Patents by Inventor Katsuhiko Kumagawa

Katsuhiko Kumagawa 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: 6906769
    Abstract: A liquid crystal screen display is disclosed which is capable of restraining occurrence of display unevenness. In the display of the invention, a conductive member to which a negative voltage is applied is placed between a substrate and an alignment layer so as to be in partial contact with the alignment layer. Uneven ion distribution attributable to ion generation within broken or pin hole parts of an overcoat film is restrained, for instance, by exposing gate signal lines etc. to the alignment layer so that ions are intentionally generated in the regions of the liquid crystal layer corresponding to the exposed regions.
    Type: Grant
    Filed: August 30, 2001
    Date of Patent: June 14, 2005
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Ichiro Sato, Katsuhiko Kumagawa, Kazuo Inoue, Kazuhiro Nishiyama
  • Patent number: 6900852
    Abstract: An active matrix liquid crystal display element capable of reducing flicker comprises: a plurality of source lines; a plurality of gate lines arranged so as to intersect the plurality of source lines in a plan view, for transmitting a gate signal; a plurality of pixels defined by the plurality of source lines and the plurality of gate lines, constituting an image display plane; a pixel electrode provided for every pixel; an opposed electrode facing the pixel electrode across a liquid crystal layer; a storage capacitor for holding a voltage applied between its corresponding pixel electrode and the opposed electrode; and a pixel transistor having a source electrode, a drain electrode and a gate electrode which are connected to a corresponding one of the source lines, a corresponding one of the pixel electrodes and a corresponding one of the gate lines respectively, and being turned ON or OFF by the gate signal, wherein an index B given by B=Lst/Lgd is equal to or greater than 7, where a periphery length of the
    Type: Grant
    Filed: January 30, 2002
    Date of Patent: May 31, 2005
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Takashi Okada, Yukio Tanaka, Masanori Kimura, Katsuhiko Kumagawa
  • Patent number: 6896940
    Abstract: A liquid crystal screen display is disclosed which is capable of restraining occurrence of display unevenness. In the display of the invention, a conductive member to which a negative voltage is applied is placed between a substrate and an alignment layer so as to be in partial contact with the alignment layer. Uneven ion distribution attributable to ion generation within broken or pin hole parts of an overcoat film is restrained, for instance, by exposing gate signal lines etc. to the alignment layer so that ions are intentionally generated in the regions of the liquid crystal layer corresponding to the exposed regions.
    Type: Grant
    Filed: March 30, 2004
    Date of Patent: May 24, 2005
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Ichiro Sato, Katsuhiko Kumagawa, Kazuo Inoue, Kazuhiro Nishiyama
  • Publication number: 20050099581
    Abstract: A liquid crystal display device comprises a pair of substrates (1, 2) each having an electrode (13, 5), a liquid crystal layer held between the pair of substrates (1, 2) in which at least two kinds of projections (20, 21) having different projection heights are formed on one of the pair of substrates (1, 2) using the same material. These projections (20, 21) are obtained by the process comprising the steps, i.e., a resin film formation step of forming a projection resin film on the surface of one of the pair of substrates (1, 2) using photosensitive resin, and a projection formation step of simultaneously forming at least two types of projections (20, 21) having different projection heights on the substrate (2) using a photomask having variable transmittances and conducting exposure and development in such a manner that resulting thickness of the projection resin film can be varied.
    Type: Application
    Filed: December 7, 2004
    Publication date: May 12, 2005
    Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.
    Inventors: Kazuo Inoue, Katsuhiko Kumagawa, Akio Takimoto
  • Publication number: 20050058027
    Abstract: Laser beams respectively emitted from a SHG blue laser unit and a red semiconductor laser unit that have photo detectors respectively are turned into parallel lights by a collimator lens and then coupled by a dielectric multi-layer film mirror so as to be propagated on the same optical axis. The dielectric multi-layer film mirror is configured so as to transmit light with a wavelength of 500 nm or shorter and reflect light with a wavelength of 500 nm or longer for both P wave and S wave. The lights that are transmitted and reflected by the dielectric multi-layer film mirror pass through a polarizing hologram and a phase variable wave plate and are focused on an optical disk by an objective lens. In this manner, a simple configuration can realize a compatibility with many types of optical disks and a stable signal detection even when using a polarizing optical detection system.
    Type: Application
    Filed: October 27, 2004
    Publication date: March 17, 2005
    Applicant: Matsushita Electric Industrial Co., Ltd.
