thermal management of lcd displays made in china

2023-01-03 12:32:11

Here is a picture inside the TV without the rear cover. The power supply includes the inverter stage for the backlight panel using only two HV transformers. Such design idea sounds very good because all EEFL tubes are connected in parallel avoiding the use of small transformers/inverters stages for each lamp minimizing in this way electronic issues on the backlight stage.

Compared to former CCLF, the new EEFL shows superior performance and applications. This incredible technology combines low power consumption and enhanced luminescence as compared to similar lighting sources. The most attractive feature of EEFL (External Electrode Fluorescent Lamp) is the absence of electrodes in the discharge tube, which is the main factor limiting lamp life. Electrode burn-out is the main cause of fault in CCFL. Because each CCFL lamp need its own ballast the new EEFL technology is simpler in electronics circuitry reducing in this way the rate of failures. EEFL lamps consist of a completely enclosed glass tube with external metal electrodes at both ends. This design minimizes electrode burn-out and results in a longer lamp life. Because the electrodes in former CCFL technology are in direct contact with the rare gasses, CCFL run warmer than the EEFL which are completely cool. On average, EEFL lamps have a lamp life of over 50,000 hours.

I figured out that three main areas on the circuit layout requires additional cooling. The hottest part was the digital class D audio amplifier (STA381BW) because overheats to much (manufacturer datasheet claims approx 3 watts of heat dissipation !!!) so I put a passive aluminum cooler to cool it down. Because the rear plastic cover touched the cooler I cut one of the corners. Using a smaller one was to weak to cool down the device at safe temperatures.

The digital scaler image MT5366 processor and glue logic ICs are located below a metallic RFI shield acting at the same time as a heatsink. Unfortunately the metal shield in use affects the efficiency on thermal conductivity of heat because is to thin leading to hot spots on the components. To correct such design issue the most convenient is to install a passive cooler. To cool down the MT5366 system on chip platform processor an older 486 mother board heatsink (the black one after changes third picture below) do the job well. The use of a thicker heatsink improves the thermal conductivity (spread of heat) avoiding hot spots on the devices.

The last part that requires additional cooling was the HDMI switch inputs selector (SiI9185 device schematic picture above) soldered on the right corner next to the HDMI inputs. Its based on the HDMI 1.3, DDC, HDCP specifications including a CEC (consumer electronics control) single wire bus interface to transmit I/O remote commands through a home network and EDID display identification (plug & play feature stored on serials EEPROMs). Researching datasheets from other versions I figured out that the device in operation consumes approximately 1.5 watts average but such information is not released by manufacturer. The device reach a working temperature of approximately 100 grads Celsius when HDMI inputs are enabled receiving stream data. Watching TV channels (digital DVB or analog cable) the HDMI switch remains cool because is in power down/suspend mode. At glance the HDMI switch overheats only when the inputs are enabled. Without an appropriate heatsink the life endurance of the device is affected because such operating condition can lead to a short circuit on terminals due silicon breakdown !!! . The HDMI switch integrates electrostatic discharge protections on its inputs up to 2kV discarding any possibilities of damages due weak ESD spikes but strong lightning electromagnetic discharges are a big problem without ESD protectors.

In the case of factory cooling all mentioned devices use the "ePad" enhancement, a small metal surface below the IC core case to transfer the silicon heat to PCB board. Despite the idea to reduce manufacturing costs avoiding in this way the use of external heatsinks such cheap PCB cooling solution is not appropriate at all. We verified on all the mentioned devices an excessive heat that unfortunately can lead to operational malfunctions/issues leading to a short durability.

After changes the overall heat is reduced due the improvements on heat conductivity and air convection cooling reducing the average working temperature on overall components avoiding at the same time hot spots on digital ICs (core of the silicon device).

To improve more the cooling on the T-Con LCD panel board we put a SinoGuide TCP400 series thermal pad on the main IC to increase the heat transfer on the metallic shield (this is more thick in diameter and seems to be OK for cooling purposes).

thermal management of lcd displays made in china

BoldVu® displays deliver unparalleled visual performance in outdoor environments. With luminance ratings up to 5000 nits, their high-efficiency LED backlight and obsessively engineered optical stack achieve incredibly bright imagery in the face of intense sunlight – and will do so day-in and day-out for 10 full years. So bring on the sun, BoldVu’s got it managed.

