Patents by Inventor Weijun Yao

Weijun Yao 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).

  • Publication number: 20160092015
    Abstract: Systems and method of performing touch and force sensing in an electronic device. The device includes a cover and an array of touch-sensor electrodes disposed below the cover. The first array of electrodes may be configured to sense a touch on the cover using a capacitive sensing scheme. The device also includes a force-sensor drive electrode disposed below the first array of electrodes and a force-sensor sense electrode disposed below the force-sensor drive electrode. The force-sensor drive and sense electrode may be configured to sense a force on the cover. The device also includes a shared drive circuit having an output that is operatively coupled to the array of touch-sensor electrodes and the force-sensor drive electrode.
    Type: Application
    Filed: March 5, 2015
    Publication date: March 31, 2016
    Inventors: Ahmad Al-Dahle, Yingxuan Li, Marduke Yousefpor, Weijun Yao
  • Publication number: 20150331508
    Abstract: An integrated Silicon-OLED display and touch sensor panel is disclosed. The integrated Silicon-OLED display and touch sensor panel can include a Silicon substrate, an array of transistors, one or more metallization layers, one or more vias, an OLED stack, color filters, touch sensors, and additional components and circuitry. Additional components and circuitry can include an electrostatic discharge device, a light shielding, a switching matrix, one or more photodiodes, a near-infrared detector and near-infrared color filters. The integrated Silicon-OLED display and touch sensor panel can be further configured for near-field imaging, optically-assisted touch, and fingerprint detection. In some examples, a plurality of touch sensors and/or display pixels can be grouped into clusters, and the clusters can be coupled to a switching matrix for dynamic change of touch and/or display granularity.
    Type: Application
    Filed: May 16, 2014
    Publication date: November 19, 2015
    Applicant: Apple Inc.
    Inventors: Hyunwoo Henry NHO, Hopil BAE, Weijun YAO, Yingxuan LI, Ahmad AL-DAHLE
  • Publication number: 20150332638
    Abstract: Devices and methods for reducing or eliminating image artifacts are provided. By way of example, a display panel includes a pixels including pixel electrodes configured to receive an image data signal, and common electrodes (VCOMs) configured to receive a common voltage signal. The display panel includes a source driver, which includes a first digital to analog converter (DAC) configured to generate a gamma voltage signal to provide a first adjustment to the image data signal, and a second DAC configured to generate an error correction voltage signal to provide a second adjustment to the image data signal. The second adjustment is configured to adjust the image data signal to compensate for an operational characteristic difference between row pixels and column pixels of the display panel. The source driver includes an output buffer to supply the image data signal to the pixel electrodes.
    Type: Application
    Filed: May 13, 2014
    Publication date: November 19, 2015
    Applicant: APPLE INC.
    Inventors: Yingxuan Li, Weijun Yao, Wei H. Yao, Kingsuk Brahma, Hyunwoo Nho
  • Publication number: 20150331535
    Abstract: A touch controller. The touch controller can include first sense circuitry configured to be coupled to a first electrode on a touch sensor panel, the first sense circuitry configured to sense a first self-capacitance associated with the first electrode, and a first mutual capacitance associated with the first electrode. In some examples, the first sense circuitry can be configured to sense the first self-capacitance and the first mutual capacitance simultaneously. In some examples, the touch controller can further include a first mixer and a second mixer coupled to the first sense circuitry, the first mixer configured to demodulate a first output from the first sense circuitry to extract information about the first self-capacitance from the first output, the second mixer configured to demodulate the first output from the first sense circuitry to extract information about the first mutual capacitance from the first output.
    Type: Application
    Filed: May 16, 2014
    Publication date: November 19, 2015
    Applicant: Apple Inc.
    Inventors: Yingxuan LI, Weijun YAO, Hyunwoo Henry NHO, Wei Hsin YAO
  • Publication number: 20150227232
    Abstract: A self-capacitance touch sensor panel including a plurality of touch electrodes and one or more sense circuits coupled to the touch electrodes. The touch sensor panel also includes at least one offset cancellation circuit coupled to at least one of the touch electrodes and configured to generate an offset cancellation signal to cancel an offset signal at the at least one touch electrode. In some examples, the offset cancellation signal can be an offset cancellation current to cancel an offset current. In some examples, the offset cancellation circuit comprises a variable resistor, and a magnitude of the offset cancellation current is based on a resistance of the variable resistor. In some examples, each touch electrode is coupled to an offset cancellation circuit. In other examples, a single offset cancellation circuit is shared by a plurality of touch electrodes.
