These Four Factors Need to Be Considered in the Design Scheme of Stage LED Display Screen

Before the implementation of the stage rental LED display screen project, it is necessary to make a design scheme, especially when designing the screen body, it is necessary to consider important factors such as the display screen model, display content, installation site environment and cost, and ensure that the production process and technical indicators are suitable for the actual indoor application needs, so as to carry out reasonable design.

The sense of visual graininess mainly comes from the fact that the human eye has a certain resolution. When the two points are close to a certain extent, the human eye will not be able to distinguish them. In recent two years, with the improvement of LED display manufacturing technology and the continuous improvement of small spacing LED display body resolution, the indoor display design has been improved from the initial selection of the minimum point distance specification scheme to the selection of the appropriate point distance specification scheme.

Pixel spacing is the distance between lamp beads, for example, P3 pixel spacing is 3mm; The minimum sight distance is the distance that human eyes can't distinguish pixel particles, but this distance will damage vision if viewed for a long time; The best viewing distance is not only the comfortable distance to watch the screen, but also the clearest distance; The pixel density is the screen definition index. The larger the value, the higher the screen definition; Full HD image and video, screen 16:9 golden ratio, human vision is the best.

According to the analysis in the above table, the rental LED display screens of p1.27, p1.54, P1.6, p1.9 and p2.5 are small spacing LED display screens (the point spacing is less than 2.5mm). The minimum viewing distance and the best viewing distance are very close to the viewing requirements of large flat panel TV, and the whole screen resolution is up to 4800 2400, clearer pictures can be displayed on the same screen body, but one HD signal needs to be amplified by 3 4 times on a 12m wide screen, and two HD pictures need to be amplified by 2 times; At the same time, high-resolution display requires high-performance image processing equipment, and the overall cost of the system will be very high.

P4 and p4.8 cannot display two high-definition pictures at the same time on a 12m wide screen, which can not meet the display requirements of high-definition conference TV pictures. P3 can meet the requirements of displaying two high-definition pictures at the same time. According to the size of the display screen, P3 with high cost performance is finally selected as the display point distance of the main screen and auxiliary screen of the project, and P4 is selected as the display point distance of the monogram screen.

One factor that determines the quality of LED is the main materials, such as chip, bracket, glue (epoxy resin), gold wire, etc. the other factor is the packaging process. Pixel packaging technology is related to the color saturation, viewing angle and other display effects of the whole display screen, production cost and quality stability. It is one of the key indicators for selecting LED display screen.

The mainstream indoor LED packaging technologies mainly include in-line dip and SMD mode. The in-line module encapsulates the light-emitting tube into a square shape, and then puts the red, green and blue tubes together to make a pixel module, which is directly inserted and welded on the PCB board. The process is relatively simple, the cost is low and the defect rate is high. It is mainly used in outdoor display screens. Surface pasting refers to pasting the encapsulated light-emitting tube on the circuit board, and then processing the integrated circuit welding process into a screen body. It has good heat dissipation and uniform color, and the whole display screen can be maintained in the front, which greatly reduces the maintenance cost and difficulty; At the same time, metal compounds are filled in the packaging process, which has good color mixing effect and soft luminescence, and is more suitable for indoor application.

Three in one surface sticker refers to that three light-emitting points of red, green and blue are encapsulated and synthesized in the same light-emitting tube. When you look closer, it is a point. When you zoom in, it is a line separated from the three light-emitting points. It has high requirements for materials and processes in the production process. It is mainly used for the production of high-end LED displays with small spacing and high density.

Three in one surface sticker (separate surface sticker) refers to that the three light-emitting points of red, green and blue are packaged separately. After packaging, they are arranged into one pixel point, and then packaged with a mask for protection, which can prevent dust and scratch, and protect the light-emitting chip. Three in one is the separation of table stickers, three-point separate power supply, low power consumption, single lamp maintenance and low cost.

Generally speaking, in order to improve the display effect of indoor screen, three in one surface paste, black light technology, gold wire packaging, etc. are selected.

The LED control part is the core part to determine the display effect. The control circuit has a high-performance single-chip micro control chip. The controller sends the control signal and data to the LED driver chip through the internal control program. After receiving the signal, the LED driver chip generates the corresponding action, so as to realize the independent control of each red, green and blue LED light-emitting chip.

1. Drive system

The function of the LED driving part is to receive color data and drive the LED display screen to display according to the brightness value represented by the data. There are usually three modes: constant current, voltage stabilization and constant voltage constant current.

The output current of the constant current drive circuit is constant, and the output DC voltage changes with the change of load resistance. The whole circuit is not afraid of load short circuit, but it is strictly prohibited to open the load completely. The voltage stabilizing circuit outputs a fixed voltage, and the output current changes with the increase or decrease of the load. The whole circuit is not afraid of open circuit of the load, but it is strictly prohibited to completely short circuit the load. The first constant voltage and then constant current mode is the most ideal driving circuit. It not only detects the LED current, but also controls the LED voltage, which is conducive to improving the LED life and reducing the power consumption. It is generally used in high-grade LED products.

