Patents by Inventor Izumi Watanabe
Izumi Watanabe 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: 8779337Abstract: A thermal type flow sensor measures a flow rate of a fluid by means of a heat resistive element having a temperature dependency. The sensor is comprised of: plural heat resistive elements used for a flow rate measurement; and a driver circuit for controlling a current applied to these heat resistive elements to cause their heating. The driver circuit is configured to sense a resistance change of a lower-temperature side heat resistive element among the plural heat resistive elements and to control the current to be applied to the plural heat resistive elements in accordance with a sensed value of the lower-resistance's variation.Type: GrantFiled: July 5, 2012Date of Patent: July 15, 2014Assignee: Hitachi, Ltd.Inventors: Hiroshi Nakano, Masamichi Yamada, Masahiro Matsumoto, Izumi Watanabe
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Publication number: 20120279294Abstract: A thermal type flow sensor measures a flow rate of a fluid by means of a heat resistive element having a temperature dependency. The sensor is comprised of: plural heat resistive elements used for a flow rate measurement; and a driver circuit for controlling a current applied to these heat resistive elements to cause their heating. The driver circuit is configured to sense a resistance change of a lower-temperature side heat resistive element among the plural heat resistive elements and to control the current to be applied to the plural heat resistive elements in accordance with a sensed value of the lower-resistance's variation.Type: ApplicationFiled: July 5, 2012Publication date: November 8, 2012Inventors: Hiroshi NAKANO, Masamichi YAMADA, Masahiro MATSUMOTO, Izumi WATANABE
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Patent number: 8217320Abstract: A thermal type flow sensor measures a flow rate of a fluid by means of a heat resistive element having a temperature dependency. The sensor is comprised of: plural heat resistive elements used for a flow rate measurement; and a driver circuit for controlling a current applied to these heat resistive elements to cause their heating. The driver circuit is configured to sense a resistance change of a lower-temperature side heat resistive element among the plural heat resistive elements and to control the current to be applied to the plural heat resistive elements in accordance with a sensed value of the lower-resistance's variation.Type: GrantFiled: January 25, 2007Date of Patent: July 10, 2012Assignee: Hitachi, Ltd.Inventors: Hiroshi Nakano, Masamichi Yamada, Masahiro Matsumoto, Izumi Watanabe
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Patent number: 8203102Abstract: A thermal type flow sensor measures a flow rate of a fluid by means of a heat resistive element having a temperature dependency. The sensor is comprised of: plural heat resistive elements used for a flow rate measurement; and a driver circuit for controlling a current applied to these heat resistive elements to cause their heating. The driver circuit is configured to sense a resistance change of a lower-temperature side heat resistive element among the plural heat resistive elements and to control the current to be applied to the plural heat resistive elements in accordance with a sensed value of the lower-resistance's variation.Type: GrantFiled: March 15, 2010Date of Patent: June 19, 2012Assignee: Hitachi, Ltd.Inventors: Hiroshi Nakano, Masamichi Yamada, Masahiro Matsumoto, Izumi Watanabe
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Publication number: 20100170335Abstract: A thermal type flow sensor measures a flow rate of a fluid by means of a heat resistive element having a temperature dependency. The sensor is comprised of: plural heat resistive elements used for a flow rate measurement; and a driver circuit for controlling a current applied to these heat resistive elements to cause their heating. The driver circuit is configured to sense a resistance change of a lower-temperature side heat resistive element among the plural heat resistive elements and to control the current to be applied to the plural heat resistive elements in accordance with a sensed value of the lower-resistance's variation.Type: ApplicationFiled: March 15, 2010Publication date: July 8, 2010Inventors: Hiroshi Nakano, Masamichi Yamada, Masahiro Matsumoto, Izumi Watanabe
