After several years of development, LED display screens seem to be a mature industry at first glance. In fact, both domestic and foreign manufacturers still have a long way to go, especially for outdoor large screens. After two years of operation, most of the products have It is difficult to maintain within the user’s expectations.
Why is this so?
1.First of all, there is a big misunderstanding. Most people think that LED and IC, the main materials of the screen, have a lifespan of 100,000 hours. They operate at 365 days/year and 24 hours/day. The service life is more than 11 years, so most customers Only care about using well-known LEDs and ICs. In fact, these two are only necessary conditions, not sufficient conditions, because the reasonable use of red, green, and blue lamps is more important to the display screen. For lamps of different colors, it is necessary to make them work in the best condition. A good display will be even more important. The reasonable adjustment of IC also helps to overcome the unreasonable wiring problem of PCB. It’s like a car with a good engine and circuit control does not necessarily become a good car. The key factor here is this:
Because LEDs and ICs are semiconductor devices, they are critical to the environmental conditions, preferably at room temperature around 25°C, and their working mechanism is the best. But in fact, a large outdoor screen will be used in different temperature environments, which may be above 60°C in summer and below -20°C in winter. When the manufacturer produces products, the test condition is 25℃, and different products are classified into different grades. The actual operating conditions are 60℃ or -20℃. At this time, the working efficiency and performance of LED and IC are inconsistent, which may originally belong to the first grade. The screen will become multi-speed, the brightness will be inconsistent, and the screen will naturally become blurred.
This is because under different temperature conditions, the brightness attenuation and decline of the red, green, and blue lights are different. At 25°C, the white balance is normal, but at 60°C, the three colors of LEDs The brightness of the screen has been reduced, and the attenuation value is inconsistent, so the brightness of the whole screen will be reduced and the color cast phenomenon will occur, and the quality of the whole screen will be reduced. And IC? The operating temperature range of IC is -40℃—85℃. The temperature inside the box increases due to the high outside temperature. If the temperature inside the box exceeds 85°C, the IC will work unstable due to the high temperature, or the temperature drift will cause the current between channels or the difference between chips to be too large. Causes the screen to flower.
2. LED display power is also very important. Because the power supply has different working stability, output voltage value and load capacity under different temperature conditions, because it is responsible for the logistics support, its support ability directly affects the quality of the screen.
3.The design of the LED cabinet is also very important for the display screen. On the one hand, it has a circuit protection function, and on the other hand, it is a safety function. At the same time, it also has a dust-proof and waterproof function. But the more important thing is whether the design of the thermal circuit system for ventilation and heat dissipation is good. With the extension of the boot time and the increase of the outside temperature, the thermal drift of the components will increase, which will cause the image quality to deteriorate.
These factors are all interrelated, and will affect the quality and life of the display. Therefore, when selecting screens, customers must also observe and analyze them thoroughly and make correct judgments.
The impact of temperature on the large screen is not only that. Assume that the customer has purchased a large screen with a width of 10 meters and a height of 6 meters (60 square meters). Although the total area is not large, the internal composition is each unit box. The temperature is not necessarily balanced, and the temperature in the cabinet is also affected by air convection and the temperature is inconsistent, resulting in different temperatures between the unit cabinets or inside the unit cabinets, resulting in inconsistent working efficiency of semiconductor devices, which manifests as LED lights. The brightness is inconsistent, and it looks like a “flower” screen. Don’t underestimate the outdoor temperature. Just think about the example of boiled eggs in the car in summer. What’s more, the LED display still has to illuminate under the sun exposure in summer. (The emitted light must be stronger than the sun’s light to be effective), its luminescence will inevitably generate heat, these are all influencing factors.
It is not only fragile and delicate semiconductor devices such as LEDs and ICs that fight against hot and cold temperatures, but also solid ABS, masks, iron boxes, connectors, and various soldering points. The masks are exposed to the sun and wet after the rain. Under the multiple impacts of air, some deformations will be caused by up to 2-3mm. In addition, UV radiation will also change the color of the mask plate. In this way, under various climate changes a year, the mask plate itself seen by the audience will change color. Spot plate, deformation will block the luminous angle of the luminous tube and produce dark areas; deformation will also affect the curvature of the PCB board, resulting in weak solder joints, resulting in virtual soldering, which makes the LED light up and off. In addition, due to the moisture and oxidation of the air, the oxidized contact surface of the connector is reduced. With the subtle effects of vibration and deformation, the micron-level plating of the connector does not form a close contact, which causes the signal or power supply to be interrupted, and the large screen fails.
