1. History of LED technology development
2. Development of LED display screen
3.Application of LED display screen
4.LED displays are classified according to usage environment
5.LED displays are classified by color
6LED display screens are classified by process
7.LED displays are classified according to application scenarios
8. Six major features of LED display
9.LED display case video
1. History of LED technology development
LED is the English abbreviation of Light Emitting Diode. The unique optoelectronic properties of LED make it widely used in many fields and equipment, such as various electrical appliance remote controls, equipment indicators, LED lighting and Display etc. So how was the first LED born? Let us take a look at the development history of LED.
In 1907, scientists from the Marconi Laboratory in the UK first deduced that the semiconductor PN junction could emit light under certain conditions. This discovery laid the physical foundation for the invention of LEDs.
In 1927, Russian scientists independently produced the world’s first LED, and their research results were published in scientific magazines in Russia, Germany and the United Kingdom. In the following period, people did not realize its huge potential and application value, resulting in LED only staying at the technical level.
In 1955, physicists at Radio Corporation of America first discovered the infrared radiation of gallium arsenide (GaAs) and other semiconductor alloys and physically realized the luminescence of diodes. Since the light emitted is not visible light but infrared rays, this research result is of great significance to the development of LEDs.
In 1961, scientists at Texas Instruments (TI) discovered that gallium arsenide emits infrared radiation when a stream of electrons is applied to it. They were the first to produce infrared LEDs for commercial use and patented the invention of gallium arsenide infrared LEDs. Soon after its official commercial use, infrared LEDs were widely used in various sensors and optoelectronic equipment. For example, the functions of remote controls for various household appliances rely on infrared LEDs.
In 1962, researchers from General Electric (GE) Company in the United States invented LEDs that can emit red visible light and are known as the “father of light-emitting diodes.” At that time, LEDs could only be made by hand, and each LED cost as much as $10. In 1963, the researcher left General Electric Company in the United States and became a professor in the Department of Electrical Engineering at his alma mater, the University of Illinois, USA, further advancing the scientific research of LEDs.
In 1972, the researcher’s students followed in the footsteps of their predecessors and invented the first orange-yellow LED, which was 10 times brighter than the previous red visible light LED. This marked an important first step towards improving the luminous efficiency of LEDs. .
In the late 1970s, people had developed LEDs with red, orange, yellow, green, emerald and other colors of light, but there were still no blue and white LEDs. Although the technical level at that time could not yet realize full-color LED display, the luminous efficiency of LED had been greatly improved. In the mid-1970s, LEDs could produce green, yellow, and orange light with a luminous efficiency of 1 lumen/watt. By the mid-1980s, the use of gallium arsenide and aluminum phosphide enabled the first generation of high-brightness red, Yellow and green LEDs were born, and the luminous efficiency has reached 10 lumens/watt.
In 1993, while working at Nichia Chemical Industry Co., Ltd. in Japan, Shuji Nakamura invented blue LED using semiconductor materials gallium nitride (GaN) and steel gallium nitride (InGaN). Before the emergence of blue LEDs, LEDs could not be used in the lighting field because white light could not be synthesized through the RGB system, and the light efficiency and brightness of LEDs were not high. In 1995, Shuji Nakamura invented green LED using steel nitride. In 1998, white LED was made using red, green and blue LEDs. The successful development of green and white LEDs marks the official entry of LEDs into the lighting field, which is the most critical milestone in the development of LED lighting. Shuji Nakamura is therefore known as “the father of blue, green, and white LEDs.”
In 1996, Nichia Chemical Industry Co., Ltd. filed the earliest invention patent for white light LED in Japan, which coated a blue LED chip with YAG yellow phosphor. The blue light emitted by the chip complemented the yellow light emitted after the phosphor was activated. White light. The emergence of blue and white LEDs has broadened the application fields of LEDs and provided a technical foundation for full-color LED displays, LED lighting and other applications.
By the early 21st century, LEDs could already emit light of various colors in the visible spectrum, as well as display infrared and ultraviolet rays, and their luminous efficiency had reached more than 100 lumens/watt.
2. Development of LED display screen
With the continuous updating and development of LED production technology, people have discovered that LED, as a point light source, can be used as lighting or display screens after using a larger number of LED lamp beads at the same time. In the 1970s, the early inventions of red and yellow LEDs such as GaP and GaAsP began to be used for instrument indicators, displaying simple numbers and text, etc., becoming the earliest prototype of the development of LED displays. Due to limitations of production technology and cost, LED display technology has not been vigorously developed.
