Patents by Inventor Tadaaki Hirai

Tadaaki Hirai 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: 4884011
    Abstract: A light-detecting device for converting a light to an electrical signal utilizes a charge multiplication function and has a stable gain.The light-detecting device comprises a photo-electric conversion unit for converting a measurement light to an electrical signal, a power supply for applying an electric field to the photo-electric conversion unit, a light source for applying an incident light to the photo-electric conversion unit, signal detection means for detecting the charge converted by the photo-electric conversion unit based on the incident light from the light source, and signal hold means for holding the output signal of the signal detection means at a predetermined level.
    Type: Grant
    Filed: January 13, 1988
    Date of Patent: November 28, 1989
    Assignee: Hitachi, Ltd. & Nippon Hoso Kasai
    Inventors: Tatsuo Makishima, Tadaaki Hirai, Kazutaka Tsuji, Sachio Ishioka, Takashi Yamashita, Keiichi Shidara, Junichi Yamazaki, Masaaki Aiba
  • Patent number: 4866332
    Abstract: A target of an image pickup tube, having a transparent substrate, a transparent conductive film, a p-type photoconductive film made mainly from amorphous Se, and an n-type conductive film capable of forming a rectifying contact at the interface with the p-type photoconductive film, using the rectifying contact as a reverse bias, characterized in that the p-type photoconductive film containing at least a region having more than 35%, and to 60% by weight of Te in the film thickness direction, and at least a region containing 0.005 to 5% by weight of at least a material capable of forming shallow levels in the amorphous Se in the film thickness direction, has good after-image characteristics even if operated at a high temperature.
    Type: Grant
    Filed: February 19, 1987
    Date of Patent: September 12, 1989
    Assignees: Hitachi, Ltd., Nippon Hoso Kyokai
    Inventors: Yukio Takasaki, Tatsuo Makishima, Kazutaka Tsuji, Tadaaki Hirai, Eisuke Inoue, Yasuhiko Nonaka, Naohiro Goto, Masanao Yamamoto, Keiichi Shidara, Kenkichi Tanioka, Takashi Yamashita, Tatsuro Kawamura, Eikyuu Hiruma, Shirou Suzuki, Masaaki Aiba
  • Patent number: 4860093
    Abstract: The present invention relates to a method and an apparatus for driving image pick-up tubes in, particular, a color television camera or the like having more than one image pick-up tube and in particular to a method and an apparatus for driving image pick-up tubes in which the potentials of the cathode electrodes of the respective image pick-up tubes are set to the same common potential, the potential of the target electrode of at least one of the image pick-up tubes is set substantially to earth potential, target drive potentials are individually applied to the target electrodes of the other image pick-up tubes, and the target potential of each image pick-up tube is set to a value near the earth potential, so that a high S/N ratio is obtained. The driving appartatus can be miniaturized and easily driven. According to the invention, a capacitor, such as a chip capcitor or the like, with a low withstanding voltage can be used in a first-stage amplifier to amplify the video signal from the target electrode.
    Type: Grant
    Filed: January 13, 1988
    Date of Patent: August 22, 1989
    Assignees: Hitachi, Ltd., Nippon Hoso Kyokai
    Inventors: Takashi Yamashita, Keiichi Shidara, Masaaki Aiba, Yukio Takasaki, Tadaaki Hirai
  • Patent number: 4829345
    Abstract: Within an electronic device having a plurality of circuit parts (such as a three-dimensional device), a light transmission system which transfers signals between the circuit parts by the use of light is provided.The light transmission system is formed of a light emitting source which emits light having a desired wavelength, a photoelectric conversion portion which absorbs the light and converts it into an electric signal, and a light traveling path which conveys the light emitted from the light emitting source to the photoelectric conversion portion.Further, each of the light emitting source, the light traveling path and the photoelectric conversion portion is formed of a superlattice structure in which a plurality of materials of unequal energy gaps are layered.
    Type: Grant
    Filed: April 29, 1986
    Date of Patent: May 9, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Sachio Ishioka, Kazutaka Tsuji, Yukio Takasaki, Yasuharu Shimomoto, Hirokazu Matsubara, Tadaaki Hirai
  • Patent number: 4636682
    Abstract: A high velocity electron beam scanning negatively charge biased image pickup tube has a target which includes at least a transparent conductive layer, a photoconductor layer and a layer for secondary electron emission on a light-transmissive insulating substrate, and in which the transparent conductive layer is arranged on a light incidence side, the photoconductor layer being made of amorphous silicon.
    Type: Grant
    Filed: May 5, 1983
    Date of Patent: January 13, 1987
    Assignee: Hitachi, Ltd.