Nothing will destroy a display faster than inadequate thermal management. CoolVu® is BoldVu’s multi-patented thermal management technology that extracts and expels heat from inside the BoldVu®, without exposing display electronics to ambient air or environmental contaminants, like dust, dirt and moisture and without the use of air filters – which means typically no periodic maintenance required. With CoolVu®, BoldVu® displays can operate in environments up to 122°F (50°C) without any degradation in visual performance.

BoldVu® displays are designed to live in a world of turbulence. ToughVu® cover glass shields delicate electronic components from the effects of adverse weather and vandalism. And with its low diffuse reflection, low haze, and anisotropy and bi-refringence qualities, ToughVu® glass ensures that digital imagery shines with brilliance and delivers maximum contrast, color accuracy, color saturation, and viewing angles.

As an added layer of intelligence, BoldVu® displays are equipped with a MEMS sensor which detects and reports on shock and impact events, so in the event of attempted vandalism, you’ll be in the know.

The world is full of spectacular color, and BoldVu® ensures that every one of them is accurately reproduced. The meticulously engineered optical stack achieves ultra-bright whites and super deep blacks so that every color in-between appears as vibrant as you could hope for. A billion colors never looked so good.

At the heart of BoldVu® is a sophisticated logic controller that receives data from electronic components within the display and autonomously optimizes parameters affecting image quality, chassis thermals, and power draw. With built-in intelligence, BoldVu® takes care of itself so you don’t have to.

With an embedded media player and a 13-megapixel camera capable of 4K video at 30fps, BoldVu® makes delivering amazing, interactive campaigns easier than ever. Output gorgeous graphics, measure audience engagement1 via the USB camera, and translate insights into more effective campaigns.

InfiniteTouch® is a next-gen PCAP touch sensor exclusively available on BoldVu® displays. Comprised of multiple layers of glass with index-matched sputter ITO conductors, containing no plastic films, InfiniteTouch® delivers high transmission, low reflection, and true tablet-like responsiveness, making it an incredible platform for delivering engaging interactive experiences.

The Internet of Things (IoT) is changing the way we live, work, and how cities and venues are able to offer digital services to the citizens and visitors they serve. As the IoT continues to grow the need for communications and data processing infrastructure grows with them.

An optional structure affixed atop BoldVu®, the Comms Cap is an additional housing for IoT and connectivity devices designed to extend functionality beyond the edges of the digital screen.

When you place a display out in the world, you never know what to expect. BoldVu® displays self-monitor and report on over 150 operating parameters and settings to the SmartVu® Portal. Via the secure web interface you can see how displays are performing, adjust what they’re doing, and troubleshoot errant behavior, all from anywhere you can access the internet.

BoldVu® LT Semi-Outdoor displays are designed for placement in areas protected from direct sun exposure, like in shopping malls and subway stations where its 850 nit operating luminance is bright but not overbearing.

BoldVu® outdoor displays are intended for deployment in areas out in the open and exposed to the elements. With a daytime operating luminance of 3500 nits BoldVu® is an excellent fit for a wide array of outdoor venues.

BoldVu® XT displays are for outdoor venues with big skies and ultra-bright sunlight like stadiums and raceways. When the sunglasses come out, the 5000 nit daytime luminance of BoldVu® XT still shines bright.

The CoolVu® thermal management system operates without air filters or coolants, requiring zero regular maintenance, while ensuring on-spec performance across temperature extremes (-40°C ~ +50°C / -40° F ~ +122° F).

With full product development, engineering, fabrication, assembly, and configuration under one roof, BoldVu® is a turnkey solution that makes deployment as easy as bolting to the ground, connecting power, and standing back in awe.

BoldVu® is built for as many components to be field replaceable as possible so in the event of part failure or vandalism, displays can be serviced in their installed position and back online with minimal downtime.

2 Intel, the Intel logo, and other Intel names and brands are the sole property of Intel Corporation or its subsidiaries in the US and/or other countries.

4 Power consumption based on full luminance with a white display field, averaged over 10 years of 24/7 use. All figures subject to change without notice.

