Capacitive Touch Screen - XDA-developer encyclopedia

A capacitive touchscreen panel is coated with a material, typically indium tin oxide that conducts a continuous electrical current across the sensor. The sensor therefore exhibits a precisely controlled field of stored electrons in both the horizontal and vertical axes - it achieves capacitance. The human body is also an electrical device which has stored electrons and therefore also exhibits capacitance. When the sensor's 'normal' capacitance field (its reference state) is altered by another capacitance field, i.e., someone's finger, electronic circuits located at each corner of the panel measure the resultant 'distortion' in the sine wave characteristics of the reference field and sends the information about the event to the controller for mathematical processing. Capacitive sensors can either be touched with a bare finger or with a conductive device being held by a bare hand. Capacitive touchscreens are not affected by outside elements and have high clarity. The Apple iPhone is an example of a product that uses capacitance touchscreen technology: the iPhone is further capable of multi-touch sensing.
Capacitive sensors work based on proximity, and do not have to be directly touched to be triggered. In most cases, direct contact to a conductive metal surface does not occur and the conductive sensor is separated from the user's body by an insulating glass or plastic layer. Devices with capacitive buttons intended to be touched by a finger can often be triggered by quickly waving the palm of the hand close to the surface without touching.
The HTC/T-Mobile G1/Dream is also equipped with a capacitive touch screen.

is the Xperia X1 also equipped with Capacitive touch screen? because i noticed its not as sensitive as iphone

Without opening up the phone, there are several ways to find out if a phone uses a capacitive or resistive (i.e. pressure-sensitive) screen.
1. Look at the screen off-angle in bright light. You may be able to see a grid of dots that looks something like this and extends over the entire screen surface:
. . .
. . .
. . .
If you can, it's probably not a capacitive screen.
2. Can the screen be operated by a non-conductive object i.e. a toothpick?
If so, it's probably not a capacitive screen.
3. Does the device come with a stylus/"plectrum" and does it require screen calibration?
If it does, it's probably not a capacitive screen.
No mass-market WM device to date has a capacitive touchscreen, including the X1. The first post of this thread will help you understand why: http://discuss.pocketnow.com/showthread.php?threadid=23389

Nocturnal310 said:
is the Xperia X1 also equipped with Capacitive touch screen? because i noticed its not as sensitive as iphone
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Click to collapse
My Xperia is more sensitive than an iPhone. Granted I did some tweaking, but still.

No, Xperia is like the rest of our phones has resistive screen. It can be very sensitive, but stylus will be your main indication. I have LG Prada that has capacitive screen and LG Viewty that has a resistive one.

enigma1nz said:
No, Xperia is like the rest of our phones has resistive screen. It can be very sensitive, but stylus will be your main indication. I have LG Prada that has capacitive screen and LG Viewty that has a resistive one.
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Click to collapse
No? So, you have spied on me using my phone and know that it is not more sensitive? Pffft...

iphone rockz!
im sorry but no phone is as sensitive as an iphone!

jesse_g said:
im sorry but no phone is as sensitive as an iphone!
Click to expand...
Click to collapse
You should be sorry, because you are wrong. Do your research better and come back to apologize.

sorry but i have the same idea...... i think iPhone is more sensitive than xperia

Do capacititve screens have a separation issue like some of the HTC resistive screens have?
Where the layers of a resistive screen including the digitizer start to separate causing a rectangular shape in the center that looks like oil on water.
Has happened to me and many others where the screen eventually has a complete failure.
I do know that the capacitive screens on the iPhone are prone to breakage due to the fact that it has a glass surface.
The resistive screen of the Diamond is less prone to breakage because it has a plastic type film on the surface.
Btw, my screen is pretty sensitive, whether using the stylus or touch.

You can tweak your resistiv screen by allign screen.
If you dont press the screen and move little circles between the arrow you can make screen more sensitiv
Sorry for my english cause i am german

Black93300ZX said:
A capacitive touchscreen panel is coated with a material, typically indium tin oxide that conducts a continuous electrical current across the sensor. The sensor therefore exhibits a precisely controlled field of stored electrons in both the horizontal and vertical axes - it achieves capacitance. The human body is also an electrical device which has stored electrons and therefore also exhibits capacitance. When the sensor's 'normal' capacitance field (its reference state) is altered by another capacitance field, i.e., someone's finger, electronic circuits located at each corner of the panel measure the resultant 'distortion' in the sine wave characteristics of the reference field and sends the information about the event to the controller for mathematical processing. Capacitive sensors can either be touched with a bare finger or with a conductive device being held by a bare hand. Capacitive touchscreens are not affected by outside elements and have high clarity. The Apple iPhone is an example of a product that uses capacitance touchscreen technology: the iPhone is further capable of multi-touch sensing.
Capacitive sensors work based on proximity, and do not have to be directly touched to be triggered. In most cases, direct contact to a conductive metal surface does not occur and the conductive sensor is separated from the user's body by an insulating glass or plastic layer. Devices with capacitive buttons intended to be touched by a finger can often be triggered by quickly waving the palm of the hand close to the surface without touching.
The HTC/T-Mobile G1/Dream is also equipped with a capacitive touch screen.
Click to expand...
Click to collapse
interesting... I didn't know that

jesse_g said:
im sorry but no phone is as sensitive as an iphone!
Click to expand...
Click to collapse
darren shan said:
sorry but i have the same idea...... i think iPhone is more sensitive than xperia
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Click to collapse
Hey guys there is a cab called iTouch for blackstone and it tweaks the resistance to ultra-sensitive, works like a charm. http://forum.xda-developers.com/showthread.php?t=469865 , try it.

1. Look at the screen off-angle in bright light. You may be able to see a grid of dots that looks something like this and extends over the entire screen surface:
. . .
. . .
. . .
If you can, it's probably not a capacitive screen.
Not necessarily true. The Nexus One has a capacitive screen and also has the dots...
Sent from my Nexus One using XDA App

Multi-touch
So.. I guess I'm going to show my ignorance, but here is my question.
There are several posts on several sites talking about how you can't do multi-touch unless you have a capacitive screen. Then I go to Pandawill and look at the G10. It says it's a resistive screen but there are videos of it doing pinch-to-zoom.
Can someone help me understand how multi-touch relates to the screen type?
Sorry if i'm too much of a n00b

Sorry to add fuel to fire but a capacitive screen will always be more sensitive (speaking purely about the physics of it) than a resisitive screen.
Why?
Capacitive screens rely on charge and comparative charge of two bodies. In some instances, capacitive screens can work without the finger actually touching the screen.
Resistive screens rely on a minute deflection from contact to connect two conductive layers. You can touch a resistive screen lightly enough to not result in a UI interaction. Resisitve screens can be tweaked to work at a very high sensitivity but still not as sensitive as a capacitive screen.
Go ahead, compare two phones with opposing screen tech side by side. I thought nothing could be as responsive as my Topaz till I bought a Nexus, then Desire (which have other issues btw! )
Sorry but thats the blunt science behind it. Bear in mind the perception of responsiveness to touch can very well depend on the quality/smoothness of the software written or the user interface.
Source:
HTC Touch Diamond 2 vs. HTC Desire
Source 2:
My university degree.

