. Therefore, the process and correction technology of the box and the guarantee and good combination of efficiency need to be guaranteed.Scanning mode of small spacing LED displayDynamic scanning: dynamic scanning implements "point to column" control from the output of driving IC to pixel points. Dynamic scanning requires control circuit, and the cost is lower than static scanning, but the display effect is poor and the brightness loss is large.
Static scanning: static scanning implements "point-to-point" control from the output of driving IC to pixel points. Static scanning does not need control circuit, and the cost is higher than dynamic scanning, but it has the advantages of good display effect, good stability, small brightness loss and so on.With the development of LED technology, the brightness of LED electronic display screen is also increasing, and the size is becoming smaller and smaller, which shows that more LED small spacing electronic display screens will become the general trend.
However, the improvement of brightness and pixel density of LED small spacing display also brings new and higher requirements to the control and drive of LED small spacing display. As far as the general indoor screen is concerned, the current common control methods adopt the row column split control mode, which is commonly referred to as the scanning mode. At present, the driving modes of LED small spacing display screen include static scanning and dynamic scanning. The static scanning is divided into static real pixels and static virtual, and the dynamic scanning is also divided into dynamic real image and dynamic virtual;
In the LED small spacing display screen, the ratio of the number of rows lit at the same time to the number of rows in the whole area is called scanning mode. The scanning is also divided into several driving modes, such as 1 / 2 scanning, 1 / 4 scanning, 1 / 8 scanning and 1 / 16 scanning. In other words, if the driving mode of the display screen is different, the setting of the receiving card is also different. If the receiving card was originally used on the 1 / 4 scanning screen and is now used on the static screen, the display on the display screen will be bright every four lines. Generally, the receiving card can be set. After connecting the sending card, display screen, computer and other main devices, you can enter the relevant software on the computer for setting. Here we will first introduce the scanning mode and principle of LED small spacing display screen.
Display principle of HD small spacing LED screenLED screen display resolution (so-called spatial resolution), which is closely related to the distance or pitch between pixels in LED video display;Maximum brightness of LED screen: the dynamic brightness range is understood as the number of brightness levels of the screen that can be supported (sometimes referred to as radiation or energy resolution);
LED screen frame rate usually measures the frequency of frame change per second (FPS) (sometimes referred to as time resolution) of new data display that a video source can feed the whole frame;The number of LED screen refresh rate (in Hertz) is to draw data in the second display hardware, or refresh frame (also known as time resolution);Spectral resolution of LED screen: color images distinguish light of different spectra. Multispectral images solve even better than the need for different wavelengths of spectrum or copied colors. This word determines how many spectral components create an image; Color uniformity throughout the screen; Possibility of white balance and fine adjustment;
Linear brightness sense of LED screen - subjective image quality, which determines the human eye to distinguish the dark and bright parts of the screen with adjacent brightness levels;LED screen image comparison; Image quality depends on the viewing angle. In addition to image quality, it is important to consider some key operating parameters of LED video display.The principle of high-definition small spacing LED display is briefly described; Mature software and integrated control system enable the system to expand and build led and LCD video display network and remote control through the Internet and built-in information security subsystem; The level of electromagnetic radiation is in the form of electromagnetic interference (EMI) from the screen.