Ultrasonic touch detection and decision

Abstract

A method includes receiving energy data associated with an ultrasound input device coupled to a material layer. The energy data comprises a current energy value and past energy values associated with reflected ultrasound signals received at the ultrasound input device in response to the ultrasound input device transmitting emitted signals through the material layer towards an external surface of the material layer. The method can then include comparing the energy data with threshold data to generate a current trigger value for trigger data. The trigger data is indicative of an occurrence of a touch event when the current energy value exceeds a current threshold value of the threshold data. Then the method can include updating the threshold data based on the energy data, the trigger data, and the threshold data. Updating the threshold data comprises generating a subsequent threshold value.

I/We claim: 
     
         1 . A method comprising:
 (A1) providing an ultrasound sensor chip comprising an ultrasound sensor portion, the ultrasound sensor portion comprising at least one transmitting ultrasonic transducer configured for transmitting ultrasound signals in a longitudinal mode and at least one receiving ultrasonic transducer configured for receiving reflected ultrasound signals associated with the transmitted ultrasound signals, the at least one transmitting ultrasonic transducer being separate from the at least one receiving ultrasonic transducer;   (A2) providing at least one material layer, the at least one material layer being mechanically coupled to the ultrasound sensor chip, the at least one material layer comprising a material;   (A3) transmitting, by the at least one transmitting ultrasonic transducer, the transmitted ultrasound signals towards the material layer;   (A4) receiving, by the at least one receiving ultrasonic transducer, the reflected ultrasound signals;   (A5) measuring an energy signal integrated over an energy measurement window, the energy signal being associated with the received reflected ultrasound signals; and   (A6) determining the material of the at least one material layer in accordance with at least the energy signal.   
     
     
         2 . The method of  claim 1 , wherein the ultrasound sensor chip additionally comprises an integrated circuit portion coupled to the ultrasound sensor portion. 
     
     
         3 . The method of  claim 2 , wherein (A5) comprises:
 generating a non-negative analog signal associated with the received reflected ultrasound signals using analog circuitry of the integrated circuit portion; and   measuring the energy signal integrated over the energy measurement window from the non-negative analog signal.   
     
     
         4 . The method of  claim 3 , wherein the measuring of the energy signal integrated over the energy measurement window from the non-negative analog signal is carried out in the integrated circuit portion. 
     
     
         5 . The method of  claim 2 , wherein:
 the method additionally comprises generating a driving signal in the integrated circuit portion; and   the transmitting of the transmitted ultrasound signals comprises generating the transmitted ultrasound signals in response to the driving signal.   
     
     
         6 . The method of  claim 2 , wherein the ultrasound sensor chip comprises the ultrasound sensor portion and the integrated circuit portion wafer-bonded to each other. 
     
     
         7 . The method of  claim 2 , wherein the ultrasound sensor chip comprises the ultrasound sensor portion fabricated directly onto a wafer of the integrated circuit portion. 
     
     
         8 . The method of  claim 1 , wherein:
 the at least one transmitting ultrasonic transducer comprises a plurality of transmitting ultrasonic transducers;   the at least one receiving ultrasonic transducer comprises a plurality of receiving ultrasonic transducers; and   the plurality of transmitting ultrasonic transducers are arranged to surround the plurality of receiving ultrasonic transducers.   
     
     
         9 . The method of  claim 1 , wherein:
 the integrated circuit portion comprises ultrasound transmitting circuitry and ultrasound receiving circuitry;   the ultrasound transmitting circuitry is electrically coupled to the at least one transmitting ultrasonic transducer and not electrically coupled to the at least one receiving ultrasonic transducer; and   the ultrasound receiving circuitry is electrically coupled to the at least one receiving ultrasonic transducer and not electrically coupled to the at least one transmitting ultrasonic transducer.   
     
     
         10 . The method of  claim 1 , wherein the at least one transmitting ultrasonic transducer comprises one or more piezoelectric micromachined ultrasonic transducers, one or more integrated bulk piezoelectric transducers, or one or more non-integrated bulk piezoelectric transducers. 
     
     
         11 . The method of  claim 1 , wherein the at least one receiving ultrasonic transducer comprises one or more piezoelectric micromachined ultrasonic transducers, one or more integrated bulk piezoelectric transducers, or one or more non-integrated bulk piezoelectric transducers. 
     
     
         12 . The method of  claim 1 , wherein (A6) comprises determining the material in accordance with the energy signal and machine vision input. 
     
     
         13 . The method of  claim 1 , wherein (A6) comprises determining an elasticity of the at least one material layer in accordance with at least the energy signal. 
     
     
         14 . The method of  claim 1 , wherein (A6) comprises determining acoustic properties of the at least one material layer in accordance with at least the energy signal. 
     
     
         15 . The method of  claim 1 , wherein:
 the transmitted ultrasound signals comprise respective transmitted ultrasound signals at multiple frequencies;   the reflected ultrasound signals comprise respective reflected ultrasound signals at the multiple frequencies;   the received reflected ultrasound signals comprise respective received reflected ultrasound signals at the multiple frequencies; and   the energy signal comprises a respective energy signal associated with each of the multiple frequencies.   
     
     
         16 . The method of  claim 15 , wherein (A6) comprises:
 determining a highest one of the respective energy signals associated with each of the multiple frequencies (highest energy signal); and   determining the material of the at least one material layer in accordance with the highest energy signal.   
     
     
         17 . The method of  claim 1 , additionally comprising providing the energy signal to a recurrent neural network, the energy signal being used to train the recurrent neural network.