Cholesteric Reflector Patents (Class 349/115)
  • Patent number: 6580481
    Abstract: The invention provides an information recording/displaying card and an information recording/displaying system using the card in which invisible information can be recorded, the invisible information can be displayed as visible information and visible information can be written/erased as color images at a practical speed. The information recording/displaying card includes a visible information display part and an invisible information recording part. These parts are disposed, for example, on the front and back surfaces of the card, respectively, or arranged side by side on the front or back surface thereof. The visible information display part includes, as a main component, a low molecular weight cholesteric liquid crystal compound having an isotropic phase transition temperature higher than a melting point, so that information can be displayed, written once and erased therein.
    Type: Grant
    Filed: July 2, 1999
    Date of Patent: June 17, 2003
    Assignee: Minolta Co., Ltd.
    Inventors: Hideaki Ueda, Tsuyoshi Nozaki, Shoji Kotani
  • Patent number: 6580482
    Abstract: A reflective-type multi-color display device is capable of obtaining a vivid and bright multi-color display with less display layers, and therefore, with a state where a parallax is decreased and a cost of the device can be reduced. Specifically, the display device of the present invention includes a cell 51 having a display layer 31 comprising a right-handed cholesteric liquid crystal which selects and reflects blue, a cell 53 having a display layer 33 comprising a left-handed cholesteric liquid crystal which selects and reflects green, a cell 57 having a display layer 37 comprising a right-handed cholesteric liquid crystal which selects and reflects yellow and a cell 55 having a display layer 35 comprising a left-handed cholesteric liquid crystal which selects and reflects red, these layers being laminated in this order from the observation side. A color filter 43 which transmits red and absorbs the other color light is provided between the cell 57 and the cell 55.
    Type: Grant
    Filed: November 9, 1999
    Date of Patent: June 17, 2003
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Naoki Hiji, Shigeru Yamamoto, Takehito Hikichi, Teiichi Suzuki
  • Patent number: 6580479
    Abstract: A watch unit having a time-displaying section, including a reflection-type polarizing film 14 disposed on an upper portion or a lower portion of the time-displaying section or a portion comprising a part of the time-displaying section, an optical modulation section which varies the ratio of a transmission axis to a reflection axis of the reflection-type polarizing film 14, and a shutter function to shield a portion of or all of the watch unit having the time-display section by varying the reflection intensity and the transmission intensity in relation to the light incident direction using the reflection-type polarinzing film 14 and the optical modulation section, to enhance the appearance and to improve the versatility of the watch unit.
    Type: Grant
    Filed: March 15, 1999
    Date of Patent: June 17, 2003
    Assignee: Citizen Watch Co., Ltd.
    Inventors: Kanetaka Sekiguchi, Masafumi Ide, Takashi Akiyama, Masami Kikuchi, Yuichi Akiba, Koji Nakagawa, Koichi Hoshino, Takashi Toida
  • Patent number: 6580483
    Abstract: A reflection liquid crystal display device comprising a liquid crystal cell where a liquid crystal layer is provided between two opposed electrode substrates, a reflecting layer, and a cholesteric liquid crystal film, characterized in that the ratio (SCE/SCI) of the specular component excluded-refelctance (SCE) to the specular component included-reflectance (SCI) of the cholesteric liquid crystal film is 15% or more, the wavelenght bandwidth of the cholesteric selective reflection ranges from 30 mm to 150 nm, and the center wavelength of the cholesteric selective reflection is in the visible range of 380-780 nm or in the near-infared range of 800-2000 nm.
    Type: Grant
    Filed: December 21, 2001
    Date of Patent: June 17, 2003
    Assignee: Nippon Mitsubishi Oil Corporation
    Inventors: Shinichiro Suzuki, Shinichi Komatsu, Suzushi Nishimura
  • Patent number: 6577364
    Abstract: A reflective liquid crystal device comprises a polarizer and a mirror between which are disposed several retarder. At least one of the retarders is a variable liquid crystal element whose optic axis is switchable so as to switch the device between a reflective state and a non-reflective state. In the non-reflective state, the total retardance of the retarders between the polariser and the mirror is equal to an odd number of quarter wavelengths for a wavelength at or adjacent the middle of the visible spectrum.
    Type: Grant
    Filed: November 3, 2000
    Date of Patent: June 10, 2003
    Inventors: Martin David Tillin, Michael John Towler, Kirstin Ann Saynor, Sandra Gilmour
  • Patent number: 6573963
    Abstract: An optical body can be formed using cholesteric liquid crystal materials. At least two different coating compositions containing cholesteric liquid crystal material are coated on a substrate. At least a portion of each composition is allowed to interdiffuse to generate a change in pitch along a thickness dimension of the optical body. This optical body can be used, for example, as a reflective polarizer in an optical display.
