Interactive displays have been intensively used in consumer electronics, e.g., smartphones, for providing highly efficient human-machine Handkerchiefs interactions, assisting users to process a vast amount of data.However, current mainstream interactive displays only support 2-dimensional detection, strongly limiting user experience.In this paper, we present a piezoelectric and capacitive based technique for obtaining 4-dimensional detection, including (x-y axis) location, force, and hovers sensing in interactive displays.
Here, electrodes are located on and underneath the piezoelectric layer, constructing a sandwich structured device.A self-capacitance-based technique is employed for location and hover sensing.Force-induced charges are collected and interpreted as force amplitude.As capacitive and piezoelectric sensing techniques occupy different frequency bands, these two signals can be smoothly separated, and 4-dimensional touch sensing is achieved concurrently, with the recognition of static force and Forearm Crutches hovers touch events.