lcd display freezing temperature factory

Liquid crystal displays (LCD) have become an essential component to the industry of display technology. Involved in a variety of contexts beyond the indoors like LCD TVs and home/office automation devices, the LCD has expanded its usage to many environments, such as cars and digital signage, and, thus, many temperature variations as well.

As with any substance that requires a specific molecular characteristic or behavior, LCDs have an operating temperature range in which the device, if within, can continue to function properly and well. In addition to that, there is also an ideal storage temperature range to preserve the device until used.

This operating temperature range affects the electronic portion within the device, seen as falling outside the range can cause LCD technology to overheat in hot temperatures or slow down in the cold. As for the liquid crystal layer, it can deteriorate if put in high heat, rendering it and the display itself defective.

In order for the LCD panel to avoid defects, a standard commercial LCD’s operation range and storage range should be kept in mind. Without adaptive features, a typical LCD TV has an operating range from its cold limit of 0°C (32°F) to its heat limit of 50°C (122°F) (other LCD devices’ ranges may vary a bit from these numbers).

The storage range is a bit wider, from -20°C (-4°F) to 60°C (140°F). Though these ranges are quite reasonable for many indoor and even outdoor areas, there are also quite a few regions where temperatures can drop below 0°C or rise above 32°C, and in these conditions, LCDs must be adapted to ensure functionality.

Heat, can greatly affect the electronics and liquid crystals under an LCD screen. In consideration of heat, both external heat and internally generated heat must be taken into consideration.

Seen as the liquid crystals are manipulated in a device by altering their orientations and alignments, heat can disrupt this by randomizing what is meant to be controlled. If this happens, the LCD electronics cannot command a certain formation of the liquid crystal layer under a pixel, and the LED backlighting will not pass through as expected, which can often lead to dark spots, if not an entirely dark image. This inevitably disrupts the display’s readability.

Depending on the upper limit of the operation temperature range, LCD device can be permanently damaged by extreme heat. With long exposure to extreme heat, besides the destruction of the liquid crystals, battery life can shorten, hardware can crack or even melt, response time may slow to prevent even more heat generation from the device.

The LED backlight and the internal circuitry, typically TFT-based in the common TFT LCDs, are components that can generate heat that damages the device and its display. To address this concern with overheating, many devices use cooling fans paired with vents.

Some devices that are used in extremely high ambient temperatures may even require air conditioning. With air vents to carry the heat out, the device can expel it into the surroundings.

But this leads to another problem: how can moisture be prevented from entering through the vent? If moisture enters the device and high heat is present, condensation can occur, fogging the display from inside, and in some cases, short-circuiting may cause the device to turn off. In order to circumvent this issue, the shapes of the air vents are specific in a way that allows only for air movement, not forms of moisture.

In the opposite direction is extreme cold. What typically occurs in the cold is “ghosting” (the burning of an image in the screen through discoloration) and the gradual slowing and lagging of response times. Like heat-affected LCD modules, the extreme temperature can affect the liquid crystals. This layer is a medium between the liquid and solid state, so it is still susceptible to freezing.

An LCD device can be left in freezing temperatures because it will likely not be permanently damaged like in the heat, but it is important to understand the device’s limits and how to take precautions when storing the device. The standard and most common lower-bound storage range limit is -20°C, below freezing, but if possible, it would be best to keep it above that limit, or else there is still a risk of permanent damage.

If the device is not adapted for the cold, it would be good to keep it bundled up, trapping the heat within layers. However, this is only a temporary solution. Adapted, rugged devices have advantages such as screen enclosure insulation for heat level preservation and, in more extreme cases, heaters to generate extra heat to raise the internal temperature to a level above the minimum.

When selecting the appropriate module, it is necessary to understand the device’s expected primary application. The application will decide factors such as display type, environmental conditions, whether or not power consumption is a factor, and the balance between performance and cost. These factors can have an effect on the operation and storage temperature ranges for the device.

Display types have a lot of variation. Choices like alphanumeric or graphic LCD, human-machine interactive LCD modules and touchscreen panels capabilities, the width of the viewing angle, level of contrast ratios, types of backlighting, and liquid crystal alignment methods are often considered. For example, the twisted nematic LCD provides for the fastest response time at the lowest cost, but cannot offer the highest contrast ratio or widest viewing angle.

Environment-based factors must consider things besides the obvious temperature like UV exposure and humidity/moisture, as they all are necessary in finding the perfect fit extreme temperature LCD module.

Besides the LCD modules, recent new products have opened doors in wide temperature range displays, such as OLED displays. OLED displays offer better displays in regard to contrast, brightness, response times, viewing angles, and even power consumption in comparison to traditional LCD displays.

These benefits, in addition to its ability to achieve a wide temperature range, provide more options for consumers in search of high quality displays for extreme climates.

The use of liquid crystal displays (LCDs) in user interface assemblies is widespread across nearly all industries, locations, and operating environments. Over the last 20 years, the cost of LCD displays has significantly dropped, allowing for this technology to be incorporated into many of the everyday devices we rely on.

The odds are high you are reading this blog post on a laptop or tablet, and it’s likely the actual screen uses LCD technology to render the image onto a low-profile pane of glass. Reach into your pocket. Yes, that smartphone likely uses LCD technology for the screen. As you enter your car, does your dashboard come alive with a complex user interface? What about the menu at your favorite local drive-thru restaurant? These are some everyday examples of the widespread use of LCD technology.

But did you know that the U.S. military is using LCD displays to improve the ability of our warfighters to interact with their equipment? In hospitals around the world, lifesaving medical devices are monitored and controlled by an LCD touchscreen interface. Maritime GPS and navigation systems provide real-time location, heading, and speed information to captains while on the high seas. It’s clear that people’s lives depend on these devices operating in a range of environments.

As the use of LCDs continues to expand, and larger screen sizes become even less expensive, one inherent flaw of LCDs remains: LCD pixels behave poorly at low temperatures. For some applications, LCD displays will not operate whatsoever at low temperatures. This is important because for mil-aero applications, outdoor consumer products, automobiles, or anywhere the temperature is below freezing, the LCD crystal’s performance will begin to deteriorate. If the LCD display exhibits poor color viewing, sluggish resolution, or even worse, permanently damaged pixels, this will limit the ability to use LCD technologies in frigid environments. To address this, there are several design measures that can be explored to minimize the impact of low temperatures on LCDs.

