My touch screen input is offset when I connect an external HDMI display

July 29, 2016

When you connect your I-Series(+) to an external screen, such as TV, monitor or smart board, the touch input can have an offset. If you press the screen with your finger, the touch input is somewhat offset and you activate an area next to it instead. Usually the offset is minimal in the center of the screen and bigger the further you press to the right or left.

The reason for this behavior is that when you connect your device to a larger external screen, it duplicates your screen to show the same on the external screen. To do this, it scales up the touch area to fit the larger display which gives an amplification of the touch positions from the center towards the outer edges.
There are two ways to solve this:
  1. Set the default multiple-display-mode to Extend (default is Duplicate). The disadvantage is that you have two screen areas instead of both displaying the same, which means you have to move application windows to the screen you want to present them on.
  2. Set the scaling to "Maintain display scaling", which will produce a stretched image on the larger screen but maintain touch functionality
This only affects touch input, eye tracking users can use the default screen settings.