lcd touch screen dead spot manufacturer

If your screen is getting unresponsive in some specific places don"t worry too much, you are not alone. It"s a known issue that has been affecting different devices, brands and Android versions. The usual "dead" spots are placed on the four corners, the middle of the screen or some letters when you open the keyboard. Thanks to the community feedback there are some simple fixes that, most likely, will solve your problem. Check them out and tell us if they did the trick for you. Please, feedback is the key

- Clean Master. There"s an special feature called "iswipe" that has been causing different screen problems for some users. Disable or, even better, uninstall this app. It"s possible that you"ll need to uncheck it first in settings - security - device administrators.

- There are a few reports about Samsung Pay or Droid Optimizer causing screen issues that stopped after disabling any of these apps. There"s not much feedback about these apps though, but still worth a try.

Safe mode. This process will temporarily disable every app that didn"t come preinstalled in your phone. If the problem doesn"t appear while your phone is running in safe mode then it means that you have a tedious task ahead. Reboot your phone to exit safe mode and start disabling, one by one, your apps until you find the culprit. You should start with apps that you downloaded or updated right before the problem started and any app with fancy screen features like bubbles, swipe or lock options. Just be aware that some of the apps listed before do come preinstalled in some phones/brands, so they will run even in safe mode!

Developer options. If you"re still reading this there"s a big chance that nothing worked for you and maybe your phone has a hardware problem. There"s an easy way to get visual feedback every time you touch the screen so you can check if there are any real dead spots. You need to have the developer options enabled so if they are still disabled go to settings - about phone - scroll down and tap 7 times on the Build number until they open.

Now, tap & swipe over those places where you are having issues. If you don"t get a visual feedback (broken line when swiping) or the coordinates don"t change, there"s a big chance that you need to visit a repair shop or make use of the warranty. You can see in the screenshot how these options work

A few days ago the lower part of my device"s touchscreen went dead. Whenever I touched the bottom 2 to 3 centimetres of my screen, it simply wouldn"t respond, meaning that the spacebar and a few of the letters on the keyboard didn"t work, along with the buttons in some apps. So I did some research on Google, tried a few solutions ranging from performing a soft reset to taking the phone apart and making sure all the parts were connected correctly, but no luck. A few hours later, my phone ran out of battery and when I restarted it the problem had gone, only to return about 15 minutes later. Therefore, I"m pretty convinced that the problem is software rather than hardware based and am reluctant to perform a hard reset or to replace the digitiser. What should I do instead?

You possibly can relate with how much you take good care of your touch screen when your mobile device is either used, charged, placed in a handful bag, or kept in a pocket. It"s always applied with great care. This is solely because your touch screen is an essential component of your mobile device, and you can not afford to cope with the middle part of touch screen not working.

You might be thinking it can never happen with the extra care attached to it. But it might be otherwise. Can you remember the countless times you tap your touch screen when responding to social media messages? Or when you listen to pop music and another genre when you"re in the restroom?

The middle part of a touch screen is the most-used section of your device"s touch screen. Although, other touch screen parts are also necessary for navigating you through several other functions on your device, yet, you may not necessarily need to fix it immediately. However, you must have a clue on how to fix the middle part of your touch screen.

The crucial task and aspect you need to work on when your middle touch is not working are to inspect if there"s no pointed crack or area on the touch screen. The touch screen is a delicate part that can be affected by a mere simple metal piering or metal attachment. Unknowingly, the damaged middle part may look like a speck of mere dust to you or sometimes colored at a definite spot.

An insight I"ll give you is to check the sides and angles of the middle part for any cracks or breaks. A magnifying glass can help too if you can"t see well. Moreover, it"s also essential you use bright lights in a dim place to detect scratches. If there"s a slight botch on the screen, you may have to consult a repairer.

Another reason why you may experience a faulty middle touch screen is through a water accident. You sometimes spend most of your time with your smartphones at home. Perhaps, when you"re engaged in the kitchen, and when having your bath in the bathroom. Even, you can unknowingly dive into a pool with a phone in your pocket.

Smartphone developers have quite been creating varieties of devices with a water resistor. Yet, for your device that has no water resistor, you need to apply extra care and know-how to detect if your middle touch screen is affected by a water accident.

Do you know your corrupt SD Card can hinder certain parts like the middle touch screen or the entire touch screen of your device from working? Yes, it can. Even though your SD card is an alternative to your internal storage device that allows you to manually store files, images, videos on it. The middle part of your touch screen which might be the most touched part of your device can seize to work when your SD Cards freezes and can lag your operations when it"s corrupted.

It"s easy to unmount your SD card without having to touch the middle part of your touch screen when you want to power off the device. Activate the airplane mode at the top bar and remove the SD card successfully.

Your smartphone can neither be used nor operated without using external attachments like the screen protector, earpiece, and a USB charger from a third-party source. These attachments are not all recommended for your Smartphone. Your middle touch screen can stop working if you use an unsuitable external attachment with the device.

Malicious Android apps are now on a rampage. Some Android apps can serve as a problem for your device if not properly scrutinized before installed. Screen bugs and glitches on the middle part of your touch screen can arise from an unsafe installed app.

For most Android devices, the restart icon is located in the middle of the screen. However, you can perform this by using the power and volume button. This restarts every app that freezes a section of your touch screen.

The safe mode option is another way to clear your middle touch screen off the hooks of not working. This can also be done by the method you used in restarting your device. You can switch your device to safe mode with these simple steps.

Most times, the middle part of touch screen not working is caused by due to hardware damages, which can only be rectified by a trained technician. In that case, we recommend you visit the offial service provider for your brand for assistance.

Slowly drag your finger to the bottom right corner without lifting. Try to move your finger slowly enough that you can count to 10 before reaching the opposite corner of the screen.

