Patents by Inventor Yao-Dong Ma

Yao-Dong Ma 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: 20050052595
    Abstract: The present invention relates to a circular polarizer, more specifically, to a diffusively reflective circular polarizer (DRCP), which is characterized by broadband reflection and transmission over a hemispheric viewing angle. A thermo phase separation process of a cholesteric liquid crystal polymer system creates the DRCP film. As a multi-functional optical material, the DRCP film combines the merits of polarizer, reflector and diffuser to form an all-in-one component in the electro-optical industry. Moreover, since the novel film has a “silver white” appearance and super “hiding power”, it will initiate many other applications.
    Type: Application
    Filed: September 8, 2003
    Publication date: March 10, 2005
    Inventor: Yao-Dong Ma
  • Patent number: 6757039
    Abstract: This invention relates to paper white cholesteric displays employing a reflective elliptical polarizer. In the reflective mode, the paper white ON state is achieved by a reflective elliptical polarizer in display's planar texture area; and the black OFF state is obtained by cholesteric's depolarization effect and polarizer's filtration effect in display's focal conic texture area. In the transmissive mode, on the other hand, the paper white ON state is created by a back lighting projected onto the focal conic texture area; and the black OFF state is realized in the cholesteric planar texture area. The reflective elliptical polarizer with a broadband reflection and high polarization efficiency delivers a bright neutral white color to both the reflective and transmissive mode cholesteric displays. The reflective elliptical polarizer also provides a solution to the transflective display where the high efficiency front-lit mode and the back-lit mode can be converted automatically.
    Type: Grant
    Filed: June 17, 2002
    Date of Patent: June 29, 2004
    Inventor: Yao-Dong Ma
  • Publication number: 20030231269
    Abstract: This invention relates to reflective cholesteric displays without using Bragg reflection. The helical pitch of the cholesteric liquid crystals may or may not be tuned in a visible wavelength, but its Bragg reflection will never be displayed. An elliptical polarizer with properly designed retardation and lamination positioned at the front of the display will be able to eliminate the Bragg reflection over a large viewing cone. The function of the display cell structure is merely a light shutter to switch the incident light ON and OFF. In the black-and-white display mode, the white state is achieved from the metal reflection in the cholesteric planar texture area; and the black state is obtained by cholesteric's depolarization effect and polarizer's filtration effect in the cholesteric focal conic texture area.
    Type: Application
    Filed: June 15, 2002
    Publication date: December 18, 2003
    Inventor: Yao-Dong Ma
  • Publication number: 20030231266
    Abstract: This invention relates to paper white cholesteric displays employing a reflective elliptical polarizer. In the reflective mode, the paper white ON state is achieved by a reflective elliptical polarizer in display's planar texture area; and the black OFF state is obtained by cholesteric's depolarization effect and polarizer's filtration effect in display's focal conic texture area. In the transmissive mode, on the other hand, the paper white ON state is created by a back lighting projected onto the focal conic texture area; and the black OFF state is realized in the cholesteric planar texture area. The reflective elliptical polarizer with a broadband reflection and high polarization efficiency delivers a bright neutral white color to both the reflective and transmissive mode cholesteric displays. The reflective elliptical polarizer also provides a solution to the transflective display where the high efficiency front-lit mode and the back-lit mode can be converted automatically.
    Type: Application
    Filed: June 17, 2002
    Publication date: December 18, 2003
    Inventor: Yao-Dong Ma
  • Publication number: 20030160923
    Abstract: The present invention relates to a liquid crystal display, more specifically, relates to a full color cholesteric display employing circularly polarized micro-color filter which is composed of polymeric cholesteric thin film. The display has a long time memory and excellent characteristics of brightness and contrast. A built-in cholesteric color filter structure provides a full color gamut of circular polarization. A cholesteric liquid crystal cell structure, as a circular polarization modulator, provides optical ON and OFF states respectively with its one texture as a circular polarizer and the other texture as a depolarizer. Both of those two textures are electric field controllable.
    Type: Application
    Filed: February 19, 2002
    Publication date: August 28, 2003
    Inventor: Yao-Dong Ma
  • Publication number: 20030151580
    Abstract: The present invention relates to cholesteric liquid crystal display, especially, to a passive motion video cholesteric liquid crystal display. The display provides not only a video speed with full color moving picture when supplying electric field, but also a video-rate response, long-term memory and high-resolution image in the absence of electric field. The field-induced nematic texture has been denoted as an optical state and cholesteric focal conic texture as another optical state during the video rate display mode. And the cholesteric planar texture has been denoted as an optical state and cholesteric focal conic texture as another during the storage-type display mode. The video rate addressing is accomplished by a narrow pulse scanning at a seed of 30-60 microseconds per row. The novel display mode and driving means deliver a passive display with a property that the display not only looks like a TV or a computer monitor dynamically but also like a permanent picture or prints statically.