Nothing will destroy a display faster than inadequate thermal management. CoolVu® is BoldVu’s multi-patented thermal management technology that extracts and expels heat from inside the BoldVu, without exposing display electronics to ambient air or environmental contaminants, like dust, dirt and moisture. With CoolVu®, BoldVu® displays can operate in environments up to 122°F (55°C) without any degradation in visual performance.

An optional structure affixed atop BoldVu®, the Comms Cap is an additional housing for IoT and connectivity devices designed to extend functionality beyond the edges of the digital screen.

2 Intel, the Intel logo, and other Intel names and brands are the sole property of Intel Corporation or its subsidiaries in the US and/or other countries.

4 Power consumption based on full luminance with a white display field, averaged over 10 years of 24/7 use. All figures subject to change without notice.

thermal management of lcd displays made in china

DISPLAY VISIONS (before: ELECTRONIC ASSEMBLY) is THE manufacturer for high quality industrial displays. See here where and how these displays are developed and manufactured.

thermal management of lcd displays made in china

In this article, we"ll focus on color temperature, a fundamental parameter in picture quality adjustments. While color temperature dramatically affects the picture quality of an LCD monitor, more often than not, people simply use the default settings. A good understanding of the meaning of color temperature will enable better adjustments of LCD monitor picture quality.

Note: Below is the translation from the Japanese of the ITmedia article "Altering a color dramatically with a single setting: Examining color temperature on an LCD monitor" published March 30, 2009. Copyright ITmedia Inc. All Rights Reserved.

Most of today"s LCD monitors feature color-temperature adjustment options in their OSD menus. Since color temperature settings affect color reproduction significantly on an LCD monitor, if a user wants to display an image with the appropriate color cast, he or she must choose the correct color temperature.

We"ll start with a brief explanation of the meaning of color temperature. Color temperature refers to the color of light, serving as the standard index for color balance for a range of products, including monitors, cameras, and lighting equipment. Color temperature is specified in units of Kelvin (K) of absolute temperature, not the degrees Celsius (C) used to express the temperature of air and other materials. While Kelvin is less familiar that Celsius, it should present no problems if we keep the following two basic points in mind: the lower the Kelvin value for color temperature, the redder a white object appears; the higher the color temperature, the bluer it appears.

The tables below indicate rough color temperatures for various lighting sources, including sunlight. As you can probably guess, lower color temperatures mean redder light, while higher temperatures mean bluer light. Most photographers shooting pictures with digital SLR cameras might set their white balance to 5000-5500 K. Since daylight has a color temperature of 5000-5500 K, setting the white balance to this figure makes it possible to capture photos with color reproduction close to that perceived by the eye.

A diagram of color temperature. As color temperature decreases, white becomes yellow, then red. As color temperature increases, white gradually turns to blue. Note that this diagram is merely a rough representation of how to think about color temperatures, not a precise indication of color temperatures under specific conditions.

Color is expressed as a temperature due to the relationship between the color of light and temperatures when objects are heated to high temperatures. Here we"ll touch briefly on the technical definition of color temperature. First, assume a subject that can completely absorb heat and light, then radiate this energy back out. This object (an idealized object, not one encountered in reality) is a black body, or perfect radiator. Second, assume that this black body radiates light when heated and that the wavelength and spectrum of this light varies with the temperature of the black body. Third, assume that the temperature of the black body when it radiates a certain color of light is also understood to describe that color. This is how color temperature is defined.

While any object will radiate various light frequencies when heated to high temperature, the temperature at which the light becomes a certain color differs from object to object. For this reason, a black body is an idealized object, used to generate standard values by matching specific colors of radiated light to specific temperatures. While this is a complex topic with detailed explanations grounded in physics and mathematics, we do not need to understand this in depth to adjust the color temperature of an LCD monitor. Anyone with a deeper interest is encouraged to consult reference works.

As mentioned in passing at the start of this session, most current LCD monitors allow users to adjust color temperatures using the OSD menu. As we would expect, reducing the color temperature on an LCD monitor gives the entire screen an increasingly reddish cast, while increasing the color temperature makes the color cast increasingly blue. The menu items for adjusting color temperature vary from product to product. Some ask users to choose from terms like "blue" and "red" or "cool" and "warm"; others ask users to set numerical values like 6500 K or 9300 K.