    Type: Grant
    Filed: February 22, 2001
    Date of Patent: June 3, 2003
    Assignee: 3M InnovativeProperties Company
    Inventors: Andrew John Ouderkirk, John David Munter, Marvin Ray Kammin
  • Patent number: 6573961
    Abstract: Reflective color filters using layers of cholesteric liquid crystals with two different center wavelengths and bandwidths per layer are stacked in two layers to provide colored light for displays. With a two layer stack circularly polarized light of one handedness can be provided. With a two layer stack circulary unpolarized colored light can be provided. With a broadband polarizing filter overlapping other filters in the stack a black matrix can be provided by reflecting all colors and transmitting no light in the overlapping areas. When broadband reflective cholesteric liquid crystals are used two primary colors can be reflected in the same pixel of a display making reflective layers with two reflective portions per layer possible. Color displays having three linear sub-pixels with three primary colors or with four sub-pixels of white, blue, green, and red in a pixel with two colors in a top row and two colors on a bottom row can are made with two colors per layer in two layer stacks.
    Type: Grant
    Filed: May 17, 1999
    Date of Patent: June 3, 2003
    Assignee: Reveo, Inc.
    Inventors: Yingqiu Jiang, Le Li, Aharon Hochbaum, Sameer Vartak, Hristina Galabova, Richard Wiley, Sadeg M. Faris
  • Patent number: 6574044
    Abstract: A polarizer construction is disclosed that includes a reflective polarizer disposed on a first side of the construction to transmit light having one polarization and reflect light having an orthogonal polarization, and one or more colored dichroic polarizers disposed on a second side of the construction. The one or more colored dichroic polarizers are arranged so that when the construction is illuminated from the first side, an observer viewing the construction from the second side will observe a first spectral distribution of visible light, and when the construction is illuminated from the second side, an observer viewing the construction from the second side will observe a second spectral distribution of visible light different from the first spectral distribution. Various display constructions using colored polarizers to achieve color changing and image reversal effects are also disclosed.
    Type: Grant
    Filed: October 25, 1999
    Date of Patent: June 3, 2003
    Assignee: 3M Innovative Properties Company
    Inventors: Hassan Sahouani, Kim Marie Vogel, Keith M. Kotchick, Mark B. O'Neill, William A. Hibbard, Robert S. Moshrefzadeh
  • Patent number: 6573962
    Abstract: This invention has its objects to provide a provide a fine particle arranging method which can accurately control the arrangement of fine particles. This invention is related to a fine particle which comprises arranging method which comprises arranging charged fine particles on a surface of an object, wherein areas having a relatively high electric potential (+(positive)) and areas having a relatively low electric potential (−(negative)) are alternately formed on said surface of the object, electric lines of force are formed based upon the areas having the relatively high electric potential (+(positive)) and the areas having the relatively low electric potential (−(negative)), and the fine particles are arranged at a relatively +(positive) bottom (1) position and/or a relatively −(negative) bottom (2) position of said electric lines of force.
    Type: Grant
    Filed: February 28, 2000
    Date of Patent: June 3, 2003
    Assignees: Sharp Kabushiki Kaisha, Sekisui Chemical Co., Ltd.
    Inventors: Akihiko Tateno, Hiroyuki Nakatani
  • Patent number: 6563553
    Abstract: Disclosed are improved beam steering and scanning devices which utilize cholesteric liquid crystal (CLC) elements arranged in branches to form a logic tree structure. Each branch thereof comprises an active and passive CLC element; the former further comprising a half-wave retarder and an electrode and the latter only the CLC element. Each succeeding branch contains twice as many branches as a preceding branch and, by activating active CLC element electrodes under control of a programmable pulsed source, inputs applied to the first stage of a logic tree are delivered as a scanned line of electromagnetic energy or light to the imaging cells of the last stage of the logic tree. By stacking identical logic tree structures with a laser source for each tree, a flat panel imaging array or display panel is formed in which the transmission intensity losses are minimized.
    Type: Grant
    Filed: January 11, 1999
    Date of Patent: May 13, 2003
    Assignee: Reveo, Inc.
    Inventor: Sadeg M. Faris
  • Publication number: 20030086038
    Abstract: The invention provides a transflective liquid crystal device with superior visibility that is capable of enhancing the brightness of display in a transmissive mode while maintaining the brightness of display in a reflective mode. A transflective liquid crystal device in accordance with the present invention is equipped with a cholesteric reflective layer that is provided on the inner surface side of a color filter substrate (lower substrate) and reflects at least a part of circular polarized light having a predetermined direction of rotation, and an upper substrate elliptic polarized light introducing device to cause elliptic polarized light to enter a liquid crystal layer through an opposing substrate (upper substrate). The twist angle of the liquid crystal layer ranges from 0 to 12° and a &Dgr;n·d value is 0.37±0.05 &mgr;m, or the twist angle of the liquid crystal layer is 130±20° and the &Dgr;n·d value is 0.76±0.05 mm.
    Type: Application
    Filed: October 24, 2002
    Publication date: May 8, 2003
    Applicant: Seiko Epson Corporation
    Inventor: Osamu Okumura
  • Patent number: 6559903
    Abstract: An electro-optical glazing structure having reflection and transparent modes of operation for selectively reflecting and transmitting electromagnetic radiation without absorption, respectively. The electro-optical glazing structure comprising: an electro-optical panel having first and second optical states of operation; a composite broad-band infrared (IR) reflective polarizing filter structure of electrically-passive construction, mounted to the electro-optical panel; and an optical state switching mechanism for switching the electro-optical panel to the first optical state of operation in order to induce the electro-optical glazing structure into the reflection mode of operation, and for switching the electro-optical panel to the second optical state of operation in order to induce the electro-optical glazing structure into the transparent mode of operation.
