Patents Examined by Tiep H. Nguyen
  • Patent number: 5774197
    Abstract: The present invention is directed to the prevention of reversal and deterioration of a screen at right and left viewing angles and upper and lower viewing angles in an OCB-mode liquid-crystal display.It is possible to prevent deterioration of a screen by obtaining the optimum value of ?absolute value {R(V.sub.1)} of retardation before correction by phase compensation film!/wavelength (.lambda.) at a lower-side driving voltage for each color of R, G, and B and thereby, preventing an optical rotation of liquid crystal on B wavelength. Specifically, B wavelength is set to R(V.sub.1)/.lambda..ltoreq.0.85. By adjusting a cell gap of each color, display characteristics of a screen at right and left viewing angles are improved.
    Type: Grant
    Filed: December 10, 1996
    Date of Patent: June 30, 1998
    Assignee: International Business Machines Corporation
    Inventor: Hajime Nakamura
  • Patent number: 5771082
    Abstract: A device for attenuating stray capacitances in a liquid crystal and active matrix screen. The screen includes a substrate plate on one face of which there are deposited electrodes and thin film components controlling the electrodes. It also includes a back plate having one or more back-plate electrodes and covering the face of the substrate plate. A liquid crystal is contained between the electrode of the substrate plate and the back-plate electrodes. A ground plane forms an equipotential over the whole surface of the screen between the substrate plate and the thin films of the control components. The ground plane along with a film of insulating material forms a storage capacitance.
    Type: Grant
    Filed: December 12, 1996
    Date of Patent: June 23, 1998
    Assignee: Thomson-LCD
    Inventors: Rene Chaudet, Jean-Michel Vignolle
  • Patent number: 5771083
    Abstract: A liquid crystal display device incorporating an active matrix substrate having an inter-layer insulating film between a pixel electrode and gate and source signal lines. In this liquid crystal display device, the source signal line has a double-layer structure of an upper-layer line and a lower-layer line, but the upper-layer line is eliminated at the intersection of the gate signal line and the source signal line. This structure prevents a decrease in the thickness of the inter-layer insulating layer on the intersection of the gate signal line and the source signal line.
    Type: Grant
    Filed: October 1, 1996
    Date of Patent: June 23, 1998
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Masaki Fujihara, Yuzuru Kanemori, Masaya Okamoto
  • Patent number: 5767926
    Abstract: A liquid crystal display having an improved display characteristic and having a ring-structured storage capacitor of an independent wiring type wherein disconnection and/or short circuit defects are reduced and a method for manufacturing the same. The liquid crystal display has one or a plurality of first electrodes within each pixel region, for forming one or a plurality of auxiliary capacitors in conjunction with the opposing pixel electrode. The first electrodes surround the pixel electrodes in a ring type structure, and are connected to each other between adjacent pixel portions by at least one wiring connecting portion. The first electrodes are driven independently from the scanning signal lines and the display signal lines. Forming the first electrodes of the capacitors as independent wiring type having a ring structure simplifies the manufacturing process and utilizes the maximum pixel area.
    Type: Grant
    Filed: February 13, 1996
    Date of Patent: June 16, 1998
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Sang-soo Kim, Dong-gyu Kim, Yong-gug Bae, Jong-in Choung, Jun-ho Song
  • Patent number: 5760862
    Abstract: Display device which will be considerably flatter by contacting conductor tracks on one side of a substrate via connectors with conductor parts contacting the conductor tracks around the edge of the substrate with contact faces on the other side of the substrate. These contact faces extend parallel to the substrate and may directly or indirectly contact conductor tracks on, for example a printed circuit board.
    Type: Grant
    Filed: June 27, 1996
    Date of Patent: June 2, 1998
    Assignee: U.S. Philips Corporation
    Inventor: Marcel S. B. Bachus
  • Patent number: 5757453
    Abstract: A liquid crystal display (LCD) device includes: a plurality of gate lines and a plurality of data lines arranged in the form of a matrix; a plurality of transistors each having a gate, a source and a drain, and each disposed at an intersecting point of the lines; a plurality of pixel electrodes connected to the drain electrodes of the respective transistors; and a plurality of capacitors formed on the pixel electrodes. The capacitor includes a capacitor electrode, a gate insulating layer, a semiconductor layer and a protective insulating layer. The semiconductor layer of the capacitor is composed of the same material as that of a semiconductor region of the transistor. An etch stop layer is used for protecting a gate insulating layer during etching a protective insulating layer situated above the gate insulating layer. For the etch stop layer, an amorphous silicon layer or a metal layer are used.