It helps to be able to specify precise Kelvin values when we adjust the picture quality of an LCD monitor. For example, on most EIZO LCD monitors, users can choose from about 14 levels (in 500-K intervals from 4000 to 10,000 K, plus 9300 K). This is industry-leading precision. Some other LCD monitors allow users to designate color temperature by Kelvin value. Most offer significantly fewer options in the OSD menu: 5000, 6500, and 9300 K, for example.

On most EIZO LCD monitors, users can adjust color temperature precisely from the OSD menu in 500-K intervals (photo at left). Using the bundled ScreenManager Pro software for LCD monitors to configure various display settings from the PC, users can easily adjust color temperatures simply by moving the position of a slider at the top of the screen (photo at right).

A color temperature of 6500 K is standard for ordinary PC use and for the sRGB standard. Most LCD monitors offer a setting of 6500 K among their color temperature options. If a monitor offers an sRGB mode, setting it to this mode should present no problems. In most cases, even products whose color-temperature settings use terms like "blue" and "red" will be adjusted to close to 6500 K for standard mode, although accuracy may be lacking. The LCD monitors on some laptop PCs are set to higher color temperatures.

In the field of video imaging—television, for example—the current standard under Japanese broadcasting standards (NTSC-J) is 9300 K. This is significantly above the 6500 K standard for PC environments. Television pictures actually have a pronounced blue cast. However, most people appear to be accustomed to television and often perceive PC screens as having a reddish cast. Some products offer a picture mode with a color temperature around 9300 K as a "movie" or similar mode. When viewing the picture from a television tuner in a PC environment, one can generally choose a color temperature of 9300 K for color reproduction similar to a home television display.

On the other hand, the U.S. broadcasting standard (NTSC) calls for a color temperature standard of 6500 K. The international standard for digital high-definition television (ITU-R BT.709) also specifies a color temperature of 6500 K. When watching video on a PC, users should set the LCD monitor"s color temperature between 6500 K and 9300 K, checking for differences in color reproduction.

As a rule of thumb, most Japanese film titles assume a 9300 K environment, while non-Japanese films assume a 6500 K environment. This means one is highly likely to achieve color reproduction close to that intended by filmmakers by setting the color temperature of an LCD monitor to 9300 K when viewing a Japanese film and 6500 K when viewing a non-Japanese film. (Naturally, this doesn"t apply universally.) When using a model with a wide range of choices in Kelvin values—an Eizo Nanao LCD monitor, for example—users can adjust the color temperature to whatever looks best.

A color temperature of 5000 K (D50) is standard in the field of desktop publishing (DTP) for printing or publishing. This is the color temperature recommended for lighting by the Japanese Society of Printing Science and Technology when evaluating colors for print applications. While this standard might give a distinct reddish cast to whites in pictures prepared to the standards of television video or similar images, it is intended to reproduce the look printed colors have when viewed under conditions close to direct sunlight.

Sample display of white under the color temperatures 5000, 6500, and 9300 K (from left). Since the photo was shot with the color temperature of the digital camera set to 6500 K, white in the 6500 K image in the center appears pure white. It appears red in the 5000 K image and blue in the 9300 K image. Naturally, when changing the color temperature setting for the camera, the look of whites in those images will be shifted accordingly: the image with a color temperature lower than the set value will appear reddish and the one with a higher color temperature will look bluish.

Sample color bars displayed at color temperatures 5000, 6500, and 9300 K (from left). The photo was shot under the same conditions as the photo above. As color temperatures change, the apparent color of the white, or the overall color balance, is affected. Colors at lower color temperatures tend to appear warm; at higher color temperatures, they tend to appear cool.

The preceding page explained the basics needed to set the correct color temperature based on the intended application. However, for applications like retouching digital photographs or color adjustments for printing or video editing, where users are professionals or high-end amateurs for whom color reproduction significantly affects the final quality of the work, managing LCD color temperatures with greater accuracy is critical. If colors differ between the output of photo retouching and the color reproduction in printing, or colors appear unnatural when a video is viewed on another computer, it could not only impair the work itself, but also significantly reduce the efficiency of image processing.

Addressing these demands adequately requires an LCD monitor that supports color management based on hardware calibration. A hardware calibration system uses a color sensor to measure colors on screen and controls the look-up table (LUT) in the LCD monitor directly. This makes it possible to correct for differences in color temperature attributable to differences between individual LCD monitor units or to an aging display and to generate accurate colors, an important feature when handling color.

