direct sunlight lcd panel quotation
Crystalfontz has a large selection of sunlight readable displays. We carry both graphic sunlight readable LCD displays as well as character sunlight readable LCD displays.
A transflective lcd offers lower power for high ambient light applications, very good sunlight readability, and good balance between indoor and outdoor readability. They perform better under all lighting conditions, especially direct sunlight.
A reflective lcd display has polarizers that are basically a mirror that sits behind the LCD glass reflecting all the light from the sun and redirecting it back towards the user. The brighter the light, the easier it is to read. The downside to a reflective polarizer is that in dark environments, you cannot put a backlight behind it. The reflective polarizer will block any light from reaching the user. If you must have a backlight, you may need to add an edge lit or side lit LED light.
If there is a sunlight readable display you"re not finding here, please talk to our support team, they might be able to find one that will fit your needs.
It is a complex recipe that requires the right balance of key ingredients that include enhanced backlight, optimized internal film stack, front coverglass with correct index matched coatings all integrated into the ideal host LCD panel for the application.
Q-Vio began development of sunlight readable displays over a decade ago and we have continued to push the daylight readable display performance envelop to this day. We provide the highest quality outdoor imaging with the ability to tailor our display technology to your specific requirements. We feature Full HD small size models for portable applications, 4:3 aspect ratio long life panels for industrial, marine and military applications and larger full HD to 4K panels for outdoor digital signage.
For high performance display technology that can stand-up to the brightest sunlight conditions, look no further. Introducing Q-Vio’s family of sunlight readable displays ranging in size from 5”- 32” They “beat the daylight out of sunlight” with ultra bright, easy-to-read displays, even in direct sunlight. Built in a Class 1000 clean-room, these low power, RoHS compliant LED backlit displays offer superior uniformity and outstanding thermal management for fan-less operation.
With original factory display footprint, our high-bright display panels offer an easy upgrade path to sunlight readability. These low power displays are perfect for a wide range of products where size, weight, power and sharp readability in bright sunlight are essential. Outdoor Kiosks, Marine Console monitors, Aviation, monitors for industrial Machinery and Military Display Equipment are just a few of the many applications that can benefit from the power and brightness of Q-Vios truly sunlight readable displays.
To power and control the custom LED backlights, Q-Vio has developed a RoHS compliant LED driver board family that is specifically designed to power up the displays. Their wide dimming range offers a stable, uniform brightness from the extreme low end through true sunlight readable levels.
TRU-Vu High Bright Sunlight Readable Monitors enable users to see clear, sharp video images even in direct sunlight with a bright screen. Our high brightness displays produce at least 1,000 nits brightness. Some go up to 2,500 nits of brightness. This makes them far brighter than standard LCD monitors. Specifically, consumer or commercial-grade monitors typically offer only 150 to 300 nits brightness. High brightness displays and sunlight readable touch screens will ensure crystal-clear video images even in bright sunlight. The result is better performance and bold colors in other high ambient light conditions as well. They are also available with optical bonding as monitors or touch screen displays.
In outdoor or bright conditions, it is imperative to increase the brightness of a display to ensure crisp images. The number of nits an LCD display emits is the main factor in determining the monitor’s perceived brightness. A monitor luminance of around 200-350 nits will work well indoors. Most LCD displays and monitors fall in this range. However, 400-700 nits would be required for use in daylight conditions. Most importantly, a Sunlight readable display requires at least 1,000 nits or more for viewing in direct, bright sunlight . These high brightness displays are available with 16:9 aspect ratio or 4:3 aspect ratio screens. All TRU-Vu Sunlight Readable monitors and high-brightness touch screens are TAA Compliant.
Some monitors feature a sheet of glass over the LCD panel to protect it from accidental or intentional damage. However, the glass also produces unwanted glare and reflections. Internal reflections in the air gap between the glass and the LCD panel diminish image quality even further. In order to combat this, monitors are optically bonded.
Optical bondingis the process of laminating protective glass or a touch screen panel to the LCD panel with an optical-grade resin. This completely fills the air gap between the glass and LCD panel. It not only eliminates the internal reflections, but also increases the contrast ratio. This makes the screen appear much brighter and more viewable in bright light conditions. Optical bonding also eliminates internal moisture and condensation. Moreover, it will make the monitor more rugged and durable. Lastly, an Anti-Reflective coating is applied to the outside of the glass. Consequently, this will drastically reduce glare and surface reflections.