    Type: Grant
    Filed: August 25, 1995
    Date of Patent: May 26, 1998
    Assignee: LG Electronics, Inc.
    Inventors: Woo Sup Shin, In Duk Song
  • Patent number: 5754262
    Abstract: A daylight readable LCD which may be used to communicate information as high contrast images (static or dynamic, color or monochrome) in bright ambient lighting conditions over a wide temperature range in direct sunlight. A contrast enhancement filter assembly is disposed at the interface between a backlit display and a user. The contrast enhancement filter assembly includes a triple bandpass contrast enhancement filter that preferably passes light efficiently in each of the red, green, and blue primary wavelengths and substantially absorbs all other wavelengths. Display contrast is increased because of the absorption of incident light having wavelengths that differ from the light produced by the internal backlight source within the display. This results in the display having a blacker background and enhanced purity of the color primaries. The display element is disposed generally behind the contrast enhancement filter assembly.
    Type: Grant
    Filed: July 28, 1997
    Date of Patent: May 19, 1998
    Assignee: Litton Systems, Inc.
    Inventor: J. Michael Lengyel
  • Patent number: 5754268
    Abstract: A display device in which an area corresponding to electrodes placed one upon another is arranged to change into a light-transmissive state by applying a potential difference between the electrodes includes a pair of transparent electrodes respectively formed on a pair of transparent substrates, one of the pair of transparent electrodes having at least an electrode area of the same shape as a display pattern, a display substance disposed between the pair of transparent substrates, and a third transparent substrate disposed between the pair of transparent substrates, the third transparent substrate having a transparent electrode formed in an area other than an area corresponding to the display pattern.
    Type: Grant
    Filed: January 21, 1997
    Date of Patent: May 19, 1998
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yoshihiko Aihara, Akira Ishizaki, Terutake Kadohara
  • Patent number: 5748277
    Abstract: A flat-panel liquid crystal display. The display includes a flat sheet of bistable chiral nematic liquid crystal material activated by a drive circuit that individually controls the display state of multiple picture elements at a refresh rate 1000 scan lines per second. The driver circuitry activates the liquid crystal domains into homeotropic states over a relatively long activation period and then, during a short (.about.1 msec.) selection period, either keeps the domains in a homeotropic state or initiate a transition to the transient twisted planar state. The drivers then activate the domains in an evolution phase to provide either focal conic or twisted planar end states across the two-dimensional array of picture elements.
    Type: Grant
    Filed: February 17, 1995
    Date of Patent: May 5, 1998
    Assignee: Kent State University
    Inventors: Xiao-Yang Huang, Philip J. Bos, Deng-Ke Yang
  • Patent number: 5748272
    Abstract: A polymer dispersed liquid crystal optical device is presented which has optical elements which control reflection, transmission and diffraction of incident light entering the device by adjusting the magnitude of the electrical field applied to the device between a maximum and a minimum limits. An optical element consists of a polymer material having an electrical field-independent refractive index, and a liquid crystal material having an electrical field-dependent refractive index. The optical elements are distributed through the device at specific inter-element spacings, thus enabling to generate reflection of incident light in accordance with Bragg's law of reflection. The inter-element spacings can also be varied by the application of the field, thus enabling to generate reflection of light of a desired wavelength. Such optical elements are ideal for use in full color optical display apparatus of a matrix driven type.
    Type: Grant
    Filed: June 10, 1996
    Date of Patent: May 5, 1998
    Assignee: Nippon Telegraph and Telephone Corporation
    Inventors: Keiji Tanaka, Kinya Kato, Shinji Tsuru, Shigenobu Sakai
  • Patent number: 5745199
    Abstract: A transmission type liquid crystal display device having a liquid crystal cell and a microlens array sheet attached to the observation surface of the liquid crystal cell, wherein the microlens array sheet has at least one diffusion axis in the plane and the direction of the diffusion axis is conformed to a direction of the liquid crystal orientation of the liquid crystal cell, and a transmission type liquid crystal display device including a liquid crystal cell, a microlens array sheet attached to the observation surface of the liquid crystal cell and a backlight source, wherein a specified relationship is provided between the directivity of light emission of the backlight source and the pitch of arrangement of display elements of the liquid crystal cell in a minute unit lens arrangement direction. This liquid crystal display device is substantially independent of view angle and has a wide visible angle and high image quality.
