Broadcom Corporation

Tianhao Li

Sumant Ranganathan

David A Sobel

John S Walley

Glen Weaver

Pi Sheng Chang

Robert M Lukas

Federico Santiago Cattivelli

Satish Vithal Joshi

Kerrynn Jacques De Roche

Bhupesh Kharwa

Ian Atkinson

Provided are systems and methods for providing enhanced touch sensing. One system providing enhanced touch sensing includes a multi-mode touch screen and a processor configured to apply at least one test signal to a sense element of the multi-mode touch screen, detect at least one return signal from the sense element, and then determine a relative position of an object corresponding to the at least one return signal, the multi-mode touch screen being capable of sensing the first object using first and second detection modes. One multi-mode touch screen comprises a multi-mode multi-touch touch screen. One processor is configured to apply an adaptive test signal to a sense element of a touch screen.

Systems and methods for providing enhanced touch sensing

Control circuitry for a touch panel includes a touch panel interface, a memory comprising touch positioning logic, and a controller in communication with the memory and the touch panel interface. The controller is operable, when the touch positioning logic is executed, to perform selected processing of the touch panel, including scanning a touch panel and determining a touch panel blob resulting from a touch, obtaining blob characteristics of the touch panel blob, and determining a position of the blob relative to the touch panel based on the blob characteristics. The blob characteristics can be adjusted to more accurately position the blob in circumstances where the blob is located near the edge of the touch panel, is in close proximity to another blob, or when the touch panel has variation in the received signal noise.

High-accuracy touch positioning for touch panels

Systems and methods are provided that allow a touch sensor, such as a mutual capacitive touch panel, to switch from an operative transmit (TX) frequency at which the mutual capacitive touch panel is driven to an alternative TX frequency. When switching to an alternative TX frequency, an alternative baseline capacitance value corresponding to the alternative TX frequency may be utilized to determine whether a touch event has occurred on the mutual capacitive touch panel. Frame scans can be repeatedly performed at the operative TX frequency and the alternative TX frequency in rapid succession, and an average difference of the frame scans can be calculated and utilized to generate the alternative baseline capacitance value which may be insensitive to sudden ambient changes and moving touch events affecting the mutual touch capacitive panel.

Baseline recalculation after frequency reconfiguration of a mutual capacitive touch controller

Asymmetric scanning logic implements asymmetric panel scanning by scanning some rows on a touch panel more frequently than other rows. Note that although an entire row at a time may be driven, if only particular pixels in the row are of interest (e.g., included in any region of interest for focused asymmetric scanning), then circuitry may power down the receivers for the columns in which the pixels exist to save power. The asymmetric scanning logic facilitates focused attention to specific areas of interest on the touch panel, to compensate, for example, for high noise or low signal strength in those areas of interest.

Asymmetric multi-row touch panel scanning

A method for a touch panel control circuit includes stimulating a touch panel and receiving signals responsive to the stimulating. Based on the received signals, water or another contaminant may be determined to be present on the touch panel. While the contaminant is present on the touch panel, a wet baseline mode of operation in which a different baseline value is used to detect a touch condition for the touch panel. When the contaminant is removed, operation returns to a dry baseline mode.

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Tustin, CA, United States of America

Tianhao Li