Patents by Inventor Toshio HIROI

Toshio HIROI 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: 11804659
    Abstract: Provided are an electromagnetic-wave absorbing composition that can favorably absorb electromagnetic waves of high frequencies in or above a millimeter-wave band and that can be applied to a desired portion in the form of a paste, and an easily deformable electromagnetic-wave absorber having flexibility. The electromagnetic-wave absorbing composition includes a rubber binder, a filler made of a particulate carbon material, and a magnetic iron oxide that magnetically resonates in a frequency band in or above a millimeter-wave band as an electromagnetic-wave absorbing material. The electromagnetic-wave absorber includes a rubber binder 1b, a filler 1c made of a particulate carbon material, and a magnetic iron oxide that magnetically resonates in a frequency band in or above a millimeter-wave band as an electromagnetic-wave absorbing material 1a, and is a nonresonant-type electromagnetic-wave absorber that is not provided with a reflective layer for reflecting incident electromagnetic waves.
    Type: Grant
    Filed: July 20, 2018
    Date of Patent: October 31, 2023
    Assignee: Maxell, Ltd.
    Inventors: Toshio Hiroi, Masao Fujita
  • Patent number: 11587705
    Abstract: Provided is an electromagnetic-wave absorber composition and an electromagnetic-wave absorber that can favorably absorb a plurality of electromagnetic waves of different frequencies in a high frequency band in or above the millimeter-wave band. The electromagnetic-wave absorber composition includes a magnetic iron oxide that magnetically resonates at a high frequency in or above the millimeter-wave band and a resin binder. The electromagnetic-wave absorber composition has two or more extrema separated from each other on a differential curve obtained by differentiating a magnetic property hysteresis loop at an applied magnetic field intensity of from 16 kOe to ?16 kOe. The electromagnetic-wave absorber includes an electromagnetic-wave absorbing layer formed of the above-described electromagnetic-wave absorber composition.
    Type: Grant
    Filed: September 12, 2018
    Date of Patent: February 21, 2023
    Assignee: Maxell, Ltd.
    Inventors: Masao Fujita, Toshio Hiroi
  • Patent number: 11515643
    Abstract: An electromagnetic wave absorbing sheet is provided that can adequately absorb electromagnetic waves at high frequencies in and above the millimeter wave band, can have excellent flexibility, and can easily be placed in any desired portion. The electromagnetic wave absorbing sheet includes an electromagnetic wave absorbing layer 1 containing a magnetic iron oxide 1a that magnetically resonates at frequencies in and above the millimeter wave band and a resin binder 1b. The electromagnetic wave absorbing sheet absorbs radiated electromagnetic waves by magnetic resonance of the magnetic iron oxide.
    Type: Grant
    Filed: September 13, 2021
    Date of Patent: November 29, 2022
    Assignee: MAXELL, LTD.
    Inventors: Masao Fujita, Toshio Hiroi
  • Publication number: 20210408695
    Abstract: An electromagnetic wave absorbing sheet is provided that can adequately absorb electromagnetic waves at high frequencies in and above the millimeter wave band, can have excellent flexibility, and can easily be placed in any desired portion. The electromagnetic wave absorbing sheet includes an electromagnetic wave absorbing layer 1 containing a magnetic iron oxide 1a that magnetically resonates at frequencies in and above the millimeter wave band and a resin binder 1b. The electromagnetic wave absorbing sheet absorbs radiated electromagnetic waves by magnetic resonance of the magnetic iron oxide.
    Type: Application
    Filed: September 13, 2021
    Publication date: December 30, 2021
    Applicant: Maxell Holdings, Ltd.
    Inventors: Masao FUJITA, Toshio HIROI
  • Patent number: 11152711
    Abstract: An electromagnetic wave absorbing sheet is provided that can adequately absorb electromagnetic waves at high frequencies in and above the millimeter wave band, can have excellent flexibility, and can easily be placed in any desired portion. The electromagnetic wave absorbing sheet includes an electromagnetic wave absorbing layer 1 containing a magnetic iron oxide 1a that magnetically resonates at frequencies in and above the millimeter wave band and a resin binder 1b. The electromagnetic wave absorbing sheet absorbs radiated electromagnetic waves by magnetic resonance of the magnetic iron oxide.
    Type: Grant
    Filed: November 2, 2017
    Date of Patent: October 19, 2021
    Assignee: Maxell Holdings, Ltd.