Though it"s impossible to gauge how widespread the problem is, a number of users are reporting an issue where certain spots on the iPhone"s MultiTouch screen -- particularly a strip about 1/2 inch in height somewhere below the top of the screen -- will not accept input. If indeed you have a defective screen, Apple is apparently willing to replace it with little hassle. However, to ensure that a more innocuous issue isn"t at play, try the following first:

Reset your iPhone Sometimes, ostensibly dead spots on the screen are merely the result of frozen applications or an unresponsive interface rather than actual hardware failure. Press and hold the Sleep/Wake button (on the top of the unit) and the Home button simultaneously for several seconds until the Apple logo appears and check for persistence of the issue.

Clean the screen It may sound trite, but a glaze of any foreign substance can cause operational difficulties for the iPhone"s screen. Clean the screen with the cleaning cloth that came in the box with the iPhone.

Restore your iPhone As a last resort, try restoring. This can remove lingering software issues that might be causing a lack of screen response. To perform a restore, Connect your iPhone to your Mac or PC and, in iTunes, click the Restore button under the Summary tab. Restoring the phone will erase contacts, calendars, photos and other data on the phone, but will restore automatically backed-up information including text messages, notes, call history, contact favorites, sound settings, widget settings, etc.

Also, if you are indeed experiencing a hardware failure, please drop us a line indicating what version of screen your iPhone uses. To discover this information, put your iPhone in field test mode by accessing the Phone application, tapping Keypad, then entering *3001#12345#* and pressing Call. Tap Versions, then inspect the entry next to LCD Panel ID. Let us know whether your iPhone is a 7 series or 5 series

You probably touch your phone"s screen hundreds of times per day. Combined with its delicate glass build, it"s no surprise that smartphone touchscreens are one of the most common components to run into issues.

But the touch screen not working on your Android phone isn"t always the result of a hardware failure. If your phone touchscreen often isn"t working or fails to respond, there"s a lot you can do before getting professional help.

First, you should rule out the possibility of a software bug if your phone touch screen is not working. There are a handful of troubleshooting steps you can do to confirm this.

A good-old reboot might sound futile to fix such an advanced issue. However, it"s often one of the most successful ways to fix an unresponsive touch screen on Android. Restarting your phone shuts down and refreshes all background services, which could have crashed and led to your issue.

If you"re unable to touch the screen to select the option, on most devices, you can hold down the Power button for several seconds to switch off your phone. In some cases, you may need to hold down the Power button and the Volume Up button at the same time.

If your touch screen is not working, but only intermittently, then you may be able to re-boot your phone into safe mode. Android"s safe mode lets you use your phone with only the original software it shipped with, which strips out all services and apps you"ve installed. If your display works normally in safe mode, a third-party app is likely at fault here.

To enter safe mode on most new Android devices, press and hold the power button. In the resulting prompt, touch and hold the Power off button. Once you see the prompt to enter safe mode, tap OK, and your phone will soon restart. To exit safe mode, just restart your phone normally.

If you"re scratching your head wondering, "Why is my phone touchscreen not working?", you"ll find a range of apps on the Play Store that could help you to diagnose your display issues. These are designed to pinpoint what exactly is wrong with your phone"s touchscreen. We recommend trying out one simply called Display Tester.

When you launch Display Tester, head into its Tests tab. Here, you have the option to test a whole bunch of aspects. The app can detect dead pixels, burn-in on OLED screens, whether the contrast and saturation are accurate, multi-touch status, and more.

If you got positive results in touch-based tests, you should review all recently installed apps or consider performing a factory reset. Since your touchscreen functioned as intended under special circumstances, a third-party app is most likely the root cause.

Many people apply a screen protector on their phones as an added safety against drops and scratches. But that same sheet of plastic or glass could prevent your touch signals from reaching the display panel.

If your phone"s screen has been acting up lately, try removing the protector. Of course, this doesn"t guarantee a fix. However, it could increase the response rate on an already weak screen.

Touchscreen Repair is a lightweight app that calibrates your screen to reduce response times. The app asks you to consecutively tap several sections of the touchscreen. Based on your phone"s internals, it then artificially drops the latency as much as possible.

The effectiveness of Touchscreen Repair varies depending on your phone maker. Many OEMs ship their phones with optimal response rates. In those scenarios, Touchscreen Repair won"t be able to do much. But it"s worth a try if nothing else has worked yet.

You don"t have to rely on touch inputs to control your phone. To better serve users with accessibility needs, voice and facial-based interaction methods for Android have come a long way.

With the right apps, you can navigate on your phone entirely through your voice and facial movements. Of course, these solutions only apply if your phone"s touchscreen works enough to install an app from the Play Store.

Else, you can try installing the app to your phone through the Play Store web interface. And you can disable touchscreen input on your phone until you get the screen fixed.

Google"s Voice Access app proactively listens for your commands and assigns a number to every action available on the screen. Instead of touching an app icon or menu element, you just have to call out the assigned digit.

Voice Access links fundamental actions to fixed phrases. So you can say "screen down" for moving around pages and "go back" to return to the previous screen, for example.

This app does exactly what its name suggests. It adds a virtual cursor on your screen, which you can manipulate with your face. To move the pointer, you simply have to move your head in the appropriate direction.

If you can"t install any apps due to screen problems, connecting an external keyboard and mouse might do the trick. This assumes you can still see the screen, though.

With these possible fixes, you should hopefully be able to revive your phone"s touchscreen if it"s just a software bug. Failing that, the apps mentioned can grant you a temporary workaround.

Otherwise, you will have to visit a service center for help. If you"re lucky, a professional will be able to restore the touchscreen"s functions, although depending on the device, it may be a pricey repair. If not, you"ll have to look at replacing your phone.

Your Android touch screen might not be working for various reasons. Hopefully, one of the fixes above helped solve your touch screen issues. If everything fails, perhaps it"s time to upgrade.

My problem is not with the LCD. Its with the digitizer layer on the display that detects capacitive touch events. One specific area is not detecting touch events.

Once I got the device loaded with all my games and fun stuff, I was ready to take it for a test run. First, I tried to start surfing the web, and I found that I couldn"t type in the letter "c". I did a quick check with the Pointer Location app, and I found an unmistakable dead spot on the touch-screen.

