LED Display Control System Explained

LED displayLED display control system, also known asLED displayScreen controller, LEDto showWallpaper card. It is the central component of the LED display screen. He is mainly responsible for receiving screen and video display information from the IT serve port or the DVI interface, the layout of the frame and generation of serial display data and the scan control calendar that LED display can recognize in the partition reader method.

Thanks to the analysis of the points matrix module and the control circuit, the composition of the components of the LED display screen is determined; Thanks to the analysis of the microcontroller and the intelligent control module, the composition structure and the LED display screen driving method are determined and the display of the LED display screen is made.

Depending on the application of the LED display control system, the architecture and the workflow of LED graphics and text display screens are designed. Among them, the Software System and the Wireless Transmission Control Material The main system use serial communication to complete the program download to carry out the transmission of textual information.

1 global analysis of the LED display control system

The LED display system consists of LED graphics and text display system consists of a software control system, a wireless transmission system, a main equipment controller, a LED display, power and other parts. The basic structure is as follows:

System work process: The main tasks carried out by the software control system are graphic editing, extraction and storage of words, image preview and transmission of files; The wireless transmission system mainly complete the file information transmitted from the LED to LEDmonitorThe main task of the LED points matrix in the equipment control system is to complete the display of information via current control, and drive the LED points matrix line by scanning and drive the microcontroller, carry out the equipment driving and finally perform the graphical display function received.

2 Analysis and design of the computer software module

The software module is divided into a publishing piece and a control communication piece. The publishing part performs the editing function of graphic and text files. The communication part completes the transmission of files to the storage module of the microcontroller via an RS-232C series communication. The communication section will be introduced in detail in chapter 3. System design adopts the Windows operating system and opens the text editing window. The pixels of the customer zone are the same as those of the display screen of the LED points matrix. The functions are similar to the Word Document editing tools, including editing modules, drawing modules, text editing modules, color control modules, display effects, preview modules and information download modules.

2.1 Modify module

1) In addition to the clip, copy and stick functions generated by Windows, the system added cancellation and double functions.

First of all. The selection of the cancellation function can carry out the cancellation function step by step of the previous publishing work. Then, select the rehearsal function to implement the most recent operating command of the previous publishing work.

2) Drawing: graphic drawing functions, including straight lines, rectangles, ellipses, circles, etc.

3) Text edition: Includes the edition of the text in various policies, police forms, font sizes, effects and colors, and add the edition of the text to the location specified according to the special objective of the application.

First, select the text function, reveal the font to select the frame and you can select the text from various fonts for publishing. After that, call the specific text positioning dialog box and enter the horizontal and vertical coordinates of the text and the required display position.

4) Color control module: due to the specific characteristics of the application field, three colors: red, green and yellow are mainly used, which can carry out color control.

2.2 Add an effect module: by adding display effects and transmitting multi-screen files in communication, the control system functions are improved.

1) Normal effect, staticly display information on the screen.

2) The scrolling effect can make a scrolling display of information from left to right and can be displayed interspersed with static information.

3) Single screen transmission to storage the editing information to be transmitted.

4) Transmission of multi-screen information, perform the information published and saved to the single screen in a single file, considerably reducing cumbersomeness when transferring files.

2.3 Image overview module: The preview function of information on the Word module is carried out before the file transfer, which can make any form of information on the Word module saved before preview, and is directly integrated into the toolbar file to open the function key button.

1) Display the effect. Thanks to the overview before the file transfer, the order to arrange static display and scroll effects can be adjusted.

2) View time and display the time interval between display information on different screens. The structural diagram of the software module is as follows:

3 LED display control technology

With the development and use of the fifth generation of “Array” control system, the birth of this generation of control systems has further improved the technical advantages of Yuanheng Optoelectronics in screen control and further improved the technology of displaying the display signal. After adopting the “Array” control system.

First, the frequency of change of frame of the display screen can be increased from 60 Hz current to more than 120 Hz, which is much higher than the recognition capacity of human eyes, so that no stroboscopic or wave of water occurs during visualization, improving the quality of the screen.

Second, the gray level level of the three primary colors of the red, green and blue screen can be increased by the current level 256 at level 1024, which makes colors more vivid, color reproduction is better and the images displayed are more realistic.

Finally, the LDVS signal is used for transmission, which maximizes the signal loss, synchronizes the display content of the display screen set, improves the consistency of the display screen and does not have color differences in color difference on the entire display screen.