Most LCD displays utilize pixels known as TFT (Thin-Film-Transistor) Color Liquid Crystals, which are the backbone to the billions of LCD screens in use today. Since the individual pixels utilize a fluid-like crystal material as the ambient temperature is reduced, this fluid will become more viscous compromising performance. For many LCD displays, temperatures below 0°C represent the point where performance degrades.

Have you tried to use your smartphone while skiing or ice fishing? What about those of you living in the northern latitudes - have you accidently left your phone in your car overnight where the temperatures drop well below freezing? You may have noticed a sluggish screen response, poor contrast with certain colors, or even worse permanent damage to your screen. While this is normal, it’s certainly a nuisance. As a design engineer, the goal is to select an LCD technology that offers the best performance at the desired temperature range. If your LCD display is required to operate at temperatures below freezing, review the manufacturer’s data sheets for both the operating and storage temperature ranges. Listed below are two different off-the-shelf LCD displays, each with different temperature ratings. It should be noted that there are limited options for off-the-shelf displays with resilience to extreme low temperatures.

For many military applications, in order to comply with the various mil standards a product must be rated for -30°C operational temperature and -51°C storage temperature. The question remains: how can you operate an LCD display at -30°C if the product is only rated for -20°C operating temperature? The answer is to use a heat source to raise the display temperature to an acceptable range. If there is an adjacent motor or another device that generates heat, this alone may be enough to warm the display. If not, a dedicated low-profile heater is an excellent option to consider.

Made of an etched layer of steel and enveloped in an electrically insulating material, a flat flexible polyimide heater is an excellent option where space and power are limited. These devices behave as resistive heaters and can operate off a wide range of voltages all the way up to 120V. These heaters can also function with both AC and DC power sources. Their heat output is typically characterized by watts per unit area and must be sized to the product specifications. These heaters can also be affixed with a pressure sensitive adhesive on the rear, allowing them to be “glued” to any surface. The flying leads off the heater can be further customized to support any type of custom interconnect. A full-service manufacturing partner like Epec can help develop a custom solution for any LCD application that requires a custom low-profile heater.

With no thermal mass to dissipate the heat, polyimide heaters can reach temperatures in excess of 100°C in less than a few minutes of operation. Incorporating a heater by itself is not enough to manage the low temperature effects on an LCD display. What if the heater is improperly sized and damages the LCD display? What happens if the heater remains on too long and damages other components in your system? Just like the thermostat in your home, it’s important to incorporate a real-temp temperature sensing feedback loop to control the on/off function of the heater.

The first step is to select temperature sensors that can be affixed to the display while being small enough to fit within a restricted envelope. Thermistors, thermocouples, or RTDs are all options to consider since they represent relatively low-cost and high-reliability ways to measure the display’s surface temperature. These types of sensors also provide an electrical output that can be calibrated for the desired temperature range.

The next step is to determine the number of temperature sensors and their approximate location on the display. It’s recommended that a minimum of two temperature sensors be used to control the heater. By using multiple sensors, this provides the circuit redundancy and allows for a weighted average of the temperature measurement to mitigate non-uniform heating. Depending on the temperature sensors location, and the thermal mass of the materials involved, the control loop can be optimized to properly control the on/off function of the heater.

Another important consideration when selecting a temperature sensor is how to mount the individual sensors onto the display. Most LCD displays are designed with a sheet metal backer that serves as an ideal surface to mount the temperature sensors. There are several types of thermally conductive epoxies that provide a robust and cost-effective way to affix the delicate items onto the display. Since there are several types of epoxies to choose from, it’s important to use a compound with the appropriate working life and cure time.

For example, if you are kitting 20 LCD displays and the working life of the thermal epoxy is 8 minutes, you may find yourself struggling to complete the project before the epoxy begins to harden.

Before building any type of prototype LCD heater assembly, it’s important to carefully study the heat transfer of the system. Heat will be generated by the flexible polyimide heater and then will transfer to the LCD display and other parts of the system. Although heat will radiate, convect, and be conducted away from the heater, the primary type of heat transfer will be through conduction. This is important because if your heater is touching a large heat sink (ex. aluminum chassis), this will impact the ability of the heater to warm your LCD display as heat will be drawn toward the heat sink.

Insulating materials, air gaps, or other means can be incorporated in the design to manage the way heat travels throughout your system on the way toward an eventual “steady state” condition. During development, prototypes can be built with numerous temperature sensors to map the heat transfer, allowing for the optimal placement of temperature sensors, an adequately sized heater, and a properly controlled feedback loop.

Before freezing the design (no pun intended) on any project that requires an LCD display to operate at low temperatures, it’s critical to perform low temperature first. This type of testing usually involves a thermal chamber, a way to operate the system, and a means to measure the temperature vs time. Most thermal chambers provide an access port or other means to snake wires into the chamber without compromising performance. This way, power can be supplied to the heater and display, while data can be captured from the temperature sensors.

The first objective of the low-temperature testing is to determine the actual effects of cold exposure on the LCD display itself. Does the LCD display function at cold? Are certain colors more impacted by the cold than others? How sluggish is the screen? Does the LCD display performance improve once the system is returned to ambient conditions? These are all significant and appropriate questions and nearly impossible to answer without actual testing.

As LCD displays continue to be a critical part of our society, their use will become even more widespread. Costs will continue to decrease with larger and larger screens being launched into production every year. This means there will be more applications that require their operation in extreme environments, including the low-temperature regions of the world. By incorporating design measures to mitigate the effects of cold on LCD displays, they can be used virtually anywhere. But this doesn’t come easy. Engineers must understand the design limitations and ways to address the overarching design challenges.

A full-service manufacturing partner like Epec offers a high-value solution to be able to design, develop, and manufacture systems that push the limits of off-the-shelf hardware like LCD displays. This fact helps lower the effective program cost and decreases the time to market for any high-risk development project.

