Patents by Inventor Liang-Chy Chien
Liang-Chy Chien 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: 11434426Abstract: A fast flexoelectro-optic switching device containing bimesogen-doped and polymer-stabilized vertical standing helix (PSVSH) in a cholesteric liquid crystal. The PSVSH device exhibits a response time of less than 0.7 millisecond, high contrast and negligible hysteresis which is suitable for applications including blur-free displays, field-sequential color displays and active optical elements.Type: GrantFiled: March 9, 2018Date of Patent: September 6, 2022Assignee: Kent State UniversityInventors: Liang-Chy Chien, Vinay Joshi, Kai-Han Chang
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Patent number: 11243408Abstract: A speckle reduction system is provided and includes a speckle reduction component and a control module. The speckle reduction component includes electrode layers and a liquid crystal layer. The liquid crystal layer is disposed between the electrode layers and configured to receive light from a coherent light source. The control module is configured to (i) supply a first voltage signal having a first voltage to the electrode layers to provide a first speckle pattern output, and (ii) supply a second voltage signal having a second voltage to the electrode layers to provide a second speckle pattern output, wherein the first voltage and the second voltage are greater than zero. The control module is configured to transition between providing the first voltage signal and the second voltage signal in less than at least one of half an integration time of a human eye or 8 milliseconds.Type: GrantFiled: February 5, 2020Date of Patent: February 8, 2022Assignees: GM GLOBAL TECHNOLOGY OPERATIONS LLC, KENT STATE UNIVERSITYInventors: John Ernest Harden, Jr., Liang-Chy Chien, Kai-Han Chang, Thomas A. Seder
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Patent number: 11221538Abstract: Liquid crystal lenses of different apertures with suppressed chromatic aberration utilizing twisted vertical alignment configuration are demonstrated. A plurality of substrates are provided with electrodes, including a patterned electrode to generate a lens effect. The liquid crystal material is homeotropically aligned, such as via alignment layers. Setting the ratio between cell thickness and chiral pitch of the cholesteric liquid crystals provides correction of axial chromatic aberrations of electrically-tunable focal lengths in the device.Type: GrantFiled: May 18, 2018Date of Patent: January 11, 2022Assignee: KENT STATE UNIVERSITYInventors: Liang-Chy Chien, Kai-Han Chang, Andrii Varanytsia
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Publication number: 20210239996Abstract: A speckle reduction system is provided and includes a speckle reduction component and a control module. The speckle reduction component includes electrode layers and a liquid crystal layer. The liquid crystal layer is disposed between the electrode layers and configured to receive light from a coherent light source. The control module is configured to (i) supply a first voltage signal having a first voltage to the electrode layers to provide a first speckle pattern output, and (ii) supply a second voltage signal having a second voltage to the electrode layers to provide a second speckle pattern output, wherein the first voltage and the second voltage are greater than zero. The control module is configured to transition between providing the first voltage signal and the second voltage signal in less than at least one of half an integration time of a human eye or 8 milliseconds.Type: ApplicationFiled: February 5, 2020Publication date: August 5, 2021Inventors: John Ernest HARDEN, JR., Liang-Chy CHIEN, Kai-Han CHANG, Thomas A. SEDER
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Publication number: 20210181522Abstract: An optical display device includes a coherent light source generating a coherent light beam in visible, ultraviolet, or infrared ranges. The coherent light beam is directed at a liquid crystal component. A plurality of liquid crystals and a plurality of nanoparticles having an average diameter of ?about 450 nm are disposed in an interior compartment. An electrical source is in electrical communication with the first and the second electrodes. When no voltage or current is applied, a filtered light beam transmitted or reflected from the liquid crystal component exhibits a first speckle contrast ?about 0.28. When voltage or current is applied, the microparticles are induced to move and the filtered light beam has a second speckle contrast that is ?about 0.2 and in certain aspects may be ?about 0.03. A method of reducing speckle in an optical device having a coherent light source is also provided.Type: ApplicationFiled: December 11, 2019Publication date: June 17, 2021Inventors: Kai-Han CHANG, John HARDEN, Liang-Chy CHIEN