    Type: Grant
    Filed: February 27, 1998
    Date of Patent: May 6, 2003
    Assignee: Reveo, Inc.
    Inventors: Sadeg M. Faris, Le Li, Jian-Feng Li
  • Publication number: 20030081161
    Abstract: The invention prevents a connection failure arising from an ingress of a conductive material, such as a solder ball, into a cholesteric liquid crystal layer in a liquid crystal display device having the cholesteric liquid crystal layer on a substrate when an electronic component is mounted to be connected to a conductor arranged on the substrate having the cholesteric liquid crystal layer thereon. A liquid crystal display device includes a liquid crystal cell having a liquid crystal layer between an upper substrate and a lower substrate bonded to each other with a sealing member interposed therebetween. First conductors are arranged on the inner surface of the lower substrate and second conductors are arranged on the inner surface of the upper substrate. A transflective layer containing a cholesteric liquid crystal layer is arranged between the lower substrate and the first conductors. Electronic components are mounted on the inner surface of the upper substrate outside the sealing member.
    Type: Application
    Filed: October 24, 2002
    Publication date: May 1, 2003
    Applicant: Seiko Epson Corporation
    Inventor: Kinya Ozawa
  • Publication number: 20030076468
    Abstract: A selectively reflective film and a process for producing the selectively reflective film, comprising the steps of forming on a substrate, a layer of a liquid crystal composition comprising a liquid crystal compound, a photoreactive chiral compound and a polymerization initiator; irradiating the layer with a first light to establish a distribution of exposure in the liquid crystal composition; raising the temperature of the liquid crystal composition layer to transform the composition into a liquid crystal state, thereby forming an area where selective reflection is attained in accordance with the distribution of exposure; and irradiating the liquid crystal composition with a second light to cause polymerization or cross-linking and thereby harden the composition.
    Type: Application
    Filed: May 28, 2002
    Publication date: April 24, 2003
    Applicant: FUJI PHOTO FILM CO., LTD.
    Inventor: Mitsuyoshi Ichihashi
  • Publication number: 20030076467
    Abstract: A transflective liquid crystal display comprises a top plate comprising a transparent electrode; a bottom plate bonded to the bottom plate, the bottom plate comprising transflective electrodes of aluminum nitride; a liquid crystal layer interposed between the top plate and the bottom plate; and a light source behind the bottom plate. The transflective electrodes reflect incident ambient light and transmit light emitted by the light source. In the liquid crystal display according to the present invention, the transflective electrodes of aluminum nitride replace conventional transparent pixel electrodes such that an image is generated by the transflective liquid crystal display when either ambient light is incident on the surface of the top plate or when light is generated by the light source.
    Type: Application
    Filed: October 19, 2001
    Publication date: April 24, 2003
    Applicant: CHI MEI OPTOELECTRONICS CORP.
    Inventor: Cheng Chi Wang
  • Patent number: 6549254
    Abstract: An optical device (20) is provided using at least one film (23) of cholesteric liquid crystal to reflect at least one predetermined wavelength band from an incident light. This device is characterized in that a non zero birefringence gradient is present in a portion or the entire thickness of said film. The gradient may be obtained in particular by superposing layers (24a-24j) having increasing or decreasing respective birefringence coefficients. The birefringence gradient has the effect of removing the lateral bands of the reflection spectrum, hence making the color of the reflected light more brilliant and more saturated. The effect is particularly advantageous in the case of the color red, for which the lateral band located on the yellow side is perceived strongly by the human eye.
    Type: Grant
    Filed: August 3, 2000
    Date of Patent: April 15, 2003
    Assignee: Asulab S.A.
    Inventors: Joachim Grupp, Peter Kipfer, Toralf Scharf, Christian Bohley, Rolf Klappert, Hans Peter Herzig
  • Publication number: 20030067571
    Abstract: A cholesteric liquid crystal display (LCD) having a reduced dependency between viewing angle and color is achieved by the addition of a weak diffuser to the front surface of the liquid crystal material. The diffuser diffuses both light incident on the surface of the liquid crystal material and light reflected from the liquid crystal material over a wide range of angles. Thus, at any one viewing angle a viewer will observe light that was incident on the display and reflected from it over a wide range of angles. As well as reducing the dependency between viewing angle and color, the addition of the diffuser broadens the range of wavelengths of light reflected by the LC material when it is in a reflective state.
    Type: Application
    Filed: July 9, 2002
    Publication date: April 10, 2003
    Applicant: International Business Machines Corporation
    Inventor: Anthony Cyril Lowe
  • Publication number: 20030063245
    Abstract: An optical body includes a) first particles comprising a first cholesteric liquid crystal material and b) a second cholesteric liquid crystal material. The first particles and the second cholesteric liquid crystal material form a structure where the first cholesteric liquid crystal material has a pitch that is different than the second cholesteric liquid crystal material. In one example, the second cholesteric liquid crystal material is in the form of second particles. In another example, the first particles are dispersed in a matrix of the second cholesteric liquid crystal material. In other examples, the optical body has more than one layer. In addition, one or more additional cholesteric liquid crystal materials can be used in the optical body. These optical bodies can be used as a reflective polarizer and can be used in a display.