    Type: Grant
    Filed: September 25, 1996
    Date of Patent: April 28, 1998
    Assignee: Toray Industries, Inc.
    Inventors: Motoyuki Suzuki, Tetsuo Uchida, Yuko Mikami
  • Patent number: 5745195
    Abstract: An active matrix liquid crystal display having auxiliary capacitors. Two transparent conductive layers of ITO are formed on opposite sides of an insulating film. The first conductive layer forms pixel electrodes. The second transparent conductive film overlaps at least parts of the pixel electrodes via the insulating film to form the auxiliary capacitors without deteriorating the aperture ratio of the pixels.
    Type: Grant
    Filed: May 7, 1996
    Date of Patent: April 28, 1998
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventor: Hongyong Zhang
  • Patent number: 5745206
    Abstract: The liquid crystal display panel comprising a twisted nematic liquid crystal inserted between a pair of substrates having alignment films, respectively. The liquid crystal twists from one substrate to the other substrate at a predetermined twist angle which is greater than zero degrees but smaller than 90 degrees. A polarizer and an analyzer are arranged crosswise. The alignment films are divided into minute regions so that the liquid crystal molecules in one of the regions align in one direction and the liquid crystal molecules in the other region align in another direction. The product (.DELTA.nd) of the anisotropy of the refractive index (.DELTA.n) and the layer thickness (d) of the liquid crystal is smaller than approximately 0.5 .mu.m and ensures a linearly polarized light incident onto the liquid crystal rotates approximately 90 degrees before the light emerges from the liquid crystal.
    Type: Grant
    Filed: April 11, 1997
    Date of Patent: April 28, 1998
    Assignee: Fujitsu Limited
    Inventors: Yoshio Koike, Syun Tsuyuki, Katsufumi Ohmuro, Tsuyoshi Kamada
  • Patent number: 5745200
    Abstract: A birefringence control type color liquid crystal display device includes a liquid crystal cell having first and second substrates; first and second electrodes formed on opposing surfaces of the first and second substrates; a first aligning film formed on the first electrode and subjected to an aligning treatment in a first direction; a second aligning film formed on the second electrode and the second substrate and subjected to an aligning treatment in a second direction intersecting the first direction at 90 degrees; and a liquid crystal sealed between the first and second aligning films and twisted at 90 degrees.
    Type: Grant
    Filed: April 24, 1995
    Date of Patent: April 28, 1998
    Assignee: Casio Computer Co., Ltd.
    Inventors: Zenta Kikuchi, Tetsushi Yoshida, Hisashi Aoki
  • Patent number: 5745201
    Abstract: An object of the invention is to facilitate identifying the display color of each pixel during a test process and to apply a correction to a defective switching device in accordance with a test criterion established for each display color. On one transparent substrate, there are formed gate wiring and source wirings intersecting at right angles to each other so that insulation therebetween is maintained, and a pixel electrode and a TFT device are formed for each pixel, thus constructing one substrate member. On another transparent substrate, there is formed a counter electrode facing the pixel electrodes, and identifying means for identifying the display color of each pixel is formed on the side opposite from the side where the counter electrode is formed, the identifying means then being covered with a light-blocking member, thus constructing the another substrate member. The light-blocking member contains openings formed therethrough in portions facing the pixel electrodes.
    Type: Grant
    Filed: October 2, 1996
    Date of Patent: April 28, 1998
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Katsuhiro Kawai, Satoshi Yabuta, Masaya Okamoto, Masaru Kajitani
  • Patent number: 5739880
    Abstract: In a liquid crystal display in which the region around a display region is reduced, a black matrix BM is made of a colored organic resin. Substantially all over the periphery of a seal member SL, there are formed portions in which the seal member SL and the black matrix BM are and are not overlapped. A shielding tape TAPE is stuck to that portion of the lower face of a lower transparent glass substrate SUB1, which corresponds to the non-overlapped portion, to prevent the leakage of light from the seal portion.
