how to see lcd screen in sunlight supplier
A sunlight-readable display is necessary for most outdoor use, whether it is a rugged tablet, a kiosk, or an agriculture application. Sunlight readability is defined quite differently by different display manufacturers. Some say that a luminance of 1000 nits is the bottom floor for true sunlight readability, but often manufacturers will say displays are sunlight readable with brightnesses of half that. And, sunlight viewability is more complicated than a simple luminance measurement. Contrast ratio is also very important. Contrast ratio is independent of brightness, and the contrast ratio itself can change, depending on background light levels. Therefore, displays are best compared side by side in bright noonday sun. There are four methods to make sunlight readable display, and one trick:
By applying more backlights, display brightness can be increased to 1000 nits or more. The added light overpowers ambient light and make the screen viewable. This can be thought of as a brute-force method. This is our 1000 nits rugged tablet.
However, adding more backlights always means greater power consumption. On a 7” kiosk display, it can consume ten watts or more. Nearly all of that power goes to heat, requiring much more cooling. And since such displays are made for the industrial market in small quantities, costs are much higher than ordinary LCD displays.
Transflective (transmissive-reflective) displays are hybrids. Two different methods for display are used. Under bright illumination the display acts mainly as a reflective display, with the contrast being constant with illuminance. In dim light, the backlight provides needed illumination. With a special semi-reflective filter in the back of the display stack , it can reflect the sunshine outdoor, while the back light can also offer the light penetrating the semi reflective file in the back of the screen.
Transflective technology has been widely applied by many rugged tablet manufacturers, like Motion Computing, Panasonic, Getac, and Winmate. Transflective technology is much more expensive than ordinary rugged tablet displays.
Optical bonding injects a clear, optical-grade resin into the gap between the LCD panel and the protective outer glass, bonding them together. This fills the air gap between the two, eliminating two reflective surfaces. An anti-reflective coating is then applied to the outside of the protective glass, minimizing surface reflections as well.
Glare is caused by a reflection of light on the mirror-smooth surface of the monitor. An anti-glare film is a thin sheet of transparent plastic that is overlaid on a monitor or screen to make reflections more diffuse. Not all anti-glare films are created equal. Some are worthless, while better ones can make a real difference. The best and most expensive films come from Japan.
Finally, there is one trick that anyone can use to make any display much more viewable in sunshine – wear a hat with a broad brim, and wear a dark-colored shirt. This minimizes eyestrain from direct sun, and reduces stray reflections on the display. It sounds silly, but it makes a real difference.
Effects of direct sun-light exposure to Touchscreen equipped Liquid Crystal Display monitors and mitigation techniquesIntroductionLiquid crystal, at room temperature, is neither a liquid nor a solid. This state allows liquid crystal to be usable as a light controlling device – i.e.: Liquid Crystal Display (LCD). However, liquid crystal can be adversely affected by temperature changes causing undesirable results. Low temperature environments can cause the crystal to transition more to a solid thus causing the crystal to be less responsive to changes needed to properly control light. In a LCD this can be observed as slow transition time from frame to frame (choppy video or memory of previous image). Higher temperature environments cause the liquid crystal to transition more to a liquid state, again causing the crystal to not perform correctly when controlling light. This effect can be seen in an LCD as a lowering of contrast ratio (darkening) or in extreme heat conditions melting the crystal resulting in a completely dark LCD image. Direct sun-light exposure typically does not cause LCD to internally heat enough to reach the liquid crystal’s melting point. However, touch monitors have a glass overlay and air barrier on top of the LCD. This can cause a greenhouse effect causing the air temperature between the touch sensor and LCD to become much hotter than the ambient temperature.Preventive measures
Orientation: The easiest way to prevent thermal heating by the sun is of course to not expose the LCD to direct sunlight. In many cases simply orienting the face of the LCD monitor in an East/West position will prevent the greenhouse effect and darkening of the LCD.