    Type: Application
    Filed: February 11, 2002
    Publication date: August 14, 2003
    Inventor: Yao-Dong Ma
  • Publication number: 20030122752
    Abstract: A localized driving means for cholesteric liquid crystal display comprises a high erasing pulse; a low addressing pulse and a series bias voltage pulses with its amplitude not less than a threshold voltage from planar to focal conic structure. The erasing pulse and the addressing pulse, superimposed to the bias pulses, are applied to a predetermined location at the same time, whereby the unstable planar state and the unstable focal conic state are displayed simultaneously in at least a partial area of the display during the addressing; whereby an stable planar state and an stable focal conic state are displayed simultaneously in at least a partial area of the display by the end of the addressing process.
    Type: Application
    Filed: January 3, 2002
    Publication date: July 3, 2003
    Inventor: Yao-Dong Ma
  • Publication number: 20030085863
    Abstract: A low power consumption and fast speed driving means for cholesteric liquid crystal displays (ChLCDs). The novelty of the driving means is based upon the dynamic relaxation process of ChLCD from field induced nematic phase to the stable cholesteric phases, during which both the planar state or focal conic state can be formed simultaneously and the information can also be erased and addressed simultaneously. The driving means only consists of one erasing pulse that is higher than the phase change voltage and one addressing pulse that is lower than the phase change voltage.
    Type: Application
    Filed: November 3, 2001
    Publication date: May 8, 2003
    Inventor: Yao-Dong Ma
  • Patent number: 6344887
    Abstract: This invention is related to a full spectrum reflective or tranmissive black-and-white cholesteric liquid crystal display. The white state is realized by a full gamut of light reflection or transmission in the display's planar texture, and the black state is created by cholesterics' scattering type depolarization effect and polarizer's filtration effect in the display's focal conic texture. It has been discovered that the scattering depolarization effect and multi-filtration process can generate a black dark state, the optical “off” state in focal conic texture of cholesteric liquid crystals. In the dark-and-white cholesterics display can be easily upgraded to a full color display by means of micro-color filter structure in both front and back illuminating systems.
    Type: Grant
    Filed: September 10, 1999
    Date of Patent: February 5, 2002
    Inventors: Yao-Dong Ma, Calvin Ma
  • Patent number: 6285434
    Abstract: A substrate for a multi-color liquid crystal display (LCD), an LCD having the substrate, and methods of manufacturing the substrate and the LCD. In one embodiment, the substrate includes: (1) a substantially planar base and (2) a cell wall structure, located on a surface of the base, that defines at least first and second sets of independent cells having corresponding independent fluid fill ports when the cell wall structure is bonded to an opposing substrate.
    Type: Grant
    Filed: February 20, 1998
    Date of Patent: September 4, 2001
    Assignee: Advanced Display Systems, Inc.
    Inventors: Yao Dong Ma, Bao-Gang Wu, Jianmi Gao, Jianan Hou, Yong-Jing Wang, Qihui J. Zhang
  • Patent number: 6020941
    Abstract: A stereographic liquid crystal display (LCD) and various methods of manufacturing and operating such stereographic LCD. In one embodiment, the LCD includes: (1) first and second substrates having a cell wall structure located in an interstice therebetween that defines first and second sets of independent cells in the LCD; (2) a first controllable liquid crystal (CLC) material located in the first plurality of independent cells, the first CLC material selectively exhibiting an "on" state and an "off" state and having a first polarity when in the "on" state; and (3) a second CLC material located in the second plurality of independent cells, the second CLC material selectively exhibiting an "on" state and an "off" state and having a second polarity when in the "on" state.
    Type: Grant
    Filed: February 12, 1998
    Date of Patent: February 1, 2000
    Assignee: Advanced Display Systems, Inc.
    Inventor: Yao-Dong Ma
  • Patent number: 5949513
    Abstract: Methods of manufacturing a liquid crystal display ("LCD"); specifically, a multi-color LCD, e.g., a red-green-blue ("RGB") LCD. The methods include the steps of: (1) depositing a twist agent on a first substrate, the twist agent becoming an in situ twist agent, (2) bringing a second substrate into proximity with the first substrate to form at least one interstitial region between the second and first substrates, (3) introducing liquid crystal ("LC") having an initial pitch into the at least one interstitial region proximate the in situ twist agent and (4) stimulating the LC and the in situ twist agent to cause the LC and the in situ twist agent to mix in situ, the in situ twist agent changing the initial pitch of the LC.
    Type: Grant
    Filed: October 13, 1998
    Date of Patent: September 7, 1999
    Assignee: Advanced Display System, Inc.
