Digital Content Production via Multi-touch and Digitizer Pen Input on Tablets

Even though we have had tablets for quite some time their true potential has not been unlocked. Software tends to favor one form of input system over another--a combination of digitizer pen and touch tends to be problematic (1, 2, 3).  For this reason, I believe, Apple chose to use finger touch as the sole input method for the Apple iPad.  Windows tablets, and now Android ones, have had both touch and digitizer input.  Yet, even though tablets have palm rejection technology they remain with unintentional touch inputs (UTIs) --and what the video above demonstrates is nothing more than fantasy.  Now, we can prevent UTIs, but only if we think about tracking the angles of the tablet and digitizer.  Let me explain.

Traditional way to prevent UTIs:
  • If the pen is within range, then disable touch and only allow pen input.
  • If the pen is out of range, then disable pen input and only allow touch.
  • (This of course is already implemented in most digitizer-capable tablets.)

Alternative way to prevent UTIs via angles (XY Tilt):
  • Given the tablet's angle, identify a range of allowed angles for the digitizer pen.
  • If the pen's angle is within the specified range and in proximity then disable multi-touch and only allow pen input.
  • If the pen's angle is not within the specified range then disable pen input and allow only touch input.

Both Wacom and N-Trig pens can track the pen as it is interacting with the tablet.  For a Wacom system, when the proximity of the pen is close enough to the tablet's screen the pen is charged (through EMR).  Once the pen is charged the system can analyze the angles of the pen.  The N-Trig pen doesn't need to be charged by proximity, it has a battery in it.  Furthermore the N-Trig 2 pen now can interact with a system's Bluetooth (that's how MS Surface 3 can launch MS OneNote when you press the back-button).  The Wacom digitizer may face a slight delay in acquiring the details of the angle because of the charge time, the N-Trig could be ahead if it has electronics inside that keep track of its angle and it's constantly passing it via BT.  Now, I'm unsure about the specifics of how these pens track their angles, but they do (N-Trig documentation states tilt tracking from vertical to 60deg, but apparently N-Trig's current pen does NOT have XY tilt [details below]).  Other pen technologies may also implement similar features.

The other major component is the tablet.  Most of the ancient Windows tablets did not have a way to track their angles, but most modern systems now have it.  Now, why is this better than just palm rejection? Because palm rejection by itself has problems.  If you use a normal pen or pencil you will notice that the angle of the pen relative to the paper means that it is possible that the pen/pencil will make a mark, or if it has the wrong angle then the pen will not make any mark at all--which works in the analog world--but this same concept also works in the digital realm. So my conclusion is that by implementing tracking of angles in both the tablet and digitizer we prevent UTIs and thus we can turn tablets into great content production systems--as the "Adobe Illustrator CC on MS Surface" video demonstrates.

More info:

N-Trig DuoSense 2 - Tilt XY Not Tracked

After initial publishing of this post I contacted Fusion PR, which helps N-Trig in their PR, so that we could know whether N-Trig's pen has tilt XY as Wacom's EMR pens have.  The response was "No, we do not provide tilt information.  The need for this is not as demanding as it would be for EMR technologies therefore we do not currently provide it with this generation [N-Trig DuoSense 2] of pen.  If there is a compelling use case and market need, we would consider adding this function..."  So at the moment N-Trig is out of the Tilt XY game, thus it cannot prevent unintentional palm presses via tracking angles of the pen.

Wacom ProPen/GripPen - Tilt XY Allowed

ProPen systems have XY Tilt.

Wacom Penabled Tablet PC (X230T) - Tilt XY Not Allowed

In Pen Tablet Properties do Ctrl+Left Click on the About button to launch the Diagnostics window.

Published: Oct 6, 2014


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Hi. My name is Jesse, and I'm a technology enthusiast. I play with technology and share what I find on this blog. If you have any questions then please use the contact form below. I'll get back to you as soon as I can.



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