Ridgepad: a High-Precision Touch-Input Device

Christian Holz and Patrick Baudisch
Hasso Plattner Institute, Potsdam, Germany.


Ridgepad: touch precision

Ridgepad derives finger posture and user ID from each touch event and thereby obtains 1.8 times higher touch precision than traditional capacitive sensing. This makes Ridgepad the most accurate touch device that exists. Ridgepad is based on an L SCAN Guardian fingerprint scanner.


Ridgepad is a high-precision touch-input device that is based on the Generalized Perceived Input Point Model. It models touch on per-posture and per-user basis, reduces the fat finger problem, and thereby increases touch input accuracy. Ridgepad extracts posture and user ID from the user's fingerprint during each touch interaction. In a user study, it achieved 1.8 times higher accuracy than a simulated capacitive baseline condition. The increase in accuracy can be used to make touch interfaces more reliable and make touch input truly precise.