    Inventors: Masao Fujita, Toshio Hiroi
  • Patent number: 11100948
    Abstract: The magnetic recording medium disclosed in the present application includes a non-magnetic support, an undercoat layer, a magnetic layer containing magnetic particles, and a back coat layer. The coercive force Hc of the magnetic layer in the thickness direction at 25° C. is not 4100 oersteds (Oe) or more, and the coercive force Hc of the magnetic layer in the thickness direction at a temperature between 55° C. and 80° C. inclusive is not less than 1200 oersteds (Oe) and not more than 3700 oersteds (Oe).
    Type: Grant
    Filed: March 13, 2019
    Date of Patent: August 24, 2021
    Assignee: Maxell Holdings, Ltd.
    Inventors: Shinji Kawakami, Masao Fujita, Toshio Hiroi
  • Publication number: 20210225567
    Abstract: To provide a transmission-type electromagnetic-wave absorber that can satisfactorily absorb electromagnetic waves of high frequencies in or above the millimeter-wave band while reducing the reflection of electromagnetic waves on the surface of the absorber. The transmission-type electromagnetic-wave absorber includes an electromagnetic-wave absorbing layer 1 containing a magnetic iron oxide 1a that magnetically resonates at a frequency in or above the millimeter-wave band and a binder 1b containing an organic material. The real part of the complex relative permittivity of the electromagnetic-wave absorber is 5.5 or less at 1 GHz.
    Type: Application
    Filed: May 31, 2019
    Publication date: July 22, 2021
    Applicant: Maxell Holdings, Ltd.
    Inventors: Toshio HIROI, Masao FUJITA
  • Publication number: 20200265977
    Abstract: Provided is an electromagnetic-wave absorber composition and an electromagnetic-wave absorber that can favorably absorb a plurality of electromagnetic waves of different frequencies in a high frequency band in or above the millimeter-wave band. The electromagnetic-wave absorber composition includes a magnetic iron oxide that magnetically resonates at a high frequency in or above the millimeter-wave band and a resin binder. The electromagnetic-wave absorber composition has two or more extrema separated from each other on a differential curve obtained by differentiating a magnetic property hysteresis loop at an applied magnetic field intensity of from 16 kOe to ?16 kOe. The electromagnetic-wave absorber includes an electromagnetic-wave absorbing layer formed of the above-described electromagnetic-wave absorber composition.
    Type: Application
    Filed: September 12, 2018
    Publication date: August 20, 2020
    Applicant: Maxell Holdings, Ltd.
    Inventors: Masao FUJITA, Toshio HIROI
  • Publication number: 20200267877
    Abstract: Provided is an electromagnetic-wave absorbing sheet that can favorably absorb electromagnetic waves of high frequencies in a frequency band equal to or higher than the millimeter-wave band while having elasticity of elongating in an in-plane direction. The electromagnetic-wave absorbing sheet includes an electromagnetic-wave absorbing layer 1 that contains a magnetic iron oxide 1a that magnetically resonates in a frequency band equal to or higher than the millimeter-wave band as an electromagnetic-wave absorbing material and a rubber binder 1b. The electromagnetic-wave absorbing sheet has a maximum elongation percentage of an elastic region in one in-plane direction of 20% to 200%.
    Type: Application
    Filed: November 2, 2017
    Publication date: August 20, 2020
    Applicant: MAXELL HOLDINGS, LTD.
    Inventors: Toshio HIROI, Masao FUJITA
  • Publication number: 20200227833
    Abstract: Provided are an electromagnetic-wave absorbing composition that can favorably absorb electromagnetic waves of high frequencies in or above a millimeter-wave band and that can be applied to a desired portion in the form of a paste, and an easily deformable electromagnetic-wave absorber having flexibility. The electromagnetic-wave absorbing composition includes a rubber binder, a filler made of a particulate carbon material, and a magnetic iron oxide that magnetically resonates in a frequency band in or above a millimeter-wave band as an electromagnetic-wave absorbing material. The electromagnetic-wave absorber includes a rubber binder 1b, a filler 1c made of a particulate carbon material, and a magnetic iron oxide that magnetically resonates in a frequency band in or above a millimeter-wave band as an electromagnetic-wave absorbing material 1a, and is a nonresonant-type electromagnetic-wave absorber that is not provided with a reflective layer for reflecting incident electromagnetic waves.
    Type: Application
    Filed: July 20, 2018
    Publication date: July 16, 2020
    Applicant: MAXELL HOLDINGS, LTD.