Sorry for the double post but to answer your question,
Yes resistive screens can be used to provide multi touch support. Where this support isnt built into the drivers for the digitizer, its a lot harder. Bear in mind most older phones were launched before the mainstream advent of multi touch. Thus no drivers...only brilliant minds at XDA
However, using a resisitve touch screen to provide multi touch has some serious drawbacks, mainly on smaller screens.
I hate to break it to you but the reason behind this is actually the size of your "pinch" fingers with respect to screen size.
Multi touch on a small resistive screen cause deflection at multiple points on the digitizer but due to the reliance on deflection, the software will inevitably struggle to understand what sort of multitouch gesture you're trying to do! Your fingers with relation to screen size are simply too big!
When you have a bigger screen or a well designed digitizer + software, it can determine positions of multiple points much more accurately, thus allowing multi-touch.
eulalie said:
So.. I guess I'm going to show my ignorance, but here is my question.
There are several posts on several sites talking about how you can't do multi-touch unless you have a capacitive screen. Then I go to Pandawill and look at the G10. It says it's a resistive screen but there are videos of it doing pinch-to-zoom.
Can someone help me understand how multi-touch relates to the screen type?
Sorry if i'm too much of a n00b
Click to expand...
Click to collapse

ozy944 said:
Sorry for the double post but to answer your question,
Yes resistive screens can be used to provide multi touch support. Where this support isnt built into the drivers for the digitizer, its a lot harder. Bear in mind most older phones were launched before the mainstream advent of multi touch. Thus no drivers...only brilliant minds at XDA
However, using a resisitve touch screen to provide multi touch has some serious drawbacks, mainly on smaller screens.
I hate to break it to you but the reason behind this is actually the size of your "pinch" fingers with respect to screen size.
Multi touch on a small resistive screen cause deflection at multiple points on the digitizer but due to the reliance on deflection, the software will inevitably struggle to understand what sort of multitouch gesture you're trying to do! Your fingers with relation to screen size are simply too big!
When you have a bigger screen or a well designed digitizer + software, it can determine positions of multiple points much more accurately, thus allowing multi-touch.
Click to expand...
Click to collapse
Right.. I get that pinch is tougher on a small screen thats less sensative. The question was posed because there isn't a, what i consider to be cheap (in the 250$ or less range), 10 in capacative android tablet on the market.
If i venture in the the flatpad/apad/epad world... is it the case that it is impossible for that type of screen to do multi-touch? From your response I'm hearing that it IS possible to do multi-touch on a flatpad.. given that there are drivers supporting it. I'd love to have a capacative screen but from what i've seen online, they're going to be twice the cost or more.

eulalie said:
Right.. I get that pinch is tougher on a small screen thats less sensative. The question was posed because there isn't a, what i consider to be cheap (in the 250$ or less range), 10 in capacative android tablet on the market.
If i venture in the the flatpad/apad/epad world... is it the case that it is impossible for that type of screen to do multi-touch? From your response I'm hearing that it IS possible to do multi-touch on a flatpad.. given that there are drivers supporting it. I'd love to have a capacative screen but from what i've seen online, they're going to be twice the cost or more.
Click to expand...
Click to collapse
A dilemma huh? To be brutally honest, most budget oriented tablets are simply that: budget oriented. A lot of them (im trying not to generalize) and Ive tried a fair few are poorly implemented tablets and more trouble than they are worth. Slow, laggy, bad battery life. You'll have enough issues to simply forget the lack of multi touch.
If I was after a tablet, hard as it may be, Id wait till some big players launch a proper device...that'll lead to better adoption and less half baked tablets that are more tech demo than retail product.
Bear in mind the lack of android market access on almost all of these tablets. Due to their generic nature, dev work is also a no-go. Everybody and their friends and family have a device out with a costomised, baked os that its not even funny!
Id check out the galaxy tablet from samsung or wait for it to make some waves and bring forth better implemented copycat products

yodafone said:
Without opening up the phone, there are several ways to find out if a phone uses a capacitive or resistive (i.e. pressure-sensitive) screen.
1. Look at the screen off-angle in bright light. You may be able to see a grid of dots that looks something like this and extends over the entire screen surface:
. . .
. . .
. . .
If you can, it's probably not a capacitive screen.
2. Can the screen be operated by a non-conductive object i.e. a toothpick?
If so, it's probably not a capacitive screen.
3. Does the device come with a stylus/"plectrum" and does it require screen calibration?
If it does, it's probably not a capacitive screen.
No mass-market WM device to date has a capacitive touchscreen, including the X1. The first post of this thread will help you understand why: http://discuss.pocketnow.com/showthread.php?threadid=23389
Click to expand...
Click to collapse
The HTC HD2 is a capacitive touch-screen phone, was mass marketed on WM and has the dots (not horizontally but diagonally). Dont talk about it if you dont know about it.
http://crave.cnet.co.uk/mobiles/htc-hd2-first-windows-mobile-with-capacitive-touchscreen-49303837/