There are several industrial applications that require LCD displays to operate in extreme temperature environments such as in military, food processing, gas/fuel pumps, medical, manufacturing, and non-climate-controlled facilities, among others. Take note that typical monitors can only be used in environments with 0�C~50�C temperature range. UV exposure, moisture, and humidity also affect the overall temperature within a specific environment. iTech Company offers a range of LCD monitors that can function properly in a wide working temperature range from -30℃ to +80℃. These products are already proven and tested to maintain its original luminance under such temperatures.

While the range of operating temperature is a relevant consideration for the device to withstand extreme hot or cold environments, other factors must also be taken into account for the overall performance of the device. These includethe clarity of the image, environmental protection, LED backlighting, quality of the components, andvarious options available.

iTech Company’s products are equipped with these useful features to deliver great performance even in harsh working conditions. These are available in different monitor sizes and resolutions. It offers superior image quality with wide viewing angle. Some of the optional features include the touch screen functionality for interactive application and the level of brightness to ensure that the screen content is highly visible in all lighting conditions. Moreover, these wide operating temperature LCD displays are available in different types including open frame, panel mount, andchassis mount.

Just like when your glasses will fog up when you come in from cold weather, moisture will build on surfaces inside the plant when temperatures go from very cold to very warm. Electronics that suffer this build-up of moisture can have failures related to corrosion. One way to prevent a moisture related failure is waiting a few hours before powering on electronics that have been kept in cold weather after a warm up has occurred. This will allow any condensation to dry before electricity is conducted.

While normally a cool environment is preferable to a warm one when it comes to keeping your electronics up and running, if it gets too cold, certain components can suffer sudden failure. For instance, LCD screens contain fluid and at extreme temperatures can freeze. If you live in the extreme north where temperatures can get into the negatives, it is important to understand the failure limits of your devices which should be available in the manual when you purchase the device. In addition, any electronics that rely on movement such as motors, disk drives, servo valves etc., can suffer failure from the cold. As the temperature drops, metal contracts making moving parts run under higher load stress which can cause the part to fail.

To understand what happens to the LCD in cold temperatures, we"ll need to go back to the basics of LCD technology. Liquid crystal displays are just like their name suggests... they contain a liquid that is housed between two layers of glass. Liquids begin to freeze as the temperature drops. As the liquid in the display freezes the response time slows down. In other words, it takes longer for the numbers and letters on the display to change (Turn ON or Turn OFF).

The best way I can think to explain the response time of the LCD in cold temperatures is a ceiling fan. When you turn OFF the ceiling fan the blades continue to turn for a few minutes, even though the power if OFF. When you turn ON a ceiling fan the blades will be at full speed in a shorter period of time. At most the blades will be at their max speed within 30 seconds. When talking about an LCD, we talk about when the display is ON (the characters can be seen) or OFF (the characters cannot be seen).

Line ‘A’ (image above) displays the amount of time it takes for a character or segment on the display to turn OFF. That is, once you turn OFF the segment, how long does it take before it disappears? The graph above shows that the character actually ‘disappears’ 3500 milliseconds (3.5 seconds) after the display is turned OFF.

Line ‘B’ (image above) displays the amount of time it takes for the character or segment to turn ON. In the above graph the segment is only 55% ‘ON’ at 8000 milliseconds (8 seconds). That means the character is only ½ (half) ON. It will look grey and not very dark. It requires more time for the display to turn ON than to turn OFF… just the opposite of a ceiling fan.

We do not recommend operating our wide temperature (extended temperature) displays below -20°C (-4°F). This is true for all segment displays (static displays or glass displays), 7 (seven) segment, 14 (fourteen) segment, and 16 (sixteen) segment LCD’s.

Alphanumeric LCD displays such as: 8x1 LCD display, 8x2 LCD display, 16x1 LCD display, 16x2 LCD display, 16x4 LCD display, 20x2 LCD display, 20x4 LCD display, 24x2 LCD display, 40x1 LCD display, 40x2 LCD display, and 40x4 LCD display will react the same way.

If you’re moving during cold weather, the low temperature can take a toll on your TV and other electronics. Taking steps to secure and pack these items carefully can help ward off damage and ensure that your television and other gadgets work as intended. These devices are designed to remain at room temperature and have difficulty withstanding severe heat and cold.

First, consult your TV’s owner’s manual, which will provide valuable information about the correct operating and storage temperature for your TV. In many cases, the manufacturer may recommend waiting for the TV to warm up after cold exposure before you plug it in.

Even if this is not specified, you may want to wait several hours to plug in electronics after moving them in the cold.LCD TVsare particularly susceptible to this type of damage. If they are plugged in a while still cold, the liquid crystal screen can freeze and crack, potentially damaging other components of the television.

If you need to store electronics for a specific period, opt for a climate-controlled storage unit so you can easily adjust the temperature to manufacturer specifications. This also prevents damage caused by humidity and moisture accumulation.

Traditional tube-based TVs are susceptible to moisture in the air which causes condensation. Avoid the issue by giving the set time to adjust to the warmer indoor temperatures before you plug it in. Although these TVs may operate at colder temperatures, you might notice interference and other issues.

Even if you hire movers, they might not know the recommendations for your specific devices. For this reason, you should keep your owner’s manual handy and consult them whenever you’re moving your TV and other electronics in extreme temperatures.

I think Aqua and Jeff are on to something here.There are many LCD screens that are left in freezing temps all the time with no damage at all.Jeff has a point about condensation accumulating in the component and a resutling short when powered up.I"m doing some research on this one.

LCD monitors freeze at low temperatures: Well, at some point, everything will freeze! But the liquid-crystal paste used in LCD displays has a different specific gravity than water, and its freezing point is much lower as a result. I have left consumer and professional LCD monitors out in cars overnight when temperatures dropped into the low ‘teens with no adverse effects the next day. (Be nice to the monitor and let it warm up to room temperature before use.)

Keep in mind that many of the displays in today’s cars use LCD technology, in particular car radios and CD players. When was the last time you saw one of those crack when left out in cold weather?

I have a romte cabin which i run with generators. it is not used in winter months and it is not heated or insulated . will my lcd tv get damaged by the cold if i do not bring it home for the winter months. Does any body know?????

