A method for controlling a plurality of ultrasonic transducers in a fingerprint sensing system that comprises a cover plate having a sensing surface configured to be touched by a finger, and a plurality of ultrasonic transducers located at the periphery of the cover plate and configured to transmit an acoustic signal propagating in the cover plate, receive an ultrasonic signal having interacted with an object in contact with the sensing surface, and to determine properties of the object based on the received ultrasonic signal. The method comprises: in response to a first input, controlling the plurality of transducers such that at least a portion of the sensing surface has a first feature detection resolution; and in response to a second input, controlling the plurality of transducers such that at least a portion of the sensing surface has a second feature detection resolution, different from the first feature detection resolution.

Circuit for performing a display driving function and a fingerprint and touch detecting function includes a unity gain buffer amplifier, an operational amplifier integrator, an ADC circuit, and a digital processing circuit coupled to the ADC circuit. An input terminal of the operational amplifier integrator is coupled to a touch sensor. When the circuit is operated under a display driving mode, an input terminal of the unity gain buffer amplifier receives a gray level voltage and an output terminal of the unity gain buffer amplifier is coupled to a display panel. When the circuit is operated under a fingerprint detecting mode, the input terminal and the output terminal of the unity gain buffer amplifier are respectively coupled to a fingerprint sensor and the ADC circuit. When the circuit is operated under a touch detecting mode, an output terminal of the operational amplifier integrator is coupled to the ADC circuit.

A method includes, for a first x-y position of a sensing grid, obtaining first sensed data. The method further includes, for a first sense data layer, determining whether the first sensed data compares favorably to a threshold for the first sense data layer. The method further includes, when the first sensed data compares favorably to the threshold for the first sense data layer; storing a first n-bit value and storing a second n-bit value when it does not. The method further includes, for a second sense data layer, determining whether the first sensed data compares favorably to a threshold for the second sense data layer. The method further includes, when the first sensed data compares favorably to the threshold for the second sense data layer; storing the first n-bit value and storing the second n-bit value when it does not. The method includes similar processing for a second x-y position.

A position detection apparatus includes a sensor, and a controller that detects a position of a first position indicator and a position of a second position indicator through the sensor. The controller continues detecting the position of the first position indicator and halts detecting the position of the second position indicator after a state in which the positions of the first position indicator and the second position indicator are not detected changes to a state in which the position of the first position indicator is detected, and continues both detecting the position of the second position indicator and detecting the position of the first position indicator after the state in which the positions of the first position indicator and the second position indicator are not detected changes to a state in which the position of the second position indicator is detected.

One variation of a method for detecting an input at a touch sensor—including a force-sensitive layer exhibiting variations in local resistance responsive to local variations in applied force on a touch sensor surface and a set of drive and sense electrodes—includes: driving a drive electrode with a drive signal; reading a sense signal from a sense electrode; detecting a alternating-current component and a direct-current component of the sense signal; in response to a magnitude of the direct-current component of the sense signal falling below a threshold magnitude, detecting an input on the touch sensor surface during the scan cycle based on the alternating-current component of the sense signal; and, in response to the magnitude of the direct-current component of the sense signal exceeding the threshold magnitude, detecting the input on the touch sensor surface during the scan cycle based on the direct-current component of the sense signal.

An asynchronous capacitance-to-digital conversion is described that allows for very low-power operation when during inactive periods (when no conductive object is in contact or proximity to the sensing electrodes). Asynchronous operation of a capacitance-to-digital converter (CDC) provides for capacitance-to-digital conversion without the use of system resources and more power intensive circuit elements.

A method for a touch-sensitive display device comprises detecting a position of a stylus touch input relative to a plurality of touch-sensing electrodes, the stylus touch input corresponding to proximity of an active stylus to a display surface. A position of a human hand touch input is detected, corresponding to proximity of a human hand to the display surface. Each of the plurality of touch-sensing electrodes are driven with a first drive signal to communicate data to the active stylus. An electrical grounding condition is detected that interferes with reception of the first drive signal by the active stylus. A hand-proximity-subset of the plurality of touch-sensing electrodes within a threshold distance of the position of the human hand touch input are driven with a second drive signal, different from the first drive signal.

Examples are disclosed relating to computing devices and methods for performing capacitive touch detection in rotatably coupled displays. In one example, a method comprises: in a first display, providing a first signal at a first frequency to a first drive electrode in a first frequency region abutting a first non-coupled side opposite to a first coupled side. Other signals at other frequencies are provided to other drive electrodes in other frequency regions. In a second display, a second signal at the first frequency is provided to a second drive electrode located in a different first frequency region abutting a second coupled side opposite to a second non-coupled side. The other frequency regions of the first display are positioned between the first frequency region and the different first frequency region, thereby spatially separating the first frequency region from the different first frequency region.

A method for touch detection and fingerprint unlocking includes detecting a finger of a user being in contact with a multiresolution touch interface having a low-resolution mode and a high-resolution mode. The method also includes in response to the detecting the finger of the user being in contact with the multiresolution touch interface, determining a touch interaction associated with the detected finger under the low-resolution mode. The method also includes in response to the multiresolution touch interface being locked, switching a finger contact area of the multiresolution touch interface into the high-resolution mode, wherein the finger contact area is determined based at least in part on the determined touch interaction associated with the detected finger. The method also includes detecting a fingerprint in the finger contact area, and unlocking the multiresolution touch interface based at least in part on the detected fingerprint.

A method includes obtaining sensor coordinates corresponding to positions on a sensor pointed to by an electronic pen, and values determined based signals received from the electronic pen; mapping, using a first mapping method, a first set of the sensor coordinates to first display screen coordinates; determining that a first one of the values is greater than or equal to a first threshold value; determining that a second one of the values is less than or equal to a second threshold value, after determining that the first one of the values is greater than or equal to the first threshold value; and in response to determining that the second one of the values is less than or equal to the second threshold value, mapping, using a second mapping method, a second set of the sensor coordinates to a second display screen coordinates.