For installations in indirect sunlight, or reflected bright light, our Daylight Viewable displays will most likely suffice. These are also more cost-effective than Sunlight Readable monitors with 1,000 nits brightness. Daylight viewable monitors feature LCD screens with 400 nits to 700 nits brightness. The LCD panels also include optical bonding.
Daylight-viewable touchscreens with optical bonding are also significantly brighter than standard touch screens. Consequently, they produce far better image quality in bright conditions. Although they are not as bright as High Brightness Sunlight Readable touch screens, daylight readable touch screens do offer the benefit of lower power consumption. This may be useful in portable or mobile applications. We currently offer over 60 monitors with optical bonding; all are TAA-Compliant.
Our outdoor high brightness Sunlight Readable LCD monitors feature waterproof stainless steel enclosures. These are ideal for factory wash-down environments. Additionally, they are perfect for outside use in challenging weather. Our panel mount enclosures are made from steel, stainless steel, or aluminum. This enables them to be flush-mounted. Outdoor LCD monitors with high brightness work in a wider range of temperatures. Consequently, this broadens the environments in which they may be used. Additionally, temperature ranges are very important to consider when using outdoors. When we combine extreme operating temperatures with outdoor waterproof enclosures, we ensure your high brightness monitors will be able to function in even the harshest wet and hot environments. We will also modify or customize any model to meet your exact requirements.
In conclusion, we deploy TRU-Vu outdoor waterproof sunlight readable monitors and high brightness touch screens in a wide range of industries. For example, military, law enforcement, manufacturing plants benefit from high bright LCD displays. Amusement parks, sports stadiums, mass transit, and construction & heavy equipment also rely on high bright sunlight readable displays. In addition, outdoor high brightness LCD monitors are demanded in pipeline inspection, kiosks, marine, oil & gas, drones, security applications. When it counts, you can rely on TRU-Vu Monitors to deliver the optimal weather resistant high bright LCD monitor solution for your specific needs.
Sunlight readable TFT displays feature high brightness LCD backlights, making them an excellent option for bright ambient light or direct sunlight environments. Our sunlight readable TFT displays are available with or without touchscreen features and come with different formats and display modes to fit any application.
Before answering the questions below, it would be helpful to provide a simple overview of how a TFT LCD works. Every monitor or touchscreen computer includes an LCD panel. The LCD panel is the component that you are viewing at this very moment. This panel includes a thin layer of TFT LCD pixels, where each pixel includes a red, blue, and green rectangle. You can actually see the individual pixels on a display if you place a drop of water on it. The drop will magnify the pixel area and reveal a pixel with a red, blue, and green rectangle. Each red, blue, and green rectangle is a small lens that can be adjusted to allow varying amounts of light to pass through. The colors you see on your screen are determined by how much light is passing through each adjustable red, green, and blue element of each pixel.
The light that you see does not come from the pixels themselves, but from the backlight behind the pixels, which is a series of carefully placed LEDs that emit white light that projects through the LCD pixels. You cannot see the individual backlight LEDs when you look at your monitor, because there is layer of light diffusing material between the LED backlight and the LCD pixel layer. The light diffusing material scatters the light from each individual backlight LED, so they do not show up as bright spots on your monitor.
To summarize, the three layers of an LCD panel are the TFT LCD pixel layer, the diffuser layer, and the LED backlight layer. Note that some LCDs have edge-lit backlighting, but there is no need to go into detail about this, as the same principles apply. That completes LCD panel course 101. Now, what makes a display sunlight readable?
There are two general ways to make an LCD brighter and therefore readable in sunlight. The first and simplest way is to increase the brightness of the backlight. LCD brightness is measured in Nits. Typical LCD panels have a screen brightness between 250 Nits to 450 Nits. LCD brightness of 800 Nits or higher is generally considered sunlight readable, but most sunlight readable displays are 1000 nits. Increasing the brightness of the LCD panel backlight is the most common method of making an LCD panel sunlight readable. Most of Teguar’s industrial panel PCs and touchscreen monitors are available with this type of high brightness LCD.