Contrary to popular belief, LCD (Liquid Crystal Display) Technology does not involve any sort of liquid whatsoever. LCD panels use tiny microchips that "twist" open to allow light to pass through the display to your eyes. There is no risk of these Crystal "twisters" to freeze. They can get cold, and their "twisting" can be reduced however, but that"s about it. I do suggest allow the tv to warm up before use. The answer to your questions would be like asking if it is ok to leave a calculator in a cabin for the winter. Calculators use the same "LCD" technology, and of course, I"m sure the one you left at the cabin last year still works just fine. No worries. Don"t forget to rate me. Dan 15 Years Home theatre/Tv sales Management

On a side note, keep in mind, lcd technology has been around for over 50 years (invented by sharp) and the technology is used everywhere, like your car dashboard, boeing 747 airplane control panels, laptops. All these items can and will be exposed to freezing temperatures at some time in their lives, and they are still "Living"

Outdoor LCD signage is still in the early phases of adoption across the digital signage industry and there’s still not a lot of common knowledge around it. You’d think our experience with indoor digital signage would transfer to outdoors, but in reality the divide between two is wider than you’d expect. Think about it, your average indoor signage operates in a bubble – regulated temperature, low humidity, indoor light levels, clean air, consistent power, and little chance of vandalism. Outdoors, everything is different.

Outdoor digital displays have to be able to withstand direct sunlight, extreme temperatures, heavy humidity, rain, snow, dust, dirt, wind, and vandalism. How this is achieved varies by who you chose to work with. Before going too far with any outdoor LCD display supplier, here are some considerations for outdoor LCD displays:

Direct sunlight can cause the liquid crystal to boil and result in black blotching on the display, a phenomenon called Solar Clearing. The LCD needs to remain below this boiling point, which requires some mechanism for cooling the LCD.

Displays have to regulate internal temperature to produce a bright picture. If a display cannot keep cool on hot days, or keep warm in cold conditions, brightness will drop-off.

How exactly do you cool the display? A/C systems drip condensation inside and outside the display, require maintenance, and consume significant energy. How do you heat the display in freezing conditions?

The display must be sealed to prevent condensation inside the cover glass and protect internal electronics from getting wet. This means the display needs to work in rain, sleet, snow, and hot, humid summertime. Putting an LCD screen inside an environmentally sealed box is almost always a poor solution.

In the event of a power outage, what happens to the display? First of all, does the display let you know that it has lost power? When power is restored, does the display automatically boot back up and resume showing content?

If you’re not physically present to see the display running, how can you be sure it is actually showing content? Can it detect stalled video signal? Can it alert you when the screen is black?

How easy is it to service the display in the event a component needs repairing? Will it take a service call to find out what’s wrong and then a second trip to repair it? How much will that cost compared to fixing it remotely via software or with just one service call?

There are many more questions to ask and things to consider other than what’s been brought up here regarding outdoor LCD displays. Hopefully this introduction has helped make clear that true outdoor digital displays are not re-packaged indoor displays. If you start thinking about sun, heat, cold, and humidity then you’re well on your way to finding out just how different the indoor and outdoor display environment really is.

Every new motorhome and most new 5th wheel and travel trailers have at least one LCD TV. Many have 2 or more.  The bigger LCD TVs on board RVs and motorhomes have 40-inch screens (or larger).

Today’s technology has come to the point where, for the most part, you will find LCD (or Liquid Crystal Display televisions) being installed almost exclusively in new recreational vehicles.

LCDs are a great choice inside RVs for a number of reasons.  For one, the picture quality is very good.  Plus, they’re not big and bulky like the TVs of yesterday. In fact, some are so thin you can actually mount them on the wall like a picture. LCD flat-screen TVs are even being mounted on motorized bases that retract up flush to the ceiling when not in use.

There is a liquid-based material within the screen of LCD TVs.  Will it be damaged overnight in freezing weather?  Worse yet, if left in storage through the winter in the northern states where temperatures can get bitterly cold, will an LCD flat-screen TV survive?

This means that if your LCD TV is kept in an environment below this range, you must allow it at least 24 hours to acclimate to the proper operating range before you plug it in or turn it on.

When something cold is brought into a warm environment, condensation (or moisture) will be present throughout the device.  Plugging it in or turning it on could result in short circuits, shock, or other catastrophic failure of the unit. If the LCD screen is chilled, even though not frozen, it could fail as well.

Manufacturer limitations on cold storage of their LCD TVs varies all over the map.  Some are rated to handle temps as low as -15F to -20F below zero, while others are barely rated to be stored anywhere near the zero mark.

I was unable to find a single supplier of LCD televisions that would stand behind their product when stored in temperatures lower then the -20F below zero mark.

I live in Minnesota. International Falls, MN is well known as “the ice box of the nation.”  During the very long winter months, temperatures drop to a -40F below quite often. I’ve personally experienced -60F below temperatures, though admittedly only once in my lifetime.

You can remove your LCD televisions from the RV (and I would consider removing VCRs, DVDs, and satellite receivers too), and store them indoors in warmer temperatures.

How long will your LED display last? In nearly every industry, from retail businesses to concert halls to corporate centers, decision makers need to evaluate the return on investment (ROI) of their LED signage. In most cases, potential buyers go straight to the obvious place: the LED manufacturer’s spec sheet. The industry standard for LED lifespan is 100,000 hours, or about 10 years, and most people assume that’s how long their display will last. But it’s not quite that simple.

The 100,000-hour figure assumes that every diode will be running at full brightness, consistently — which, on an LED screen, is virtually never the case. The lifespan figure can also be misleading because it indicates when a diode degrades to half-brightness, not completely dark. Many other variables affect an LED display’s lifespan; you can’t rely solely on the number on the diode spec sheet.

“The reality is, your screen can often last significantly longer than 100,000 hours,” says Kevin Izatt, a senior product manager in Samsung’s Display division. “We’ve had displays that have been up for 15-plus years with more than adequate brightness. Because the diode is actually only one factor in the lifespan of your LED display.”

The biggest contributor to diode degradation is heat. As you increase a diode’s brightness, it produces more heat. Your display’s physical environment also contributes to the temperature of the diodes, especially for outdoor displays.

