A tactile and proximity sensing method for 3D touch screen based on capacitance measurements

We propose a tactile and proximity sensor for a 3D touch screen based on capacitance measurements. In the proposed sensor, a parallel plate-type capacitance sensor and plane-type capacitance sensor are layered. The plane-type capacitance sensor detects the object and non-contact position (proximity range), and identifies the material on contact. The parallel plate-type capacitance sensor detects the indentation and precise position of the object on contact. In the experiment, the object and position were detected without contact. In addition, the discrimination of the materials, and the detection of the indentation and precise positions were demonstrated on contact. The proposed sensor may be useful as a 3D touch screen.