lcd display temperature limits manufacturer
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.
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.
Modern LCD screens have a great many uses. Not only are they now the system of choice for our home TVs and computers but their use in digital signage has made them a common sight in many shopping malls, airports and other locations with high quantities of people.
Even outdoor locations are no barrier to the use of modern LCD screens with outdoor digital signage a rising medium now seen in many town centers, car parks, front of stores and train station platforms.
All this out of home use means many screens operate in locations test the temperature limits of LCD displays. While waterproof screens and LCD enclosures designed for rugged applications provide the ability of the screen to operate-even in outdoor locations, one consideration often overlooked, is that of temperature.
LCD screens have a limited temperature range. Not only will the electronics inside an TV screen overheat and cause failure if the screen gets too hot, but the liquid crystal itself will begin to deteriorate under hot conditions.
The same is true of environments where temperatures fall below zero, causing a screen to stop functioning. A typical LCD TV has an operating range between 0°C (32°F) and 32°C (90°F).
Of course, many indoor and outdoor locations don’t suffer temperatures outside of this range, but many locations do and placing screens in these areas can prove challenging.
One of the problems with using a screen in hot locations is that the screen itself produces quite a bit of heat. When housed in an outdoor enclosure, the heat has to be continuously removed. While cooling fans combined with an air-vent normally carry out this task on an LCD, the need to prevent moisture from getting to the screen makes the task more complicated.
To get around this problem, specially shaped vents provide an exit for hot air while preventing rainfall and other moisture from getting in. In some locations where ambient temperatures are extremely high, screens need air conditioning to ensure they don’t exceed the maximum operating temperature.
In cold climates the opposite problem occurs. The need to keep heat in often requires insulation of the screen enclosure. Often this can trap enough of the heat generated by the screen itself to keep the internal temperature above minimum, but in some locations, even this isn’t enough. Heaters, controlled by thermostats provide extra heat in these circumstances, which enables the use of LCD displays in extremely cold locations such as ski-resorts and in Arctic regions.
The higher the mux rate, the less time a given group of segments is being addressed , and the worse the display will look. If you refer to our "Basic Operation of an LCD" page, it is easy to see that this is not a good situation.
display will not really damage the contrast and viewing angle very much. For mux rates above 4:1, serious degradation sets in. At that point, a switch of drivers or a move to STN technology are the options.
In cooler climates, the LCD fluid will slow down and change the response time of the display. We can install transparent heater films through an optical bonding process to maintain a sleek and modern display, as well as maintain display response time. The display heater will become active when the built in sensor detects a pre-set ambient temperature. This will protect the display from becoming overheated and conserve display power. We also work with you to ensure your display is in a proper enclosure that will retain the heat generated to prevent battery drainage. E3 enhancements to wide temperature displays can operate in the most rugged environments, maintain battery life, and exceed aesthetic standards.
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.
Typically, standard LCD display provide a temperature range of 0°C to +50°C. However, this temperature range cannot always meet the needs of such usage. Considering the increasing demand of wide temperature range, several display manufacturers offer wide selection of standard versions that range from -20°C to +70°C. Extended Temperature Solutions for Industrial Applications. As a professional LCD manufacturer, we must follow more closely demands in the market. EVERVISION has developed a series of wide temperature TFT LCD modules with operating temperatures ranging from -30°C to +80°C, and the maximum for some models can reach 85°C. For more information, please contact us.
Expanding the operating temperature range is one of EVERVISION"s strategy to improve the performance of industrial TFT product line. The other display improvement is LCD Transparent Heater that provides optimized visual view even in an extremely low temperature environment.
As a solution, EVERVISION integrate the TFT LCD module, transparent heater(Glass Heater) and heater temperature sensor to control and monitor temperature smartly. With our controller system, it could precisely and rapidly adjust the temperature of TFT-LCD module. Also, it can reduce display power consumption.
