Abstract: A speaker unit that has a housing, a lower substrate that is fixed to the housing, a plurality of first ultrasonic vibrators that are arranged on the lower substrate, an upper substrate that is fixed to the housing and has a plurality of openings (OP) formed therein at locations that correspond to the first ultrasonic vibrators, and a plurality of second ultrasonic vibrators that are arranged on the upper substrate.

Abstract: A speaker unit that has a housing, a lower substrate that is fixed to the housing, a plurality of first ultrasonic vibrators that are arranged on the lower substrate, an upper substrate that is fixed to the housing and has a plurality of openings (OP) formed therein at locations that correspond to the first ultrasonic vibrators, and a plurality of second ultrasonic vibrators that are arranged on the upper substrate.

Abstract: A system can include an input for receiving objects having a flat shape; a capacitance sensing network comprising a plurality of capacitance sensors positioned to be proximate to the received objects; an operations section coupled to the capacitance sensing network and configured to perform predetermined operations on the objects; and a processor section coupled to receive capacitance sense values from the capacitance sensors and configured to determine the presence and features of received objects, prior to the objects being forwarded to the operations section.