Patents by Inventor Takashi Hatai
Takashi Hatai 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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Publication number: 20110163686Abstract: A lighting device comprising a hermetically sealed vessel having a light transmissive property, a gas filled in the hermetically sealed vessel and configured to emit a first light having wavelength when excited by electron, the wavelength of the first light has a range from vacuum ultraviolet to visual light, an electron source disposed within the hermetically sealed vessel, the electron source configured to emit the electron when an operation voltage is applied, anode electrode disposed within the hermetically sealed vessel, a phosphor configured to emit the second light when excited by the first light. The electron source is configured to emit the electron having energy distribution when the electron source receives the emission voltage. The energy distribution having a peak energy. The peak energy is higher than an excitation energy of the gas. The peak energy is lower than an ionization energy of the gas.Type: ApplicationFiled: July 8, 2009Publication date: July 7, 2011Inventors: Tsutomu Ichihara, Takashi Hatai
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Patent number: 7378656Abstract: An infrared radiation element A heat insulating layer having sufficiently smaller thermal conductivity than a semiconductor substrate, is formed on a surface in the thickness direction of the semiconductor substrate. A heating layer, which is in the form of a lamina (plane) and has larger thermal conductivity and larger electrical conductivity than the heat insulating layer, is formed on the heat insulating layer. A pair of pads 4 for energization are formed on the heating layer. The semiconductor substrate is made of a silicon substrate. The heat insulating layer and the heating layer are formed by porous silicon layers having different porosities from each other, and the heating layer has smaller porosity than the heat insulating layer. By using the infrared radiation element as an infrared radiation source of a gas sensor, it becomes possible to extend a life of the infrared radiation source.Type: GrantFiled: October 27, 2004Date of Patent: May 27, 2008Assignee: Matsushita Electric Works, Ltd.Inventors: Tsutomu Ichihara, Chousei Hamada, Koshi Akedo, Hiroaki Kitamura, Hiroshi Fukshima, Takuya Komoda, Takashi Hatai
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Publication number: 20070090293Abstract: In the infrared radiation element (A), a heat insulating layer 2, which has sufficiently smaller thermal conductivity than a semiconductor substrate 1, is formed on a surface in the thickness direction of the semiconductor substrate 1, and a heating layer 3, which is in the form of a lamina (plane) and has larger thermal conductivity and larger electrical conductivity than the heat insulating layer 2, is formed on the heat insulating layer 2, and a pair of pads 4 for energization are formed on the heating layer 3. The semiconductor substrate 1 is made of a silicon substrate. The heat insulating layer 2 and the heating layer 3 are formed by porous silicon layers having different porosities from each other, and the heating layer 3 has smaller porosity than the heat insulating layer 2. By using the infrared radiation element (A) as an infrared radiation source of a gas sensor, it becomes possible to extend a life of the infrared radiation source.Type: ApplicationFiled: October 27, 2004Publication date: April 26, 2007Inventors: Tsutomu Ichihara, Chousei Hamada, Koshi Akedo, Hiroaki Kitamura, Hiroshi Fukshima, Takuya Komoda, Takashi Hatai
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Patent number: 6844664Abstract: In a field emission-type electron source (10), a strong field drift layer (6) and a surface electrode (7) consisting of a gold thin film are provided on an n-type silicon substrate (1). An ohmic electrode (2) is provided on the back surface of the n-type silicon substrate (1). A direct current voltage is applied so that the surface electrode (7) becomes positive in potential relevant to the ohmic electrode (2). In this manner, electrons injected from the ohmic electrode (2) into the strong field drift layer (6) via the n-type silicon substrate (6) drift in the strong field drift layer (6), and is emitted to the outside via the surface electrode (7).Type: GrantFiled: April 24, 2002Date of Patent: January 18, 2005Assignee: Matsushita Electric Works, Ltd.Inventors: Takuya Komoda, Koichi Aizawa, Yoshiaki Honda, Tsutomu Ichihara, Yoshifumi Watabe, Takashi Hatai, Toru Baba, Yoshiyuki Takegawa
