Synaptics Corporation

Apple Inc.

Adam L Schwartz

Joseph Kurth Reynolds

Petr Shepelev

Joel C Jordan

Tracy Scott Dattalo

Shubha Ramakrishnan

David Hoch

Guozhong Shen

Stephen Christopher Terry

Zaki Moussaoui

Shahrooz Shahparnia

Bob Lee Mackey

Kirk Hargreaves

Ozan Ersan Erdogan

Richard Robert Schediwy

Zhiyuan Hu

Farzaneh Shahrokhi

Ying Wang

Tom R Vandermeijden

Alireza Safaee

John Weinerth

Ye Li

Jeremy Roberson

Hossein Sepahvand

Niloofar Rashidi Mehrabadi

Sumant Ranganathan

David A Sobel

Mihai M Bulea

Gianpaolo Lisi

Erik Jonathon Thompson

Robert J Bolender

Liang Chen

Scott Shaw

Antoin J Russell

Jim Dunphy

Kuntal Sengupta

Ty Bao Lien

Ruiyang Lin

Mandar Kulkarni

Curtis Elia

Nan Wang

Robin Hodgson

Ron Rafer C Floresca

Weihong Qiu

Patrick Smith

Igor Polishchuk

Jeffrey Alan Small

Paul Wickboldt

Shawn P Day

Eric Scott Bohannon

Vivek Pant

Derek Solven

Vladan Petrovic

Rohan Dayal

Kinh Tieu

Matthew A Stevenson

Sanjay Mani

Clyde Washburn

Mohamed Ashraf Sheik-Nainar

Matthew J Chabalko

Krishna Mohan Chinni

Omar Oreifej

Alvin Jee

Justin Mockler

Bjoren Kurt Davis

Yi-Hsun E Cheng

Vijay Venkatesh Mahalingam

Boyan Bonev

Jizhen Fu

Fritz Norby

Kathy Goudarzi

Stepan Starchenko

Marc Ostrowski

Chieh-Feng Tu

Hsiao-Lan Hsu

Michael Cornstock

A wireless charging system having a power transmitter may wirelessly transfer power to a power receiver. Shield saturation, such as saturation of a ferrite structure, in the wireless power receiver may occur under some operating conditions. Saturation can lead to disruptive oscillations in power transfer. The power transmitting may include control circuitry for detecting and mitigating saturation.

Methods and circuitry for mitigating saturation in wireless power systems

A wireless power transfer transmitter can include a transmitter coil configured to deliver power to an inductively coupled receiver coil in a wireless power transfer receiver, a power converter configured to drive the transmitter coil, and means for driving the transmitter coil with a common-mode coupled communication signal to the wireless power transfer receiver. The means for driving the transmitter coil with the common-mode coupled communication signal to the wireless power transfer receiver can include a common mode signal driver configured to receive a data input signal and generate therefrom a signal to be injected into the transmitter coil. Alternatively, the means for driving the transmitter coil with the common-mode coupled communication signal to the wireless power transfer receiver can include a controller configured to drive the inverter with alternating complementary duty cycles.

Inductive power transfer system with common mode channel communication

A wireless power system has a wireless power transmitting device with a wireless power transmitting coil and an inverter. The inverter and wireless power transmitting coil are used to transmit wireless power signals. The wireless power system also has a wireless power receiving device configured to receive the wireless power signals using a wireless power receiving coil. A rectifier in the wireless power receiving device rectifies alternating-current signals from the wireless power receiving coil and produces corresponding direct-current power. Power loss calculations may be used to help determine whether a foreign object might be present in the vicinity of a coupled wireless power transmitter and receiver. In an ecosystem with multiple models of transmitter and multiple models of receiver, model-dependent scaling factors may be maintained and exchanged between a given coupled transmitter and receiver pair to allow accurate power loss estimates to be made.