Related

Interesting - HD2 might not be capacitive after all

http://forum.xda-developers.com/showthread.php?t=576052
It's unlikely that HTC has completely lied in the specs, and the specs say that the screen is capacitive. However, it is like HTC to stretch the truth.
It is exceedingly unlikely that it's resistive. Resistive screens require pressure to be used - and we already know that the HD2's front is coated in glass. You can't use a resistive screen with hard glass.
As mentioned many times, the specs & hands on reviews say that the screen is capacitive! Soon we shall have the proof...
Noam23 said:
http://forum.xda-developers.com/showthread.php?t=576052
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Click to collapse
Nonsense
..
galaxys said:
As mentioned many times, the specs & hands on reviews say that the screen is capacitive! Soon we shall have the proof...
Click to expand...
Click to collapse
Yes, Till the device is not in the market we can't tell many things can change.
Noam23 said:
http://forum.xda-developers.com/showthread.php?t=576052
Click to expand...
Click to collapse
that thread sounds kinda disappointed if it is true, but I really hope it is exactly the same capacitive type of screen like iPhone and iPod Touch! The reason is, the feel between the two are really different. I personally find that resistive screen has a cheap feeling to me as it has a soft thin layer on top with visible dots, and the gap between the layer can feel very easily. However, true capacitive screen feels like it is entirely glass top, it is very solid and handling the device with the screen is a joy. Just a tiny touch of the screen will have instant response from capacity screen, so, I personally prefer iPhone capacitive screen, and I really hope this is not true!!!!!!!!!!!!
wonsanim said:
Yes, Till the device is not in the market we can't tell many things can change.
Click to expand...
Click to collapse
That's right...
From HTC's website: The world’s first capacitive touch technology on a Windows® phone
Works for me.
precsmo said:
I personally find that resistive screen has a cheap feeling to me as it has a soft thin layer on top with visible dots, and the gap between the layer can feel very easily. However, true capacitive screen feels like it is entirely glass top, it is very solid and handling the device with the screen is a joy.
Click to expand...
Click to collapse
Then you have never seen true capacitive screens. They have a layer of conductive wires just behind the glass top. On the 40 inch capacitive screen I use, you can clearly see them even at maximum brightness.
I've seen the dots on blackberry storm too, I've got Pre and once i've notice too, but both of the screen made of hard glass and very bright.
They both are capacitive screens.
Gloves
Dark Fire said:
It's unlikely that HTC has completely lied in the specs, and the specs say that the screen is capacitive. However, it is like HTC to stretch the truth.
Click to expand...
Click to collapse
Whatever the screen is, I just need it to be glove-compatible, just like the Omnia, Omnia 2, Blackstone but UNLIKE iPod Touch (which i have), and iPhone. How do you communicate in winter with a full touch screen, and with wm 6.5.1 which might not allow answering with the hard "answer" button? My Omnia 2 is out of order: the antenna is broken(?) anyway i don't have any network reception. When it comes back from servicing in 2-3 weeks, I just sell it and buy a HD2.
forelli
forelli said:
Whatever the screen is, I just need it to be glove-compatible, just like the Omnia, Omnia 2, Blackstone but UNLIKE iPod Touch (which i have), and iPhone. How do you communicate in winter with a full touch screen, and with wm 6.5.1 which might not allow answering with the hard "answer" button? My Omnia 2 is out of order: the antenna is broken(?) anyway i don't have any network reception. When it comes back from servicing in 2-3 weeks, I just sell it and buy a HD2.
forelli
Click to expand...
Click to collapse
it's never going to be 'glove compatible' you need to touch the screen with a conductive item..ie your hand, metal stylus etc. a glove will not work
forelli said:
Whatever the screen is, I just need it to be glove-compatible, just like the Omnia, Omnia 2, Blackstone but UNLIKE iPod Touch (which i have), and iPhone. How do you communicate in winter with a full touch screen, and with wm 6.5.1 which might not allow answering with the hard "answer" button? My Omnia 2 is out of order: the antenna is broken(?) anyway i don't have any network reception. When it comes back from servicing in 2-3 weeks, I just sell it and buy a HD2.
forelli
Click to expand...
Click to collapse
I started thinking about the same thing today since I live in sweden, and came up with the solution:
use your nose! its gonna look funny as hell, but I aint taking my gloves of when the winter hits hard
shame
twisted-pixel said:
it's never going to be 'glove compatible' you need to touch the screen with a conductive item..ie your hand, metal stylus etc. a glove will not work
Click to expand...
Click to collapse
Thnaks for the answer. what a pity: i think the blackstone with 1 Ghz Snapdragon is the best alternative, or the Omnia 2 and its 800 Mhz cpu with a more comprehensive GUI and a bigger screen...
forelli said:
... blackstone with 1 Ghz Snapdragon is the best alternative...
Click to expand...
Click to collapse
It's called the Acer NeoTouch (F1)
TrYde said:
Then you have never seen true capacitive screens. They have a layer of conductive wires just behind the glass top. On the 40 inch capacitive screen I use, you can clearly see them even at maximum brightness.
Click to expand...
Click to collapse
even if it is true, but it is 4.3" vs 40", it is way too far to compare and if the 4.3" can ever notice the wires? At least iPhone look like just one whole piece of solid glass touch screen, and that is what I prefer

What are capacitive screens really good for?

