In vibrotactile feedback of the touch display, acoustic noise is radiated from the touch surface due to the vibrotactile rendering. The acoustic noise radiated from the touch surface considerably affects tactile perception of vibrotactile feedback. Therefore, in order to deliver the expected tactile effect to the user accurately, sound radiation due to vibrotactile rendering on the surface must be considered. This paper presents a vibrotactile rendering method that radiates a desired sound from the vibrating touch surface. In this method, measured frequency response functions from actuator driving signals to the vibration response of the surface are applied to generate a specific vibration pattern and calculate velocity of the surface. The sound radiation from the surface is estimated through the vibration velocity of the surface. Considering both the vibrotactile rendering and the sound radiation from the surface, the actuator driving signals are optimized. By driving the optimal actuator driving signals, the specific vibration pattern is rendered at the desired position of the surface and the desired sound is radiated from the plate. For experimental validation of the vibrotactile rendering method, the vibration and sound radiation were measured using the experimental touch surface system. Experimental results show that this method accurately rendered the target vibration pattern on the surface and radiated sound from the surface that matches the desired sound well.

Vibrotactile rendering,Sound radiation,Vibro-acoustics,Plate vibration