Emerging Technologies

GaussBrush: Drawing with Magnetic Stylus

People increasingly rely on stylus in some mobile applications, such as taking notes. However, conventional handheld devices overlain a transparent resistive- or capacitive-based touchscreen provide limited supports on stylus detection. For instances, resistive-based panel cannot easily sense its angle of tilt or position where it hovers, capacitive-based panel cannot reliably distinguish between a finger tip event and a stylus tip event, etc. Though using external cameras can capture stylus and identify subtle operations, the sensors are usually lack portability. Some manufacturers have started to integrate an additional stylus sensor with display modules tightly, such as N- trig DuoSense and electromagnetic resonance (EMR) sensors to enhance stylus detection. However, these sensors cannot simply retrofit existed devices, because the sensors need to be integrated with the touchscreen module tightly. Hence, in terms of compatibility, GaussSense, which is an add-on sensing method based on magnetic penetration, is developed to enhance stylus input without losing mobility or the need of modifying the device. In this work, we demonstrate GaussBrush, to show how natural drawing experiences can be provided by GaussSense technology. GaussBrush is a customized magnetic stylus, which can be detected by the a 2mm-thick magnetic sensor grid. Inside the GaussBrush, we embed a 3cm-height-8mm-diameter magnet stack into the stylus to provide strong magnetic field. When the GaussBrush is approaching to the sensor, the stylus position and state can be recognized based on the sensed distribution of magnetic field. Therefore, several features such as discriminating the stylus events from the finger touch events, determining stylus tilt angle and stylus tips pressure, and locating the position above where the stylus hovers can be enabled with ease. The combination of GaussBrush and GaussSense provides a rich extension for Pen+Touch interactions.

Rong-Hao Liang Academia Sinica

Chao-Huai Su
National Taiwan University

Chien-Ting Weng
National Taiwan University

Kai-Yin Cheng
National Taiwan University

Bing-Yu Chen
National Taiwan University

De-Nian Yang
Academia Sinica