First things first: I generally like my HD2 - It's fast, has a nice display and a lot of other nice features but the touch screen outright sucks and is bordering on useless. Of course the iphone screen isn't much better but it still beats the HD2 screen hands down.
What's all the fuss about capacitive screens? All I can see is a loss in functionality. I hear their more durable but who cares whether the screen lasts 3 years or 10???? It's nowhere near as precise as any other touch screen device I ever owned. I can't use a stylus for drawing small things or playing most games....try playing crayon physics with this absolute piece of junk...or Warfare Incorporated.
I installed a sensitivity fix cab and it's somewhat usable for day to day stuff but still.....the 4.3" screen is nowhere near as usable as the 3" my X1 had and I could operate that with my finger only quite all right.
Seems like there nothing in capacitive screens other than being iphone-like. Why not have a 4.3" resistive screen? What's the actual downside?
ewok666 said:
try playing crayon physics
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Click to collapse
I am and it works just fine for me
There are styluses (styli?) available for cap. screens also though.
The advantige of capacitive touch screens:
Glass can be used. Less vulnerable.
multi touch can be implemented.
more touch sensetive.
The advantige of resistive touch screens:
more accurate without software.
simple styles can be used.
cheap.
greatings,
marc
ewok666 said:
I can't use a stylus for drawing small things or playing most games....try playing crayon physics with this absolute piece of junk...or Warfare Incorporated.
Click to expand...
Click to collapse
Get ready to be flamed for your attitude. Coming onto a forum for fans of a device and calling it an "absolute piece of junk" is a pretty good way to not make friends!
Anyway, I finished Crayon Physics the other day, and had no problems doing so with my fingers. I suggest that the hardware isn't the problem here. Everyone else seems to manage fine.
I'd say the biggest downside of capacitive screens is the absence of multitouch capabilities. I have absolutely no problems operating my phone with it's capacitive screen. So to speak, Windows Mobile 6.x.x isn't really optimized for it anyways, as the HD2 was the first phone with capacitive screen on the platform.
If you wanted to work precise with a stylus then maybe you shouldn't have bought an HD2 in the first place.
ewok666 said:
... try playing crayon physics with this absolute piece of junk
Click to expand...
Click to collapse
No offence but I would say that not being able to play/finish crayon physics deluxe with this peace of jewellery is of course not caused by the screen or the phone. I would search the cause somewhere else.....
ewok666 said:
First things first: I generally like my HD2 - It's fast, has a nice display and a lot of other nice features but the touch screen outright sucks and is bordering on useless. Of course the iphone screen isn't much better but it still beats the HD2 screen hands down.
What's all the fuss about capacitive screens? All I can see is a loss in functionality. I hear their more durable but who cares whether the screen lasts 3 years or 10???? It's nowhere near as precise as any other touch screen device I ever owned. I can't use a stylus for drawing small things or playing most games....try playing crayon physics with this absolute piece of junk...or Warfare Incorporated.
I installed a sensitivity fix cab and it's somewhat usable for day to day stuff but still.....the 4.3" screen is nowhere near as usable as the 3" my X1 had and I could operate that with my finger only quite all right.
Seems like there nothing in capacitive screens other than being iphone-like. Why not have a 4.3" resistive screen? What's the actual downside?
Click to expand...
Click to collapse
The whole benefit of a capacitive screen for me is that I don't have to use a stylus. If I wanted to use a stylus I would have gone for a different phone.
Why did you buy this phone if you wanted to use a stylus? You can however get one, have you tried that first before falling out with the phone? It could fulfill all your needs and then you'll see how good the HD2 is.
I think that it is a matter of habit and getting used to resistive screens in your case. I havent had a resistive screen ever but i played a quite a lot with some and i must say that capacitive is much more interactive, finger friendly and intuitive than resistive so you might just try not to be so stuborn and give it a chance Everytime i try to do something with my girlfriends' resistive samsung and i keep getting stuck with not knowing how hard should I push the screen exactly ... I am not a fan of the resistive and after all it is called TOUCH screen not a Push screen Enjoy your Hd mate !
You can use fingers on resistive touchscreens. These days even resistive touchscreens can have multitouch.
I think the main advantage of capacitive screen is the glass, as was mentioned. Resistive screen must deform under the touching object, which means it wears down.
For phone, capacitive screen is just ok.
For tablet PCs, I'd like to see combination of capacitive screen with electromagnetic stylus (like tablet has) where you could switch the mode.
Capacitive screen is good for fast controls, but if you draw with stylus, you don't want the screen to react on random touches.
For example iPad has rather thick borders around the screen .. because you have to hold it somehow without actually touching the screen.
ewok666 said:
try playing crayon physics with this absolute piece of junk
Click to expand...
Click to collapse
The game is so addictive i completed this morning. Try junking your fingers?
A capacitive screen makes our screen a real touch screen instead of 'tap screen'.
kruithofm said:
The advantige of capacitive touch screens:
more touch sensetive.
Click to expand...
Click to collapse
I don't think so. Resistive is much more sensitive and precise. Pen stroke input used to be the reason PPC stuck to resistive input.
Being an HD2 fan doesn't mean a capacitive fan. Capacitive is the reason that I nearly bought an Omnia II instead of HD2. For me, it is something to hate.
With resistive, I don't mind carrying around a stylus when it means I can do precision work. And I can still use my fingers when I need to.
Now that we have WVGA, I believe now that we can sacrifice screen estate and use huge UIs so that capacitive screen can survive. But that means old applications written for resistive screens (including WM6.1 dialogues) usually have too small UIs for use on HD2.
Alex, That the Capacitive touch is more sensetive is an advantige, with the interface or software you can decrese the sensetivety. On resistive touch screens it is technicaly inposible to get the sensetivety as high as on capacitive.
It is posible to make resistive touch screens multitouch. only that takes a lot of software to calculate positions of pressing.
The techniek is very different between both. therefore you love it or you don't. some get used to it, some don't. It is all personal. There are even people who love the small keyboards. And even my wife loves only the number keys on the normal simple phones since she uses the dictionairy. And I have to say, She is faster writing a sms than me.
So everyone should use whatever they like. Every option has it's advantiges.
johncmolyneux said:
Get ready to be flamed for your attitude. Coming onto a forum for fans of a device and calling it an "absolute piece of junk" is a pretty good way to not make friends!
Anyway, I finished Crayon Physics the other day, and had no problems doing so with my fingers. I suggest that the hardware isn't the problem here. Everyone else seems to manage fine.
Click to expand...
Click to collapse
I should have been more specific: The junk I'm referring to is the screen and NOT the device. Like I said, I like the device but IMHO all the 'advantages' of capacitive don't make up for its downsides.
Just to address some of the comments:
Resistive screens CAN be touch operated without a stylus
They do NOT break down all the time
AFAIK they CAN support multitouch
Maybe it's just the crappy implementation of capacitive that HTC has done. The Iphone screen does not seem to suffer from all the issues the HD2 has:
http://forum.xda-developers.com/showthread.php?t=595655
http://forum.xda-developers.com/showthread.php?t=604831
The stylus for capacitive screens is a joke. Come on, do they have to be that fat and ugly? Is there really no way to have a small, pointy, conductive stylus?
Are capacitive screen really a requirement for WM7?
ewok666 said:
The stylus for capacitive screens is a joke. Come on, do they have to be that fat and ugly? Is there really no way to have a small, pointy, conductive stylus?
Click to expand...
Click to collapse
Learn before you preach.
johncmolyneux said:
Get ready to be flamed for your attitude. Coming onto a forum for fans of a device and calling it an "absolute piece of junk" is a pretty good way to not make friends!
Anyway, I finished Crayon Physics the other day, and had no problems doing so with my fingers. I suggest that the hardware isn't the problem here. Everyone else seems to manage fine.
Click to expand...
Click to collapse
Hahahahahaha!!! John is right. Better be careful what you post on this forum.
I say put your fingers on a strict diet! Enroll them in a exercise regime until you can use your "piece of junk" effectively.
Well, for me the #1 reason for me to get an HD2 IS the capacitive screen.
I've had many many resistive screen devices (1 old pocketpc, 4 HTC phones, 2 touch-enabled UMPCs), and I'm tired of having to use my nail to press on that screen. It's perfectly fine on old-style UIs that rely on clicks only, but for the "new" flick, scroll, tap, pinch, rotate, capacitive is just the way to go.
Still getting mad when I tap my Kaiser's screen with my finger (not the nail) and it thinks I want to scroll, and goes 2 pages down... only works fine with something sharp, whatever the settings/tweaks.
capacitive is a reason to buy for me: it is what made the HD2 stand out for me. I will never go back to resistive technology.
I must say though that in my opinion the iPhone display is of a superior quality, not in terms of pixel count, but certainly in terms of its accuracy, sensitivity and reliability. it is simply a lot easier to tap out words on the iPhone than on the HD2. It also responds better to cold (if I go out in the winter breeze I sometimes find my HD2 starts pressing keys and moving the screen about of its own accord).
ewok666 said:
I should have been more specific: The junk I'm referring to is the screen and NOT the device. Like I said, I like the device but IMHO all the 'advantages' of capacitive don't make up for its downsides.
Just to address some of the comments:
Resistive screens CAN be touch operated without a stylus
They do NOT break down all the time
AFAIK they CAN support multitouch
Maybe it's just the crappy implementation of capacitive that HTC has done. The Iphone screen does not seem to suffer from all the issues the HD2 has:
http://forum.xda-developers.com/showthread.php?t=595655
http://forum.xda-developers.com/showthread.php?t=604831
The stylus for capacitive screens is a joke. Come on, do they have to be that fat and ugly? Is there really no way to have a small, pointy, conductive stylus?
Are capacitive screen really a requirement for WM7?
Click to expand...
Click to collapse
try walkin down the street while tryin to send an sms using the stylus on a resistive screen...u'll be sooo glad ur hd2 is capacitive...
kruithofm said:
The advantige of capacitive touch screens:
Glass can be used. Less vulnerable.
multi touch can be implemented.
more touch sensetive.
The advantige of resistive touch screens:
more accurate without software.
simple styles can be used.
cheap.
greatings,
marc
Click to expand...
Click to collapse
this should have been end of thread.