2. Control system

The display effect of stage LED display screen depends on the size and time of current and voltage through it, so the control system mainly controls the power output of LED. At present, the LED power supply designed by PWM (pulse modulation) control mode has a conversion efficiency of 80% 90%, and the output voltage or current is very stable. It is a high reliability power supply.

PWM can control the time ratio of LED on and off. By dividing the time ratio into several levels, the LED displays a corresponding number of gray levels (gray scales). The product of the gray level of the three primary colors is the number of colors that can be reproduced on the display screen in theory, which is generally 256 levels. When the number of colors reaches 16.7M, 24 bit true color information can be displayed.

Generally, the frequency of PWM is greater than 100Hz, otherwise there will be flashing and scanning lines when watching. At present, the gray level of Wittem indoor rental screen is 14 bits and above, the refresh frequency is 1920hz and above, and the highest refresh rate in the LED industry is 6800hz. Under the normal viewfinder and rotation of the camera, the LED screen display is stable without flicker, and the gray scale is too smooth at the highest refresh rate without color mixing.

3. Combination of drive system and control system

As the load of the circuit, the connection between LED and the circuit of driving system and control system is related to the stability of the whole display screen. Generally, there are three modes: series, parallel and hybrid. Series connection is a connection method with low reliability, which is often used in low-end products. In the voltage stabilizing driving circuit, when a LED is short circuited, the voltage distributed to other LEDs will rise, which is easy to cause more damage.

The parallel mode is applicable to products with low power supply voltage. In the constant current drive circuit, when one LED is disconnected, the current distributed to other LEDs will increase, which is easy to damage all LEDs in the circuit.

At present, in order to improve the reliability of products, the mixed connection mode is generally adopted. The number of series and parallel LEDs is evenly distributed, grouped and connected in parallel, and then each group is connected in series. In this way, the voltage distributed on a series of LEDs is the same, the current through each LED is basically the same, and the LED brightness is the same. At the same time, it is best to add LED temperature negative feedback in the constant current output to prevent the LED temperature from being too high.

The whole display screen is spliced by multiple module units. In order to ensure the reliability of power supply and data, hybrid connection must also be adopted to realize the loop backup function. When an abnormal fault occurs in one power supply, other power supplies will automatically conduct intelligent current sharing, so as not to affect the normal use of the system and more effectively improve the fault-free operation time of the system, Reduce failure maintenance time.

4 Special requirements for screen body of stage camera

Although the high refresh rate can ensure that even under the shooting of high-speed camera, the large screen can still respond in time, and the picture conversion and transition are smoother and smoother; However, in the process of use, it will be found that when the camera lens is aimed at the LED display screen, inexplicable water wave like stripes and strange colors occasionally appear, and the water wave will change with the change of shooting angle and the adjustment of camera lens focal length, which will affect the display effect of live broadcast and recording, This is the moire phenomenon brought about by the digitization of TV camera.

If the spatial frequency of the CCD (or CMOS) pixel of the photosensitive element is close to the spatial frequency of the (LED) stripe in the image, a molar stripe will be generated. Since the moire phenomenon is caused by the inherent structure of LED display screen, if one of the conditions for the generation of Moire - the grid structure of LED display screen or the grid structure of camera CCD (CMOS) disappears, the moire interference can be completely eliminated in theory.

Domestic companies superimpose a layer of optical processing screen on the surface of LED display screen, which is composed of specific proportion of special light absorbing material and surface bead lens coating. Through the use of optical screen, the LED screen changes from grid light to continuous surface light. Through the amplification and display of discrete LED pixels, a continuous high-definition image is finally formed on the surface of optical processing screen, While improving the contrast, it retains high definition and eliminates the moire phenomenon.

These Four Factors Need to Be Considered in the Design Scheme of Stage LED Display Screen 1