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Patent number: 7721599Abstract: Conventional thermal flow measurement devices lack consideration for automobiles in severe environments. A detection element of the thermal flow measurement device according to the present invention is structured by the provision of a planar substrate made of a material having good thermal conductivity, such as silicon or ceramic, with a thin-walled portion (diaphragm). On the surface of the thin-walled portion, the detection element comprises a heat element as a heater heated to a temperature being different to a predetermined extent from the temperature of the air flow to be measured, temperature-detecting resistors as temperature-detecting means on both sides of the heat element, wiring portions formed of electrical conductors that draw signal lines from the heat element and the temperature-detecting resistors and that have a melting point of 2000° C. or higher, and pads.Type: GrantFiled: February 20, 2006Date of Patent: May 25, 2010Assignee: Hitachi, Ltd.Inventors: Masahiro Matsumoto, Hiroshi Nakano, Masamichi Yamada, Keiji Hanzawa, Izumi Watanabe, Keiichi Nakada, Yasuhiro Kanamaru
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Patent number: 7685874Abstract: A thermal type flow sensor includes a base portion provided along the direction of a fluid flowing through a main passage, and a sensor element mounted on the base portion and having an exothermic resistor formed on a substrate for detecting the fluid flow rate. The base portion has a rectangular recessed portion in which the sensor element is fixed so that the surface of the detecting portion of the sensor element is positioned lower than an upper edge of the recessed portion. A wall portion of the measuring passage facing the sensor element is constricted. The exothermic resistor is disposed along the fluid passage and spaced away from the upstream side upper edge of the recessed portion and cannot be substantially affected by a fluid flow disturbance due to a step portion formed between the upper edge of the recessed portion and the detecting portion surface.Type: GrantFiled: July 17, 2007Date of Patent: March 30, 2010Assignee: Hitachi, Ltd.Inventors: Hiroshi Nakano, Masamichi Yamada, Masahiro Matsumoto, Izumi Watanabe
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Patent number: 7650784Abstract: A flow rate sensor has a problem that a resistance value of a heat generating resistor itself varies and sensor characteristics are changed during use of the sensor for a long term. Also, the temperature of the heat generating resistor must be adjusted on a circuit substrate with a resistance constituting one side of a fixed temperature difference control circuit, and this has been one of factors pushing up the production cost. All resistances used for fixed temperature difference control are formed on the same substrate as temperature sensitive resistors of the same material. This enables all the resistances for the fixed temperature difference control to be exposed to the same environmental conditions. Hence, even when the resistances change over time, the changes over time occur substantially at the same tendency. Since the resistances for the fixed temperature difference control change over time essentially at the same rate, a resulting output error is very small.Type: GrantFiled: June 16, 2008Date of Patent: January 26, 2010Assignees: Hitachi, Ltd., Hitachi Car Engineering Co., Ltd.Inventors: Izumi Watanabe, Junichi Horie, Keiichi Nakada, Kei Ueyama, Masamichi Yamada
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Patent number: 7631555Abstract: A thermal air flowmeter having excellent temperature characteristics and improved measurement accuracy. The thermal air flowmeter includes a temperature sensor disposed in a casing of the air flowmeter, a computing unit for correcting a flow rate detection voltage from a measuring element by using the temperature sensor, and a heating temperature control disposed in a temperature control circuit for performing temperature control of a heating resistor to vary a temperature rise of the heating resistor relative to an air temperature depending on the air temperature. Flow rate detection errors of the thermal air flowmeter caused by an overall temperature change and a temperature change on an intake passage wall surface can be corrected simultaneously and a thermal air flowmeter having superior measurement accuracy can be realized.Type: GrantFiled: November 20, 2003Date of Patent: December 15, 2009Assignees: Hitachi, Ltd., Hitachi Car Engineering Co., Ltd.Inventors: Hiroshi Nakano, Masamichi Yamada, Masahiro Matsumoto, Izumi Watanabe, Keiji Hanzawa, Keiichi Nakada
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Patent number: 7624633Abstract: A thermal-type fluid flow sensor comprises a heating resistor formed on a thin film of a substrate, and plural thermal sensitive resistors configuring a bridge circuit. The thermal sensitive resistors are disposed on the thin film of the substrate so as to be located on an adjacent upstream side and an adjacent downstream side of the heating resistor in a stream direction of fluid to be measured. Resistor traces for the thermal sensitive resistors are formed so that the respective thermal sensitive resistors exhibit substantially equal changes in resistance with each other to distortion caused in the thin film.Type: GrantFiled: September 12, 2007Date of Patent: December 1, 2009Assignees: Hitachi, Ltd., Hitachi Car Engineering Co., Ltd.Inventors: Keiichi Nakada, Junichi Horie, Hiroshi Nakano, Izumi Watanabe
