Patents by Inventor Katsumi Kakuta
Katsumi Kakuta 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: 20130253864Abstract: The magnetic-field direction measuring apparatus includes a substantially rectangular rotation angle measuring chip, and a first magnetic field sensor and a second magnetic field sensor disposed substantially on a circumference centered around a predetermined point on a surface of the rotation angle measuring chip serving as a circle center point, the first magnetic field sensor detecting a magnetic component in a first direction, the second magnetic field sensor detecting a magnetic component in a second direction different from the first direction. The first magnetic field sensor and the second magnetic field sensor are positioned line-symmetrically with respect to a straight line on the surface of the substrate which is parallel to a longitudinal direction of the rotation angle measuring chip or a transverse direction of the rotation angle measuring chip and which serves as an axis of symmetry.Type: ApplicationFiled: March 18, 2013Publication date: September 26, 2013Applicant: ASAHI KASEI MICRODEVICES CORPORATIONInventors: Taisuke Fujita, Yoshihiko Watanabe, Katsumi Kakuta
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Patent number: 8169215Abstract: The present invention relates to a magnetic sensor with which magnetic characteristics are made extremely stable by consideration of an area of contact of a base layer of a magnetic substance and a semiconductor substrate. On a semiconductor substrate (111) a plurality of Hall elements (112a, 112b) are embedded so as to be coplanar to a top surface of the semiconductor substrate while being mutually spaced apart by a predetermined distance, and above the Hall elements and the semiconductor substrate, a base layer (114), having coefficient of thermal expansion differing from that of the Hall elements and partially covers a region of each Hall elements, is formed via a protective layer (113), and a magnetic flux concentrator (115), having an area larger than the base layer and with magnetic amplification, is formed on the base layer. An area of contact of the base layer of the magnetic substance and the semiconductor substrate is made small to lessen the generation of an offset voltage.Type: GrantFiled: March 28, 2007Date of Patent: May 1, 2012Assignee: Asahi Kasei EMD CorporationInventors: Makoto Kataoka, Katsumi Kakuta, Yo Yamagata, Yuichi Kanayama
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Patent number: 8085035Abstract: A Hall element is provided which has a high sensitivity and contributes to an improvement in S/N ratio per current by using a low-concentration n-well within a suitable range. The Hall element includes a p-type semiconductor substrate layer of p-type silicon, and an n-type impurity region located in a surface of the p-type semiconductor substrate layer, the n-type impurity region functioning as a magnetic sensing part. A p-type impurity region is located in a surface of the n-type impurity region, and n-type regions are located laterally of the p-type impurity region. A p-type substrate region having a resistivity equal to that of the p-type semiconductor substrate layer is located to extend around the n-type impurity region. An impurity concentration N in the n-type impurity region functioning as the magnetic sensing part is preferably from 1×1016 to 3×1016(atoms/cm3) and a distribution depth of the impurity concentration is preferably from 3.0 ?m to 5.0 ?m.Type: GrantFiled: March 30, 2007Date of Patent: December 27, 2011Assignee: Asahi Kasei EMD CorporationInventors: Takayuki Namai, Katsumi Kakuta
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Patent number: 7818138Abstract: The present invention relates to a position detecting device capable of canceling an error due to looseness in a vertical direction and of eliminating variation in temperature characteristics by calculating a ratio between output voltages of a plurality of Hall elements. Assuming that the Hall voltage Vhe1 of a Hall element becomes A·K·Bhe1 (A is the amplification factor of a preamplifier, K is a constant, and Bhe1 is the magnetic flux density the Hall element receives), then a PI regulator automatically adjusts the bias point of the PI output by feedback control in such a manner that A·K·Bhe1+Vref=AGND (=0) holds. The Hall voltage Vhe2 of the Hall element after amplification becomes A·K·Bhe2. Since K=?Vref/A·Bhe1, the Hall voltage Vhe2 of the Hall element is given by ?Vref·Bhe2/Bhe1.Type: GrantFiled: April 26, 2007Date of Patent: October 19, 2010Assignee: Asahi Kasei EMD CorporationInventors: Takashi Yoshida, Masaru Suzuki, Katsumi Kakuta