Covering or awning: If orientation cannot be controlled and the design allows for it, a simple shade can be employed to block direct sun light. The shade can be a protective awning overhead, or a cover that lies over the screen prompting the user to open or remove the covering to use the device.
Touch Technology choices: Touch sensor design varies based on the given technology. Technologies such as APR and SAW are based on glass only technologies. Resistive and Capacitive technologies have coatings which block some light transmission in both directions. In theory, touch sensors with coatings would slow the greenhouse effect by blocking a percentage of entering light thus slowing the LCD darkening. Touch sensors such as Infra-Red and Optical have no boundaries on the substrates; thus films, coatings or substraight material itself can be adjusted to block additional light.
Films and Coatings: Films designed to block light can be applied to some touchscreen technologies to slow the greenhouse effect. APR, resistive, capacitive, Infra-Red, and Optical all would be candidates for addition of films. The below experiment shows the results of three APR screens with various films and no film applied.
TestingTesting was performed on three Elo ESY15B1-APR products, outdoors in direct sunlight for 4-hours. A white background was displayed and a burn-in was test running to load the processor.
The Elo product with *Nushield, NU204GA Anti-Glare film applied, looked very dim before testing and was difficult to read after 4-hours but the pixels did not melt.
Note: The product with NU405RA film also appeared clearer in normal conditions than the one without a film applied, however the touchscreen was a little more difficult to activate with the shield verses without the shield.
Note: The beginning luminance readings of the product with NU405RA film applied were higher than the no film control. This may explain the appearance of a brighter screen with film applied.
*Elo Touch Solutions is not affiliated with Nushield or any other film providers. Elo Touch Solutions offers no warranty, implied or expressed, as to the products or techniques described in this white paper. Information was collected and assembled for edification purposes only, and individual results may vary.000001369
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When display devices are brought outside, oftentimes they face the brightness of sunlight or any other form of high ambient light sources reflecting off of and overwhelming the LED backlight’s image.
With the growth of the LCD panel industry as a whole, it has become more important than ever to prevent the sun’s wash out of displays used outdoors, such as automobile displays, digital signage, and public kiosks. Hence, the sunlight readable display was invented.
One solution would be to increase the luminance of the TFT LCD monitor’s LED backlight to overpower the bright sunlight and eliminate glare. On average, TFT LCD screens have a brightness of about 250 to 450 Nits, but when this is increased to about 800 to 1000 (1000 is the most common) Nits, the device becomes a high bright LCDand a sunlight readable display.
Doing this is an affordable option for enhancement of image quality in the outdoors, including features like contrast ratio and viewing angle, in a common use setting like with phones.
Since many of today’s TFT LCD display devices have shifted to touchscreens, the touch panels on the surface of LCD screens already block a small percentage of backlighting, decreasing the surface brightness and making it so that the sunlight can even more easily wash out the display. Resistive touch panels use two transparent layers above the glass substrate, but the transparent layers can still block up to 5% of the light.
In order to optimize the high brightness of the backlight, a different type of touchscreen can be used: the capacitive touchscreen. Though it is more expensive than the resistive touch screen, this technology is more ideal for sunlight readable displays than the resistive due to its usage of a thinner film or even in-cell technologies rather than two layers above the glass of the display, and therefore, light can pass more efficiently.
However, with this method comes a list of potential problems. Firstly, high brightness displays result in much greater power consumption and shorter battery life. In order to shed more light, more power will be needed which can also consequently result in device overheating which can also shorten battery life. If the backlight’s power is increased, the LED’s half-life may also be reduced.
While in bright exterior light settings, these devices reduce eye strain as the user attempts to view the image on screen, the brightness of the display itself can also cause eye strain, seen as the brightness may overwhelm your eyes. Many devices allow the user to adjust brightness, so this concern is oftentimes not too severe.
