lcd screen leaking fluid quotation

Just recently I"ve noticed a very sticky liquid leaking out of one corner of the screen. There are now bright and dark patches on the screen near where it"s leaking. As well as round the screen the sticky stuff gets onto the base of the laptop where I rest my hands to type. lt"s really hard to clean off and I"m worried it may be toxic.

There has been no physical damage to the laptop at all - it just started leaking. Is this a common fault or is it a sign of a defect in the design and manufacture?

On a serious note, I"ve never heard of them just leaking. It makes me wonder how they were stored? Somewhere hot, perhaps, rather than cool and dry, like the manuals always suggest?

If it makes you feel any better, old cameras have that problem too, only not with LCDs. Foam light seals dry up and turn to powder, or turn into gum. Lubricants dry up or migrate away from where they belong. Leather dries out. Plastics age, fade in color and get brittle. The only things immune to the ravages of Father Time are glass and stainless steel.

There are very obvious massive black spots on the surface of the long bar LCD screen, or there are uneven patches of light and dark and cracks at the same time. The liquid crystal display is squeezed or impacted by the external force, resulting in the liquid leakage phenomenon caused by the rupture of the liquid crystal screen. The external force is not too large, although the liquid crystal screen leakage, but there is no crack on the surface, this fault phenomenon is not easy to find, especially in the case of LCD power is not bright. After the liquid crystal display ruptures the leak, the image can still be displayed.

Strip liquid crystal screen leakage is physically damaged, and the liquid crystal screen is cut and manufactured as a whole, once the leakage will slowly expand, or even can not display normally, which is irreparable unless the entire screen is replaced. But in terms of the cost of making liquid crystal displays, the screen accounts for 2/3, so it"s not cost-effective to replace the screen, so it"s better to buy a new monitor.

The control and drive circuit in the bar display module is a low-voltage, micro-power CMOS circuit, which is easy to be breakdown by static electricity. Electrostatic breakdown is a kind of irreparable damage, which must be paid attention to and should not be careless. Therefore, the display screen in the operation, assembly and use should be careful, to strictly prevent static electricity.

A maintenance film is affixed to the surface of the installed bar display screen to prevent defilement of the appearance during assembly, so it should not be removed before the whole machine is assembled, so as not to stain or damage the appearance surface.

The above is how to maintain the whole content of the bar LCD screens, I hope that we can learn the method of maintenance, so as to prolong the life of the LCD screens. If you want to purchase bar lcd screens, please contact us by email to

Have you ever wondered what happens if your LED TV gets wet? If you have a flat screen TV that you want to move outside to the garden, patio or pool area, be warned…

You don’t have to go to the trouble and expense of buying a specialised outdoor TV to get a perfect outdoor entertainment area. SealTV have fully weatherproof, tamperproof and fireproof enclosures for a fraction of the expense of a specialised TV, plus, you can use almost any flat screen TV you already own.

If you ignore our warnings or if you accidently get your TV wet then you do need to worry. Worry a lot. It doesn’t need to be a lot of moisture either, dew or a splash from a garden hose or half a glass of beer is enough to do irreparable damage to your screen.

Water is another fantastic (less stable) conductor of electricity. The perfect combination of water, copper and electricity will create a corrosive mix known as electrolysis that will burn out the copper and kill communication systems between your screen and your hardwiring. It is fatal. Your TV will not be able to be repaired.

Get on this early and your TV can be returned to you, with just the repair fees for your troubles. Try to use a wet flat screen TV and you’ll be sending it to the recycling centre.

I’d love to share this video of a TV service tech doing an open operation on a ‘watered LCD TV.’ He walks us through the dissection and provides step-by-step evidence of the damage. When you see how small these copper teeth are you’ll understand how even a small amount of moisture can do rapid damage. It’s also a great demonstration that electricity, water and circuitry really aren’t a great match.