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Four Factors to Be Considered in the Design Scheme of Stage LED Display Screen
Four Factors to Be Considered in the Design Scheme of Stage LED Display Screen
Before the implementation of the stage rental LED display screen project, it is necessary to make a design scheme, especially when designing the screen body, it is necessary to consider important factors such as the display screen model, display content, installation site environment and cost, and ensure that the production process and technical indicators are suitable for the actual indoor application needs, so as to carry out reasonable design.The sense of visual graininess mainly comes from the fact that the human eye has a certain resolution. When the two points are close to a certain extent, the human eye will not be able to distinguish them. In recent two years, with the improvement of LED display manufacturing technology, the body resolution of Maipu Guangcai small spacing LED display has been continuously improved, and the indoor display design has been improved from the initial selection of the minimum point distance specification scheme to the selection of the appropriate point distance specification scheme.Pixel spacing is the distance between lamp beads, for example, P3 pixel spacing is 3mm; The minimum sight distance is the distance that human eyes can't distinguish pixel particles, but this distance will damage vision if viewed for a long time; The most Jia viewing distance is the comfortable distance to watch the screen, and it is also the clearest distance; The pixel density is the screen definition index. The larger the value, the higher the screen definition; Full HD image and video, screen 16:9 yellow Jin ratio, human vision is the most Hao.According to the analysis in the above table, the rental LED display screens of p1.27, p1.54, P1.6, p1.9 and p2.5 are Maipu Guangcai small spacing LED display screens (point spacing less than 2.5mm). The minimum viewing distance and the most Jia viewing distance are very close to the viewing requirements of large flat panel TV, and the whole screen resolution is up to 4800 2400, clearer pictures can be displayed on the same screen body, but one HD signal needs to be amplified by 3 4 times on a 12m wide screen, and two HD pictures need to be amplified by 2 times; At the same time, high-resolution display requires high-performance image processing equipment, and the overall cost of the system will be very high.P4 and p4.8 cannot display two high-definition pictures at the same time on a 12m wide screen, which can not meet the display requirements of high-definition conference TV pictures. P3 can meet the requirements of displaying two high-definition pictures at the same time. According to the size of the display screen, P3 with high cost performance is finally selected as the display point distance of the main screen and auxiliary screen of the project, and P4 is selected as the display point distance of the monogram screen.One factor that determines the quality of LED is the main materials, such as chip, bracket, glue (epoxy resin), gold wire, etc. the other factor is the packaging process. Pixel packaging technology is related to the color saturation, viewing angle and other display effects of the whole display screen, production cost and quality stability. It is one of the key indicators for selecting LED display screen.The mainstream indoor LED packaging technologies mainly include in-line dip and SMD mode. The in-line module encapsulates the light-emitting tube into a square shape, and then puts the red, green and blue tubes together to make a pixel module, which is directly inserted and welded on the PCB board. The process is relatively simple, the cost is low and the defect rate is high. It is mainly used in outdoor display screens. Surface pasting refers to pasting the encapsulated light-emitting tube on the circuit board, and then processing the integrated circuit welding process into a screen body. It has good heat dissipation and uniform color, and the whole display screen can be maintained in the front, which greatly reduces the maintenance cost and difficulty; At the same time, metal compounds are filled in the packaging process, which has good color mixing effect and soft luminescence, and is more suitable for indoor application.Three in one surface sticker refers to that three light-emitting points of red, green and blue are encapsulated and synthesized in the same light-emitting tube. When you look closer, it is a point. When you zoom in, it is a line separated from the three light-emitting points. It has high requirements for materials and processes in the production process. It is mainly used for the production of high-end LED displays with small spacing and high density.Three in one surface sticker (separate surface sticker) refers to that the three light-emitting points of red, green and blue are packaged separately. After packaging, they are arranged into one pixel point, and then packaged with a mask for protection, which can prevent dust and scratch, and protect the light-emitting chip. Three in one is the separation of table stickers, three-point separate power supply, low power consumption, single lamp maintenance and low cost. Generally speaking, in order to improve the display effect of indoor screen, three in one surface paste, black light technology, gold wire packaging, etc. are selected.The LED control part is the core part to determine the display effect. The control circuit has a high-performance single-chip micro control chip. The controller sends the control signal and data to the LED driver chip through the internal control program. After receiving the signal, the LED driver chip generates the corresponding action, so as to realize the independent control of each red, green and blue LED light-emitting chip.1. The function of the LED driving part of the driving system is to receive color data and drive the LED display screen to display according to the brightness value represented by the data. There are usually three modes: constant current, constant voltage and constant current.The output current of the constant current drive circuit is constant, and the output DC voltage changes with the change of load resistance. The whole circuit is not afraid of load short circuit, but it is strictly prohibited to open the load completely. The voltage stabilizing circuit outputs a fixed voltage, and the output current changes with the increase or decrease of the load. The whole circuit is not afraid of open circuit of the load, but it is strictly prohibited to completely