My Research Into HD2 Android Touchscreen issues

hey guys
ive noticed that a thew of you are having issues with the touchscreen,particularly when running recent roms
now ive been having a look and have come up with an idea to resolve this problem,first we have to understand the screen,our lovely HD2 has a multi touch TFT capacitive touchscreen, 65K colors 480 x 800 pixels, 4.3 inches WVGA
now about multi touch capacitive touch screen from wiki as bellow:
Multi-touch has been implemented in several different ways, depending on the size and type of interface. Both touchtables and touch walls project an image through acrylic or glass, and then back-light the image with LEDs. When a finger or an object touches the surface, causing the light to scatter, the reflection is caught with sensors or cameras that send the data to software which dictates response to the touch, depending on the type of reflection measured. Touch surfaces can also be made pressure-sensitive by the addition of a pressure-sensitive coating that flexes differently depending on how firmly it is pressed, altering the reflection.[2] Handheld technologies use a panel that carries an electrical charge. When a finger touches the screen, the touch disrupts the panel's electrical field. The disruption is registered and sent to the software, which then initiates a response to the gesture.
if you get what that means then we'll move on.Now then most of the builds weve been using are designed for either AMOLED/LCD capacitive touchscreen at16M colors so in basic terms when we touch our screens it sends a signal to the software saying youve touched only the software thinks were all using 16M capacitive touchscreen when in actual fact were only using 65k capacitive touchscreens thus eventually causing lack of responce,so whats the solution i hear you cry,well we have to look at our beloved friend the evo 4G wich has the same screen TFT capacitive touchscreen, 65K colors so we have use the files/script/value or whatever devs use to controll the display and touchscreen from the 4g and use them in HD2 android builds this way we shouldnt be able to wear out our touchscreens in android builds,something for Devs to do and we already have Evo ports,probably explains why no one or heard of has had this problem when running Evo builds.Does that Make sence
The LCD screen and the digitizer are 2 separate components. The touchscreen itself has nothing to do with colors.
Seriously when can we just stop the bullshiting about stuff YOU clearly dont understand ?
The last few weeks there has been a huge spike in stupid topics from ppl trying to convince other ppl to also be stupid.
shuntje said:
Seriously when can we just stop the bullshiting about stuff clearly dont understand ?
The last few weeks there has been a huge spike in stupid topics from ppl trying to convince other ppl to also be stupid.
Click to expand...
Click to collapse
Best. Post. Ever.
IphoneKiller125 said:
hey guys
ive noticed that a thew of you are having issues with the touchscreen,particularly when running recent roms
now ive been having a look and have come up with an idea to resolve this problem,first we have to understand the screen,our lovely HD2 has a multi touch TFT capacitive touchscreen, 65K colors 480 x 800 pixels, 4.3 inches WVGA
now about multi touch capacitive touch screen from wiki as bellow:
Multi-touch has been implemented in several different ways, depending on the size and type of interface. Both touchtables and touch walls project an image through acrylic or glass, and then back-light the image with LEDs. When a finger or an object touches the surface, causing the light to scatter, the reflection is caught with sensors or cameras that send the data to software which dictates response to the touch, depending on the type of reflection measured. Touch surfaces can also be made pressure-sensitive by the addition of a pressure-sensitive coating that flexes differently depending on how firmly it is pressed, altering the reflection.[2] Handheld technologies use a panel that carries an electrical charge. When a finger touches the screen, the touch disrupts the panel's electrical field. The disruption is registered and sent to the software, which then initiates a response to the gesture.
if you get what that means then we'll move on.Now then most of the builds weve been using are designed for either AMOLED/LCD capacitive touchscreen at16M colors so in basic terms when we touch our screens it sends a signal to the software saying youve touched only the software thinks were all using 16M capacitive touchscreen when in actual fact were only using 65k capacitive touchscreens thus eventually causing lack of responce,so whats the solution i hear you cry,well we have to look at our beloved friend the evo 4G wich has the same screen TFT capacitive touchscreen, 65K colors so we have use the files/script/value or whatever devs use to controll the display and touchscreen from the 4g and use them in HD2 android builds this way we shouldnt be able to wear out our touchscreens in android builds,something for Devs to do and we already have Evo ports,probably explains why no one or heard of has had this problem when running Evo builds.Does that Make sence
Click to expand...
Click to collapse
lol worst research ever
I'm wondering what was your reasearch methode ?
Becouse all you found was information about the screen and nothing about the actual module for the toutch screen.
shuntje said:
I'm wondering what was your reasearch methode ?
Becouse all you found was information about the screen and nothing about the actual module for the toutch screen.
Click to expand...
Click to collapse
Well i assumed you guys knew that the HD2 has an LCM module wich is shown here
Uploaded with ImageShack.us
it combines the digitizer,backlight,Lcd so it conects to the main board from the same port for easer installation.Now the point im trying to get across is that weve been using builds that use AMOLED,AMOLED displays have an integrated touch function.AMOLED screens that htc use are made by Samsung wich has placed a touch-sensor (on-cell) over the display. The thickness of the touch sensor is very thin and this allows the screen to provide better images and to have great visibility even in direct sunlight and are very responsive to touch,Now becouse we havnt got these screens the builds,in particular with desire builds it is making our screens work overtime and this can create dead spots or areas of the screen that do not respond accurately to touch wich can be caused by a conflict in the software/firmware or it could be that the LCM causes problems in the software wich then makes it unresponsive http://www.htcphones.net/htc-hd2-problems-with-touchscreen/ or then again it could be this http://wmpoweruser.com/strange-htc-hd2-touch-screen-behaviour-is-your-device-affected/ there are several possibillty,unfortunently each phone is unique
I have trouble deciding whether you are a troll or a retard.
Neither of those possibilities are very attractive though.
The only problem HD2 has with multitouch is that It cant handle two inputs in the same vertical line. you will see if you test it with Multitouch visibility test. Also in air hockey 2 player mode you will see the same effect. If the two points are in the same vertical point it will jump.
Builds and kernels are indeed different... a build for an amoled phone can work with no problem on our hd2
It doesn't matter; we have our own special panel and ts drivers in the kernel. (board-htcleo-ts.c and board-htcleo-panel.c)
Damm Straight Best Post Ever!
This is simply THE most hilarious post I've read on here!!
I've never seen a post with such bull****. Clearly the OP hasn't got a clue what he's talking about.
I am lost for words
Now that we have a THANKS button, we also need a BULL**** button, everyone with a brain who reads this thread would be frantically clicking away on it!!
..........
IphoneKiller125 said:
Well i assumed you guys knew that the HD2 has an LCM module wich is shown here
Uploaded with ImageShack.us
it combines the digitizer,backlight,Lcd so it conects to the main board from the same port for easer installation.Now the point im trying to get across is that weve been using builds that use AMOLED,AMOLED displays have an integrated touch function.AMOLED screens that htc use are made by Samsung wich has placed a touch-sensor (on-cell) over the display. The thickness of the touch sensor is very thin and this allows the screen to provide better images and to have great visibility even in direct sunlight and are very responsive to touch,Now becouse we havnt got these screens the builds,in particular with desire builds it is making our screens work overtime and this can create dead spots or areas of the screen that do not respond accurately to touch wich can be caused by a conflict in the software/firmware or it could be that the LCM causes problems in the software wich then makes it unresponsive http://www.htcphones.net/htc-hd2-problems-with-touchscreen/ or then again it could be this http://wmpoweruser.com/strange-htc-hd2-touch-screen-behaviour-is-your-device-affected/ there are several possibillty,unfortunently each phone is unique
Click to expand...
Click to collapse
Dude ok break down of how i undertand the phone works between kernel and hardware
The kernel accesses a chip with a unified and commonly accepted standard of IO. Then the hardware specific chip (the Toutch screen controller or what not) makes this into readeble data and vise versa. This way there is NO WAY IN HELL it can break the actual hardware. If your screen is breaking down bad luck i had a HD2 with a defect TS in the first week. A mate of mine had one within the first ****ing day. Its random stop feeding yourself with bull**** and go back to the tinfoil hat forums.
deffo has the lol factor
shuntje said:
Dude ok break down of how i undertand the phone works between kernal and hardware
The kernal accesses a chip with a unified and commonly accepted standard of IO. Then the hardware specific chip (the Toutch screen controller or what not) makes this into readeble data and vise versa. This way there is NO WAY IN HELL it can break the actual hardware. If your screen is breaking down bad luck i had a HD2 with a defect TS in the first week. A mate of mine had one within the first ****ing day. Its random stop feeding yourself with bull**** and go back to the tinfoil hat forums.
Click to expand...
Click to collapse
Actually since the kernel (please, not kernal) interacts with the hardware directly it can damage it permanently. For example, supply too much voltage to the cpu and you fry it, use the touchscreen with incorrect calibration settings for extended periods of time and you can also damage it. However, there are no cases of the Leo Android TS driver breaking touchscreens.
Where are the naked pics? Someone said there were naked pics in this thread.
OHHHHH another "whine, Android, whine, messed up, whine, my touchscreen, whine" thread.
...dissappointingly clicks the back button
I have some cellophane I stole from a cigarette packet. I was wondering, as the size is similar to my HD2, are they compatible models? I was thinking of replacing the touchscreen with it.
Sorry to take this thread in a new direction but it seemed the appropriate place to ask.
harpss1ngh said:
Now that we have a THANKS button, we also need a BULL**** button...
Click to expand...
Click to collapse
Made my day

[Q] Is it possible getting multi touch?