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Publication number: 20100164483Abstract: A Hall element is provided which has a high sensitivity and contributes to an improvement in S/N ratio per current by using a low-concentration n-well within a suitable range. The Hall element includes a p-type semiconductor substrate layer 21 of p-type silicon, and an n-type impurity region 22 located in a surface of the p-type semiconductor substrate layer 21, the n-type impurity region 22 functioning as a magnetic sensing part 26. A p-type impurity region 23 is located in a surface of the n-type impurity region 22, and n-type regions 24 are located laterally of the p-type impurity region 23. A p-type substrate region 21a having a resistivity equal to that of the p-type semiconductor substrate layer 21 is located to extend around the n-type impurity region 22. An impurity concentration N in the n-type impurity region 22 functioning as the magnetic sensing part 26 is preferably from 1×1016 to 3×1016 (atoms/cm3), and a distribution depth D of the impurity concentration is preferably from 3.0 ?m to 5.0 ?m.Type: ApplicationFiled: March 30, 2007Publication date: July 1, 2010Inventors: Takayuki Namai, Katsumi Kakuta
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Publication number: 20090309590Abstract: The present invention relates to a magnetic sensor with which magnetic characteristics are made extremely stable by consideration of an area of contact of a base layer of a magnetic substance and a semiconductor substrate. On a semiconductor substrate a plurality of Hall elements are embedded so as to be coplanar to a top surface of the semiconductor substrate while being mutually spaced apart by a predetermined distance, and above the Hall elements and the semiconductor substrate, a base layer, having a coefficient of thermal expansion differing from that of the Hall elements and partially covers a region of each Hall element, is formed via a protective layer, and a magnetic flux concentrator, having an area larger than the base layer and with magnetic amplification, is formed on the base layer.Type: ApplicationFiled: March 28, 2007Publication date: December 17, 2009Inventors: Makoto Kataoka, Katsumi Kakuta, Yo Yamagata, Yuichi Kanayama
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Publication number: 20090177436Abstract: The present invention relates to a position detecting device capable of canceling an error due to looseness in a vertical direction and of eliminating variation in temperature characteristics by calculating a ratio between output voltages of a plurality of Hall elements. Assuming that the Hall voltage Vhe1 of a Hall element becomes A·K·Bhe1 (A is the amplification factor of a preamplifier, K is a constant, and Bhe1 is the magnetic flux density the Hall element receives), then a PI regulator automatically adjusts the bias point of the PI output by feedback control in such a manner that A·K·Bhe1+Vref=AGND (=0) holds. The Hall voltage Vhe2 of the Hall element after amplification becomes A·K·Bhe2. Since K=?Vref/A·Bhe1, the Hall voltage Vhe2 of the Hall element is given by ?Vref·Bhe2/Bhe1.Type: ApplicationFiled: April 26, 2007Publication date: July 9, 2009Inventors: Takashi Yoshida, Masaru Suzuki, Katsumi Kakuta
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Patent number: 6969988Abstract: An angle detection apparatus for detecting an angle of a rotatable magnetic field source comprises first and second magnetic sensor units for detecting first and second magnetic components of the magnetic field of the magnetic field source, driving means for driving the first and second magnetic sensor unit and control means. The control means control an output signal of the first magnetic sensor unit so as to have a fixed value and the driving means drive the second magnetic sensor unit according to the same drive conditions as those applied to the first magnetic sensor unit at the time when the first magnetic sensor unit is controlled by said control means so that an output signal of the second magnetic sensor unit is proportional to the tangent of said angle.Type: GrantFiled: March 20, 2003Date of Patent: November 29, 2005Assignees: Asahi Kasei EMD Corporation, Sentron AGInventors: Katsumi Kakuta, Christian Schott
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Publication number: 20050127899Abstract: An angle detection apparatus for detecting an angle of a rotatable magnetic field source comprises first and second magnetic sensor units for detecting first and second magnetic components of the magnetic field of the magnetic field source, driving means for driving the first and second magnetic sensor unit and control means. The control means control an output signal of the first magnetic sensor unit so as to have a fixed value and the driving means drive the second magnetic sensor unit according to the same drive conditions as those applied to the first magnetic sensor unit at the time when the first magnetic sensor unit is controlled by said control means so that an output signal of the second magnetic sensor unit is proportional to the tangent of said angle.Type: ApplicationFiled: March 20, 2003Publication date: June 16, 2005Inventors: Katsumi Kakuta, Christian Schott