Another way to make an LCD sunlight readable is to change the diffuser material between the LED backlight and the LCD pixels to a “transflective” material. The transflective material is similar to reflective sunglasses or a one way window, where the shiny side is facing the LCD surface. When transflective material is used, the sunlight entering the LCD panel travels through the pixels, bounces off the transflective material, and is reflected back through the pixels to your eyes. In this case, the sunlight has much less of an impact on viewability than a traditional LCD panel, as the sunlight is reflecting back through the LCD pixels and contributing to the LCD brightness. One drawback of transflective diffuser LCDs is that they don’t allow for as much of the backlight to pass through the diffuser material, so in low light conditions the LCD does not appear as bright. Transflective diffuser LCDs are not as common as high brightness backlight LCDs.
Optical bonding improves viewability of touchscreen PCs in sunlight or other high-bright environments. In a touchscreen computer, the touchscreen sensor and the LCD panel are separate components. The touchscreen is mounted in front of the LCD surface and there is a small air gap between these two components. When sunlight passes through the touchscreen layer, some amount of the light is reflected between the LCD surface and the touchscreen; this reflection reduces LCD viewability.
Optical bonding is a process where a clear adhesive gel is placed between the LCD to the touchscreen. The gel hardens and bonds the touchscreen to the LCD to eliminate the air gap, improving contrast and clarity. Optical bonding is available on many of Teguar’s touchscreen computers and industrial monitors.
The brightness of a sunlight readable display may be overwhelming at night, when there is little or no ambient light. Most industrial computers with sunlight readable LCDs are available with an optional auto-dimming feature. With this feature, an ambient light sensor on the front bezel measures incoming light and adjusts the backlight brightness to match the current light conditions. This is typically a requirement for industrial touchscreen computers that are used in both sunlight and moonlight.
Sunlight also comes with a high amount of UV radiation that can damage the components used in touch screens. PCAP touch screens resist UV damage better than Resistive, but even a PCAP screen must be protected from too much UV exposure. Teguar computers are best suited for environments that provide some level of shade, such as a roof or overhang above the computer, or a structure that blocks the screen from direct exposure to the sun. Most outdoor computer manufactures, Teguar included, will offer a specialized shroud/hood that mounts directly to the unit to provide some level of shade.
Most of our products can handle a few hours of direct sun exposure per day, but full exposure to direct sunlight will cause damage to most touch screens in around 1 year. Contact a knowledgeable Teguar sales rep to discuss the details of your own environment and we can help determine the best solution.
Touchscreen computers in vehicles commonly require high brightness LCDs, because of the ambient sunlight coming through the windows. Sunlight readable LCDs are also used in many indoor applications surrounded by windows, such as air traffic control centers, railroad cars, marine vessels, agriculture machinery, and public kiosks.
First, the display screen on a sunlight readable/outdoor readable LCD should be bright enough so that the display is visible under strong sunlight. Second, the display contrast ratio must be maintained at 5 to 1 or higher.
Although a display with less than 500 nits screen brightness and a mere 2 to 1 contrast ratio can be read in outdoor environments, the quality of the display will be extremely poor. At i-Tech, a truly sunlight readable display is typically considered to be an LCD with 1000 nits or greater screen brightness with a contrast ratio greater than 5 to 1. In outdoor environments under the shade, such a display can provide an excellent image quality.
Luminance is a major determinant of perceived picture quality in an LCD. The importance of luminance is enhanced by the fact that the human mind will react more positively to brightly illuminated scenes and objects. Users are typically more drawn to brighter displays that are more pleasing to the eye and easier to read. In indoor environments, a standard active-matrix LCD with a screen luminance around 250 nits looks good. However, a sunlight readable LCD with a screen luminance of 1,000 will look even more beautiful.
