Ultrasense Systems, Inc.

Invensense, Inc.

Ultrasense System, Inc.

Sina Akhbari

Hao-Yen Tang

Zhongxuan Tu

Mo Maghsoudnia

Man-Chia Chen

Michael Kerby Chen

Daniela Hall

Romain Fayolle

Michael Chen

Deliang Tao

Chunlei Qian

Bruno Flament

Harihar Narasimha-Iyer

Nikhil Apte

Mei-Lin Chan

Shao-Hsiang Lo

Etienne DeForas

Ching-hsun Wei

Lingtao Wang

A force-measuring and touch-sensing integrated circuit device includes a semiconductor substrate, a thin-film piezoelectric stack overlying the semiconductor substrate, piezoelectric micromechanical force-measuring elements (PMFEs), and piezoelectric micromechanical ultrasonic transducers (PMUTs). The thin-film piezoelectric stack includes a piezoelectric layer. The PMFEs and PMUTs are located at respective lateral positions along the thin-film piezoelectric stack, such that each of the PMFEs and PMUTs includes a respective portion of the thin-film piezoelectric stack. Each PMUT has a cavity, the respective portion of the thin-film piezoelectric stack, and first and second PMUT electrodes. Each PMFE has the respective portion of the thin-film piezoelectric stack, and first and second PMFE electrodes. Each PMFE is configured to output voltage signals between the PMFE electrodes in accordance with a time-varying strain at the respective portion of the piezoelectric layer resulting from a low-frequency mechanical deformation.

Force-measuring and touch-sensing integrated circuit device

A force-measuring device includes a first substrate, signal processing circuitry, a thin-film piezoelectric stack overlying the first substrate, and piezoelectric micromechanical force-measuring elements (PMFEs). The thin-film piezoelectric stack includes a piezoelectric layer. The PMFEs are located at respective lateral positions along the thin-film piezoelectric stack. Each PMFE has: (1) a first electrode, (2) a second electrode, and (3) a respective portion of the thin-film piezoelectric stack. The first electrode and the second electrode are positioned on opposite sides of the piezoelectric layer to constitute a piezoelectric capacitor. Each of the PMFEs is configured to output voltage signals (PMFE voltage signals) between the respective first and second electrodes in accordance with a time-varying strain at the respective portion of the piezoelectric layer between the respective first and second electrodes resulting from a low-frequency mechanical deformation. The signal processing circuitry is configured to read at least some of the PMFE voltage signals.

Force-measuring device and related systems

A multi-virtual button finger-touch input system includes a cover layer, force-measuring and touch-sensing integrated circuits (FMTSICs), each coupled to the inner surface of the cover layer corresponding to one of the virtual buttons, an elongate flexible circuit, and a host controller. The FMTSICs are mounted to the elongate flexible circuit. The host controller is in communication with each of the FMTSICs via digital bus wiring. The host controller is configured to: (1) obtain force-localization features and ultrasound-localization features of the FMTSICs and (2) determine whether an event is a finger-touch event or a false-trigger event and if the event is determined to be finger-touch event, identify one of the virtual buttons as a touched virtual button, using at least in part a model that has the force-localization features and the ultrasound-localization features as inputs. The force-localization features and ultrasound-localization features are derived from the PMFE digital data and the PMUT digital data respectively.

Multi-virtual button finger-touch input systems and methods of detecting a finger-touch event at one of a plurality of virtual buttons

A force-measuring device (FMD) assembly for a portable electronic apparatus includes a mid-frame including a base portion, a sidewall portion, and a transition region between the base portion and the sidewall portion, and force-measuring devices coupled to the inner surface of the sidewall portion. The sidewall portion and the transition region are elongate along a longitudinal axis. FMDs are coupled to the inner surface at respective contact regions of the sidewall portion and are separated from each other along the longitudinal axis. Each of the FMDs includes strain-sensing element(s). Each of the FMDs corresponds to a respective sense region of the sidewall portion. The transition region includes a respective elongate slit or trough for each of the sense regions. The respective elongate slit or trough is elongate along the longitudinal axis. Adjacent elongate slits or troughs are separated by a respective rib.

Force-measuring device assembly for a portable electronic apparatus, a portable electronic apparatus, and a method of modifying a span of a sense region in a force-measuring device assembly

A system includes a piezoelectric capacitor assembly and signal processing circuitry coupled to the piezoelectric capacitor assembly. The piezoelectric capacitor assembly includes a piezoelectric member and piezoelectric capacitors located at respective lateral positions along the piezoelectric member. Each piezoelectric capacitor includes: (1) a respective portion of the piezoelectric member, (2) a first electrode, and (3) a second electrode. The first and second electrodes are positioned on opposite side of the piezoelectric member. The piezoelectric capacitors include piezoelectric force-measuring elements (PFEs). The PFEs are configured to output voltage signals between the respective first electrode and the respective second electrode in accordance with a time-varying strain at the respective portion of the piezoelectric member between the respective first electrode and the respective second electrode resulting from a low-frequency mechanical deformation. The signal processing circuitry is configured to read at least some of the PFE voltage signals.