short circuit the load. The first constant voltage and then constant current mode is the most ideal driving circuit. It not only detects the LED current, but also controls the LED voltage, which is conducive to improving the LED life and reducing the power consumption. It is generally used in high-grade LED products.2. The display effect of the stage LED display screen of the control system depends on the size and time of the current and voltage passing through it, so the control system mainly controls the power output of the LED. At present, the LED power supply designed by PWM (pulse modulation) control mode has a conversion efficiency of 80% 90%, and the output voltage or current is very stable. It is a high reliability power supply.PWM can control the time ratio of LED on and off. By dividing the time ratio into several levels, the LED displays a corresponding number of gray levels (gray scales). The product of the gray level of the three primary colors is the number of colors that can be reproduced on the display screen in theory, which is generally 256 levels. When the number of colors reaches 16.7M, 24 bit true color information can be displayed.Generally, the frequency of PWM is greater than 100Hz, otherwise there will be flashing and scanning lines when watching. At present, the gray level of Wittem indoor rental screen is 14 bits and above, the refresh frequency is 1920hz and above, and the most Gao refresh rate in the LED industry is 6800hz. Under the normal viewfinder and rotation of the camera, the LED screen display is stable without flicker, and the gray scale is too smooth at the most Gao refresh rate without color mixing.3. As the load of the circuit, the combined LED of the driving system and the control system is connected with the circuit of the driving system and the control system, which is related to the stability of the whole display screen. Generally, there are three modes: series, parallel and hybrid. Series connection is a connection method with low reliability, which is often used in low-end products. In the voltage stabilizing driving circuit, when a LED is short circuited, the voltage distributed to other LEDs will rise, which is easy to cause more damage.The parallel mode is applicable to products with low power supply voltage. In the constant current drive circuit, when one LED is disconnected, the current distributed to other LEDs will increase, which is easy to damage all LEDs in the circuit.At present, in order to improve the reliability of products, the mixed connection mode is generally adopted. The number of LEDs in series and parallel is evenly distributed, grouped and connected in parallel, and then each group is connected in series. In this way, the voltage distributed on a series of LEDs is the same, the current through each LED is basically the same, and the LED brightness is the same. At the same time, Hao adds LED temperature negative feedback in the constant current output to prevent the LED temperature from being too high.The whole display screen is spliced by multiple module units. In order to ensure the reliability of power supply and data, hybrid connection must also be adopted to realize the loop backup function. When an abnormal fault occurs in one power supply, other power supplies will automatically conduct intelligent current sharing, so as not to affect the normal use of the system and more effectively improve the fault-free operation time of the system, Reduce failure maintenance time.4 Special requirements for screen body of stage cameraAlthough the high refresh rate can ensure that even under the shooting of high-speed camera, the large screen can still respond in time, and the picture conversion and transition are smoother and smoother; However, in the process of use, it will be found that when the camera lens is aimed at the LED display screen, inexplicable water wave like stripes and strange colors occasionally appear, and the water wave will change with the change of shooting angle and the adjustment of camera lens focal length, which will affect the display effect of live broadcast and recording, This is the moire phenomenon brought about by the digitization of TV camera.If the spatial frequency of the CCD (or CMOS) pixel of the photosensitive element is close to the spatial frequency of the (LED) stripe in the image, a molar stripe will be generated. Since the moire phenomenon is caused by the inherent structure of LED display screen, if one of the conditions for the generation of Moire - the grid structure of Maipu brilliant LED display screen or the grid structure of camera CCD (CMOS) disappears, the moire interference can be completely eliminated in theory.Domestic companies superimpose a layer of optical processing screen on the surface of LED display screen, which is composed of specific proportion of special light absorbing material and surface bead lens coating. Through the use of optical screen, the LED screen changes from grid light to continuous surface light. Through the amplification and display of discrete LED pixels, a continuous high-definition image is finally formed on the surface of optical processing screen, While improving the contrast, it retains high definition and eliminates the moire phenomenon.
Apple still Uses Cheaper LCD Screens and Decides to Produce Them by Itself, Endangering the Interests of Many Screen Suppliers
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Apple still Uses Cheaper LCD Screens and Decides to Produce Them by Itself, Endangering the Interests of Many Screen Suppliers
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It is reported that Apple plans to use cheaper LCD screens on most iPhone models next year, while delaying the full conversion to high-tech organic light emitting diode (OLED) screens, which also reflects consumers' price sensitivity.According to the Wall Street Journal, apple is expected to launch an LCD model and two OLED models this fall, and the LCD model is expected to account for most of its iPhone sales. It is expected that Apple will continue to use LCD next year, which is completely inconsistent with the previous report of a complete transition to OLED.Apple announced in March that it was testing its internal microled screen.Apple's decision to insist on using cheaper LCD screens has brought more uncertainty to its screen suppliers; In addition, Apple's decision to produce its own screen endangers the interests of many suppliers.Since apple is not expected to use these products in its OLED screen, the shares of Apple's three LCD suppliers, including sharp, LG display and Japan display, have fallen sharply in the past