Deformation and mechanical fatigue will also affect the iron box and the outer frame, resulting in unevenness of the screen, the module and the iron box cannot fit tightly, and some other consequences such as water leakage.
Therefore, to choose a good large screen, you must choose a good lamp in the first line, durable and adaptable, and must not be underestimated in the assessment of other materials and processes. Just like a car, a repair shop of several people can also be pieced together. A car, a factory of tens of thousands of people is also assembling a car, but the number of kilometers and the guarantee factor of the car should be far different. The waterproof and anti-deformation, processing technology of the outdoor screen is the same as that of the key accessories.
In addition to considering the quality of major components such as LEDs and ICs, pre-communication with the seller is also very important. It not only directly affects the quality, success or failure of the entire project, but also often allows users to allocate resources more reasonably, avoid unnecessary waste, loss and hidden dangers, and even increase considerable profits.
Manufacturers should also take the initiative to provide users with simulation solutions or suggestions on actual needs and operability, etc., to help customers analyze and plan rationally, and make the most cost-effective solution in order to become a reliable partner for users. The communication items generally include the following points:
1.be clear about your needs, investment budget and the best expected effect;
2.Indicate the needs of the project and the future development plan in detail, and ask the seller to provide the best implementation plan, even the expandable functions of the project and the expansion of the budget and plan, so as to avoid unnecessary problems caused by the project’s unsuitability for future development needs Waste of resources;
3.Provide or require the manufacturer to analyze data on the installation and application environment of the project, predict and propose preventive and resolution measures for possible incidents, and then make a comprehensive assessment of the entire project plan;
4.Different LED production processes, screen assembly processes, and installation technology experience will directly affect the construction period, cost, safety performance, display effect and quality, service life and maintenance costs of the entire project. Therefore, it must be understood from the manufacturer or multiple aspects beforehand. Compare the performance characteristics of all aspects of products and projects, and choose the most suitable plan for your needs;
5.To understand the strength, integrity, service content and quality of the manufacturer, these are the basis and guarantee for a good and long-term cooperation in the project.
What are the heat dissipation methods for indoor high-definition LED displays?
/in News /by creuviewElectronic products will generate more or less heat during operation. If it is very demanding on the environment, then heat dissipation is required. As a professional LED display manufacturer, let us introduce to you What are the heat dissipation methods for indoor high-definition LED displays?
Physical heat dissipation method: fan heat dissipation, which is a relatively common method at present, which has low cost and good effect.
Air fluid mechanics and the shape of the lamp housing can be used to create convective air. This is a cost-intensive method of heat dissipation.
Surface radiation heat dissipation treatment method, the surface of the lamp housing is treated with radiation heat, and the simpler is to apply radiant heat dissipation paint, which can take the heat away from the surface of the lamp housing by radiation.
The thermally conductive plastic shell is filled with thermally conductive material when the plastic shell is injection molded, so as to increase the thermal conductivity and heat dissipation capacity of the plastic shell.
An air conditioner is installed inside the outdoor LED display body to dissipate heat. This method is simple and quick, but the disadvantage is that the cost is high.
What are the precautions for the daily maintenance of outdoor full-color LED screens?
/in News /by creuviewOutdoor LED display has the advantages of good stability, low power consumption, and wide radiation range. It is the most suitable product for outdoor information dissemination. However, in the long-term use process, outdoor full-color LED displays will inevitably cause various failures due to factors such as pollution, looseness, vibration, heat, and environmental temperature changes, which will affect the normal use of the LED display, and even cause serious accidents. Therefore, regular maintenance is essential for outdoor full-color LED displays. So what does the daily maintenance of outdoor full-color LED display mainly do?
1. Daily inspection
“Daily inspection” is to conduct daily inspections and inspections of related display equipment, and to find hidden dangers to deal with them safely as soon as possible. Generally include the following four aspects:
(1) Reinforcement inspection of internal components and steel frame structure: In the case of natural disasters such as weather deterioration, it is necessary to check the stability and safety of each component of the screen body, especially the various parts of the steel structure, if any The problem should be dealt with in a timely manner.