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Patent number: 6815315Abstract: Disclosed is a method for the electrochemical oxidation of a semiconductor layer. In an electrochemical oxidation treatment for the production process of an electron source 10 (field-emission type electron source) as one of electronic devices, a control section 37 determines a voltage increment due to the resistance of an electrolytic solution B in advance, based on a detected voltage from a resistance detect section 35. Then, the control section 37 controls a current source to supply a constant current so as to initiate an oxidation treatment for a semiconductor layer formed on an object 30. The control section 37 corrects a detected voltage from a voltage detect section 36 by subtracting the voltage increment therefrom. When the corrected voltage reaches a given upper voltage value, the control section 37 is operable to discontinue the output of the current source 32 and terminate the oxidation treatment.Type: GrantFiled: January 8, 2004Date of Patent: November 9, 2004Assignee: Matsushita Electric Works, Ltd.Inventors: Yoshifumi Watabe, Koichi Aizawa, Takuya Komoda, Takashi Hatai, Yoshiaki Honda
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Patent number: 6794805Abstract: An array of field emission electron sources and a method of preparing the array which discharges electrons from desired regions of a surface electrode of field emission electron sources. The field emission electron source 10 comprises an electrically conductive substrate of p-type silicon substrate 1; n-type regions 8 of stripes of diffusion layers on one of principal surfaces of the p-type silicon substrate, strong electric field drift layers 6 formed on the n-type regions 8 which is made of oxidized porous poly-silicon for drifting electrons injected from the n-type region 8; poly-silicon layers 3 between the strong field drift layers 6; surface electrodes 7 of the stripes of thin conductive film formed in a manner to cross over the stripes of the strong field drift layer 6 and the poly-silicon layers 3.Type: GrantFiled: August 25, 1999Date of Patent: September 21, 2004Assignee: Matsushita Electric Works, Ltd.Inventors: Takashi Hatai, Takuya Komoda, Yoshiaki Honda, Koichi Aizawa, Yoshifumi Watabe, Tsutomu Ichihara, Yukihiro Kondo, Naomasa Oka, Nobuyoshi Koshida
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Publication number: 20040180516Abstract: Disclosed is a method for the electrochemical oxidation of a semiconductor layer. In an electrochemical oxidation treatment for the production process of an electron source 10 (field-emission type electron source) as one of electronic devices, a control section 37 determines a voltage increment due to the resistance of an electrolytic solution B in advance, based on a detected voltage from a resistance detect section 35. Then, the control section 37 controls a current source to supply a constant current so as to initiate an oxidation treatment for a semiconductor layer formed on an object 30. The control section 37 corrects a detected voltage from a voltage detect section 36 by subtracting the voltage increment therefrom. When the corrected voltage reaches a given upper voltage value, the control section 37 is operable to discontinue the output of the current source 32 and terminate the oxidation treatment.Type: ApplicationFiled: January 8, 2004Publication date: September 16, 2004Inventors: Yoshifumi Watabe, Koichi Aizawa, Takuya Komoda, Takashi Hatai, Yoshiaki Honda
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Patent number: 6784621Abstract: An electron source (10) has an electron source element (10a) including a lower electrode (12), a drift layer (6) and a surface electrode (7). The drift layer (6) is interposed between the lower electrode (12) and the surface electrode (7). When a certain voltage is applied between the surface electrode (7) and the lower electrode (12) such that the surface electrode (7) has a higher potential than that of the lower electrode (12), a resultingly induced electric field allows electrons to pass through the drift layer (6) and then the electrons are emitted through the surface electrode (7). When a forward-bias voltage is applied between the surface electrode (7) and the lower electrode (12), a reverse-bias voltage is applied after the forward-bias voltage has been applied to release out of the drift layer (6) an electron captured by a trap (9) in the drift layer (6).Type: GrantFiled: October 28, 2002Date of Patent: August 31, 2004Assignee: Matsushita Electric Works, Ltd.Inventors: Takuya Komoda, Tsutomu Ichihara, Koichi Aizawa, Yoshiaki Honda, Yoshifumi Watabe, Takashi Hatai, Yoshiyuki Takegawa, Toru Baba