    Inventors: Chushirou Kusano, Sachio Ishioka, Yoshinori Imamura, Yukio Takasaki, Hirofumi Ogawa, Tatsuo Makishima, Tadaaki Hirai
  • Patent number: 4626885
    Abstract: A photosensor including a transparent electrode for transmitting incident light and a photoconductive layer receiving light from the transparent electrode for performing photoelectric conversion, is disclosed in which the photoconductive layer is made of amorphous silicon, the amorphous silicon contains 5 to 30 atomic percent hydrogen and is doped with at least one selected from elements belonging to the groups II and III in such a manner that a region remote from the transparent electrode is higher in the concentration of the selected element than another region proximate to the transparent electrode, and a voltage is applied across the photoconductive layer so that a surface of the photoconductive layer facing the transparent electrode is at a positive potential with respect to another surface of the photoconductive layer opposite to the surface facing the transparent electrode.
    Type: Grant
    Filed: July 29, 1983
    Date of Patent: December 2, 1986
    Assignee: Hitachi, Ltd.
    Inventors: Sachio Ishioka, Yoshinori Imamura, Tsuyoshi Uda, Yukio Takasaki, Chushirou Kusano, Hirofumi Ogawa, Tatsuo Makishima, Tadaaki Hirai
  • Patent number: 4617248
    Abstract: A structure of a photoconductive film related to a target of an image pickup tube of the photo conductivity type is disclosed. This photoconductive film is formed from mainly Se and Te is added in a central part thereof. Further, As, which is considered to form a deep trap level which captures electrons in Se and GaF.sub.3, etc. which form negative space charges by capturing electrons in Se are added in the region adjacent to the region where Te exists. In addition, a thickness of film in the region where GaF.sub.3, etc. exists is selected to be thinner (not smaller than 20 .ANG. and not larger than 90 .ANG.) than a value which has been adopted so far.
    Type: Grant
    Filed: May 20, 1985
    Date of Patent: October 14, 1986
    Assignees: Nippon Hoso Kyokai, Hitachi, Ltd.
    Inventors: Kenkichi Tanioka, Keiichi Shidara, Takao Kuriyama, Yukio Takasaki, Tadaaki Hirai, Yasuhiko Nonaka, Eisuke Inoue
  • Patent number: 4564784
    Abstract: An image pickup tube comprising a target composed of a light-transmissible plate, a transparent electrode provided on said light-transmissible plate and a photoconductor made of hydrogen-containing amorphous silicon provided on said transparent electrode; an electron beam generator; and a mesh electrode near the aforesaid target, at least the surface of said mesh electrode being made of at least one member selected from the group consisting of Be, B, C, Mg, Al and Si, has high resolution with greatly improved life characteristics.
    Type: Grant
    Filed: November 16, 1983
    Date of Patent: January 14, 1986
    Assignee: Hitachi, Ltd.
    Inventors: Sachio Ishioka, Yoshinori Imamura, Tadaaki Hirai, Saburo Nobutoki, Akio Maruyama
  • Patent number: 4556817
    Abstract: An image pickup tube of high velocity electron beam scanning and negatively charging system having a target including, on a transparent substrate, at least a transparent conductive film, a photoconductive layer, a layer for emitting secondary electrons, and stripe electrodes. The transparent substrate may be made of amorphous silicon.
    Type: Grant
    Filed: November 2, 1983
    Date of Patent: December 3, 1985
    Assignee: Hitachi, Ltd.
    Inventors: Chushirou Kusano, Sachio Ishioka, Yoshinori Imamura, Yukio Takasaki, Hirofumi Ogawa, Tatsuo Makishima, Tadaaki Hirai, Eiichi Maruyama
  • Patent number: 4556816
    Abstract: Disclosed is a photoelectric device having at least a signal electrode, and an amorphous photoconductor layer whose principal constituent is silicon and which contains hydrogen as an indispensable constituent element, the amorphous photoconductor layer being disposed in adjacency to the signal electrode, characterized by comprising a thin layer interposed between the signal electrode and the amorphous photoconductor layer, the thin layer being made of an inorganic material whose principal constituent is at least one compound selected from the group consisting of oxides of at least one element selected from the group that consists of Si, Ti, Al, Mg, Ba, Ta, Bi, V, Ni, Th, Fe, La, Be, Sc and Co, nitrides of at least one element selected from the group that consists of Ga, Si, Mg, Te, Hf, Zr, Nb and B, and halides of at least one element selected from the group that consists of Na, Mg, Li, Ba, Ca and K.
    Type: Grant
    Filed: July 5, 1983
    Date of Patent: December 3, 1985
    Assignee: Hitachi, Ltd.