System including piezoelectric capacitor assembly having force-measuring, touch-sensing, and haptic functionalities

A system for mapping data of force transmission from a plurality of force-imparting points to each force-measuring device is disclosed. A linear actuator assembly includes a Z-axis actuator and a slider. A load cell is secured to the slider, such that actuation of the Z-axis actuator is mechanically coupled to a vertical movement of the load cell via the slider. A sample stage includes a sample stage positioner and is configured to retain a sample including at least one force-measuring device. The load cell is configured to impart a time-varying applied force to the sample. The controller is configured to control actuation of the sample positioner to position the load cell at each one of a plurality of force-imparting points on the sample and, for each respective force-imparting point, control the actuation of the Z-axis actuator. A computer is configured to generate a map of data of force transmission from the plurality of force-imparting points to the force-measuring device in accordance with digital transducer data obtained from the force-measuring device upon the imparting of the time-varying applied force at each force-imparting point.

System for mapping force transmission from a plurality of force-imparting points to each force-measuring device and related method

A force-measuring device testing system is disclosed. A linear actuator assembly includes a Z-axis actuator and a slider. A load cell is secured to the slider, such that actuation of the Z-axis actuator is mechanically coupled to a vertical movement of the load cell via the slider. The load cell is configured to impart a time-varying applied force to the sample which includes a force-measuring device. A load cell signal processing circuitry is configured to measure force signals at the load cell and output amplified force signals to the controller. The controller is configured to repeatedly carry out the following until a desired force trajectory has been executed: (1) calculate digital force signals in accordance with the amplified force signals, (2) calculate a next actuation of the Z-axis actuator in accordance with a desired force trajectory and an elastic parameter, and (3) control the actuation of the Z-axis actuator in accordance with its next calculated actuation.

Force-measuring device testing system, force-measuring device calibration system, and a method of calibrating a force-measuring device

A method of distinguishing between a first-type touch event and a second-type touch event is disclosed. A force-measuring and touch-sensing system includes piezoelectric force-measuring elements (PFEs) and piezoelectric ultrasonic transducers (PUTs), wherein each PUT can be configured as a transmitter (PUT transmitter) and/or a receiver (PUT receiver). The force-measuring and touch-sensing system is configured at a sense region. Each PUT transmitter transmits ultrasound signals towards the sense region and voltage signals are generated at the PUT receivers in response to ultrasound signals arriving from the sense region. Voltage signals are generated at PFEs in response to a low-frequency mechanical deformation of the respective piezoelectric capacitors. An event is determined to be a first-type touch event or a second-type touch event depending on a PUT data decrease and a magnitude of PFE data.

Methods of distinguishing among touch events

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.

Ultrasonic touch detection and decision

In a method for determining whether a finger is a real finger at an ultrasonic fingerprint sensor, a sequence of images of a fingerprint of a finger are captured at an ultrasonic fingerprint sensor, wherein the sequence of images includes images captured during a change in contact state between the finger and the ultrasonic fingerprint sensor. A plurality of transient features of the finger is extracted from the sequence of images. A classifier is applied to the plurality of transient features to classify the finger as one of a real finger and a fake finger. It is determined whether the finger is a real finger based on an output of the classifier.

Fake finger detection based on transient features

In a method for determining whether a finger is a real finger at an ultrasonic fingerprint sensor, a first image of a fingerprint pattern is captured at an ultrasonic fingerprint sensor, wherein the first image is based on ultrasonic signals corresponding to a first time of flight range. A second image of the fingerprint pattern is captured at the ultrasonic fingerprint sensor, wherein the second image is based on ultrasonic signals corresponding to a second time of flight range, the second time of flight range being delayed compared to the first time of flight range. A difference in a width of ridges of the fingerprint pattern in the first image compared to the width of ridges of the fingerprint pattern in the second image is quantified. Based on the quantification of the difference, a probability whether the finger is a real finger is determined.

Fake finger detection using ridge features

In a method for modeling a darkfield candidate image at a sensor, a plurality of darkfield images of the sensor is captured, wherein each darkfield image of the plurality of darkfield images is associated with a different operational condition of the sensor. An operational condition of the sensor is determined. A darkfield candidate image comprising a combination of the plurality of darkfield images is modeled based at least in part on the operational condition of the sensor, wherein a contribution of each darkfield image of the plurality of darkfield images is dependent on the operational condition.

Darkfield modeling

A touch sensor chip can comprise an ultrasound sensor layer comprising an array of ultrasonic transducers. The array of ultrasonic transducers can comprise one or more ultrasonic transducers. The touch sensor chip can also comprise an integrated circuit layer coupled to the ultrasound sensor layer. The integrated circuit layer can comprise circuitry configured for driving the array of ultrasonic transducers to generate ultrasound signals and receiving reflected ultrasound signals using the array of ultrasonic transducers. The integrated circuit layer can also comprise circuitry configured for generating an energy signal associated with received reflected ultrasound signals.

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San Jose, CA, United States of America

Sina Akhbari