A typical AMLCD exhibits a CR between 300 to 700 when measured in a dark room. However, the CR on the same unit measured under ambient illumination is drastically lowered due to surface reflection (glare). For example, a standard 200 nit LCD measured in a dark room has a 300 CR, but will have less than a 2 CR under strong direct sunlight. This is due to the fact that surface glare increases the luminance by over 200 nits both on the white and the black that are produced on the display screen. The result is that the luminance of the white is slightly over 400 nits, and the luminance of the black is over 200 nits. The CR ratio then becomes less than 2 and the picture quality is drastically reduced.
i-Tech sunlight readable LCDs with 1500 nits screen brightness will have a CR over 8 with the same amount of glare under the same strong sunlight, making the picture quality on these units extremely good. For further reading on contrast ratio, please see Tech Note 0101, Page 2, the Display Contrast Ratio.
The viewing angle is the angle at which the image quality of an LCD degrades and becomes unacceptable for the intended application. As the observer physically moves to the sides of the LCD, the images on an LCD degrade in three ways. First, the luminance drops. Second, the contrast ratio usually drops off at large angles. Third, the colors may shift. The definition of the viewing angle of an LCD is not absolute as it will depend on your application.
Most LCD manufacturers define viewing angle as the angles where the CR (contrast ratio)^3 10. For LCDs designed for less demanding applications, the viewing angle is sometimes defined as the angles where the CR^3 5.
For LCDs used in outdoor applications, defining the viewing angle based on CR alone is not adequate. Under very bright ambient light, the display is hardly visible when the screen luminance drops below 200 nits. Therefore, i-Tech defines the viewing angles based on both the CR and the Luminance.
All LCD backlights powered by cold cathode fluorescent lamps (CCFL) require inverters. An inverter is an electronic circuit that transforms a DC voltage to an AC voltage, which drives the CCFLs. i-Tech Technology manufactures inverters for all its products. Additionally, Applied Concepts and ERG also provide inverters for our products as well.
The dimming range or dimming ratio of an inverter specifies its capability of performing backlight luminance adjustment. For inverters used in notebook computers and LCD monitors, the backlight luminance can be adjusted typically over a dimming range of less than 10:1. That is, the luminance is adjusted from 100% down to about 10%.
For very high brightness backlights used in i-Tech Technology sunlight readable LCD modules, the inverters must be able to provide a much wider dimming range. Otherwise, the LCD screen will be too bright during nighttime conditions. Therefore, our inverters provide a typical dimming ratio of 200:1, meaning that the luminance can be adjusted from 100% down to 0.5%.
Any high brightness backlight system will consume a significant amount of power, thereby increasing the LCD temperature. The brighter the backlight, the greater the thermal issue. Additionally, if the LCD is used under sunlight, additional heat will be generated as a result of sunlight exposure. Temperature issues can be handled through proper thermal management design.
We provide TFT LCD with reflective mode of illumination without compromising its transmissive illumination. With the imposed reflective function, the modified LCD can reflect the ambient light passing the LCD cell and utilize the reflected light beams as its illumination. The stronger the ambient light is, the brighter the LCD will appear. As a result, the modified LCD is viewable under all lighting conditions including direct sunlight regardless the LCD"s original brightness.
The market demands for outdoor LCD applications are expanding, such as mobile navigator/video systems, PDA, personal organizer, Tablet PC, notebook computer, and Kiosk display etc. However, a regular transmissive LCD is very difficult to read under strong ambient light. This limits the outdoor applications of a conventional transmissive LCD.
The high bright LCD and the transflective LCD are the solutions generally utilized for outdoor applications. However, both solutions have some shortcomings. Because of the added lamps, high bright LCD creates some undesirable problems, which include high power consumption, excessive heat generation, increased dimensions, electrical circuit alterations, and shortened LCD lifetime. Thus, it is usually troublesome and costly to accommodate a high bright LCD in systems. Though giving good performance under the direct sunlight, the transflective LCD trades of its indoor performances.
Problems noticed in transflective LCD include narrow viewing angle, discoloration, low brightness, and loss of contrast. Moreover, the transflective LCD is currently limited in choice of sizes and resolutions.
On the other hand, a Transflective LCD is readable everywhere including outdoor environments without extra power consumption and excessive heat generation. The indoor viewing qualities are also enhanced. The modified unit fits right back into its original system with no need of any alteration and extra effort. Thus in your choice of size, resolution, and model, a direct sunlight readable LCD is conveniently incorporated into your device.
i-Tech is a premier supplier of optical bonding and performance added passive enhancements for all flat panel . i-Tech Optical Bonding process produces an optical bond between any display cover glass or touch panel, and any size LCD.