Your iPhone"s touchscreen is its defining feature. In fact, an iPhone is essentially useless without a working touchscreen, so if it fails to respond to your touch, it"s a problem you need to solve — immediately.

The good news, though, is that unless there"s a fatal hardware problem that requires a trip to an Apple store to get the entire phone repaired or replaced, you may be able to get it up and running again with a few simple fixes.Quick tip: If your iPad touch screen isn"t working either, there are several other ways to troubleshoot the issue.

If your iPhone"s touchscreen is not working, try each of these troubleshooting tips. Hopefully, one of these will get you up and running. If not, it"s likely you have a hardware problem that may only be fixable by contacting Apple customer service to repair or replace your phone.

If your iPhone has gone completely haywire, the first thing you should do is restart it — turn it off completely, wait a minute or two, and then turn it on again. Restarting an iPhone can wipe out temporary glitches in memory, which can restore, for example, an unresponsive screen.

Of course, if the touchscreen is not working, you can"t shut down the phone in the usual way using the Settings menu; you"ll need to force the phone to restart by pressing some combination of power and volume buttons.

The iPhone uses a capacitive touchscreen that senses your fingertips using electrical conductance. That means various things can interfere with the way your screen works — dirt and grime can affect it, but a much larger problem is moisture and liquid. If the screen is wet or even just damp, dry it thoroughly and try again.

The Whoosh! Cleaning kit is an inexpensive solution to keeping your iPhone screen clean and working properly. We chose it as one of the best iPhone accessories you can buy.Whoosh! Screen Cleaning Kit, $9.99 from Amazon and Target

On rare occasions, an accessory plugged into the phone"s Lightning port could interfere with the touchscreen. If anything is plugged into the port — including a power bank or charger — unplug it. If that solves your problem, the accessory or cable might be incompatible with the iPhone.

The iPhone"s touchscreen may seem robust enough to work virtually flawless all the time, but it only works properly in a surprisingly narrow set of conditions. For example, the touchscreen can stop working if you apply a screen protector that"s too thick, making it impossible for the screen to sense the electrical capacitance in your fingers.

If the touchscreen isn"t working — or is working intermittently — remove anything on or around the screen, including the phone case and any screen protector that"s keeping the screen from getting scratched. If it works after removing those accessories, get a different case and/or look for a thinner screen protector.

If your iPhone has recently stopped responding to your touch and nothing else so far has worked, it"s possible there"s a serious hardware issue and the phone needs to be repaired or replaced.

4. On a Mac, you should see the option to restore or update your iPhone. Click Restore and follow the directions to perform a factory reset. On a PC, click the Device button in the top left of iTunes. Then select Summary, then Restore, and follow the onscreen instructions.

If you still have no luck getting the touchscreen to respond, it"s almost certain that you have a hardware problem with your iPhone and it needs professional help. Contact Apple"s customer support to see if it is eligible for repair or replacement.Dave Johnson

Under Device Specifications, if the Pen and touch section reads No pen or touch input is available for this display, the computer does not have a touch screen.

NOTE: For touch-enabled Dell monitors, verify that the USB cable is connected from the monitor to the computer to enable the touch screen feature. To learn more about how to connect the USB cable between the monitor and the computer, see the User Guide of the Dell monitor.

To clean the anti-static screen, we recommend using a special screen-cleaning tissue or solution that is suitable for the anti-static coating on LCD panels.

NOTE: In some cases, the screen protector or screen guard may prevent the touch screen from registering that you are touching the screen and may need to be removed (this may occur if it is not designed for a capacitive touch screen or if it has air bubbles in it).

NOTE: Using a non-standard or unsupported digital pen, stylus, or regular pen to write can damage the touch screen. Select Dell 2-in-1 laptops are compatible with digital pens like Dell Active Pen. See the User Guide of the Dell 2-in-1 laptop or the Dell Active Pen for more information.

The touch screen of the computer may not respond because it is disabled or it needs to be reinstalled. Use Windows Device Manager to enable or reinstall the touch screen driver.

NOTE: For touch-enabled Dell monitors, verify that the USB cable is connected from the monitor to the computer to enable the touch screen feature. To learn more about how to connect the USB cable between the monitor and the computer, see the User Guide of the Dell monitor.

NOTE: The touch screen drivers are built-in to the latest operating systems such as Windows 10, 8.1, 8, or 7. Windows Update helps download the latest touch screen driver that is applicable to your computer (if required).

NOTE: Using a non-standard or unsupported digital pen, stylus, or a regular pen to write can damage the touch screen. Select Dell 2-in-1 laptops are compatible with digital pens such as the Dell Active Pen. See the User Guide of the Dell 2-in-1 laptop or the Dell Active Pen for more information.

NOTE: If Dell SupportAssist is not installed on your computer, you will be prompted to complete the installation to run the diagnostic test. Follow the on-screen instructions to complete the installation process of Dell SupportAssist.

Power settings can cause the touch screen to stop working after waking the computer from sleep mode. Change the power settings so that the touch screen stays active while the computer is in sleep mode.

Intermittently on my 7390 2-in-1, the touch screen has a dead spot in the lower left hand corner of the screen. The dead area is about 2 inches high by three inches wide. The screen is completely unresponsive to touch in that area, but is responsive to the cursor if I use the touch pad. The screen is responsive elsewhere.

Well, I would like to tell you that the touch screen not working or unresponsive touchscreen on Android is a common issue. And, this issue doesn’t only happen with Android, Apple users also experience the iPhone/iPad touchscreen not working issue.

So, if you have also come across the same issue and want to fix it then this blog is definitely for you. Here you will get to know about how to fix the touchscreen problem on Android?

To fix the Android touchscreen not working issue remove the SD card and SIM card, boot the phone in the safe mode, run antivirus scan, diagnose the phone display, and factory reset your phone. Well, these are not the only ways to deal with this issue. To find out the complete list of solutions, keep reading this guide.