In addition, the full-color LED display is a high-power-consuming device. After a long period of operation, due to multiple start-stops and operations, the wiring terminals of the power supply part will become loose due to cold and heat, and the contact will be weak, forming a virtual connection. It will heat up and even ignite the plastic components next to it. The signal wiring terminals will also become loose due to changes in the ambient temperature, and moisture erosion will lead to poor contact, which will lead to equipment failure. Therefore, the LED display connector must be tightened regularly. When adjusting the fasteners, the force should be even and appropriate to ensure firmness and effectiveness.
(2) Inspection of lightning protection facilities: Regular inspections of lightning rods and grounding lines. The facilities should be tested after thunderstorms, and if damaged, they must be replaced in time.
(3) Inspection of the control system of the LED large screen: Regularly check the reliability of the system to ensure its normal operation; all circuits and equipment of the large screen should also be checked regularly to avoid accidents.
(4) Inspection of the power supply system of the screen body: First, check whether the line connection in the distribution box is rusty or loose. For safety, the grounding of the electric box must be normal, and the power supply line must be checked regularly to avoid line damage.
Second, the display screen is clean
After the led full-color screen works for a period of time, the visual effect of the display will be affected due to the influence of the external environment. At this time, we can visually inspect and inspect the outdoor full-color LED display in both the bright screen and the black screen state. Including: Whether the surface of the display screen is contaminated, the purpose is to remove the influence of surface dirt on the luminous characteristics; whether there are damage cracks on the surface of the display screen; whether the communication and distribution cable lines are normal; for the equipment with high protection level, although the high reliability is selected Components and connectors, but the airtightness becomes a key factor. Therefore, it is necessary to regularly check the integrity of the seal; for the outdoor screen steel structure, check the surface paint and rust; for the outdoor screen surface pollution is particularly serious, but also Clean the display surface.
Full-color LED display cleaning is a high-altitude operation and requires a professional cleaning team. The cleaning operation adopts high-altitude sling method (commonly known as spider man) or adopts hanging blue, equipped with professional cleaning equipment. The cleaning staff chooses different cleaning agents according to different dirt on the screen for targeted cleaning, so as to ensure that the led tube is not damaged Complete the cleaning of the LED display screen under the premise of the mask and face mask.
Two points need to be paid attention to during cleaning preparation:
1. Before cleaning, disconnect the power cord.
Second, the choice of cleaning fluid, cleaning fluid generally includes electrolyte, high-purity distilled water, antistatic fluid, etc., to choose good quality, in order to effectively clean the dust and other stains on the full-color LED screen.
Cleaning and maintenance are divided into three steps:
The first step: vacuuming. First suck and sweep away the dirt and dust on the surface of the display mask.
The second step: wet washing. Be careful not to spray the lotion directly on the screen, but spray a little cleaning liquid on the cleaning cloth, and then gently wipe in the same direction. You can also use the soft brush on the vacuum cleaner to scrub the lamp mask to clean the dirt.
The third step: drying. Use a vacuum cleaner to absorb the water marks left after wet washing to ensure that the display mask is clean and dust-free.
Do you know the six major directions for the future development of LED displays?
/in News /by creuview1.Development towards energy saving
LED (semiconductor light-emitting diode) itself is very energy-saving, its characteristics are: high luminous efficiency, long life, easy control, maintenance-free; it is a new generation of solid cold light source, light color is soft, colorful, colorful, low loss , Low energy consumption, is a green and environmentally friendly product. But when it is made into an LED display, the power consumption is not small. The working voltage of the LED is generally 3.2V, and the maximum working current is 0.02A, which means that the maximum power consumption is 0.06W. However, large LED screens are large screens, which require a lot of points. Take the outdoor P16 display as an example: there are 3906 dots per square meter, and one dot has three RGB lights, then the power consumption calculation formula for one square meter is 3906 (dots) × 3 (lights) × 0.02 (A) × 5(V)=1172W (maximum power consumption, calculated according to the entire screen), the outdoor screen is at least tens of square meters, or even hundreds of square meters, then the total power consumption is very large. Therefore, reducing the power consumption of the LED display and realizing real energy saving are definitely the most important development direction of the LED display.
Second, develop towards lightness
At present, the most manufactured product in the industry is the iron box screen. The light screen weighs more than 50 kilograms per square meter, plus the weight of the steel structure, and the overall weight is very heavy. Even if it is a small and medium-sized project of tens of square meters, the total weight must be in tons. In this way, many floors of buildings are difficult to withstand such heavy attachments, and the load-bearing balance of the building and the pressure of the foundation are not easy to accept. Therefore, lightness is also the development direction of large LED screens.