    Type: Application
    Filed: September 21, 2001
    Publication date: April 3, 2003
    Inventors: Christopher C. Bowley, Ebihara Ikuko, Gregory Edward Gilligan, Richard John Pokorny, Marc Dudley Radcliffe, Prabhakara Satyauolu Rao, Philip Edwin Watson
  • Patent number: 6538775
    Abstract: A multicolored reflection liquid crystal display device includes a pair of substrates having a reflective holographic polymer dispersed liquid crystal (H-PDLC) film disposed therebetween. The H-PDLC film contains at least two different reflection gratings capable of reflecting two different wavelengths of light. A multicolored reflection H-PDLC is obtained by simultaneously illuminating a plurality of regions of a film comprised of a mixture of a liquid crystal and a photo-polymerizable monomer with a plurality of holographic light patterns capable of providing liquid crystal layers of different spacings so as to obtain different reflection gratings in each of the regions. A mask is placed between each of the laser light beams and the film to form a pattern of light and dark regions on the film. Each mask is positioned such that at least one light region of a first beam pair coincides with at least one dark region of a second beam pair within the film.
    Type: Grant
    Filed: September 16, 1999
    Date of Patent: March 25, 2003
    Assignee: Reveo, Inc.
    Inventors: Christopher C. Bowley, Adam K. Fontecchio, Jaujeng Lin, Gregory P. Crawford, Sadeg M. Faris, Le Li
  • Patent number: 6532052
    Abstract: The present invention is directed to a cholesteric liquid crystal display that includes a homogeneous alignment surface effective to provide increased brightness, low focal conic reflectance and/or reflected light treat is to a significant degree circularly polarized. The homogeneous alignment surface substantially homogeneously aligns the liquid crystal director adjacent thereto. The homogeneous alignment surface may be disposed on one or both sides of a cell of the display. In the case of a cell in which the homogeneous alignment surface is disposed on only one side, the substrate with the inhomogeneous alignment surface may be upstream or downstream of the substrate with the homogeneous alignment surface relative to a direction of incident light. Also included especially in the case of a cell that has the homogeneous alignment surface on both sides is the use of a polarizer to provide very good brightness and low focal conic reflectance.
    Type: Grant
    Filed: August 23, 1999
    Date of Patent: March 11, 2003
    Assignee: Kent Displays, Inc.
    Inventors: Asad A. Khan, Xiao-Yang Huang, J. William Doane, Gene A. Miceli, Donald J. Davis
  • Patent number: 6518944
    Abstract: The present invention is directed to an integrated, reflective bistable, cholesteric liquid crystal display and solar cell assembly providing electrical energy to power display electronics. The liquid crystal display includes the layer of cholesteric liquid crystal material sandwiched between first and second transparent substrates. An inner surface of the first substrate and an inner surface of the second substrate bound the layer of liquid crystal material and the first substrate is closest to a viewer of the display. A first set of conductive electrodes is disposed on the inner surface of the first substrate and a second set of conductive electrodes is disposed on the inner surface of the second substrate. Display driver circuitry is electrically coupled to the first and the second sets of conductive electrodes for generating desired voltage differentials between electrodes of the first set of conductive electrodes and electrodes of the second set of conductive electrodes.
    Type: Grant
    Filed: October 25, 1999
    Date of Patent: February 11, 2003
    Assignee: Kent Displays, Inc.
    Inventors: J. William Doane, Nick M. Miller, IV, Donald James Davis
  • Publication number: 20030020855
    Abstract: A cholesteric liquid crystal (CLC) color filter layer for reflective LCD device includes an additional blue CLC color filter in the red and/or green CLC color filter to increase a color temperature. Since the additional blue CLC color filter is formed using ultraviolet light when forming the blue CLC color filter, additional manufacturing processes for the additional blue CLC color filter are not required. Furthermore, since the color temperature of output light increases according to the CLC color filter layer of the present invention, the high resolution is obtained in image display. Alternatively, the color temperature can be adjustable by way of forming an additional red and/or green CLC color filter in the blue CLC color filter.
    Type: Application
    Filed: December 27, 2001
    Publication date: January 30, 2003
    Inventor: Joun Ho Lee
  • Patent number: 6507380
    Abstract: A polarizer 130 is provided on the upper side of a TN liquid crystal 140, and a light scattering layer 150, a polarization separator 160, a polarizer 170 and a light source 190 are provided on the lower side of the TN element 140. The polarized light separator 160 causes a linear polarized light component in the direction of a transmission axis of light incident from above to be transmitted, and reflects a linear polarized light component thereof in the direction of a reflection axis orthogonal thereto. Under external light, it becomes white in a voltage non-application portion 120, and it becomes dark in a voltage application portion 110. Under light source light, it becomes dark in the voltage non-application portion 120, and it becomes light in the voltage application portion 110.
    Type: Grant
    Filed: March 25, 1999
    Date of Patent: January 14, 2003
    Assignee: Seiko Epson Corporation
    Inventor: Chiyoaki Iijima
  • Publication number: 20020196397
    Abstract: A method of producing a laminated optical film constituted by a laminate of a plurality of optical films different in area, the method including the steps of: laminating an optical film (B) having a plurality of rectangular holes parallel to one another, on at least one surface of an optical film (A) to thereby form a laminate; and cutting the laminate into a plurality of chips to thereby obtain laminated optical films.
