Small-pitch 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 displays screen products. With the improvement of LED display manufacturing technology, the resolution of traditional LED displays has been greatly improved. So how do the LED screen works? What is the display principle of a high-definition small-pitch LED screen?

Five core technologies of small-pitch LED display

Reduce the dead light rate of display lights and ensure the stability of the screen

The dead light rate of traditional LED displays is 1 in 10,000 in the industry standard, but small-pitch LED small displays still cannot do it for the time being. The display is almost unreadable under the standard. Therefore, the dead light rate of the small-pitch LED display must be controlled at 1/100,000 or even 1/1000,000 to meet the needs of long-term use. Otherwise, if a large number of dead lights appear for a period of time, it’s not acceptable for users.

 Low brightness and high gray

Many people know that human body induction lights are different from outdoor displays that require high brightness, refresh rate and energy saving. Indoor displays need to lower the brightness. Experiments show that from the perspective of human eye sensitivity, LED (active light source) brightness is twice that of passive light sources. As far as specific data is concerned, the optimal brightness of small-pitch LEDs entering the room is 200-400cd/m2. However, the loss of grayscale caused by reducing brightness needs to be completed through technical supplements. At an exhibition in 2016, the large-screen display performance network released test samples of small-pitch LEDs, and gave test methods and standards. The test shows that only a few LED display manufacturers can reach low brightness and high gray at the same time. Most manufacturers need to do a certain improvement.

Standard resolution with the signal source

Different from the outdoor display, outdoor advertisers will select suitable content according to the resolution of the display screen. The indoor display signal source has certain standards. As an LED display manufacturer, it cannot be required to access the indoor signal source. It is necessary to adapt to the resolution of the display screen, to adapt to the needs of indoor signal sources, and to 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 indoor LED display products and understanding of customer needs, Lianchengfa has completed this transformation and greatly met the needs of users.

Support system access and display control of multiple signals and complex signals

Compared with outdoor display signals, small-pitch LED display signals are characterized by multi-signal access and complex signal access, such as multi-location video conferences, which require remote access signals, local access signals, and multi-person use. For example, experiments have shown that simply implementing multi-signal access through the split-screen scheme will reduce the signal standard. Therefore, how to solve the problem of multi-signal and complex signal access also requires the technical support of small-pitch LEDs.

Achieve seamless seams and high-speed corrections

The biggest advantage of small-pitch LED displays is that they are seamless, but they have higher requirements when splicing. For liquid crystals, as long as the seams are uniform, there is no problem, and the seams are not obvious. But the small spacing of LEDs cannot be like this. If the modules are squeezed too tightly, bright lines will appear, and when the modules leave, dark lines will appear. So it is not easy to splice well. Therefore, the process and calibration technology of the cabinet, as well as the good combination of efficiency, need to be guaranteed.

Small pitch LED display scanning method

Due to the improvement of the brightness and pixel density of the LED small-pitch display screen, new and, higher requirements are brought to the control and driving of the small-pitch LED display screen. As far as the general indoor screen is concerned, the current common control method adopts the row-column sub-control mode, which is commonly referred to as the scanning mode. At present, the driving modes of the LED small-pitch display screen include static scanning and dynamic scanning. Static scanning is divided into static real pixels and static virtual, dynamic scanning is also divided into dynamic real image and dynamic virtual.

Dynamic scanning: Dynamic scanning implements “point-to-column” control from the output of the driver IC to the pixel points. Dynamic scanning requires a control circuit, and the cost is lower than that of static scanning, but the display effect is poor and the brightness loss is large.

Static scanning: Static scanning is to implement “point-to-point” control from the output of the driver IC to the pixels. Static scanning does not require control circuits, and the cost is higher than dynamic scanning, but the display effect is good, the stability is good, and the brightness loss is small. etc.

With the development of LED technology, the brightness of LED electronic display screens has also been continuously improved, and the size has become smaller and smaller, which indicates that more LED small-pitch electronic display screens will become the general trend to enter the room.