Third, develop in the direction of thin and transparent
The commonly used electronic products in our lives, TV sets are becoming thinner and thinner, many mobile phones also use ultra-thin as a product highlight, and computer monitors are also developing in a thinner direction. The product becomes thinner and the weight is correspondingly lighter, which makes it easier to transport and to assemble the display screen. Large LED screens must also keep up with the mainstream of the era of electronic products. Let’s talk about “permeable”. “Permeable” refers to both air and light. If the large LED screen is installed on the top of a high-rise building, then air permeability is very important. The greater the air permeability, the smaller the wind resistance, the stronger the wind resistance, and the greater the protection of the product. If the LED display is installed on the side of a high-rise building, then the product can transmit light and will not affect the indoor lighting. Otherwise, after the product is installed, it will become a dead wall, making the room as dark during the day as at night. In summary, light transmission is also the development direction of large LED screens.
Fourth, develop in the direction of patent protection
From the perspective of global LED patent status, as far as technology is concerned, LED has the characteristics of high technical bottleneck but low entry barrier. The initial investment amount is small and the capital threshold is not high. In order to maintain technological competitiveness and reduce the risk of technological spillover, patents are the best way to protect. The patent barrier is the main means for the first to enter manufacturers to avoid competition. Therefore, patents have become an important issue that cannot be avoided in the development process of the LED industry, but the entire industry has not paid much attention to it. After the start of the LED display industry, there was basically no adjustment and development, and it directly entered a stage of fierce competition. Everyone was busy fighting for the market and expanding the scale, and hardly spent much energy on product research and development, and had not considered knowledge. Property rights are protected, and some new technologies have not been applied for patents in time. As the industry gradually matures, regulates, and protects one’s intellectual property rights and intangible assets by applying for patents is also the inevitable development direction of the LED large screen industry.
Fifth, develop in the direction of fast and accurate splicing
This is mainly for the LED rental display. Lease is characterized by frequent disassembly and assembly to meet temporary needs, so the display cabinets must be able to be spliced quickly and accurately. Just like an outdoor temporary concert, you need to rent a background display of about 50 square meters, and the decision to use a display may be installed two days before the concert. In view of this situation, if the products cannot be spliced quickly and accurately, there will be no way to meet the requirements of the site. Even if it is a fixed installation, this requirement is also required, otherwise it will increase labor costs, affect the flatness of the large screen, and thus affect the display effect. Therefore, fast and accurate installation is also the development direction of LED display.
6.Development towards standardization
At the beginning of this century, huge market demand made large LED screen companies sprung up. Almost overnight, thousands of LED display companies appeared on this magical land in Shenzhen. At the beginning of the establishment of the new enterprise, there will be products to display and sell immediately. Independent research and development of new products has a large investment and a slow speed, so everyone is trying to take shortcuts, sloppy designs, and mutual plagiarism have become a common problem at this stage of the industry. It is not just that the products between companies have different dimensions, mounting holes, etc., even their internal products are also uneven. The mounting fixing plates, hole positions, and screw specifications of the same type of product are not universal. This pair of parts Procurement, material preparation, after-sales service, etc. cause great inconvenience. Therefore, the standardization of LED large-screen products is also an inevitable trend.
How to make the LED display more high-definition
/in News /by creuviewThe led display has received widespread attention since its birth. With the continuous advancement of installation technology in recent years, it has been recognized and applied in various industries. The production and maintenance of led displays also require professional knowledge. How to achieve high-definition display?
To achieve high-definition display, there must be four factors: one is that the film source requires full high-definition; the second is that the display needs to support full high-definition; the third is to reduce the dot pitch of the led display; the fourth is the combination of the led display and the video processor. At present, the LED full-color display is also moving towards a higher definition display.
1. Improving the contrast of the LED full-color display. Contrast is one of the key factors that affect the visual effect. Generally speaking, the higher the contrast, the clearer the image and the brighter the color. High contrast is very helpful for image clarity, detail performance, and gray level performance. In some text and video displays with large black-and-white contrast, high-contrast full-color LED displays have advantages in black-and-white contrast, clarity, and integrity. Contrast has a greater impact on the dynamic video display effect. Because the light-dark transition in the dynamic image is faster, the higher the contrast, the easier it is for human eyes to distinguish such a conversion process. In fact, the contrast improvement of LED full-color screen is mainly to increase the brightness of full-color LED display and reduce the reflectivity of the screen surface. However, the brightness is not as high as possible, too high, but it will be counterproductive, not only will affect the LED display Lifespan will also cause light pollution. Light pollution has become a hot topic now, too high brightness will have an impact on the environment and people. Full-color LED display LED panels and LED light-emitting tubes undergo special processing, which can reduce the reflectivity of the LED panel and increase the contrast of the full-color LED display.