See the dissection and analysis of the 40-inch Sony Bravia LED LCD TV in this YouTube video by norcal715.Most repair centres would simply tell you to bin the TV, in the video there are suggestions for how it might be possible to replace the LCD screen panel or strip the copper teeth and try overlaying with a conductive material. The work sounds tedious and expensive and you would never have the same confidence in a patch job system. As for locating a new screen…you’d have to search eBay and similar sites to find a suitable, high-quality matching screen and components as parts and then locate a tech who is willing to reassemble it for you.

Tesla has always made a lot of the quality and dynamism of their media control unit, or MCU, otherwise known as the large and dominating touchscreen that so fills Tesla cars’ interiors. The “small” units are 15 inches in size, and the larger ones 17 inches. Tesla moved all the main functions of their vehicles into these screens, thus heralding a new revolution of digital automotive wizardry.

These negative feelings were later amplified by the emergence of serious problems in the screens, some of which eventually even prompted serious recalls.

One of the most frightening and best-known issues emerged in 2012-2018 Model S and Model X cars, which use the larger 17-inch screens, where toxic fluid was emerging into the screens, creating bubbles, and then even leaking out of the screen:

There was even a petition started on Change.org where disgruntled owners came together to reject Tesla being able to charge anyone whose car fell outside of the warranty period. Before the formal recall (for an eMMC issue, not for leaking screens), drivers were being quoted anywhere from $1400-2000 for screen replacement.

One thing many people have asked upon seeing the Tesla screens for the first time is how it is and why it is that only Tesla has such large and impressive screens in its cars where other OEMs are still messing around with standard 7-inch displays and “upgrading” to “large” 10.2-inch displays, which is about the industry average.

Some explain away the difference by simply pointing out that most EVs and other cars with touchscreens are favoring the addition of digital instrument displays, such as the Audi Virtual Cockpit, which supplants the need for a large central touchscreen.

So what’s really behind Tesla’s unique screens? The truth is that Elon Musk and Tesla didn’t even turn to an automotive manufacturer to get their screens, they instead turned to laptop producers and computer divisions of larger corporations. Musk’s general idea was that laptop screens were pretty sturdy nowadays, so what did they have to fear from getting a larger computer screen to make Tesla cars really unique?

This story is mentioned in the biography of Elon Musk written by Ashlee Vance. Musk’s team points out to him that “there’s nothing like that in the automotive supply chain,” to which Musk replies, “I know. That’s because it’s never been put in a f**king car before.” He also explains to his team why he believes a more regular computer screen would be sufficient: “The laptops are pretty robust. You can drop them and leave them out in the sun, and they still have to work.”

This was Musk’s summation, but was he right? The fact is that none of the screens he looked at did meet the particular automotive standards that would normally be favored by OEMs, in particular when it came to withstanding the pretty unique heat fluctuations that many vehicles experienced when in use.

Tesla finally ended up with a screen from Taiwanese manufacturer InnoLux, the G181J1-LE1, as its choice for the 17-inch display. This decision would eventually prove quite a fateful one.

The screen itself is an excellent product, and is tested for industrial applications, which makes the rigor of testing considerably higher than you’d expect of any laptop computer. This is partly what informed Tesla’s choice, since they — or at least, Musk — thought that a laptop-style screen would be sufficient, and would allow for a much greater size.

All the testing done at InnoLux and then subsequently by Tesla seemed to show that this screen would indeed stand up to anything put before it, and Tesla could go ahead with their monster MCU that would set them apart.

The first problem to emerge was the above-mentioned bubbling issue. The cause? Almost certainly it was to do with heat. The huge heat fluctuations that the cars experienced, especially in hot climates like southern California, saw bubbles forming at the edges of the displays, and sooner or later starting to leak out a toxic, adhesive fluid into the expensive Model S or Model X interior.

Tesla first claimed to fix this problem with their “Cabin Overheat Protection” feature, but even that was considered a non-fix in reality because not only did the problem continue, but others started to emerge, too such as the now infamous yellow banding around the edge of the screen, caused by an adhesive used in production that also couldn’t stand up to the temperature extremes.