Wireless power systems with shared inductive-loss scaling factors

A wireless power system has a wireless power transmitting device and a wireless power receiving device. The wireless power transmitting device uses a wireless power transmitting coil to transmit wireless power signals to the wireless power receiving device. The wireless power transmitting device determines whether an external object is present. The external object may be a foreign object such as a coin or paperclip or may be a wireless power receiving device. External objects are detected using quality-factor measurements. Wireless communications are used to discriminate between foreign objects and wireless power receiving devices. Quality factor measurements may be compensated for aging and temperature effects using temperature measurements and compensation factors based on frequency and measured resistance.

Wireless power systems with foreign object detection

An accessory for improving wireless power transfer efficiency in a wireless power transfer system can include a magnetic (e.g., ferrite) core dimensioned and positioned so as to reduce flux coupling from the PTx winding into friendly metal of the PRx and/or to enhance flux coupling from the PTx winding to the PRx winding. The core may define an aperture corresponding to an outer dimension (e.g., outer diameter) of the PRx winding. The core may further have an outer dimension selected to intercept sufficient flux to reduce flux coupling into the friendly metal of the PRx, such as an outer dimension corresponding to an outer dimension (e.g., outer diameter) of the PTx winding. The accessory may be a case for the PRx device or may be configured to be affixed to the face of the PTx device and may also include one or more alignment fixtures.

Accessory devices to improve wireless power transfer efficiency

A wireless power transfer device can include a coil that couples to a corresponding coil of a counterpart device to facilitate wireless power transfer, a power converter coupled to the coil, and controller and communication circuitry that monitors one or more observable parameters associated with the wireless power transfer to detect a presence of a foreign object that is not the counterpart device and controls the power converter responsive to detection of the foreign object. The controller and communication circuitry can perform foreign object detection based on power accounting that includes estimating friendly metal losses associated with the counterpart device. The controller and communication circuitry can interrogate a machine readable tag associated with a case of the counterpart device and can receive from the machine readable tag information about the presence or properties of the case. The machine readable tag can be an NFC tag.

Case detection for wireless power transfer loss estimation

A wireless power transmitter can include a coil, an inverter coupled to the coil, and control circuitry coupled to the inverter that, responsive to receiving a burst request pulse from a wireless power receiver, initiates inverter operation, driving the coil and powering the receiver. The control circuitry can operate inverter switches so bandwidth of the wireless power transfer signal falls within a specified range by: (a) extending a minimum on time of the switches, (b) modifying pulse width modulation (PWM) drive signals supplied to the switches to shape a coil current burst envelope, and/or (c) modifying PWM signal amplitude supplied to the switches. Modifying the PWM drive signals can include using a symmetrical PWM scheme in which the positive and negative pulses are symmetrical in width on a cycle-by-cycle basis or using a complementary PWM scheme in which the positive and negative pulse widths are complementary on a cycle-by-cycle basis.

Frequency management for wireless power transfer

A wireless power transfer device can include a coil that couples to a corresponding coil of a counterpart device to facilitate wireless power transfer, a power converter coupled to the coil, and controller and communication circuitry that monitors one or more observable parameters associated with the wireless power transfer to detect a presence of a foreign object that is not the counterpart device and control the power converter responsive to detection of a foreign object. The controller and communication circuitry can perform foreign object detection based on power accounting that includes estimating friendly metal losses associated with the counterpart device. The controller and communication circuitry can receive from the counterpart device friendly metal loss modeling parameters associated with the counterpart device, the modeling parameters including one or more coefficients relating to a wireless power transfer current and one or more coefficients relating to a wireless power transfer voltage.

Friendly metal loss estimation

A capacitive sensing array includes a first transmitter electrode, a plurality of first receiver electrodes, a second transmitter electrode, and a plurality of second receiver electrodes disposed in a first row of the array. The first transmitter electrode is disposed in a first column of the array and is coupled to a first transmitter channel. The first receiver electrodes are disposed in a second column of the array, adjacent the first transmitter electrode, and are coupled to a respective one of a plurality of first receiver channels. The second transmitter electrode is disposed in a third column of the array and is coupled to a second transmitter channel. The second receiver electrodes are disposed in a fourth column of the array, adjacent the second transmitter electrode, and are coupled to a respective one of the first receiver channels.

Single-layer capacitive image sensor

Growing community of inventors

Redwood City, CA, United States of America

Adam L Schwartz