    Inventors: Toshio HIROI, Masao FUJITA
  • Patent number: 10716247
    Abstract: Provided is an electromagnetic-wave absorber that can favorably absorb electromagnetic waves of a plurality of different frequencies in a high frequency band equal to or higher than the millimeter-wave band. The electromagnetic-wave absorber includes an electromagnetic-wave absorbing layer 1 in which a plurality of magnetic layers 1a-1e are stacked, each magnetic layer containing magnetic iron oxide that magnetically resonates at a high frequency in a band equal to or higher than the millimeter-wave band. A value of an anisotropic magnetic field (HA) of the magnetic iron oxide contained in at least one of the magnetic layers is different from that of the magnetic iron oxide contained in another of the magnetic layers.
    Type: Grant
    Filed: July 19, 2017
    Date of Patent: July 14, 2020
    Assignee: MAXELL HOLDINGS, LTD.
    Inventors: Masao Fujita, Toshio Hiroi
  • Patent number: 10614847
    Abstract: In a magnetic recording medium according to the present invention, if a straight line W having a length of 500 nm and a width of 15 nm is displayed parallel to a width direction of the magnetic layer and a straight line L having a length of 500 nm and a width of 15 nm is displayed parallel to a longitudinal direction of the magnetic layer, the number of magnetic particles that intersect the straight line W is N1, and the number of magnetic particles that intersect the straight line L is N2, then, a relationship of N1/0.5>60 and N2/0.5>60 is established where N1/0.5 is the number of magnetic particles per micrometer obtained by dividing N1 by 0.5 ?m and N2/0.5 is the number of magnetic particles per micrometer obtained by dividing N2 by 0.5 ?m.
    Type: Grant
    Filed: December 27, 2017
    Date of Patent: April 7, 2020
    Assignee: MAXELL HOLDINGS, LTD.
    Inventors: Shinji Kawakami, Toshio Hiroi, Masao Fujita
  • Publication number: 20200008328
    Abstract: An electromagnetic-wave absorbing sheet is realized which can favorably absorb electromagnetic waves with a high frequency in or above a millimeter-wave band, and has sufficient elasticity. The electromagnetic-wave absorbing sheet includes: an electromagnetic-wave absorbing layer 1 that includes a particulate electromagnetic-wave absorbing material 1a and a rubber binder 1b; and a dielectric layer 2 arranged on a back surface of the electromagnetic-wave absorbing layer. The electromagnetic-wave absorbing material is a magnetic iron oxide that magnetically resonates in a frequency band that is at least a millimeter-wave band. The dielectric layer is non-magnetic and has flexibility, a real part of a complex relative permittivity of the dielectric layer is 2 or more and 6 or less, and the dielectric layer has a thickness of 10 ?m or more and 100 ?m or less.
    Type: Application
    Filed: March 13, 2018
    Publication date: January 2, 2020
    Applicant: MAXELL HOLDINGS, LTD.
    Inventors: Toshio HIROI, Masao FUJITA
  • Publication number: 20190312356
    Abstract: An electromagnetic wave absorbing sheet is provided that can adequately absorb electromagnetic waves at high frequencies in and above the millimeter wave band, can have excellent flexibility, and can easily be placed in any desired portion. The electromagnetic wave absorbing sheet includes an electromagnetic wave absorbing layer 1 containing a magnetic iron oxide 1a that magnetically resonates at frequencies in and above the millimeter wave band and a resin binder 1b. The electromagnetic wave absorbing sheet absorbs radiated electromagnetic waves by magnetic resonance of the magnetic iron oxide.
    Type: Application
    Filed: November 2, 2017
    Publication date: October 10, 2019
    Applicant: Maxell Holdings, Ltd.
    Inventors: Masao FUJITA, Toshio HIROI
  • Publication number: 20190287562
    Abstract: The magnetic recording medium disclosed in the present application includes a non-magnetic support, an undercoat layer, a magnetic layer containing magnetic particles, and a back coat layer. The coercive force Hc of the magnetic layer in the thickness direction at 25° C. is not 4100 oersteds (Oe) or more, and the coercive force Hc of the magnetic layer in the thickness direction at a temperature between 55° C. and 80° C. inclusive is not less than 1200 oersteds (Oe) and not more than 3700 oersteds (Oe).
    Type: Application
    Filed: March 13, 2019
    Publication date: September 19, 2019
    Applicant: Maxell Holdings, Ltd.