Here we"ll use an EIZO LCD monitor with a good reputation for enabling high-precision color management to briefly explain the knowledge and specialized tools required to work with color temperatures at a deeper level. We also recommend reading the articles below for more information on hardware calibration, color gamut, and look-up tables.

EIZO offers the ColorEdge series of color management-capable LCD monitors. All models in the ColorEdge series support hardware calibration, allowing users to manage in detail all aspects of color reproduction, including screen color temperature and color gamut.

Designed for advanced color management, the ColorNavigator software is bundled with all models in the ColorEdge series. ColorNavigator offers a wide range of functions, including a function for matching the color temperature of the LCD monitor with the white of a particular paper. Using a color sensor (sold separately), users can measure a white point on the paper and set this to white when performing a hardware calibration of the LCD monitor. This makes it possible to precisely match the on-screen white and the paper white, ensuring that colors on screen are very close to those on the printed paper.

ColorNavigator also offers an advanced function for emulating any color gamut. This lets users reproduce on screen, with high precision, the Adobe RGB, sRGB, or NTSC color gamut, using a wide color-gamut panel. ColorNavigator can also be set to emulate color gamuts by reading existing ICC profiles, rather than relying on preset software gamuts. For example, for commercial applications, emulating the client"s LCD monitors using their ICC profiles lets users streamline the color-proofing workflow by reproducing the color reproduction of the client"s monitors on a ColorEdge monitor.

ColorNavigator also features functions that encourage users to perform periodic hardware calibration of their LCD monitors and to maintain accurate color reproduction through precise manual adjustments. Since screen brightness and color reproduction change as a monitor is used over many years, color temperatures will also change. In applications for which accurate color reproduction is paramount, merely selecting preset color-temperature settings is not enough. It"s a good idea to perform hardware calibration once a month or so.

ColorNavigator software is designed for use with the ColorEdge series. Eizo EasyPIX, another tool, is available for the general-purpose FlexScan SX and FlexScan S series to make it easier to match colors.

Based on a special-purpose EX1 sensor and special-purpose software, EasyPIX lets users easily match on-screen and printed colors. This is done by visually comparing the white displayed on screen with the white of the paper and manually adjusting on-screen tint and brightness using the special software until both tints look the same. The special sensor is used to measure on-screen color and to bring it more in line with the white of the paper. EasyPIX also offers functions for adjusting color casts closer to those of natural light or flashbulbs (color temperature: 5500 K) and to standard color casts for Web content and general PC applications (color temperature: 6500 K).

In addition to adjusting LCD monitors with special tools like ColorNavigator or EasyPIX, one should closely examine worksite (environmental) lighting and LCD hoods.

Most worksites use fluorescent lighting. Some fluorescent lighting is suitable for working with color; others are not. The majority of fluorescent lights sold to the general public are not suitable for color work. Ordinary fluorescent lights have a highly biased light spectra, and color divergence is readily apparent if we compare the LCD monitor screen to paper. Accurately printed colors, for example, may appear greenish under fluorescent light.

Fluorescent lights suitable for working with color are known as high color-rendering fluorescent lamps or fluorescent lights for color evaluation. These lamps feature light spectra similar to the sun and generate very little color divergence between the LCD monitor screen, printed paper, and human color recognition. Color rendering describes the color an object appears to have under a certain light. Color-rendering performance is expressed in terms of the average color-rendering index (Ra). An Ra value of 100 means the lighting is identical to natural light. The closer the value to Ra, the higher the color-rendering performance. The International Commission on Illumination (CIE) recommends fluorescent lighting with an Ra of 90 or above at locations where art is viewed or colors evaluated.

Most high color-rendering fluorescent lamps are tubes, making them difficult to use in most homes without modification. In these cases, we recommend three-wavelength fluorescent lamps, which offer relatively high color-rendering performance for fluorescent lamps and are readily available to the general public. To determine if a fluorescent lamp is a three-wavelength model, simply look at the lamp"s specifications. With respect to the color temperature of the fluorescent lamp itself for evaluating printed materials, a daylight lamp (4600-5400 K) is ideal.

An LCD hood is attached to the top and sides of an LCD monitor to reduce the effects of environmental lighting on the screen display and to make it possible to view the true screen colors while working.

