# How Does Touch Screen Work?

**URL:** <https://boards.straightdope.com/t/how-does-touch-screen-work/449595>\
**Category:** Factual Questions\
**Created:** [May 16, 2008, 7:50pm UTC](https://boards.straightdope.com/t/how-does-touch-screen-work/449595 "2008-05-16T19:50:53Z")\
**Posts on this page:** 6\
**Page:** 1

<div class="post-metadata">

**Author:** ![Jinx](https://avatars.discourse-cdn.com/v4/letter/j/c6cbf5/32.png) [@Jinx](https://boards.straightdope.com/u/Jinx)\
**Post date:** [May 16, 2008, 7:50pm UTC](https://boards.straightdope.com/t/how-does-touch-screen-work/449595/1 "2008-05-16T19:50:53Z")

</div>

This is a multi-part question: How does touch screen work? Why do some touch screen interfaces only recognize a (warm-blooded) human touch; yet, others will recognize a stylus? What programming language(s) is/are used to make touch-screen interfaces? And, what is the typical command to tell a program to wait for a touch-screen input, something like READ$ I wager?

Please tell all.

Thanks,

- Jinx

---

<div class="post-metadata">

**Author:** ![Frylock](https://avatars.discourse-cdn.com/v4/letter/f/ce7236/32.png) [@Frylock](https://boards.straightdope.com/u/Frylock)\
**Post date:** [May 16, 2008, 7:57pm UTC](https://boards.straightdope.com/t/how-does-touch-screen-work/449595/2 "2008-05-16T19:57:07Z")

</div>

[QUOTE=Jinx]  
This is a multi-part question: How does touch screen work? Why do some touch screen interfaces only recognize a (warm-blooded) human touch;  
[/QUOTE]

There’s a [bunch of different kinds.](http://en.wikipedia.org/wiki/Touchscreen)

-FrL-

---

<div class="post-metadata">

**Author:** ![Szlater](https://avatars.discourse-cdn.com/v4/letter/s/90ced4/32.png) [@Szlater](https://boards.straightdope.com/u/Szlater)\
**Post date:** [May 16, 2008, 7:57pm UTC](https://boards.straightdope.com/t/how-does-touch-screen-work/449595/3 "2008-05-16T19:57:57Z")

</div>

[QUOTE=Jinx]  
This is a multi-part question: How does touch screen work?  
[/QUOTE]

[Touchscreen](http://en.wikipedia.org/wiki/Touchscreen)

Touchscreen’s can operate using:  
Changes in Electronic Resistance  
Surface acoustic wave  
Capacitive  
Infrared  
Strain gauge  
Optical imaging  
Dispersive signal technology  
Acoustic pulse recognition  
Frustrated Total Internal Reflection  
Diffused Laser Imaging

---

<div class="post-metadata">

**Author:** ![friedo](https://avatars.discourse-cdn.com/v4/letter/f/8edcca/32.png) [@friedo](https://boards.straightdope.com/u/friedo)\
**Post date:** [May 16, 2008, 8:25pm UTC](https://boards.straightdope.com/t/how-does-touch-screen-work/449595/4 "2008-05-16T20:25:48Z")

</div>

[QUOTE=Jinx]  
What programming language(s) is/are used to make touch-screen interfaces?

[/quote]

Generally, the same programming languages used to write any other GUI program.

> [@](#):
>
> And, what is the typical command to tell a program to wait for a touch-screen input, something like READ$ I wager?

If you’re trying to write an event-driven touch-screen program in Apple ][ BASIC, you should keep directions to the nearest mental ward handy.

(See [event-driven programming](http://en.wikipedia.org/wiki/Event-driven_programming)).

---

<div class="post-metadata">

**Author:** ![CookingWithGas](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cookingwithgas/32/485_2.png) [@CookingWithGas](https://boards.straightdope.com/u/CookingWithGas)\
**Post date:** [May 17, 2008, 12:56am UTC](https://boards.straightdope.com/t/how-does-touch-screen-work/449595/5 "2008-05-17T00:56:45Z")

</div>

I have a WACOM laptop–how does that work? Wikipedia article doesn’t mention it.

---

<div class="post-metadata">

**Author:** ![Szlater](https://avatars.discourse-cdn.com/v4/letter/s/90ced4/32.png) [@Szlater](https://boards.straightdope.com/u/Szlater)\
**Post date:** [May 17, 2008, 1:58am UTC](https://boards.straightdope.com/t/how-does-touch-screen-work/449595/6 "2008-05-17T01:58:29Z")

</div>

[QUOTE=CookingWithGas]  
I have a WACOM laptop–how does that work? Wikipedia article doesn’t mention it.  
[/QUOTE]

If it’s anything like the WACOM tablets (does it require a stylus?) then it’s [electromagnetic resonance](http://en.wikipedia.org/wiki/Wacom#Technology).

I have a Intuos tablet at work and it’s pretty nifty, but I’d love to have one of their LCD tablets.