Color led large screen drive technology is further optimized

The color LED large screen drive technology is further optimized, and the color LED large screen is extremely versatile, and can be used for stage backgrounds, outdoor and indoor advertisements, station departures, banks, securities, stadiums, etc., and the original color LED large screens did not have a very high refresh rate. High, customers have no special requirements for LED screen refresh. As the spacing becomes smaller and smaller, the number of pixels loaded by the control chip continues to increase, which leads to a further decrease in the refresh rate of a single driver. In order to solve the problem of LED screen flicker, it is necessary to Only by increasing the refresh rate can the picture quality of the LED large screen be free from jitter effects. As the largest outdoor application product, color LED large screen is an indispensable product for large-scale entertainment, sports events, large screens in squares and other places. From single and double-color simple text display to today's high-definition full-color display technology, the display technology has always been in the forefront. Progress, 80% of the world's large color LED screens are produced in my country, and the quality assurance of the screen is inseparable from the stable current design. There are still many places where technology is lacking in our country. The government's strong support for Shenzhen LED large screen companies has led many indoor LED large screen manufacturers to actively invest in technology research and development. At present, all LED large screen manufacturers are applying for their own patents for independent research and development. The application of some LED chips in the market in my country shows that the technology of my country's LED industry is improving and showing a prosperous scene.

The drive current keeps decreasing. Earlier TLC5940 had a single-channel drive current capability of 120mA, and later the current drive capability of TB62726, ST2221, and MBI5026 was reduced to 80-90mA. At present, 45mA current drive capability is basically adopted, such as MBI5024 and CYT62726. The main reason for the reduction in current drive capability is that the luminous intensity of LED devices is getting higher and higher. In order to improve image quality, static LED large screen designs are more and more used, and the demand for drive current capability is reduced.

From the perspective of IC cost, the chip size can be reduced, thereby reducing the cost. For this purpose, a 25mA static screen driver chip CYT62727 is designed. The origin of the 16-bit shift constant current IC: the two-color LED large screen is mainly for displaying text, and the single-chip scanning is more convenient , due to the increase in the number of LEDs, in order to save O/I resources, the 74HC595 shift scan is used. In order to be more suitable for the application of large LED screens, the constant current setting function is integrated on this basis, the current drive capability is increased, and 16-bit devices are packaged to meet the needs and cost requirements, which are widely used by current full-color screens.

At present, 80% of the world's large LED screens are purchased and produced in mainland China, and 16-channel constant current device design is generally used, which will continue in the short term, and will not disappear in at least the next 5 years, mainly because the supporting control technology is mature, and the products have been series. Unless there is a huge leap in system control technology and chip driver design, and the cost is further reduced, the status quo will not change. The biggest problem is through the control technology, if changing the color consistency of the LED. In recent years, many LED display manufacturers have continuously introduced new architectures, which will be recognized by the market in the future.

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