I know the LG Optimus has a resistive touch screen, but is it possible to get muti touch by replacing original touchscreen to a glass touch screen and a new digitizer?
I cannot say it is impossible, because everything is possible. I think it is not worth
That's quite a big question, one problem that stands out is the odd shape of the GT540's screen, it doesn't stop as such where the screen stops, it stops before the real buttons, that would suggest to me that you'd have to have a custom screen and digitizer with those resistive buttons we have at the bottom (MENU, BACK) changed to capacitive, a custom screen would probably cost more than the phone itself. But if you do decide to waste a load of money outfitting a phone instead of buying a new one, on top of that you'd have to be able to program drivers for the display to work and you would have to modify your software that your phone runs top work with multi-touch.
So in short, really, no.
But if we had a load of developers (which we don't) what could be designed is a counter-point which isn't multi-touch in the traditional sense and is a software work-around, but still a bit of a waste of time.
I think is very strong to realize.
But i should be wonder
It's a very hard work... I don't think we'll have multitouch soon...
i will really want multitouch but think about it, its just cheaper and less time consuming to just get a new phone..
I am not permitted to post links, so search on youtube ''lg gt540 multi touch'' (without the quotes). First result is the one.
about the video:
This guy made a workaround for basic dualtouch. AFAIK and see one finger needs to be hold in place.
HI MrAndroid12
I think it's possible only if some one tweaks the kernel for recognizing multiple points
after replacing the resistive touch screen to capacitive one...
I would like to clear one thing to everyone who have an wrong notion about resistive touch screen..
A resistive touch screen can recognize a stylus or a small area of touch well
but a capacitive screen can recognize a larger area of touch like a finger..
and some resistive screen devices can multi touch..
Thanks are welcome if you found this post useful... Mail me for more details
subham964 said:
and some resistive screen devices can multi touch..
Click to expand...
Click to collapse
Which?
Sent from my GT540 using XDA App
Resisitive
This phone has a RESISTIVE touch screen:
http://www.gsmarena.com/multitouch_coming_to_for_nokia_5800_xpressmusic_sort_of-news-872.php
subham964 said:
HI MrAndroid12
I would like to clear one thing to everyone who have an wrong notion about resistive touch screen..
A resistive touch screen can recognize a stylus or a small area of touch well
but a capacitive screen can recognize a larger area of touch like a finger..
and some resistive screen devices can multi touch..
Thanks are welcome if you found this post useful... Mail me for more details
Click to expand...
Click to collapse
Our GT540 has a really qualitative resistive screen, compared with others. And, yes, I really like using a stylus, for handwritten notes for example (I still miss my LG Cookie for that function).
It's true that capacitive screens have been advertized as better than resistive.
It is true,if you like responsiveness and the highest standards of all have been set by Apple in this field.
However, it is not ONLY responsiveness that matters in some cases, right?
It would be good if LG did
make lg gt540 multi-touch!!
sad...
Another issue to be aware of is the electronics to drive a capacitative screen are different to those for a resistive one. I think a lot more work would be involved beyond just drivers and actually finding a screen that would work.
androidboss7 said:
It would be good if LG did
make lg gt540 multi-touch!!
sad...
Click to expand...
Click to collapse
Can't agree more. I just can't wait for my next phone
it's possible.. but it's very expensive..

[Q] Touch sensitivity affected by anti glare screen protector?

