Why don't screen protectors confuse sensitive mobile phone screens?

[JOC2016]

So this is just an "idle curiosity" type question as I try to work out what suddenly made my mobile keep re-booting. So these modern mobiles have REALLY sensitive touch screens. I know that tempered glass screens sometimes cause 'ghost' clicks when they do not fit perfectly, but I wondered why the stick on the screen PVC plastic ones don't confuse the living daylights out of phone touch surfaces where they fit so tightly. Does the phone know it has a screen protector attached and changes the sensitivity of its surface accordingly? My phone didn't start crashing when I installed my screen cover, but I have started to think about how the screens cope with them. Does anyone know?

 

[SpookDroid]

It's because of the material that they're made of and the way screens respond to touch. Think of a stylus. Grab an S-Pen, and try it on a different screen without S-Pen capabilities (or a Wacom digitizer). Does it work? Nope. Now take a capacitive stylus (those rubber tipped ones) and use it on the screen. It works! Because the screen requires some electrical current to be flowing through the touch for it to work. Your finger can conduct that, and the material the capacitive stylus are made of can, too. The protectors need to let this current through, so they're a bit conductive, but since the thin-film ones are too thin, unless they're poorly made, they won't conduct any noticeable current unless touched. Glass ones are trickier, and material stuck between the glass and the screen might trigger 'ghost inputs', not to mention that the added thickness can also reduce the screen's sensitivity.

 

[JOC2016]

SpookDroid - many thanks for the explanation - that is today's thing learned

 

[SpookDroid]

Glad we could help!