A recent technology falling into the sunlight readable display category is the transflective TFT LCD, coming from a combination of the word transmissive and reflective. By using a transflective polarizer, a significant percentage of sunlight is reflected away from the screen to aid in the reduction of wash out. This optical layer is known as the transflector.
In transflective TFT LCDs, sunlight can reflect off the display but can also pass through the TFT cell layer and be reflected back out off a somewhat transparent rear reflector in front of the backlight, illuminating the display without as much demand and power usage from the transmissive nature of the backlight. This addresses both the issues of wash out and the disadvantages of high brightness TFT LCDs in high ambient light environments. Because of its transmissive and reflective modes, this type of device is very useful for devices that will be used outdoors but also indoors.
While it does greatly reduce power consumption, transflective LCDs are much more expensive than high brightness LCDs. In recent years, the cost has decreased, but transflective LCDs continue to be more costly.
In addition to adjustments to the internal mechanics of LCDs, it is possible to make devices more sunlight-readable using surface treatments. The most common are anti-reflective (A/R) films/coatings and anti-glare processing.
Anti-reflective focuses on depositing multiple transparent thin film layers. With the thicknesses, structures, and properties of each individual layer composing the film, reflecting light wavelengths are changed, and thus less light is reflected.
When anti-glare is used, reflected light is fragmented. Using a rough surface as opposed to a smooth one, anti-glare treatments can reduce the reflection’s disruption of the actual image of the display.
Often paired with other methods of creating sunlight readable displays is optical bonding. By gluing the glass of a display to the TFT LCD cells beneath it, optical bonding eliminates the air gap that traditional LCD displays have in them using an optical grade adhesive.
This adhesive reduces the amount of reflection between the glass and LCD cell as well as the reflection of external ambient light. Doing this helps provide a clearer image with an increased contrast ratio, or the difference in the light intensity of the brightest white pixel color and darkest black pixel color.
With this contrast ratio improvement, optical bonding addresses the root issue with unreadable outdoor displays: the contrast. Though an increase in brightness can improve contrast, by fixing the contrast itself, LCD display images in outdoor environments will not be as washed out and will require less power consumption.
Besides the visual display advantages that optical bonding provides, this adhesive improves the display in many other ways. The first being durability, optical bonding eliminates the air gap within the device and replaces it with a hardened adhesive that can act as a shock absorber.
Touch screens with optical bonding gain, accuracy in where the point of contact is between the touch and screen. What is known as parallax, the refraction angle of light, can make it seem that the point of contact and the actual point on the display are different. When the adhesive is used, this refraction is minimized, if not reduced.
The optical bonding adhesive’s elimination of the air gap also protects the LCD from moisture/fogging and dust, as there is no space for impurities to penetrate and remain under the glass layer. This especially helps with maintaining the state of LCDs in transport, storage, and humid environments.
Compiling the various methods of improving LCD screens for sunlight readability, these devices can be optimized in high ambient light settings. An anti-glare coating is applied to the surface of the glass and anti-reflective coatings are applied to both the front and back. The transflector is also used in front of the backlight. These features can result in 1000 Nit or more display lighting, without the excessive power consumption and heat production through a high brightness backlight, consequently allowing for a longer lasting and better performing LCD
Unfortunately, the process of building a reflector inside TFT LCD is complicated and transflective TFT LCD is normally several times higher cost compared with normal transmissive TFT LCD.
To further improve and enhance the qualities of the LCD, LED and cold cathode fluorescent lamp (CCFL) backlights are used. Both these create bright displays, but the LED specifically can do so without as much power consumption and heat generation as compared to the CCFL option. Optical bonding is also applied in order to improve display contrast, leading to a more efficient and better quality sunlight readable display.
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.
Backlit LCDs provide excellent visibility indoors, but require high-brightness backlights to produce enough brightness for for direct sunlight readability - 1000 nits or more, to be exact. All that brightness requires a lot of power to operate, making traditional high-brightness LCD signage costly in multiple ways.