The next solution to the bubbling and other problems was to offer new screens, but this presented new difficulties. They’d only be replaced under warranty if the warranty was still valid.

This was a step short of a recall, even though Tesla was encouraging and promoting new screens being available to fix the problem. Those with active or extended warranties could get their screens replaced, while others faced huge bills.

Finally, problems with the screens came to a head when regulators started to apply pressure for Tesla to perform recalls that would address screen issues and ensure everyone got a better and more reliable screen unit. The recall in total covered 135,000 Tesla EVs, including the 2012-2018 Model S, and the 2016-2018 Model X.

Unfortunately this widespread recall was for an eMMC failure (issues with the embedded memory within the screen device, resulting in blank screens). While Tesla continue to fix leaking screens under the warranty, there hasn’t been any recalls for leaking screens – only the eMMC failure.

The reason the National Highway Traffic Safety Administration (NHTSA) put so much pressure on Tesla wasn’t focused on poor screen quality, but more because of the lack of alternatives for controlling key features. The fact is that on these Tesla cars, if and when the MCU becomes defective, then the entire functionality of the vehicle is impacted.

On other vehicles, if the infotainment touchscreen isn’t working, then you might lose built-in navigation and your ability to connect your smartphone to the system, but you can still operate climate controls, as well as tools like the defogger and rear-view camera. In a Tesla, you can’t because they’re all housed within the MCU.

Users of MCU2 have noted that when resetting glitchy screens, there is now minimal loss of function. In fact, besides the HVAC shutting off while a reset happens, the remaining functions, including AutoPilot all remain active.

However, no active screen does mean that there is no audio chime or other confirmation that key features like turn signals are working — though users have confirmed that lights and signals do in fact all work.

At least a recall order allowed the owners of those 135,000 Tesla vehicles to get new screens that would stand up better to the temperature fluctuations that are a reality in the automotive world.

If you have one of the recalled models mentioned above and haven’t acted on your recall, you should contact your Tesla Customer Service Center ASAP to look into that. In the meantime, even with an apparently fixed or replaced screen, try to avoid leaving your Tesla vehicle in locations where it will get hardcore sun baking down on it for many hours at a time.

If screens are glitching, you can try simple fixes like pressing down on both scroll buttons to reset the screens (hold for about 10 seconds). You can also try a soft reboot of the entire car while parked by holding on the brake and then pressing the scroll buttons. This power cycling process is often enough to fix glitching screens.

I used to work for a laptop manufacturer doing support, and we were instructed that in the event that a customer ever called reporting a leaking LCD we were to IMMEDIATELY tell them to hang up the phone, call emergency services, and get a hazmat team onsite, while we escalated the call to our internal dedicated safety response team. That seems like a pretty harsh response (it"s more severe than what I would have been expected to do for anything short of "My laptop set my house on fire") so I"m inclined to think this stuff isn"t especially safe. It may be true that it"s only a hazard if ingested, though; based on my semi-limited knowledge of the chemistry involved that seems possible. If it were me, though, I"d take the extra cautious route just in case.

(In practice, this basically never happens short of a severe puncture like a blade would cause because of the way these things are manufactured. I"ve actually never personally heard of a situation where an LCD was leaking short of taking a bullet.) EDIT: Let me just make this stronger. This hardly ever happens, ever, anywhere, ever - it"s designed to prevent exactly this sort of problem. Unless you actually witness it in action there is probably no reason to worry about it. See further discussion in comments.

If you find somewhere in the system with oil traces, probably that is the leakage point. This inspection method can’t position precisely because the leakage point is usually very tiny and many parts of the refrigeration system are barely visible. Unless it’s a big leakage point due to sudden break and the leaking liquid is colored.