An LCD hood specially designed as an option for an LCD monitor is ideal, but if no such option is available, the user can make an LCD hood by cutting a piece of cardboard, plastic sheet, or polystyrene board to the size of the display and painting the entire surface facing the LCD monitor screen matte black to minimize light reflections. In the end, the hood simply needs to block environmental light from reaching the screen of the LCD monitor and not reflect display light back onto the screen. Make sure the hood doesn"t also block the heat release vents on the LCD monitor; heat buildup inside the monitor can damage the unit.

We"ve examined some basic aspects of color temperature and of using and adjusting color temperatures on an LCD monitor. The color cast of an LCD monitor varies dramatically with color temperature settings—the difference is hard to miss. If you"ve used nothing but your monitor"s default settings up to this point, we encourage you to explore the OSD menu and see how colors change at different color temperature settings. While 6500 K, sRGB mode, or "standard" mode is recommended for general PC use, you might find that you prefer a different color temperature for watching films, playing computer games, or other uses.

thermal management of lcd displays made in china

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thermal management of lcd displays made in china

DISPLAY VISIONS (before: ELECTRONIC ASSEMBLY) is THE manufacturer for high quality industrial displays. See here where and how these displays are developed and manufactured.

thermal management of lcd displays made in china

In addition to adjusting LCD monitors with special tools like ColorNavigator or EasyPIX, one should closely examine worksite (environmental) lighting and LCD hoods.

thermal management of lcd displays made in china

The flat-panel display market is starting to recover after a period of oversupply and lackluster growth, fueled by new technologies as well as more people working from home.

The flat-panel display market is complex. Several different technologies are at play, such as liquid-crystal displays (LCDs) for TV screens and other products, as well as organic light-emitting diodes (OLEDs) for smartphones. Cars, industrial equipment, PCs and tablets all incorporate flat-panel displays in one form or another. And for many products, the display is a big selling point for consumers.

For the flat panel market as a whole, 2019 was a tough year. Oversupply caused prices to drop, which in turn sparked some major changes in the landscape. Two South Korean suppliers — LG Display and Samsung — are retreating from the low-margin LCD business to focus on higher-end display technologies. Meanwhile, China-based suppliers have been building up a massive amount of fab capacity, with plans to dominate several sub-segments in the arena.

2020 was supposed to be another gloomy year. Then, the COVID-19 pandemic struck. A large segment of the population was (and is still) forced to work at home due to the pandemic, disrupting the world’s economies. If there is a silver lining, the work-at-home economy is fueling demand for several products, thereby jumpstarting the display market.

Capital spending for displays also appears to be a bright spot, which is welcome news for flat-panel display equipment suppliers. “(There is a) continuing investment in large panels for TVs and a recovery in investment for OLED for mobile applications,” said Toshiki Kawai, president and CEO of TEL, in a recent presentation. In terms of capital spending, the industry “is expecting approximately 15% year-over-year growth in CY2000,” Kawai said.

Apple and other smartphone OEMs continue to migrate from LCDs toward brighter OLED displays. Samsung is the leader in OLED fab production, but China is making a major push here.

The smartphone display market is dynamic. Smartphone displays based on OLED technology continues to take share away from LCDs, and the new 5G smartphones will accelerate that trend. Plus, foldable phones and tablets using OLED displays are finally shipping after several false starts.

An LCD is a mature and inexpensive technology with several parts. A backlight module is on the bottom of an LCD screen, followed by a thin-film transistor (TFT) array, liquid crystals, a color filter (red/green/blue), and a polarizer.

LCDs consist of a multitude of pixels. A pixel consists of three sub-pixels—red/green/blue (RGB). “A change in voltage applied to the liquid crystals changes the transmittance of the panel, including the two polarizing plates, and thus changes the quantity of light that passes from the backlight to the front surface of the display. This principle allows the TFT LCD to produce full-color images,” according to Japan Display.

Meanwhile, active-matrix OLEDs (AMOLEDs) use a series of thin, light-emitting films, which enable brighter displays than LCDs. OLEDs are also flexible, but they are more expensive than LCDs.

LCDs and OLEDs are manufactured in fabs using an assortment of equipment. Korea is still the OLED leader in terms of fab capacity with a 67% share, according to Omdia. But China is making a big push here, as the nation’s share of OLED fab capacity has jumped from 1% in 2014 to 31% in 2020, according to the firm.

