# How do computer touch screens work? **URL:** \ **Category:** Factual Questions\ **Created:** [February 11, 2007, 6:32pm UTC](https://boards.straightdope.com/t/how-do-computer-touch-screens-work/391746 "2007-02-11T18:32:27Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![furryman](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/furryman/32/99_2.png) [@furryman](https://boards.straightdope.com/u/furryman)\ **Post date:** [February 11, 2007, 6:32pm UTC](https://boards.straightdope.com/t/how-do-computer-touch-screens-work/391746/1 "2007-02-11T18:32:27Z")
Like the one you see at grocery stores? ---
**Author:** ![Ice\_Wolf](https://avatars.discourse-cdn.com/v4/letter/i/dfb087/32.png) [@Ice\_Wolf](https://boards.straightdope.com/u/Ice_Wolf)\ **Post date:** [February 11, 2007, 7:02pm UTC](https://boards.straightdope.com/t/how-do-computer-touch-screens-work/391746/2 "2007-02-11T19:02:55Z")
Dunno, but [here’s a Wiki page on them](http://en.wikipedia.org/wiki/Touchscreen) with some extra info links. ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [February 11, 2007, 7:31pm UTC](https://boards.straightdope.com/t/how-do-computer-touch-screens-work/391746/3 "2007-02-11T19:31:24Z")
The ones I use at Kroger require a pretty stiff poke on the screen. I was thinking they used strain gauges (resistance changes and hence voltage when touched) but given Ice Wolf’s link, they may be Dispersive Energy Technology, measuring the energy in the glass of the screen. ---
**Author:** ![rocksolid](https://avatars.discourse-cdn.com/v4/letter/r/8797f3/32.png) [@rocksolid](https://boards.straightdope.com/u/rocksolid)\ **Post date:** [February 11, 2007, 9:17pm UTC](https://boards.straightdope.com/t/how-do-computer-touch-screens-work/391746/4 "2007-02-11T21:17:09Z")
Cant beat [howstuffworks.com](http://howstuffworks.com) for these kind of questions… > **[How do touch-screen monitors know where you're touching?](https://computer.howstuffworks.com/question716.htm)** > > Touch-screen monitors have become more and more commonplace as their price has steadily dropped. There are three basic systems that are used to recognize a person's touch -- learn how they work. ---
**Author:** ![Will\_Repair](https://avatars.discourse-cdn.com/v4/letter/w/a698b9/32.png) [@Will\_Repair](https://boards.straightdope.com/u/Will_Repair)\ **Post date:** [February 12, 2007, 9:03pm UTC](https://boards.straightdope.com/t/how-do-computer-touch-screens-work/391746/5 "2007-02-12T21:03:36Z")
No cite but capacitance type seems the most popular. ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [February 12, 2007, 9:09pm UTC](https://boards.straightdope.com/t/how-do-computer-touch-screens-work/391746/6 "2007-02-12T21:09:01Z")
[QUOTE=Will Repair] No cite but capacitance type seems the most popular. [/QUOTE] How hard do you have to touch a cap screen? Kroger’s have to be poked pretty well. I wonder if I’d get arrested or anything if I tried to work them in gloves…in the way of fighting ignorance, you understand. ---
**Author:** ![Sunrazor](https://avatars.discourse-cdn.com/v4/letter/s/2acd7d/32.png) [@Sunrazor](https://boards.straightdope.com/u/Sunrazor)\ **Post date:** [February 12, 2007, 9:22pm UTC](https://boards.straightdope.com/t/how-do-computer-touch-screens-work/391746/7 "2007-02-12T21:22:15Z")
You learn the darnedest stuff around here! I remember back in the early 1980s, the administrative assistant to the publisher at the newspaper where I worked had a touch-screen computer. There were tiny holes in the inside of the frame around the screen; I was told the monitor used tiny lights in the holes to tell where the monitor was being touched. The Wikipedia article referenced above describes it – I was absolutely fascinated with it! ---
**Author:** ![Will\_Repair](https://avatars.discourse-cdn.com/v4/letter/w/a698b9/32.png) [@Will\_Repair](https://boards.straightdope.com/u/Will_Repair)\ **Post date:** [February 12, 2007, 9:25pm UTC](https://boards.straightdope.com/t/how-do-computer-touch-screens-work/391746/8 "2007-02-12T21:25:10Z")
Try cleaning it, glass cleaner with no ammonia or a specfic touch screen cleaner from Happ Controls. They get dirty, just like money (and coin acceptors.) They also have a high failure rate.