    Inventors: Yasuo Kitaoka, Ken'ichi Kasazumi, Katsuhiko Kumagawa, Kazuhisa Yamamoto, Hidenori Wada
  • Publication number: 20050030880
    Abstract: Laser beams respectively emitted from a SHG blue laser unit and a red semiconductor laser unit that have photo detectors respectively are turned into parallel lights by a collimator lens and then coupled by a dielectric multi-layer film mirror so as to be propagated on the same optical axis. The dielectric multi-layer film mirror is configured so as to transmit light with a wavelength of 500 nm or shorter and reflect light with a wavelength of 500 nm or longer for both P wave and S wave. The lights that are transmitted and reflected by the dielectric multi-layer film mirror pass through a polarizing hologram and a phase variable wave plate and are focused on an optical disk by an objective lens. In this manner, a simple configuration can realize a compatibility with many types of optical disks and a stable signal detection even when using a polarizing optical detection system.
    Type: Application
    Filed: June 22, 2004
    Publication date: February 10, 2005
    Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.
    Inventors: Yasuo Kitaoka, Ken'ichi Kasazumi, Katsuhiko Kumagawa, Kazuhisa Yamamoto, Hidenori Wada
  • Patent number: 6850303
    Abstract: The liquid crystal display device having an array substrate (10) provided with a pixel electrode (3) disposed in a region defined by two adjacent gate wirings (1) and two adjacent source wirings (2), a switching element (5) for switching a voltage applied to the pixel electrode (3) from the source wiring (2) based on a signal volume fed from the gate wiring (1), a common wiring (8) formed between the two adjacent gate wirings (1), a common electrode (4) being electrically connected to the common wiring (8) and generating an electric field between the common electrode (4) and the pixel electrode (3) for driving the liquid crystal, and a storage capacity electrode (20a) electrically connected to the common wiring (8), wherein the common wiring (8) and the storage capacity electrode (20a) are layered so as to hold at least some part of the pixel electrode (3) in between through insulating layers (6a, 6b).
    Type: Grant
    Filed: September 27, 2001
    Date of Patent: February 1, 2005
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Masanori Kimura, Katsuhiko Kumagawa, Tetsuo Fukami, Hiroyuki Yamakita, Satoshi Asada
  • Patent number: 6850309
    Abstract: A liquid crystal display device comprises a pair of substrates (1, 2) each having an electrode (13, 5), a liquid crystal layer held between the pair of substrates (1, 2) in which at least two kinds of projections (20, 21) having different projection heights are formed on one of the pair of substrates (1, 2) using the same material. According to one embodiment of the present invention, the liquid crystal display device further comprises a first projection which maintains a constant space between the pair of substrates and a second projection which forms asperities on the electrode to diffuse the reflected light. These projections (20, 21) are obtained by the process comprising the steps, i.e.
    Type: Grant
    Filed: January 9, 2002
    Date of Patent: February 1, 2005
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Kazuo Inoue, Katsuhiko Kumagawa, Akio Takimoto
  • Patent number: 6819646
    Abstract: Laser beams respectively emitted from a SHG blue laser unit and a red semiconductor laser unit that have photo detectors respectively are turned into parallel lights by a collimator lens and then coupled by a dielectric multi-layer film mirror so as to be propagated on the same optical axis. The dielectric multi-layer film mirror is configured so as to transmit light with a wavelength of 500 nm or shorter and reflect light with a wavelength of 500 nm or longer for both P wave and S wave. The lights that are transmitted and reflected by the dielectric multi-layer film mirror pass through a polarizing hologram and a phase variable wave plate and are focused on an optical disk by an objective lens. In this manner, a simple configuration can realize a compatibility with many types of optical disks and a stable signal detection even when using a polarizing optical detection system.
    Type: Grant
    Filed: January 18, 2000
    Date of Patent: November 16, 2004
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Yasuo Kitaoka, Ken'ichi Kasazumi, Katsuhiko Kumagawa, Kazuhisa Yamamoto, Hidenori Wada
  • Patent number: 6816208
    Abstract: This is an active matrix liquid crystal display device comprising a capacitive accumulation portion formed by overlapping a pixel electrode, an insulating layer and a common electrode for each pixel area, and a non-electrode area in a part of the pixel area which is not covered with a pixel electrode, wherein a peripheral shape of said capacitive accumulation portion on a side contacting said non-electrode area is substantially the same between the respective pixels, and a value of a storage capacity in said capacitive accumulation portion differs on a feeding side and on a termination side, the value on the feeding side being larger than the value on the termination side. Thereby, a constant aperture ratio can be maintained by changing the storage capacity value for each pixel.