year. Subsequently, when it was revealed in March that Apple was already testing its microled screen, the shares of many display suppliers, including Samsung, sharp and LG display, fell again. This also damages the interests of general display and Synaptics. After reports showed that Apple would use more LCD screens than expected, the share price of general display company, which provides OLED display materials, began to fall.The Wall Street Journal pointed out that Apple's decision to postpone the implementation of OLED screens does not necessarily bring opportunities for LCD suppliers. For example, LG display has planned to invest in OLED screens.Apple has been facing the problem of supply shortage in the past. If suppliers have to change their production plans, Apple may face supply shortage again. It is reported that Japan display raised $320 million in April to meet the expected demand for its advanced LCD.According to recent reports, Apple has communicated its transformation plan to its suppliers, including plans to reduce parts procurement from suppliers by nearly 20% this year. At the same time, the uncertainty of the continuous expansion of Apple's supply chain will also make the new iPhone more expensive than ever.
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Principle of Touch Screen Capacitance Screen_ What Are the Application Areas of Touch Screen
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Fingerprint identification on mobile phones has become an indispensable part of our daily life.Especially during the epidemic, face recognition is mostly paralyzed due to wearing masks, and fingerprint recognition has become the current optimal solution.Of course, if you use a mobile phone without fingerprint identification such as iPhone x, you have to find a way by yourself...9to5mac also gave a tutorial on using face ID with mask Screen fingerprint identification has become the mainstream, and the technology is also very mature. 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This fingerprint identification scheme can be said to break through the two obstacles of current screen fingerprint identification technology - LCD screen and identification area.If the multi-point fingerprint identification in the LCD screen can achieve mass production, it means that the LCD screen can also use fingerprint identification!Another point is the identification area of off screen fingerprint identification.So far, the identification area of screen fingerprint is basically fixed, almost at the lower position of the screen. People will subconsciously put their fingers at the approximate position when unlocking the mobile phone.But no one can guarantee that every time the finger is pressed on the fingerprint identification area, because the identification area is so large, it is inevitable that there will be deviations...The scheme announced by Tianma this time shows that it can make the whole LCD screen recognize fingerprints!Tony mended his brain, that is, I could identify my fingerprint and unlock my mobile phone by placing my finger anywhere on the screen.If this multi-point fingerprint identification technology can be mass produced, the efficiency of unlocking the screen will be much higher than now. You don't have to find the identification area and poke it on the screen.It can be said that Tianma's operation directly makes the LCD screen ride on the head of OLED in fingerprint identification. Once LCD screens didn't even deserve fingerprint identification. Now they not only have fingerprint identification, but also can identify 5 at a time...As for why the multi-point fingerprint solution in the TFP screen can realize these functions, high integration has played a great role.In short, it is to integrate touch, display and fingerprint identification, replace the previous design of fingerprint identification module and reduce the thickness of the screen, so that the screen fingerprint identification is feasible on the LCD.At the same time, in order to realize fingerprint identification on the whole screen, Tianma covers the whole screen with optical path and sensors.As for how multi-point fingerprint identification can play new tricks, it still depends on the subsequent operations of manufacturers.As for the fate of LCD screen after mass production of this scheme, we still don't know, but before that, LCD screen has never been the first choice for mobile phone manufacturers.After all, the OLED screen is thinner, can emit light by itself, and the color is more bright. The experience is much better than that of LCD, but there are still problems of stroboscopic and screen burning, and the price is relatively expensive.When it comes to the LCD screen, the advantages and disadvantages are reversed...The price of iPhone 11 with LCD screen is lower For most users, OLED screen is their first choice, but there are still a group of people who stick to the LCD screen.In addition to having a larger viewing angle, another reason is that they can't accept the strobe of OLED screen. They think it's really hurting their eyes...Therefore, once the TFP scheme realizes mass production, the defect that the LCD screen has no off screen fingerprint will be supplemented. If the price can be controlled well, the current situation of the screen in the mobile phone market may change a lot.However, before that, the mobile phone market was still dominated by OLED screens, not to mention the suoper AMOLED screens such as Samsung. The evolution of LCD screens has a long way to go...
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What Is the Forming Process of the Flexible Touch Screen
Every day, new products, new experiences, professional membrane switch proofing factory, 12 hour expedited shipmentFrom the hot sale of Samsung Galaxy edge flagship series to the advent of various curved screen bracelets and TVs, it is no doubt that curved screen technology has been widely valued and sought after by consumers and the industry in recent years. In the future, with the continuous development and improvement of fixed curvature curved screen technology, the flexible touch screen that can realize arbitrary bending will become an important development direction. On the 25th, at the 13th International touch screen and display technology development forum, Huang Hanfeng, deputy general manager of touch R & D from Shenzhen oufeiguang technology, made a detailed introduction to the flexible touch screen from the perspective of the industrial chain around the four key elements of flexible display, flexible touch, flexible cover plate and flexible bonding.Flexible displayFor LCD