Patents by Inventor Takahiro Yajima

Takahiro Yajima 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: 6162988
    Abstract: The photovoltaic element of the present invention is a photovoltaic element comprised of a semiconductor-junctioned element, characterized in that the element includes a first electrically conductive type semiconductor layer, a non-crystalline i type semiconductor layer, a microcrystalline i type semiconductor layer and a microcrystalline second electrically conductive type semiconductor layer and is pin-junctioned, and a method of and an apparatus for manufacturing the same are characterized by efficiently and continuously mass-producing the photovoltaic element having an excellent current-voltage characteristic and excellent photoelectric conversion efficiency.
    Type: Grant
    Filed: September 4, 1997
    Date of Patent: December 19, 2000
    Assignee: Canon Kabushiki Kaisha
    Inventors: Shotaro Okabe, Yasushi Fujioka, Masahiro Kanai, Akira Sakai, Tadashi Sawayama, Yuzo Kohda, Tadashi Hori, Takahiro Yajima
  • Patent number: 6159300
    Abstract: An apparatus for forming a non-single-crystal semiconductor thin film comprising a film deposition chamber having a film-forming space surrounded by a film deposition chamber wall and a beltlike substrate, and an external chamber surrounding the deposition chamber wall is provided. While the beltlike substrate is moved in a longitudinal direction, a film-forming gas is introduced through a gas supply device into the film-forming space and microwave energy is radiated from a microwave applicator into the film-forming space to induce a microwave plasma, and thereby form a non-single-crystal semiconductor thin film on a surface of the beltlike substrate. A cooling mechanism and a temperature-increasing mechanism are provided to cover a part of an outside surface of the deposition chamber wall. An apparatus for forming a non-single-crystal semiconductor thin film where the gas supply device comprises a gas manifold set apart from the deposition chamber wall is another embodiment.
    Type: Grant
    Filed: December 15, 1997
    Date of Patent: December 12, 2000
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tadashi Hori, Shotaro Okabe, Akira Sakai, Yuzo Kohda, Takahiro Yajima
  • Patent number: 6159763
    Abstract: There is provided a method of forming a photovoltaic element, in which a p-type semiconductor layer is formed in a device for forming a semiconductor thin film having a cathod electrode structure, in which in a plasma discharge space, the surface area of a cathod electrode in a plasma discharge space is larger than the sum of surface areas of a belt-like member and an anode electrode, a potential of said cathod electrode at the time of excitation of glow discharge is positive relative to the belt-like member and the anode electrode, and a separator electrode partially constituting the cathod electrode is configured to have a form of a fin or a block, and an n-type semiconductor layer is formed in a device for forming a semiconductor thin film having a cathod electrode structure of a capacitive-coupling, parallel-plate type.
    Type: Grant
    Filed: September 10, 1997
    Date of Patent: December 12, 2000
    Assignee: Canon Kabushiki Kaisha
    Inventors: Akira Sakai, Yasushi Fujioka, Shotaro Okabe, Masahiro Kanai, Yuzo Kohda, Tadashi Hori, Takahiro Yajima
  • Patent number: 6153013
    Abstract: The deposited-film-forming apparatus of the present invention is an apparatus for forming deposited films while continuously passing a belt-like member through the insides of a plurality of vacuum chambers connected via connecting members and superposingly forming a plurality of different thin films on the surface of the belt-like member by plasma-assisted CVD, wherein the vacuum chambers are fixed to a stand for supporting the vacuum chambers, and a mechanism for relaxing stress acting in the transport direction of the belt-like member, generated in the vacuum chambers by the action of expansion and contraction due to thermal expansion of the vacuum chambers, is provided between each vacuum chamber and each connecting member.