    Type: Grant
    Filed: July 23, 2001
    Date of Patent: November 9, 2004
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Tetsuo Fukami, Katsuhiko Kumagawa, Masanori Kimura
  • Publication number: 20040196415
    Abstract: A liquid crystal display element driving method or a liquid crystal display device uses a liquid crystal display element having a plurality of pixels constituting a screen; divides a frame period into a plurality of write periods and outputs gate signals to select the pixels sequentially during the write periods; forms each of source signals such that the source signal includes a picture signal and a non-picture signal respectively assigned for the write periods; writes each of the source signals corresponding to the selected pixels to each of the pixels with its polarity being alternated; and displays an image responsive to the source signals on the screen of the liquid crystal display element in such a manner that a transmittivity of liquid crystals of each of the pixels is controlled in accordance with the written source signal, wherein the non-picture signal having a polarity identical to that of the picture signal to be written subsequently is written to the pixels.
    Type: Application
    Filed: May 3, 2004
    Publication date: October 7, 2004
    Inventors: Masanori Kimura, Ichiro Sato, Katsuhiko Kumagawa
  • Patent number: 6801293
    Abstract: The curing, by UV-light irradiation, of a sealing resin after injecting liquid crystal is made reliable. The display characteristics and the like of an in-plane electric field mode liquid crystal element are improved. To resolve these problems, the viscosity of the sealing resin is lowered, while bubbles mixed in the sealing resin are eliminated by ultrasonic waves, for example. Also, a means for eliminating ions and charges in the liquid crystal layer is devised.
    Type: Grant
    Filed: April 5, 2002
    Date of Patent: October 5, 2004
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Kazuhiro Nishiyama, Junko Asayama, Kazunori Komori, Yukio Tanaka, Akio Takimoto, Kazuo Inoue, Katsuhiko Kumagawa, Ichiro Sato, Hirofumi Wakemoto, Noriyuki Kizu, Masanori Kimura, Keisuke Tsuda
  • Patent number: 6801264
    Abstract: One of a pair of substrates with liquid crystals sandwiched therebetween includes a plurality of pixels each of which is provided with a scanning electrode, an image signal electrode, a switching element provided at an intersection of the scanning electrode and the image signal electrode, a pixel electrode connected to the image signal electrode via the switching element, a counter electrode, and a busbar electrically connected to the counter electrode. A portion of the pixel electrode is overlapped with the busbar so as to make up a storage capacitance. A shape of the pixel electrode is altered for each pixel so that a value of the storage capacitance becomes smaller from a feeding side to a termination side. The portion of the pixel electrode overlapped with the busbar so as to make up the storage capacitance is located within the busbar in a plan view of the device.
    Type: Grant
    Filed: February 9, 2004
    Date of Patent: October 5, 2004
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Katsuhiko Kumagawa, Masanori Kimura, Tetsuo Fukami
  • Publication number: 20040179162
    Abstract: A liquid crystal screen display is disclosed which is capable of restraining occurrence of display unevenness. In the display of the invention, a conductive member to which a negative voltage is applied is placed between a substrate and an alignment layer so as to be in partial contact with the alignment layer. Uneven ion distribution attributable to ion generation within broken or pin hole parts of an overcoat film is restrained, for instance, by exposing gate signal lines etc. to the alignment layer so that ions are intentionally generated in the regions of the liquid crystal layer corresponding to the exposed regions.
    Type: Application
    Filed: March 30, 2004
    Publication date: September 16, 2004
    Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.
    Inventors: Ichiro Sato, Katsuhiko Kumagawa, Kazuo Inoue, Kazuhiro Nishiyama
  • Patent number: 6787829
    Abstract: A liquid crystal display panel of the invention is such that, in a pixel region defined by a region of the array substrate surrounded by a pair of image signal lines and a pair of scanning signal lines, of a line-shaped pixel electrode and a common electrode, the electrode that is disposed adjacent to and parallel to a signal line is made of an opaque conductor and at least one of the other electrodes is made of a transparent conductor. Adverse effects of the electric field formed between a signal line and an adjacent electrode thereto are suppressed and a sufficient aperture ratio is ensured by using a transparent conductor for the electrode contributing good display.
