1. According to the display method, the full-color LED display system is divided into three categories
Graphic display system
Generally, the LED display that displays graphics and text is called a graphic screen. The main feature of the graphic screen is that each light-emitting device in the LED dot matrix is only on or off, and the strength cannot be controlled, which means that this type of screen has no gray level control.
Picture display system
The image display screen is relative to the graphic display screen. It refers to those screens with gray levels. The pictures it displays are more vivid and lifelike. The main feature of the image screen is the use of limited gray levels and color modulation to display Images that do not require high color and grayscale.
Full color led display
Video display system
Based on the research of the display screen control system, the LED display that can receive the video signal and display the moving, clear, full-color image is called the video display screen.
2. According to the control method, we divide the display system into two categories
Communication display system
The communication display screen is an asynchronous display screen. The asynchronous mode means that the LED screen itself has the ability to store and automatically play, and display information such as text and non-gray-scale pictures edited on the PC or the location code and picture of Chinese characters. Numbers, etc. and various control commands are transmitted to the LED screen controller through the serial port or other network interfaces, call various data information pre-stored in the controller, and process the received instructions into the dot matrix data required by the display screen according to the requirements and publish to the display On the screen. This type of screen generally does not have the capability of multi-level grayscale display, and is mainly used to display text and simple graphic information, and can be connected to multiple screens. This method must require a controller with a CPU to process the information.
Real-time mapping screen system
The real-time mapping screen is a synchronous display. The basic function is to realize the real-time mapping of the computer screen content on the LED display, including displaying Video video images with the support of the multimedia card. Take the data from the feature port of the host graphics card or the video card to take out the displayed data processed by the graphics card, and then perform certain processing on these data and send them to the LED display. This method can be realized without a controller with a CPU, or even by making a hardware card.
256-level grayscale LED display system can make the LED display screen complete the synchronous display with the computer, and make it achieve high-performance display effect. The 256-level grayscale LED display control is composed of a multimedia card, a video controller, a long-line driver, a receiving card and a display unit. The video controller obtains the digital display signal from the standard display interface of the multimedia card and converts it into the signal format required by the display. It can also obtain the control signal from the standard interface of the computer. The user completes the control of the LED display through the computer software. Adjust, and make the display screen can adapt to different specifications of multimedia cards, with a high degree of compatibility.
3. Classification from the way of communication
Wired communication method
A communication method that uses tangible physical media such as cables and optical fibers as the media. As far as the current application is concerned, data transmission is generally carried out through a dedicated channel. This method has a higher cost. I believe that the wired communication based on the public network will be more widely used in the future. Using Interent for data transmission is also one of the main methods used by this system.
Wireless communication method
The information is sent from the monitoring center through radio waves between the LED screen controller and the monitoring center within the communication distance. This way saves system investment, shortens the construction period, and reduces the possibility of the system being stolen. This way of communication has a form similar to mobile phone short messages, using GSM, GPRS or CDMA networks for transmission, and also using broadcast towers, using FM or AM for signal transmission and reception.
asynchronous control
LED display asynchronous control system is also called LED display offline control system or offline card. Mainly used to display a variety of text, symbols and graphics or animation. The screen display information is edited by the computer, pre-installed into the frame memory of the LED display through the RS232/485 serial port, and then displayed and played screen by screen, cyclically, the display mode is colorful and varied. Its main features are: simple operation, low price and wide range of use. The LED display simple asynchronous control system can only display digital clocks, text, and special characters. In addition to the functions of a simple control system, the LED display graphic asynchronous control system has the biggest feature that it can control the display screen content in different areas. Support analog clock display, countdown, picture, table and animation display. With functions such as time switch, temperature control, humidity control, etc.
Synchronous control
LED display screen synchronization control system, mainly used for real-time display of video, graphics, notifications, etc. Mainly used for indoor or outdoor full-color large-screen displays. The working mode of the LED display synchronization control system is basically the same as that of a computer monitor. It maps the image on the computer monitor in real time with an update rate of at least 60 frames/sec. It usually has a multi-gray color display. Ability to achieve multimedia advertising effects. Its main features are: real-time, rich expressiveness, complicated operation, and high price. A set of LED display synchronization control system generally consists of a sending card, a receiving card, and a DVI graphics card.