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Patent number: 6765342Abstract: A field emission-type electron source 10 includes an insulative substrate 11 in the form of a glass substrate having an electroconductive layer 8 formed thereon. A strong electrical field drift layer 6 in the form of an oxidized porous polycrystalline silicon layer is formed over the electroconductive layer 8. This electroconductive layer 8 includes a lower electroconductive film 8a, made of copper and formed on the insulative substrate 11, and an upper electroconductive film 8b made of aluminum and formed over the electroconductive film 8a. The strong electrical field drift layer 6 is formed by forming a polycrystalline silicon layer on the electroconductive layer 8, rendering the polycrystalline silicon layer to be porous and finally oxidizing it. The upper electroconductive film 8b has a property that reacts easily with silicon and, therefore, formation of an amorphous layer which would occur during formation of the polycrystalline silicon layer can be suppressed.Type: GrantFiled: October 17, 2000Date of Patent: July 20, 2004Assignee: Matsushita Electric Work, Ltd.Inventors: Yoshiaki Honda, Tsutomu Ichihara, Takuya Komoda, Koichi Aizawa, Yoshifumi Watabe, Takashi Hatai
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Patent number: 6753196Abstract: An electron source 10 has an n-type silicon substrate 1, a drift layer 6 formed on one surface of the substrate 1, and a surface electrode 7 formed on the drift layer 6. A voltage is applied so that the surface electrode 7 becomes positive in polarity relevant to the substrate 1, whereby electrons injected from the substrate 1 into the drift layer 6 drift within the drift layer 6, and are emitted through the surface electrode 7. In a process for manufacturing this electron source 10, when the drift layer 6 is formed, a porous semiconductor layer containing a semiconductor nanocrystal is formed in accordance with anodic oxidation. Then, an insulating film is formed on the surface of each semiconductor nanocrystal. Anodic oxidation is carried out while emitting light that essentially contains a wavelength in a visible light region relevant to the semiconductor layer.Type: GrantFiled: June 25, 2002Date of Patent: June 22, 2004Assignee: Matsushita Electric Works, Ltd.Inventors: Takuya Komoda, Tsutomu Ichihara, Koichi Aizawa, Yoshiaki Honda, Yoshifumi Watabe, Takashi Hatai, Toru Baba
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Patent number: 6720717Abstract: A lower electrode (2) and surface electrode (7) composed of a layer-structured conductive carbide layer is formed on one principal surface side of the substrate (1) composed of an insulative substrate such as a glass or ceramic substrate. A non-doped polycrystalline silicon layer (3) is formed on the lower electrode (2). An electron transit layer (6) composed of an oxidized porous polycrystalline silicon is formed on the polycrystalline silicon layer (3). The electron transit layer (6) is composed of a composite nanocrystal layer including polycrystalline silicon and many nanocrystalline silicons residing adjacent to a grain boundary of the polycrystalline silicon. When voltage is applied between the lower electrode (2) and the surface electrode (7) such that the surface electrode (7) has a higher potential, electrons are injected from the lower electrode (2) toward the surface electrode (7), and emitted through the surface electrode (7) through the electron transit layer (6).Type: GrantFiled: September 24, 2002Date of Patent: April 13, 2004Assignee: Matsushita Electric Works, Ltd.Inventors: Takuya Komoda, Yoshiyuki Takegawa, Koichi Aizawa, Takashi Hatai, Tsutomu Ichihara, Yoshiaki Honda, Yoshifumi Watabe, Toru Baba
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Patent number: 6707061Abstract: In a field emission-type electron source (10), lower electrodes (8) made of an electroconductive layer, a strong field drift layer (6) including drift portions (6a) made of an oxidized or nitrided porous semiconductor, and surface electrodes (7) made of a metal layer are provided on an upper side of a dielectric substrate (11) made of glass. When voltage is applied to cause the surface electrodes (7) to be anodic with respect to the lower electrodes (8), electrons injected from the lower electrodes (8) to the strong field drift layer (6) are led to drift through the strong field drift layer (6) and are emitted outside through the surface electrodes (7). A pn-junction semiconductor layer composed of an n-layer (21) and a p-layer (22) is provided between the lower electrode (8) and the strong field drift layer (6) to prevent a leakage current from flowing to the surface electrode (7) from the lower electrode (8), thereby reducing amount of power consumption.Type: GrantFiled: July 22, 2002Date of Patent: March 16, 2004Assignee: Matsushita Electric Works, Ltd.Inventors: Takuya Komoda, Yoshiaki Honda, Koichi Aizawa, Tsutomu Ichihara, Yoshifumi Watabe, Takashi Hatai, Toru Baba
