Patents by Inventor Sumant Ranganathan
Sumant Ranganathan has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 10006828Abstract: Systems and methods for accurately and precisely measuring the resistance of a resistive sensor of a matched resistive sensor pair disposed on opposite surfaces of a substrate. Certain embodiments include coupled each sensor of the matched resistive sensors to a thermally-isolated pair of reference resistors contained within an integrated circuit so as to form a Wheatstone bridge. A controller associated with the integrated circuit can adjust the resistance of the thermally-isolated pair of reference resistors until the ratio of resistances matches to the ratio of resistances between the sensors of the matched pair.Type: GrantFiled: June 24, 2015Date of Patent: June 26, 2018Assignee: Apple Inc.Inventors: Manu Agarwal, John Stephen Smith, Sumant Ranganathan
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Publication number: 20180088735Abstract: Location-based swing compensation for touch sensor panels can improve touch sensing performance. Due to differences in impedance characteristics of touch nodes at different locations in a touch sensor panel (due to differences in routing to touch nodes and due to differences in impedance with respect to ground (loading effects) of touch nodes), touch nodes can have non-uniform bandwidth characteristics which can manifest as non-uniform signal and signal-to-noise ratio (SNR) across the touch sensor panel. Additionally, the non-uniform signal can reduce the effectiveness of bootstrapping. Swing compensated stimulation signals can be applied to various touch nodes based on location and/or impedance characteristics of the various touch nodes. For example, the stimulation voltage can be increased for touch nodes with longer and/or thinner routing traces so that the signal at the touch node can be uniform with other touch nodes whose routing may be shorter and/or thicker.Type: ApplicationFiled: September 7, 2017Publication date: March 29, 2018Inventors: Albert LIN, Shwetabh VERMA, Sumant RANGANATHAN
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Publication number: 20180088733Abstract: An electronic device is disclosed. The electronic device can sense touch on its touch screen while in a sleep state in a manner that allows the electronic device to respond to certain touch inputs, while consuming less power due to touch sensing than while in an awake state. For example, sensing touch during the sleep state can allow the electronic device to wake (e.g., transition from the sleep state to the awake state) in response to detecting a certain touch input (e.g., a tap or other touch input) on its touch screen while in the sleep state. Various ways for the electronic device to sense touch during the sleep state are disclosed.Type: ApplicationFiled: August 30, 2017Publication date: March 29, 2018Inventors: Taif A. SYED, Bingrui YANG, Christopher Tenzin MULLENS, Sumant RANGANATHAN
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Publication number: 20180067584Abstract: Touch sensor configurations for reducing electrostatic discharge events in the border area of a touch sensor panel is disclosed. Touch sensors (e.g., electrodes formed on the cover material and/or the opaque mask) can be susceptible to certain events such as arcing and discharge/joule heating, which may negatively affect touch sensor performance. Examples of the disclosure can include increasing the trace width, spacing, and/or thickness in the border area relative to the trace width, spacing, and/or thickness in the visible/active area along one or more sides of the touch sensor panel. In some examples, touch electrodes can be located exclusively in the visible/active areas along one or more sides of the touch sensor panel, while dummy sections can be included in both the border and visible/active areas. Additionally or alternatively, one or more gaps between adjacent touch electrodes in the border area or serpentine routing can be included.Type: ApplicationFiled: August 30, 2017Publication date: March 8, 2018Inventors: Wencong ZHU, Albert LIN, Alexander A. PENN, Ashray Vinayak GOGTE, Chun-Hao TUNG, Hao ZHANG, Hui ZHOU, John Z. ZHONG, Steven P. HOTELLING, Sudip MONDAL, Sumant RANGANATHAN, Sunggu KANG
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Patent number: 9880664Abstract: Noise in sensor panel measurements can be reduced using a common pixel correction algorithm. Noise can be introduced into touch or force sensor panel measurements, for example, by circuitry of a transmit (Tx) section or a receive (Rx) section coupled to one or more sensing nodes of a sensor panel. For example, a digital-to-analog converter in the transmit section or an analog-to-digital converter in the receive section can introduce low-frequency correlated noise. Additionally, transmit and receive sections can introduce uncorrelated noise into the system. Reference nodes, coupled between Tx and Rx sections, can sense correlated and uncorrelated noise from the Tx and Rx sections. The noise measured at reference nodes can be subtract from signals measured at other sensing nodes coupled to the same Rx channel. The measurement at the reference node can be scaled using a scaling parameter to account for differences between reference nodes and sensing nodes.Type: GrantFiled: September 24, 2015Date of Patent: January 30, 2018Assignee: Apple Inc.Inventors: Manu Agarwal, Jason C. Hu, Dhaval Patel, Shahrooz Shahparnia, Sumant Ranganathan