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Patent number: 11016308Abstract: An optical display device includes a coherent light source generating a coherent light beam in visible, ultraviolet, or infrared ranges. The coherent light beam is directed at a liquid crystal component. A plurality of liquid crystals and a plurality of nanoparticles having an average diameter of ?about 450 nm are disposed in an interior compartment. An electrical source is in electrical communication with the first and the second electrodes. When no voltage or current is applied, a filtered light beam transmitted or reflected from the liquid crystal component exhibits a first speckle contrast ?about 0.28. When voltage or current is applied, the microparticles are induced to move and the filtered light beam has a second speckle contrast that is ?about 0.2 and in certain aspects may be ?about 0.03. A method of reducing speckle in an optical device having a coherent light source is also provided.Type: GrantFiled: December 11, 2019Date of Patent: May 25, 2021Assignees: GM GLOBAL TECHNOLOGY OPERATIONS LLC, KENT STATE UNIVERSITYInventors: Kai-Han Chang, John Harden, Liang-Chy Chien
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Publication number: 20210132404Abstract: An optical device (e.g., display device) includes a coherent light source generating a coherent light beam in a visible, ultraviolet, or infrared range. The coherent light beam is directed at a liquid crystal component. A plurality of liquid crystals and a plurality of microparticles having an average diameter of ?about 450 nm to ?about 20 micrometers (?m) are disposed in an interior compartment. An electrical source is in electrical communication with the first and the second electrodes. When no voltage or current is applied, a filtered light beam transmitted or reflected from the liquid crystal component exhibits a first speckle contrast ?about 0.6. When voltage or current is applied, the microparticles are induced to move and the filtered light beam has a second speckle contrast that is ?about 0.6. A method of reducing speckle in an optical device having a coherent light source is also provided.Type: ApplicationFiled: November 6, 2019Publication date: May 6, 2021Applicants: GM GLOBAL TECHNOLOGY OPERATIONS LLC, KENT STATE UNIVERSITYInventors: John HARDEN, Liang-Chy CHIEN, Kai-Han CHANG
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Publication number: 20210080800Abstract: Liquid crystal lenses of different apertures with suppressed chromatic aberration utilizing twisted vertical alignment configuration are demonstrated. A plurality of substrates are provided with electrodes, including a patterned electrode to generate a lens effect. The liquid crystal material is homeotropically aligned, such as via alignment layers. Setting the ratio between cell thickness and chiral pitch of the cholesteric liquid crystals provides correction of axial chromatic aberrations of electrically-tunable focal lengths in the device.Type: ApplicationFiled: May 18, 2018Publication date: March 18, 2021Inventors: Liang-Chy Chien, Kai-Han Chang, Andril Varanytsia
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Publication number: 20200385634Abstract: A fast flexoelectro-optic switching device containing bimesogen-doped and polymer-stabilized vertical standing helix (PSVSH) in a cholesteric liquid crystal. The PSVSH device exhibits a response time of less than 0.7 millisecond, high contrast and negligible hysteresis which is suitable for applications including blur-free displays, field-sequential color displays and active optical elements.Type: ApplicationFiled: March 9, 2018Publication date: December 10, 2020Inventors: Liang-Chy CHIEN, Vinay JOSHI, Kai-Han CHANG
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Patent number: 10031364Abstract: A polymer-dispersed blue-phase (PDBP) liquid crystal film is formed from a polymer-based latex and blue-phase liquid crystals that are combined using an emulsification process or a polymerization-induced phase separation process. The resultant PDBP liquid crystal film includes droplets formed by the polymer-based latex that encapsulate the blue-phase liquid crystals therein, so as to allow the blue-phase liquid crystals to have a blue phase at room temperature. As such, the PDBP liquid crystal film is conducive for use in manufacturing processes, such as LCD (liquid crystal display) manufacturing processes, while providing desirable optical features, such as field-induced birefringence at low switching voltages.Type: GrantFiled: November 24, 2015Date of Patent: July 24, 2018Assignee: Kent State UniversityInventors: Liang-Chy Chien, Jeoung-Yeon Hwang, Emine Kemiklioglu