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Patent number: 6583578Abstract: An electron source (10) is provided with an n-type silicon substrate (1) as a conductive substrate, a drift layer (6) composed of oxidized porous polycrystalline silicon which is formed on the main surface of the silicon substrate (1), and a surface electrode (7) as a conductive thin film formed on the drift layer (6). The process for, forming the surface electrode (7) includes the steps of forming a first layer composed of Cr on the drift layer (6), forming a second layer composed of Au on the first layer, and alloying the two layers. The surface electrode (7) has higher adhesion for the drift layer 6 and/or stability for the lapse of time. In addition, the surface electrode (7) has lower density of states in an energy region near energy of emitted electrons, in comparison with the simple substance of Cr. In the surface electrode (7), scattering of the electrons is less so that electron emitting efficiency is higher.Type: GrantFiled: October 17, 2000Date of Patent: June 24, 2003Assignee: Matsushita Electric Works, Ltd.Inventors: Tsutomu Ichihara, Takuya Komoda, Koichi Aizawa, Yoshiaki Honda, Yoshifumi Watabe, Takashi Hatai
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Publication number: 20030102793Abstract: In a field emission-type electron source (10), a strong field drift layer (6) and a surface electrode (7) consisting of a gold thin film are provided on an n-type silicon substrate (1). An ohmic electrode (2) is provided on the back surface of the n-type silicon substrate (1). A direct current voltage is applied so that the surface electrode (7) becomes positive in potential relevant to the ohmic electrode (2). In this manner, electrons injected from the ohmic electrode (2) into the strong field drift layer (6) via the n-type silicon substrate (6) drift in the strong field drift layer (6), and is emitted to the outside via the surface electrode (7).Type: ApplicationFiled: November 5, 2002Publication date: June 5, 2003Inventors: Takuya Komoda, Koichi Aizawa, Yoshiaki Honda, Tsutomu Ichihara, Yoshifumi Watabe, Takashi Hatai, Toru Baba, Yoshiyuki Takegawa
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Publication number: 20030090211Abstract: An electron source (10) has an electron source element (10a) including a lower electrode (12), a drift layer (6) and a surface electrode (7). The drift layer (6) is interposed between the lower electrode (12) and the surface electrode (7). When a certain voltage is applied between the surface electrode (7) and the lower electrode (12) such that the surface electrode (7) has a higher potential than that of the lower electrode (12), a resultingly induced electric field allows electrons to pass through the drift layer (6) and then the electrons are emitted through the surface electrode (7). When a forward-bias voltage is applied between the surface electrode (7) and the lower electrode (12), a reverse-bias voltage is applied after the forward-bias voltage has been applied to release out of the drift layer (6) an electron captured by a trap (9) in the drift layer (6).Type: ApplicationFiled: October 28, 2002Publication date: May 15, 2003Applicant: MATSUSHITA ELECTRIC WORKS, LTD.Inventors: Takuya Komoda, Tsutomu Ichihara, Koichi Aizawa, Yoshiaki Honda, Yoshifumi Watabe, Takashi Hatai, Yoshiyuki Takegawa, Toru Baba
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Publication number: 20030076023Abstract: A lower electrode (2) and surface electrode (7) composed of a layer-structured conductive carbide layer is formed on one principal surface side of the substrate (1) composed of an insulative substrate such as a glass or ceramic substrate. A non-doped polycrystalline silicon layer (3) is formed on the lower electrode (2), An electron transit layer (6) composed of an oxidized porous polycrystalline silicon is formed on the polycrystalline silicon layer (3). The electron transit layer (6) is composed of a composite nanocrystal layer including polycrystalline silicon and many nanocrystalline silicons residing adjacent to a grain boundary of the polycrystalline silicon. When voltage is applied between the lower electrode (2) and the surface electrode (7) such that the surface electrode (7) has a higher potential, electrons are injected from the lower electrode (2) toward the surface electrode (7), and emitted through the surface electrode (7) through the electron transit layer (6).Type: ApplicationFiled: September 24, 2002Publication date: April 24, 2003Applicant: Matsushita Electric Works, Ltd.Inventors: Takuya Komoda, Yoshiyuki Takegawa, Koichi Aizawa, Takashi Hatai, Tsutomu Ichihara, Yoshiaki Honda, Yoshifumi Watabe, Toru Baba