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Publication number: 20170090668Abstract: Noise in sensor panel measurements can be reduced using a common pixel correction algorithm. Noise can be introduced into touch or force sensor panel measurements, for example, by circuitry of a transmit (Tx) section or a receive (Rx) section coupled to one or more sensing nodes of a sensor panel. For example, a digital-to-analog converter in the transmit section or an analog-to-digital converter in the receive section can introduce low-frequency correlated noise. Additionally, transmit and receive sections can introduce uncorrelated noise into the system. Reference nodes, coupled between Tx and Rx sections, can sense correlated and uncorrelated noise from the Tx and Rx sections. The noise measured at reference nodes can be subtract from signals measured at other sensing nodes coupled to the same Rx channel. The measurement at the reference node can be scaled using a scaling parameter to account for differences between reference nodes and sensing nodes.Type: ApplicationFiled: September 24, 2015Publication date: March 30, 2017Inventors: Manu AGARWAL, Jason C. HU, Dhaval PATEL, Shahrooz SHAHPARNIA, Sumant RANGANATHAN
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Publication number: 20170083152Abstract: Electrode configurations for reducing wobble error for a stylus translating on a surface of a touch sensor panel is disclosed. Electrodes associated with a more linear signal profile can correlate to lower wobble error. In some examples, electrodes can be configured such that the signal profile associated with each electrode is spread to be wider, and thus, more linear. In some configurations, electrodes can include two or more bars extending along the length of the electrode with each bar electrically connected to one another at one or both ends. Bars can be of non-uniform width or spacing. Some configurations can include a “split bar,” which can divide a bar lengthwise in order to improve optical uniformity. In some examples, electrodes can include projections which can interleave with corresponding projections in adjacent electrodes.Type: ApplicationFiled: September 21, 2015Publication date: March 23, 2017Inventors: Alexandre GOUREVITCH, Albert LIN, Isaac CHAN, Martin Paul GRUNTHANER, Prathit BUGNAIT, Seyed Mohammad NAVIDPOUR, Sumant RANGANATHAN
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Publication number: 20170026869Abstract: A system for operating a portable communication device includes a module to operate the portable communication device in a first mode. The system may provide telephony service to a user at a first performance level. The system may determine to operate the portable communication device in a power-save mode that is different from the first mode. The system may operate the portable communication device in the power-save mode and provide telephony service to the user at a second performance level different from the first performance level.Type: ApplicationFiled: September 7, 2012Publication date: January 26, 2017Applicant: Broadcom CorporationInventors: Chun-ying Chen, Pieter Vorenkamp, Neil Y. Kim, Sumant Ranganathan
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Publication number: 20160377501Abstract: Systems and methods for accurately and precisely measuring the resistance of a resistive sensor of a matched resistive sensor pair disposed on opposite surfaces of a substrate. Certain embodiments include coupled each sensor of the matched resistive sensors to a thermally-isolated pair of reference resistors contained within an integrated circuit so as to form a Wheatstone bridge. A controller associated with the integrated circuit can adjust the resistance of the thermally-isolated pair of reference resistors until the ratio of resistances matches to the ratio of resistances between the sensors of the matched pair.Type: ApplicationFiled: June 24, 2015Publication date: December 29, 2016Inventors: Manu Agarwal, John Stephen Smith, Sumant Ranganathan
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Publication number: 20160162011Abstract: 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.Type: ApplicationFiled: September 29, 2015Publication date: June 9, 2016Inventors: Shwetabh VERMA, Shahrooz SHAHPARNIA, Sumant RANGANATHAN, Vivek PANT