display, the LCD is usually responsible for controlling the display gray, and the three primary color filters control the display color, which requires them to correspond one by one in order to display normally. If the LCD panel is used as a curved screen, the inner circumference and outer circumference will be unequal, and the original one-to-one corresponding liquid crystal and filter will have position deviation, resulting in color distortion. In addition, it will also cause a series of problems such as light leakage, dark screen ghosting and snowflakes. Therefore, for the curved screen, the OLED display technology represented by AMOLED has almost become the best choice.Huang Hanfeng said that at present, Samsung is the undisputed AMOLED overlord in terms of patents, production capacity, yield and technology accumulation. The sixth generation AMOLED panel that began mass production at the end of 2014 can now produce 50000 pieces per month, and the yield can reach 60%. The second is LG, but LG has been focusing on large screen curved TV. At present, with the increasingly obvious trend of small screen AMOLED, LG is also accelerating the layout of small and medium-sized flexible screens. Although its output is not as good as Samsung, its yield can also reach more than 60%. The latest release of Xiaomi note 2 is the flexible AMOLED screen of LG. In addition, Japan's JDI and sharp (already acquired by Hon Hai), Taiwan's Youda, domestic BOE, Rouyu and other screen manufacturers are also accelerating the layout of their own AMOLED technology. It is the general trend for AMOLED to replace LCD.Flexible touchIn terms of touch control, ITO (indium tin oxide) transparent conductive film has become the most important touch layer material for display screens such as non curved LCD and OLED due to its good light transmittance, low thickness, excellent hardness and conductivity, mature manufacturing technology and many other reasons. However, as ITO itself is a brittle material, it is not suitable for making flexible touch layer with large curvature or even free bending, and the cost and cost are high. At present, it accounts for about 30% - 40% of the cost of the upstream material part of the whole touch screen industry, and uses "indium", a rare metal with limited reserves. Therefore, with the advent of the era of curved surface and flexibility, it is likely to be replaced.Huang Hanfeng said that at present, the main substitutes for ITO materials are graphene, carbon nanotubes, nano silver and metal mesh. Graphene and carbon nanotubes are very good substitutes for ITO from the characteristics of the material itself. However, graphene is still in the R & D stage and is still far from mass production. The industrial mass production technology of carbon nanotubes is not perfect, and the conductivity of the thin film products made of carbon nanotubes is not as good as that of ITO. Therefore, from the perspective of technology and marketization, metal grid and nano silver technology will be the protagonists of development in recent years. Metal grid technology has been applied in some PC display markets.The metal mesh technology mentioned here is a conductive metal mesh formed by pressing metal conductive materials such as silver and copper or oxides on thin film substrates such as pet. Its main advantages are low raw material cost and good folding ability. However, due to the problem of Murray interference ripple caused by yield, output and high-speed pixels, it is more suitable for desktop all-in-one computers, laptops, televisions and other products with low resolution and relatively long-distance use.Nano silver technology means that nano silver ink material is coated on pet or glass substrate, and then laser lithography is used to depict the conductive network of nano silver wire. Its main advantages are high yield, small linewidth, good conductivity and folding resistance, while its disadvantage is high cost. Moreover, compared with metal mesh, nano silver material has smaller radius of curvature and small resistance change rate during bending. In addition, due to the linewidth, it is more suitable for high-resolution close-up scenes such as mobile phones, smart watches and bracelets."By comprehensive comparison, I think nano silver has more advantages than metal grid," Huang Hanfeng said.Flexible cover plateIn order to bend at will, in addition to solving the flexible display and flexible touch, the last and most critical part is the flexible cover plate and fitting. However, due to its hard and fragile characteristics, glass cover plate is not the best choice in the field of flexibility.Huang Hanfeng said that compared with glass, pet and PI (polyimide) materials with high surface hardness and high light transmittance are better choices, but at present, pet and PI also have many problems to be solved. On the one hand, they are not resistant to high temperature and have poor light transmittance: pet and PI will have problems of partial melting and property change at low ambient temperature, and they do not have good light transmittance compared with glass.Secondly, it is difficult to achieve a balance between hardness and folding. Huang Hanfeng said that if you want to meet certain hardness requirements, you need to apply the hardened layer, but after coating the hardened layer, after repeated folding, the hardened layer will crack and reduce the hardness. Therefore, how to achieve a balance between the two is the biggest bottleneck at present.Compared with the flexible cover plate that needs further development, the 3D glass cover plate necessary for curved screen mobile phones has a very good development prospect.Some data show that 2018 may become the outbreak year of 3D glass cover plate. It is expected that the mobile phone penetration rate of 3D glass cover plate will exceed 50% around 2020. With the maturity of 3D glass cover plate processing technology and the decline of unit price, the penetration rate will further improve. It is expected that the market scale will reach more than 19 billion yuan in the future.Huang Hanfeng said that the common manufacturing processes of 1R (single radian bending) and 2R cover plates have been basically mature. They basically achieve a bending effect through hot bending technology. The difference is mainly in the coating of hardened layer. However, the yield is a problem to be solved, which is basically only 30%, and there is no room for improvement in the short term. If 4R is to be done in the future, the yield will be lower. Therefore, the yield is one of the urgent problems to be solved in the manufacture of cover plate.Flexible