2. Increase the gray level of the full-color LED display; the gray level refers to the number of brightness levels that can be distinguished from the darkest to the brightest in the brightness of the single primary color of the full-color LED display. The higher the gray level of the full-color LED display , The richer the color, the brighter the color; on the contrary, the display color is single and the change is simple. The increase of the gray level can greatly increase the color depth, making the display level of the image color increase geometrically. The LED gray scale control level is 10bit~16bit, making the image level resolution details and display effect of high-end display products reach the world’s advanced level. With the development of hardware technology, LED gray scale will continue to develop to higher control accuracy.
3. Reducing the dot pitch of the full-color LED display and reducing the dot pitch of the full-color LED display can improve its clarity. The smaller the dot pitch of the full-color LED display, the more delicate the screen display. However, mature technology must be the core support for this. The input cost is relatively large, and the price of the full-color LED display produced is also high. However, the market is also developing towards small-pitch LED display.
4. The LED full-color display screen is combined with the video processor. The LED video processor can use advanced algorithms to modify signals with poor image quality, and perform a series of processing such as deinterlacing, edge sharpening, motion compensation, etc., to enhance the image The details to improve the picture quality. The image scaling algorithm of the video processor is used to ensure that the sharpness and gray level of the image are maintained to the greatest extent after the video image is scaled. In addition, the video processor is also required to have a wealth of image adjustment options and adjustment effects to process image brightness, contrast, and grayscale to ensure that the screen outputs a soft and clear picture.
What is the viewing angle of a full-color LED display?
/in News /by creuviewWe know that televisions, computer screens and LCD screens all have viewing angles, and this statement also exists in the field of LED screens. What is the viewing angle of a full-color LED display? What factors does the viewing angle have to do with? With this question, let’s learn together:
1.Definition of viewing angle of full-color LED display
The viewing angle of a full-color LED display refers to the angle at which users can clearly observe all content on the screen from different directions. The viewing angle can also be understood as the maximum or minimum angle at which the screen can be seen clearly. And the viewing angle is a reference value. The viewing angle of the LED full-color display includes two indicators, horizontal and vertical.
For example, usually full-color LED display, the technical parameters have this description: Viewing angle: 140°/140°; refers to the maximum viewing angle of 140°, the maximum horizontal and vertical viewing angle is 140°, after more than 140 degrees , The viewing effect is poor or there are blind spots.
The horizontal viewing angle is based on the vertical normal of the full-color LED display (ie the vertical imaginary line in the middle of the LED display), and it can still be seen normally at a certain angle to the left or right of the normal. For displaying images, this angle range is the horizontal viewing angle of the LED full-color display; similarly, if the horizontal normal is taken as the standard, the vertical viewing angle is called the vertical viewing angle. Generally speaking, the viewing angle is based on the contrast change as a reference standard. When the viewing angle increases, the contrast of the displayed image seen at this position will decrease, and when the angle increases to a certain extent, the contrast decreases to 10:1, this angle is the maximum viewing angle of the full-color LED display.
2.Factors affecting the viewing angle of a full-color LED display
The larger the full-color LED screen can be seen by the audience, the better, so the larger the viewing angle, the better. However, the size of the viewing angle is mainly determined by the die packaging method, so we must carefully consider when packaging the die.
In addition, the viewing angle has a lot to do with the viewing angle and distance. At present, most LED display manufacturers have the same angle. If you customize the angle according to the actual situation, the cost will be very high. In addition, with the same chip, the greater the angle, the lower the brightness of the full-color LED screen.
What is the reason for the frequent tripping of the led display distribution box?
/in News /by creuviewThere are four main reasons for the frequent job-hopping of general full-color LED display power distribution cabinets:
1.The layout of the leakage protector is unreasonable: due to the particularity of the LED full-color display installation site and the inevitable misoperation and refusal of the leakage protector itself, and the leakage protector is not carried out according to the actual electricity consumption. The arrangement caused frequent tripping of the total leakage protector.