Sun Vision Display panels actually turn sunlight into an asset through their reflective LCD technology.They"re the perfect solution for sunny locations. In fact, as sunlight or ambient light shining on the display increases, so does the brightness of the Sun Vision Display panel"s image - all while consuming almost no power (less than 6 watts). No need to shield the display from the sun!
degrees. So, in this range we are safe, we can go very low with the temperature, and it will not become solid, and we can go very high with the temperature up to 110 degrees and it will not become isotropic.
Maybe you have even seen some displays that were used outdoors and sometimes they become black. We call that the blackening effect. If they become black, that means the crystals become isotropic. You can sometimes see that the part of the display is black or sometimes the whole display becomes black, depending on the temperature. The good thing is that it is not damaging the display, so once the temperature drops it goes back to the nematic phase and the display is working again, but in a high temperature you cannot see anything on the display, it is not working.
On the picture above, we have an example from a data sheet of a display with high temperatures. As we said it’s a liquid crystal from -40 to +110 degrees, and this is the latest technology. But you need to be careful! This is only about the surface of a display, the TFT glass itself. If we have the sunlight going to the display it can increase the temperature of the whole display as a module.
For the whole display module, the operating temperature range can be as low as 0 to +50 degrees or -20 to 70 degrees. We can have two operating temperatures, that means if we use the display outdoors, we are safe from the sunlight, the surface of the display can go very high, but we need to control the ambient temperature inside the display housing to not go too high. +50 or +70 will be maximum, usually we need fans to remove the heat from inside. Typically, in our case we have a computer inside and we have more devices that cannot work at high temperatures like +100 degrees, so we control the temperature anyway. So, the temperature cannot be too high inside and for sure cannot be that high as a liquid crystal itself can withstand, which is +110 degrees.
And that will be all in this article about contrast, brightness, and temperatures. Just one more thing: if you are planning on buying a laptop today, you can find brightness in the specification. Look at this number because this will determine how good your laptop will be outdoors. There are laptops on the market today that will have 1000 candelas or even more. If you are looking for a new device my recommendation also goes for mobile phones. Low brightness mobile phones can have 300, maybe 500 candelas, but nowadays the standard will be around 1000 candelas, but there are phones on the market that already have 1500 or even 1800 candelas. That means if you are in the sunlight you will still be able to see the image clearly. Of course, the battery will be drained faster, but sometimes it is not so important, maybe you just want to check something quickly, to read something and you want to have a clear image just be aware that this number is pretty important when you buy new devices!
It can be difficult to read an LCD display under intense sunlight, especially when it does not have adequate sunlight-readability features. People working on this equipment outdoors would have to work hard to make sure that the screen is readable.
Fortunately, technological advancements are underway to resolve technical issues and other problems faced by individuals who regularly use outdoor LCDs. In the meantime, if you are looking for technical fixes that address the lack of sunlight readability in LCD displays or screen panels, keep these solutions in mind.
A simple solution to improve readability in bright outdoor locations is to turn up the brightness to the maximum level. This will help offset the glare produced by the sun’s rays.
Besides cranking up the brightness, you may want to go for optical bonding as your next technical solution. The goal of optical bonding is to shield the external layer of the LCD display from damage. This damage is usually caused by the sun, water, dust, dirt, and other debris. This process consists of laminating the surface layer of the glass to combine with the elements of the LCD inside the display. Afterwards, a bonding agent, such as silicone or urethane, fills the gap between the LCD layer and the glass. This stops potentially dangerous elements from piercing the surface.
Other than safeguarding the internal mechanisms of the LCD device, optical bonding provides better visual clarity for the user by minimizing the amount of glares, reflections, and shadowing caused by the sun.
Apart from making the screen unreadable, sunlight can also cause the temperature of the device to rise quickly. When a device overheats, it causes the solid LCD crystals to melt. This results in the screen to turn black and become unusable until the crystals cool down and harden again. Thus, it is crucial to install a properly designed ventilation structure in these outdoor devices.