    Inventors: Shinji KAWAKAMI, Masao FUJITA, Toshio HIROI
  • Publication number: 20190269048
    Abstract: Provided is an electromagnetic-wave absorber that can favorably absorb electromagnetic waves of a plurality of different frequencies in a high frequency band equal to or higher than the millimeter-wave band. The electromagnetic-wave absorber includes an electromagnetic-wave absorbing layer 1 in which a plurality of magnetic layers 1a-1e are stacked, each magnetic layer containing magnetic iron oxide that magnetically resonates at a high frequency in a band equal to or higher than the millimeter-wave band. A value of an anisotropic magnetic field (HA) of the magnetic iron oxide contained in at least one of the magnetic layers is different from that of the magnetic iron oxide contained in another of the magnetic layers.
    Type: Application
    Filed: July 19, 2017
    Publication date: August 29, 2019
    Applicant: Maxell Holdings, Ltd.
    Inventors: Masao FUJITA, Toshio HIROI
  • Publication number: 20190215994
    Abstract: Provided is an electric-wave absorbing sheet that can favorably absorb high frequency electric waves in the millimeter-wave band or higher and that has high handleability. The electric-wave absorbing sheet includes a flexible electric-wave absorbing layer 1 that contains a particulate electric-wave absorbing material 1a and a resin binder 1b. The electric-wave absorbing material is a magnetic iron oxide that magnetically resonates at a frequency band equal to or higher than the millimeter-wave band.
    Type: Application
    Filed: June 21, 2017
    Publication date: July 11, 2019
    Applicant: Maxell Holdings, Ltd.
    Inventors: Toshio HIROI, Masao FUJITA, Makoto TERASAWA
  • Patent number: 10255938
    Abstract: A magnetic recording medium of the present invention includes a non-magnetic substrate, and a magnetic layer containing a magnetic powder. The magnetic powder is constituted by an ?-iron oxide powder. The magnetic layer has a squareness in a thickness direction of 0.65 or more. In a differential curve obtained by differentiating a hysteresis curve in the thickness direction of the magnetic layer, two or more peaks are present. In a case where, out of peaks in the same direction among the above-described peaks, a local maximum of a largest peak in a magnetic field range of +500 oersted [Oe] or more is taken as P1 and a local maximum of a largest peak in a magnetic field range of ?500 oersted [Oe] or more and less than +500 oersted [Oe] is taken as P2, a relationship below is satisfied: 0.25?P2/P1?0.60.
    Type: Grant
    Filed: January 31, 2017
    Date of Patent: April 9, 2019
    Assignee: MAXELL HOLDINGS, LTD.
    Inventors: Toshio Hiroi, Shinji Kawakami, Kenji Tanaka
  • Publication number: 20180182422
    Abstract: In a magnetic recording medium according to the present invention, if a straight line W having a length of 500 nm and a width of 15 nm is displayed parallel to a width direction of the magnetic layer and a straight line L having a length of 500 nm and a width of 15 nm is displayed parallel to a longitudinal direction of the magnetic layer, the number of magnetic particles that intersect the straight line W is N1, and the number of magnetic particles that intersect the straight line L is N2, then, a relationship of N1/0.5>60 and N2/0.5>60 is established where N1/0.5 is the number of magnetic particles per micrometer obtained by dividing N1 by 0.5 ?m and N2/0.5 is the number of magnetic particles per micrometer obtained by dividing N2 by 0.5 ?m.
    Type: Application
    Filed: December 27, 2017
    Publication date: June 28, 2018
    Applicant: Maxell Holdings, Ltd.
    Inventors: Shinji KAWAKAMI, Toshio HIROI, Masao FUJITA
  • Publication number: 20170221513
    Abstract: A magnetic recording medium of the present invention includes a non-magnetic substrate, and a magnetic layer containing a magnetic powder. The magnetic powder is constituted by an ?-iron oxide powder. The magnetic layer has a squareness in a thickness direction of 0.65 or more. In a differential curve obtained by differentiating a hysteresis curve in the thickness direction of the magnetic layer, two or more peaks are present. In a case where, out of peaks in the same direction among the above-described peaks, a local maximum of a largest peak in a magnetic field range of +500 oersted [Oe] or more is taken as P1 and a local maximum of a largest peak in a magnetic field range of ?500 oersted [Oe] or more and less than +500 oersted [Oe] is taken as P2, a relationship below is satisfied: 0.25?P2/P1?0.60.
    Type: Application
    Filed: January 31, 2017
    Publication date: August 3, 2017
    Applicant: HITACHI MAXELL, LTD.
    Inventors: Toshio HIROI, Shinji KAWAKAMI, Kenji TANAKA