LED full-color display solution: In addition to strengthening management in the face of this situation, it is mainly necessary to rationally arrange the leakage protector from a technical point of view and according to the actual situation.
2.There is no effective secondary or tertiary leakage protection within the scope of protection: the final leakage protector in the switch box is the main protection of the electrical equipment, because there are many metal conductors in the LED display, wire connectors In many cases, if the wire insulation is not very good, it will cause frequent leakage; some sockets are added, and in many cases, leakage protectors are not installed, which often causes leakage.
LED full-color display solution: Determine and effectively implement the secondary or tertiary leakage protection mode to effectively reduce the frequent tripping of the leakage protector.
3.The leakage protector itself has certain limitations (the three-phase electricity is unbalanced): the current leakage protector, whether electromagnetic or electronic, uses a magnetic induction voltage transformer to pick up the leakage current in the main circuit of the electrical equipment , It is impossible for three-phase or three-phase four-wire to be completely balanced in the magnetic ring.
The three-phase power load of the LED full-color display cannot be completely balanced. Under high current or high overvoltage, a certain electromotive force will be induced in the magnetic ring with high permeability, which is so large To a certain extent, it will cause the leakage protector to trip.
4.The selection of leakage protector is unreasonable
The rated leakage action current used in the switch box exceeds 30mA or is more than twice the rated current of the electrical equipment, or the leakage protector with delay type is selected, due to the increase or protection of the rated leakage action current When the sensitivity drops and a leakage fault occurs, the last-stage leakage protector does not operate, and the upper-stage leakage protector may operate.
LED full-color display solution: The starting current when powering on the LED full-color display is often relatively large, and this large current may trip the leakage protector. Therefore, the cabinets of the display should be electrified in batches as much as possible. In addition, in general, an electromagnetic leakage protector that is not sensitive to surge overvoltage and overcurrent should be selected; or an electronic leakage protector that is 1.5 to 2 times larger than the rated current, but as the final leakage protection, rated leakage action The current should not be greater than 30mA.
In fact, the most fundamental reason is the selection of leakage protectors for LED display screens and the inadequate protection measures.
Three main points that must be clear when choosing a small-pitch LED display
/in News /by creuviewIn the field of LED display in 2017, the small-pitch LED display has become a well-deserved star product, and its market application scope is expanding rapidly. For users, although they are not unfamiliar with small spacing under the promotion of manufacturers, they are still not sure about how to choose products that suit their requirements. Then, when purchasing small-pitch LED products, what are the key points that users should pay attention to in order to maximize the investment benefits while meeting the needs of use?
1.”Low brightness and high gray” is the premise:
As a display terminal with a small-pitch LED display, the first thing to ensure is the comfort of viewing. Therefore, when purchasing, the primary concern is the brightness issue. Relevant studies have shown that, in terms of human eye sensitivity, LED as an active light-emitting source, its brightness is twice that of passive light-emitting sources (projectors and liquid crystal displays), and to ensure the comfort of human eyes, the small-pitch LED screen The brightness range can only be between 100 cd/m2-300 cd/m2.
However, in traditional LED display technology, reducing the brightness of the screen will cause the loss of grayscale, and the loss of grayscale will directly affect the picture quality. Therefore, an important criterion for high-quality small-pitch LED displays is to achieve ” “Low brightness and high gray” technical indicators
In actual purchase, users can follow the principle of “the more brightness levels that human eyes can recognize, the better”. The brightness level refers to the brightness level of the image that the human eye can distinguish from the darkest to the whitest. The more the recognized brightness level, the larger the color gamut space of the display screen, and the greater the potential for displaying rich colors.
2.Select the point spacing and pay attention to the balance between “effect and technology”
Compared with the traditional LED screen, the outstanding feature of the small-pitch LED display is the smaller dot pitch. In practical applications, the smaller the dot pitch, the higher the pixel density, the more information capacity per unit area can be displayed at one time, and the closer the distance suitable for viewing. On the contrary, the longer the distance suitable for viewing. Many users naturally think that the smaller the dot pitch of the product, the better. However, this is not the case.
Conventional LED screens want to achieve the best visual effects and have the best viewing distance. The same is true for small-pitch LED screens. Users can make simple calculations through the best viewing distance=dot pitch/0.3~0.8. For example, the best viewing distance of the P2 small-pitch LED display is about 6 meters away.
We know that the smaller the dot pitch, the higher the cost of the small-pitch LED screen. Therefore, in actual purchase, users must comprehensively consider their own cost, demand, application range and other factors.
