Patents by Inventor Kohei Yokoyama

Kohei Yokoyama has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20080233669
    Abstract: A full-color light-emitting device is achieved with plural kinds of light-emitting elements in each of which a stacked layer of a first material layer formed selectively with a droplet discharge apparatus and a second material layer formed by vapor-deposition method using the conductive-surface plate on which a layer containing an organic compound is formed is provided between a pair of electrodes. The first material layer is a layer in which an organic compound and a metal oxide which is an inorganic compound are mixed. By adjusting the thickness of the first material layer of each light-emitting element, which is different depending on an emission color, a blue light emission component, a green light emission component, or a red light emission component among a plurality of components for white light emission can be selectively emphasized and taken out by light interference phenomenon.
    Type: Application
    Filed: March 18, 2008
    Publication date: September 25, 2008
    Inventors: Yoshiharu Hirakata, Yosuke Sato, Kohei Yokoyama, Hideaki Kuwabara, Shunpei Yamazaki
  • Publication number: 20070216293
    Abstract: It is an object of the present invention to provide a light-emitting material with high light emission intensity. It is another object to provide a light-emitting element with high light emission efficiency. Moreover, it is another object to provide a light-emitting device and an electronic appliance with reduced power consumption. A light-emitting material contains at least a light-emitting substance, a base material, and an additive which is an element belonging to group 14 of the periodic table or a compound containing two or more kinds of elements belonging to group 14, or a compound containing at least two or more kinds of elements each belonging to a different group chosen from group 13, group 14, and group 15. Due to the light-emitting material, a light-emitting element and an electronic appliance which has high light emission efficiency and can be driven at a low voltage can be obtained.
    Type: Application
    Filed: February 27, 2007
    Publication date: September 20, 2007
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Kohei YOKOYAMA, Yoshiaki YAMAMOTO, Junichiro SAKATA, Takahiro KAWAKAMI
  • Publication number: 20070205428
    Abstract: To provide a light-emitting material made of an inorganic compound, which exhibits higher luminance than the conventional material, due to its crystal structure. The light-emitting material includes a host material and an impurity element which serves as a luminescence center. The main crystal structure of the light-emitting material is hexagonal. The host material is a compound of a Group 2 element and a Group 16 element, or a compound of a Group 12 element and a Group 16 element. The impurity element includes at least one of manganese (Mn), samarium (Sm), terbium (Tb), erbium (Er), thulium (Tm), europium (Eu), cerium (Ce), and praseodymium (Pr).
    Type: Application
    Filed: February 27, 2007
    Publication date: September 6, 2007
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Miki KATAYAMA, Kohei YOKOYAMA, Junichiro SAKATA
  • Publication number: 20070205416
    Abstract: A light emitting element that can be driven at a low voltage is provided. Further, a light emitting device and an electronic device with reduced power consumption are provided. A light emitting element is provided that includes a substrate 100, and a first electrode 101, a first insulating layer 102, a light emitting layer 103, a second insulating layer 104, and a second electrode 105, which are over the substrate 100. The light emitting layer 103 includes a compound ABC2, referred to as a ‘chalcopyrite’ (wherein A is Cu or Ag, B is Al, Ga, or In, and C is S, Se, or Te). By employing such a structure, a light emitting element that can be driven at a low voltage can be provided.
    Type: Application
    Filed: February 27, 2007
    Publication date: September 6, 2007
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Junichiro SAKATA, Kohei YOKOYAMA, Yoshiaki YAMAMOTO, Takahiro KAWAKAMI
  • Publication number: 20070200112
    Abstract: It is an object of the present invention to provide a light-emitting device with high current efficiency and high display quality, in which a change in luminance with time is suppressed. The light-emitting device is provided with a plurality of light-emitting elements in each of which a plurality of light-emitting units each including at least one light-emitting layer are connected in series between a pair of electrodes. Between one of light-emitting units and the other light-emitting unit, an intermediate conductive layer is provided in the light-emitting unit. The light-emitting layer includes base material which is a compound containing an element belonging to group 2 and an element belonging to group 16 or a compound containing an element belonging to group 12 and an element belonging to group 16, and an impurity element which is an emission center. This structure makes it possible to increase light emission luminance without increasing current density.
    Type: Application
    Filed: February 16, 2007
    Publication date: August 30, 2007
    Inventors: Shunpei Yamazaki, Junichiro Sakata, Takahiro Kawakami, Yoshiaki Yamamoto, Miki Katayama, Kohei Yokoyama, Yasuyuki Arai
  • Publication number: 20070194321
    Abstract: It is an object of the present invention to provide a light emitting element which can be driven at a low voltage. Other objects of the present invention are to provide a light emitting element with a high luminescent efficiency; a light emitting element with a high luminance; a light emitting element having long-life luminescence; a light emitting element and an electronic device having reduced power consumption; and a light emitting element and an electronic device which can be manufactured at low cost. The light emitting element has a light emitting layer and a barrier layer between a first electrode and a second electrode, the light emitting layer contains a base material and an impurity element, and the barrier layer is provided so as to be in contact with the first electrode. Light emission is obtained when a voltage is applied such that a potential of the second electrode becomes higher than a potential of the first electrode.