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Patent number: 9292127Abstract: 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.Type: GrantFiled: January 28, 2015Date of Patent: March 22, 2016Assignee: BROADCOM CORPORATIONInventors: John Walley, Robert Lukas, David Sobel, Sumant Ranganathan, Tianhao Li
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Publication number: 20150253890Abstract: 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.Type: ApplicationFiled: March 25, 2015Publication date: September 10, 2015Inventors: David A. Sobel, Sumant Ranganathan, Tianhao Li, John S. Walley, Glen Weaver, Kerrynn Jacques de Roche, Pi Sheng Chang
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Publication number: 20150242021Abstract: 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.Type: ApplicationFiled: May 14, 2015Publication date: August 27, 2015Inventors: Glen Weaver, Sumant Ranganathan, Federicao Santiago Cattivelli, Tianhao Li, Bhupesh Kharwa, Satish Vithal Joshi, Kerrynn Jacques de Roche, Pi Sheng Chang
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Publication number: 20150227241Abstract: 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.Type: ApplicationFiled: April 20, 2015Publication date: August 13, 2015Applicant: BROADCOM CORPORATIONInventors: Ian Atkinson, Sumant Ranganathan, Federico Cattivelli, Glen Weaver, John Walley, Tianhao Li, David Sobel
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Patent number: 9066368Abstract: Embodiments provide systems and methods for aligning the supply voltage signal applied to a power amplifier (PA) with the radio frequency (RF) output signal of the PA in a wireless device. The RF output signal is generated by applying a transmit signal to a transmit path of the wireless device. The supply voltage is generated by applying an envelope tracking (ET) signal, based on the transmit signal, to an envelope tracking (ET) path of the wireless device. Embodiments operate by estimating the delays of the ET path and the transmit path, and then controlling a relative delay between the transmit signal and the ET signal accordingly. In an embodiment, estimation of the delays of the ET path and the transmit path is done by correlating respective signals of each path.Type: GrantFiled: June 7, 2012Date of Patent: June 23, 2015Assignee: Broadcom CorporationInventors: Robert Lorenz, Sumant Ranganathan, Xinyu Yu, Sriraman Dakshinamurthy
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Patent number: 9058078Abstract: 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.Type: GrantFiled: March 12, 2012Date of Patent: June 16, 2015Assignee: Broadcom CorporationInventors: Glen Weaver, Sumant Ranganathan, Federico Santiago Cattivelli, Tianhao Li, Bhupesh Kharwa, Satish Vithal Joshi, Kerrynn Jacques de Roche, Pi Sheng Chang
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Patent number: 9054866Abstract: A multimode DSL (digital subscriber line) line driver circuit is disclosed. The line driver circuit includes a switch network that enables the line driver circuit to be switched between multiple DSL communication configurations. Upon receipt of a mode control signal, the line driver circuit switches from a first DSL communication configuration to a second communication configuration. A DSL communication signal configured according to the second DSL communication configuration is received at the line driver circuit. The received DSL communication signal is amplified and/or filtered by the line driver circuit. The received DSL communication signal is transmitted from the line driver circuit. In one example implementation, the line driver circuit may be switched from an asymmetric digital subscriber line (ADSL) configuration to a very high speed digital subscriber line (VDSL) configuration, and may be switched from the VDSL configuration to the ADSL configuration.Type: GrantFiled: April 22, 2008Date of Patent: June 9, 2015Assignee: Broadcom CorporationInventors: Nir Matalon, Sumant Ranganathan
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Publication number: 20150138153Abstract: 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.Type: ApplicationFiled: January 28, 2015Publication date: May 21, 2015Applicant: Broadcom CorporationInventors: John WALLEY, Robert LUKAS, David SOBEL, Sumant RANGANATHAN, Tianhao LI
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Patent number: 9024912Abstract: 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.Type: GrantFiled: December 31, 2012Date of Patent: May 5, 2015Assignee: Broadcom CorporationInventors: Ian Atkinson, Sumant Ranganathan, Federico Cattivelli, Glen Weaver, John Walley, Tianhao Li, David Sobel
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Patent number: 9001072Abstract: 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.Type: GrantFiled: March 9, 2012Date of Patent: April 7, 2015Assignee: Broadcom CorporationInventors: David A. Sobel, Sumant Ranganathan, Tianhao Li, John S. Walley, Glen Weaver, Kerrynn Jacques de Roche, Pi Sheng Chang