Does anyone know if the use of an anti glare screen protector or any screen protector for that matter would affect touch sensitivity of the Nexus 7? I'm currently using an anti glare screen protector for the Galaxy Tab (2) 10.1 which I trimmed down for temporary use with the Nexus 7 until the ones I ordered online arrive.
However, I notice that whenever I'm doing things such as rapidly scrolling through lists, the kinetic scrolling will suddenly stop every once in a while. This also occasionally happens with the notification center, where I'm in the middle of pulling down the notification bar and it acts as though my finger only pulled it down part way, which either results in the notification bar to retract back to the top of the screen or to fall open on its own without the use of my finger.
Does anyone know if using a screen protector would cause problems with touch screen sensitivity? I have qualms about returning this or exchanging it as it's the 3rd one I have gotten and it has no other problems as far as I can tell.
Tl;dr ver: Do screen protectors affect touch screen sensitivity?
Sent from my Nexus 7 using Tapatalk 2
As distance increases the capacitance effectively decreases, yes. So the thicker the material layers are between your fingertip and the underlying sensor the less responsive (or less sensitive) the sensing becomes. This correlation occurs on a logarithmic scale and most devices I've looked at spec out at about 6mm - where 6mm of material effectively inhibits sensing completely. Most phone screens that's I've been able to investigate have about 0.6mm to 0.8mm of material already. I don't know what the thickness of the typical protector sheets are but even if yours is 1mm thick (which would be very thick actually!) it shouldn't effect touch registrations by very much. A little bit yes, but I guess it wouldn't be noticeable in practice.
Of course the easy way to find out is to turn on the touch indicators if your phone/kernel support it and try it both with and without the protector in place.
One way to increase touch sensitivity with your device is to increase your iron intake. Iron tablets are cheap and good for you. Make SURE you follow any dosage instructions on the label as iron is one of those minerals which can cause problems if you over dose yourself.
Bifurcator said:
As distance increases the capacitance effectively decreases, yes. So the thicker the material layers are between your fingertip and the underlying sensor the less responsive (or less sensitive) the sensing becomes. This correlation occurs on a logarithmic scale and most devices I've looked at spec out at about 6mm - where 6mm of material effectively inhibits sensing completely. Most phone screens that's I've been able to investigate have about 0.6mm to 0.8mm of material already. I don't know what the thickness of the typical protector sheets are but even if your is 1mm thick (which would be very thick actually!) it shouldn't effect touch registrations by very much. A little bit yes, but I guess it wouldn't be noticeable in practice.
Of course the easy way to find out is to turn on the touch indicators if your phone/kernel support it and try it both with and without the protector in place.
Click to expand...
Click to collapse
That sounds like a pretty good amount of knowledge you have on screen protectors. Although, I wonder if it is also a possibility that the screen itself is flawed. I often find myself testing the touch screen with multi touch apps and I can never see any point where the screen will not register a touch. It also doesn't seem to be software based either it occurred on stock as well as CM10.
Sent from my Nexus 7 using Tapatalk 2
I of course wouldn't know if your sensor was defective or not. But the design is extremely simple and the way they work would imply that if it worked in one area of the screen it will work across the entire screen given that the relative dielectric constant is even throughout the material volume. And if it wasn't you would likely see it as thousands of micro-bubbles, cracks, or other aberrations.
Also keep in mind that temperature and humidity have affect as well.
Bifurcator said:
I of course wouldn't know if your sensor was defective or not. But the design is extremely simple and the way they work would imply that if it worked in one area of the screen it will work across the entire screen given that the relative dielectric constant is even throughout the material volume. And if it wasn't you would likely see it as thousands of micro-bubbles, cracks, or other aberrations.
Also keep in mind that temperature and humidity have affect as well.
Click to expand...
Click to collapse
Thanks for the explanations. Looks like I'll spend a few days experimenting with and without a a screen protector in order to deduct if the screen protector is at fault or if it is a defect within the product.
Sent from my Nexus 7 using Tapatalk 2
MidnightXZ said:
Thanks for the explanations. Looks like I'll spend a few days experimenting with and without a a screen protector in order to deduct if the screen protector is at fault or if it is a defect within the product.
Click to expand...
Click to collapse
NP, you're welcome. And take some iron tablets!
Bifurcator said:
NP, you're welcome. And take some iron tablets!
Click to expand...
Click to collapse
Iron tablets? Do they increase my ability to interact with a capacitive touch screen or something? xD
Sent from my Nexus 7 using Tapatalk 2
MidnightXZ said:
Iron tablets? Do they increase my ability to interact with a capacitive touch screen or something? xD
Click to expand...
Click to collapse
Yep! The difference between a person with an iron deficiency and someone with a goodly amount can be enormous. In typical variations (say a poor iron intake in the diet compounded by a blood donation or menstruation as opposed to a person eating right and supplementing) can be over two times in terms of touch sensitivity.
If there's zero iron in your blood (besides being in danger of immediate death from organ failure.. ) your touch screen will not be able to detect you at all. The iron in an individual's blood creates strings of capacitors between every epidermal surface of the body. When someone creates a capacitance by touching (or actually even moving into proximity) of the sensor's conductor it creates a capacitance (essentially coupling to ground) by adding a second capacitance (you) in parallel to the sensor's capacitance. When such a ground is introduced the charge-time (frequency) of the sensor slows way down and a "touch" is registered. This is the basic premiss (in brief!) behind Capacitive Touch Sensing (CTS). There's other things going on as well depending on the type of touch screen but almost all of them (found in cell phones) depend on this basic principal.
Fun facts aye? LOL
Bifurcator said:
Yep! The difference between a person with an iron deficiency and someone with a goodly amount can be enormous. In typical variations (say a poor iron intake in the diet compounded by a blood donation or menstruation as opposed to a person eating right and supplementing) can be over two times in terms of touch sensitivity.
If there's zero iron in your blood (besides being in danger of immediate death from organ failure.. ) your touch screen will not be able to detect you at all. The iron in an individual's blood creates strings of capacitors between every epidermal surface of the body. When someone creates a capacitance by touching (or actually even moving into proximity) of the sensor's conductor it creates a capacitance (essentially coupling to ground) by adding a second capacitance (you) in parallel to the sensor's capacitance. This is the basic premiss (in brief!) behind Capacitive Touch Sensing (CTS). There's other things going on as well depending on the type of touch screen but almost all of them (found in cell phones) depend on this basic principal.
Fun facts aye? LOL
Click to expand...
Click to collapse
Very fun indeed. xD
I had problems with 2 different screen films. One was a iPad one trimmed down to fit the other a nexus 7 one ordered online. Both seemed OK for one or two touches but lost all when I tried some games, like bad piggies and plants vs zombies. Had to take them off .
Sent from my Nexus 7 using xda app-developers app
Yeah, it certainly is possible. It sounds like the nexus 7's sensor may be a bit on the weak side just from reading here.
<shrug>
Bifurcator said:
Yeah, it certainly is possible. It sounds like the nexus 7's sensor may be a bit on the weak side just from reading here.
<shrug>
Click to expand...
Click to collapse
My first Nexus 7 had no problems with an anti glare screen protector although it did have screen lift albeit, that screen protector was designed for it. 2nd was replaced within 5 minutes if purchasing. 3rd and current one seem to have intermittent touch issues when swiping. Although I have yet to determine if the cause is the screen protector or the device itself.
Sent from my Nexus 7 using Tapatalk 2
Any progress?
I think it's almost impossible for it to be the fault of the screen protector. But there are many kinds of touch screens and if the Nexus7 just happens to be using some hybrid that needs pressure then it's certainly possible.
Think of CTS screens (almost) as proximity sensors. They can actually sense (you) from around a foot away quite easily. As the distance decreases the "signal strength" increases. If we apply an arbitrary numerical value to that signal strength it /might/ look something like:
9 inches - 0.01
8 inches - 0.02
7 inches - 0.02
6 inches - 0.03
5 inches - 0.04
4 inches - 0.05
3 inches - 0.07
2 inches - 0.10
1 inches - 0.20
0.1 inches - 1.00
0.001 inches - 2.00
0" full contact - 10.00
But typically the software algorithms which determine whether a touch event has occurred or not imply a threshold value of (again arbitrary for the sake of example), 9.00. The dielectric properties of "the" plastics of interest for protectors and screens have been thoroughly examined and established AFAIK. They do disperse the electrical force somewhat via factors such as air-space between the protector layer and the screen, whatever insulating impurities may be present in the protector material, the material's own molecular structure, and etc. The amount of electrical field dispersion or distortion that occurs through the material is a function of the materials thickness in the case of the materials commonly being used. Maybe you can imagine looking at a flashlight through murky/milky water where the closer you get the stronger the signal and the more clarity (of the source) can be distinguished. Where this "strength/clarity" begins to become a problem for software "touch" detection is usually around 5mm or 6mm (of commonly used material) between your fingertip and the sensor. If different materials are used this distance changes and can change radically. In keeping with my photovoltaic example, if the material in question could act like a tight bundle of optical fibers (only of course conducting electricity and not light) then the "protective" material could be meters thick without being detrimental to the registration of a touch event.