    Type: Grant
    Filed: December 5, 2001
    Date of Patent: September 7, 2004
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Tetsuo Fukami, Katsuhiko Kumagawa, Hiroyuki Yamakita, Masanori Kimura, Michiko Okafuji, Satoshi Asada
  • Patent number: 6781659
    Abstract: A liquid crystal display device, wherein liquid crystal is driven by an electric field that is parallel to a substrate, includes a plurality of gate lines (Xm−1), (Xm) and a plurality of data lines (Yn−1), (Yn) provided such that the data lines intersect with the plurality of gate lines, switching elements (13) connected to the gates lines (Xm−1) and the data lines (Yn−1), pixel electrodes (11) connected to the data lines (Yn−1) via the switching elements (13), and opposing electrodes (12) forming pairs with the pixel electrodes (11), wherein a plurality of storage capacities (14a), (14b) for maintaining a charge of the pixel electrodes (11) are provided in a distributed arrangement associated with points where the plurality of gate lines (Xm−1), (Xm) and the plurality of data lines (Yn−1), (Yn) intersect.
    Type: Grant
    Filed: October 12, 2001
    Date of Patent: August 24, 2004
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Akinori Shiota, Hiroyuki Yamakita, Katsuhiko Kumagawa, Sadayoshi Hotta, Yoneharu Takubo
  • Publication number: 20040160541
    Abstract: One of a pair of substrates with liquid crystals sandwiched therebetween includes a plurality of pixels each of which is provided with a scanning electrode, an image signal electrode, a switching element provided at an intersection of the scanning electrode and the image signal electrode, a pixel electrode connected to the image signal electrode via the switching element, a counter electrode, and a busbar electrically connected to the counter electrode. A portion of the pixel electrode is overlapped with the busbar so as to make up a storage capacitance. A shape of the pixel electrode is altered for each pixel so that a value of the storage capacitance becomes smaller from a feeding side to a termination side. The portion of the pixel electrode overlapped with the busbar so as to make up the storage capacitance is located within the busbar in a plan view of the device.
    Type: Application
    Filed: February 9, 2004
    Publication date: August 19, 2004
    Applicant: Matsushita Electric Industrial Co., Ltd.
    Inventors: Katsuhiko Kumagawa, Masanori Kimura, Tetsuo Fukami
  • Patent number: 6774963
    Abstract: A liquid crystal display device having a back side light source, which can perform displays of both a transmissive type and a reflective type, employs interference filters formed with a multilayer film 18, 19 and 20 as color filters to be used for color display. The back side light source is switched off in use as a reflective type display. The display in the liquid crystal display device can be inverted to a negative. The normal direction of the multilayer film of the interference filter may differ from the normal direction of a substrate.
    Type: Grant
    Filed: October 12, 2001
    Date of Patent: August 10, 2004
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Kenji Nakao, Katsuhiko Kumagawa, Tsuyoshi Uemura, Naohide Wakita
  • Patent number: 6762816
    Abstract: A liquid crystal display comprises an array substrate in which a common electrode, a pixel electrode, a scanning signal line, a video signal line and a semiconductor switching element are provided, an opposed substrate, and a liquid crystal layer interposed between the array substrate and opposed substrate. The line width of at least either the common electrode or the pixel electrode is larger than the distance between the common electrode and the pixel electrode. The film thickness of at least one of the common electrode and the pixel electrode is larger than the thickness of at least either the scanning signal line or the video signal line. As a result, an inplane electric field liquid crystal display having a wide viewing angle, high-speed response, and high image quality such as high luminance is provided.
    Type: Grant
    Filed: December 11, 2001
    Date of Patent: July 13, 2004
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hiroyuki Yamakita, Katsuhiko Kumagawa, Kazuo Inoue, Akinori Shiota, Ichiro Sato, Hiroshi Satani, Masanori Kimura, Satoshi Asada
  • Publication number: 20040109122
    Abstract: An array substrate (10) is provided with a pixel electrode (3) disposed in a region defined by two adjacent gate wirings (1) and two adjacent source wirings (2), a switching element (5) for switching a voltage applied to the pixel electrode (3) from the source wiring (2) based on a signal voltage supplied from the gate wiring (1), a common wiring (8) arranged between the two adjacent gate wirings (1) and a common electrode (4) being electrically connected to the common wiring (8) and generating an electric field between the pixel electrode (3) whereto a voltage is applied, wherein the pixel electrode (1) comprises a first pixel electrode (1a) and a second pixel electrode (2a), and the opposing electrode (2) comprises a first opposing electrode (1b) and a second opposing electrode (2b), wherein a first region generates an electric field between the first pixel electrode (1a) and the first opposing electrode (2a) whose light transmittance is lower than that of the first pixel electrode (1a) and a second region
    Type: Application
    Filed: October 7, 2003
    Publication date: June 10, 2004
    Inventors: Katsuhiko Kumagawa, Hiroyuki Yamakita, Masanori Kimura, Akio Takimoto