By 2022, China is projected to have 21 small- to mid-sized display fabs, including LCD and OLED. Some 14 fabs are in production in China with 7 in the works, according to the firm. China also is building new fabs for large-screen LCDs for TVs.

“In case of the OLEDs, China is aggressively investing in new capacity. But long-term, we also see that Korean OLED capacity will dominate,” Omdia’s Hsieh said.

On the product front, meanwhile, 70% of all smartphones use traditional LCD screens today, while 30% incorporate OLEDs, according to Omdia. By 2024, OLEDs will represent about 43% of the smartphone display market, they added.

5G, a next-generation wireless standard that is faster than today’s 4G, also will propel OLEDs. “AMOLED displays will grow, along with the 5G mobile phone market, due to their superior power consumption characteristics, which is lower than that of LCD displays,” said T.T. Yang, deputy division director of corporate marketing at UMC. “In addition, TDDI is the display driver IC with the touch controller function integrated on the same silicon chip, which has become very popular within the smartphone market over the past two years. It has started to expand into other applications for growth as TDDI has recently faced strong competition from AMOLED displays for smartphones. The new applications for TDDI include tablets, automotive display and others.”

Meanwhile, Samsung, the leading supplier of OLEDs, continues to improve the technology. Samsung developed a new OLED adaptive frequency technology, which reduces the power consumption of a display. “High-definition video streaming and gaming are expanding their capabilities in line with 5G commercialization, creating a widespread need for display panel technologies that can enable greater power savings,” said Ho-Jung Lee, vice president of mobile display products at Samsung Display.

Meanwhile, Apple’s iPhone 11 line consists of three models, including two OLED-based systems and one LCD product. For the upcoming iPhone 12, Apple will incorporate OLEDs in all models. The iPhone 12 also represents Apple’s entry into 5G.

Here’s what to expect for two iPhone 12 models: “The iPhone 12 Max is expected to be 5G using sub-6GHz technology and will feature a 6.1-inch flexible OLED sourced from BOE and LG Display with an add-on touch sensor and a rumored resolution of 2540 x 1174 or 460 PPI,” according to DSCC. “(The OLED for the) iPhone 12 Pro Max is expected to be exclusively supplied by Samsung Display and will have a 6.67-inch 2785 x 1293 flexible OLED panel.”

Other OLED segments also are growing. After years of hype, smartphones/tablets using foldable OLED displays are finally shipping. Samsung is shipping the Galaxy Fold, which features a 7.3-inch AMOLED display that can be folded into a compact 4.6-inch cover display.

Foldable systems, however, face some challenges, such as power consumption, component readiness, mechanical issues and cost. Samsung’s Galaxy Fold sells for a retail price of $1,980, according to Omdia.

In terms of total area, LCDs for TVs represents the biggest market in the flat-panel display business. LCD TVs are commonplace today, but so-called advanced TVs are making inroads.

Bob O’Brien, president of DSCC, defines an advanced TV as a system with an advanced display. In the advanced TV arena, consumers have a dizzying array of technology choices — 8K, dual-cell, microLED, miniLED, OLED TVs and quantum dot TVs.

The advanced TVs incorporate dazzling displays, but they are expensive and the market is still tiny. “Turning to the long-term forecast, we expect that advanced TV shipments will grow from less than 10 million in 2019 to nearly 35 million in 2025, a 24% CAGR for that time period,” O’Brien said.

LCD TVs still dominate the consumer market, simply because they provide enough features at low price points. But LCD TV prices continue to tumble, forcing LCD vendors to develop and sell products at razor thin margins.

LCD TV technology is identical to LCDs for smartphones, but it’s on a much bigger scale. All LCDs are built in giant fabs using various equipment. The LCD manufacturing process takes place on an entire sheet of glass or substrate. Some glass sizes are the size of a garage door.

Today’s mainstream LCD TV fabs are based on Gen 8.5 and 10.5 technology. The term “Gen,” or generation, denotes the glass size. Gen 8.5 fabs produce panels at sizes of 2,200 x 2,500mm, while Gen 10.5 are 2,940 x 3,370mm.