If your Android device touch screen is not physically damaged or smashed and it had stopped working all of a sudden and does not respond to your touch, then this may be caused due to software issues.

If your phone’s touch screen is not working, then it is possible that this issue is appearing due to the system issue. In this situation, it is better to use the Android Repair Tool.

This tool will fix all of the system issues that might be causing this problem on your phone. Not just this, but it can also fix several other problems, such as the phone being stuck in the boot loop, apps crashing issues, black screen of death error, battery issues, and many more.

A soft resetting of the phone is a very basic move but in some cases, it works magically. If the phone touch screen not working is not happening due to any major issue, this trick may get your job done. Here’s how to fix unresponsive touch screen on Android:

Sometimes, the screen damage is not the actual reason for the unresponsiveness. There might be some issue with the memory card or SIM card. In this situation, you should try removing the SD or SIM card from your phone:

Mostly Android touch screen doesn’t work due to the screen protector. Even though a screen protector protects your phone’s screen from damage, dust, scratches, and water drops, it can also cause issues, such as the touchscreen not working.

If there is any scratch on the screen protector or is completely damaged, then thetouchscreen of your phone won’t respond. In this case, the best solution would be to remove the protector.

However, it will only work if the issue is happening due to the screen protector. If it is not working, then there must be some other issue with your phone screen. Hence, follow the other listed solutions.

It is a temporary solution to this issue, but you can use it until you find the actual reason or fix the issue permanently. You don’t only need to rely on the touch screen to control the phone. There are other options too to navigate through the phone.

You can try the 3-party apps to use the face or voice recognition feature to access your phone. However, this trick can only work if your phone touchscreen is at least partially working so that you can download the app.

To control the phone with the voice, you can use Google’s Voice Access app. This app will listen to your commands & assign a number for each action available on the phone screen. After this, you don’t need to tap on the screen.

Now, just call out the assigned number.Voice Access app also fixes the phrases for certain actions. For example, if you say go back, the app will take you back to the previous screen.

The EVA Facial Mouse app is a virtual cursor that can let you navigate through your phone using face recognition technology. To move the phone screen, simply move your phone in that direction.

If the above-given solutions failed for you, then you can try to boot your phone into Safe Mode to fix the problem. It will help you to recognize whether the touchscreen issue is caused due to any of the recently installed apps.

If your Android touchscreen works properly afterbooting the device into the Safe Mode, then it means the recent third-party app was a culprit behind this problem. Once you find out about the troublesome 3rd party app, simply uninstall it on your phone.

If your touch screen problem is not affecting your ability to download apps from the Play Store, then download and install an anti-malware application and scan your device. Maybe this can fix all your problems.

There are various apps available in the Play Store that can calibrate your device’s touch screen and improve its accuracy and responsiveness. These apps are very much effective particularly when your touch screen responds inaccurately or responds too slow.

Open Play Store, type “touch screen calibration” in the search bar and you will get a few results. Check the ratings and read the review carefully before you download them.

Wondering why my phone touchscreen is not working? If so, you should try 3rd party apps tofix display issues on your Android phone. There are so many apps on the Google Play Store that can diagnose the touchscreen problem of your phone.

These apps will help you to pinpoint what is wrong with your phone screen.For this, I recommend using the Display Tester. First, download and install the app on your device and then follow these instructions:

Here, you will get a bunch of options to test the issue from all aspects. With this tool, you can detectburn-in on OLED screens, dead pixels, the accuracy of saturation and contrast, multi-touch status, etc.

If the touch screen is totally unresponsive on an Android phone/tablet, then it is time to perform factory on the device. As doing this will erase all data on your Android device, you should only go with this option if nothing else is working out for you.

If your Android phone or tablet screen has been physically damaged due to several reasons such as a dropped the device in water, on the floor from a high distance, smashing the screen, or breaking the device then the touch screen could be damaged and thus stop responding.

The first thing we are going to do is use the star codes to check if the touchscreen of the Android phone or tablet is working or not. First, dial the start codes compatible with your Android device.

Simply dial the codes, to open the device’s diagnostic mode. Once you enter into diagnostic mode, you can test the touchscreen for bugs and dead zones.

In this case, you can try one trick. Simply, knock each corner of the touch screen 2-3 times and then see if the Android unresponsive touchscreen issue has been resolved or not. If it is still not working, then you can try the next fixes.

There are some instances where the Android touch screen stopped responding after the phone is dropped into the water or due to some reason water drops gets inside the screen.

Nevertheless, you can still fix this problem and get your phone screen back to its normal working condition. For this, you must check out the guide on how to how to fix unresponsive touch screen on Android damaged by water.

This is a straightforward solution, if there is a hardware issue with your phone, then you don’t have any other option but to buy a new touchscreen for your phone.

There are some cases, where the phone touchscreen can be accessed partially. In this situation, the 3rd party apps can help you out in resolving the problem and enhancing the screen latency. There are so many apps that can calibrate the phone screen to decrease the response time.

This tool will suggest you click on several sections of the touchscreen. After doing this, the app will reduce the latency according to the phone model.

Many people ask how to fix unresponsive touch screen Android but before that, is important to know what are the reasons for the touch screen not working on Android, right?

Physical damage– Maybe your Android phone is damaged or broken. Or maybe it’s due to moisture detected issues, high temperature, static electricity, cold, etc can lead to touch screen damage on Android phones.

The Android touch screen is not working/became unresponsive? Now, wondering how to recover data from an unresponsive touch screen of an Android phone?

You can use the user guide to find out how Android Data Recovery Toolworks in order to recover data from an Android device with an unresponsive touch screen.

Yes, the cracked screen affects the responsiveness of the touchscreen. When the phone screen gets cracked, the digitizer, an important component of the phone, starts interrupting the touch of the screen. But when the phone screen totally get damaged, the digitizer gets exposed to water, dust, moisturewhich leads to major damage.