In the world of LCD"s, i-Tech takes display enhancement to a new level above all others. Utilizing advanced proprietary optical bonding technology; i-Tech overcomes optical challenges for display product manufacturers at an affordable price. In a wide range of applications, standard liquid crystal appear to "washed out" in high ambient lighting conditions. This wash out is due to excessive reflections and glare caused by bright light.
Commercially available LCDs, especially when protected by a separate cover glass or plastic shield, can not deliver enough brightness to make the display functional in outdoors or in other high ambient light applications. The exclusive Optical Bonding process from i-Tech provides a significant reduction of ambient light reflections at an affordable price, compared to other display enhancement technologies.
Optical Bonding seals either a top cover glass or touch screen directly to the face of the display bezel. Our bonding process eliminates the air-gap between the display and the cover glass, vastly reducing reflective light, which causes visual washout of the display image. Optical Bonding also enhances structural integrity by supporting the LCD assembly with the cover glass. The bond maintains perfect display uniformity while providing shock protection, unlimted humidity protection, and elimination of fogging caused by trapped moisture accumulating in typical air-gap assemblies.
Sunlight viewability of a display depends on the differences between "lumination" and "illumination" of the display. The lumination of the display is its brightness. A display"s brightness, typically referred to as a Nit (Candela per meter/2) is the amount of light energy coming out of the display. Illumination is the amount of ambient light shining onto a display. The readability of a display is dependant on the amount of light that is being reflected off of the display.
Optical Bonding from i-Tech is a solid, transparent bond which optically couples the front cover glass or touch screen directly to the face of the display. This internal bond eliminates reflection from the two internal layers. The outer surface of the window is treated with anti-reflecting coatings which matches the front surface of the glass with the index of refraction of air. This combination reduces the total reflection of the display and front cover glass to less than 2% of the ambient light. A reduction of reflection of this level, all but eliminates reflective loss in most ambient lighting conditions. With reductions of this level, displays with 300-500 nits of brightness will be viewable in daylight or indirect lighting conditions. At 500-800 nits brightness, most displays will be completely sunlight viewable.
Aside from the optical quality, Optical Bonding elminates the air-gap which prevents heat build-up from the "greenhouse" effect and prevents fogging from moisture or contamination from dirt or particles. It also offers shock protection and other damage to the LCD itself.
iTech IP65 Front and Full IP66 Chassis are designed for those applications require IP ( Ingress Protection ) feature, like chemical industry, food industry and medical industry. However, the IP65 Front and Full IP66 chassis might get moisture condensation issue for the applications under direct sunlight.
Another solution, with an anti-glare (AG) coated protection glass, a microscopically rough surface laminated onto the topmost of display can diffuse glare. The chemically etched glass that has a slightly textured finish can reduce reflection by scattering light directed on its surface. It can soften the image of direct light sources visible in the reflection of the viewing area.
Clearing Point - The temperature at which the liquid crystal fluid changes from a nematic into an isotropic state. In practice, a positive image LCD will turn totally black at this temperature and will therefore be unreadable. Because the clearing point is different for every fluid type, ask for design assistance from your supplier if high temperature operation is critical in your application.
Also, for most cases, both TN, HTN and STN utilize the phase known as nematic for display purpose. Within this phase, the liquid crystal has a "rod shape" exists within the solution which has fast response and has excellent electro-optic properties. This phase, however, only exists within a limited temperature range. The higher end of this temperature range is known as clearing point, above which, the liquid crystal lost its birefrigerance properties and cannot bend the light path anymore. Thus the polarizer will then be the only factor which affect incoming and out coming light. When the LCD is cooled down to below its clearing point, the display should be working again. The temperature for the clearing point varies greatly from material to material and you should contact our engineers regarding what you have. Normally a safe margin should be used to avoid clearing point when designing the display.
Light sensor detect the change of illumination outside, then it send the signal to MCU via I�2C interface. MCU will ask inverter to switch the brightness if the outside illumination was change over the default. MCU will transmit PWM signal to the inverter, amd the inverter will change the brightness of panel.
Winmate �light sensor� technology are now available for 8.4�, 10.4�,12.1�, 15�, 17�, and 19� LCD with specific panel option. Please contact with sales for more detail information.
