|LED electronic display led sign board led billboard introduction|
LED electronic display is a large-scale display system integrating microelectronics technology, optoelectronic technology, computer technology and information processing technology. It is widely used in advertising, securities, information dissemination, news release, etc. Display media.
The LED electronic display (LED panEL) is a display screen composed of an array of LED devices for displaying various information such as text, graphics, images, animations, quotes, videos, video signals, etc. through a certain control method.
Evolution history of display methods
The traditional white accumulating lamp can't overcome the defects of large power consumption and short life. Neon lights, advertising light boxes, flat signboards, etc., although the colors are bright, but the changes are monotonous, and can't play video images. The magnetic flip can be assembled by computer. However, it does not have a light source itself, and the effect at night is poor. In recent years, with the rapid development of microelectronics technology, automation technology and computer technology, the update of production technology and the application of new materials, the brightness and life of LED chips have been developed by leaps and bounds, which has made their application fields increasingly broad. The LED display manufacturer market has grown considerably. After 93 years, the appearance of super bright blue, red and green light-emitting tubes made the realization of true color display become a reality. Outdoor display screens have been loved by people, especially in sports fields, advertisements, news and other fields. From the perspective of future development trends, the performance advantages of several media with video effects at present are different:
Cathode tube (crt) or quartz tube (dv) large TV: the cost is very expensive, usually only 37 inches, the size is much larger, it is limited, no need for large screen and indoor use, the effect is ideal.
Color liquid crystal display (led): The same cost is expensive, the circuit is complicated, the area can not be too large, and the angle of view is very large, the viewing angle is small, but the picture is fine and the visual sense is good.
Projection projector: The brightness is small, the definition is poor (the picture is unevenly received by the light), and the advantage is that the installation is convenient and the maintenance is simple.
TV wall (tv-wall): There is a dividing line on the surface, which has a visual sense of foreign body. It is not suitable for text display in outdoor applications, but it is not suitable for text display, but it works well when expressing TV screen indoors.
Led is limited by space, and can be designed according to user requirements, with full color effect and large viewing angle, which can represent text, graphics, images (including animation and video).
China's economy is developing rapidly and there are increasingly high demands on the dissemination of information. It is believed that the LED electronic display will be in the social and economic development with its bright color, large display information, long life, low power consumption, light weight, small space size, high stability, easy operation, easy installation and maintenance. Play an increasingly important role. In general, the LED display is the best choice for today's display media.
LED display application
Rousseff lossew.o.w discovered the light emission of the accidentally formed p-n junction in semiconductor sic in 1923, but the light-emitting diode made by the principle of semiconductor p-n junction electroluminescence was only developed rapidly in the late 1960s.
In recent years, due to the maturity and improvement of the fabrication and processing of semiconductors, LEDs have become increasingly dominant in solid-state displays.
The reason why led is widely recognized and rapidly developed is inseparable from its own advantages. These advantages are summarized as follows: high brightness, low operating voltage, low power consumption, miniaturization and integration with integrated circuits, simple driving, long life, impact resistance, and stable performance. Led has broad development prospects and is currently developing towards higher brightness, higher weather resistance, higher uniformity of illumination, higher reliability, and full color. LED light-emitting chips capable of emitting different colors can be obtained due to different materials of the semiconductor. Video display system and ultra-large-scale programmable integrated chip.
The traditional approach to video display is to use discrete, small-scale integrated circuit technology. When the system performance is greatly improved (such as 16 gray levels increased to 256 gray levels), this technology will seriously affect system reliability and maintainability. After the gray level is increased, as the amount of data calculation increases, more complicated and complicated small-scale discrete devices have to be taken, which makes the reliability and maintainability of the system difficult to guarantee. In addition, the naked eye and the instrument have different feelings of distinguishing the brightness level difference, the naked eye is sensitive to the low brightness level difference, and the high brightness level difference cannot be clearly distinguished. This requires non-linear visual correction of the LED light-emitting device, compressing the low-luminance level difference, and expanding the high-luminance level difference, so that the actual gray level difference of the display conforms to the physiological sensation of the naked eye. This method will increase the difficulty and computation of the operation, and the circuit design will be more complicated.
In order to solve the above two problems, improve the display effect, reduce the design difficulty, and ensure the reliability and maintainability of the system, Jin Canal Company began to design the ultra-large-scale integrated chip from 1998. The integrated density of the chip is 80,000 gates, designed in hardware description language, abandoning the use of small-scale integrated devices, adding a lot of complex logic operations. This achievement of Golden Canal Company has cleared the above two technical obstacles and greatly improved the performance of the system.
Jin Canal 256-level grayscale super-integrated video display control system adopts the centralized control design idea, and uses the unique "8421 coded data control flow" control scheme to design, which greatly improves the accuracy and stability of the led display control part. Reliability, through a large number of complex visual correction operations, to improve the visual color gray level. The 256-level gray-scale led display has great improvements in brightness, excessive color smoothness, contrast, etc., and at the same time, various functions such as arbitrarily splicing, hot plugging, anti-static, and the like are added. These have greatly met the requirement that the LED display is a semi-permanent electronic product. In this way, production, installation, maintenance, and upgrades are all made easy. 90% of the control process is concentrated on the main control system, and the main body of the display has only basic drive circuit, and there is no complicated control circuit, which increases the reliability and maintainability of the whole system and greatly reduces the control line. The cost of the LED screen reduces the hardware cost.