    Type: Application
    Filed: June 5, 2002
    Publication date: December 26, 2002
    Applicant: NITTO DENKO CORPORATION
    Inventors: Naoki Takahashi, Satoru Kawahara, Shoji Sugiura, Takeyuki Ashida, Takio Imai
  • Publication number: 20020180915
    Abstract: A wavelength-selecting optical element includes a cholesteric layer that reflects or transmits either of a right-handed circularly polarized light component and a left-handed circularly polarized light component in a selected wavelength band of an incident light; and a diffusing layer disposed on the exit side of the cholesteric layer to diffuse the circularly polarized light component reflected or transmitted by the cholesteric layer. The cholesteric layer may be a color filter having a red, a green and a blue pixel region for each of pixels. Each of the pixel regions reflects or transmits either of a right-handed circularly polarized light component and a left-handed circularly polarized light component in a selected wavelength band of an incident light.
    Type: Application
    Filed: May 29, 2002
    Publication date: December 5, 2002
    Applicant: Dai Nippon Printing Co., Ltd.
    Inventor: Keiji Kashima
  • Publication number: 20020180912
    Abstract: A method for making broadband cholesteric liquid crystals with improved bandwidth. The method includes the main steps of: (a) preparing a polymerization mixture containing first and second chiral liquid crystals, wherein the first chiral liquid crystal possesses a cholesteric liquid crystal phase and the second chiral liquid crystal possesses a helix-inversion characteristic, and at least one of the first or second chiral liquid crystals contains a polymerizable functional group; and (b) subjecting the polymerization mixture to a polymerization reaction, wherein the polymerization reaction is conducted such that the first chiral liquid crystal will go through a helix-inversion phenomenon. In a preferred embodiment, the second chiral liquid crystal has a temperature-dependent helicity which exhibits a helix inversion characteristic at a helix inversion temperature.
    Type: Application
    Filed: May 30, 2001
    Publication date: December 5, 2002
    Inventors: Pao-Ju Hsieh, Hui-Lung Kuo
  • Publication number: 20020180914
    Abstract: Disclosed are various reverse-mode direct-view liquid crystal displays (LCD) employing a liquid crystal having a characteristic wavelength in the non-visible spectrum, including transmissive mode displays, and methods of fabrication. In accordance with the principles disclosed, a transmitance mode direct-view LCD includes a first linear polarizer, a second linear polarizer, an internal light source and a cholesteric liquid crystal (CLC) located between the first and second linear polarizers and having a characteristic wavelength to reflect in a non-visible region of light. Portions of the CLC can selectively exhibit a planar state or a focal-conic state, the portions of the CLC in the planar state appearing black, and the portions of the CLC in the focal-conic state appearing white to an observer of the LCD.
    Type: Application
    Filed: December 19, 2001
    Publication date: December 5, 2002
    Applicant: Display Research Incorporated
    Inventors: Bao-Gang Wu, Jianan Hou, Jianmi Gao, Yong-Jing Wang, Shushan Li, hai Sun, Gang Chen
  • Publication number: 20020180913
    Abstract: Disclosed are various reverse-mode direct-view liquid crystal displays (LCD) employing a liquid crystal having a characteristic wavelength in the non-visible spectrum, including reflective and transflective mode displays, and methods of fabrication. In accordance with the principles disclosed, a reflectance mode direct-view LCD includes a polarizer, a reflector, and a cholesteric liquid crystal (CLC) packed between the polarizer and reflector and having a characteristic wavelength to reflect non-visible spectrum. Portions of the CLC can selectively exhibit a planar state or a focal-conic state, the portions of the CLC in the planar state appearing black, and the portions of the CLC in the focal-conic state appearing white to an observer of the LCD. A transflective mode LCD is derived by further combination of polarizers, transflective mirrors and internal light sources.
    Type: Application
    Filed: December 19, 2001
    Publication date: December 5, 2002
    Inventors: Bao-Gang Wu, Jianan Hou, Jianmi Gao, Yong-Jing Wang, Shushan Li, Ruihai Sun, Gang Chen
  • Publication number: 20020176041
    Abstract: A liquid crystal display apparatus includes a first liquid crystal layer having first liquid crystal exhibiting a cholesteric phase at a room temperature, and being tuned to selectively reflect light of a wavelength &lgr;1 within a visible wavelength range; and a second liquid crystal layer disposed on the first liquid crystal layer, having second liquid crystal exhibiting a cholesteric phase at the room temperature, and being tuned to selectively reflect light of a wavelength &lgr;2 within the visible wavelength range, wherein a difference between the selective reflection wavelengths &lgr;1 and &lgr;2 is in a range from 100 nm to 150 nm.
    Type: Application
    Filed: March 25, 2002
    Publication date: November 28, 2002
    Applicant: MINOLTA CO., LTD.
