LED SOLUTIONS

• LED screen: For an piece of LED screen, it is consisted of several LED panels, or cabinets, or tiles, in various sizes like 640x480mm, 500×500/1000mm. They are connected with each other by the locking gears on their sides and secured tightly to form a large piece. When plugged with electricity, it runs colors, or media contents that are sent from a video processor. Its size are flexible and tailorable, mostly depending on the panel’s size.

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• LED panel: A complete unit case made of aluminum or magnesium, or iron to be part of an LED screen, inside which there are several LED modules, one integrated HUB board, one power supply unit, one receiver card, and a paired power cables and Ethernet cables. With all those electrical components on, it displays colors and media contents, but with very limited quality, a mall resolution as we say. For convenience’s sake, panels are placed inside flight cases, for example, so that they can be carries away easily, and one man or two can build an LED video wall with little effort by simply putting them together in rows and columns.
• LED module: A small piece of pane with an LED matrix soldered on it. Normally, it has a plastic base behind it and is fixed by tiny screws. Nowadays, it is barely a thin industrial PCB, on which LED chips are soldered at front face and types of ICs at back side to control those LED chips. It has varied sizes that fits into an LED panel. Like an LED panel, its size also can be made or designed according to specific demand or serve certain purpose.

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• Pixel pitch: A measurement for distance between two LED chips that give out light of red, blue or green, or three mixed colors. It is the space of two LED chips. It is seen and can be measured, and used to calculate the resolution of an LED screen, such as 4K, that is 3840×1920, meaning there are 3840 LED chips in each row, and 1920 in each column. The bigger the pixel pitch, the more grainy the LED screen looks.
• LED: LED chip, technically speaking, emits colorful light when two electric poles connected to electricity. Red, green, and blue light-emitting nodes are integrated inside so that it sends out colorful light. The order of RGB nodes can be arranged differently.

Depending on the specific need, the LED screen be certain size, such as the spatial layout, genres of media contents (1080P, 2K/4K), or viewing distance, or visual effect, or fill-the-bill plan.

Viewing distance is a distance range that allows audience to appreciate the screen quality in a comfortable way. Optimally, a factor ranged 0.8 – 1.2 multiplies the pixel pitch and 100 gives a cozy visual experience. For example, for a pixel pitch of 3.91mm, 3.1 – 4.8 meters are a good measurement for that LED screen. But for some cases like a concert, viewing distance is not the only standard to judge – height, media content, brightness, etc., are more crucial aspects to consider the size of an LED screen. 

• Driver IC: A 16-pin integrated circuit, with eight pins on each side, dedicated to the controlling of an LED chip. Scanning mode(scan rate) is one of the leading factors that affects the visual performance of an LED screen.
• Receiving card: A physical device (functioning partially like graphic card) as a bridge between an LED video wall and its video processor behind a terminal. Its main role is decoding and distributing the video signal received from a video processor; and also controls brightness and colors, etc. through calibration on the control pane through software.
• Refresh rate: A rate describing how many times per second a frame is redrawn on the display. (Typically, 1920, 3840, 7680Hz)
• Scan rate: Also known as multiplexing. One output pin of a driver IC drives multiple LEDs. This is done by completing the circuit for each LED one by one (multiplexing). During one refresh cycle, all the LEDs will light up once. Typical scan rates are 64:1, 16:1, 8:1.
• Frame rate: The number of frames per second. This is typically determined by the video source. (Typically, 24, 50, 60Hz).
• Contrast: The difference in luminance or color, comparing to its surroundings, that makes an object distinguishable. Contrast ratio is the range from the highest level to the lowest level. The higher the value, the more details (finer) it can show or present against its background.
• Scan line: Visual, physical effect your eyes or the camera catches when the refresh rate is low. A camera is more sensitive than our eyes to scanlines. Typically higher refresh rates are desirable and genlocking(synching) the refresh rates between the screen and camera is necessary to balance that effect.
• Moiré effect: Also known as moiré patterns or moiré fringes, is large-scale interference patterns. For the moiré interference pattern to appear, two patterns must not be completely identical, but rather displaced, rotated, or have a slightly different pitch, like between camera and LED screen.