Besides ventilation, mounting an outdoor LCD displays requires protection against the sun. Sunlight contains ultraviolet (UV) rays. Prolonged and excessive exposure to these rays can damage the LCD device. It can affect the display to the extent where it will decrease the readability, which is why it is vital to apply a high-quality protective film. Doing so preserves the lifetime and sustainability of the LCD device.
On top of UV protection, you should also protect an LCD display with an infrared protective film. Infrared light beams give off heat. An LCD display not adequately shielded with infrared could cause the device to overheat and cause damage to the display. Having a working anti-infrared solution will protect the device and improve sunlight readability.
If you are seeking LCD display with sunlight readable technology, contact Microtips Technology. Some of our OLED display modules, such as the White 20×4 OLED display, have sunlight readable enhancements, such as polarizers and special films. Rest assured that our products do an amazing job in displaying all kinds of pictures, text, and full motion video.
The dogxl240 has a 8MHz SPI interface. There are 240*128=30720 pixel available, so as a max refresh rate there could be 260 frames per second (FPS). Of course there is some overhead and some other timing aspects have to be considered, so it might be lesser than this.
I have just tested U8g2 Software emulated SPI (which is known to be very slow) on an Arduino Due in U8g2 full frame mode and received about 2 FPS. I assume with hardware SPI (also supported by U8g2) it will be around 20-30 FPS.
The other that you suggest, looks like it"s not reflective (at least because it seems to have a backlight) and maybe is not readable with direct sunlight:
Yes, it is not reflective, but still it is readable (but of course not as good as reflective). I mean, there is always a tradeoff. It aliexpress display is cheaper and has a backlight (so it is readable in the dark also).
For example I just did the FPS tests with a transflective version of the DOGXL240 in my lab with not so bright artificial light. But I also did not turn on the backlight of the DOGXL240: It is readable, but definitly not as good as a reflective version under the same light conditions.
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 the scientific term for hotopic Brightness?which specifies the visual brightness of an object. In layman"s terminology, it is commonly referred to as brightness? Luminance is specified in candelas per square meter (Cd/m2) or nits. In the US, the British unit Foot-lamberts (fL) is also frequently used. To convert from fL to nits, multiply the number in fL by 3.426 (i.e. 1 fL = 3.426 nits).
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.
Contrast ratio (CR) is the ratio of luminance between the brightest �white� and the darkest �black� that can be produced on a display. CR is another major determinant of perceived picture quality. If a picture has high CR, you will judge it to be sharper and more crisp than a picture with lower CR. For example, a typical newspaper picture has a CR of about 5 to 7, whereas a high quality magazine picture has a CR that is greater than 15. Therefore, the magazine picture will look better even if the resolution is the same as that of the newspaper picture.
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%.
Dimming capabilities are beneficial because lowering the backlight luminance will result in a lengthening of the backlight life. It also lowers the power consumption and the related thermal management issues.
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.
Light travels through a variety of transparent materials; such as air, glass, plastic, and even water. These material"s abilty to transmit light is measured by their "indices of refraction". As light transfers from one material to another, such as air to glass, the differences the index of refraction will cause reflection. In the case of an air-to-glass interface, the reflection will be slightly less than 5% of the ambient light. All surfaces that have an index mismatch will reflect and the reflection is cumulative. In the case of a standard glass or plastic window, there are three surfaces with an index mismatch which will create a total relfection of nearly 15% of the ambient light. If the total reflection (in nits) is close to the displays brightness, the contrast of the display will be reduced to the point where the display"s readabilty is reduced to unacceptable levels.
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.
We provide two different choices of optical enhancement solutions that include anti-reflective coated and/or anti-glare protection glass. These technologies can be widely used in outdoor and indoor environment by enhancing optical performance of displays.
