Patents by Inventor Tomoko Mochizuki
Tomoko Mochizuki 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).
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Patent number: 7816866Abstract: A semiconductor photocathode 1 includes: a transparent substrate 11; a first electrode 13, formed on the transparent substrate 11 and enabling passage of light that has been transmitted through the transparent substrate 11; a window layer 14, formed on the first electrode 13 and formed of a semiconductor material with a thickness of no less than 10 nm and no more than 200 nm; a light absorbing layer 15, formed on the window layer 14, formed of a semiconductor material that is lattice matched to the window layer 14, is narrower in energy band gap than the window layer 14, and in which photoelectrons are excited in response to the incidence of light; an electron emission layer 16, formed on the light absorbing layer 15, formed of a semiconductor material that is lattice matched to the light absorbing layer 15, and emitting the photoelectrons excited in the light absorbing layer 15 to the exterior from a surface; and a second electrode 18, formed on the electron emission layer.Type: GrantFiled: October 25, 2006Date of Patent: October 19, 2010Assignee: Hamamatsu Photonics K.K.Inventors: Kazutoshi Nakajima, Minoru Niigaki, Tomoko Mochizuki, Toru Hirohata
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Patent number: 7365356Abstract: The invention relates to a photocathode having a structure that permits a decrease in the radiant sensitivity at low temperatures is suppressed so that the S/N ratio is improved. In the photocathode, a light absorbing layer is formed on the upper layer of a substrate. An electron emitting layer is formed on the upper layer of the light absorbing layer. A contact layer having a striped-shape is formed on the upper layer of the electron emitting layer. A surface electrode composed of metal is formed on the surface of the contact layer. The interval between bars in the contact layer is adjusted so as to become 0.2 ?m or more but 2 ?m or less.Type: GrantFiled: February 11, 2005Date of Patent: April 29, 2008Assignee: Hamamatsu Photonics K.K.Inventors: Toru Hirohata, Minoru Niigaki, Tomoko Mochizuki, Masami Yamada
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Publication number: 20070096648Abstract: A semiconductor photocathode 1 includes: a transparent substrate 11; a first electrode 13, formed on the transparent substrate 11 and enabling passage of light that has been transmitted through the transparent substrate 11; a window layer 14, formed on the first electrode 13 and formed of a semiconductor material with a thickness of no less than 10 nm and no more than 200 nm; a light absorbing layer 15, formed on the window layer 14, formed of a semiconductor material that is lattice matched to the window layer 14, is narrower in energy band gap than the window layer 14, and in which photoelectrons are excited in response to the incidence of light; an electron emission layer 16, formed on the light absorbing layer 15, formed of a semiconductor material that is lattice matched to the light absorbing layer 15, and emitting the photoelectrons excited in the light absorbing layer 15 to the exterior from a surface; and a second electrode 18, formed on the electron emission layer.Type: ApplicationFiled: October 25, 2006Publication date: May 3, 2007Inventors: Kazutoshi Nakajima, Minoru Niigaki, Tomoko Mochizuki, Toru Hirohata
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Patent number: 7176625Abstract: Provided are a photocathode plate capable of stably achieving a high sensitive property, and an electron tube using such a photocathode plate. In a photomultiplier tube 1, an insulating layer 63 is formed between a semiconductor electron emission layer 51 in a photocathode plate 23A, and a first electrode 65 electrically connected to an electron releasing portion 59. This insulating layer 63 permits the photocathode plate 23A to be cleaned by heat cleaning at a high temperature, in a stage before formation of an active layer 61 on an exposed region of the semiconductor electron emission layer 51 in the electron releasing portion 59. This makes it feasible to effectively clean the exposed region of the semiconductor electron emission layer 51 in the electron releasing portion 59 and to stabilize the physical properties of the exposed region. In consequence, a higher sensitive property can be stably achieved in the photocathode plate 23A and in the photomultiplier tube 1 using the photocathode plate 23A.Type: GrantFiled: October 21, 2004Date of Patent: February 13, 2007Assignee: Hamamatsu Photonics K.K.Inventors: Tomoko Mochizuki, Minoru Niigaki, Toru Hirohata, Kuniyoshi Mori