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Publication number: 20030020059Abstract: In a field emission-type electron source (10), lower electrodes (8) made of an electroconductive layer, a strong field drift layer (6) including drift portions (6a) made of an oxidized or nitrided porous semiconductor, and surface electrodes (7) made of a metal layer are provided on an upper side of a dielectric substrate (11) made of glass. When voltage is applied to cause the surface electrodes (7) to be anodic with respect to the lower electrodes (8), electrons injected from the lower electrodes (8) to the strong field drift layer (6) are led to drift through the strong field drift layer (6) and are emitted outside through the surface electrodes (7). A pn-junction semiconductor layer composed of an n-layer (21) and a p-layer (22) is provided between the lower electrode (8) and the strong field drift layer (6) to prevent a leakage current from flowing to the surface electrode (7) from the lower electrode (8), thereby reducing amount of power consumption.Type: ApplicationFiled: July 22, 2002Publication date: January 30, 2003Inventors: Takuya Komoda, Yoshiaki Honda, Koichi Aizawa, Tsutomu Ichihara, Yoshifumi Watabe, Takashi Hatai, Toru Baba
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Publication number: 20030013215Abstract: An electron source 10 has an n-type silicon substrate 1, a drift layer 6 formed on one surface of the substrate 1, and a surface electrode 7 formed on the drift layer 6. A voltage is applied so that the surface electrode 7 becomes positive in polarity relevant to the substrate 1, whereby electrons injected from the substrate 1 into the drift layer 6 drift within the drift layer 6, and are emitted through the surface electrode 7. In a process for manufacturing this electron source 10, when the drift layer 6 is formed, a porous semiconductor layer containing a semiconductor nanocrystal is formed in accordance with anodic oxidation. Then, an insulating film is formed on the surface of each semiconductor nanocrystal. Anodic oxidation is carried out while emitting light that essentially contains a wavelength in a visible light region relevant to the semiconductor layer.Type: ApplicationFiled: June 25, 2002Publication date: January 16, 2003Applicant: Matsushita Electric Works, Ltd.Inventors: Takuya Komoda, Tsutomu Ichihara, Koichi Aizawa, Yoshiaki Honda, Yoshifumi Watabe, Takashi Hatai, Toru Baba
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Patent number: 6498426Abstract: A field emission-type electron source (10) is provided with a conductive substrate (1), a semiconductor layer formed on a surface of the conductive substrate (1), at least a part of the semiconductor layer being made porous, and a conductive thin film (7) formed on the semiconductor layer. Electrons injected into the conductive substrate (1) are emitted from the conductive thin film (7) through the semiconductor layer by applying a voltage between the conductive thin film (7) and the conductive substrate (1) in such a manner that the conductive thin film (7) acts as a positive electrode against the conductive substrate (1). The semiconductor layer includes a porous semiconductor layer (6) in which columnar structures (21) and porous structures (25) composed of fine semiconductor crystals of nanometer scale coexist, a surface of each of the structures being covered with an insulating film (22,24).Type: GrantFiled: April 21, 2000Date of Patent: December 24, 2002Assignee: Matsushita Electric Works, Ltd.Inventors: Yoshifumi Watabe, Yukihiro Kondo, Koichi Aizawa, Takuya Komoda, Yoshiaki Honda, Takashi Hatai, Tsutomu Ichihara, Nobuyoshi Koshida
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Patent number: 6285118Abstract: A field emission type electron source 10 is provided with an n-type silicon substrate 1, a strong field drift layer 6 formed on the n-type silicon substrate 1 directly or inserting a polycrystalline silicon layer 3 therebetween, and an electrically conductive thin film 7, which is a thin gold film, formed on the strong field drift layer 6. Further, an ohmic electrode 2 is provided on the back surface of the n-type silicon substrate 1. Hereupon, electrons, which are injected from the n-type silicon substrate 1 into the strong field drift layer 6, drift in the strong field drift layer 6 toward the surface of the layer, and then pass through the electrically conductive thin film 7 to be emitted outward. The strong field drift layer 6 is formed by making the polycrystalline silicon 3 formed on the n-type silicon substrate 1 porous by means of an anodic oxidation, and further oxidizing it using dilute nitric acid or the like.Type: GrantFiled: November 15, 1999Date of Patent: September 4, 2001Assignee: Matsushita Electric Works, Ltd.Inventors: Takashi Hatai, Takuya Komoda, Yoshiaki Honda, Koichi Aizawa, Yoshifumi Watabe, Tsutomu Ichihara, Yukihiro Kondo, Nobuyoshi Koshida