    Type: Application
    Filed: February 28, 2014
    Publication date: August 13, 2015
    Applicant: Apple Inc.
    Inventors: Weijun YAO, Taif A. Syed, Yingxuan Li, Ahmad Al-Dahle
  • Publication number: 20150169121
    Abstract: Integrated touch screens are provided including drive lines formed of grouped-together circuit elements of a thin film transistor layer and sense lines formed between a color filter layer and a material layer that modifies or generates light. The common electrodes (Vcom) in the TFT layer can be grouped together during a touch sensing operation to form drive lines. Sense lines can be formed on a separate layer dedicated to only touch hardware.
    Type: Application
    Filed: April 18, 2014
    Publication date: June 18, 2015
    Applicant: Apple Inc.
    Inventors: Weijun Yao, Wei Hsin Yao, Yingxuan Li, Hopil Bae, Ahmad Al-Dahle
  • Publication number: 20150145802
    Abstract: A touch sensor panel configured to switch between a mutual capacitance touch sensing architecture and a self-capacitance touch sensing architecture is provided. The touch sensor panel includes circuitry that can switch the configuration of touch electrodes to act as either drive lines in a mutual capacitance configuration or as sense electrodes in a self-capacitance configuration. The touch sensor panel also includes circuitry that can switch the configuration of touch electrodes to act as either sense lines in a mutual capacitance configuration or as sense electrode in a self-capacitance configuration. By splitting a self-capacitance touch mode into a drive line self-capacitive mode and sense line self-capacitive mode, the touch sensor panel is able to reuse components thus requiring less space, weight and power.
    Type: Application
    Filed: November 25, 2013
    Publication date: May 28, 2015
    Applicant: Apple Inc.
    Inventors: Weijun YAO, Kingsuk BRAHMA, Taif A. SYED
  • Publication number: 20150109213
    Abstract: Systems and processes for encoding and decoding touch signals output by a touch sensor are provided. In one example system, switching circuitry can be used to selectively couple each of the sense lines of a touch sensor to a positive terminal or a negative terminal of a sense amplifier based on the values of the elements of a matrix. The touch signals can be amplified and converted into digital form using a single sense amplifier and an ADC before being decoded using decoding circuitry. The decoding circuitry can decode the digital encoded touch signals by multiplying the digital encoded touch signals by each column of an inverse of the matrix used to encode the touch signals. The result of the decoding can be a set of signals that are representative of the touch signals output by the touch sensor.
    Type: Application
    Filed: October 21, 2013
    Publication date: April 23, 2015
    Applicant: Apple Inc.
    Inventors: Weijun Yao, Yingxuan Li, Ahmad Al-Dahle
  • Publication number: 20150109212
    Abstract: Systems and processes for stimulating a touch sensor panel using orthogonal frequencies are provided. In one example process, the drive lines of the touch sensor panel can be stimulated with stimulation signals having orthogonal frequencies. The orthogonal frequencies can be separated by a frequency that is inversely proportional to an integration time of the touch sensor panel. The touch signals generated in response to the stimulation signals can be amplified, converted into digital form, demodulated using the orthogonal frequencies, and integrated over the integration time. Integrating the demodulated signals over a length of time that is inversely proportional to the frequency spacing between the orthogonal frequencies reduces or eliminates interference in the touch signals caused by the stimulation signals having different frequencies.
    Type: Application
    Filed: October 21, 2013
    Publication date: April 23, 2015
    Applicant: Apple Inc.
    Inventors: Weijun YAO, Ahmad AL-DAHLE, Yingxuan LI, Wei Hsin YAO
  • Patent number: 8021973
    Abstract: A method and system for reducing the inductance on an integrated circuit. The method and system comprises providing a first differential line, including a first input and a first output, the first differential line including at least two bondwire traces which are coupled in parallel. The method and system also comprises providing a second differential line including a second input and a second output, the second differential line including at least two bondwire traces which are coupled in parallel, the first differential line being of opposite polarity to the second differential line. The method and system further comprises cross-coupling of the first input with the second input and the first output with the second output to reduce the inductance caused by bondwire traces. A technique in accordance with the invention uses the coupling factor K to help to further reduce the inductance.