If you see a phone’s screen then it has two major parts: the actual LCD and the glass. The glass of the screen can be replaced easily but when the LCD gets damaged the repairing of the device becomes a risky task.

There are ways to fix the cracked screen temporarily. You can use a screen protector or tape to fix it. First, clean the phone screen as much you can and put packaging tape over the screen. If there is some extra tape then remove it. And now you can use the phone as before but remember, it’s a temporary fix.

Though the most Android phone touchscreen issue can be solved by removing the screen protector and cleaning the screen with a soft, slightly damp, lint-free cloth. but if that doesn’t work, you can try the other ways shared in this blog to solve how to fix unresponsive touch screen Android phone issue.

On the other, you may also lose your important and valuable data from your device, hence it is recommended that you must try Android Data Recovery Softwareto recover data from an Android device whose touch screen is not working or became unresponsive.

Apple has determined that some iPhone X displays may experience touch issues due to a component that might fail on the display module. An affected device may exhibit the following:

If your iPhone X has any damage which impairs the ability to complete the repair, such as a cracked screen, that issue will need to be resolved prior to the service. In some cases, there may be a cost associated with the additional repair.

A touchscreen or touch screen is the assembly of both an input ("touch panel") and output ("display") device. The touch panel is normally layered on the top of an electronic visual display of an information processing system. The display is often an LCD, AMOLED or OLED display while the system is usually used in a laptop, tablet, or smartphone. A user can give input or control the information processing system through simple or multi-touch gestures by touching the screen with a special stylus or one or more fingers.zooming to increase the text size.

The touchscreen enables the user to interact directly with what is displayed, rather than using a mouse, touchpad, or other such devices (other than a stylus, which is optional for most modern touchscreens).

Touchscreens are common in devices such as game consoles, personal computers, electronic voting machines, and point-of-sale (POS) systems. They can also be attached to computers or, as terminals, to networks. They play a prominent role in the design of digital appliances such as personal digital assistants (PDAs) and some e-readers. Touchscreens are also important in educational settings such as classrooms or on college campuses.

The popularity of smartphones, tablets, and many types of information appliances is driving the demand and acceptance of common touchscreens for portable and functional electronics. Touchscreens are found in the medical field, heavy industry, automated teller machines (ATMs), and kiosks such as museum displays or room automation, where keyboard and mouse systems do not allow a suitably intuitive, rapid, or accurate interaction by the user with the display"s content.

Historically, the touchscreen sensor and its accompanying controller-based firmware have been made available by a wide array of after-market system integrators, and not by display, chip, or motherboard manufacturers. Display manufacturers and chip manufacturers have acknowledged the trend toward acceptance of touchscreens as a user interface component and have begun to integrate touchscreens into the fundamental design of their products.

The prototypeCERNFrank Beck, a British electronics engineer, for the control room of CERN"s accelerator SPS (Super Proton Synchrotron). This was a further development of the self-capacitance screen (right), also developed by Stumpe at CERN

One predecessor of the modern touch screen includes stylus based systems. In 1946, a patent was filed by Philco Company for a stylus designed for sports telecasting which, when placed against an intermediate cathode ray tube display (CRT) would amplify and add to the original signal. Effectively, this was used for temporarily drawing arrows or circles onto a live television broadcast, as described in US 2487641A, Denk, William E, "Electronic pointer for television images", issued 1949-11-08. Later inventions built upon this system to free telewriting styli from their mechanical bindings. By transcribing what a user draws onto a computer, it could be saved for future use. See US 3089918A, Graham, Robert E, "Telewriting apparatus", issued 1963-05-14.

The first version of a touchscreen which operated independently of the light produced from the screen was patented by AT&T Corporation US 3016421A, Harmon, Leon D, "Electrographic transmitter", issued 1962-01-09. This touchscreen utilized a matrix of collimated lights shining orthogonally across the touch surface. When a beam is interrupted by a stylus, the photodetectors which no longer are receiving a signal can be used to determine where the interruption is. Later iterations of matrix based touchscreens built upon this by adding more emitters and detectors to improve resolution, pulsing emitters to improve optical signal to noise ratio, and a nonorthogonal matrix to remove shadow readings when using multi-touch.

The first finger driven touch screen was developed by Eric Johnson, of the Royal Radar Establishment located in Malvern, England, who described his work on capacitive touchscreens in a short article published in 1965Frank Beck and Bent Stumpe, engineers from CERN (European Organization for Nuclear Research), developed a transparent touchscreen in the early 1970s,In the mid-1960s, another precursor of touchscreens, an ultrasonic-curtain-based pointing device in front of a terminal display, had been developed by a team around Rainer Mallebrein[de] at Telefunken Konstanz for an air traffic control system.Einrichtung" ("touch input facility") for the SIG 50 terminal utilizing a conductively coated glass screen in front of the display.

In 1972, a group at the University of Illinois filed for a patent on an optical touchscreenMagnavox Plato IV Student Terminal and thousands were built for this purpose. These touchscreens had a crossed array of 16×16 infrared position sensors, each composed of an LED on one edge of the screen and a matched phototransistor on the other edge, all mounted in front of a monochrome plasma display panel. This arrangement could sense any fingertip-sized opaque object in close proximity to the screen. A similar touchscreen was used on the HP-150 starting in 1983. The HP 150 was one of the world"s earliest commercial touchscreen computers.infrared transmitters and receivers around the bezel of a 9-inch Sony cathode ray tube (CRT).

In 1977, an American company, Elographics – in partnership with Siemens – began work on developing a transparent implementation of an existing opaque touchpad technology, U.S. patent No. 3,911,215, October 7, 1975, which had been developed by Elographics" founder George Samuel Hurst.World"s Fair at Knoxville in 1982.

In 1984, Fujitsu released a touch pad for the Micro 16 to accommodate the complexity of kanji characters, which were stored as tiled graphics.Sega released the Terebi Oekaki, also known as the Sega Graphic Board, for the SG-1000 video game console and SC-3000 home computer. It consisted of a plastic pen and a plastic board with a transparent window where pen presses are detected. It was used primarily with a drawing software application.