fitAfter the cover plate is selected, it is fitted, that is, the cover plate is integrated with the touch and display layer below to form a complete module. At present, there are two common methods: roller type and vacuum bonding: the roller has high efficiency and needs to roll the pasted object. The efficiency of vacuum type is relatively low, but it does not need to roll the pasted object, so it is not easy to cause damage to the pasted object.Huang Hanfeng said that if the curvature is large, you can only choose vacuum bonding. However, for the possible 4R bonding in the future, due to its special four side bending characteristics, it is difficult to avoid wrinkles and bubbles in places with large radians even if vacuum is adopted. At present, the industry has adopted customized extrusion airbags or plastic parts to alleviate this problem, but it has not been completely solved. Therefore, the industry still has room for progress in multi surface and high curvature fitting technology.Huang Hanfeng frankly said: "from the perspective of the supply chain, it will take several years for the flexible screen to really realize mass production. At the same time, it also needs the upstream and downstream supply chain to jointly overcome the relevant technical problems."For future development, Huang Hanfeng believes that the integration of various modules will be the general trend. He said: "in the incell technology of LCD, ITO touch film and liquid crystal layer are integrated together, which is a good integration. Now the fingerprint module is independent, and it can also be integrated with touch in the future. I think there will be a process of mutual integration and progress between functional modules in the future."
LG Will Mass Produce Mobile Phone Flexible Screen in the Fourth Quarter of This Year
LG Will Mass Produce Mobile Phone Flexible Screen in the Fourth Quarter of This Year
In the early morning of June 20, Beijing time, according to the English version of Korea Times, in order to further consolidate the leading position in the display market, LG display will mass produce a new version of smart phone flexible display from the fourth quarter of this year and provide it to major customers.LG researchers and technicians said that the purpose of producing flexible display is to meet the growing demand for innovative solutions. LG spokesman Frank Lee said that the company is trying to meet the rapidly growing market demand for advanced display screens. Li stressed that the new display screen is foldable and not fragile, and the product will become a major innovation in display technology.LG said it was investing in flexible displays and high-tech panels for mobile devices, namely OLED panels that support high-definition (UHD) displays. "We have completed the development of the first flexible display and will start mass production from the fourth quarter of this year," LG said in a statementThe E2 production line of the company's display manufacturing plant in pozhou, South Korea, will be responsible for the production of flexible displays. LG said that the OLED flexible display will adopt generation 4.5 glass cutting technology, and the monthly production capacity of the production line will be 12000 pieces.Koo Bon moo, chairman of LG, hopes to revive the enterprise by launching leading products. Therefore, as a major shareholder of LG display, LG Electronics will launch its first flexible display smartphone later this year.LG predicts that flexible display may become the latest trend of mobile devices, so the company may also consider selling flexible display to major mobile device manufacturers.It is reported that LG's competitor Samsung display is also developing similar products. At present, Samsung display is testing flexible display products to improve product quality. Due to manufacturing problems, the upcoming Galaxy note 3 should not be configured with a flexible display in the short term.Kim Yang Jae, an analyst at Woori investment securities in Korea, said: "mobile phone manufacturers are increasingly pursuing bright images, beautiful shapes and thin display screens, while flexible display screens cater to this demand. LG display is expected to help them seize a greater market share." Kim said, LG's strategy of switching to flexible display can break the industry conventions and make the company earn stable profits.In fact, flexible display is only one step for LG to invest in different businesses and seize the global market share of OLED. LG is the first company to mass produce OLED display and foldable OLED screen. At the same time, the company is also developing OLED TV supporting high-definition display.Lim Joo soo, manager of LG OLED Technology Strategy Department, said that in order to remain competitive, LG is trying to reduce costs, reduce power consumption and improve image quality. Lim Joo soo said: "LG display is developing high-definition OLED TV screen. In order to improve the brightness, we plan to replace the existing 'bottom light' technology with 'top light' technology. In addition, the company will develop new materials to extend the service life of OLED display."In the next few years, OLED TV will become the mainstream product, and LG plans to expand the TV screen size to 65 inches and 77 inches. LG said that the above two OLED displays will be produced by the M1 test production line of pozhou factory.
LG Will Mass Produce Mobile Phone Flexible Screen in the Fourth Quarter of This Year
LG Will Mass Produce Mobile Phone Flexible Screen in the Fourth Quarter of This Year
In the early morning of June 20, Beijing time, according to the English version of Korea Times, in order to further consolidate the leading position in the display market, LG display will mass produce a new version of smart phone flexible display from the fourth quarter of this year and provide it to major customers.LG researchers and technicians said that the purpose of producing flexible display is to meet the growing demand for innovative solutions. LG spokesman Frank Lee said that the company is trying to meet the rapidly growing market demand for advanced display screens. Li stressed that the new display screen is foldable and not fragile, and the product will become a major innovation in display technology.LG said it was investing in flexible displays and high-tech panels for mobile devices, namely OLED panels that support high-definition (UHD) displays. "We have completed the development of the first flexible display and will start mass production from the fourth quarter of this year," LG said in a statementThe E2 production line of the company's