Abstract: An acoustic fingerprint imaging system having a plurality of acoustic elements, each acoustic element including a transducer, and independent drive and sense circuitry is disclosed. Drive circuitry may require higher voltage than low voltage sense circuitry. Many embodiments described herein include a ground shifting controller to apply a voltage bias to the low voltage sense circuitry during a drive operation, in order to prevent electrical damage to the sense circuitry.

Abstract: A finger biometric sensing device may include drive circuitry for generating a drive signal and an array of finger biometric sensing pixel electrodes cooperating with the drive circuitry and generating a detected signal based upon placement of a finger adjacent the array. The detected signal may include a drive signal component and a sense signal component superimposed thereon. A gain stage may be coupled to the array and drive signal nulling circuitry may be coupled to the gain stage for reducing the drive signal component from the detected signal. The drive signal nulling circuitry may include a first digital-to-analog converter (DAC) generating an inverted scaled replica of the drive signal for the gain stage. Error compensation circuitry includes a memory storing error compensation data and a second DAC coupled in series with the first DAC compensating an error in the inverted scaled replica based upon the error compensation data.

Abstract: A fingerprint sensor is incorporated in a display stack in an electronic device. A single fingerprint can be captured at one time at a single pre-defined fixed location on a display. Alternatively, a single fingerprint can be acquired at one time at any location on a display. Alternatively, multiple touches on the display can be acquired substantially simultaneously where only one fingerprint is captured at a time or where all of the fingerprints are acquired at the same time. The fingerprint sensor can be implemented as an integrated circuit connected to a bottom surface of a cover sheet, near the bottom surface of the cover sheet, or connected to a top surface of a display. Alternatively, the fingerprint sensor can be implemented as a full panel fingerprint sensor.

Abstract: A capacitive fingerprint sensor includes an array of capacitive sensing elements, readout circuitry electrically coupled to the array of capacitive sensing elements, a block first digital to analog converter (DAC), at least one second DAC, and at least one summing junction electrically coupled to the readout circuitry, the first DAC, and the at least one second DAC. The readout circuitry is adapted to read out pixel voltages from a group of each block of capacitive sensing elements. The first DAC is adapted to provide a block baseline voltage for each block of capacitive sensing elements. The second DAC is adapted to provide a pixel baseline voltage difference for one capacitive sensing element of each group of each block. The summing junction is adapted to subtract the received block baseline voltage and the received pixel baseline voltage difference from the corresponding pixel voltage of each row of each block.

Abstract: A finger biometric sensing device may include drive circuitry for generating a drive signal and an array of finger biometric sensing pixel electrodes cooperating with the drive circuitry and generating a detected signal based upon placement of a finger adjacent the array. The detected signal may include a drive signal component and a sense signal component superimposed thereon. A gain stage may be coupled to the array and drive signal nulling circuitry may be coupled to the gain stage for reducing the drive signal component from the detected signal. The drive signal nulling circuitry may include a first digital-to-analog converter (DAC) generating an inverted scaled replica of the drive signal for the gain stage. Error compensation circuitry includes a memory storing error compensation data and a second DAC coupled in series with the first DAC compensating an error in the inverted scaled replica based upon the error compensation data.

Abstract: A capacitive fingerprint sensor that may be formed of an array of sensing elements. Each capacitive sensing element of the array may register a voltage that varies with the capacitance of a capacitive coupling. A finger may capacitively couple to the individual capacitive sensing elements of the sensor, such that the sensor may sense a capacitance between each capacitive sensing element and the flesh of the fingerprint. The capacitance signal may be detected by sensing the change in voltage on the capacitive sensing element as the relative voltage between the finger and the sensing chip is changed. Alternately, the capacitance signal may be detected by sensing the change in charge received by the capacitive sensing elements as the relative voltage between the finger and the sensing chip is changed.

Abstract: A finger biometric sensing device may include drive circuitry for generating a drive signal and an array of finger biometric sensing pixel electrodes cooperating with the drive circuitry and generating a detected signal based upon placement of a finger adjacent the array. The detected signal may include a drive signal component and a sense signal component superimposed thereon. A gain stage may be coupled to the array and drive signal nulling circuitry may be coupled to the gain stage for reducing the drive signal component from the detected signal. The drive signal nulling circuitry may include a first digital-to-analog converter (DAC) generating an inverted scaled replica of the drive signal for the gain stage. Error compensation circuitry includes a memory storing error compensation data and a second DAC coupled in series with the first DAC compensating an error in the inverted scaled replica based upon the error compensation data.

Abstract: An acoustic fingerprint imaging system having a plurality of acoustic elements, each acoustic element including a transducer, and independent drive and sense circuitry is disclosed. Drive circuitry may require higher voltage than low voltage sense circuitry. Many embodiments described herein include a ground shifting controller to apply a voltage bias to the low voltage sense circuitry during a drive operation, in order to prevent electrical damage to the sense circuitry.

