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).
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Publication number: 20220390773Abstract: 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: ApplicationFiled: August 16, 2022Publication date: December 8, 2022Inventors: Hsienhui Cheng, Jianhong Huang
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Patent number: 11435602Abstract: 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: GrantFiled: December 12, 2019Date of Patent: September 6, 2022Assignee: ZSPACE, INC.Inventors: Hsienhui Cheng, Jianhong Huang
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Publication number: 20210181540Abstract: 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: ApplicationFiled: December 12, 2019Publication date: June 17, 2021Inventors: Hsienhui Cheng, Jianhong Huang
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Patent number: 10613405Abstract: 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: GrantFiled: November 28, 2018Date of Patent: April 7, 2020Assignee: zSpace, Inc.Inventors: HsienHui Cheng, Thanh-Son Nguyen
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Patent number: 10338303Abstract: 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: GrantFiled: October 15, 2018Date of Patent: July 2, 2019Assignee: zSpace, Inc.Inventors: Thanh-Son Nguyen, Hsienhui Cheng
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Publication number: 20190094586Abstract: 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: ApplicationFiled: November 28, 2018Publication date: March 28, 2019Inventors: HsienHui Cheng, Thanh-Son Nguyen
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Publication number: 20190049653Abstract: 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: ApplicationFiled: October 15, 2018Publication date: February 14, 2019Inventors: Thanh-Son Nguyen, Hsienhui Cheng
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Patent number: 10180614Abstract: 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: GrantFiled: July 14, 2017Date of Patent: January 15, 2019Assignee: zSpace, Inc.Inventors: HsienHui Cheng, Thanh-Son Nguyen
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Patent number: 10146004Abstract: 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: GrantFiled: January 16, 2018Date of Patent: December 4, 2018Assignee: zSpace, Inc.Inventors: Thanh-Son Nguyen, Hsienhui Cheng
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Publication number: 20180203179Abstract: 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: ApplicationFiled: January 16, 2018Publication date: July 19, 2018Inventors: Thanh-Son Nguyen, Hsienhui Cheng
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Publication number: 20180017820Abstract: 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: ApplicationFiled: July 14, 2017Publication date: January 18, 2018Inventors: HsienHui Cheng, Thanh-Son Nguyen
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Patent number: 9261745Abstract: 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: GrantFiled: May 13, 2013Date of Patent: February 16, 2016Assignee: Kent State UniversityInventors: Hsienhui Cheng, Achintya Bhowmik, Philip J. Bos
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Publication number: 20140333875Abstract: 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: ApplicationFiled: May 13, 2013Publication date: November 13, 2014Inventors: Hsienhui CHENG, Achintya Bhowmik, Philip J. Bos