The anti-reflective coatings on the protection glass have excellent performance in tough ambient light conditions. With the normal glass, the strong reflection of the ambient light diminishes visibility and causes problems for viewer. Our special anti-reflective coated protection glass can increase contrast by enhancing light transmission rate over 95% (light reflectance rate less than 5%) and can effectively diminish the mirror images. The multi-layer vapor deposition coating either on one side or two sides of glass is designed to minimize reflectance and maximize transmittance.
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.
Isotropic Stage The point where the fluid heats or cools to where it is no longer in the twisted nematic state. Since the molecules can no longer twist light, all incoming light is absorbed.
The lighter sensor measures the outside brightness according to different environments and sends the information to display. Display will adjust the brightness automatically.
With lighter condition (Outdoor/Sun-light) the brightness will increase; in the opposite condition, the brightness will be decreased to fit darker environment.
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.
Each step has its own illuminate range according different environment illumination. This technology makes the use of visual application more friendly and intelligently.
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.
TouchScreen Solutions is a specialist manufacturer of touchscreens, optical filters to enhance the performance of electronic displays, and transparent composites.
By utilising TouchScreen Solutions�s traditional lamination expertise, touchscreens are designed to provide the highest levels of light transmission, excellent readability and unsurpassed protection against a wide range of physical threats. The touchsacreens are accurate, highly dependable and have a rapid response time
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.
The touchscreen can be supplied with the options of anti�glare or anti-reflection coatings, thermal toughening or chemical strengthening and privacy or contrast enhancement filters. The front glass of the touchscreen acts as a dielectric and enhances the capacitance of the touchscreen.
The driver software allows the touchscreen to interface with the host computer�s operating system by emulating the behaviour of a computer �mouse� and translates taps on the touchscreen surface into mouse clicks.
Touchscreen is proven to meet today�s demanding requirements for ATM�s, web phones, ticket machines, medical displays, industrial displays, pay-at-the-pump gas machines, and interactive kiosk systems. The touchscreen is durable and dependable, its construction protects against damage caused by moisture, heat and even vandalism.
The touchscreen comprises a laminated glass sensor, which encompasses the sensing medium, and the control card which connects to the communications port of the computer.
Female D9 serial connector on a 3 metre long, 3 wire, lead. Maximum length of lead - 10 metres. Power supply components in connection -2 diodes, 1 resistor and 1 capacitor .
Simple calibration and set-up with Windows 98, NT, 2000, XP and Linux. Mouse emulation with Select on Touch, Select on Dwell, Select on Release and Drag and Drop.
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".
3. High chance rejection from city sign official. Many LED billboard brightness can goes up to 5000-7000nits, but the local government agency will not approve this brightness, because it is traffic distraction for driver or other people. So, it doesn"t make sense to spend a fortune on extreme high brightness but need to dim it down back to 1000-1500nits.
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.
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 screens 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 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.
Tru-Vu Monitors Inc., a supplier of industrial-grade LCD monitors and touchscreens, has released a 21.5-inch waterproof sunlight readable LCD display designed to operate in direct, bright sunlight or in other high ambient light conditions, according to a press release. Features of the SRMW-21.5Z monitors include:1920 by 1080 full HD resolution and 1,000 nits of brightness, four times brighter than a standard monitor or TV.
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.
LCD displays are classed as transmissive displays, meaning they do not produce their own light source but rely on another light source to make them visible.
Flat panel LCD displays are built from multiple layers that work together to produce the final on-screen image. At the back of the panel the first layer is the backlight. This is the primary light source for the screen which ultimately makes the image visible. Previously a diffused panel of cold cathode tubes (fluorescent lights) was used for the light source but modern LED technology is more energy efficient and long lasting.
Most modern LCD monitors now use LED’s for their backlight, either around the edge of the screen or as a complete matrix which covers the entire screen area. A full backlight matrix provides many advantages over the edge-lit system. It usually results in a brighter and more even image but it also allows for the controlled local dimming of areas of the screen to help increase contrast and improve black levels. A full matrix backlight costs more than the edge-lit version and also increases the overall size and power consumption of the unit with the trade-off being overall better image quality.
