What Are The Working Principles Of Led Displays

一、Core Component: Light Emitting Diode led:

Leds are the pixels of an led display screen, which are the most basic light emitting units.

①Electroluminescence: When an electric current passes through a special semiconductor material, electrons and holes recombine, releasing energy in the form of photons, thus emitting light.

②Color principle: A single led chip can only emit one color of light, we use led chips of three basic colors to mix and create full color: R（Red）G（Green）B（Blue）.

二、Basic Components: Pixels and modules:

①Pixel: The smallest unit capable of displaying a complete color, on an led display, a pixel typically consists of a red, a green, and a blue led chip. These three chips are arranged closely together, appearing as a dot that can change color from a distance.

②Module: An led module is a standardized unit that is easy to assemble and maintain, consisting of a certain number of pixels, such 16×16=256 pixels, along with driving circuitry and a PCB printed circuit board, multiple modules are assembled together to form the physical structure of the entire display screen.

三、Control System: Brain and nerves: This is the soul of the led display screen, mainly composed of three parts:

①Video source: Devices that provide the original image signal, such as computers, DVD players, TV boxes.

②The controller sending card receives signals from the video source and processes them, its core task is to segment the complete video frame, calculate the R, G, and B brightness values ​​that each pixel on the screen should display at each moment, and after processing, send the allocated data to the scan driver via network cable or optical fiber.

③Scan driver receiver card and driver IC, receiver card: Usually installed on the module, responsible for receiving data from the controller.

④Driver IC: This is the switch that directly controls the led chips, based on data from the receiver card, it controls the current flowing to each R, G, and B led chip at extremely high speeds microseconds, higher current makes the led brighter, lower current makes the led dimmer.

⑤Scanning Method: To save costs and reduce power consumption, driver ICs typically use a scanning drive, for example, on a 1/16 scan screen, the driver IC sequentially lights up the first row, the second row, and so on up to the 16th row, then quickly cycles back. Because this cycle is extremely fast typically hundreds to thousands of times per second, utilizing the persistence of vision effect of the human eye, we still see a complete and stable image.

四、Complete workflow:

①Signal input: The computer plays a video, and the video signal is output through interfaces such as HDMI or DVI.

②Signal Processing: The controller transmitting card receives the signal and decodes and re encodes the video image, it breaks down the entire image, precisely calculating the R, G, and B brightness values ​​needed for each of the millions or even tens of millions of pixels on the display screen in the next moment.

③Signal distribution: The controller sends the processed data to the scan drivers receive cards of each area of ​​the display screen via cables.

④Pixel driver: The driver IC receives data and converts it into specific current signals, it precisely controls the luminous intensity of the red, green, and blue chips in each led pixel.

⑤Imaging: Countless controlled pixels emit light simultaneously in a scanning manner, mixing to create different colors, when these pixels are densely packed enough, from a distance, the light they emit forms a complete, dynamic color image.

五、Key technologies and concepts：

①Pixel pitch: This refers to the distance between the centers of two adjacent pixels, measured in millimeters mm, this is the most critical parameter determining the sharpness of a display screen. The smaller the pixel pitch, the more pixels per unit area, resulting in a more detailed and clearer image. P2 and P3 displays, as commonly referred to, indicate screens with pixel pitches of 2mm and 3mm, respectively.

②Refresh rate: refers to the number of times a display screen updates its image content per second, measured in Hertz Hz, a higher refresh rate results in a more stable image and reduces the likelihood of scan lines and ripples during shooting.

③Grayscale level: refers to the number of shades an led pixel can vary from its darkest to its brightest, a higher grayscale level results in more natural and richer color transitions and stronger detail reproduction.