This is why i think it's almost impossible for it to be the fault of the protector... But everything factor's in. Body weight, blood iron content, protector material impurities, humidity (RH), temperature, skin moisture, variations in the Earth's electrical field from area to area and over time, material thickness, the software algorithm's threshold values, and so on. If they all come together in just the wrong way you could experience the touch registration intermittence you are describing - for sure. And with millions and millions of sensor screens being manufactured it could also be faulty connections there too but /that/ would be my very last guess as they really are ultra-simply constructed. If it's charging at all it should (famous last words) work equally across the entire surface area.
---------- Post added at 01:20 AM ---------- Previous post was at 12:58 AM ----------
Have a look at that poll thread tho:
http://forum.xda-developers.com/poll.php?do=showresults&pollid=9771
416 people report screen separation and almost 130 people report touch-screen malfunction.
That's pretty radical! Maybe it's time to ditch Nexus7 all together?
Bifurcator said:
Any progress?
I think it's almost impossible for it to be the fault of the screen protector. But there are many kinds of touch screens and if the Nexus7 just happens to be using some hybrid that needs pressure then it's certainly possible.
Think of CTS screens (almost) as proximity sensors. They can actually sense (you) from around a foot away quite easily. As the distance decreases the "signal strength" increases. If we apply an arbitrary numerical value to that signal strength it /might/ look something like:
9 inches - 0.01
8 inches - 0.02
7 inches - 0.02
6 inches - 0.03
5 inches - 0.04
4 inches - 0.05
3 inches - 0.07
2 inches - 0.10
1 inches - 0.20
0.1 inches - 1.00
0.001 inches - 2.00
0" full contact - 10.00
But typically the software algorithms which determine whether a touch event has occurred or not imply a threshold value of (again arbitrary for the sake of example), 9.00. The dielectric properties of "the" plastics of interest for protectors and screens have been thoroughly examined and established AFAIK. They do disperse the electrical force somewhat via factors such as air-space between the protector layer and the screen, whatever insulating impurities may be present in the protector material, the material's own molecular structure, and etc. The amount of electrical field dispersion or distortion that occurs through the material is a function of the materials thickness in the case of the materials commonly being used. Maybe you can imagine looking at a flashlight through murky/milky water where the closer you get the stronger the signal and the more clarity (of the source) can be distinguished. Where this "strength/clarity" begins to become a problem for software "touch" detection is usually around 5mm or 6mm (of commonly used material) between your fingertip and the sensor. If different materials are used this distance changes and can change radically. In keeping with my photovoltaic example, if the material in question could act like a tight bundle of optical fibers (only of course conducting electricity and not light) then the "protective" material could be meters thick without being detrimental to the registration of a touch event.
This is why i think it's almost impossible for it to be the fault of the protector... But everything factor's in. Body weight, blood iron content, protector material impurities, humidity (RH), temperature, skin moisture, variations in the Earth's electrical field from area to area and over time, material thickness, the software algorithm's threshold values, and so on. If they all come together in just the wrong way you could experience the touch registration intermittence you are describing - for sure. And with millions and millions of sensor screens being manufactured it could also be faulty connections there too but /that/ would be my very last guess as they really are ultra-simply constructed. If it's charging at all it should (famous last words) work equally across the entire surface area.
---------- Post added at 01:20 AM ---------- Previous post was at 12:58 AM ----------
Have a look at that poll thread tho:
http://forum.xda-developers.com/poll.php?do=showresults&pollid=9771
416 people report screen separation and almost 130 people report touch-screen malfunction.
That's pretty radical! Maybe it's time to ditch Nexus7 all together?
Click to expand...
Click to collapse
There's been no change in screen sensitivity since I removed the screen protector. I think what you're saying may be correct. I have also noticed intermittent multi touch issues present within certain actions such as pinch to zoom where the touch of the secondary finger is constantly flickering in the sense that the connection between the finger and the touch screen is rapidly switching between being detected and not being detected by the device.
I think at this point, it is almost guaranteed that the screen protector was not the cause of the screen sensitivity issues and that it is a defect within the device itself. I think this is quite unfortunate as I was finally able to get a unit without no sign of screen lift.
Maybe it is time to ditch the nexus 7, however I will not be a part of it as I still think that the nexus 7 is a great device which has many uses along with the added benefit of being a nexus device. Besides, I'm still within my 30 day exchange, so this just gives me a reason to return it and grab the 32GB version.
Sent from my Nexus 7 using Tapatalk 2
Kewl,
Yeah, I'm a total n00b and dunno anything about Nexus7 (nor enough other phones to compare it to anything) so if you think it's worth keeping by all means you should.
BTW, did try popping an iron tab or two?
Bifurcator said:
Yep! The difference between a person with an iron deficiency and someone with a goodly amount can be enormous. In typical variations (say a poor iron intake in the diet compounded by a blood donation or menstruation as opposed to a person eating right and supplementing) can be over two times in terms of touch sensitivity.
If there's zero iron in your blood (besides being in danger of immediate death from organ failure.. ) your touch screen will not be able to detect you at all. The iron in an individual's blood creates strings of capacitors between every epidermal surface of the body. When someone creates a capacitance by touching (or actually even moving into proximity) of the sensor's conductor it creates a capacitance (essentially coupling to ground) by adding a second capacitance (you) in parallel to the sensor's capacitance. When such a ground is introduced the charge-time (frequency) of the sensor slows way down and a "touch" is registered. This is the basic premiss (in brief!) behind Capacitive Touch Sensing (CTS). There's other things going on as well depending on the type of touch screen but almost all of them (found in cell phones) depend on this basic principal.
Fun facts aye? LOL
Click to expand...
Click to collapse
Bifurcator said:
I of course wouldn't know if your sensor was defective or not. But the design is extremely simple and the way they work would imply that if it worked in one area of the screen it will work across the entire screen given that the relative dielectric constant is even throughout the material volume. And if it wasn't you would likely see it as thousands of micro-bubbles, cracks, or other aberrations.
Also keep in mind that temperature and humidity have affect as well.
Click to expand...
Click to collapse
Who is this guy? Stephen Hawking?
I need a bloody iron tab after reading all that !!
Bifurcator said:
Kewl,
Yeah, I'm a total n00b and dunno anything about Nexus7 (nor enough other phones to compare it to anything) so if you think it's worth keeping by all means you should.
BTW, did try popping an iron tab or two?
Click to expand...
Click to collapse
Nope! The problem was isolated only to my Nexus 7 and not my HTC Amaze, so I didn't bother.
Sent from my Nexus 7 using Tapatalk 2
Wilks3y said:
Who is this guy? Stephen Hawking?
I need a bloody iron tab after reading all that !!
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Hehe...
MidnightXZ said:
There's been no change in screen sensitivity since I removed the screen protector. I think what you're saying may be correct. I have also noticed intermittent multi touch issues present within certain actions such as pinch to zoom where the touch of the secondary finger is constantly flickering in the sense that the connection between the finger and the touch screen is rapidly switching between being detected and not being detected by the device.
I think at this point, it is almost guaranteed that the screen protector was not the cause of the screen sensitivity issues and that it is a defect within the device itself. I think this is quite unfortunate as I was finally able to get a unit without no sign of screen lift.
Maybe it is time to ditch the nexus 7, however I will not be a part of it as I still think that the nexus 7 is a great device which has many uses along with the added benefit of being a nexus device. Besides, I'm still within my 30 day exchange, so this just gives me a reason to return it and grab the 32GB version.
Sent from my Nexus 7 using Tapatalk 2
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I have been using Huawei G700 for 9 months now but the problem, similar to what you described befell this phone. Sometimes it lags, inaccurate point selections and cant pull the notification bar to the bottom, unless I "hurl" it down. Could it be the screen (no any visible damage) or some internal functioning. I had to reformat it, no solution yet.
I found out what my issue was with the unresponsiveness on my nexus 7 (2013). What it was, was that I didn't remove the protective film from the anti-glare screen protector. I realized it when i was completely going to eliminate the screen protector and see if by doing so my screen would responded better but realized what I was removing was the protective film and not the anti-glare screen protector. My screen is very responsive now.

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