Abstract: A biometric sensing system includes discrete ultrasonic transducers, a first electrode layer disposed over a first surface of the discrete ultrasonic transducers, and a second electrode layer disposed over a second surface of the discrete ultrasonic transducers. The first electrode layer may be a sheet of conductive material that is a common ground connection for the discrete ultrasonic transducers. Alternatively, the first electrode layer can be formed with discrete electrode elements, with a discrete electrode element disposed over the first surface of a discrete ultrasonic transducer. The second electrode layer may be formed with discrete electrode elements, with a discrete electrode element disposed over the second surface of one ultrasonic transducer. At least one integrated circuit can be attached and connected to one of the electrode layers. The integrated circuit includes drive circuits and sense circuits for the discrete ultrasonic transducers.

Abstract: An acoustic fingerprint imaging system having a plurality of acoustic elements, each acoustic element including a transducer, and independent drive and sense circuitry is disclosed. Drive circuitry may require higher voltage than low voltage sense circuitry. Many embodiments described herein include a ground shifting controller to apply a voltage bias to the low voltage sense circuitry during a drive operation, in order to prevent electrical damage to the sense circuitry.

Abstract: A capacitive fingerprint sensor that may be formed of an array of sensing elements. Each capacitive sensing element of the array may register a voltage that varies with the capacitance of a capacitive coupling. A finger may capacitively couple to the individual capacitive sensing elements of the sensor, such that the sensor may sense a capacitance between each capacitive sensing element and the flesh of the fingerprint. The capacitance signal may be detected by sensing the change in voltage on the capacitive sensing element as the relative voltage between the finger and the sensing chip is changed. Alternately, the capacitance signal may be detected by sensing the change in charge received by the capacitive sensing elements as the relative voltage between the finger and the sensing chip is changed.

Abstract: Input members with capacitive sensors are disclosed. In one embodiment of an electronic button, a first circuit is configured to capture a fingerprint of a user's finger placed on the electronic button, and a second circuit is configured to sense a force applied to the electronic button by the user's finger. The first circuit is further configured to provide temperature information to compensate for temperature sensitivities of the second circuit, and the second circuit is further configured to provide force information to the first circuit.

Abstract: Input members with capacitive sensors are disclosed. In one embodiment of an electronic button, a first circuit is configured to capture a fingerprint of a user's finger placed on the electronic button, and a second circuit is configured to sense a force applied to the electronic button by the user's finger. The first circuit is further configured to provide temperature information to compensate for temperature sensitivities of the second circuit, and the second circuit is further configured to provide force information to the first circuit.

Abstract: A biometric sensing system includes discrete ultrasonic transducers, a first electrode layer disposed over a first surface of the discrete ultrasonic transducers, and a second electrode layer disposed over a second surface of the discrete ultrasonic transducers. The first electrode layer includes discrete electrode members. Each discrete electrode member spans two or more discrete ultrasonic transducers. The second electrode layer includes discrete electrode elements, with a discrete electrode element disposed over the second surface of one ultrasonic transducer. Drive circuitry is operably connected to the first electrode layer, and readout circuitry is operably connected to the second electrode layer.

Abstract: A capacitive fingerprint sensor, including: a dielectric structure having a contact surface and a sensor surface; an array of capacitive sensing elements held on or near the sensor surface of the dielectric structure; and an electrostatic lens formed within the dielectric structure.

Abstract: A finger biometric sensor may include first and second integrated circuit (IC) dies arranged in a stacked relation. The first IC die may include a first semiconductor substrate and an array of finger biometric sensing pixels thereon, and the second IC die may include a second semiconductor substrate and processing circuitry thereon coupled to the array of finger biometric sensing pixels. The first and second IC dies may each have respective first and second non-rectangular shapes, such as circular shapes that are coextensive.

Abstract: Methods and devices for testing flex cable shielding of a consumer electronic device are provided. In one example, a method may include applying a signal across a first portion of the flex cable shielding and a second portion of the flex cable shielding. The method may also include detecting a parameter associated with the signal. The method may include determining a health of the flex cable shielding based at least partially on the detected parameter.

Abstract: An acoustic imaging system can contain a plurality of individual acoustic elements that each contain an acoustic transducer, drive circuitry, and low voltage sense and/or read circuitry. In many embodiments both the drive circuitry and the read circuitry can be independently addressable. For example, if the individual acoustic elements are arranged into rows and columns, each acoustic element can include row/column drive circuit enable switches and row/column read circuit enable switches.

Abstract: An acoustic imaging system can include an array of transducers in acoustic communication with a substrate configured to receive a subject for imaging. The transducers can independently or cooperatively send an acoustic pulse into the substrate toward the subject. In many examples, a number of adjacently-positioned transducers are activated substantially simultaneously so as to generate a plane wave into the substrate. After the plane wave has had an opportunity to propagate through the substrate, reflect from the top surface, and propagate through the substrate again, the electrical signals can be obtained from the transducers and an image of the subject can be assembled. In many embodiments, the plurality of transducers can be driven and read in groups such as non-intersecting (disjoint) sets or subarrays.

Abstract: An acoustic fingerprint imaging system having a plurality of acoustic elements, each acoustic element including a transducer, and independent drive and sense circuitry is disclosed. Drive circuitry may require higher voltage than low voltage sense circuitry. Many embodiments described herein include a ground shifting controller to apply a voltage bias to the low voltage sense circuitry during a drive operation, in order to prevent electrical damage to the sense circuitry.