Some screens take advantage of a transflective layer. This layer reflects incoming light back out of the panel increasing the light output of the screen in bright conditions. This technology is most commonly found in smaller screens like automotive screens and portable devices as it is a great way to reduce energy consumption.
However the light behind the screen is produced the next layer in the panel is a polarising filter which aligns the light waves into a single direction. The polarised light now enters the actual Liquid Crystal layer. This layer determines whether the light passes through or not. The panel is made up of individual cells, three cells side-by-side represents a single screen pixel. So a Full HD resolution screen, 1920 x 1080 pixels, would require 6,220,800 cells to produce a full colour image.
Each of the three cells in a pixel represents a primary colour – Red, Green and Blue. The Colour Filter layer consists of rows made from these three colours aligned to the cells below. As all other colours in the visible light spectrum are made from these three primary colours by mixing the intensity of each cell the LCD can produce any colour required. So if you wanted to produce the colour Red on screen the Blue and Green cells would turn on, blocking the passage of light and leaving only the Red cell to light up. As the cells are so tightly packed if all three are turned off to allow the light to pass through the human eye perceives the combination of the primary colours as white light.
Anyone who has taken a laptop outside on a sunny day will know that standard LCD screens do not hold up well in very bright conditions. The main reason for this is that the backlight in the screen is having to compete with the incoming sunlight and inevitably the sun is brighter.
Daylight visible screens have extra bright backlights to help push the image through in high ambient light conditions. The standard measurement of brightness for LCD monitors is cd/m2 (candela per square metre) or Nit (believed to be derived from the Latin word nitere, to shine). 1 nit = 1 cd/m2 so the terminology is interchangeable. Candela is the standard unit of luminance and for screens it is measured over a standard area of 1 metre squared.
LCD screens for desktop monitors typically rate at anywhere between 250cd/m2 and 450cd/m2. Large format Public Display monitors typically range from 350cd/m22 up to 700cd/m2. Some manufacturers claim 700cd/m2 to be a high brightness screen, which technically it is, however it cannot really be classed as daylight viewable. Generally anything above 1000cd/m2 can be considered a daylight screen but as with most technology bigger is better. Screens rated at 2,500cd/m2 and above produce excellent results in very bright conditions. Currently the brightest LCD displays available are rated at 5,000cd/m2.
However having a bright backlight on its own does not make for a good looking LCD screen. Just turning up the light source behind the screen can lead to washed out colours, poor contrast and a generally disappointing image. To produce great looking and vivid images your screen needs high levels of contrast and accurate colour reproduction. A full matrix LED backlight allows for high brightness but combined with local dimming it can create high contrast images with deep black levels. By calibrating the colour of the screen you can help produce more natural looking colours. Many LCD screens are prone to a bluish tint leading to colours looking cool. Ensuring your screen is properly calibrated helps maintain a true colour reproduction leaving skin tones looking natural and whites as pure white.
The other issue affecting LCD panels that are used in sunlight is their susceptibility to damage from the heat of the sun. When the Liquid Crystal layer is heated the crystal warps resulting in dark patches forming on the screen. If removed from the heat these patches will usually cool and return to normal but repeated exposure will eventually lead to permanent damage. Professional high brightness displays use LCD panels that are rated for operation under extreme temperatures and do not warp or blacken.
A good quality high brightness screen will look great in all conditions. The added brightness makes your content shine whether it is installed inside or out. As with most visual things you have to see the difference these screens produce for yourself. Photos of these screens just do not capture the true quality of the image when compared to standard screens.
Clients outside of the U.S.A. or Canada. Or, simply use our easy Product Information form (link below) to let us know more about your application and project needs.
NAVPIXEL NPD2425, the high-performance, rugged touch monitor, is specially engineered to survive from the most demanding working environment. Housed in a milled billet aluminum case, the slim-profile N