“Let’s say you’re in Vegas — Death Valley. The diode is fine to operate at those temperatures, but it will degrade faster,” says Izatt. “Temperature is a big factor — and not one you have control over.”

The quality of your display’s power supply — and how hard it drives the diodes — can have a significant impact on your screen’s lifespan. The other components being powered, such as fans and electrical components, have their own lifespans as well, which are also impacted by the power supply.

“Fans are mechanical; they break down,” explains Izatt. “And similar to your computer, the electrical components don’t last forever. Together, these factors all contribute to the lifespan of an LED display. Looking at just the diode lifespan doesn’t give you the complete story — almost always, another part will go out first.”

It’s easy to see why: The circuit boards powering the display release heat, and that heat needs to go somewhere. Without a strong design, thermal stress will degrade the life of the display, except for the highest-quality parts — optimal conditions notwithstanding.

That’s not to say you should hold back on displaying rich, vibrant colors — after all, that’s what LED does best. But it does factor into your product’s life expectancy.

To help businesses transition from LCD to longer-lasting LED signage, Samsung has launched a trade-in program. Samsung will come on site to remove your existing display and provide a discount on a new LED bundle kit.

Traded-in LCD displays that are still operating will be refurbished and resold, and your business will receive a cash rebate. Nonworking displays will be recycled and their parts reused.

You can’t rely on the number on the diode spec sheet; the lifespan of your LED display depends on many more factors. “Overall quality has a tremendous impact on the life of the display that diode specs just don’t take into account,” says Izatt. Your best bet is to look at the purchase holistically and invest in a top-tier product.

As you plan your LED signage rollout — or an upgrade — learn how to configure and tailor your screens’ real-time messaging with an integrated CMS in thisfree guide. And if you haven’t decided what kind of display is best suited to your current project, compare all ofSamsung’s LED displays.

5.At the same time led temperature display panel can also be used in classrooms, hospitals, offices, warehouses, archives, and other places where temperature and humidity are required.

Glass substrate with ITO electrodes. The shapes of these electrodes will determine the shapes that will appear when the LCD is switched ON. Vertical ridges etched on the surface are smooth.

A liquid-crystal display (LCD) is a flat-panel display or other electronically modulated optical device that uses the light-modulating properties of liquid crystals combined with polarizers. Liquid crystals do not emit light directlybacklight or reflector to produce images in color or monochrome.seven-segment displays, as in a digital clock, are all good examples of devices with these displays. They use the same basic technology, except that arbitrary images are made from a matrix of small pixels, while other displays have larger elements. LCDs can either be normally on (positive) or off (negative), depending on the polarizer arrangement. For example, a character positive LCD with a backlight will have black lettering on a background that is the color of the backlight, and a character negative LCD will have a black background with the letters being of the same color as the backlight. Optical filters are added to white on blue LCDs to give them their characteristic appearance.

LCDs are used in a wide range of applications, including LCD televisions, computer monitors, instrument panels, aircraft cockpit displays, and indoor and outdoor signage. Small LCD screens are common in LCD projectors and portable consumer devices such as digital cameras, watches, calculators, and mobile telephones, including smartphones. LCD screens have replaced heavy, bulky and less energy-efficient cathode-ray tube (CRT) displays in nearly all applications. The phosphors used in CRTs make them vulnerable to image burn-in when a static image is displayed on a screen for a long time, e.g., the table frame for an airline flight schedule on an indoor sign. LCDs do not have this weakness, but are still susceptible to image persistence.

Each pixel of an LCD typically consists of a layer of molecules aligned between two transparent electrodes, often made of Indium-Tin oxide (ITO) and two polarizing filters (parallel and perpendicular polarizers), the axes of transmission of which are (in most of the cases) perpendicular to each other. Without the liquid crystal between the polarizing filters, light passing through the first filter would be blocked by the second (crossed) polarizer. Before an electric field is applied, the orientation of the liquid-crystal molecules is determined by the alignment at the surfaces of electrodes. In a twisted nematic (TN) device, the surface alignment directions at the two electrodes are perpendicular to each other, and so the molecules arrange themselves in a helical structure, or twist. This induces the rotation of the polarization of the incident light, and the device appears gray. If the applied voltage is large enough, the liquid crystal molecules in the center of the layer are almost completely untwisted and the polarization of the incident light is not rotated as it passes through the liquid crystal layer. This light will then be mainly polarized perpendicular to the second filter, and thus be blocked and the pixel will appear black. By controlling the voltage applied across the liquid crystal layer in each pixel, light can be allowed to pass through in varying amounts thus constituting different levels of gray.

The chemical formula of the liquid crystals used in LCDs may vary. Formulas may be patented.Sharp Corporation. The patent that covered that specific mixture expired.

Most color LCD systems use the same technique, with color filters used to generate red, green, and blue subpixels. The LCD color filters are made with a photolithography process on large glass sheets that are later glued with other glass sheets containing a TFT array, spacers and liquid crystal, creating several color LCDs that are then cut from one another and laminated with polarizer sheets. Red, green, blue and black photoresists (resists) are used. All resists contain a finely ground powdered pigment, with particles being just 40 nanometers across. The black resist is the first to be applied; this will create a black grid (known in the industry as a black matrix) that will separate red, green and blue subpixels from one another, increasing contrast ratios and preventing light from leaking from one subpixel onto other surrounding subpixels.Super-twisted nematic LCD, where the variable twist between tighter-spaced plates causes a varying double refraction birefringence, thus changing the hue.

LCD in a Texas Instruments calculator with top polarizer removed from device and placed on top, such that the top and bottom polarizers are perpendicular. As a result, the colors are inverted.

The optical effect of a TN device in the voltage-on state is far less dependent on variations in the device thickness than that in the voltage-off state. Because of this, TN displays with low information content and no backlighting are usually operated between crossed polarizers such that they appear bright with no voltage (the eye is much more sensitive to variations in the dark state than the bright state). As most of 2010-era LCDs are used in television sets, monitors and smartphones, they have high-resolution matrix arrays of pixels to display arbitrary images using backlighting with a dark background. When no image is displayed, different arrangements are used. For this purpose, TN LCDs are operated between parallel polarizers, whereas IPS LCDs feature crossed polarizers. In many applications IPS LCDs have replaced TN LCDs, particularly in smartphones. Both the liquid crystal material and the alignment layer material contain ionic compounds. If an electric field of one particular polarity is applied for a long period of time, this ionic material is attracted to the surfaces and degrades the device performance. This is avoided either by applying an alternating current or by reversing the polarity of the electric field as the device is addressed (the response of the liquid crystal layer is identical, regardless of the polarity of the applied field).