3. Choose the resolution, pay attention to the match with the “front-end signal transmission equipment”
The smaller the dot pitch of the small-pitch LED screen, the higher the resolution, and the higher the picture definition. In actual operation, users want to build the best small-pitch LED display system. While paying attention to the resolution of the screen itself, they must also consider the combination of it and the front-end signal transmission product.
For example, in security monitoring applications, the front-end monitoring system generally includes video signals in D1, H.264, 720P, 1080I, 1080P and other formats. However, not all small-pitch LED screens on the market can support the above. Therefore, in order to avoid waste of resources, users must choose according to their needs when purchasing small-pitch LED screens, and avoid blindly following the trend.
At present, small-pitch LED products have been widely used in TV studios, power system monitoring centers, aerospace command centers, military command centers, government halls, urban monitoring centers, video conference rooms, dispatch rooms, airports, train stations, hotels, and large Medium-sized enterprises and other occasions.
How to choose an LED display?
/in News /by creuviewAfter several years of development, LED display screens seem to be a mature industry at first glance. In fact, both domestic and foreign manufacturers still have a long way to go, especially for outdoor large screens. After two years of operation, most of the products have It is difficult to maintain within the user’s expectations.
Why is this so?
1.First of all, there is a big misunderstanding. Most people think that LED and IC, the main materials of the screen, have a lifespan of 100,000 hours. They operate at 365 days/year and 24 hours/day. The service life is more than 11 years, so most customers Only care about using well-known LEDs and ICs. In fact, these two are only necessary conditions, not sufficient conditions, because the reasonable use of red, green, and blue lamps is more important to the display screen. For lamps of different colors, it is necessary to make them work in the best condition. A good display will be even more important. The reasonable adjustment of IC also helps to overcome the unreasonable wiring problem of PCB. It’s like a car with a good engine and circuit control does not necessarily become a good car. The key factor here is this:
Because LEDs and ICs are semiconductor devices, they are critical to the environmental conditions, preferably at room temperature around 25°C, and their working mechanism is the best. But in fact, a large outdoor screen will be used in different temperature environments, which may be above 60°C in summer and below -20°C in winter. When the manufacturer produces products, the test condition is 25℃, and different products are classified into different grades. The actual operating conditions are 60℃ or -20℃. At this time, the working efficiency and performance of LED and IC are inconsistent, which may originally belong to the first grade. The screen will become multi-speed, the brightness will be inconsistent, and the screen will naturally become blurred.
This is because under different temperature conditions, the brightness attenuation and decline of the red, green, and blue lights are different. At 25°C, the white balance is normal, but at 60°C, the three colors of LEDs The brightness of the screen has been reduced, and the attenuation value is inconsistent, so the brightness of the whole screen will be reduced and the color cast phenomenon will occur, and the quality of the whole screen will be reduced. And IC? The operating temperature range of IC is -40℃—85℃. The temperature inside the box increases due to the high outside temperature. If the temperature inside the box exceeds 85°C, the IC will work unstable due to the high temperature, or the temperature drift will cause the current between channels or the difference between chips to be too large. Causes the screen to flower.
2. LED display power is also very important. Because the power supply has different working stability, output voltage value and load capacity under different temperature conditions, because it is responsible for the logistics support, its support ability directly affects the quality of the screen.
3.The design of the LED cabinet is also very important for the display screen. On the one hand, it has a circuit protection function, and on the other hand, it is a safety function. At the same time, it also has a dust-proof and waterproof function. But the more important thing is whether the design of the thermal circuit system for ventilation and heat dissipation is good. With the extension of the boot time and the increase of the outside temperature, the thermal drift of the components will increase, which will cause the image quality to deteriorate.
These factors are all interrelated, and will affect the quality and life of the display. Therefore, when selecting screens, customers must also observe and analyze them thoroughly and make correct judgments.
The impact of temperature on the large screen is not only that. Assume that the customer has purchased a large screen with a width of 10 meters and a height of 6 meters (60 square meters). Although the total area is not large, the internal composition is each unit box. The temperature is not necessarily balanced, and the temperature in the cabinet is also affected by air convection and the temperature is inconsistent, resulting in different temperatures between the unit cabinets or inside the unit cabinets, resulting in inconsistent working efficiency of semiconductor devices, which manifests as LED lights. The brightness is inconsistent, and it looks like a “flower” screen. Don’t underestimate the outdoor temperature. Just think about the example of boiled eggs in the car in summer. What’s more, the LED display still has to illuminate under the sun exposure in summer. (The emitted light must be stronger than the sun’s light to be effective), its luminescence will inevitably generate heat, these are all influencing factors.