Typically, standard LCD modules provide a temperature range of -20°C to +70°C. To meet the need of customers, EVERVISION has developed a series of wide temperature TFT LCD modules with operating temperatures ranging from -30°C to +80°C, and the maximum for some models can reach 85°C.
EVERVISION developed LCD Heater to integrate with our TFT Display Module so that can show optimal view even in low temperature. For materials, heaters can be used with transparent resins, such as glass and poly-carbonate. Our LCD Transparent Heater is made of glass substrate, so we name it “Glass Heater”. It can not only improve the LCD image sticking issue efficiently, but also have heat and humidity resistance advantage.
As the result, it shows 4.3 inch TFT LCD Module display functionally under normal operating conditions. However, there is an overlapping at low temperature, because of LC"s physical characteristics. From this experiment, we know that overlapping can be solved by turning on Glass Heater.
In the design of the LCD screen, the selection of what temperature range of liquid crystal materials will be considered. Usually, our TFT LCD screen work is divided into normal temperature 0-50 degrees, wide temperature -20-70 degrees, super-wide temperature -30-80 degrees, even customers will choose -40 degrees of extremely special materials to design. So, does the LCD still work at the limit temperature?
Actually, this question is a little ambiguity, as we know, for example, the wide temperature scope of work is – 20-70 degrees, so first of all, in less than 20 degrees below 0 and higher than 70 degrees of circumstances, the LCD panel will not be able to work in theory, but, if you haven’t reached 70 degrees and the temperature of minus 20 degrees, but already very close to, can be said to be the limiting temperature, the LCD screen can work normally?
This problem is also a problem many customers will put forward, many customers use the wide temperature LCD, in the case of very low temperature, the word becomes very weak, and in the case of very high temperature, the word becomes very deep, how is this?
In fact, the LCD screen goes a long way to explaining the principle, the LCD panel to display all sorts of design or pen, is due to the liquid crystal box of LCD in work, andliquid crystal, just as its name implies is liquid, must be affected by the environment, high-temperature liquid crystal will be fever, flow speed, the feedback is on display, color is very deep. Under the condition of low temperature, the liquid crystal will start to crystallize and flow slowly, and the color on the display will become very shallow. It is not that it cannot display normally, but the display time will be much slower than the normal temperature.
So everyone should be able to understand, the operating temperature of the LCD screen, that is, in this temperature range it is able to work, not because of environmental factors do not display or do not refresh the situation.
Generally speaking, the wide temperature LCD screen, for example, starting from 5 degrees below zero and 50 degrees centigrade, the speed of the display will begin to change, to minus 20 degrees and 70 degrees above freezing, reached the limit temperature, feedback to the screen is no display or a dark state, already can’t use, so liquid crystal often advise clients, if the actual temperature is close to the limit temperature, it must choose a wider temperature range of LCD screen.
STONE has more than 20 years of industrial LCD production experience. STONE HMI solutions are now widely used in a variety of industrial embedded areas of advanced civil products: such as home and office automation, medical equipment, beauty machines, vending machines, power control systems, and excavators.STONE is highly recognized by national instruments, state grid corporation of China, Thyssenkrupp Elevator, and other partners for all kinds of equipment, such as gas stations and charging piles, that require a stable operating temperature of TFT LCD screen and relatively severe operating environment.
The T-57152GD042H-LW-AAN and the T-55923GD050J-LW-ABN, small-format TFT LCD modules designed for use in harsh environments, have been introduced by Kyocera.
The T-57152GD042H-LW-AAN, which measures 4.2”, features a resolution of 480x272px, a brightness of 700cd/m², a digital 18-bit RGB interface, a contrast ratio of 1200:1, and horizontal and vertical viewing angles of 160° each. The design is based on automotive requirements and boasts an expanded operating temperature range of -30 to +85°C and a storage temperature range of -40 to +95°C. In addition, the anti-glare surface treatment improves readability in bright surroundings.