Until the early 1990s, LED semiconductor materials and production technology became increasingly mature. After Japan’s Nichia Chemical Industry Co., Ltd. invented blue LED, LED displays had the ability to display full color. Subsequently, LED display products gradually appeared and entered consumption. market. Limited by the LED display control technology, the LED display screen at that time was mainly used to display text and pictures, with low display brightness and gray scale. However, the easy scalability of the LED display screen made customers in the traditional LCD market realize that LED The display has huge development potential.
In 1996, the former Ministry of Electronics entrusted Lantong Company to formulate the “General Specifications for LED Displays”. LED displays truly became an independent industry.
The emergence of industry norms and standards accelerated the development of the LED industry. In 1998, the China Optics and Optoelectronics Industry Association established the LED Display Professional Committee. In January 2003, the China Optics and Optoelectronics Industry Association’s Light-emitting Diode Display Branch was officially established. In November 2006, it was changed to the China Optics and Optoelectronics Industry Association’s Light-emitting Diode Display Application Branch, marking the The LED industry has entered into standardized and standardized development.
Limited by LED lamp bead technology, early LED displays were mainly single-color and two-color screens, such as red and red-green two-color displays, which mostly displayed text and pictures. Single-color and two-color display screens are shown in Figure 1-1.
Around 2000, full-color LED displays based on three primary colors were put into commercial use. Due to the high brightness and rich colors of LED displays, full-color LED displays replaced the billboards used by traditional media and were installed on urban main roads and intersections. and commercial office buildings, full-color LED displays have ushered in a period of rapid development due to their excellent display effects and visual impact. The full-color LED display is shown in Figure 1-2.
3.Application of LED display screen
As a new display carrier, LED display screen is used in more and more scenarios due to its unique advantages. The mainstream application scenarios include the following.
(1) Airports, railway stations, bus stations, etc. Due to the high mobility and large number of people at the station, it has become an important place for media operators to promote advertising. As one of the best carriers for displaying advertisements and disseminating information, LED display screens have become standard equipment in modern airports and stations.
Warm reminder: Dear passengers, for the health of you and others, please actively cooperate with health code verification and temperature measurement, pay attention to queue issues, and wear a mask throughout the journey. Thank you for your cooperation.
Passengers who have purchased electronic tickets can directly enter the station with their valid identity documents for verification. Military personnel are given priority in accordance with the law, and fire and rescue personnel are given priority.
2) Stage, event site, etc. Various indoor/outdoor performing arts activities, live TV broadcasts, variety shows, etc., in order to present better stage effects, LED displays will be used as an important part of the stage effects. The gorgeous display effects and video special effects directly affect the appearance of the entire stage. Effect. The stage display is shown in Figure 1-4.
(3) Hotels, conference rooms, school classrooms, etc. In order to more vividly display promotional videos, work reports, teaching courseware, etc., LED displays are also installed in these indoor occasions to replace traditional display media, such as projectors, LED LCD screens, etc. The indoor display screen is shown in Figure 1-5.
Traffic command and dispatch center, military, power dispatch room, urban comprehensive management platform, etc. These occasions require the display of a variety of different data and the unified scheduling and management of them, so large screens are required for display. LED displays have become standard facilities in these occasions. The display screen of the traffic control and dispatch center is shown in Figure 1-6.
Urban traffic guidance, highway signs, etc. With the continuous development of population and economy, the road traffic situation in my country’s big cities has become increasingly severe. In order to display and guide vehicles in real time, more and more cities have installed LED displays on the roads. The traffic guidance display is shown in Figure 1-7
The city’s bustling intersections, commercial complexes, office buildings, park squares, etc. Due to their superior geographical locations, these locations are important occasions for advertising. The installation of LED displays activates the vitality of the installation site and becomes a landscape of the city.
4.LED displays are classified according to usage environment
1. Outdoor LED display
The outdoor LED display screen has a large area, generally ranging from a few square meters to dozens or even hundreds of square meters, with a large pixel spacing (mostly 2500~10000 pixels/m2), and a luminous brightness of 5500~8500cd/m2 (different orientations , different brightness requirements), can be used under direct sunlight, with a viewing distance of tens of meters away, and the screen body has good windproof, rainproof and lightning protection capabilities. Since the outdoor environment is relatively harsh, outdoor modules are required to have good waterproof performance. Generally, the LED module is put into the kit and then filled with glue to achieve waterproofing. Due to the large outdoor viewing distance, outdoor LED modules emit higher brightness. The outdoor LED display is shown in Figure 1-26.
2. Indoor LED display
The area of indoor LED display screens varies depending on the use environment, generally ranging from a few square meters to more than ten square meters, or even hundreds of square meters. Because they are used in indoor environments and have a close viewing distance, this type of display screen generally has an exquisite appearance, high pixel density (number of pixels per unit area), large viewing angle, short color mixing distance, light weight, high density, and the luminous brightness should not be too high. 