3.1 Energy saving technology and consumption reduction

Since the network control system is adopted, the loss of brightness of the display screen caused by a gray level can be effectively reduced. According to comparative calculations, the loss of the traditional “centralized control system” system is between 30% and 40%, and the loss of the “bay control system” system is between 8% and 10%. Reducing the loss of the control system is conducive to improving the display of the display screen or reducing the current of the display screen under the same brightness requirements, thus making the effect of the reduction in energy saving and the reduction in consumption. Since the centralized control systems control range is important, in order to maintain a certain refresh rate, they must reduce the number of scans and reduce the brightness to form gray levels; Since the network control systems control range is low, the number of scans can be considerably increased and loss of brightness becomes smaller. The number of scannings in a table of tables can reach more than 136 games, while the maximum number of scanners in a centralized system can reach 42 games.

Depending on the principle of loss of brightness, the calculation table is compared as follows: a complete display screen of 200 squares of 3906 squares / square meter in color, if a driving current of 20 mm is used, the maximum theoretical brightness can reach 15,000 cd / m2. If the maximum actual brightness of 6,000 CD / m2 must be reached, the “centralized control system” is adopted. According to 30% of the loss of the system, the current driving current is 11.4 mm / pixel point and the maximum supply current is 607A; If the “network control system” is used, the maximum actual brightness of 6,000 cd / m2 is used, and according to 10% of the loss of the system, the driving current of the display is 8.89 mA / pixel point, the maximum current is 474A and the amplitude of energy saving reaches 21.9%. Calculated according to average energy consumption is 40% of maximum energy consumption, calculated on the basis of 10 hours of use per day and 300 days per year, annual energy consumption of 160,248 degrees is 160,248 degrees. Annual energy consumption of the “table control system

3.2 Detection technology at one point

In order to improve the reliability of the screen and increase maintenance convenience, Yuanheng Optoelectronics has developed a single point detection technology for display screens. Usually, the detection of LED pixels before leaving the factory is visually tested (that is to say if the human eye sees if it is enlightened according to the debugging program). During the visualization of LED pixels for a long time, it is inevitable that there will be a certain visual fatigue, judgments or missed judgment errors, and its work efficiency is not high. Now our company uses the single -point detection function of the screen. Simply run the corresponding program to determine the working condition of the pixels, thus repairing it, considerably improving the reliability of the screen. At the same time, with LEDDisplay technologyWith continuous development, the super-large LED screens have emerged on the market. This type of screen is generally installed at a higher position and has a long visualization distance, which brings drawbacks to detecting the display screen. The judgment of each pixel point can often be based only on human judgment. After using the single point detection function, maintenance staff can easily find the default coordinates and replace it quickly.

3.3 Brightness and chromaticity correction technology at a point

The uniformity of the brightness and the chromaticity of the LED display screens has always been a major problem that afflicts the initiates of the industry. It is generally believed that the unequal brightness of LEDs can be corrected at a single point to improve the uniformity of the brightness, while unequal chromaticity cannot be corrected, and it can only be improved in subdivisation and detection of LED coordinates. As the requirements of people for LED displays become higher and higher, the subdivision and filtering LED coordinates can no longer satisfy the difficult eyes of people. It is possible to completely correct the display screen to improve color uniformity. First of all, the brightness and chromaticity at a certain level are incoherent due to the difference in the LEDs themselves (for example: if you use the same current to light up two green LEDs in the same production batch, the brightness can change by 30% and the wavelength can change from 10 to 15 nm). Second, after having used it for a period of time, the blue LED will become the most serious and the red will become the least gradation, but the biggest problem is that the LED will become different after a period of time. Therefore, even if the LED screen has perfect consistency in the factory, as the LED becomes darker, consistency will be lost. After three years of continuous use, the inconsistency of the LED screen will be discovered significantly. To this end, Yuanheng Optoelectronics uses advanced advanced technology of brightness and monochromatic chromatic advanced in the world (also known as: signing technology of brightness and chromaticity) to solve the problem of inconsistent color rendering caused by an incoherent attenuation of light elementary diodes in different colors.

Display technology,LCDIt is a display screen composed of liquid crystals, and LEDs are display screens made up of light emitting diodes. Each pixel unit of the LED digital display is a light emitting diode, and a monochrome LED display screen is generally a red light diode.

4 Summary

In recent years, national LED displays technology has developed. The LED display screens of my country have occupied 80% of the world market, but the development of display screens is not in my country. To this end, LED manufacturers in industry such as Radisson Optoelectronics will actively develop and improve LED technology. The overall design of the LED display software control system determines the system process and completes the system software control function. According to the specific communication requirements of the equipment, series communication technologies are adopted to introduce the relevant knowledge of the communication of the port and the serial communication protocol to carry out the communication between the control system and the part of the equipment device, and complete the text transmission function of the LED display screen. Technical control of LED display screens is an important guarantee to determine the quality of the product.