LED Large Screen Display Commonly Used Concept Parameters

- Aug 18, 2017-

LED large screen pixels

Is the smallest unit on the screen can be independently controlled, PIXEL is the abbreviation of pictureelement, in the three primary colors on the screen, the pixels consists of three parts: red, green, basket, each part by one or several led composition, theoretically, respectively Red, green, blue brightness, can show any color.

Spacing: the center distance of adjacent pixels. The smaller the pitch, the shorter the visual distance.

Resolution: usually used for digital display devices, said the total number of pixels, generally written in the form of wide X high, such as 800X600.

 Visual angle: When the observer faces the maximum brightness that can be seen, when the observer to the left or right to move, see the brightness will be reduced, when the brightness is reduced to half the maximum brightness, where the The angle plus the sum of the angles obtained in the opposite direction is called the horizontal viewing angle and the vertical viewing angle is measured in the same way. The angle of the manufacturers will give parameters.

Brightness: the most important parameter in any display device. Brightness of the main unit called candle (candela), said CD, a single LED brightness is usually used millicandelas, MCD, that is one thousandth of a CD, put a square meter of LED brightness together to get the brightness of the unit area, with the (NITS), 1NITS = 1CD / m2

Visual distance: for a variety of LED display, the best observation distance should be the human eye can not tell the minimum distance of the pixel, the distance is about 3400 times the point spacing. Television and computer observations are usually less than this requirement, but the acceptable distance can not be less than 1700 times the point spacing.

Picture update rate / refresh rate: the screen screen update rate, usually in hertz (Hz), and the frame rate is different.

Frame rate: The number of image frames displayed per second on the screen, usually depending on the input signal (25fpsforPAL, 30fpsforNTSC)

Field frequency: PAL and NTSC half frame, because PAL and NTSC are interlaced, each refresh only shows the field image.

Color temperature: red, green and blue colors must be balanced in order to accurately restore the true color, in other words, LED white must be white, not pink. If the red, green and blue are at the highest brightness, the mixed color is usually not white, in order to get white (commonly known as 6500K color temperature), red, green and blue must have one or two brightness down, in order to obtain the correct white, must Repeated measurements to adjust the brightness, this process says white balance, LED display price.

Grayscale: LED screen can show the number of colors depends on the RGB three-color gray level, in the standard full-color screen for the 256 gray, for the stadium LED full color system, 256 gray is not enough, can not Accurately restore the restored color. Also known as the color depth, refers to the number of different brightness, red, green and blue have their own gray, in the full color system is generally 256 gray, can produce 256X256X256 = 16,777,216 kinds of colors in the PC called 24-bit color, In the LED display system called 8-bit system.

Color: LED large screen by the combination of red, green and blue to produce a variety of colors, but these three colors are made of different materials, the angle of view is different, different LED spectral distribution are changing, which can be observed The difference is called color difference. When the angle of view of the LED, the color changes, the human eye to judge the true color of the screen (such as the film screen) than the computer generated by the screen is better.