Abstract:
Electrode configurations for reducing wobble error for a stylus translating on a surface over and between electrodes of a touch sensor panel is disclosed. In some examples, electrodes associated with a more linear signal profile are correlated with lower wobble error. In some examples, electrodes are coupled to adjacent electrodes via diffusing resistors such that the signal profile for each electrode is spread to be more linear. In some configurations, the value of the diffusing resistors and series resistance associated with an electrode is selected based on a desired signal profile for that electrode. In some examples, the series resistance can include a trace resistance and a compensating resistance. The compensating resistance can compensate for a variance in trace resistance between electrodes, thus making series resistance substantially equal for each of the electrodes.
Abstract:
Power consumption of touch sensing operations for touch sensitive devices can be reduced by implementing a coarse scan (e.g., banked common mode scan) to coarsely detect the presence or absence of an object touching or proximate to a touch sensor panel and the results of the coarse scan can be used to dynamically adjust the operation of the touch sensitive device to perform or not perform a fine scan (e.g., targeted active mode scan). In some examples, the results of the coarse scan can be used to program a touch controller for the next touch sensing frame to idle when no touch event is detected or to perform a fine scan when one or more touch events are detected. In some examples, the results of the coarse scan can be used to abort a scheduled fine scan during the current touch sensing frame when no touch event is detected.
Abstract:
A touch sensor panel is disclosed. In some examples, the touch sensor panel comprises a plurality of touch node electrodes. In some examples, the touch sensor panel comprises a touch controller configured to drive and sense the plurality of touch node electrodes in a fully bootstrapped configuration to obtain a fully bootstrapped touch image, drive and sense the plurality of touch node electrodes in a second configuration, different from the fully bootstrapped configuration, to obtain a second touch image, the second touch image including an effect of water on the touch sensor panel, and determine a final touch image based on the fully bootstrapped touch image and the second touch image, the final touch image not including the effect of the water on the touch sensor panel. In some examples, the second configuration comprises a mutual capacitance configuration. In some examples, the second configuration comprises a partially bootstrapped configuration.
Abstract:
Position-based sensing methods and systems can be used to transmit data from an input device to a touch-sensitive device. For example, the touch sensing system may perform one or more coarse input device sub-scans to determine a coarse location of the input device. The coarse location can be used to select one or more touch sensors (or sensor channels) to sample for decoding data encoded in the stimulation signals from the input device. During one or more fine input device sub-scans, the touch sensing system can determine a fine location of the input device and decode the data from the input device sampled from the selected touch sensors (or sensor channels).
Abstract:
Power consumption of touch sensing operations for touch sensitive devices can be reduced by implementing a coarse scan (e.g., banked common mode scan) to coarsely detect the presence or absence of an object touching or proximate to a touch sensor panel and the results of the coarse scan can be used to dynamically adjust the operation of the touch sensitive device to perform or not perform a fine scan (e.g., targeted active mode scan). In some examples, the results of the coarse scan can be used to program a touch controller for the next touch sensing frame to idle when no touch event is detected or to perform a fine scan when one or more touch events are detected. In some examples, the results of the coarse scan can be used to abort a scheduled fine scan during the current touch sensing frame when no touch event is detected.
Abstract:
A touch sensor panel is disclosed. In some examples, the touch sensor panel comprises a plurality of touch node electrodes. In some examples, the touch sensor panel comprises a touch controller configured to drive and sense the plurality of touch node electrodes in a fully bootstrapped configuration to obtain a fully bootstrapped touch image, drive and sense the plurality of touch node electrodes in a second configuration, different from the fully bootstrapped configuration, to obtain a second touch image, the second touch image including an effect of water on the touch sensor panel, and determine a final touch image based on the fully bootstrapped touch image and the second touch image, the final touch image not including the effect of the water on the touch sensor panel. In some examples, the second configuration comprises a mutual capacitance configuration. In some examples, the second configuration comprises a partially bootstrapped configuration.
Abstract:
Active styli, methods and non-transitory computer readable storage media can be used for mitigating noise coupling from an active stylus to a touch sensing system. An active stylus can include a force sensor that can be used to detect stylus touch-down and lift-off events. Based on a touch-down and lift-off events, the stylus can generate stimulation signals and ramp up or ramp down the amplitude of the stimulation signals. Additionally or alternatively, an active stylus can receive information to synchronize the active stylus with a touch-sensitive device. Based on the information, the stylus can synchronize generation of stimulation signals with the stylus scan performed by the touch-sensitive device. The stimulation signals can be ramped up during a guard band period before a stylus scan and can be ramped down during a guard band period after the stylus scan.
Abstract:
A multi-chip touch architecture for scalability can include one or more touch controller application specific integrated circuits (ASICs), and one or more switching circuits coupled between the one or more touch controller ASICs and the touch sensor panel. The number of touch controller ASICs and switching circuits can be scaled based on the size of the touch sensor panel. The touch controller ASICs can include an interface for data transfer between the touch controller ASICs to allow for parallel processing of an image of touch by more than one touch controller ASIC. The touch controller ASIC can also include a memory directly accessible by more than one processing circuit (e.g., hardware accelerators), and circuitry to dynamically adjust the coupling between portions (e.g., banks) of memory and inputs of the one or more processing circuits to minimize data transfer and improve processing speeds.
Abstract:
Power consumption of touch sensing operations for touch sensitive devices can be reduced by implementing one or more coarse scans to coarsely detect the presence or absence of an object touching or proximate to a touch sensor panel and dynamically adjusting the operation of the touch sensitive device to perform or not perform one or more steps of a fine scan based on the results of the one or more coarse scans. In some examples, the fine scan can be scheduled, and one or more steps of the fine scan can be aborted when no touch is detected at touch sensors scanned during the one or more steps. Sense channels unused due to the aborted fine scan steps can be powered down during aborted fine scan steps.