It applies the principle that fluorescent leak detector will emit a bright yellow-green under the UV / blue light leak detector. It could be used as detection for fluid leakage in various types of systems. What you need to do is just to add the fluorescent agent to the system according to a certain proportion. And after the system operates for 20 minutes, wear special glasses and shine the outside of the system with the leakage light detector. The leakage points will be yellow fluorescent.

Resolution is a key feature of any monitor. It measures the width and height of the screen in terms of pixels, or “picture elements”, the tiny points of illumination that compose an image. A 2,560 × 1,440 screen, for example, has a total of 3,686,400 pixels.

Common resolutions include 1,920 × 1,080 (sometimes called “Full HD” or FHD), 2,560 × 1,440 (“Quad HD”, QHD, or “Widescreen Quad HD”, WQHD), or 3840 × 2160 (UHD, or “4K Ultra HD”). Ultrawide monitors are also available with resolutions such as 2560 x 1080 (UW-FHD) and 3440 x 1440 (UW-QHD), 3840x1080 (DFHD), and 5120x1440 (DQHD).

The pixels being counted in these measurements are usually rendered the same way: As squares on a two-dimensional grid. To see this, you can either move closer to (or magnify) the screen until you perceive individual blocks of color, or zoom in on an image until it becomes “pixelated”, and you see a staircase of small squares instead of clean diagonal lines.

Beyond increasing the detail onscreen in games or movies, there"s another benefit to higher resolutions. They give you more desktop real estate to work with. That means you get a larger workspace on which to arrange windows and applications.

You might already know that a screen with 4K display resolution doesn"t magically make everything it displays look 4K. If you play a 1080p video stream on it, that content usually won"t look as good a 4K Blu-ray. However, it may still look closer to 4K than it used to, thanks to a process called upscaling.

Monitors can also change resolution. Modern screens have a fixed number of pixels, which defines their "native resolution" but can also be set to approximate lower resolutions. As you scale down, onscreen objects will look larger and fuzzier, screen real estate will shrink, and visible jaggedness may result from interpolation. (Note that it wasn’t always this way: older analog CRT monitors can actually switch between resolutions without interpolation, as they do not have a set number of pixels.)

Screens with 4K resolution and higher introduce another scaling concern: at ultra-high definition, text and interface elements like buttons can start to look small. This is especially true on smaller 4K screens when using programs that don’t automatically resize their text and UI.

Windows’ screen scaling settings can increase the size of text and layout elements, but at the cost of reducing screen real estate. There’s still a benefit of increased resolution, even when this scaling is used — onscreen content, like an image in an editing program, will appear at 4K resolution even if the menus around it have been rescaled.

Manufacturers measure screen size diagonally, from corner to corner. A larger screen size, in tandem with a higher resolution, means more usable screen space and more immersive gaming experiences.

Players sit or stand close to their monitors, often within 20”-24”. This means that the screen itself fills much more of your vision than an HDTV (when seated at the couch) or a smartphone/tablet. (Monitors boast the best ratio of diagonal screen size to viewing distance among common displays, with the exception of virtual reality headsets). The benefits of 1440p or 4K resolution are more immediately perceptible in this close-range situation.

Basically, you want to find a screen where you never perceive an individual pixel. You can do this using online tools that measure pixel density (in pixels per inch), which tells you the relative “sharpness” of the screen by determining how closely pixels are packed together, or the alternative pixels per degree formula, which automatically compares its measurements against the limits of human vision.

It"s also worth considering your own eyesight and desktop setup. If you have 20/20 vision and your eyes are around 20” from your screen, a 27” 4K panel will provide an immediate visual upgrade. However, if you know your eyesight is worse than 20/20, or you prefer to sit more than 24” away, a 1440p panel may look just as good to you.

A monitor"s aspect ratio is the proportion of width to height. A 1:1 screen would be completely square; the boxy monitors of the 1990s were typically 4:3, or “standard”. They have largely been replaced by widescreen (16:9) and some ultrawide (21:9, 32:9, 32:10) aspect ratios.