Touch-sensitive control-display units (CDUs) were evaluated for commercial aircraft flight decks in the early 1980s. Initial research showed that a touch interface would reduce pilot workload as the crew could then select waypoints, functions and actions, rather than be "head down" typing latitudes, longitudes, and waypoint codes on a keyboard. An effective integration of this technology was aimed at helping flight crews maintain a high level of situational awareness of all major aspects of the vehicle operations including the flight path, the functioning of various aircraft systems, and moment-to-moment human interactions.

In the early 1980s, General Motors tasked its Delco Electronics division with a project aimed at replacing an automobile"s non-essential functions (i.e. other than throttle, transmission, braking, and steering) from mechanical or electro-mechanical systems with solid state alternatives wherever possible. The finished device was dubbed the ECC for "Electronic Control Center", a digital computer and software control system hardwired to various peripheral sensors, servos, solenoids, antenna and a monochrome CRT touchscreen that functioned both as display and sole method of input.stereo, fan, heater and air conditioner controls and displays, and was capable of providing very detailed and specific information about the vehicle"s cumulative and current operating status in real time. The ECC was standard equipment on the 1985–1989 Buick Riviera and later the 1988–1989 Buick Reatta, but was unpopular with consumers—partly due to the technophobia of some traditional Buick customers, but mostly because of costly technical problems suffered by the ECC"s touchscreen which would render climate control or stereo operation impossible.

Multi-touch technology began in 1982, when the University of Toronto"s Input Research Group developed the first human-input multi-touch system, using a frosted-glass panel with a camera placed behind the glass. In 1985, the University of Toronto group, including Bill Buxton, developed a multi-touch tablet that used capacitance rather than bulky camera-based optical sensing systems (see History of multi-touch).

The first commercially available graphical point-of-sale (POS) software was demonstrated on the 16-bit Atari 520ST color computer. It featured a color touchscreen widget-driven interface.COMDEX expo in 1986.

In 1987, Casio launched the Casio PB-1000 pocket computer with a touchscreen consisting of a 4×4 matrix, resulting in 16 touch areas in its small LCD graphic screen.

Touchscreens had a bad reputation of being imprecise until 1988. Most user-interface books would state that touchscreen selections were limited to targets larger than the average finger. At the time, selections were done in such a way that a target was selected as soon as the finger came over it, and the corresponding action was performed immediately. Errors were common, due to parallax or calibration problems, leading to user frustration. "Lift-off strategy"University of Maryland Human–Computer Interaction Lab (HCIL). As users touch the screen, feedback is provided as to what will be selected: users can adjust the position of the finger, and the action takes place only when the finger is lifted off the screen. This allowed the selection of small targets, down to a single pixel on a 640×480 Video Graphics Array (VGA) screen (a standard of that time).

Sears et al. (1990)human–computer interaction of the time, describing gestures such as rotating knobs, adjusting sliders, and swiping the screen to activate a switch (or a U-shaped gesture for a toggle switch). The HCIL team developed and studied small touchscreen keyboards (including a study that showed users could type at 25 wpm on a touchscreen keyboard), aiding their introduction on mobile devices. They also designed and implemented multi-touch gestures such as selecting a range of a line, connecting objects, and a "tap-click" gesture to select while maintaining location with another finger.

In 1990, HCIL demonstrated a touchscreen slider,lock screen patent litigation between Apple and other touchscreen mobile phone vendors (in relation to

An early attempt at a handheld game console with touchscreen controls was Sega"s intended successor to the Game Gear, though the device was ultimately shelved and never released due to the expensive cost of touchscreen technology in the early 1990s.

Touchscreens would not be popularly used for video games until the release of the Nintendo DS in 2004.Apple Watch being released with a force-sensitive display in April 2015.

In 2007, 93% of touchscreens shipped were resistive and only 4% were projected capacitance. In 2013, 3% of touchscreens shipped were resistive and 90% were projected capacitance.

A resistive touchscreen panel comprises several thin layers, the most important of which are two transparent electrically resistive layers facing each other with a thin gap between. The top layer (that which is touched) has a coating on the underside surface; just beneath it is a similar resistive layer on top of its substrate. One layer has conductive connections along its sides, the other along top and bottom. A voltage is applied to one layer and sensed by the other. When an object, such as a fingertip or stylus tip, presses down onto the outer surface, the two layers touch to become connected at that point.voltage dividers, one axis at a time. By rapidly switching between each layer, the position of pressure on the screen can be detected.

Resistive touch is used in restaurants, factories and hospitals due to its high tolerance for liquids and contaminants. A major benefit of resistive-touch technology is its low cost. Additionally, as only sufficient pressure is necessary for the touch to be sensed, they may be used with gloves on, or by using anything rigid as a finger substitute. Disadvantages include the need to press down, and a risk of damage by sharp objects. Resistive touchscreens also suffer from poorer contrast, due to having additional reflections (i.e. glare) from the layers of material placed over the screen.3DS family, and the Wii U GamePad.

Surface acoustic wave (SAW) technology uses ultrasonic waves that pass over the touchscreen panel. When the panel is touched, a portion of the wave is absorbed. The change in ultrasonic waves is processed by the controller to determine the position of the touch event. Surface acoustic wave touchscreen panels can be damaged by outside elements. Contaminants on the surface can also interfere with the functionality of the touchscreen.

The Casio TC500 Capacitive touch sensor watch from 1983, with angled light exposing the touch sensor pads and traces etched onto the top watch glass surface.

A capacitive touchscreen panel consists of an insulator, such as glass, coated with a transparent conductor, such as indium tin oxide (ITO).electrostatic field, measurable as a change in capacitance. Different technologies may be used to determine the location of the touch. The location is then sent to the controller for processing. Touchscreens that use silver instead of ITO exist, as ITO causes several environmental problems due to the use of indium.complementary metal-oxide-semiconductor (CMOS) application-specific integrated circuit (ASIC) chip, which in turn usually sends the signals to a CMOS digital signal processor (DSP) for processing.