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Publication number: 20060038473Abstract: Provided are a photocathode plate capable of stably achieving a high sensitive property, and an electron tube using such a photocathode plate. In a photomultiplier tube 1, an insulating layer 63 is formed between a semiconductor electron emission layer 51 in a photocathode plate 23A, and a first electrode 65 electrically connected to an electron releasing portion 59. This insulating layer 63 permits the photocathode plate 23A to be cleaned by heat cleaning at a high temperature, in a stage before formation of an active layer 61 on an exposed region of the semiconductor electron emission layer 51 in the electron releasing portion 59. This makes it feasible to effectively clean the exposed region of the semiconductor electron emission layer 51 in the electron releasing portion 59 and to stabilize the physical properties of the exposed region. In consequence, a higher sensitive property can be stably achieved in the photocathode plate 23A and in the photomultiplier tube 1 using the photocathode plate 23A.Type: ApplicationFiled: October 21, 2004Publication date: February 23, 2006Inventors: Tomoko Mochizuki, Minoru Niigaki, Toru Hirohata, Kuniyoshi Mori
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Publication number: 20050168144Abstract: The invention relates to a photocathode having a structure that permits a decrease in the radiant sensitivity at low temperatures is suppressed so that the S/N ratio is improved. In the photocathode, a light absorbing layer is formed on the upper layer of a substrate. An electron emitting layer is formed on the upper layer of the light absorbing layer. A contact layer having a striped-shape is formed on the upper layer of the electron emitting layer. A surface electrode composed of metal is formed on the surface of the contact layer. The interval between bars in the contact layer is adjusted so as to become 0.2 ?m or more but 2 ?m or less.Type: ApplicationFiled: February 11, 2005Publication date: August 4, 2005Inventors: Toru Hirohata, Minoru Niigaki, Tomoko Mochizuki, Masami Yamada
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Patent number: 6903363Abstract: The invention relates to a photocathode having a structure that permits a decrease in the radiant sensitivity at low temperatures is suppressed so that the S/N ratio is improved. In the photocathode, a light absorbing layer is formed on the upper layer of a substrate. An electron emitting layer is formed on the upper layer of the light absorbing layer. A contact layer having a striped-shape is formed on the upper layer of the electron emitting layer. A surface electrode composed of metal is formed on the surface of the contact layer. The interval between bars in the contact layer is adjusted so as to become 0.2 ?m or more but 2 ?m or less.Type: GrantFiled: November 13, 2003Date of Patent: June 7, 2005Assignee: Hamamatsu Photonics K.K.Inventors: Toru Hirohata, Minoru Niigaki, Tomoko Mochizuki, Masami Yamada
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Publication number: 20040094755Abstract: The invention relates to a photocathode having a structure that permits a decrease in the radiant sensitivity at low temperatures is suppressed so that the S/N ratio is improved. In the photocathode, a light absorbing layer is formed on the upper layer of a substrate. An electron emitting layer is formed on the upper layer of the light absorbing layer. A contact layer having a striped-shape is formed on the upper layer of the electron emitting layer. A surface electrode composed of metal is formed on the surface of the contact layer. The interval between bars in the contact layer is adjusted so as to become 0.2 &mgr;m or more but 2 &mgr;m or less.Type: ApplicationFiled: November 13, 2003Publication date: May 20, 2004Applicant: HAMAMATSU PHOTONICS K.K.Inventors: Toru Hirohata, Minoru Niigaki, Tomoko Mochizuki, Masami Yamada
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Patent number: 6563264Abstract: This photocathode comprises: InP substrate 1; InAsx2P1−x2(0<x2<1) buffer layer 2; Inx1Ga1−x1As (1>x1>0.53) light-absorbing layer 3; InAsx3P1−x3 (0<x3<1) electron-emitting layer 4; InAsx3P1−x3 contact layer 5 formed on the electron-emitting layer 4; active layer 8 of an alkali metal or its oxide or fluoride formed on the exposed surface of electron-emitting layer 4; and electrodes 6 and 7.Type: GrantFiled: April 27, 2001Date of Patent: May 13, 2003Assignee: Hamamatsu Photonics K.K.Inventors: Minoru Niigaki, Toru Hirohata, Tomoko Mochizuki, Hirofumi Kan
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Publication number: 20020011787Abstract: This photocathode comprises: InP substrate 1; InAsx2P1−x2(0<x2<1) buffer layer 2; Inx1Ga1−x1As (1>x1>0.53) light-absorbing layer 3; InAsx3P1−x3 (0<x3<1) electron-emitting layer 4; InAsx3P1−x3 contact layer 5 formed on the electron-emitting layer 4; active layer 8 of an alkali metal or its oxide or fluoride formed on the exposed surface of electron-emitting layer 4; and electrodes 6 and 7.Type: ApplicationFiled: April 27, 2001Publication date: January 31, 2002Applicant: HAMAMATSU PHOTONICS K.K.Inventors: Minoru Niigaki, Toru Hirohata, Tomoko Mochizuki, Hirofumi Kan