    Type: Application
    Filed: February 9, 2007
    Publication date: August 23, 2007
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Shunpei YAMAZAKI, Junichiro SAKATA, Takahiro KAWAKAMI, Yoshiaki YAMAMOTO, Miki KATAYAMA, Kohei YOKOYAMA
  • Publication number: 20070194306
    Abstract: It is an object to provide a light emitting element capable of low-voltage driving; with high luminous efficiency; with high emission luminance; and with long emission lifetime. It is another object to provide a light emitting device and an electronic appliance in which power consumption is reduced; and which can be manufactured at low cost. A light emitting element is provided, including a light emitting layer and a layer including a composite material between a first electrode and a second electrode, where the light emitting layer includes a base material and an impurity element, the layer including the composite material includes an organic compound and an inorganic compound, the layer including the composite material is provided to be in contact with the second electrode, and light emission is obtained by application of a voltage so that an electric potential of the second electrode is higher than that of the first electrode.
    Type: Application
    Filed: February 13, 2007
    Publication date: August 23, 2007
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Shunpei YAMAZAKI, Junichiro SAKATA, Takahiro KAWAKAMI, Yoshiaki YAMAMOTO, Miki KATAYAMA, Kohei YOKOYAMA
  • Publication number: 20070190235
    Abstract: An object of the present invention is to provide a film forming method for forming a film with reduced defect and to provide a film forming method for forming a film with a uniform quality. In addition, another object is to provide a manufacturing method of a light emitting element which can be driven with low voltage. Further, another object is to provide a manufacturing method of a light emitting element with high light emission efficiency. A film with reduced defect and a uniform quality can be formed by fixing a substrate to a substrate holding unit so that at least a part of a surface of the substrate is exposed, evaporating a vapor deposition material from an evaporation source filled with the vapor deposition material, irradiating the vapor deposition material which is evaporated with a laser beam, and depositing the vapor deposition material on the surface of the substrate.
    Type: Application
    Filed: February 5, 2007
    Publication date: August 16, 2007
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Shunpei YAMAZAKI, Junichiro SAKATA, Yoshiaki YAMAMOTO, Miki KATAYAMA, Kohei YOKOYAMA, Rie MATSUBARA, Takahiro KAWAKAMI
  • Publication number: 20070187699
    Abstract: A light emitting element is provided, which comprises a pair of electrodes, a p-type semiconductor layer, and an n-type semiconductor layer. The p-type semiconductor layer and the n-type semiconductor layer are interposed between the pair of electrodes. The p-type semiconductor layer includes a first sulfide, and the n-type semiconductor layer includes a second sulfide. At least one of the p-type semiconductor layer and the n-type semiconductor layer includes a light emitting center.
    Type: Application
    Filed: February 6, 2007
    Publication date: August 16, 2007
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Junichiro SAKATA, Yoshiaki YAMAMOTO, Takahiro KAWAKAMI, Kohei YOKOYAMA, Miki KATAYAMA, Rie MATSUBARA
  • Publication number: 20070176536
    Abstract: An object is to provide a novel light emitting material. Another object is to provide a light emitting device and an electronic device with reduced power consumption. Still another object is to provide a light emitting device and an electronic device which can be manufactured at low cost. Provided is a light emitting element including a base material, a first impurity element, a second impurity element, and a third impurity element. The base material is one of ZnS, CdS, CaS, Y2S3, Ga2S3, SrS, BaS, ZnO, Y2O3, AlN, GaN, InN, ZnSe, ZnTe, and SrGa2S4; the first impurity element is any of Cu, Ag, Au, Pt, and Si; the second impurity element is any of F, Cl, Br, I, B, Al, Ga, In, and Tl; and the third impurity element is any of Li, Na, K, Rb, Cs, N, P, As, Sb, and Bi.
    Type: Application
    Filed: January 19, 2007
    Publication date: August 2, 2007
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Junichiro SAKATA, Takahiro KAWAKAMI, Yoshiaki YAMAMOTO, Miki KATAYAMA, Kohei YOKOYAMA
  • Publication number: 20060167269
    Abstract: The present invention relates to compounds according to the formula (I): Where RA is a C1-C10 substituted or unsubstituted linear, branch-chained or cyclic alkyl or alkenyl group or a phenyl group according to the formula (II): RB is a C1-C10 substituted or unsubstituted linear, branch-chained or cyclic alkyl or alkenyl group or a phenyl group of the formula (III): R1, R2, R3, R4, R5, R6, R7, R8, R9 and R10 are each independently selected from H, C1-C10 (preferably a C1-C4) alkyl or alkenyl group, CF3, F, Cl, Br, I, CN, NO2, NH2, NHR, NRR, COR (acyl group), OR (hydroxyl or ether group), CO2R (carboxylic acid or ester group), or COSR (thioester group) where R is H or a C1-C10 (preferably a C1-C4) alkyl or alkenyl group, an unsubstituted or substituted aryl (preferably, phenyl) or heterocycle group, or a (IV) group, where R3 is H, a C1-C10 (preferably a C1-C4) alkyl, alkenyl, ether or a thioether group; and R11 and R12 are independently selected from H or a C1-C3 alkyl or alkenyl group, or a pharmaceutically ac
    Type: Application
    Filed: July 11, 2002
    Publication date: July 27, 2006
    Inventors: Andrew Hamilton, Wesley Van Voorhis, Kohei Yokoyama, Fredericks Bucker, Junko Ohkanda, Michael Gelb, Jeffrey Lockman