# Finding the touching angle on a touch-screen?

I am wondering if it is possible to detect from which direction (or at which angle) a human touches a touchscreen.

Imagine something like this:

Is there any technology out there (e.g. special capacitors) that can determine the angle resulting from touch B (approx. 45 degrees) and that resulting from touch A (approx. 135 degrees)?

I think I am missing the correct keywords to research this.

• I am not sure how you would define a touching angle, my the direction of the finger? what if the finger is bent? What if it is a stylus? Commented Jul 21, 2015 at 9:23
• I think that would extend to the hand and arm.. so imagine a huge screen where multiple people touch the same point from different directions, each arm/finger would approach from a different direction. I would guess the pressure on some places would be higher than other places. But you are right, probably it is challenging because people's fingers look very different and people can point in different ways. Commented Jul 21, 2015 at 9:34
• already hands, and then arms are complex things with lots of ways to bend and hold them, I cant even imagine a rule to properly assign a direction by looking at a situation, let alone envision a mechanism that could do so. I think we have an XY problem here: you think detecting the direction will solve a problem for you, but instead you probably should ask for a solution to that original problem so people can come up with useful alternatives to bent fingers. Btw. I often use my touchscreen with my nose. Commented Jul 21, 2015 at 9:54
• What comes to mind is to detect proximity raster as well as touch. Then do some gradient descent on the bitmap... Commented Jul 21, 2015 at 11:35
• Idea 2) Detect lateral forces acting on the touchsceen. Commented Jul 21, 2015 at 11:36