Shaoxing Xinshan Science Technology Co.,Ltd
Address: Dongfangyimai, No. 2, Pujiang Road, Shaoxing, China
LED has a range of advantages such as high brightness, low working power, small power consumption, simple drive, long life, shock resistance and stable performance, etc., which are widely used in the world of screen. LED displays have been booming globally since the late 1980s. After entering the new century, the LED display technology and the industry has made great development, as one of the important modern information release media, LED display in securities trading, financial, transportation, sports, advertising, and other fields is widely used. With the process of social informatization, LED display has become more and more widely used in the field of information display.
How leds work
2.1 basic principle of LED device luminescence
LED (LED) is a special device that turns electric energy into a light energy. When the current passes through it, visible light can be produced.
LED mainly consists of PN junction chip, electrode and optical system. Luminescence is a phenomenon of energy conversion. When the system is stimulated, it can transition from stable low energy state to unstable high energy state. When the system is returned to a stable low energy state by unstable high energy state, the energy difference is radiated out in the form of light, which produces the luminous imagination. When after the forward voltage on the PN junction, the hole injection to N area of P area, electronic injection to P, N area after injected electrons and holes to meet each other to produce composite, the minority carrier injection and compound of online radiate and shine.
2.2 LED devices drive.
The luminescence mechanism of LED devices can be seen that when the forward voltage is applied to the LED device, the forward current of the moving device makes it glow. Therefore, the driver of the LED is to put the PN junction in the positive bias, and in order to control its luminous intensity, the adjustment of forward current is also addressed. The specific driving mode is dc drive, constant current drive, pulse drive and scanning drive, etc.
2.3 principle of LED display screen.
According to the LED display is a new kind of media, it is the use of LED lattice modules or pixel units composed of a flat screen, with high luminous efficiency, long service life, strong environment adaptability, cost-effective, flexible configuration, rich colors, etc. The dot matrix takes the computer as the processing control center, and the electronic screen corresponds to a certain area of the computer monitor window, displaying the content in real time synchronization. Sometimes the control system can also adjust the animation effect of the display screen, the color brightness of the display, etc.
2.4 classification of LED display screens.
LED display categories are complex and many classification methods.
According to the number of base color, it can be divided into monochrome screen, double base color screen and full color screen. The single base color display refers to a single color (red or green). The dual base color screen refers to red and green and green, with a grayscale of 256, showing 65536 colors. Full-color display refers to red, green, and blue, and 256 grayscale full-color display, which can show more than 16 million colors.
The display device is divided into LED digital display, LED lattice graphics display, LED video display screen. LED digital display device is a 7-segment digital tube that is suitable for making clock screen, interest rate screen, display digital display. The display device of an LED display screen is a lattice of light emitting diodes, which are composed of many uniformly spaced leds, which are suitable for displaying text and image information. The display device of LED video display is composed of many light-emitting diodes, which can display video, animation and other video files.
The site is divided into LED interior screen, LED outdoor screen and on-board LED screen. LED indoor screen lighting point is small, the display area generally a few to a dozen square meters; LED outdoor screen area is generally tens of square meters to a few hundred square meters, the brightness is high, can work in the sunlight, have the protection of wind, waterproof, waterproof function.
3. Technical factors that affect the display effect of LED display
LED display technology including the semiconductor optoelectronic technology, electronic circuit technology, integrated circuit technology, image information processing technology, information transmission technology, computer network technology, as well as the electronic product manufacturing and electronic product installation engineering related technologies. The display color, gray level, contrast, refresh frequency and other technical indexes of LED display directly affect the display effect of full-color LED display.
3.1 display color, brightness and perspective.
The rapid development of the basic semiconductor industry has led to the improvement of light-emitting diode manufacturing materials and manufacturing processes, making leds a quantum leap in color and brightness. High brightness blue and pure green leds have been industrialized and applied. At present, the LED display has been able to meet the environment inside and outside the monochrome, double color and full color display requirements, and the four elements of the red LED devices and high brightness blue, pure green LED devices widely used in outdoor display screen.
The brightness and Angle of the LED display are highly correlated, and have a great relationship with the resolution of the display screen. It is difficult to evaluate one of them simply. Using the LED device with a watch, the display can get a better view and brightness. It is now used in high density and full-color indoor display.
3.2 gray scale.
Grayscale is the level of brightness that can be distinguished from the darkest to the brightest in the single base color of the LED display. The higher the gray level of the LED display, the richer the color and the more colorful the color. Conversely, the display color is single, change is simple. The gradation of gray level can greatly enhance the color depth, so that the display level of image color increases geometrically.
Contrast is one of the key factors that affect the visual effect. Generally speaking, the higher the contrast, the clearer the image and the more vivid colors. High contrast is helpful in the clarity, detail, and gray level of the image. In some large black-and-white contrast text and video display, high contrast LED display has advantages in black and white contrast, clarity, integrity and so on. Contrast is more important to the dynamic video display effect. Because of the fast and dark conversion of the dynamic images, the higher the contrast is, the easier the human eye can distinguish the transformation process.
3.4 refresh frequency.
The refresh rate is the number of times the LED display is repeated per second. Full color display screen refresh rate is low, the image will appear flicker phenomenon, especially in video impact equipment shooting, the flicker phenomenon is obvious. Therefore, we should improve the refresh rate of LED display as much as possible.
4. Development trend of LED display screen.
The LED electronic display screen display to a higher brightness, higher resistance to climate, higher luminous uniformity, higher reliability, full color, multimedia direction development, the operation of the system, operation and maintenance is to develop in the direction of integration, network, intelligence. The 21st century display technology will be the era of the tablet display, LED display screen as one of the leading products will have greater development.
4.1 the resolution increases.
Indoor LED display screens are getting smaller and smaller and more pixels, making the display more resolution. Meanwhile, outdoor displays are getting bigger and bigger.
4.2 the adoption of new process and new methods.
According to the characteristics of the LED products, in the process of production of LED products, SMT, plug-in, welding and other important link, it is best to use the machine production mode (including plug-in LED by machines) driver board design, will drive IC's power supply 5 v logic is separated from the LED luminous power supply independent design, such not only can reduce the fever of driver IC, but also can reduce the LED light-emitting diodes (leds) fever.
4.3 total control system upgrade.
LED display of the control system will be a lot of LED control system integration, not only powerful, and the operating interface is very simple, the end user to operate simple, do not need to conduct more unnecessary operation, make it more humane; In the lattice structure control module of the pixel, to further improve or improve, point by point detection and related protection also need to supplement and perfect functions, such as technical parameters set part, we should make it a standardized set of parameters, change the present set by the client to set unreasonable or disorderly situation, reduce the use of the user.
The pattern of industrial development has changed.
In LED display industry, before the generation of a new product is mainly rely on their own production equipment and processing capacity can be implemented as the benchmark, a lot of good design or ideas, enterprise due to the limitation of their own conditions, had to give up. In the future, a good idea or a new product will be accomplished more with the combination of upstream and downstream enterprises. This will not only reduce the risk of new product development and investment, significantly reduce the cost of new products, but also accelerate the development of new products, thus expanding the market of products.