    Type: Grant
    Filed: July 9, 2009
    Date of Patent: September 20, 2011
    Assignee: Ralink Technology (Singapore) Corporation
    Inventor: Weijun Yao
  • Publication number: 20110143690
    Abstract: A radio transceiver is disclosed. The transceiver comprises an integrated circuit. The integrated circuit comprises a transmit path; a first switch coupled in series with the output of the transmit path; a receive path; and a second switch coupled as a shunt with the input of the receive path. The transceiver further comprises a plurality of external matching networks coupled to the transmit and receive paths of the integrated circuit to ensure minimal loading from one path to the other. The transceiver also comprises a shared balun for converting differential signals from the plurality of external matching networks to single ended signals; and an antenna to interface with the single ended signals. A method and system in accordance with an embodiment enables tying together the transmit path and the receive paths of a radio transceiver without the need for an external T/R switch.
    Type: Application
    Filed: December 10, 2009
    Publication date: June 16, 2011
    Applicant: RALINK TECHNOLOGY (SINGAPORE) CORPORATION
    Inventors: Albert Chia-Wen JERNG, Jen-Wei KO, Weijun YAO, Eric Chiyuan LU
  • Publication number: 20110006440
    Abstract: A method and system for reducing the inductance on an integrated circuit. The method and system comprises providing a first differential line, including a first input and a first output, the first differential line including at least two bondwire traces which are coupled in parallel. The method and system also comprises providing a second differential line including a second input and a second output, the second differential line including at least two bondwire traces which are coupled in parallel, the first differential line being of opposite polarity to the second differential line. The method and system further comprises cross-coupling of the first input with the second input and the first output with the second output to reduce the inductance caused by bondwire traces. A technique in accordance with the invention uses the coupling factor K to help to further reduce the inductance.
    Type: Application
    Filed: July 9, 2009
    Publication date: January 13, 2011
    Applicant: RALINK TECHNOLOGY (SINGAPORE) CORPORATION
    Inventor: WEIJUN YAO
  • Patent number: 7619475
    Abstract: A multistage RF amplifier amplifies RF signals used for communication in a WLAN communications system. The multistage RF amplifier comprises a first amplifier circuit coupled to a second amplifier circuit to maximize amplification. A common mode of the first amplifier circuit is coupled to a common mode of the second amplifier circuit to provide a voltage offset. The voltage offset counters voltage changes due to oscillations in the first amplifier circuit, thereby reducing interference from the multistage RF amplifier.
    Type: Grant
    Filed: March 4, 2008
    Date of Patent: November 17, 2009
    Assignee: Ralink Technology (Singapore) Corporation
    Inventor: Weijun Yao
  • Publication number: 20090224831
    Abstract: A multistage RF amplifier amplifies RF signals used for communication in a WLAN communications system. The multistage RF amplifier comprises a first amplifier circuit coupled to a second amplifier circuit to maximize amplification. A common mode of the first amplifier circuit is coupled to a common mode of the second amplifier circuit to provide a voltage offset. The voltage offset counters voltage changes due to oscillations in the first amplifier circuit, thereby reducing interference from the multistage RF amplifier.
    Type: Application
    Filed: March 4, 2008
    Publication date: September 10, 2009
    Applicant: RALINK TECHNOLOGY CORPORATION
    Inventor: Weijun YAO
  • Patent number: 7468638
    Abstract: An integrated transmit/receive (T/R) switch device comprises a substrate, an antenna port to couple with an antenna, a transmitter port to couple with a transmitter, and a receiver port to couple with a receiver. A receive path is provided between the antenna port and the receiver port, and a transmit path is provided between the antenna port and the transmitter port. The transmit path includes a first transistor on the substrate, and the first transistor is coupled in series between the antenna port and the transmitter port. A body node of the first transistor is unconnected, and the substrate is configured to provide a high impedance path from the first transistor to a reference voltage. A second transistor on the substrate is coupled in series between the receiver port and the reference voltage.
    Type: Grant
    Filed: June 19, 2007
    Date of Patent: December 23, 2008
    Assignee: Marvell International Ltd.
    Inventors: King Chun Tsai, Weijun Yao, Dong Hun Shin