The electronic controls effectively divide the screen into pixel sized sensing cells, using microfine wires which are not visible on a powered display. These wires are connected to a controller board, and an oscillation frequency is established for each wire. Touching the glass causes a change in the frequency of the wires at that particular point, the position of which is calculated and identified by the controller. Unlike other capacitive systems where the operator touches the actual conducting surface of the sensing panel, the active component of the sensor can be embedded up to 25mm from the touch surface ensuring long product life and stability.
Recently there many end customer was mislead believing high brightness (over 2000nits, even up to 5000nits) is the better solution. But there are few concerns that the so called extreme high brightness (3000nits to 5000nits) panel manufacturer don"t tell you:
1. How much power consumption is the extreme high brightness LCD? It is very important because all of our outdoor LCD is in completely sealed enclosures keeping it cool is a very huge Challenge. Not mentioned the hot temperature around 40-50C area.
2. Also, you need to determine how far is viewer distance. Because high brightness (3000-5000nits LCD) might Damage eyesight if the viewer is too closed. LCD is design with high resolution for people to see it very closely, so extreme high brightness doesn"t make sense for outdoor LCD. If they want to put on extreme high brightness LCD on roof top to attract audience which LCD is not even big enough for seeing from far away. Most case customer will use LED which is more reliable and cost effective if it is larger than 82".
4. Viewable under sunlight is not just brightness only, it involve contrast ratio, reflection of the front glass and content graphics contrast such as (red and white). Sunlight readable is combination of all above, not just brightness only.
4. Viewable under sunlight is not just brightness only, it involve contrast ratio, reflection of the front glass and content graphics contrast such as (red and white). Sunlight readable is combination of all above, not just brightness only.
3. All the major branded LG and Samsung LCD manufacturer the most brightness that they do is only 1000-2000nits because we believe this major LCD maker already done a study on what is the most feasible and comfortable LCD brightness for outdoor. That"s why all the high brightness (3000-5000nits) maker is after market vendor without any study about the what is most suitable brightness for different applications, only advertising high brightness is not the solution. If you ask these vendor for outdoor enclosure which they will not provide or guaranteed it will work because they know it is a huge Challenge to cool down the display. Just like you are buying a 800 horse power car, but you still need to design the car frame and cooler to make this engine run safely on the road, which this extreme high brightness won"t help you to design that.
Sun Vision Display panels are100% reflective, meaning they have no backlight whatsoever. This makes them an excellent computer monitor solution for people looking to reduce blue light exposure or other common issues reported by people withcomputer-related vision syndromes. It also makes them an incredible solution for advertising in sunny places, where it can be difficult to view other display technologies - all without racking up hefty energy costs.
Sunlight readable LCD monitors are designed for outdoor industrial display applications. It features a transflective LCD module that improves the display contrast through the high brightness backlight source and illuminance sensor that lets LCD readable display function in over a wide range of illuminance levels. When exposed under the sun, the sunlight-readable display adjusts to the brightness of outdoor conditions and utilizes the light beams to give off illumination. The display reflects against the light passing through the screen and becomes constant with the contrast of the beams. The transflective technology allows the display to become viewable under the brightest luminance regardless of the original brightness of the LCD. Sunlight readable displays can be utilized in all conditions including under direct sunlight and provides better contrast for both outdoor and indoor environments. In the dark, the backlight is turned on to display the best possible image, allowing the display to be useful in both high and low lighting.
Stealth’s sunlight readable LCD monitors are designed to operate in direct sunlight or harsh ambient light conditions. Our rugged LCDs outperform regular commercial products that wash out in direct and or indirect sunlight conditions. Our LCD monitor products have been uniquely designed to meet the challenges of demanding industrial and commercial applications. The all rugged metal enclosed LCDs have been sealed to protect the displays from dust, dirt and sprayed liquids.
Our Sunlight Readable displays are available with various Touch Screen options including resistive and capacitive technologies. Our sunlight readable LCD products have been designed for demanding indoor and outdoor applications and have seen success in, kiosks, digital signs, drilling platforms, ships, outdoor displays, yachts, aircraft and land based transportation to name a few.
