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).

  • Patent number: 10031364
    Abstract: 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: Grant
    Filed: November 24, 2015
    Date of Patent: July 24, 2018
    Assignee: Kent State University
    Inventors: Liang-Chy Chien, Jeoung-Yeon Hwang, Emine Kemiklioglu
  • Publication number: 20180059457
    Abstract: 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: Application
    Filed: November 6, 2017
    Publication date: March 1, 2018
    Applicant: Kent State University
    Inventors: Liang-Chy Chien, Andrii Varanytsia
  • Patent number: 9835923
    Abstract: 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: Grant
    Filed: July 21, 2015
    Date of Patent: December 5, 2017
    Assignee: Kent State University
    Inventors: Liang-Chy Chien, Andrii Varanytsia
  • Publication number: 20170102577
    Abstract: 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: Application
    Filed: October 10, 2016
    Publication date: April 13, 2017
    Applicant: Kent State University
    Inventors: Liang-Chy Chien, Libo Weng, Andrii Varanytsia
  • Patent number: 9376619
    Abstract: 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: Grant
    Filed: February 15, 2011
    Date of Patent: June 28, 2016
    Assignee: KENT STATE UNIVERSITY
    Inventors: Liang-Chy Chien, Volodymyr Borshch, Jeoung-Yeon Hwang
  • Publication number: 20160170118
    Abstract: 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: Application
    Filed: December 15, 2015
    Publication date: June 16, 2016
    Inventors: Liang-Chy Chien, Andrii Varyantsia
  • Publication number: 20160085095
    Abstract: 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: Application
    Filed: November 24, 2015
    Publication date: March 24, 2016
    Applicant: Kent State University
    Inventors: Liang-Chy Chien, Jeoung-Yeon Hwang, Emine Kemiklioglu
  • Publication number: 20160018681
    Abstract: 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: Application
    Filed: July 21, 2015
    Publication date: January 21, 2016
    Applicant: KENT STATE UNIVERSITY
    Inventors: Liang-Chy Chien, Andrii Varanytsia
  • Patent number: 9086596
    Abstract: 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: Grant
    Filed: June 27, 2013
    Date of Patent: July 21, 2015
    Assignee: Kent State University
    Inventors: Liang-Chy Chien, Jeoung-Yeon Hwang
  • Patent number: 9085730
    Abstract: 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: Grant
    Filed: June 16, 2010
    Date of Patent: July 21, 2015
    Assignee: Kent State University
    Inventors: Liang-Chy Chien, Lu Lu, Jeoung Yeon Hwang
  • Patent number: 8964161
    Abstract: 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: Grant
    Filed: June 16, 2010
    Date of Patent: February 24, 2015
    Assignee: Kent State University
    Inventors: Liang-Chy Chien, Shin-Ying Lu
  • Publication number: 20140002781
    Abstract: 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: Application
    Filed: June 27, 2013
    Publication date: January 2, 2014
    Applicant: KENT STATE UNIVERSITY
    Inventors: Jeoung-Yeon Hwang, Liang-Chy Chien
  • Publication number: 20130321754
    Abstract: The present invention comprises a fumed metal-oxide gel, such as fumed silica gel, that is dispersed into a blue-phase liquid crystal. Adding the fumed silica nanoparticles in blue-phase media leads to the broadening of the blue-phase temperature range and reduces the switching voltage. Additionally, the polarity-controlled nanoparticles of the fumed silica enable the stabilization of thermal-sensitive Bragg reflection property of the blue-phase liquid crystals, which allows their use in active optical elements and fast-switching LCDs.
    Type: Application
    Filed: May 30, 2013
    Publication date: December 5, 2013
    Inventors: Liang-Chy Chien, Jeoung-Yeon Hwang
  • Patent number: 8580144
    Abstract: A composition including nanocomposites formed from blue phase liquid crystals that are stabilized with dopants and nanorods such as metallic nanorods and/or carbon nanotubes. Devices including the compositions are disclosed that provide increases temperature ranges as well as reduction in threshold voltage and turn on voltage, in addition to the inherent blue phase liquid crystal properties of sub-millisecond response time in the field induced Kerr effect.
