Patents by Inventor Hsienhui CHENG

Hsienhui CHENG 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: 20220390773
    Abstract: Systems and methods for providing an electrical waveform to a pi-cell polarization switch. The electrical waveform may reduce/limit ion accumulation in and/or light leakage associated with the polarization switch. The electrical waveform may include multiple segments, e.g., a first segment may drive the polarization switch to a first polarization state and may be defined by a first portion having a first voltage level and a first polarity and a second portion having the first voltage level and a second polarity opposite the first polarity and a second segment, occurring after the first segment, that may drive the polarization switch to the second polarization state. The second segment may be defined by a second voltage level having the first polarity. An absolute value of the first voltage level may be greater than an absolute value of the second voltage level.
    Type: Application
    Filed: August 16, 2022
    Publication date: December 8, 2022
    Inventors: Hsienhui Cheng, Jianhong Huang
  • Patent number: 11435602
    Abstract: Systems and methods for providing an electrical waveform to a pi-cell polarization switch. The electrical waveform may reduce/limit ion accumulation in and/or light leakage associated with the polarization switch. The electrical waveform may include multiple segments, e.g., a first segment may drive the polarization switch to a first polarization state and may be defined by a first portion having a first voltage level and a first polarity and a second portion having the first voltage level and a second polarity opposite the first polarity and a second segment, occurring after the first segment, that may drive the polarization switch to the second polarization state. The second segment may be defined by a second voltage level having the first polarity. An absolute value of the first voltage level may be greater than an absolute value of the second voltage level.
    Type: Grant
    Filed: December 12, 2019
    Date of Patent: September 6, 2022
    Assignee: ZSPACE, INC.
    Inventors: Hsienhui Cheng, Jianhong Huang
  • Publication number: 20210181540
    Abstract: Systems and methods for providing an electrical waveform to a pi-cell polarization switch. The electrical waveform may reduce/limit ion accumulation in and/or light leakage associated with the polarization switch. The electrical waveform may include multiple segments, e.g., a first segment may drive the polarization switch to a first polarization state and may be defined by a first portion having a first voltage level and a first polarity and a second portion having the first voltage level and a second polarity opposite the first polarity and a second segment, occurring after the first segment, that may drive the polarization switch to the second polarization state. The second segment may be defined by a second voltage level having the first polarity. An absolute value of the first voltage level may be greater than an absolute value of the second voltage level.
    Type: Application
    Filed: December 12, 2019
    Publication date: June 17, 2021
    Inventors: Hsienhui Cheng, Jianhong Huang
  • Patent number: 10613405
    Abstract: Techniques are disclosed relating to the transmission of data based on a polarization of a light signal. In some embodiments, data may include 3D video data for viewing by a user. Systems for transmitting data may include a display device and a device for switching the polarization of a video source. Systems for receiving data may include eyewear configured to present images with orthogonal polarization to each eye. In some embodiments, the rate of switching of the polarization switcher may introduce a distortion to the optical data. A Pi-cell device may be used in some embodiments to reduce distortion based on switching speed. In some embodiments, polarization switchers may introduce a distortion based on the frequency of transmitted light. In some embodiments, optical elements including in the transmitting or receiving devices may be configured to reduce distortions based on frequency.
    Type: Grant
    Filed: November 28, 2018
    Date of Patent: April 7, 2020
    Assignee: zSpace, Inc.
    Inventors: HsienHui Cheng, Thanh-Son Nguyen
  • Patent number: 10338303
    Abstract: Systems and methods for increasing dynamic contrast in a liquid crystal display (LCD) may include a segmented backlight that may include one or more segments and one or more sets of light emitting diodes (LEDs). Each set of LEDs may be configured to illuminate a corresponding segment and each segment may include a notch(es) configured as a light barrier to reduce light leakage to non-adjacent segments. The notch(es) may be of variable length, depth, and width and may be three-dimensional, having a width the varies along the depth and length of the notch and a depth that varies along the width and length of the notch. In some embodiments, the notch(es) may be reflective, some degree of opaque, and/or blackened.
    Type: Grant
    Filed: October 15, 2018
    Date of Patent: July 2, 2019
    Assignee: zSpace, Inc.
    Inventors: Thanh-Son Nguyen, Hsienhui Cheng
  • Publication number: 20190094586
    Abstract: Techniques are disclosed relating to the transmission of data based on a polarization of a light signal. In some embodiments, data may include 3D video data for viewing by a user. Systems for transmitting data may include a display device and a device for switching the polarization of a video source. Systems for receiving data may include eyewear configured to present images with orthogonal polarization to each eye. In some embodiments, the rate of switching of the polarization switcher may introduce a distortion to the optical data. A Pi-cell device may be used in some embodiments to reduce distortion based on switching speed. In some embodiments, polarization switchers may introduce a distortion based on the frequency of transmitted light. In some embodiments, optical elements including in the transmitting or receiving devices may be configured to reduce distortions based on frequency.
    Type: Application
    Filed: November 28, 2018
    Publication date: March 28, 2019
    Inventors: HsienHui Cheng, Thanh-Son Nguyen
  • Publication number: 20190049653
    Abstract: Systems and methods for increasing dynamic contrast in a liquid crystal display (LCD) may include a segmented backlight that may include one or more segments and one or more sets of light emitting diodes (LEDs). Each set of LEDs may be configured to illuminate a corresponding segment and each segment may include a notch(es) configured as a light barrier to reduce light leakage to non-adjacent segments. The notch(es) may be of variable length, depth, and width and may be three-dimensional, having a width the varies along the depth and length of the notch and a depth that varies along the width and length of the notch. In some embodiments, the notch(es) may be reflective, some degree of opaque, and/or blackened.