    Inventors: Akihito Hisamitsu, Noboru Ueda, Nobuyuki Kobayashi, Hideaki Ueda
  • Patent number: 6483563
    Abstract: The present invention is directed to a cholesteric liquid crystal display that includes a homogeneous alignment surface effective to provide increased brightness, low focal conic reflectance and/or reflected light that is to a significant degree circularly polarized. The homogeneous alignment surface substantially homogeneously aligns the liquid crystal director adjacent thereto. The homogeneous alignment surface may be disposed on one or both sides of a cell of the display. In the case of a cell in which the homogeneous alignment surface is disposed on only one side, the substrate with the inhomogeneous alignment surface may be upstream or downstream of the substrate with the homogeneous alignment surface relative to a direction of incident light. Also included especially in the case of a cell that has the homogeneous alignment surface on both sides is the use of a polarizer to provide very good brightness and low focal conic reflectance.
    Type: Grant
    Filed: October 9, 2001
    Date of Patent: November 19, 2002
    Assignee: Kent Displays, Inc.
    Inventors: Asad A. Khan, Xiao-Yang Huang, J. William Doane, Gene A. Miceli, Donald J. Davis
  • Patent number: 6459847
    Abstract: The invention relates to a method of manufacturing a patterned layer of a polymer material having a cholesteric order, in which the material is oriented in such a way that the axis of the molecular helix of the cholesterically ordered material extends transversely to the layer, and in which the layer is patterned in that it comprises at least one region in which the pitch of the molecular helix differs from that of another region. This inventive method comprises the following steps: a. providing a layer of a cholesterically ordered material comprising a quantity of a convertible compound which in its non-converted and in its converted state determines the pitch of the cholesterically ordered material to a different extent, in which the conversion of said compound may be induced by radiation, b. irradiating the layer in accordance with a desired pattern so that at least a part of the convertible compound in the irradiated parts of the layer is converted, c.
    Type: Grant
    Filed: August 7, 2000
    Date of Patent: October 1, 2002
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Peter Van De Witte, Johan Lub
  • Publication number: 20020135719
    Abstract: A reflective liquid crystal display device includes first and second substrates facing and spaced apart from each other; a first transparent electrode beneath the first substrate; a light absorption layer on the second substrate; a cholesteric liquid crystal (CLC) color filter layer on the light absorption layer, the CLC color filter layer being multi-layered and each layer of the CLC color filter including sub-color filters for red, green and blue colors arranged in an alternating order; a second transparent electrode on the CLC color filter layer; and a liquid crystal layer interposed between the first and second transparent electrodes. The CLC color filter layer may be single-layered and each sub-color filter may include a plurality of regions having a different central wavelength of reflection. The CLC color filter layer may be multi-layered with each sub-color filter including a plurality of regions having a different central wavelength of reflection.
    Type: Application
    Filed: February 14, 2002
    Publication date: September 26, 2002
    Inventors: Jong-Weon Moon, Sunghoe Yoon
  • Patent number: 6433853
    Abstract: A cholesteric liquid crystal layer has a helical pitch changing in the thickness direction and shows circular dichroism over a wavelength region having a width of at least 50 nm and including a wavelength of 520 nm, wherein the linearly polarized light obtained through a quarter-wavelength plate has a maximum degree of polarization at a wavelength not longer than 520 nm, or the degree of polarization thereof in a wavelength region on the shorter-wavelength side of 520 nm is higher than that in a wavelength region on the longer-wavelength side of 520 nm. The optical element comprises a multilayer structure composed of the cholesteric liquid crystal layer and at least one optical layer superposed thereon which is a retardation compensating plate, a polarizing plate, a light conductive plate, or a quarter-wavelength plate having an Nz of −0.8 to −2.0 and disposed on the longer-helical pitch side of the liquid crystal layer.
    Type: Grant
    Filed: February 2, 1999
    Date of Patent: August 13, 2002
    Assignee: Nitto Denko Corporation
    Inventors: Tadayuki Kameyama, Hironori Motomura, Naoki Takahashi
  • Patent number: 6421107
    Abstract: The invention relates to a process of preparing a multilayer cholesteric film comprising two or more layers of polymerized cholesteric liquid crystal (CLC) material with planar orientation, with the cholesteric helix axis oriented substantially perpendicular to the plane of the layer, wherein that the cholesteric helical pitch of adjacent layers is varied by controlled migration of a non-polymerized chiral material between the layers, to a multilayer cholesteric film obtainable by such a process, and to the use of the process and a multilayer cholesteric film thereby prepared in optical elements such as polarizers, compensators, alignment layers, color filters or holographic elements, in cosmetics and liquid crystal pigments, for decorative and security applications.
    Type: Grant
    Filed: July 3, 2000
    Date of Patent: July 16, 2002
    Assignee: Merck Patent Gesellaschaft
    Inventors: Simon Greenfield, Alison Linda May
  • Patent number: 6417903
    Abstract: An STN liquid crystal element, formed to sandwich a nematic liquid crystal 6 twist-aligned at an angle ranging from 180 degrees to 270 degrees between a first substrate 1 having a first electrode and a second substrate 2 having a second electrode, is disclosed A polarizing film is disposed outside the second substrate of the STN liquid crystal element through a retardation film or a twisted retardation film, a cholesteric liquid crystal polymer sheet is disposed outside the first substrate through a retardation film for circularly polarized light, and a light absorbing film is disposed outside the cholesteric liquid crystal polymer sheet, to thereby form a liquid crystal display device which enables metallic color display.
    Type: Grant
    Filed: July 3, 2000
    Date of Patent: July 9, 2002
    Assignee: Citizen Watch Co., Ltd.