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Publication number: 20180059457Abstract: A bistable liquid crystal spatial light modulating (SLM) device (SLM) device utilizes the homeotropic and bubble domain texture change of a cholesteric liquid crystal that is responsive to external stimuli, such as electric voltage, light and pressure. The SLM device is configured to be switched between the two stable textures of the bubble domain texture or the fingerprint texture. In addition, the SLM device may be switched between transparent and light-scattering states by the application of an electric field, light irradiation or physical/mechanical pressure. The light transmission state and the light-scattering states of the present invention are also stable in time at zero voltage, and are reversible upon the application of an external field at a different voltage, frequency or wavelength of light.Type: ApplicationFiled: November 6, 2017Publication date: March 1, 2018Applicant: Kent State UniversityInventors: Liang-Chy Chien, Andrii Varanytsia
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Patent number: 9835923Abstract: A bistable liquid crystal spatial light modulating (SLM) device (SLM) device utilizes the homeotropic and bubble domain texture change of a cholesteric liquid crystal that is responsive to external stimuli, such as electric voltage, light and pressure. The SLM device is configured to be switched between the two stable textures of the bubble domain texture or the fingerprint texture. In addition, the SLM device may be switched between transparent and light-scattering states by the application of an electric field, light irradiation or physical/mechanical pressure. The light transmission state and the light-scattering states of the present invention are also stable in time at zero voltage, and are reversible upon the application of an external field at a different voltage, frequency or wavelength of light.Type: GrantFiled: July 21, 2015Date of Patent: December 5, 2017Assignee: Kent State UniversityInventors: Liang-Chy Chien, Andrii Varanytsia
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Publication number: 20170102577Abstract: Electro-optical devices utilizing alternative transparent conductive oxide (TCO) layers, such as aluminum zinc oxide (AZO) and gallium zinc oxide (GZO), and indium composites, are able to replace traditional indium-tin-oxide (ITO) TCOs. As a result, the electro-optical devices of the embodiments of the present invention are able to achieve high operating performance, including: high light transmittance, fast response times and low applied voltages, which are comparable to those of electro-optical devices using (ITO) coated substrates, while also being low-cost.Type: ApplicationFiled: October 10, 2016Publication date: April 13, 2017Applicant: Kent State UniversityInventors: Liang-Chy Chien, Libo Weng, Andrii Varanytsia
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Patent number: 9376619Abstract: A surface polymer-assisted vertically aligned (SPA-VA) liquid crystal (LC) cell has a surface alignment layer of surface localized polymer nano spikes capable of controlling the pretilt angle of liquid crystal molecules and ensuring fast switching characteristics. The deposition of the polymer nanospikes as a part of the alignment layer is achieved by polymerizing a small amount of a reactive monomer in vertically aligned liquid crystal with or without an applied voltage. Due to the alignment of liquid crystal molecules by the surface alignment layers, the polymerized polymer acts as an internal surface to modify and control the field-induced reorientation of the liquid crystal molecules. The SPA-VA LC cell realizes a stable alignment and the considerable advantage of the formation of polymer spikes via UV irradiation on both substrates of the cell. Furthermore, the switch-off of a SPA-VA is fast due to the enhanced surface anchoring strength by the surface-localized polymer nano spikes.Type: GrantFiled: February 15, 2011Date of Patent: June 28, 2016Assignee: KENT STATE UNIVERSITYInventors: Liang-Chy Chien, Volodymyr Borshch, Jeoung-Yeon Hwang
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Publication number: 20160170118Abstract: This invention is related to electro-optical devices and active retardation films that can modulate one or more of the amplitude, phase or polarization of an electromagnetic wave. The active retardation film is based on a polymer-stabilized cholesteric liquid crystal (PS-CLC) in a cell with helix lying in the plane parallel to the substrates at zero voltage. An electro-optical cell to observe such electro-optical effect comprises of two substrates with transparent conductive electrodes coated inside the cell and the substrates are coated with alignment layers whereby the alignment layers are treated to provide uniform alignment of the cholesteric helix. Polymerizing a small amount of a reactive monomer in the cholesteric stabilize the ULH texture at zero voltage. The electro-optical effect is achieved by applying a bias field to induce an in-plane rotation of cholesteric helical initially parallel to one of a pair of polarizers crossed at 90 degrees.Type: ApplicationFiled: December 15, 2015Publication date: June 16, 2016Inventors: Liang-Chy Chien, Andrii Varyantsia