    Type: Grant
    Filed: November 29, 1996
    Date of Patent: April 14, 1998
    Assignee: Hitachi, Ltd.
    Inventors: Masahiko Suzuki, Tsutomu Isono, Kimitoshi Ohgiichi, Akira Ishii, Jun-ichi Ohwada
  • Patent number: 5737049
    Abstract: A liquid crystal display (LCD) device includes: a plurality of gate lines and a plurality of data lines arranged in the form of a matrix; a plurality of transistors each having a gate, a source and a drain, and each disposed at an intersecting point of the lines; a plurality of pixel electrodes connected to the drain electrodes of the respective transistors; and a plurality of capacitors formed on the pixel electrodes. The capacitor includes a capacitor electrode, a gate insulating layer, a semiconductor layer and a protective insulating layer. The semiconductor layer of the capacitor is composed of the same material as that of a semiconductor region of the transistor. An etch stop layer is used for protecting a gate insulating layer during etching a protective insulating layer situated above the gate insulating layer. For the etch stop layer, an amorphous silicon layer or a metal layer are used.
    Type: Grant
    Filed: August 25, 1995
    Date of Patent: April 7, 1998
    Assignee: LG Electronics, Inc.
    Inventors: Woo Sup Shin, In Duk Song
  • Patent number: 5737046
    Abstract: It is an object of the invention to display white and black colors simultaneously in addition to a color display, in a birefringence control type liquid crystal display device using a high polymer film in optical compensation plate. In the birefringence control type liquid crystal display device using a high polymer film in the optical compensation plate, the product d.DELTA.n of a cell gap d and a refractive index anisotropy .DELTA.n of the liquid crystal cell is set in a range of 1700 nm to 1950 nm, the difference (d.DELTA.n-d.sub.R n.sub.R) of the d.DELTA.n of the liquid crystal cell and the product d.sub.R .DELTA.n.sub.R of a refractive index anisotropy .DELTA.n.sub.R and a film thickness d.sub.R of the phase difference plate is set in a range of 750 nm to 850 nm, the crossing angle of the orientation direction of the upper side of the liquid crystal layer and the slow axis of the phase difference plate is set in a range of 80.degree. to 100.degree.
    Type: Grant
    Filed: August 12, 1996
    Date of Patent: April 7, 1998
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Hiroyuki Moriwaki, Manabu Abiru, Koji Yabuta, Nobuhiro Kasai
  • Patent number: 5731853
    Abstract: The liquid crystal display device according to this invention realizes three-dimensional picture images without using lenticular lenses etc. In addition, this liquid crystal display device has a transparent picture screen so that remote display picture images or three-dimensional picture images of high luminance are seen multiplexed with the background. The display device is constructed by arranging picture elements in which volume-phase type holograms are formed by a periodical construction of liquid crystals and polymers. Diffraction light from first picture element groups which are distributed uniformly reaches a left eye of an observer while diffraction light from second picture element groups which are distributed uniformly reaches a right eye of an observer. The condition of the picture elements are switched to diffract irradiated light or to transmit the light, thus a desired picture image comprising a dot matrix can be displayed.
    Type: Grant
    Filed: February 16, 1996
    Date of Patent: March 24, 1998
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Yoshinao Taketomi, Shiro Asakawa, Eiichiro Okuda
  • Patent number: 5729308
    Abstract: In an active matrix display device, a circuit including at least five thin film transistors (TFTs) which are provided with an approximately M-shaped semiconductor region for a single pixel electrode and gate lines and a capacitances line which cross the M-shaped semiconductor region, is used as a switching element. Each of the TFT have offset regions and lightly doped drain (LDD) regions. Then, by supplying a selection signal to the gate lines, the TFTs are operated, thereby writing data to the pixel, while a suitable voltage is supplied to the capacitance line, a channel is formed thereunder and it becomes a capacitor. Thus the amount of discharge from the pixel electrode is reduced by the capacitor.
    Type: Grant
    Filed: February 15, 1996
    Date of Patent: March 17, 1998
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Sunpei Yamazaki, Jun Koyama, Yasuhiko Takemura