The idea behind LCD manufacturing is to reduce the cost of the panel. To drive down the cost, a giant panel is fabricated in the fab and then cut into smaller displays. For example, Gen 10.5 fabs, the world’s largest plants, are ideal for making 43-, 65- and 75-inch LCD TV panels.

Nonetheless, in 2017, China took the lead over South Korea in terms of overall LCD fab capacity. In 2020, China will have 57% of the world’s TFT LCD fab capacity, according to Omdia. Taiwan is in second place (25%), followed by Korea (13%) and Japan (6%), according to the firm.

China continues to build LCD fabs. By 2022, China is projected to have 22 large-screen LCD display fabs. Some 15 fabs are in production with 6 in the works. That also includes China-based LCD fabs from both LG and Samsung, which are on the block.

For example, LG Display is developing and selling large-screen OLED TVs with mixed results. OLED TVs have bright displays, but they are still expensive. OLED technology is similar for both TVs and smartphones.

OLED TVs continue to improve. At Display Week, LG Display presented a paper that outlined a new OLED display with a motion blur reduction technology. A key to the technology is a new gate driver IC. “The MPRT (moving picture response time) value of the 65‐inch ultrahigh‐definition OLED panels decreased by 3.4ms by using an integrated gate driver circuit,” said Hong Jae Shin, a researcher at LG.

OLEDs involve a complex manufacturing process, especially the development of the RGB sub-pixels. For this, a fine metal mask process is used to produce the sub-pixels.

Instead of the traditional methods, a company called JOLED is developing OLEDs using an inkjet printer. Using this technology, JOLED has developed 4K OLED monitors. “We have developed our own printing technology as a manufacturing method that can be developed in various sizes while maintaining high definition of over 200 ppi,” said Kazuhiro Noda, an executive officer at JOLED, in a paper at Display Week.

In another advanced TV category, Samsung and TCL are pushing quantum dot TVs. Quantum dots are inorganic semiconductor nanocrystals. When inserted into an LCD TV, quantum dots can boost the color gamut in the display.

8K TVs are also in the mix. Based on LCD technology, an 8K TV consists of a 7,680 x 4,320 screen, which equates to 33 million pixels, according to Samsung.

In displays, the big buzz revolves around two technologies — microLEDs and miniLEDs. Both are smaller versions of an older technology called light-emitting diodes (LEDs).

Traditional LEDs, which convert electrical energy into light, are used for backlights in LCD displays, billboards, consumer electronic items and lighting. LEDs come in different configurations, such as monochrome and multi-color. An RGB LED, one popular type, consists of the primary colors in the gambit. These can create a number of different colors.

The size of an LED is 200μm and above. In comparison, a miniLED ranges in size from 50μm to 200μm. Like LEDs, miniLEDs are targeted for backlights in displays.

Measuring smaller than 50μm, microLEDs are self-emissive and don’t require a backlight. In theory, a display using microLEDs provides more color and higher brightness with lower power than competitive displays.

“MiniLEDs, which are larger than microLEDs, are now being incorporated in consumer devices such as TVs,” said Subodh Kulkarni, president and CEO of CyberOptics. “But microLED is an even more exciting area of innovation that is poised for growth. The disruptive technology enables products that are brighter, thinner, lighter and more dynamic than those currently on the market, with lower power consumption than LCDs or OLEDs. Tiny microLEDs can also be placed on flexible substrates. These advantages will continue to propel this technology forward.”

Apple, Facebook and Samsung are just a few of the companies developing microLEDs. Companies are working on microLEDs for a range of applications, such as displays for AR/VR, TVs and watches.

But microLEDs are still several years away from being a mainstream technology. There are too many technical hurdles. “A major challenge is the small size and complex structure of microLED chips. For microLEDs, these dimensions are one to two orders of magnitude smaller than traditional LEDs,” said Steve Hiebert, senior director of marketing at KLA. “From a process control perspective, the transition to microLED displays creates a number of major challenges that must be overcome. In order to have economic viability, there are complicated tradeoffs between microLED size, wafer-level yield, microLED redundancy and microLED repair.”

Take an 8K TV, for example. For this, a company must make millions of microLEDs in the fab and then transfer them onto the backplane at high speeds and with good yields.

“An 8K display requires close to 100 million individual microLEDs. To ensur

thermal management of lcd displays made in china

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