Patents by Inventor Takuo Yamashita

Takuo Yamashita 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: 5334250
    Abstract: A vapor deposition apparatus for depositing thin film on substrates in which solid starting materials are used. In this apparatus, a carrier gas flows up and down in the same direction as gas convection, such that the effect of gas convection is minimized and film thickness and impurity concentration are uniform over the substrate surface. This uniformity is achieved by orienting a main reaction tube in a vertical direction, attaching two branch reaction tubes at the top of the main reaction tube, and venting carrier gas out the bottom of the main reaction tube. Alternately, the main reaction tube can be oriented horizontally, with the substrates being carried on a holder within a container having pores on its top and bottom.
    Type: Grant
    Filed: February 17, 1993
    Date of Patent: August 2, 1994
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Akiyoshi Mikami, Takashi Ogura, Kousuke Terada, Masaru Yoshida, Takuo Yamashita, Koichi Tanaka, Katsushi Okibayashi, Shigeo Nakajima, Hiroaki Nakaya, Kouji Taniguchi
  • Patent number: 5283132
    Abstract: An organic electroluminescent device for white luminescence, which includes a pair of opposite electrodes at least one of which is transparent, a hole transport layer and a luminescent layer. The layers are stacked in that order between the electrodes, the hole transport layer being formed from bis-di(p-tolyl)aminophenyl-1, 1-cyclohexane, and the luminescent layer being formed from a material having a luminescent peak at 460-480 nm and a thickness of 100-300 .ANG..
    Type: Grant
    Filed: March 11, 1992
    Date of Patent: February 1, 1994
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Takashi Ogura, Takuo Yamashita, Masaru Yoshida, Kazuhiro Emoto, Shigeo Nakajima
  • Patent number: 5264714
    Abstract: A thin-film electroluminescence device has transparent electrodes formed on a transparent substrate, a lower dielectric layer formed on the substrate having the transparent electrodes, a luminescent layer formed on the lower dielectric layer, an upper dielectric layer formed on the luminescent layer, and back electrodes formed on the upper dielectric layer. At least one of the upper and lower dielectric layers includes a SiN:H film formed in contact with the luminescent layer by a plasma chemical vapor deposition method. The SiN:H film contains N--H bonds of 1.2.times.10.sup.22 /cm.sup.3 or less to control an amount of change in emission-start voltage to 30 V or less.
    Type: Grant
    Filed: October 3, 1991
    Date of Patent: November 23, 1993
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Hiroaki Nakaya, Takuo Yamashita, Takashi Ogura, Masaru Yoshida
  • Patent number: 5194777
    Abstract: A method for fabricating an electroluminescence display device is disclosed. The fabricating method includes steps of forming at least one transparent front electrode on a transparent substrate, forming a lower electrically insulating layer on the front electrode, forming an emitting layer of an electroluminescent material on the lower electrically insulating layer, forming an upper electrically insulating layer on the emitting layer, and forming at least one rear electrode on the upper electrically insulating layer. In the fabricating method, at least one of the lower and upper electrically insulating layers is composed of at least one film of Si.sub.x N.sub.y O.sub.z :H, and the si.sub.x N.sub.y O.sub.z :H film is formed by the plasma chemical vapor deposition method.
    Type: Grant
    Filed: January 17, 1990
    Date of Patent: March 16, 1993
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Hiroaki Nakaya, Takuo Yamashita, Takashi Ogura, Masaru Yoshida
  • Patent number: 5189405
    Abstract: A thin film electroluminescent panel includes a transparent substrate with an electroluminescent element formed on the substrate. There is a moisture proof sheet to cover the electroluminescent element. The moisture proof sheet includes a metal layer laminated between the two resin films. The periphery of the moisture proof sheet is adhered to the transparent substrate. There is a moisture proof sheet with a moisture absorbent powder thereon, located between the electroluminescent element and the moisture proof sheet. The combination prevents moisture from affecting the operation of the electroluminescent element and provides for stability.
    Type: Grant
    Filed: December 23, 1991
    Date of Patent: February 23, 1993
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Takuo Yamashita, Takashi Ogura, Hiroaki Nakaya, Masaru Yoshida
  • Patent number: 5147683
    Abstract: Disclosed is an improvement of the chemical vapor deposition (CVD) process for preparing an electroluminescent device having a large area and a large size. The process includes forming a luminescent layer on a substrate by a reduced-pressure chemical vapor deposition method wherein a source material gas is introduced into a reaction chamber. The reaction chamber includes a screening means which screens the source material gas flow in the chamber to form a first area in which the gas is flowing and a second area in which the gas substantially does not flow. The screening means has apertures for connecting the first area and second area. the substrate is placed in the second area, to which the source material is supplied by means of gas diffusion.