It is not only fragile and delicate semiconductor devices such as LEDs and ICs that fight against hot and cold temperatures, but also solid ABS, masks, iron boxes, connectors, and various soldering points. The masks are exposed to the sun and wet after the rain. Under the multiple impacts of air, some deformations will be caused by up to 2-3mm. In addition, UV radiation will also change the color of the mask plate. In this way, under various climate changes a year, the mask plate itself seen by the audience will change color. Spot plate, deformation will block the luminous angle of the luminous tube and produce dark areas; deformation will also affect the curvature of the PCB board, resulting in weak solder joints, resulting in virtual soldering, which makes the LED light up and off. In addition, due to the moisture and oxidation of the air, the oxidized contact surface of the connector is reduced. With the subtle effects of vibration and deformation, the micron-level plating of the connector does not form a close contact, which causes the signal or power supply to be interrupted, and the large screen fails.
Deformation and mechanical fatigue will also affect the iron box and the outer frame, resulting in unevenness of the screen, the module and the iron box cannot fit tightly, and some other consequences such as water leakage.
Therefore, to choose a good large screen, you must choose a good lamp in the first line, durable and adaptable, and must not be underestimated in the assessment of other materials and processes. Just like a car, a repair shop of several people can also be pieced together. A car, a factory of tens of thousands of people is also assembling a car, but the number of kilometers and the guarantee factor of the car should be far different. The waterproof and anti-deformation, processing technology of the outdoor screen is the same as that of the key accessories.
In addition to considering the quality of major components such as LEDs and ICs, pre-communication with the seller is also very important. It not only directly affects the quality, success or failure of the entire project, but also often allows users to allocate resources more reasonably, avoid unnecessary waste, loss and hidden dangers, and even increase considerable profits.
Manufacturers should also take the initiative to provide users with simulation solutions or suggestions on actual needs and operability, etc., to help customers analyze and plan rationally, and make the most cost-effective solution in order to become a reliable partner for users. The communication items generally include the following points:
1.be clear about your needs, investment budget and the best expected effect;
2.Indicate the needs of the project and the future development plan in detail, and ask the seller to provide the best implementation plan, even the expandable functions of the project and the expansion of the budget and plan, so as to avoid unnecessary problems caused by the project’s unsuitability for future development needs Waste of resources;
3.Provide or require the manufacturer to analyze data on the installation and application environment of the project, predict and propose preventive and resolution measures for possible incidents, and then make a comprehensive assessment of the entire project plan;
4.Different LED production processes, screen assembly processes, and installation technology experience will directly affect the construction period, cost, safety performance, display effect and quality, service life and maintenance costs of the entire project. Therefore, it must be understood from the manufacturer or multiple aspects beforehand. Compare the performance characteristics of all aspects of products and projects, and choose the most suitable plan for your needs;
5.To understand the strength, integrity, service content and quality of the manufacturer, these are the basis and guarantee for a good and long-term cooperation in the project.
Overview of LED display
/in News /by creuviewLED has the characteristics of high photoelectric conversion efficiency, low driving voltage, ease of interface with a computer, and long replacement. The size of the screen can be seamlessly spliced as needed, making LED the first choice for making flat panel displays.
Blue LED is a product that appeared in the late 1980s. The appearance of blue LED made full-color LED display possible. With the continuous decline in the price of blue LED chips, full-color LED display has gradually been applied, showing Bright prospects for the development of LED displays.
(1) Full-color-the light-emitting pixels that make up the LED display screen have three colors of red, green, and blue, and the combination of different gray levels of the three primary colors of transmission red, green and blue can better restore the colors of the natural world, with rich performance Theoretically speaking, its color reproduction ability exceeds that of TVs. Through the price drop of blue chips, the production cost of full-color screens continues to decrease, which will become the development direction of LED display screens.
(2) Video screen-Video screen means that the LED screen has a corresponding mapping relationship with the control computer display. The video screen has gray control and is displayed synchronously with the computer monitor. Therefore, it can play the animation, VCD, and connect with a special multimedia card. Play video signals with rich expressive power. The video screen cannot work without the computer. Generally, a computer controls a video screen.