Most online content, such as YouTube videos, also defaults to a widescreen aspect ratio. However, you"ll still see horizontal black bars onscreen when watching movies or TV shows shot in theatrical widescreen (2.39:1, wider than 16:9), and vertical black bars when watching smartphone videos shot in thinner “portrait” mode. These black bars preserve the original proportions of the video without stretching or cropping it.

UltrawidesWhy opt for an ultrawide screen over regular widescreen? They offer a few advantages: They fill more of your vision, they can provide a movie-watching experience closer to the theater (as 21:9 screens eliminate “letterboxing” black bars for widescreen films), and they let you expand field of view (FOV) in games without creating a “fisheye” effect. Some players of first-person games prefer a wider FOV to help them spot enemies or immerse themselves in the game environment. (But note that some popular FPS games do not support high FOV settings, as they can give players an advantage).

Curved screens are another common feature on ultrawide monitors. These can correct one typical issue with larger ultrawides: Images at the distant edges of the screen look less distinct than those in the middle. A curved screen helps compensate for this and provides a clearer view of the extreme edges of the screen. However, its benefits are most noticeable on larger screens over 27”.

Contrast RatioContrast ratio, one of the most basic measures of a monitor"s performance, measures the ratio between the extremes of black and white that the screen can display. A baseline contrast ratio like 1,000:1 means that the white parts of the image are 1,000 times brighter than the dark parts.

Use caution when LCDs advertise very high “dynamic contrast ratios”, which are achieved by changing the behavior of the backlight. For gaming or everyday use, the standard “static” contrast ratio discussed above is a better marker of the monitor"s quality.

LuminanceBrightness is often measured in “luminance”, a precise measure of how much light is emitted by the screen. It"s given in candelas per square meter (cd/m2), a unit which is also called a “nit”. For HDR displays, the VESA (Video Electronics Standards Association) has standardized a suite of tests for luminance using specific test patches. When comparing luminance specs, check to make sure they use this consistent test platform, rather than a proprietary metric.

Black LevelIn all LCD screens, light from the backlight inevitably leaks through the liquid crystal. This provides the basis for the contrast ratio: For example, if the screen leaks 0.1% of the illumination from the backlight in an area that"s supposed to be black, this establishes a contrast ratio of 1,000:1. An LCD screen with zero light leakage would have an infinite contrast ratio. However, this isn"t possible with current LCD technology.

“Glow” is a particular issue in dark viewing environments, which means that achieving low black levels is a major selling point for LCD monitors. However, an LCD screen can’t reach a black level of 0 nits unless it’s completely turned off.

OLEDs have incredible black levels because they don"t use backlights. When an OLED pixel isn"t activated by electricity, it creates no light at all. OLED screens may advertise black levels “below 0.0005 nits”, as taking measurements more precise is usually prohibitively expensive. However, the black level is usually much closer to 0 than 0.0005.

Color DepthMonitors need to display many subtle shades of color. If they can"t smoothly transition between slightly different hues, we see onscreen color “banding” — a stark shift between two different colors, creating visibly lighter, and darker bands where we should see a seamless gradient. This is sometimes referred to as “crushing” the colors.

A monitor"s ability to display many slightly different colors, and thus avoid banding and inaccuracy, is measured by color depth. Color depth specifies the amount of data (measured in bits) the screen can use to build the color of one pixel.

Each pixel onscreen has three color channels — red, green, and blue — illuminated at varying intensities to create (typically) millions of shades. 8-bit color means that each color channel uses eight bits. The total number of shades possible in a screen with 8-bit color depth is 28 x 28 x 28=16,777,216.

Some inexpensive LCD panels use 6-bit color along with “dithering” to approximate 8-bit color. In this context, dithering means the insertion of similar, alternating colors next to one another to fool the eye into seeing a different in-between color that the monitor cannot accurately display.

Frame Rate Control, or FRC, alternates different colors with each new frame to achieve this. While this can be implemented more cheaply than 8-bit True Color, color accuracy suffers, especially in low-light environments. Some screens also feature 8-bit color depth with an additional FRC stage (commonly listed as “8-bit + FRC”) to approximate 10-bit color.