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Patent number: 7565255Abstract: In regard to an output of an intake flow meter for an internal combustion engine, a pulsation error can be reduced and dispersion in correction at the time of correction of response delay (a recovering of response delay) is reduced. A digital device is used for pre-processing of a control unit for inputting a flow rate measuring signal. An output voltage of the flow sensor is converted into a digital value, the digital value is converted into a flow rate and adds a response delay. The control unit detects a degree of response delay in reference to dispersion in a clock signal so as to perform response delay recovering and reduce dispersion of the response delay.Type: GrantFiled: September 30, 2004Date of Patent: July 21, 2009Assignees: Hitachi, Ltd., Hitachi Car Engineering Co., Ltd.Inventors: Atsushi Kanke, Izumi Watanabe, Keiji Hanzawa
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Patent number: 7559237Abstract: The present invention provides an air flow measuring device comprising a housing with a sub-passage having a inlet and a outlet for air flow formed in the housing, the sub-passage further having a predefined curvature with a maximum downstream point and a flow measuring element located in the sub-passage at a position at least further downstream from the point.Type: GrantFiled: April 29, 2008Date of Patent: July 14, 2009Assignees: Hitachi Ltd., Hitachi Car Engineering Co., Ltd.Inventors: Hiromu Kikawa, Izumi Watanabe, Shinya Igarashi, Keiichi Nakada, Kei Ueyama
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Patent number: 7555944Abstract: A highly accurate physical quantity sensor which can ensure reliability in strength and reduce resistance changes caused by stresses. Assuming, with respect to stress ? imposed on a substrate in a predetermined direction (e.g., direction in which maximum stress is imposed), a parallel direction to be a horizontal direction and a perpendicular direction to be a vertical direction, each of resistors of the sensor has a horizontal resistance component Rl and a vertical resistance component Rt.Type: GrantFiled: February 15, 2006Date of Patent: July 7, 2009Assignee: Hitachi, Ltd.Inventors: Hiroshi Nakano, Masahiro Matsumoto, Masamichi Yamada, Keiichi Nakada, Izumi Watanabe
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Publication number: 20090000372Abstract: Conventional thermal flow measurement devices lack consideration for automobiles in severe environments. A detection element of the thermal flow measurement device according to the present invention is structured by the provision of a planar substrate made of a material having good thermal conductivity, such as silicon or ceramic, with a thin-walled portion (diaphragm). On the surface of the thin-walled portion, the detection element comprises a heat element as a heater heated to a temperature being different to a predetermined extent from the temperature of the air flow to be measured, temperature-detecting resistors as temperature-detecting means on both sides of the heat element, wiring portions formed of electrical conductors that draw signal lines from the heat element and the temperature-detecting resistors and that have a melting point of 2000° C. or higher, and pads.Type: ApplicationFiled: February 20, 2006Publication date: January 1, 2009Inventors: Masahiro Matsumoto, Hiroshi Nakano, Masamichi Yamada, Keiji Hanzawa, Izumi Watanabe, Keiichi Nakada, Yasuhiro Kanamaru
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Patent number: 7437927Abstract: The invention provides a thermal type flow meter which has a high reliability and a low cost. In a thermal type flow meter provided with a flow rate detecting element in which at least a heat generating resistor and a lead electrode are formed on a surface of a tabular substrate, and a support body in which a concave portion accommodating the flow rate detecting element is formed on a surface, and in which the flow rate detecting element is firmly fixed and accommodated by an adhesive agent in a back surface of the tabular substrate and a part of a bottom surface of the concave portion, an approximately straight discharge groove which is deeper than a bottom surface of the concave portion and passes through both end surfaces in upward and downward sides of the concave portion is formed from the upstream side of the support body concave portion to the downstream side, between the cavity of the tabular substrate and the back surface region of the tabular substrate in which the lead electrode is formed.Type: GrantFiled: August 8, 2007Date of Patent: October 21, 2008Assignee: Hitachi, Ltd.Inventors: Masamichi Yamada, Masahiro Matsumoto, Hiroshi Nakano, Akio Yasukawa, Izumi Watanabe
