Reflection Pattern Sensing for Valid Airborne Ultrasound Tactile Display

Airborne ultrasonic tactile displays are widely used for both applied and basic research due to its unique characteristics. However, the sound field output by the display device has not been confirmed directly during operation. In this study, we propose a reflection pattern sensing method based on confocal principle for valid airborne ultrasound tactile presentation. This approach aims imaging of reflective intensity distribution on a target volume area by a transmitter array and a perimeter receiver array. We confirm that the reflection pattern can be quantitatively measured with a spatial resolution of the wavelength. This result shows that the creation of a focus can be confirmed by the position of maximum reflection intensity.