Unlike a resistive touchscreen, some capacitive touchscreens cannot be used to detect a finger through electrically insulating material, such as gloves. This disadvantage especially affects usability in consumer electronics, such as touch tablet PCs and capacitive smartphones in cold weather when people may be wearing gloves. It can be overcome with a special capacitive stylus, or a special-application glove with an embroidered patch of conductive thread allowing electrical contact with the user"s fingertip.

A low-quality switching-mode power supply unit with an accordingly unstable, noisy voltage may temporarily interfere with the precision, accuracy and sensitivity of capacitive touch screens.

Some capacitive display manufacturers continue to develop thinner and more accurate touchscreens. Those for mobile devices are now being produced with "in-cell" technology, such as in Samsung"s Super AMOLED screens, that eliminates a layer by building the capacitors inside the display itself. This type of touchscreen reduces the visible distance between the user"s finger and what the user is touching on the screen, reducing the thickness and weight of the display, which is desirable in smartphones.

In this basic technology, only one side of the insulator is coated with a conductive layer. A small voltage is applied to the layer, resulting in a uniform electrostatic field. When a conductor, such as a human finger, touches the uncoated surface, a capacitor is dynamically formed. The sensor"s controller can determine the location of the touch indirectly from the change in the capacitance as measured from the four corners of the panel. As it has no moving parts, it is moderately durable but has limited resolution, is prone to false signals from parasitic capacitive coupling, and needs calibration during manufacture. It is therefore most often used in simple applications such as industrial controls and kiosks.

This diagram shows how eight inputs to a lattice touchscreen or keypad creates 28 unique intersections, as opposed to 16 intersections created using a standard x/y multiplexed touchscreen .

Projected capacitive touch (PCT; also PCAP) technology is a variant of capacitive touch technology but where sensitivity to touch, accuracy, resolution and speed of touch have been greatly improved by the use of a simple form of

Some modern PCT touch screens are composed of thousands of discrete keys,etching a single conductive layer to form a grid pattern of electrodes, by etching two separate, perpendicular layers of conductive material with parallel lines or tracks to form a grid, or by forming an x/y grid of fine, insulation coated wires in a single layer . The number of fingers that can be detected simultaneously is determined by the number of cross-over points (x * y) . However, the number of cross-over points can be almost doubled by using a diagonal lattice layout, where, instead of x elements only ever crossing y elements, each conductive element crosses every other element .

In some designs, voltage applied to this grid creates a uniform electrostatic field, which can be measured. When a conductive object, such as a finger, comes into contact with a PCT panel, it distorts the local electrostatic field at that point. This is measurable as a change in capacitance. If a finger bridges the gap between two of the "tracks", the charge field is further interrupted and detected by the controller. The capacitance can be changed and measured at every individual point on the grid. This system is able to accurately track touches.

Unlike traditional capacitive touch technology, it is possible for a PCT system to sense a passive stylus or gloved finger. However, moisture on the surface of the panel, high humidity, or collected dust can interfere with performance.

These environmental factors, however, are not a problem with "fine wire" based touchscreens due to the fact that wire based touchscreens have a much lower "parasitic" capacitance, and there is greater distance between neighbouring conductors.

This is a common PCT approach, which makes use of the fact that most conductive objects are able to hold a charge if they are very close together. In mutual capacitive sensors, a capacitor is inherently formed by the row trace and column trace at each intersection of the grid. A 16×14 array, for example, would have 224 independent capacitors. A voltage is applied to the rows or columns. Bringing a finger or conductive stylus close to the surface of the sensor changes the local electrostatic field, which in turn reduces the mutual capacitance. The capacitance change at every individual point on the grid can be measured to accurately determine the touch location by measuring the voltage in the other axis. Mutual capacitance allows multi-touch operation where multiple fingers, palms or styli can be accurately tracked at the same time.

Self-capacitive touch screen layers are used on mobile phones such as the Sony Xperia Sola,Samsung Galaxy S4, Galaxy Note 3, Galaxy S5, and Galaxy Alpha.

Self capacitance is far more sensitive than mutual capacitance and is mainly used for single touch, simple gesturing and proximity sensing where the finger does not even have to touch the glass surface.

Capacitive touchscreens do not necessarily need to be operated by a finger, but until recently the special styli required could be quite expensive to purchase. The cost of this technology has fallen greatly in recent years and capacitive styli are now widely available for a nominal charge, and often given away free with mobile accessories. These consist of an electrically conductive shaft with a soft conductive rubber tip, thereby resistively connecting the fingers to the tip of the stylus.

Infrared sensors mounted around the display watch for a user"s touchscreen input on this PLATO V terminal in 1981. The monochromatic plasma display"s characteristic orange glow is illustrated.

An infrared touchscreen uses an array of X-Y infrared LED and photodetector pairs around the edges of the screen to detect a disruption in the pattern of LED beams. These LED beams cross each other in vertical and horizontal patterns. This helps the sensors pick up the exact location of the touch. A major benefit of such a system is that it can detect essentially any opaque object including a finger, gloved finger, stylus or pen. It is generally used in outdoor applications and POS systems that cannot rely on a conductor (such as a bare finger) to activate the touchscreen. Unlike capacitive touchscreens, infrared touchscreens do not require any patterning on the glass which increases durability and optical clarity of the overall system. Infrared touchscreens are sensitive to dirt and dust that can interfere with the infrared beams, and suffer from parallax in curved surfaces and accidental press when the user hovers a finger over the screen while searching for the item to be selected.

A translucent acrylic sheet is used as a rear-projection screen to display information. The edges of the acrylic sheet are illuminated by infrared LEDs, and infrared cameras are focused on the back of the sheet. Objects placed on the sheet are detectable by the cameras. When the sheet is touched by the user, frustrated total internal reflection results in leakage of infrared light which peaks at the points of maximum pressure, indicating the user"s touch location. Microsoft"s PixelSense tablets use this technology.