    Type: Application
    Filed: October 15, 2018
    Publication date: February 14, 2019
    Inventors: Thanh-Son Nguyen, Hsienhui Cheng
  • Patent number: 10180614
    Abstract: Techniques are disclosed relating to the transmission of data based on a polarization of a light signal. In some embodiments, data may include 3D video data for viewing by a user. Systems for transmitting data may include a display device and a device for switching the polarization of a video source. Systems for receiving data may include eyewear configured to present images with orthogonal polarization to each eye. In some embodiments, the rate of switching of the polarization switcher may introduce a distortion to the optical data. A Pi-cell device may be used in some embodiments to reduce distortion based on switching speed. In some embodiments, polarization switchers may introduce a distortion based on the frequency of transmitted light. In some embodiments, optical elements including in the transmitting or receiving devices may be configured to reduce distortions based on frequency.
    Type: Grant
    Filed: July 14, 2017
    Date of Patent: January 15, 2019
    Assignee: zSpace, Inc.
    Inventors: HsienHui Cheng, Thanh-Son Nguyen
  • Patent number: 10146004
    Abstract: Systems and methods for increasing dynamic contrast in a liquid crystal display (LCD) may include a segmented backlight that may include one or more segments and one or more sets of light emitting diodes (LEDs). Each set of LEDs may be configured to illuminate a corresponding segment and each segment may include a notch(es) configured as a light barrier to reduce light leakage to non-adjacent segments. The notch(es) may be of variable length, depth, and width and may be three-dimensional, having a width the varies along the depth and length of the notch and a depth that varies along the width and length of the notch. In some embodiments, the notch(es) may be reflective, some degree of opaque, and/or blackened.
    Type: Grant
    Filed: January 16, 2018
    Date of Patent: December 4, 2018
    Assignee: zSpace, Inc.
    Inventors: Thanh-Son Nguyen, Hsienhui Cheng
  • Publication number: 20180203179
    Abstract: Systems and methods for increasing dynamic contrast in a liquid crystal display (LCD) may include a segmented backlight that may include one or more segments and one or more sets of light emitting diodes (LEDs). Each set of LEDs may be configured to illuminate a corresponding segment and each segment may include a notch(es) configured as a light barrier to reduce light leakage to non-adjacent segments. The notch(es) may be of variable length, depth, and width and may be three-dimensional, having a width the varies along the depth and length of the notch and a depth that varies along the width and length of the notch. In some embodiments, the notch(es) may be reflective, some degree of opaque, and/or blackened.
    Type: Application
    Filed: January 16, 2018
    Publication date: July 19, 2018
    Inventors: Thanh-Son Nguyen, Hsienhui Cheng
  • Publication number: 20180017820
    Abstract: Techniques are disclosed relating to the transmission of data based on a polarization of a light signal. In some embodiments, data may include 3D video data for viewing by a user. Systems for transmitting data may include a display device and a device for switching the polarization of a video source. Systems for receiving data may include eyewear configured to present images with orthogonal polarization to each eye. In some embodiments, the rate of switching of the polarization switcher may introduce a distortion to the optical data. A Pi-cell device may be used in some embodiments to reduce distortion based on switching speed. In some embodiments, polarization switchers may introduce a distortion based on the frequency of transmitted light. In some embodiments, optical elements including in the transmitting or receiving devices may be configured to reduce distortions based on frequency.
    Type: Application
    Filed: July 14, 2017
    Publication date: January 18, 2018
    Inventors: HsienHui Cheng, Thanh-Son Nguyen
  • Patent number: 9261745
    Abstract: A phase retarder comprises first and second ?-cells or other tunable birefringent devices arranged optically in series. The phase retardation value of the phase retarder is a difference between the phase retardation values of the first and second ?-cells. Driving circuitry drives the phase retarder to generate a target phase retardation value by: (1) prior to a relaxation period, biasing the ?-cells to produce the target phase retardation value; (2) during the relaxation period, biasing the first ?-cell at a constant bias value; and (3) during the relaxation period, lowering the bias value of the second ?-cell continuously or stepwise to maintain the target phase retardation value for the phase retarder throughout the relaxation period. In some embodiments the operation (2) comprises applying zero bias to the first ?-cell throughout the relaxation period. In some embodiments the operation (1) comprises applying a maximum operational bias to the second ?-cell.
    Type: Grant
    Filed: May 13, 2013
    Date of Patent: February 16, 2016
    Assignee: Kent State University
    Inventors: Hsienhui Cheng, Achintya Bhowmik, Philip J. Bos
  • Publication number: 20140333875
    Abstract: A phase retarder comprises first and second ?-cells or other tunable birefringent devices arranged optically in series. The phase retardation value of the phase retarder is a difference between the phase retardation values of the first and second ?-cells. Driving circuitry drives the phase retarder to generate a target phase retardation value by: (1) prior to a relaxation period, biasing the ?-cells to produce the target phase retardation value; (2) during the relaxation period, biasing the first ?-cell at a constant bias value; and (3) during the relaxation period, lowering the bias value of the second ?-cell continuously or stepwise to maintain the target phase retardation value for the phase retarder throughout the relaxation period. In some embodiments the operation (2) comprises applying zero bias to the first ?-cell throughout the relaxation period. In some embodiments the operation (1) comprises applying a maximum operational bias to the second ?-cell.
    Type: Application
    Filed: May 13, 2013
    Publication date: November 13, 2014
    Inventors: Hsienhui CHENG, Achintya Bhowmik, Philip J. Bos