Monitors sometimes feature a Look-Up Table (LUT) corresponding to a higher color depth, such as 10-bit color. This helps speed up color correction calculations that take place within the monitor as it converts color input to a color output appropriate for your screen. This intermediate step can help create smoother color transitions and more accurate output. These are usually reserved for more professional grade monitors than general consumer and gaming displays.

Monitors advertising "99% sRGB" are claiming the screen covers 99% of the sRGB color gamut, which is often considered indistinguishable from 100% when viewed with the naked eye.

In LCD screens, the backlight and color filters determine the color space. All of the light created by the backlight passes through a color filter with red, green, and blue spots. Narrowing the “band-pass” of this filter restricts the wavelengths of light that can pass through, increasing the purity of the final colors produced. Although this lessens the screen"s efficiency (as the filter now blocks more of the backlight"s output), it creates a wider color gamut.

HDR monitors display brighter images with better contrast and preserve more detail in both light and dark areas of the screen. Using an HDR monitor, you might be better able to spot something moving down a dark corridor in a horror game, or see more dramatic shafts of sunlight in an open-world title.

For LCD displays, a high-end backlight feature called local dimming is critical to HDR quality. Dimming zones for the backlight behind the screen control the brightness of groups of LEDs; more dimming zones means more precise control, less “blooming” (where light areas of the image brighten dark ones), and generally improved contrast.

Edge-lit local dimming relies on groups of LEDs clustered around the edges of the screen to brighten or dim the image in what is typically a fairly limited number of dimming zones.

Full Array Local Dimming (FALD), a more high-end option, uses far more dimming zones (typically hundreds) directly behind the panel rather than just at the edges of the screen. It can give more finite control of the HDR content and dimming of the screen as a result.

On the low end, a DisplayHDR 400 screen can have a peak brightness of 400 nits (compared to a 300-nit standard monitor), but only needs a standard 95% sRGB color gamut and 8-bit color depth. DisplayHDR 400 doesn"t require backlight local dimming.

On the higher end, a DisplayHDR 600 screen needs a brightness of 600 nits, 90% of the DCI-P3 color gamut (providing a wider color space), 10-bit color depth, and some form of local dimming.

Refresh rate is the frequency at which your entire screen refreshes the image. Higher refresh rates make onscreen motion look smoother, because the screen updates the position of each object more rapidly. This can make it easier for competitive players to track moving enemies in a first-person shooter, or just make a screen feel more responsive as you scroll down a webpage or open an app on your phone.

However, you"ll only actually see those extra frames onscreen if you have a refresh rate that matches or exceeds them; similarly, you only benefit from a high refresh rate screen if you have a CPU and graphics card capable of high frame rates. Plan your build accordingly to get the full benefit from your hardware.

Response times must be fast enough to keep up with the refresh rate. On a 240Hz screen, for example, a new frame is sent to the screen every 4.17 milliseconds (1000/240 = 4.17).

Players sometimes confuse response time with input lag, a measurement of the delay before your actions appear onscreen, similarly measured in milliseconds. Input lag is felt rather than seen, and is often a priority for players of fighting games and first-person shooters.

Input lag is a side effect of the processing done by the monitor scaler and the screen"s internal electronics. Selecting “Game Mode” on your monitor"s adjustment menu often switches off image processing features and lessens input lag. Disabling VSync (which prevents some visual artifacts) in in-game option menus can also help reduce input lag.

Adaptive SyncScreen tears will be instantly familiar to most players: A graphical glitch that appears as a horizontal line on your screen, with slightly mismatched images above and below it.

The glitch involves both your graphics card and monitor. The GPU draws a varying number of frames per second, but the monitor refreshes its screen at a fixed rate. If the GPU is midway through overwriting the previous frame in the frame buffer when the monitor reads the frame buffer to refresh the screen, the monitor will display the mismatched image as-is. The top of the image might be a new frame, but the bottom section will still show the previous frame, creating the “tear”.