    Inventors: Yoshinori Imamura, Saburo Ataka, Yukio Takasaki, Yasuo Tanaka, Tadaaki Hirai, Eiichi Maruyama
  • Patent number: 4429325
    Abstract: In a photosensor having a metal electrode, at least one photoelectric conversion layer which overlies the metal electrode, and a transparent or partly transparent conductive layer which overlies the photoelectric conversion layer, a recombination layer for recombining electrons and holes is disposed between the metal electrode and the photoelectric conversion layer. By disposing the recombination layer, the metal electrode having an insulating oxide film on its surface can be handled as if the insulating oxide film were not existent. The dark current is suppressed, and the photo-response is made good. As the materials of the recombination layer, Sb.sub.2 S.sub.3, As.sub.2 Se.sub.3, As.sub.2 S.sub.3, Sb.sub.2 Se.sub.3 etc. are typical.
    Type: Grant
    Filed: November 14, 1980
    Date of Patent: January 31, 1984
    Assignee: Hitachi, Ltd.
    Inventors: Yukio Takasaki, Tadaaki Hirai, Hideaki Yamamoto, Toshihisa Tsukada, Yoshiaki Mori
  • Patent number: 4394749
    Abstract: A photoelectric device having at least a predetermined impurity region which is disposed in a semiconductor substrate, and a photoelectric conversion portion which is constructed by stacking an electrode layer lying in contact with at least a part of the impurity region, a photoconductive material layer overlying the electrode layer, and a transparent electrode overlying the photoconductive material layer, characterized in that the photoconductive material layer is made of an amorphous chalcogenide material which principally contains Se, is disclosed. It is very favorable that the photoelectric conversion material layer made of the amorphous material principally containing Se is partially doped with Te so as to enhance its sensitivity. The amorphous chalcogenide material is very useful in the following point.
    Type: Grant
    Filed: May 30, 1980
    Date of Patent: July 19, 1983
    Assignee: Hitachi, Ltd.
    Inventors: Toshihisa Tsukada, Yukio Takasaki, Tadaaki Hirai, Toru Baji, Hideaki Yamamoto, Yasuo Tanaka, Eiichi Maruyama, Sachio Ishioka
  • Patent number: 4331506
    Abstract: A method of manufacturing a target of an image pickup tube comprising the steps of: forming a plurality of groups of transparent conductive signal electrodes on a transparent insulating base plate; forming a first layer on at least a portion constituting an image area of the image pickup tube, said first layer being substantially insoluble in etching liquid used for etching an insulating layer to constitute an intermediate layer insulator in a double layered interconnection structure; forming, after formation of said first layer, an insulating layer to constitute said intermediate-layer insulator; removing a predetermined portion of said insulating layer, removing said first layer together with said insulating layer located thereon; forming bus bars; and forming a photoconductive layer on said plurality of groups of the transparent conductive signal electrodes.This invention provides an excellent method for mass production.
    Type: Grant
    Filed: December 2, 1980
    Date of Patent: May 25, 1982
    Assignees: Hitachi, Ltd., Hitachi Denshi Kabushiki Kaisha
    Inventors: Akira Sasano, Toshio Nakano, Ken Tsutsui, Chushiro Kusano, Tadaaki Hirai, Eiichi Maruyama
  • Patent number: 4330733
    Abstract: A photoconductive target having an electrode and a P-type conductive layer mainly made of Se and making rectifying contact at an interface with the electrode, with at least Te being doped in a portion of the P-type conductive layer. At least one metal fluoride forming shallow levels is doped in the region where the signal current is generated for the most part of the P-type conductive layer with an average concentration of not less than 50 ppm and not more than 5% by weight. The metal fluoride is preferably at least one selected from the group consisting of LiF, NaF, MgF.sub.2, CaF.sub.2, BaF.sub.2, AlF.sub.3, CrF.sub.3, MnF.sub.2, CoF.sub.2, PbF.sub.2, CeF.sub.3 and TlF. The high light sticking of the photoconductive target can thus be considerably reduced.
    Type: Grant
    Filed: May 22, 1980
    Date of Patent: May 18, 1982
    Assignees: Nippon Hoso Kyokai, Hitachi, Ltd.
    Inventors: Keiichi Shidara, Naohiro Goto, Tatsuro Kawamura, Eikyu Hiruma, Yohitsumu Ikeda, Kenkichi Tanioka, Tadaaki Hirai, Yukio Takasaki, Chushirou Kusano, Tsuyoshi Uda, Yasuhiko Nonaka
  • Patent number: 4323912
    Abstract: In a solid-state imaging device having a semiconductor integrated circuit in which a plurality of switching elements for addressing positions of picture elements and scanning circuitry for turning the switching elements "on" and "off" in time sequence are disposed on an identical substrate, a photoconductive film which is disposed on the integrated circuit and which is connected with the respective switching elements, and a light transmitting electrode which is disposed on the photoconductive film, a voltage being applied to the light transmitting electrode thereby to bias a region of the photoconductive film on a light entrance side either positively or negatively with respect to a region thereof on the opposite side; a solid-state imaging device characterized in that said each switching element is an element which uses carriers of a polarity opposite to that of carriers having a greater mobility in said photoconductive film.