Displays for a small number of individual digits or fixed symbols (as in digital watches and pocket calculators) can be implemented with independent electrodes for each segment.alphanumeric or variable graphics displays are usually implemented with pixels arranged as a matrix consisting of electrically connected rows on one side of the LC layer and columns on the other side, which makes it possible to address each pixel at the intersections. The general method of matrix addressing consists of sequentially addressing one side of the matrix, for example by selecting the rows one-by-one and applying the picture information on the other side at the columns row-by-row. For details on the various matrix addressing schemes see passive-matrix and active-matrix addressed LCDs.

LCDs are manufactured in cleanrooms borrowing techniques from semiconductor manufacturing and using large sheets of glass whose size has increased over time. Several displays are manufactured at the same time, and then cut from the sheet of glass, also known as the mother glass or LCD glass substrate. The increase in size allows more displays or larger displays to be made, just like with increasing wafer sizes in semiconductor manufacturing. The glass sizes are as follows:

Until Gen 8, manufacturers would not agree on a single mother glass size and as a result, different manufacturers would use slightly different glass sizes for the same generation. Some manufacturers have adopted Gen 8.6 mother glass sheets which are only slightly larger than Gen 8.5, allowing for more 50 and 58 inch LCDs to be made per mother glass, specially 58 inch LCDs, in which case 6 can be produced on a Gen 8.6 mother glass vs only 3 on a Gen 8.5 mother glass, significantly reducing waste.AGC Inc., Corning Inc., and Nippon Electric Glass.

The origins and the complex history of liquid-crystal displays from the perspective of an insider during the early days were described by Joseph A. Castellano in Liquid Gold: The Story of Liquid Crystal Displays and the Creation of an Industry.IEEE History Center.Peter J. Wild, can be found at the Engineering and Technology History Wiki.

In 1922, Georges Friedel described the structure and properties of liquid crystals and classified them in three types (nematics, smectics and cholesterics). In 1927, Vsevolod Frederiks devised the electrically switched light valve, called the Fréedericksz transition, the essential effect of all LCD technology. In 1936, the Marconi Wireless Telegraph company patented the first practical application of the technology, "The Liquid Crystal Light Valve". In 1962, the first major English language publication Molecular Structure and Properties of Liquid Crystals was published by Dr. George W. Gray.RCA found that liquid crystals had some interesting electro-optic characteristics and he realized an electro-optical effect by generating stripe-patterns in a thin layer of liquid crystal material by the application of a voltage. This effect is based on an electro-hydrodynamic instability forming what are now called "Williams domains" inside the liquid crystal.

In 1964, George H. Heilmeier, then working at the RCA laboratories on the effect discovered by Williams achieved the switching of colors by field-induced realignment of dichroic dyes in a homeotropically oriented liquid crystal. Practical problems with this new electro-optical effect made Heilmeier continue to work on scattering effects in liquid crystals and finally the achievement of the first operational liquid-crystal display based on what he called the George H. Heilmeier was inducted in the National Inventors Hall of FameIEEE Milestone.

In the late 1960s, pioneering work on liquid crystals was undertaken by the UK"s Royal Radar Establishment at Malvern, England. The team at RRE supported ongoing work by George William Gray and his team at the University of Hull who ultimately discovered the cyanobiphenyl liquid crystals, which had correct stability and temperature properties for application in LCDs.

The idea of a TFT-based liquid-crystal display (LCD) was conceived by Bernard Lechner of RCA Laboratories in 1968.dynamic scattering mode (DSM) LCD that used standard discrete MOSFETs.

On December 4, 1970, the twisted nematic field effect (TN) in liquid crystals was filed for patent by Hoffmann-LaRoche in Switzerland, (Swiss patent No. 532 261) with Wolfgang Helfrich and Martin Schadt (then working for the Central Research Laboratories) listed as inventors.Brown, Boveri & Cie, its joint venture partner at that time, which produced TN displays for wristwatches and other applications during the 1970s for the international markets including the Japanese electronics industry, which soon produced the first digital quartz wristwatches with TN-LCDs and numerous other products. James Fergason, while working with Sardari Arora and Alfred Saupe at Kent State University Liquid Crystal Institute, filed an identical patent in the United States on April 22, 1971.ILIXCO (now LXD Incorporated), produced LCDs based on the TN-effect, which soon superseded the poor-quality DSM types due to improvements of lower operating voltages and lower power consumption. Tetsuro Hama and Izuhiko Nishimura of Seiko received a US patent dated February 1971, for an electronic wristwatch incorporating a TN-LCD.

In 1972, the concept of the active-matrix thin-film transistor (TFT) liquid-crystal display panel was prototyped in the United States by T. Peter Brody"s team at Westinghouse, in Pittsburgh, Pennsylvania.Westinghouse Research Laboratories demonstrated the first thin-film-transistor liquid-crystal display (TFT LCD).high-resolution and high-quality electronic visual display devices use TFT-based active matrix displays.active-matrix liquid-crystal display (AM LCD) in 1974, and then Brody coined the term "active matrix" in 1975.

In 1972 North American Rockwell Microelectronics Corp introduced the use of DSM LCDs for calculators for marketing by Lloyds Electronics Inc, though these required an internal light source for illumination.Sharp Corporation followed with DSM LCDs for pocket-sized calculators in 1973Seiko and its first 6-digit TN-LCD quartz wristwatch, and Casio"s "Casiotron". Color LCDs based on Guest-Host interaction were invented by a team at RCA in 1968.TFT LCDs similar to the prototypes developed by a Westinghouse team in 1972 were patented in 1976 by a team at Sharp consisting of Fumiaki Funada, Masataka Matsuura, and Tomio Wada,

In 1983, researchers at Brown, Boveri & Cie (BBC) Research Center, Switzerland, invented the passive matrix-addressed LCDs. H. Amstutz et al. were listed as inventors in the corresponding patent applications filed in Switzerland on July 7, 1983, and October 28, 1983. Patents were granted in Switzerland CH 665491, Europe EP 0131216,

The first color LCD televisions were developed as handheld televisions in Japan. In 1980, Hattori Seiko"s R&D group began development on color LCD pocket televisions.Seiko Epson released the first LCD television, the Epson TV Watch, a wristwatch equipped with a small active-matrix LCD television.dot matrix TN-LCD in 1983.Citizen Watch,TFT LCD.computer monitors and LCD televisions.3LCD projection technology in the 1980s, and licensed it for use in projectors in 1988.compact, full-color LCD projector.