AMD Radeon FreeSync monitors operate along similar lines, matching the display to GPU output to avoid screen tearing and stutters. Rather than using a proprietary chip, they"re built on open Adaptive Sync protocols, which have been built into DisplayPort 1.2a and all later DisplayPort revisions. Though FreeSync monitors are often cheaper, the trade-off is that they aren"t subject to standard testing before release, and vary widely in quality.

Both LCDs and OLEDs "sample and hold", displaying moving objects as a series of static images that are rapidly refreshed. Each sample remains onscreen until it"s replaced with the next refresh. This "persistence" causes motion blur, as the human eye expects to track objects smoothly rather than see them jump to a new position. Even at high refresh rates, which update the image more often, the underlying sample-and-hold technology causes motion blur.

Motion blur reduction features use backlight strobing to shorten the time that frame samples are displayed onscreen. The screen turns black after every sample before displaying the next, reducing the time that a static image is held onscreen.

This mimics the operation of older CRT monitors, which worked differently than current LCD technology. CRT screens were illuminated by phosphors that rapidly decayed, providing brief impulses of illumination. This meant that the screen was actually dark for most of the refresh cycle. These quick impulses actually created a smoother impression of motion than sample-and-hold, and motion blur reduction features work to replicate this effect.

Because the backlight is being rapidly turned off and on, these features also lessen the brightness of the display. If you"re planning to use motion blur reduction backlight strobing, ensure that the screen you"re buying has high peak brightness.

CRTs used three bulky electron guns to send a beam to excite red, green, and blue phosphors on the screen. These phosphors decayed within a few milliseconds, meaning the screen was illuminated by brief impulses on each refresh. This created a smooth illusion of motion, but also visible flickering.

Liquid Crystal Display (LCD)In TFT LCDs (thin-film-transistor liquid crystal displays), a backlight shines light through a layer of liquid crystals that can twist, turn, or block it. The liquid crystals do not emit light themselves, which is a key difference between LCDs and OLEDs.

Older LCDs used Cold-Cathode Fluorescent Lamps (CCFLs) as backlights. These large, energy-inefficient tubes were incapable of controlling the brightness of smaller zones of the screen, and were eventually phased out in favor of smaller, energy-efficient light-emitting diodes (LEDs).

LCD panels are available in a range of technologies and can vary widely in color reproduction, response time, and input lag, especially among high-end options. However, the following generalizations about panels usually hold true:

Oldest and most affordable LCD panel type. High refresh rates and response times for high-speed gaming such as first-person shooters or fighting games.

Pale glow, known as “IPS glow” visible when viewing screens in dark rooms from off-center angles. Response times usually worse than TN panels, but better than VA panels. Lower contrast ratio than VA panels.

Organic Light-Emitting Diode (OLED)OLED screens are emissive, meaning they create their own light, rather than transmissive screens that require a separate light source (like LCDs). Here, the application of electric current causes a layer of organic molecules to light up on the front of the screen.

Backlights may be imperfectly blocked by the liquid crystals in an LCD, causing black areas of an image to appear gray. Because OLEDs have no backlight, they can achieve “true black” by simply turning off a pixel (or at least 0.0005 nits, the lowest measurable brightness).

OLEDs therefore boast very high contrast ratios and vibrant color. The elimination of the backlight also makes them slimmer than LCDs. Much as LCDs were a thinner, more energy-efficient evolution of CRTs, OLEDs may prove a thinner evolution of LCDs. (They can also be more energy-efficient when displaying dark content, like movies, but less energy-efficient with white screens, such as word processing programs).

You"ll find a multitude of ports behind or beneath your monitor. Display interfaces connect your screen to graphics output from your PC, while USB and Thunderbolt™ ports provide data and power to external devices.