5.LED displays are classified by color
1. Single primary color LED display
A single-primary color LED display screen is composed of a single-primary color module, that is, each pixel is composed of only one color or one primary color LED lamp. Since LED red light has a longer wavelength and higher brightness, common single-primary color modules are basically modules with red as the primary color. Single primary color LED display is mainly used to display text information. For example, the door screen installed above the bank entrance is used to display text information such as the current bank interest rate; there is also a bar screen installed above the counter to display the function description or numbering sequence of the window.
2. Dual color LED display
The dual-primary color LED display screen is composed of dual-primary color modules, generally red and green, and can display three colors: red, green, and yellow (red and green mixed). The dual-color LED display is mainly used to display text information, and different information content is generally distinguished by color. Common applications include displaying flight information and stock information. For example, when displaying flight information, yellow displays waiting flight information, green displays flight information that is checking in, and red displays stopped flight information. Figure 1-29 shows the application scenario of dual-primary color LED display.
3. Full color LED display
The full-color LED display is composed of a three-primary color module, that is, a single pixel on the module has three lamp beads: red, green, and blue. According to the principle of the three primary colors of light, theoretically, by controlling the luminous intensity of the three-primary color LED lights, Make up any color. It can be displayed in various forms, such as text, pictures or videos. The application scenario of full-color LED display is shown in Figure 1-30. Compared with single-color LED displays and dual-color LED displays, full-color LED displays have a variety of display forms and can cover most areas of the current display industry. They are currently the most widely used display type.
6. LED display screens are classified by process
1. Direct plug-in LED display (DIP)
The LED lamp beads with two metal pins are welded through the circuit board. This method is called DIP (Dual In-line Package). The LED packaged in this way is called in-line LED, as shown in Figure 1 -31 shown. In-line LED displays are composed of in-line modules. The light sources used in this type of modules are in-line lamp beads. Their advantages are high brightness, large light angle, high cost performance and mature packaging technology. This type of lamp beads was widely used in the early days of the industry, but now it has been gradually phased out as the industry matures.
2. Surface mount LED display (SMD package)
The pins of the LED lamp beads are directly welded to the surface of the circuit board without passing through the circuit board. This method is called SMD (Surface Mount Device) packaging. LEDs packaged in this way are called surface mount LEDs, such as As shown in Figure 1-32. Surface-mounted LED displays are composed of surface-mounted modules. The light sources used in this type of modules are surface-mounted three-in-one lamp beads. The industry’s packaging technology has also been quite mature. Nowadays, surface-mounted three-in-one lamp beads are still It is the mainstream lamp bead in the industry and is widely used in various types of displays in the LED industry. Surface-mounted LED displays were born after plug-in LED displays. At the beginning, they were mostly used indoors. Later, with the maturity of high-brightness surface-mounted LED lamp bead technology, they began to be widely used outdoors.
3. Chip-on-board LED display (COB package)
Multiple lamp bead crystals are packaged on a circuit board at one time. This method is called COB (Chip on Board) packaging. LEDs packaged in this way are called chip-on-board LEDs, as shown in Figure 1-33. Show. Chip-on-board LED displays are composed of chip-on-board LED modules. It is an emerging packaging technology in the industry. It abandons the industry’s traditional lamp bead packaging method and directly fixes the light-emitting chip on the PCB substrate. This packaging process can not only make the pixel pitch of the LED display smaller, but also reduce the entire production process. Based on the maturity of the process in the future, it can greatly improve the production efficiency of the entire LED display and reduce the production cost. . Compared with plug-in LED displays and surface-mounted LED displays, chip-on-board LED displays have technical advantages such as smaller pixel pitch, anti-static, dust-proof, and waterproof.
4. Four-in-one Mini-LED display (IMD package)
Four-in-one Mini-LED is a small unit that uses four-in-one array packaging technology and uses two LED lamp beads horizontally and vertically. Each LED lamp bead is still packaged by an RGB three-color chip. It is called in the industry. This packaging method is imd (integrated Matrix Devices) packaging. Four-in-one Mini-LED is shown in Figure 1-34. A display screen composed of four-in-one Mini-LED modules is called a four-in-one Mini-LED display. This technology is an advancement in overcoming small spacing. To put it simply, SMD is a discrete device, COB is an integrated package chip, and IMD can be understood as a small integrated package for high-speed patching. Different from SMD and COB, IMD is a new generation product that integrates the advantages of two technical paths.
7.LED displays are classified according to application scenarios
1. Fixed screen
A fixed screen refers to an LED display screen that is fixedly installed at a designated location. During regular use, it does not need to be disassembled and moved after installation, so it only needs to meet the environment and viewing requirements.