There are more and more TFT displays used in outdoor applications, such as automobile display, digital signage and kiosks. High ambient light in outdoor environment often causes wash-out image and renders the screen not readable. Readability & sustainability of TFT display under direct sunlight is becoming vital. Topway Display has been developing sunlight readable LCD display solution for years. The company understands the ins and outs of sunlight readable TFT LCD.
For an LCD to be readable in outdoor environment with very bright ambient light, the LCD screen’s brightness needs to exceed the intensity of light that is reflected from the display surface. To be comfortably viewed by human eyes, the LCD’s brightness needs to exceed its reflected light by a factor of 2.5 at minimum. Naturally, to make an LCD sunlight readable, we can work on two areas, increasing brightness or reducing reflectance.
On a clear day in direct sunlight, the ambient brightness is about 6000 cd/m2. And a typical TFT LCD with touch screen reflects about 14% of ambient light, which is around 840 cd/m2. These days, most LCD displays use LED backlight as light source. It is not too difficult to increase an LCD’s brightness to 800 ~ 1000 Nits, to overpower the bright reflected sunlight. Thus, you have a sunlight readable TFT LCD.
However, this method requires more backlight LEDs and/or higher driving current. The drawbacks are high power consumption, more heat dissipation, increased product size and shorter LED backlight lifespan. Apparently, increasing backlight to make TFT LCD sunlight-readable is not a very good solution.
Transflective TFT LCD is a TFT LCD with both transmissive and reflective characteristics. A partially reflective mirror layer is added between LCD and backlight. This change turns part of the reflected ambient light into LCD’s light source, increasing the TFT display’s brightness. However, transflective TFT LCD is more expensive than transmissive one. At the same time, the partially reflective mirror layer will block some of the backlight, making it not ideal in indoor or low ambient light environment.
The total reflectance on a TFT LCD with touch panel is the sum of reflected light on any interface where two materials meet. As an example, between polarizer and display glass, the difference in index of refractions for the two materials is very small, around 0.1. So the reflected light on this interface is only 0.1%. As Fresnel’s equation points out, we should focus reflection reduction on air interfaces. For air, its index of refraction is 1; for glass, it is 1.5. And that results in a reflectance of 4.5%. Therefore, the three air interfaces contribute majority of TFT LCD’s reflectance, at about 13%.
For food industry application, shattered glass is a serious problem. An LCD screen with external film solves this issue nicely. As for automotive applications, in an accident, broken LCD with top AR film won’t produce sharp edge glass that could harms auto occupant. Nevertheless, a top film always reduces TFT LCD’s surface hardness. And it is susceptible to scratches. On the other hand, AR coating retains LCD’s hardness and touch performance. But it comes with a bigger price tag.
Another quick and easy way to tackle reflectance is to affix a linear polarizer on the top of TFT screen. When ambient light gets to the top polarizer, only half of the light passes through. Which results in reflection light cutting to half. This is a very low cost way to increase TFT LCD’s contrast, such that making it more sunlight readable.
Laminating a circular polarizer in TFT LCD will get rid of a lot of reflectance. That is because when ambient light passes through circular polarizer it gets circularly polarized. And when it is reflected, the polarization direction flips by 180 degrees. So when reflected light comes back to the circular polarizer, nothing goes through to viewer’s eyes.
This method is very effective for an LCD display with resistive touch panel. We know resistive touch LCD has two air gaps: air gap between two ITO layers and air gap between touch panel and LCD display. Reflectance caused by the two air gaps is very high. Applying circular polarizer blocks off most of the reflected light, and makes the LCD display sunlight readable.
The disadvantage of such solution is its cost. Since we need not only a circular polarizer, but also a retarder film on the top of LCD display, making sure light originates from within LCD is not blocked by external circular polarizer.
Add AR films on both interfaces of internal air gap. The add-ons can reduce this area’s reflection from 8.5% to 2%. And since the AR films are not outside facing, they are much cheaper than the one used outside. Keeping the air gap also retains the ease of service, in case either touch panel or LCD display needs to be repaired.
