Bidirectional ultrasonic sensor system for biometric devices

A method of controlling a biometric sensor system, comprising:

• controlling an ultrasonic transmitter to transmit first ultrasonic waves in a first direction and to simultaneously transmit second ultrasonic waves in a second direction that is opposite the first direction;
• distinguishing first reflected waves from second reflected waves, the first reflected waves corresponding to reflections of the first ultrasonic waves that are received by an ultrasonic receiver array and the second reflected waves corresponding to reflections of the second ultrasonic waves that are received by the ultrasonic receiver array;
• determining first image data corresponding to the first reflected waves;
• and
• determining second image data corresponding to the second reflected waves.

A non-transitory medium having software stored thereon, the software including instructions for:

• controlling an ultrasonic transmitter to transmit first ultrasonic waves in a first direction and to simultaneously transmit second ultrasonic waves in a second direction that is opposite the first direction;
• and
• controlling a control system to:
• distinguish first reflected waves from second reflected waves, the first reflected waves corresponding to reflections of the first ultrasonic waves that are received by an ultrasonic receiver array and the second reflected waves corresponding to reflections of the second ultrasonic waves that are received by the ultrasonic receiver array;
• determine first image data corresponding to the first reflected waves;
• and
• determine second image data corresponding to the second reflected waves.

A smart card, comprising:

• an ultrasonic receiver array;
• an ultrasonic transmitter;
• and
• a control system capable of:
• controlling the ultrasonic transmitter to transmit first ultrasonic waves in a first direction and to simultaneously transmit second ultrasonic waves in a second direction that is opposite the first direction, wherein the first direction is towards a first side of the smart card and the second direction is towards a second side of the smart card;
• distinguishing first reflected waves from second reflected waves, the first reflected waves corresponding to reflections of the first ultrasonic waves that are received by the ultrasonic receiver array and the second reflected waves corresponding to reflections of the second ultrasonic waves that are received by the ultrasonic receiver array;
• determining first image data corresponding to the first reflected waves;
• and
• determining second image data corresponding to the second reflected waves.