Resistive vs. Capacitive Touchscreens

[Pooky]

Pros and Cons?

 

[werner]

picture clarity.

no point getting resistive nowdays, and probably everything you find to buy will be capacitive

 

[Sackboy]

Which devices have which type so we can test?

 

[Sensorei]

Resistive is good if you want handwriting recognition. The Nokia 5800 will be resistive. The iPhone is capacitive and has the best touchscreen out there. I don't know about picture quality difference though. What other phones have a resistive touchscreen?

 

[Pooky]

Resistive = All HTC Touch Phones, Samsung Omnia.
Capacitive = iPhone

 

[Sherbang]

Resistive Pro's:
- Can use a stylus, pen as well as your finger
(though fingers aren't very accurate on resistive screens)
- Can be used while wearing gloves
(eg a doctor wearing surgical gloves cant tap a capacitive screen)
- Handwriting recognition
- Cheaper to produce

I don't think there is any implication for picture clarity.

biggest pro for capacitive touch screens is the response speed and the accuracy that can be achieved using your fingers...

 

[Sensorei]

What other mobiles use capacitive touch screens?

 

[Sensorei]

Ok, I just read that the Blackberry Storm and the G1 both have capacitive touchscreens. Nothing beats the iPhone's touchscreen that I have seen so hopefully the G1 will also rock in that dept. Pity about the Storm's retarded onscreen keyboard typing issues that lets it only recognise that you have pushed a letter if you arent already touching another letter.

 

[chris2.0]

And the Palm Pre's capacitive as well...

Yeah, the BB Storm's keyboard is kinda sucky - you actually have to look on the screen above the kb to see what you've typed, as the blue halo surrounding the key being presses is obscured by your thumbs...

 

[docb]

picture clarity.

no point getting resistive nowdays, and probably everything you find to buy will be capacitive

Judging from the above quote and a few others after it, it seems we have our wires crossed.

Let me explain a little;
Resistive touch screen - works by having two pieces of conductive material {plastic} (the screen) separated by a tiny gap. When the two pieces of plastic are made to touch at any point, this is registered as a keypress. This explains why resistive touchscreens can interpret pressure (hard and soft presses) and why they have to be made of plastic or bendable material and why keypresses are most responsive in the middle of the screen (most deformation) than at the edges. Also explains why the slightest touch doesnt always work - although with advances in technology, the size of the gap and the amount of contact required is so minimal that very slight finger pressure does work quite well.
The thing to note here is that both pieces of material have no resting charge, ONLY when contact of the two pieces is made, is there current passing through the screen.

Capacitive screen - These screens have a constant resting charge. When the charge is broken by another electrical field (like the field around you fingertips that your body naturally generates) the difference in charge is recorded and registered as a keypress. This explains why the screen can be made of glass (doesn't need to flex) and why even slight finger touches are registered. Since a charge is required to break/add to the existing field, normal objects like pens and stylii dont work. However, a very thin glove will work (I've tried) as it still allows charge to pass through.

Regarding the responsiveness of the screen, that comes down to quality of the omponets for detecting and analysing the keypresses, and the software that interprets them, something that apple has spent alot of time on.

Another important point: Multi touch is not an inherent feature of all capacitive touch screens, it is a technology that Apple licensed for the iPhone, and which Palm has licensed for the pre, so even though the new Google G1 has a capacitive screen, it doesnt have multitouch support..

Hope this helps

 

[Brawler]

thanks... Didn't know that.

 

[diabolus]

Yea, the easiest way to figure out which one you have, try to use a pen/stylus on it. If it doesn't work = capacitive . If it does = resistive.

Now it's still debatable whether not being able to use a stylus is good...i personally like using a stylus to type/browse as it's more accurate. However it's also down to the OS-software on the phone. Apple mastered the finger friendly design, where Windows Mobile for example still pretty much "wants" a stylus ...that's why even non-keyboard phones [Touch Diamond/Omnia] just don't make one jump with joy ...it's still Win Mobile on there.

As for multi-touch, i believe Windows 7 is coming out with these features....that little annoying touchpad on your laptop? Multi-touch here we come.

 

[mic_y]

well... I don't mind the stylus, but a capacitive screen would be nice.

Is it also not possible to make a special stylus/glove with an insert that would alter the electric field enough for the phone to detect a keypress?