    Type: Grant
    Filed: May 23, 1980
    Date of Patent: April 6, 1982
    Assignee: Hitachi, Ltd.
    Inventors: Norio Koike, Toshihisa Tsukada, Haruhisa Ando, Hideaki Yamamoto, Tadaaki Hirai, Masaharu Kubo, Eiichi Maruyama, Toru Baji, Yukio Takasaki, Shusaku Nagahara
  • Patent number: 4307319
    Abstract: A photoelectric device comprises a signal electrode, a layer of amorphous photoconductor containing 50 atomic percent or more of selenium and an N-type semiconductor layer made of a material selected from the group consisting of oxygen depletion type cerium oxide and oxygen depletion type lead oxide and disposed therebetween, which has a thickness greater than 8 nm and up to and including 500 nm and a Fermi level located within an energy range of 0.2 to 0.8 eV from the bottom of a conduction band.
    Type: Grant
    Filed: July 5, 1978
    Date of Patent: December 22, 1981
    Assignees: Hitachi, Ltd., Nippon Hoso Kyokai
    Inventors: Motoyasu Terao, Tadaaki Hirai, Eiichi Maruyama, Hideaki Yamamoto, Tsutomu Fujita, Naohiro Goto, Keiichi Shidara
  • Patent number: 4255686
    Abstract: In a photosensor having at least a light-transmitting conductive layer which is arranged on the side of light incidence, and a photoconductive layer in which charges are stored in correspondence with the light incidence; a photosensor characterized in that at least a region of said photoconductive layer for storing the charges is made of an amorphous material which contains hydrogen and silicon as indispensable constituent elements thereof, in which the silicon amounts to at least 50 atomic % and the hydrogen amounts to at least 10 atomic % and at most 50 atomic %, and whose resistivity is not lower than 10.sup.10 .OMEGA..multidot.cm.
    Type: Grant
    Filed: May 16, 1979
    Date of Patent: March 10, 1981
    Assignee: Hitachi, Ltd.
    Inventors: Eiichi Maruyama, Yoshinori Imamura, Saburo Ataka, Kiyohisa Inao, Yukio Takasaki, Toshihisa Tsukada, Tadaaki Hirai
  • Patent number: 4249106
    Abstract: A radiation sensitive screen comprising a crystalline silicon substrate which is located on a side of incidence of radiation, and an amorphous silicon film which contains hydrogen and which is located on the opposite side of the substrate to the side of the incidence of the radiation. The radiation sensitive screen of this invention can be manufactured by a simple method, and can achieve a high resolution. It is useful for the target of an image pickup tube, the electron bombardment target of an X-ray fluorescence multiplier tube, etc.
    Type: Grant
    Filed: November 7, 1979
    Date of Patent: February 3, 1981
    Assignee: Hitachi, Ltd.
    Inventors: Eiichi Maruyama, Saburo Ataka, Kiyohisa Inao, Yoshinori Imamura, Toshihisa Tsukada, Yukio Takasaki, Tadaaki Hirai
  • Patent number: 4233506
    Abstract: A pboto-sensor wherein a bundle of optical fibers is disposed within a predetermined substrate, the optical fiber bundle extending from a first surface to a second surface of the substrate and being formed to be flat, an array of photosensitive elements which have photosensitive parts on an open end face of the optical fibers at the first surface of the substrate is disposed integrally with the substrate, and an end face of the optical fibers at the second surface of the substrate serves as an information reading surface.
    Type: Grant
    Filed: May 5, 1978
    Date of Patent: November 11, 1980
    Assignees: Nippon Telegraph and Telephone Public Corporation, Hitachi, Ltd.
    Inventors: Hideaki Yamamoto, Makoto Matsui, Toshihisa Tsukada, Yoshizumi Eto, Tadaaki Hirai, Eiichi Maruyama
  • Patent number: 4227078
    Abstract: A photo-sensor wherein a bundle of optical fibers in the form of a sheet is disposed within a predetermined substrate, the optical fiber bundle extending from a first surface to a second surface of the substrate, an array of photosensitive elements is disposed integrally with the substrate in such a manner that at least one transparent insulating layer intervenes between the photoelectric elements and the optical fiber bundle on, at least, an end face of the optical fiber bundle on the first surface side of the substrate, and an end face of the optical fiber bundle open to the second surface of the substrate serves as an information reading face.
    Type: Grant
    Filed: June 22, 1978
    Date of Patent: October 7, 1980
    Assignees: Nippon Telegraph and Telephone Public Corporation, Hitachi, Ltd.
    Inventors: Hideaki Yamamoto, Haruo Matsumaru, Makoto Matsui, Toshihisa Tsukada, Tadaaki Hirai, Eiichi Maruyama