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Publication number: 20080250855Abstract: A thermal-type fluid flow sensor comprises a heating resistor formed on a thin film of a substrate, and plural thermal sensitive resistors configuring a bridge circuit. The thermal sensitive resistors are disposed on the thin film of the substrate so as to be located on an adjacent upstream side and an adjacent downstream side of the heating resistor in a stream direction of fluid to be measured. Resistor traces for the thermal sensitive resistors are formed so that the respective thermal sensitive resistors exhibit substantially equal changes in resistance with each other to distortion caused in the thin film.Type: ApplicationFiled: September 12, 2007Publication date: October 16, 2008Applicants: HITACHI, LTD., HITACHI CAR ENGINEERING CO., LTD.Inventors: Keiichi NAKADA, Junichi HORIE, Hiroshi NAKANO, Izumi WATANABE
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Publication number: 20080250856Abstract: A flow rate sensor has a problem that a resistance value of a heat generating resistor itself varies and sensor characteristics are changed during use of the sensor for a long term. Also, the temperature of the heat generating resistor must be adjusted on a circuit substrate with a resistance constituting one side of a fixed temperature difference control circuit, and this has been one of factors pushing up the production cost. All resistances used for fixed temperature difference control are formed on the same substrate as temperature sensitive resistors of the same material. This enables all the resistances for the fixed temperature difference control to be exposed to the same environmental conditions. Hence, even when the resistances change over time, the changes over time occur substantially at the same tendency. Since the resistances for the fixed temperature difference control change over time essentially at the same rate, a resulting output error is very small.Type: ApplicationFiled: June 16, 2008Publication date: October 16, 2008Inventors: Izumi WATANABE, Junichi Horie, Keiichi Nakada, Kei Ueyama, Masamichi Yamada
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Publication number: 20080202230Abstract: The present invention provides an air flow measuring device comprising a housing with a sub-passage having a inlet and a outlet for air flow formed in the housing, the sub-passage further having a predefined curvature with a maximum downstream point and a flow measuring element located in the sub-passage at a position at least further downstream from the point.Type: ApplicationFiled: April 29, 2008Publication date: August 28, 2008Inventors: Hiromu Kikawa, Izumi Watanabe, Shinya Igarashi, Keiichi Nakada, Kei Ueyama
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Patent number: 7409859Abstract: A thermal type flow measuring apparatus includes a heating resistor provided in a thin part of a substrate and a bridge circuit for driving the heating resistor to have a preset heating temperature, wherein resistor elements on sides forming the bridge circuit are temperature sensitive resistors, a part or whole of at least one of the temperature sensitive resistors is placed in the thin part and near the heating resistor so that the temperature sensitive resistor is influenced by a heat of the heating resistor, and the preset heating temperature is increased as the flow of fluid is increased. This configuration introduces flow dependency into the heating temperature of the heating resistor.Type: GrantFiled: July 6, 2006Date of Patent: August 12, 2008Assignee: Hitachi, Ltd.Inventors: Izumi Watanabe, Junichi Horie, Keiichi Nakada
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Patent number: RE42529Abstract: A thermal type flow rate measuring device can certainly prevent adhesion of water droplet onto a sensor element and thus achieve high reliability. The thermal type flow rate measuring device includes an auxiliary passage defined within a main passage for introducing a part of fluid flowing through the main passage, a sensor disposed within the auxiliary passage for detecting flow rate of the fluid and capturing means formed on an inner periphery of the auxiliary passage for capturing liquid contained in the fluid and transferring the captured liquid.Type: GrantFiled: June 3, 2005Date of Patent: July 12, 2011Assignees: Hitachi, Ltd., Hitachi Car Engineering Co., Ltd.Inventors: Izumi Watanabe, Junichi Horie, Keiichi Nakada, Kei Ueyama