    Type: Grant
    Filed: February 14, 1997
    Date of Patent: November 28, 2000
    Assignee: Canon Kabushiki Kaisha
    Inventors: Akira Sakai, Shotaro Okabe, Masahiro Kanai, Yuzo Kohda, Tadashi Hori, Tomonori Nishimoto, Takahiro Yajima
  • Patent number: 6025039
    Abstract: A photovoltaic cell comprising a substrate, an n-layer, an i-layer, and a p-layer, wherein the p-layer comprises a first p-layer including micro-crystals adjacent to the i-layer and a second, amorphous p-layer stacked on the first p-layer. A photovoltaic cell is provided in which carrier injection from the upper electrode into the p-layer can be suppressed to obtain a high open circuit voltage.
    Type: Grant
    Filed: September 24, 1996
    Date of Patent: February 15, 2000
    Assignee: Canon Kabushiki Kaisha
    Inventor: Takahiro Yajima
  • Patent number: 5927994
    Abstract: A method of manufacturing thin films by plasma CVD is described. This method comprises supplying power to a power electrode in a way such that a self-bias upon plasma discharge of the power applying electrode, which is situated in a plasma discharge space, is a positive potential relative to a ground electrode.
    Type: Grant
    Filed: January 13, 1997
    Date of Patent: July 27, 1999
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yuzo Kohda, Shotaro Okabe, Masahiro Kanai, Akira Sakai, Tadashi Hori, Tomonori Nishimoto, Takahiro Yajima
  • Patent number: 5897332
    Abstract: A method for manufacturing a photoelectric conversion element containing at least one pin junction, wherein a diffusion preventing layer is provided between an n-type layer and an i-type layer and/or between an i-type layer and a p-type layer, and the diffusion preventing layer is deposited such that deposition temperature differs in its thickness direction.
    Type: Grant
    Filed: September 23, 1996
    Date of Patent: April 27, 1999
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tadashi Hori, Shotaro Okabe, Masahiro Kanai, Akira Sakai, Yuzo Kohda, Tomonori Nishimoto, Takahiro Yajima
  • Patent number: 5769963
    Abstract: A photovoltaic device comprises a semiconductor region having at least one set of semiconductor layers comprised of a first semiconductor layer having a first conductivity type, an intrinsic or substantially intrinsic second semiconductor layer, and a third semiconductor layer having a conductivity type opposite to that of the first conductivity type, the layers being formed in this order, and first and second electrodes provided such that the electrodes interpose the semiconductor region; wherein the density of a dopant impurity determining the conductivity type of the first semiconductor layer in a set of semiconductor layers which is in contact with the first electrode is varied so as to be lower on the side of the first electrode, or the grain size of crystals in the first semiconductor layer is varied so as to be smaller on the side of the first electrode.
    Type: Grant
    Filed: August 30, 1996
    Date of Patent: June 23, 1998
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yasushi Fujioka, Shotaro Okabe, Masahiro Kanai, Akira Sakai, Yuzo Koda, Tadashi Hori, Tomonori Nishimoto, Takahiro Yajima
  • Patent number: 5720826
    Abstract: Provided are a photovoltaic element suitable for practical use, low in cost, high in reliability, and high in photoelectric conversion efficiency, and a fabrication process thereof. In the photovoltaic element having stacked layers of non-single-crystal semiconductors, at least an i-type semiconductor layer and a second conductivity type semiconductor layer are stacked on a first conductivity type semiconductor layer, and the second conduction type semiconductor layer has a layer A formed by exposing the surface of the i-type semiconductor layer to a plasma containing a valence electron controlling agent and a layer B deposited on the layer A by a CVD process using at least the valence electron controlling agent and the main constituent elements of the i-type semiconductor layer.
    Type: Grant
    Filed: May 29, 1996
    Date of Patent: February 24, 1998
    Assignee: Canon Kabushiki Kaisha
    Inventors: Ryo Hayashi, Yasushi Fujioka, Shotaro Okabe, Masahiro Kanai, Jinsho Matsuyama, Akira Sakai, Yuzo Koda, Tadashi Hori, Takahiro Yajima