    Inventor: Yasushi Kaneko
  • Patent number: 6417902
    Abstract: The invention relates to a process of preparing a multilayer cholesteric film comprising two or more layers of polymerized cholesteric liquid crystal (CLC) material with planar orientation, with the cholesteric helix axis oriented substantially perpendicular to the plane of the layer, wherein during preparation of the single layers the migration of unpolymerized material between adjacent layers is minimized, to a multilayer cholesteric film obtainable by such a process, and to the use of the process and a multilayer cholesteric film thereby prepared in optical elements such as polarizers, compensators, alignment layers, color filters or holographic elements, in cosmetics and liquid crystal pigments, for decorative and security applications.
    Type: Grant
    Filed: July 3, 2000
    Date of Patent: July 9, 2002
    Assignee: Merck Patent Gesellschaft
    Inventors: Simon Greenfield, Alison Linda May
  • Patent number: 6369868
    Abstract: A light controlling film is described comprising a polymerized polymer network of a crosslinked high molecular weight polymeric material and a low molecular weight cholesteric liquid crystal (CLC) material, wherein the high molecular weight and the low molecular weight form a material having cholesteric liquid crystal (CLC) order such that the film is a reflective circular polarizer whose bandwidth is controllable by an electric field impressed in the film.
    Type: Grant
    Filed: June 5, 1998
    Date of Patent: April 9, 2002
    Assignee: Reveo, Inc.
    Inventors: Bunsen Fan, Jian-feng Li, Le Li, Sadeg Faris
  • Publication number: 20020036735
    Abstract: A flat plate collimator and backlight system capable of improving the display characteristics of liquid crystal display devices are obtained. In order to achieve this end, a collimator is provided which comprises a cholesteric liquid crystal layer exhibiting a selective-reflection wavelength band with respect to perpendicularly-incident light in the wavelength range &lgr;1 to &lgr;2 (&lgr;1<&lgr;2), and which satisfies the relation &lgr;0<&lgr;1 with respect to the maximum-emission wavelength &lgr;0 in the emission spectrum of the light source with which the collimator is used in combination, and a backlight system employing this collimator and light source is provided.
    Type: Application
    Filed: September 24, 2001
    Publication date: March 28, 2002
    Applicant: FUFI PHOTO FILM CO., LTD.
    Inventors: Kohei Arakawa, Fumihiko Mochizuki, Kenichi Nakagawa, Mitsuyoshi Ichihashi
  • Patent number: 6359670
    Abstract: A transflective liquid-crystal display device comprising a display cell (1) and a reflective polarizer (9), which preferably incorporates a cholesteric mirror (12) which practically completely reflects incident radiation (light) (14) of a specific polarization (left-hand or right-hand) originating from the display cell (reflective effect) and which passes a substantial degree of radiation (15) of the same polarization originating from (a light source (10) on) the other side (transmissive effect).
    Type: Grant
    Filed: May 28, 1998
    Date of Patent: March 19, 2002
    Assignee: U.S. Philips Corporation
    Inventors: Dirk J. Broer, Hugo J. Cornelissen
  • Patent number: 6359673
    Abstract: A light modulating, electrically responsive sheet including a transparent substrate, and a transparent, electrically conductive layer formed over the transparent substrate. The sheet further includes a light modulating layer including a plurality of electrically responsive light modulating materials dispersed in the light modulating layer and having a plurality of optical states.
    Type: Grant
    Filed: June 21, 1999
    Date of Patent: March 19, 2002
    Assignee: Eastman Kodak Company
    Inventor: Stanley W. Stephenson
  • Publication number: 20020021392
    Abstract: A liquid crystal display element comprises a polarization plates, phase difference plates, a liquid crystal layer, and selectively reflective layers for reflecting part or whole of circularly polarized light in a specific direction. The products of the respective thicknesses of the polarization plate, phase difference plate, liquid crystal layer, and selectively reflective layer and the difference between an average refractive index in a direction perpendicular to each display plane and an average refractive index in a direction parallel to the display plane are set so that the absolute value of their sum total is 50 nm or less. Each selectively reflective layer is formed of a layer having positive refractive index anisotropy and a layer having negative refractive index anisotropy.
    Type: Application
    Filed: April 24, 2001
    Publication date: February 21, 2002
    Inventors: Toshiya Ohtake, Yuzo Hisatake, Atsuko Oono
  • Patent number: 6338807
    Abstract: In color printing, and in the fine arts, cholesteric liquid crystal (CLC) color inks are known to possess much higher color saturation and brightness than conventional pigment and dyed based inks. However, prior art CLC ink formulations are inconvenient because in the liquid phase they have to be confined in cells, and in the solid phase, they have to be applied at high temperature, and have to be aligned by some means to produce the optimum color. This invention solves the problem encountered in the CLC prior art, by making pre-aligned CLC platelets or flakes of appropriate thickness and size and mixing them in appropriate host fluids producing a novel CLC ink which can be applied at room temperature and without the need for alignment. The new pre-aligned room temperature CLC ink can be used as a substitute for conventional inks in almost all printing and plotting, and manual drawing and painting. Using the notch filter CLC platelets, the brightness is further enhanced.