The most effective way is to eliminate air gap totally, by using optical bonding. In plain language, we fill air gap with special optical adhesive, to smooth out the area’s refraction index differences. Such that reflectance caused by internal air gap drops from 8.5% to 0.5%. Optical bonding is expensive but effective way to improve TFT LCD sunlight readability. It enhances durability and resistance to impact. Moreover, no air gap means no moisture condensation and fogging.
There are many ways to make TFT LCDsunlight readable. They all have their own pros and cons. With 20+ years" LCD design and manufacturing experience, Topway knows how to create the best sunlight readable TFT LCD for challenging environments. Leave us a message and let"s start the conversation of creating suitable sunlight readable TFT LCD for your project.
Xenarc Technologies Corp. is one of the first display manufacturers to introduce a 7" LED LCD display with a brightness rating of 1,000NIT. The high brightness of this monitor makes it ideal for outdoor applications under direct sunlight, as well as any other applications where a bright, non-reflective display may be effective. This popular product offers superior readability under sunlight. With their proprietary technology, they are able to increase the brightness rating to 1,000NIT, and the Contrast Ratio to 500:1. Sunlight readability is further enhanced by it"s advanced Anti-Reflective coating. The monitor also comes with a detachable aluminum front bezel, suitable for flush installations, that can easily be put back into place.
LCDs used in outdoor situations have many concerns to deal with in addition to any that they might normally encounter during indoor use. Initially some concerns are weather related such as moisture in the air or extreme temperatures. Another concern that is often not understood or just not known about at all is sunlight damage.
Liquid crystal displays use organic components that are susceptible to UV (<400 nm) and IR (>750 nm). These bandwidths of radiation have an observable impact on the organic components in LCDs. Extended exposure has been known to cause a color shift and a washed out look to images displayed with the LCD.
In any case it is important to protect your display from the elements, especially if it is going to be exposed to harsh environments not intended by the manufacturer. One way to do this would be to utilize a Hot Mirror with a UV blocker. This will significantly reduce the amount of IR radiation between 750 nm and 1200 nm, as well as the UV radiation below 400 nm. If the LCD is going to be used outdoors for extended periods then an extended hot mirror may be necessary, which extends the bandwidth protection out to 1600 nm and will help reduce some of the longer wavelength IR damage.
Another concern with liquid crystal displays are their susceptibility to overheating due to excess IR radiation. The LCD is intended to operate within a certain range of temperatures according to the manufacturer’s instructions and outdoor use can lead to higher than normal temperatures. The display being exposed to excessive heat can cause the crystal to become isotropic and fail to perform properly. A hot mirror can help alleviate these concerns as well by reducing the amount of infrared radiation that heats the display.
The Xenarc 1569 series of15.6” touchscreen displaysis perhaps the most versatile and all-encompassing product in Xenarc Technologies’ line up of products. This16:9 1000 NIT High Bright Touchscreen isIP67andIK08rated and includes an optically bonded capacitive touchscreen, making it ideal for any harsh industrial environment. The 15 inch touch panel is optically bonded to the LCD panel, eliminating the air gap between the two, increasing clarity, contrast, and durability. Further, because the 15.6" touchscreen display unit iswater tightandair tight, ambienthumidity will notaffect the clarity or viewability because of the advanced optical bonding. The 1569GNH 15 inch touchscreen monitor outperforms allautomotive grade panelswith a wider operating temperature range of-30C ~ 85C (-22F ~ 185F)and uses an IPS panel (In-Plane-Switching), which provides a wider viewing angle, consistent and accurate colors from all viewing angles, clearer images, and stable response times. Ahigh contrast ratio of 1000:1provides crisper images and vivid colors, even in direct sunlight.
The versatility of the 1569 series extends beyond its usability in many different environments. The 1569GNH can video interface through our proprietary 26 pin cable (HDMI, VGA, AV Inputs) as well as HDMI direct into the monitor. The 15.6" touchscreen display monitor comes with anHDMI output thatallows you to chain up a few 1569 series 15.6" touchscreen monitors oroutput to other HDMI monitors. With the included waterproof cables, the 1569GNH is IP67 on all sides and angles. The casing of the 1569GNH is designed to be used as a stand-alone monitor as well as a panel mount monitor. VESA standard mounting holes on the back further provide users with numerous mounting options. TheIK08 rating makes the 1569GNH vandal resistant and shock resistant.