In 1990, under different titles, inventors conceived electro optical effects as alternatives to twisted nematic field effect LCDs (TN- and STN- LCDs). One approach was to use interdigital electrodes on one glass substrate only to produce an electric field essentially parallel to the glass substrates.Germany by Guenter Baur et al. and patented in various countries.Hitachi work out various practical details of the IPS technology to interconnect the thin-film transistor array as a matrix and to avoid undesirable stray fields in between pixels.

Hitachi also improved the viewing angle dependence further by optimizing the shape of the electrodes (Super IPS). NEC and Hitachi become early manufacturers of active-matrix addressed LCDs based on the IPS technology. This is a milestone for implementing large-screen LCDs having acceptable visual performance for flat-panel computer monitors and television screens. In 1996, Samsung developed the optical patterning technique that enables multi-domain LCD. Multi-domain and In Plane Switching subsequently remain the dominant LCD designs through 2006.South Korea and Taiwan,

In 2007 the image quality of LCD televisions surpassed the image quality of cathode-ray-tube-based (CRT) TVs.LCD TVs were projected to account 50% of the 200 million TVs to be shipped globally in 2006, according to Displaybank.Toshiba announced 2560 × 1600 pixels on a 6.1-inch (155 mm) LCD panel, suitable for use in a tablet computer,

In 2016, Panasonic developed IPS LCDs with a contrast ratio of 1,000,000:1, rivaling OLEDs. This technology was later put into mass production as dual layer, dual panel or LMCL (Light Modulating Cell Layer) LCDs. The technology uses 2 liquid crystal layers instead of one, and may be used along with a mini-LED backlight and quantum dot sheets.

Since LCDs produce no light of their own, they require external light to produce a visible image.backlight. Active-matrix LCDs are almost always backlit.Transflective LCDs combine the features of a backlit transmissive display and a reflective display.

CCFL: The LCD panel is lit either by two cold cathode fluorescent lamps placed at opposite edges of the display or an array of parallel CCFLs behind larger displays. A diffuser (made of PMMA acrylic plastic, also known as a wave or light guide/guiding plateinverter to convert whatever DC voltage the device uses (usually 5 or 12 V) to ≈1000 V needed to light a CCFL.

EL-WLED: The LCD panel is lit by a row of white LEDs placed at one or more edges of the screen. A light diffuser (light guide plate, LGP) is then used to spread the light evenly across the whole display, similarly to edge-lit CCFL LCD backlights. The diffuser is made out of either PMMA plastic or special glass, PMMA is used in most cases because it is rugged, while special glass is used when the thickness of the LCD is of primary concern, because it doesn"t expand as much when heated or exposed to moisture, which allows LCDs to be just 5mm thick. Quantum dots may be placed on top of the diffuser as a quantum dot enhancement film (QDEF, in which case they need a layer to be protected from heat and humidity) or on the color filter of the LCD, replacing the resists that are normally used.

WLED array: The LCD panel is lit by a full array of white LEDs placed behind a diffuser behind the panel. LCDs that use this implementation will usually have the ability to dim or completely turn off the LEDs in the dark areas of the image being displayed, effectively increasing the contrast ratio of the display. The precision with which this can be done will depend on the number of dimming zones of the display. The more dimming zones, the more precise the dimming, with less obvious blooming artifacts which are visible as dark grey patches surrounded by the unlit areas of the LCD. As of 2012, this design gets most of its use from upscale, larger-screen LCD televisions.

RGB-LED array: Similar to the WLED array, except the panel is lit by a full array of RGB LEDs. While displays lit with white LEDs usually have a poorer color gamut than CCFL lit displays, panels lit with RGB LEDs have very wide color gamuts. This implementation is most popular on professional graphics editing LCDs. As of 2012, LCDs in this category usually cost more than $1000. As of 2016 the cost of this category has drastically reduced and such LCD televisions obtained same price levels as the former 28" (71 cm) CRT based categories.

Monochrome LEDs: such as red, green, yellow or blue LEDs are used in the small passive monochrome LCDs typically used in clocks, watches and small appliances.

Today, most LCD screens are being designed with an LED backlight instead of the traditional CCFL backlight, while that backlight is dynamically controlled with the video information (dynamic backlight control). The combination with the dynamic backlight control, invented by Philips researchers Douglas Stanton, Martinus Stroomer and Adrianus de Vaan, simultaneously increases the dynamic range of the display system (also marketed as HDR, high dynamic range television or FLAD, full-area local area dimming).

The LCD backlight systems are made highly efficient by applying optical films such as prismatic structure (prism sheet) to gain the light into the desired viewer directions and reflective polarizing films that recycle the polarized light that was formerly absorbed by the first polarizer of the LCD (invented by Philips researchers Adrianus de Vaan and Paulus Schaareman),

A pink elastomeric connector mating an LCD panel to circuit board traces, shown next to a centimeter-scale ruler. The conductive and insulating layers in the black stripe are very small.

A standard television receiver screen, a modern LCD panel, has over six million pixels, and they are all individually powered by a wire network embedded in the screen. The fine wires, or pathways, form a grid with vertical wires across the whole screen on one side of the screen and horizontal wires across the whole screen on the other side of the screen. To this grid each pixel has a positive connection on one side and a negative connection on the other side. So the total amount of wires needed for a 1080p display is 3 x 1920 going vertically and 1080 going horizontally for a total of 6840 wires horizontally and vertically. That"s three for red, green and blue and 1920 columns of pixels for each color for a total of 5760 wires going vertically and 1080 rows of wires going horizontally. For a panel that is 28.8 inches (73 centimeters) wide, that means a wire density of 200 wires per inch along the horizontal edge.