display manufacturing plant in pozhou, South Korea, will be responsible for the production of flexible displays. LG said that the OLED flexible display will adopt generation 4.5 glass cutting technology, and the monthly production capacity of the production line will be 12000 pieces.Koo Bon moo, chairman of LG, hopes to revive the enterprise by launching leading products. Therefore, as a major shareholder of LG display, LG Electronics will launch its first flexible display smartphone later this year.LG predicts that flexible display may become the latest trend of mobile devices, so the company may also consider selling flexible display to major mobile device manufacturers.It is reported that LG's competitor Samsung display is also developing similar products. At present, Samsung display is testing flexible display products to improve product quality. Due to manufacturing problems, the upcoming Galaxy note 3 should not be configured with a flexible display in the short term.Kim Yang Jae, an analyst at Woori investment securities in Korea, said: "mobile phone manufacturers are increasingly pursuing bright images, beautiful shapes and thin display screens, while flexible display screens cater to this demand. LG display is expected to help them seize a greater market share." Kim said, LG's strategy of switching to flexible display can break the industry conventions and make the company earn stable profits.In fact, flexible display is only one step for LG to invest in different businesses and seize the global market share of OLED. LG is the first company to mass produce OLED display and foldable OLED screen. At the same time, the company is also developing OLED TV supporting high-definition display.Lim Joo soo, manager of LG OLED Technology Strategy Department, said that in order to remain competitive, LG is trying to reduce costs, reduce power consumption and improve image quality. Lim Joo soo said: "LG display is developing high-definition OLED TV screen. In order to improve the brightness, we plan to replace the existing 'bottom light' technology with 'top light' technology. In addition, the company will develop new materials to extend the service life of OLED display."In the next few years, OLED TV will become the mainstream product, and LG plans to expand the TV screen size to 65 inches and 77 inches. LG said that the above two OLED displays will be produced by the M1 test production line of pozhou factory.
Design Scheme for Replacing Ch7511b DP to LVDS Screen
Design Scheme for Replacing Ch7511b DP to LVDS Screen
Ch7511b is a DP to LVDS screen conversion chip, and ch7511b is an EDP to LVDS conversion chip. Ch7511b converts the embedded DisplayPort signal to LVDS (low voltage differential signal). Through the advanced decoding / encoding algorithm of ch7511b, the input EDP high-speed serial video data can be seamlessly converted to LVDS. LVDS is a popular high-speed serial link display technology for medium / large LCD displays. This chip is specially designed for the multi-functional integrated PC, industrial computer and notebook computer market.Cs5211 is also an EDP to LVDS bridge chip. Cs5211 has flexible configuration and is suitable for various low-cost display systems. Cs5211 is compatible with EDP 1.2 and supports 1-channel and 2-channel modes. The speed of each channel is 1.62gbps and 2.7Gbps. Cs5211 adopts powerful SerDes technology, which can recover high-speed serial data with low bit error rate.Compared with ch7511b, the advantages of cs5211 in designing DP to LVDS conversion circuit are as follows:1. Cs5211 LVDS transmitter supports single port and dual port modes.2. The maximum resolution supported by cs5211 is WUXGA (1920x1200).3. Cs5211 has 4 configuration pins and can support 16 different combinations of panel resolution and LVDS working mode of an EEPROM image.4. Cs5211 provides a simple tool to edit, generate and update EEPROM images for custom configuration.5. Cs5211 has simple circuit design and fewer peripheral circuit components, which is more conducive to saving BOM cost.6. Cs5211 integrates clock source to save external crystal.7. Cs5211 supports a wide range of power supply (core power is 1.8 1.2V), saving on-board power supply equipment.8. The total power of cs5211 is less than 300MW, which simplifies the design of power supply network and is easy to integrate into the current popular low-cost display system.9. Cs5211 is qfn68 package and ch7511b is also qfn68 package. Overview: cs5211 directly replaces ch7511 without changing the circuit board and pin to pin replacement mode.10. Cs5211 on-chip MCU can update the program online to adjust various parameter values of the screen, improve the universality of the design and product compatibility, and increase the applicable scenario and development and design cost of the scheme product.The detailed characteristic parameters of cs5211 are as follows:Overview:1. 2-channel DisplayPort v1.1 compatible receiverSupports 18 bit single port, 18 Bit dual port, 24 bit single port and 24 bit dual port LVDS outputsSupports open LDI and spwg bit mapping for LVDS applicationsBuilt in oscillator without external crystalEmbedded linear voltage drop regulator (LDO)On Chip MCUSelect the support panel through the GPIO pin controlBoot ROM is loaded automatically after power onUpdate serial boot ROM data via I2C bus or auxiliary channelAutomatic chip power mode control.EMI reduction of EDP and LVDWide core power range from 1.8V to 1.2V.Qfn68 package.HBM 4KV2. DP receiver characteristics:Compliant with embedded display port (EDP) specification 1.2Support 1 or 2 main link channels at 1.62gbps or 2.7Gbps link rate.Enter the color depth of 18 / 24 bits per pixel in RGB format.Support enhanced frame mode.Support VESA and CEA timing standards, resolution up to 1920x1200, 60Hz, 24 bit per pixel mode.Supports dynamic refresh rate switching.Support quick link training and full link training.Support EDP authentication: optional scrambling seed reset and optional frame.Support HPD interrupt.3. LVDS output characteristics:Support 18 bit single port, 18 Bit dual port, 24 bit single port and 24 bit dual port LVDS output interfaces.Supports openldi and spwg bit mapping for LVDS applications.Keep LVDS output when the input video is not ready.Flexible LVDS output pin switching.Programmable swing / common mode voltage.Output conversion rate control to reduce electromagnetic interference.4. Output panel and backlight controlProgrammable LCD panel power sequenceTwo PWM modes are supported, including backlight brightness level control PWM pin and BLUP / bldn pinEditing: JQ
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