Measuring 5.0”, the T-55923GD050J-LW-ABN is a portrait-mode display that features a resolution of 480x640px. Optical characteristics include 800cd/m² brightness and a 500:1 contrast ratio. The viewing angle amounts to 140º horizontally and 110° vertically. This module comes with a 24-bit digital RGB interface and has a wide operating temperature range of -30 to +80°C.
“Portable outdoor devices are liable to fall down and are exposed to low temperatures, heat and humidity. Even in these conditions, they should always work reliably, and our components are designed for that purpose,” says Eberhard Schill, Manager Distribution and Marketing, Kyocera Display Europe.
According to the popularization of display applications, the TFT LCD display have to adapt the Extreme Temperature and Different EnviromentsFIRST Components/ Evervision’s Wide Temperature TFT LCD Series are designed specifically for operation in harsh environments and under changing temperature. Furthermore, we have a solution for low temperature environment. Let’s find out!
The LCD in cold temperatures may cause misreading because of the response time of LC (physical characteristics). It will turn slowly and make the screen overlap. Additionally, it may cause permanent damage to the display if LCD panel left in such conditions for extended periods.
Fortunately, there are a number of solution such as specialty liquid crytals (LCs) and other materials for application requiring the use of a display in extreme environmental condition. FIRST Components/ Evervision Wide Temperature TFT LCD Display overcome these challenges through the use of applied heating and cooling solutions.
At present, the common TFT LCD modules on the market have a wide range of definitions of -20~70 °C. For industrial control, vehicle and outdoor products, this temperature range always can’t meet the needs of such usage.
Fortunately, our Wide Temperature TFT LCD Display can work under extreme environments with operating temperatures ranging from -30°C to +80°C, and the maximum for some models can reach 85°C. These TFT displays are full color LCDs available in industry standard sizes rangingfrom 3.5″ to 15.6” TFT LCD display and widely used in cold or heat condition throughout the world.
In low temperature environment, liquid crystals will be condensed and cause the screen blanked out. In order to prevent the problem, you may need to add a Glass Heater to your TFT LCD Module.
It can optimize the LCD visual clarity and operate normally by heating up to the right temperature. With Glass Heater, displays and touch screens remain usable in cold, high humidity/low dew point environments and locations where ambient temperature can change quickly.
Amongo delivers a wide range of industrial monitors that meet extended temperature specifications with a operation temperature from -30 to 85℃. With the adoption of our own designed A/D boards, these industrial LCD monitors are a good choice for any indoor or outdoor applications where extreme temperature conditions are to be expected.
LCD panels uses LED backlights to operate. Luminance output of LED lights depends heavily on LCD operating temperature. Lower the temperature higher the brightness performance output.
Noritake’s electronics division has been around since the creation of the Vacuum Fluorescent Display(VFD). We have grown to provide a wide array of products and services to ensure a smooth and efficient development cycle for your application. Our customer support staff will gladly provide you with technical support to assist with your needs.
Microtips’s Automotive Grade LCD Modules are offered in sizes ranging from 3.5 to 12.1 in. with high-brightness backlights. The units are suitable for use in applications such as dials, gauges, clocks and audio/thermostat controls. The LCD modules can be operated in -30 to 85°C and can be either resistive or capacitive. The units use IPS technology for keeping colors accurately vibrant and viewing angles wide.
These LCD Modules, with a standard operating temperature of -30 to 85 degrees Celsius, will allow manufacturers to use these displays in any environment, no matter how harsh the conditions. With an emphasis on robust construction and extended temperature range, these displays are ready to use in automotive applications like dials, gauges, clocks, and audio/thermostat controls. They are available in a variety of sizes ranging from 3.5” to 12.1” with high resolution and can come with high-brightness backlights for sunlight readability. Most utilize the latest IPS technology to keep colors accurately vibrant and viewing angles wide. These displays are available with many different interface technologies such as LVDS and RGB to ensure that our display will work with most controllers. Touch Panels are available on some models which make them perfect for center infotainment consoles. They can be either resistive or capacitive and can be fine tuned to work with gloves if needed. They utilize SPI or I2C to communicate with the host device.