Led display refresh rate and grey scale analysis

With the development and application of indoor led display more and more, whether in the command center, the monitoring center, and in the studio, you can see the led display screen has been widely used. From the perspective of the overall performance of the led display system, however, whether these screens can meet the needs of users? The led display show images can conform to the human eye to watch? The led display can withstand the test of different camera shutter Angle camera? This is led display need to face the need to take account of the problem, the following powerful giant colour will influence of several factors led display ( Including the refresh rate, grayscale, etc. ) Make a briefly. Led display refresh rate ( Visual refresh rate) 'Visual refresh rate' refers to the screen update rate, usually with Hertz ( Hz) For the unit, said in general visual refresh rate above 3000 Hz, for highly efficient led display. Visual refresh rate is higher, the picture shows the more stable, the less the visual light flashes. Led display low 'visual refresh rate', its influence in addition to the camera, photography, horizontal stripes appear level, at the same time can also occur similar to tens of thousands of star light bulb flickering images at the same time, the human eye when watching it may produce discomfort, and even harm the eyes. Although for the human eye visual refresh rate reach more than 60 hz already felt the footage, but the higher the visual refresh rate, show the image of the more stable, the human eye is not easy to feel tired. Today in high quality video, to get more detailed pictures, such as highlight replays or close-up photography process, are all high speed camera to shoot more than 1000 Hz per second. To what can be taken at this point, the LED display, under the fast shutter speed can still present continuous images ( No black line) Or continuous levels, is a big challenge. Led display of grey scale 'grey scale' refers to the various color between the most dark and bright color, have different change the color of class, generally gray-scale at 14 bit ( 位) Above, with at least 16384 kinds of color class above, for highly efficient led display. Will happen if the gray series is insufficient, lack of color levels or layered color levels is not smooth, and can not fully show the colour of the film. Led display effect is greatly reduced. Some inefficient power led display under 1/500 SEC shutter, already can be checked out the obvious color piece distribution, if we will shutter speed increase, 1/1000 or 1/2000 s s, for example, will be more obvious. What effect is the refresh rate of led display and grey scale? We know that the led display several core components, such as led switching power supply, led driver chip, led lamp bead, etc. , in view of the led display refresh rate and grey level, the led driver chip directly determines the led display in the visual refresh rate, gray levels of performance. In the LED driver chip, high new technology to 'ScrambledPWM ( S - 脉宽调制) 'Technology, S - PWM technology is to improve the traditional pulse width modulation ( 脉宽调制) Technology, it will be an image of conduction time scattered into shorter conduction time, in order to increase the overall visual update rate. Further shows that the new generation of the built-in S - LED driver chip PWM technology, will originally per frame ( 框架) Count ( And LED grain ON grain LED OFF) Way, the average break up into many times to count, and each break up of equal parts, can maintain the original proportion of On/Off before the break. S - PWM technology provides different counting mode, hence the image refresh rate up to the top 64 times. If a change in the S - PWM to improve image refresh rate, with low order clock ( Such as 5 MHZ) The visual refresh rate can be easily increase 64 times, and can reach more than 4800 Hz. Compared with the general video sleep at least more than 10 times higher refresh rate, also can avoid to produce high-frequency electromagnetic interference ( EMIissue) And over voltage surge, 过度) And under voltage surge ( 未达到目标) The problem. S - PWM drive chip led display, camera with digital camera shutter speed, still won't appear black scan lines and color piece distribution level. Its visual refresh rate, gray level, far beyond the use of traditional switch type LED display driver chip. High quality LED driver chip, built in the S - PWM technology, makes the refresh rate is as high as 3840 hz and grey scale up to 16 bits, at a high speed camera shutter case, a horizontal scan lines and black color piece distribution after the meeting.