Optical touchscreens are a relatively modern development in touchscreen technology, in which two or more image sensors (such as CMOS sensors) are placed around the edges (mostly the corners) of the screen. Infrared backlights are placed in the sensor"s field of view on the opposite side of the screen. A touch blocks some lights from the sensors, and the location and size of the touching object can be calculated (see visual hull). This technology is growing in popularity due to its scalability, versatility, and affordability for larger touchscreens.

Introduced in 2002 by 3M, this system detects a touch by using sensors to measure the piezoelectricity in the glass. Complex algorithms interpret this information and provide the actual location of the touch.

The key to this technology is that a touch at any one position on the surface generates a sound wave in the substrate which then produces a unique combined signal as measured by three or more tiny transducers attached to the edges of the touchscreen. The digitized signal is compared to a list corresponding to every position on the surface, determining the touch location. A moving touch is tracked by rapid repetition of this process. Extraneous and ambient sounds are ignored since they do not match any stored sound profile. The technology differs from other sound-based technologies by using a simple look-up method rather than expensive signal-processing hardware. As with the dispersive signal technology system, a motionless finger cannot be detected after the initial touch. However, for the same reason, the touch recognition is not disrupted by any resting objects. The technology was created by SoundTouch Ltd in the early 2000s, as described by the patent family EP1852772, and introduced to the market by Tyco International"s Elo division in 2006 as Acoustic Pulse Recognition.

There are several principal ways to build a touchscreen. The key goals are to recognize one or more fingers touching a display, to interpret the command that this represents, and to communicate the command to the appropriate application.

Dispersive-signal technology measures the piezoelectric effect—the voltage generated when mechanical force is applied to a material—that occurs chemically when a strengthened glass substrate is touched.

There are two infrared-based approaches. In one, an array of sensors detects a finger touching or almost touching the display, thereby interrupting infrared light beams projected over the screen. In the other, bottom-mounted infrared cameras record heat from screen touches.

The development of multi-touch screens facilitated the tracking of more than one finger on the screen; thus, operations that require more than one finger are possible. These devices also allow multiple users to interact with the touchscreen simultaneously.

With the growing use of touchscreens, the cost of touchscreen technology is routinely absorbed into the products that incorporate it and is nearly eliminated. Touchscreen technology has demonstrated reliability and is found in airplanes, automobiles, gaming consoles, machine control systems, appliances, and handheld display devices including cellphones; the touchscreen market for mobile devices was projected to produce US$5 billion by 2009.

The ability to accurately point on the screen itself is also advancing with the emerging graphics tablet-screen hybrids. Polyvinylidene fluoride (PVDF) plays a major role in this innovation due its high piezoelectric properties, which allow the tablet to sense pressure, making such things as digital painting behave more like paper and pencil.

TapSense, announced in October 2011, allows touchscreens to distinguish what part of the hand was used for input, such as the fingertip, knuckle and fingernail. This could be used in a variety of ways, for example, to copy and paste, to capitalize letters, to activate different drawing modes, etc.

For touchscreens to be effective input devices, users must be able to accurately select targets and avoid accidental selection of adjacent targets. The design of touchscreen interfaces should reflect technical capabilities of the system, ergonomics, cognitive psychology and human physiology.

Guidelines for touchscreen designs were first developed in the 2000s, based on early research and actual use of older systems, typically using infrared grids—which were highly dependent on the size of the user"s fingers. These guidelines are less relevant for the bulk of modern touch devices which use capacitive or resistive touch technology.

Much more important is the accuracy humans have in selecting targets with their finger or a pen stylus. The accuracy of user selection varies by position on the screen: users are most accurate at the center, less so at the left and right edges, and least accurate at the top edge and especially the bottom edge. The R95 accuracy (required radius for 95% target accuracy) varies from 7 mm (0.28 in) in the center to 12 mm (0.47 in) in the lower corners.

This user inaccuracy is a result of parallax, visual acuity and the speed of the feedback loop between the eyes and fingers. The precision of the human finger alone is much, much higher than this, so when assistive technologies are provided—such as on-screen magnifiers—users can move their finger (once in contact with the screen) with precision as small as 0.1 mm (0.004 in).

Users of handheld and portable touchscreen devices hold them in a variety of ways, and routinely change their method of holding and selection to suit the position and type of input. There are four basic types of handheld interaction:

Touchscreens are often used with haptic response systems. A common example of this technology is the vibratory feedback provided when a button on the touchscreen is tapped. Haptics are used to improve the user"s experience with touchscreens by providing simulated tactile feedback, and can be designed to react immediately, partly countering on-screen response latency. Research from the University of Glasgow (Brewster, Chohan, and Brown, 2007; and more recently Hogan) demonstrates that touchscreen users reduce input errors (by 20%), increase input speed (by 20%), and lower their cognitive load (by 40%) when touchscreens are combined with haptics or tactile feedback. On top of this, a study conducted in 2013 by Boston College explored the effects that touchscreens haptic stimulation had on triggering psychological ownership of a product. Their research concluded that a touchscreens ability to incorporate high amounts of haptic involvement resulted in customers feeling more endowment to the products they were designing or buying. The study also reported that consumers using a touchscreen were willing to accept a higher price point for the items they were purchasing.

Unsupported touchscreens are still fairly common in applications such as ATMs and data kiosks, but are not an issue as the typical user only engages for brief and widely spaced periods.

Touchscreens can suffer from the problem of fingerprints on the display. This can be mitigated by the use of materials with optical coatings designed to reduce the visible effects of fingerprint oils. Most modern smartphones have oleophobic coatings, which lessen the amount of oil residue. Another option is to install a matte-finish anti-glare screen protector, which creates a slightly roughened surface that does not easily retain smudges.

Touchscreens do not work most of the time when the user wears gloves. The thickness of the glove and the material they are made of play a significant role on that and the ability of a touchscreen to pick up a touch.

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