    Type: Grant
    Filed: January 24, 1997
    Date of Patent: January 15, 2002
    Assignee: Reveo, Inc.
    Inventor: Sadeg M. Faris
  • Publication number: 20010055083
    Abstract: A reflective liquid crystal display (LCD) including a cholesteric liquid crystal polarizing device and a liquid crystal cell superimposed with one another. In various embodiments, the reflective LCD may be a normally white mode or normally black mode device. In another variation, the liquid crystal cell may include a 90° twisted nematic liquid crystal.
    Type: Application
    Filed: June 15, 2001
    Publication date: December 27, 2001
    Inventors: Yingqin Jiang, Aharon Hochbaum
  • Publication number: 20010055208
    Abstract: An optical element comprises a fluorescence luminous element that emits fluorescent light when excited and a cholesteric filter disposed at the incident side of the fluorescence luminous element at which excitation light enters the fluorescence luminous element. The cholesteric filter comprises a cholesteric layer operative to transmit the excitation light and to reflect backward scattered fluorescent light traveling thereto so as to be integrated with fluorescent light directly coming out of the cholesteric filter.
    Type: Application
    Filed: June 15, 2001
    Publication date: December 27, 2001
    Inventor: Koichi Kimura
  • Publication number: 20010050739
    Abstract: An array substrate for a reflective liquid crystal display can include a substrate, thin film elements formed on the substrate, and color filters formed on the thin film elements. Each of the color filters preferably include a cholesteric liquid crystal. A pixel electrode can be formed on each of the color filters so that the pixel electrode corresponds to a respective color filter.
    Type: Application
    Filed: May 30, 2001
    Publication date: December 13, 2001
    Applicant: LG. PHILIPS LCD CO., LTD
    Inventor: Jin Hee Jung
  • Publication number: 20010046015
    Abstract: The invention relates to a method of providing a decorative coating or text or the like on articles, like shavers, GSM's, cards, etc. The coating comprises a region-wise optically modified (patterned) cholesteric liquid crystalline layer, which is transferred onto a surface of the article by means of a transfer operation. The so-called in-mold decoration technique has been found to be very advantageous for the transfer of decorative (patterned) cholesteric liquid crystalline layers. In this technique the layer is (releasably) deposited on a plastic carrier foil and provided with a layer of adhesive. The assembly is inserted in an injection mold before the injection molding of polymer material starts. In this way decorative coatings (e.g. multi color images) and texts or the like can be even applied onto, non-even and slightly curved substrates.
    Type: Application
    Filed: April 16, 2001
    Publication date: November 29, 2001
    Applicant: Koninklijke Philips Electronics N.V.
    Inventors: Peter Van De Witte, Johan Lub
  • Patent number: 6320632
    Abstract: A color reflection type polarizer of a high quality and easy to manufacture is disclosed. The color reflection type polarizer is fabricated by disposing an optically anisotropic medium between a reflector and a polarizer, the optically anisotropic medium having a retardation in a plane thereof.
    Type: Grant
    Filed: June 30, 1999
    Date of Patent: November 20, 2001
    Assignee: Nippon Mitsubishi Oil Corporation
    Inventor: Suzushi Nishimura
  • Publication number: 20010035928
    Abstract: The liquid crystal device of the present invention effectively prevents reversion of bright/dark states between a reflective display mode and a transmissive display mode. The liquid crystal device includes a first absorptive polarizer, which receives light from outside;a liquid crystal cell, which receives light emitted from the first absorptive polarizer; a second absorptive polarizer, which receives light emitted from the liquid crystal cell; and a reflective polarizer, which receives light emitted from the second absorptive polarizer. The reflective polarizer has an axis of reflection in a predetermined direction to reflect at least part of light that has been transmitted through the first absorptive polarizer, the liquid crystal cell, and the second absorptive polarizer to be incident on the reflective polarizer.
    Type: Application
    Filed: June 29, 2001
    Publication date: November 1, 2001
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Masahiro Kuroiwa, Miwa Naonori, Atsunari Tsuda
  • Patent number: 6307604
    Abstract: Light source having a luminescent layer (3,8) whose light is guided through an optical filter (5,9) comprising at least one cholesteric crystal layer (cholesteric filter).
    Type: Grant
    Filed: February 2, 1995
    Date of Patent: October 23, 2001
    Assignee: U.S. Philips Corporation
    Inventors: Rifat Hikmet, Ralf Raue, Thomas Welker
  • Patent number: 6300989
    Abstract: A polarizer 130, and a reflecting plate 195 are provided on the lower side of a TN liquid crystal 140, and a light-scattering layer 150 and a polarized light separator 160 are provided on the upper side of the TN liquid crystal in this order. The polarized light separator 160 reflects light which is in the direction of the reflection axis and in a certain wavelength region (&Dgr;&lgr;), and transmits light which is in the direction of the reflection axis and in an other wavelength region (−&Dgr;&lgr;). On a voltage non-application section 120, light in the direction parallel to a transmission axis 161 of the polarized light separator 160 is transmitted and is reflected by a reflecting plate 195, so that the display becomes bright.
    Type: Grant
    Filed: February 11, 1999
    Date of Patent: October 9, 2001
    Assignee: Seiko Epson Corporation
    Inventor: Chiyoaki Iijima