The LCD panel is powered by LCD drivers that are carefully matched up with the edge of the LCD panel at the factory level. The drivers may be installed using several methods, the most common of which are COG (Chip-On-Glass) and TAB (Tape-automated bonding) These same principles apply also for smartphone screens that are much smaller than TV screens.anisotropic conductive film or, for lower densities, elastomeric connectors.

Monochrome and later color passive-matrix LCDs were standard in most early laptops (although a few used plasma displaysGame Boyactive-matrix became standard on all laptops. The commercially unsuccessful Macintosh Portable (released in 1989) was one of the first to use an active-matrix display (though still monochrome). Passive-matrix LCDs are still used in the 2010s for applications less demanding than laptop computers and TVs, such as inexpensive calculators. In particular, these are used on portable devices where less information content needs to be displayed, lowest power consumption (no backlight) and low cost are desired or readability in direct sunlight is needed.

A comparison between a blank passive-matrix display (top) and a blank active-matrix display (bottom). A passive-matrix display can be identified when the blank background is more grey in appearance than the crisper active-matrix display, fog appears on all edges of the screen, and while pictures appear to be fading on the screen.

Displays having a passive-matrix structure are employing Crosstalk between activated and non-activated pixels has to be handled properly by keeping the RMS voltage of non-activated pixels below the threshold voltage as discovered by Peter J. Wild in 1972,

STN LCDs have to be continuously refreshed by alternating pulsed voltages of one polarity during one frame and pulses of opposite polarity during the next frame. Individual pixels are addressed by the corresponding row and column circuits. This type of display is called response times and poor contrast are typical of passive-matrix addressed LCDs with too many pixels and driven according to the "Alt & Pleshko" drive scheme. Welzen and de Vaan also invented a non RMS drive scheme enabling to drive STN displays with video rates and enabling to show smooth moving video images on an STN display.

Bistable LCDs do not require continuous refreshing. Rewriting is only required for picture information changes. In 1984 HA van Sprang and AJSM de Vaan invented an STN type display that could be operated in a bistable mode, enabling extremely high resolution images up to 4000 lines or more using only low voltages.

High-resolution color displays, such as modern LCD computer monitors and televisions, use an active-matrix structure. A matrix of thin-film transistors (TFTs) is added to the electrodes in contact with the LC layer. Each pixel has its own dedicated transistor, allowing each column line to access one pixel. When a row line is selected, all of the column lines are connected to a row of pixels and voltages corresponding to the picture information are driven onto all of the column lines. The row line is then deactivated and the next row line is selected. All of the row lines are selected in sequence during a refresh operation. Active-matrix addressed displays look brighter and sharper than passive-matrix addressed displays of the same size, and generally have quicker response times, producing much better images. Sharp produces bistable reflective LCDs with a 1-bit SRAM cell per pixel that only requires small amounts of power to maintain an image.

Segment LCDs can also have color by using Field Sequential Color (FSC LCD). This kind of displays have a high speed passive segment LCD panel with an RGB backlight. The backlight quickly changes color, making it appear white to the naked eye. The LCD panel is synchronized with the backlight. For example, to make a segment appear red, the segment is only turned ON when the backlight is red, and to make a segment appear magenta, the segment is turned ON when the backlight is blue, and it continues to be ON while the backlight becomes red, and it turns OFF when the backlight becomes green. To make a segment appear black, the segment is always turned ON. An FSC LCD divides a color image into 3 images (one Red, one Green and one Blue) and it displays them in order. Due to persistence of vision, the 3 monochromatic images appear as one color image. An FSC LCD needs an LCD panel with a refresh rate of 180 Hz, and the response time is reduced to just 5 milliseconds when compared with normal STN LCD panels which have a response time of 16 milliseconds.

Samsung introduced UFB (Ultra Fine & Bright) displays back in 2002, utilized the super-birefringent effect. It has the luminance, color gamut, and most of the contrast of a TFT-LCD, but only consumes as much power as an STN display, according to Samsung. It was being used in a variety of Samsung cellular-telephone models produced until late 2006, when Samsung stopped producing UFB displays. UFB displays were also used in certain models of LG mobile phones.

Twisted nematic displays contain liquid crystals that twist and untwist at varying degrees to allow light to pass through. When no voltage is applied to a TN liquid crystal cell, polarized light passes through the 90-degrees twisted LC layer. In proportion to the voltage applied, the liquid crystals untwist changing the polarization and blocking the light"s path. By properly adjusting the level of the voltage almost any gray level or transmission can be achieved.

In-plane switching is an LCD technology that aligns the liquid crystals in a plane parallel to the glass substrates. In this method, the electrical field is applied through opposite electrodes on the same glass substrate, so that the liquid crystals can be reoriented (switched) essentially in the same plane, although fringe fields inhibit a homogeneous reorientation. This requires two transistors for each pixel instead of the single transistor needed for a standard thin-film transistor (TFT) display. The IPS technology is used in everything from televisions, computer monitors, and even wearable devices, especially almost all LCD smartphone panels are IPS/FFS mode. IPS displays belong to the LCD panel family screen types. The other two types are VA and TN. Before LG Enhanced IPS was introduced in 2001 by Hitachi as 17" monitor in Market, the additional transistors resulted in blocking more transmission area, thus requiring a brighter backlight and consuming more power, making this type of display less desirable for notebook computers. Panasonic Himeji G8.5 was using an enhanced version of IPS, also LGD in Korea, then currently the world biggest LCD panel manufacture BOE in China is also IPS/FFS mode TV panel.

In 2015 LG Display announced the implementation of a new technology called M+ which is the addition of white subpixel along with the regular RGB dots in their IPS panel technology.

Most of the new M+ technology was employed on 4K TV sets which led to a controversy after tests showed that the addition of a white sub pixel replacing the traditional RGB structure would reduce the resolution by around 25%. This means that a 4K TV cannot display the full UHD TV standard. The media and internet users later called this "RGBW" TVs because of the white sub pixel. Although LG Display has developed this technology