    Type: Grant
    Filed: January 8, 1991
    Date of Patent: September 15, 1992
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Koichi Tanaka, Akiyoshi Mikami, Kouji Taniguchi, Katsushi Okibayashi, Kousuke Terada, Takuo Yamashita, Takashi Ogura, Hiroaki Nakaya, Masaru Yoshida, Shigeo Nakajima
  • Patent number: 5124204
    Abstract: Disclosed is a thin film EL panel having a high reliability. The thin film El panel is thin, light, and is made at a low cost. The present invention provides in a thin film electroluminescent (EL) panel comprising a light permeable base plate, a thin film EL element formed on the base plate and a moisture-proof sheet covered thereon, an improvement residing in that a moisture-absorption sheet is placed between said thin film EL element and said moisture-proof sheet, and said moisture-absorption sheet comprises an organic polymer sheet with silica gel powder dispersed therein at a certain surface density. The present invention also provides in a thin film electroluminescent (EL) panel comprising a light permeable base plate, a thin film EL element formed on the base plate and a moisture-proof sheet covered thereon, an improvement residing in that a moisture-absorption layer is formed on the inside surface of the moisture-proof sheet by coating powder thereon having moisture absorption properties.
    Type: Grant
    Filed: March 29, 1991
    Date of Patent: June 23, 1992
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Takuo Yamashita, Masaru Yoshida, Shigeo Nakajima, Keiichi Uno, Yoshiki Murakami
  • Patent number: 5116640
    Abstract: A process for preparing an electroluminescent device includes the steps of forming an insulating layer and a luminescent layer on a substrate, wherein the insulating and luminescent layers are respectively formed at different forming areas in the same deposition chamber.
    Type: Grant
    Filed: October 10, 1990
    Date of Patent: May 26, 1992
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Akiyoshi Mikami, Takashi Ogura, Kousuke Terada, Masaru Yoshida, Takuo Yamashita, Koichi Tanaka, Katsushi Okibayashi, Shigeo Nakajima, Hiroaki Nakaya, Kouji Taniguchi
  • Patent number: 5096735
    Abstract: Disclosed is an improvement of a process for producing a thin film electroluminescent device wherein the luminescent film is formed by a CVD method. The improvement residues in that an unnecessary portion of the luminescent layer, which is inherently formed if the CVD method is employed, is removed by etching.
    Type: Grant
    Filed: February 5, 1991
    Date of Patent: March 17, 1992
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Hiroaki Nakaya, Takuo Yamashita, Takashi Ogura, Kouji Tanaguchi, Koichi Tanaka, Akiyoshi Mikami, Katsushi Okibayashi, Kousuke Terada
  • Patent number: 5055360
    Abstract: A thin film EL device includes a translucent substrate; a first electrode layer disposed on the upper surface of the translucent substrate; a light emitting layer provided above the first electrode layer. A second electrode layer is provided above the light emitting layer and is electrically connected to the first electrode layer through an applied power source for applying electric field to the light emitting layer. Further one or more insulating layers is provided among the light emitting layer and the first electrode layer and/or the second electrode layer. At least one of the insulating layers is a composite layer of an inorganic film and an organic film and another insulating layer is a composite layer or an inorganic film in which the inorganic film is interposed between the light emitting layer and the organic film.
    Type: Grant
    Filed: June 8, 1989
    Date of Patent: October 8, 1991
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Takashi Ogura, Takuo Yamashita, Hiroaki Nakaya, Masaru Yoshida
  • Patent number: 4977350
    Abstract: A color electroluminescence display panel includes a substrate, a plurality of first and second electrodes disposed orthogonal to each other on the substrate, a luminescence layer interposed between the first and second electrodes, and insulating layers interposed between the electrodes and the luminescence layer, the luminescence layer having a plurality of luminescence layer groups each including a plurality of layer portions of different color luminescence, the first electrodes having a plurality of electrode groups corresponding in number to the luminescence layer groups, each first electrode group including a plurality of electrodes corresponding to the plural layer portions, the electrode groups alternately extending to opposite end portions of the substrate, and the extending end portions of the first electrode and the second electrode being supplied with a luminescence signal therebetween.
    Type: Grant
    Filed: May 11, 1989
    Date of Patent: December 11, 1990
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Koichi Tanaka, Takuo Yamashita, Satoshi Yamaue, Hiroaki Nakaya
  • Patent number: 4908603
    Abstract: A light-emitting alarm board uses thin-film EL elements which emit light of different colors individually or simultaneously, depending on the voltages applied thereon, thereby serving as display lamps for indicating the conditions of operation of a system being monitored.
    Type: Grant
    Filed: April 11, 1989
    Date of Patent: March 13, 1990
    Inventors: Satoshi Yamaue, Koichi Tanaka, Hiroaki Nakaya, Takuo Yamashita, Masaru Yoshida
  • Patent number: 4721631
    Abstract: According to a method of this invention for manufacturing a thin-film electroluminescent display panel of the type having a pair of electrodes sandwiching a three-layer structure composed of a layer covered with dielectric layers on both sides, a silicon nitride or silicon oxynitride film is formed on a layer comprising ZnS by a plasma chemical vapor deposition method with a mixture of silicon and nitrogen gases or of silicon, nitrogen and N.sub.2 O gases. Alternatively, this film may be formed in a double-layer structure, the second layer being formed with a mixture of silicon and ammonia gases or of silicon, ammonia and N.sub.2 O gases. A dielectric layer thus formed by a method embodying this invention can satisfactorily cover the protrusions and impurities in the layer underneath and thin-film electroluminescent elements manufactured by this method have superior brightness characteristics.
    Type: Grant
    Filed: March 9, 1987
    Date of Patent: January 26, 1988
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yoshihiro Endo, Takuo Yamashita, Ikuo Ogawa