1) physical indicators Pixels from the center pixel pitch (distance between points) Adjacent pixels distance between the centers. (Unit: mm) Density density (points) Pixels per unit area on the number of points (unit: Point / m2). Points with the point there is a certain distance calculation relations Is the formula: Density = (1000 ÷ pixels from the center) LED screen, the higher the density, the more clear image, the smaller the range of the best viewing distance. Best line-of-sight Density (points / m2) Point distance (mm) Best line-of-sight (m) 　 　 Recent Farthest 44100 4.75 2 26 40000 5 3 28 17200 7.625 4 42 10000 10 5 55 6944 12 8 66 3906 16 15 88 2500 20 20 110 2066 22 20 140   Viewing distance icon Flatness level up degree Light-emitting diodes, pixel, display modules, display modules in the composition of the LED display when the plane's deviation die. LED display easily lead to poor flatness to watch, uneven color  screen.   2) electrical performance Gray-level gray scale LED display with a brightness in the dark from the brightest to be able to distinguish between the brightness of the series. That is, the so-called gray or gray color, brightness refers to the degree of light and shade. The digital display technology, the gray color of the show is the determining factor. Generally speaking, the higher the gray, the more rich color display screen and the more delicate, more details of the performance of the rich. Gray-level system depends largely on the A / D conversion of the median. Of course, video processing system chips, memory and the transmission system should provide appropriate support to the median it. For general non-gray, 8, 16, 32, 64, 128, 256 and so on, LED display, the higher the level of gray, the colors more rich, more beautiful color; On the other hand, showed that a single color, change Simple.     At present, domestic LED display mostly uses 8-bit processing system, that is, 256 (28) gray-scale level. Is simple to understand from white to black there are 256 kinds of changes in the brightness. RGB using the three primary colors can pose a 256 × 256 × 256 = 16777216 colors. Known as the 16 trillion colors. The main screen of international brands using 10-bit processing system, that is, the 1024 gray, RGB to RGB color constitute 1,070,000,000. Frame-for-frequency refresh frame frequency  LED display screen LED display updated information on the frequency. General for 25Hz, 30Hz, 50Hz, 60Hz, and so on, for-frame, the higher the frequency, changes in the image of continuity, the better. Refresh rate refresh frequency  LED displays show the data per second to be repeated more frequently. Often 60Hz, 120Hz, 240Hz, and so on, the higher the refresh rate, more stable image display.    3) optical indicators    显示屏亮度luminance of LEDscreen   Screen brightness luminance of LEDscreen LED screen in the direction of the normal average brightness. Unit: cd/m2. At the same point under intensity, LED display brightness depends on the use of the LED chip material, in the form of packages and sizes, the larger the chip, the higher the brightness; On the other hand, the lower the brightness. And the brightness is directly proportional to the size of the chip icon   Angle viewing angle In the horizontal and vertical directions of the brightness of LED displays direction of the normal brightness of the half, the LED display and observe the direction of the normal angle of perspective and were referred to as the level of vertical angle, usually around and up and down, said ± The number of degrees.    If you display a level angle of 120 degrees vertical angle of 45 degrees, in this view within the framework of all the audience can enjoy watching the best results. Beyond the scope of the audience will be able to watch 50% lower than the normal brightness of the visual effects. LED display of the larger perspective, the more the audience, the more extensive coverage, the smaller the contrary. LED chip packaging to determine the angle of the LED screen size, and LED lights affixed to form a better perspective, oval-shaped single-LED light level better perspective. Perspective and in inverse proportion to the brightness. The scope of perspective Light wood The level of Vertical LED lights affixed to table 160 160 Oval LED lights 120 45 Round LED lights 60 60 Life display life of LED screen LED is a semiconductor device, the life expectancy of 100,000 hours. LED display of their life depends on the use of LED lamps and displays the life span of electronic components used in life. General MTBF of not less than 10,000 hours.