Stockwell Elastomerics is a leading provider of gaskets for touch screens, displays and integrated touch panel assemblies that serve several functions: sealing, load distributing, gap filling, mechanical shock protection and over-press cushioning.

Often a touch screen gasket or display gasket will help spread the compression load of the housing or bezel on the display. Without a gasket, the enclosure that holds the display in place can create pressure points on the display. In some cases, these pressures can cause distortions, false contacts or short circuits.

Similar to load distributing, touch panel gaskets are used to fill gaps between the screen and the display and/or the screen and bezel. The display gasket will take up gaps generated by tolerance stack-ups in the device.

Display gaskets offer some degree of cushioning to protect the display from damage due to mechanical shock. In the event that a device is dropped or banged, the gasket will act as a touchscreen cushion, offering a limited amount of protection.

Touchscreen gaskets also serve as display cushions when a user presses on the display too hard. The gasket deflects, takes up and spreads the load offering some protection from over-press or overloading in a small area.

LCD dust seals and touch screen dust seals are the most basic requirement of display gasketing. These are often static (not portable), indoor applications where the device is not to be exposed to water. Sealing can be achieved by closed cell sponge materials or fine pore open cell materials such as PORON urethane foam.

Portable electronics or touchscreens used by the public such as gaming touchscreens or indoor information kiosks inevitably will be exposed to some water. This can come from cleaning and beverage splashing, or for portable devices – rain. These electronic devices are also more likely to be exposed to mechanical shocks, such as banging or dropping. Closed cell or compressed microcellular foam materials will offer more protection against incidental, light water exposure.

Light leaking is sometimes a concern with certain LCD or LED display applications. This can be addressed with black gasketing with either a very thin adhesive or a black supported adhesive. A common material configuration for this is soft PORON urethane foam with 3M 9795B adhesive. The 3M 9795B is a film supported double coat adhesive with a black PET support layer that does not pipe light.

Touchscreen gaskets and display gaskets tend to have narrow walls that don’t always lend themselves to easy installation. This can be addressed in a few ways such as fixturing or utilizing the centers as temporary supports. The preferred adhesives for touchscreen gaskets and display gaskets are repositionable adhesives such as Adchem 8311M or 3M 9415 depending on the bond strength required. Stockwell Elastomerics also offers medium and high bond strength adhesives for permanent bonding. View the current listing of pressure sensitive adhesive options.

Most touch panel or touch screen manufacturers offer guidelines for gasketing. These typically show the active screen area, viewing area, and the gasket area. The manufacturer offers various recommendations on adhesive strength and gasket material type, but caution should be taken since each application will vary.

Broad recommendations such as “closed cell foam” do not take into consideration factors such as stress relaxation, compression set, long term sealing performance, outgassing, plasticizer interaction, cost, and manufacturability. Over-designing the gasket can drive the cost up, whereas under designing could result in damaged devices and leaks when the units are in the field. Stockwell Elastomerics can offer guidance on design and manufacturability of touchscreen gaskets or touch panel gaskets. Key design points include:

The interior opening of the gasket should follow the touch screen manufacturer’s recommendation that stays clear of the active area. The outer dimension are defined by the available space behind the bezel or in the case. A rough rule of thumb is that the gasket wall should be 1.5x the thickness. (Example: .062″ thick gasket should have a gasket with .093″ or greater flange width.) This allows for die cutting and makes for a stable gasket when installed. A gasket that is taller than it is wide tends to fold over during compression. The exception to this is when the gasket is captive in a groove.

It is important to keep in mind the clamping loads. While wider gasket walls generally seal better, the overall surface area is directly related to the loads applied to the LCD and touchscreen. Compression Force Deflection curves of various materials are available to aid designers.

The gasket thickness will depend on the designed gap in the enclosure, the fastening scheme, rigidity of the housing and the level of sealing required. Many touch screen gaskets are thin and soft but as the display gets larger the tolerance stacks typically get larger as well. This may require a thicker gasket depending on the fastener locations.