    Inventors: Yao-Dong Ma, Bao-Gang Wu
  • Patent number: 5889566
    Abstract: A light modulating apparatus containing cholesteric liquid crystals capable of indefinite zero field retention of optical images, including full color and complete gray scale capability, is described. This invention is predicated on establishment of zero field multistable liquid crystal domains representing a continuous distribution of states ranging from the highly reflective planar to the light-scattering focal-conic structures. The zero field multistable domain structure stability is achieved by controlling solid surface-liquid crystal boundary interactions to provide essential equalization of the total system energy of each of the domain structures. This is the first time this equalization, and thus zero field multistability, has been achieved without the use of a polymer gel addition to create rigid polydomains in the liquid crystal mix.
    Type: Grant
    Filed: April 17, 1997
    Date of Patent: March 30, 1999
    Assignee: Advanced Display Systems, Inc.
    Inventors: Bao-Gang Wu, Jianmi Gao, Hongxi Zhou, Yao-Dong Ma
  • Patent number: 5825451
    Abstract: Methods of manufacturing a liquid crystal display ("LCD"); specifically, a multi-color LCD, e.g., a red-green-blue ("RGB") LCD. The methods include the steps of: (1) depositing a twist agent on a first substrate, the twist agent becoming an in situ twist agent, (2) bringing a second substrate into proximity with the first substrate to form at least one interstitial region between the second and first substrates, (3) introducing liquid crystal ("LC") having an initial pitch into the at least one interstitial region proximate the in situ twist agent and (4) stimulating the LC and the in situ twist agent to cause the LC and the in situ twist agent to mix in situ, the in situ twist agent changing the initial pitch of the LC.
    Type: Grant
    Filed: October 17, 1997
    Date of Patent: October 20, 1998
    Assignee: Advanced Display Systems, Inc.
    Inventors: Yao-Dong Ma, Bao-Gang Wu
  • Patent number: 5796454
    Abstract: A cholesteric liquid crystal display ("LCD") and methods of operating and manufacturing the LCD. The LCD includes: (1) a controllable cholesteric liquid crystal (CLC) located between first and second substrates, the controllable CLC selectively exhibiting an "on" state and an "off" state and having a circular polarity of a predetermined handedness when the controllable CLC is in the "on" state and (2) a circular polarizer, located proximate the first substrate and having a circular polarity of a particular handedness, that cooperates with the controllable CLC to increase the difference between the relative brightness of the "on" state and the "off" state, whereby a contrast ratio of the cholesteric LCD is increased.
    Type: Grant
    Filed: December 4, 1996
    Date of Patent: August 18, 1998
    Assignee: Advanced Display Systems, Inc.
    Inventor: Yao-Dong Ma
  • Patent number: 5661533
    Abstract: Surfactant-containing multistable cholesteric liquid crystal displays exhibit ultra fast response times with both video speed and gray scale capability.
    Type: Grant
    Filed: May 19, 1995
    Date of Patent: August 26, 1997
    Assignee: Advanced Display Systems, Inc.
    Inventors: Bao-Gang Wu, Hongxi Zhou, Yao-Dong Ma
  • Patent number: 5625477
    Abstract: A light modulating apparatus containing cholesteric liquid crystals capable of indefinite zero field retention of optical images, including full color and complete gray scale capability, is described. This invention is predicated on establishment of zero field multistable liquid crystal domains representing a continuous distribution of states ranging from the highly reflective planar to the light-scattering focal-conic structures. The zero field multistable domain structure stability is achieved by controlling solid surface-liquid crystal boundary interactions to provide essential equalization of the total system energy of each of the domain structures. This is the first time this equalization, and thus zero field multistability, has been achieved without the use of a polymer gel addition to create rigid polydomains in the liquid crystal mix.
    Type: Grant
    Filed: April 11, 1994
    Date of Patent: April 29, 1997
    Assignee: Advanced Display Systems, Inc.
    Inventors: Bao-Gang Wu, Jianmi Gao, Hongxi Zhou, Yao-Dong Ma
  • Patent number: 5056898
    Abstract: A reverse mode liquid crystal light shutter and display device is field-off transparent and field-on non-transparent (i.e., scattering and/or absorbing). The reverse phase mode is obtained by modification of the surface energy of the polymer which encases liquid crystal droplets via reaction of a surfactant, incorporated inside of the LC droplets during droplet formation, within the inside polymer layer. The reverse phase transparent "off" state is achieved by refractive index matching of the average refractive index (.about.n.sub.o) of the LC droplets at electric field off state with the refractive index of the containing polymer materials and by obtaining appropriate droplet size and shape and polymer surface energy to cause the major axis of the liquid crystal molecule to be oriented perpendicular to the substrate surface. The inner surface layer aligns the liquid crystal molecules in an homeotropic manner in a resultant composite multi-layer microcapsulate with a homogeneous material for the capsule skin.
    Type: Grant
    Filed: July 17, 1989
    Date of Patent: October 15, 1991
    Assignee: Polytronix, Inc.
    Inventors: Yao-Dong Ma, Bao-Gong Wu