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Publication number: 20160085095Abstract: A polymer-dispersed blue-phase (PDBP) liquid crystal film is formed from a polymer-based latex and blue-phase liquid crystals that are combined using an emulsification process or a polymerization-induced phase separation process. The resultant PDBP liquid crystal film includes droplets formed by the polymer-based latex that encapsulate the blue-phase liquid crystals therein, so as to allow the blue-phase liquid crystals to have a blue phase at room temperature. As such, the PDBP liquid crystal film is conducive for use in manufacturing processes, such as LCD (liquid crystal display) manufacturing processes, while providing desirable optical features, such as field-induced birefringence at low switching voltages.Type: ApplicationFiled: November 24, 2015Publication date: March 24, 2016Applicant: Kent State UniversityInventors: Liang-Chy Chien, Jeoung-Yeon Hwang, Emine Kemiklioglu
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Publication number: 20160018681Abstract: A bistable liquid crystal spatial light modulating (SLM) device (SLM) device utilizes the homeotropic and bubble domain texture change of a cholesteric liquid crystal that is responsive to external stimuli, such as electric voltage, light and pressure. The SLM device is configured to be switched between the two stable textures of the bubble domain texture or the fingerprint texture. In addition, the SLM device may be switched between transparent and light-scattering states by the application of an electric field, light irradiation or physical/mechanical pressure. The light transmission state and the light-scattering states of the present invention are also stable in time at zero voltage, and are reversible upon the application of an external field at a different voltage, frequency or wavelength of light.Type: ApplicationFiled: July 21, 2015Publication date: January 21, 2016Applicant: KENT STATE UNIVERSITYInventors: Liang-Chy Chien, Andrii Varanytsia
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Patent number: 9086596Abstract: A surface-stabilized in-plane switching (SS-IPS) liquid crystal (LCD) cell includes a pair of spaced substrates that include alignment layers disposed thereon. The alignment layers are treated to define a first director orientation. Disposed between the alignment layers is a liquid crystal material that contains polymer fibrils that are disposed upon each of the alignment layers. The polymer fibrils serve to maintain the alignment of the liquid crystal molecules in the first director orientation when no voltage is applied to the LCD cell via interdigitated electrodes disposed upon the alignment layers, thus improving the dynamic response of the SS-IPS LCD cell.Type: GrantFiled: June 27, 2013Date of Patent: July 21, 2015Assignee: Kent State UniversityInventors: Liang-Chy Chien, Jeoung-Yeon Hwang
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Patent number: 9085730Abstract: The invention provides a liquid crystal (LC) composition, a LC cell thereof, and a LC device thereof. The LC composition comprises (i) a mixture of two or more nematic liquid crystals, and (ii) at least one chiral dopant. The mixture of the liquid crystals can exist in a blue phase within a temperature range of from about 12-60° C. such as 21-28° C. The LC device can be a blue phase mode liquid crystal display (BPLCD) based on such a room-temperature blue phase LC. The BPLCD requires no alignment, and it exhibits merits such as a fast switching time (e.g. sub-millisecond), a low switching voltage and a large field-induced birefringence, among others.Type: GrantFiled: June 16, 2010Date of Patent: July 21, 2015Assignee: Kent State UniversityInventors: Liang-Chy Chien, Lu Lu, Jeoung Yeon Hwang
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Patent number: 8964161Abstract: The present invention provides an electro-optical device comprising a cell of polymer-stabilized blue phase (PSBP) liquid crystal under an electrical field and a method of controlling the reflection and transmission of an incident electromagnetic radiation such as visible light, by way of controlling the electrical field. The invention exhibits merits such as cost-effectiveness; simpler manufacturability due to the removal of requirements of polarizer and color filter; and fast switching, among others.Type: GrantFiled: June 16, 2010Date of Patent: February 24, 2015Assignee: Kent State UniversityInventors: Liang-Chy Chien, Shin-Ying Lu