    Type: Grant
    Filed: April 6, 2012
    Date of Patent: November 12, 2013
    Assignee: Kent State University
    Inventors: Liang-Chy Chien, Jeoung Yeon Hwang, Jenny-Marie Wong
  • Patent number: 8564750
    Abstract: A method of preparing liquid crystal alignment films using an inkjet printer to control liquid crystal alignment is disclosed. The alignment ink is formulated from a single alignment material or combination of alignment materials to realize desired pretilt angle. The alignment films can be applied with designed patterns of alignment films of different pretilt angle on at least one substrate to achieve pattern-aligned liquid crystal devices.
    Type: Grant
    Filed: July 3, 2008
    Date of Patent: October 22, 2013
    Assignee: Kent State University
    Inventors: Liang-Chy Chien, Jeoung Yeon Hwang
  • Publication number: 20130027639
    Abstract: 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: Application
    Filed: February 15, 2011
    Publication date: January 31, 2013
    Applicant: KENT STATE UNIVERSITY
    Inventors: Liang-Chy Chien, Volodymyr Borshch, Jeoung-Yeon Hwang
  • Publication number: 20120262662
    Abstract: A composition including nanocomposites formed from blue phase liquid crystals that are stabilized with dopants and nanorods such as metallic nanorods and/or carbon nanotubes. Devices including the compositions are disclosed that provide increases temperature ranges as well as reduction, in threshold voltage and turn on voltage, in addition to the inherent blue phase liquid crystal properties of sub-millisecond response time in the field induced Kerr effect.
    Type: Application
    Filed: April 6, 2012
    Publication date: October 18, 2012
    Applicant: KENT STATE UNIVERSITY
    Inventors: Liang-Chy Chien, Jeoung Yeon Hwang, Jenny-Marie Wong
  • Patent number: 8264639
    Abstract: The present invention provides liquid crystal devices comprised of a composite of an internal polymer network localized on the substrate surfaces and short-pitch dual-frequency switchable cholesteric liquid crystal that operate in two different modes including in-plane switching (amplitude modulation) and out-of-plane switching (phase modulation). The invention further provides a method of making a liquid crystal device demonstrating uniform lying helical axis where the device comprises a composite of an internal spatially ordered polymer network localized by in-situ photo-polymerization at the surface of the substrate. The invention can be used for flat panel displays, as well as spatial light modulators for applications such as optical waveguides, optical beam scanners, computer-generated holograms, and adaptive optics.
    Type: Grant
    Filed: November 4, 2009
    Date of Patent: September 11, 2012
    Assignee: Kent State University
    Inventors: Liang-Chy Chien, Lei Shi, Sang Hwa Kim
  • Patent number: 8081272
    Abstract: In a preparation method, a chiral or cholesteric liquid crystal, a photoreactive monomer, and a photoinitiator are disposed in a liquid crystal cell. A principal surface of the liquid crystal cell is illuminated with ultraviolet light selected to have a non-uniform ultraviolet light intensity profile in the liquid crystal cell. The illuminating cooperates with the photoinitiator to polymerize at least a portion of the photoreactive monomer near the principal surface to generate a polymer network having a density corresponding to the non-uniform ultraviolet light intensity profile. The polymer network biases the liquid crystal toward a selected helical alignment direction. In some embodiments, the illuminating includes illuminating with first and second ultraviolet light intensity profiles to produce surface and volume polymer network components.
    Type: Grant
    Filed: February 25, 2009
    Date of Patent: December 20, 2011
    Assignees: Kent State University
    Inventors: Lachezar Komitov, Liang-Chy Chien, Sang Hwa Kim
  • Publication number: 20110007260
    Abstract: 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 (HPLCD) based on such a room-temperature blue phase LC. The HPLCD 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: Application
    Filed: June 16, 2010
    Publication date: January 13, 2011
    Inventors: Liang-Chy Chien, Lu Lu, Jeoung Yeon Hwang