2. Rental screen
Rental screens are generally used in temporary scenes such as performances, parties, and exhibitions. This type of LED display screen generally has the characteristics of frequent disassembly, high installation efficiency requirements, and strong viewing immediacy. Therefore, the rental screen has good protection, easy installation structure, and components. Easy to disassemble and assemble.
8. Six major features of LED display
The development of economy and technology is driving the rapid development of cities. Especially since 2010, LED displays can be seen in more and more occasions, such as office buildings, large shopping malls, stations, conference rooms, squares, stages, Command center, etc. The rapid development of LED display screen is enough to illustrate its value and role. So what are the advantages and characteristics of LED displays? The following mainly introduces it from 6 aspects.
(1) High brightness. The brightness of equipment such as traditional LCD screens and projectors is generally 500cd/m2, while the brightness of displays using high-brightness LED lamp beads can reach 10,000cd/m2. At such a high brightness, the LED display can display a clear picture even under direct sunlight; even if it is used continuously for a long time, its brightness will not decay more than 5% per year.
(2) High fidelity. The color gray scale of traditional display carriers is only 8 bits, that is, a brightness variation range of 256 levels. However, the gray scale of an LED display equipped with a specific control system and driver chip can reach 16 bits, or 65,536 levels, which is 256 times that of traditional display equipment. This allows the LED display to present more color details, completely restore the original effect of the display material, and make the picture more vivid and gorgeous.
(3) Infinitely expandable. Traditional LCD screens and projectors are limited in size due to technical limitations and are difficult to expand arbitrarily. The LED display screen is made up of independent boxes, which can be infinitely expanded according to the needs of the user, and can be spliced into irregular shapes to meet different display needs.
(4) Economy. The LED display screen is composed of an array of light-emitting diodes. The light-emitting diodes have the characteristics of low power consumption. When used, they only require a few milliamps of current to work normally. Comparing LED and LCD displays of the same size, the power consumption of the LED display screen is About half of the LCD display screen, the economic benefits are significant.
(5) High reliability. The operating temperature range of the LED display is -40~100℃, and the operating voltage range is 2.0~3.6V. The wide temperature range, low operating voltage, and the unique structure of the LED display make the LED lamp beads suitable for outdoor and It has high reliability in various working environments such as indoors, and can withstand the test of high temperature, severe cold, moisture, salt spray, dust, etc. all year round. Therefore, LED display screens are very suitable for various commercial purposes.
(6) Long life. There is a PN junction inside the LED. As long as a suitable forward voltage is applied to both ends of the PN junction, it will be lit. The power consumption is very small, and the luminous efficiency is high. Most of the energy is output in the form of light, so the heat generation is small. As we all know, for the aging of electronic components, the amount of heat in the working environment will directly determine the working life and aging speed of the components. The extremely small amount of heat generated by LED makes its working life reach 80,000 to 100,000 hours, which greatly reduces the later period. Maintenance costs.
9.LED display case video
Share some screen cases of LEGIDATECH
1.Outdoor P10 LED Screen to Uganda
Outdoor LED Screen Size : 5.76×3.84meters (18.88ftx12.59ft) .
Outdoor LED Screen Panel : 960x960mm (WidthxHeight )
LED Panel Material : Magnesium Alloy
LED Screen Control System : Novastar Control System .
LED Screen Controller : Novastar TB50 Media Box .
Outdoor LED Display Screen Package : Wooden Case .
Outdoor LED Display Spare Parts : LED Modules , 200W Power Supply Unit , Novastar Receiving Cards , Power cables and Signal cables etc .
2. Indoor P3.9 LED Screen to Nigeria
Indoor LED Screen Size : 4 x 3meters (12ft x 9ft) .
Indoor LED Screen Panel : 500 x 500mm (Width x Height )
LED Panel Material : aluminum
LED Screen Control System : Novastar Control System .
Product: H series Magnet LED screen
Indoor LED Display Screen Package : carton .
Indoor LED Display Spare Parts : LED Modules , 200W Power Supply Unit , Novastar Receiving Cards , Power cables and Signal cables etc .
3. Indoor church led display in South Africa
This is a sacred and solemn place. The large screen in the church is 2 meters high and 5 meters wide, and the two small screens are each 1 meter high and 2 meters wide. In this spacious and quiet space, exquisite religious images and connotative texts are played on the large screen, leading believers into the pure land of the soul. The small screen is used to display religious-related information, activities and sermons, so that every believer can have a deeper understanding of the true meaning of faith. Due to high-quality pictures and perfect sound effects, these screens have become important auxiliary tools in churches, bringing spiritual enlightenment to believers time and time again.
If anyone needs a church display screen, you can contact LEGIDATECH for free consultation on screen size and price.
4. Stage rental led display for concert
5. Stage rental led display for events-magic series
