Patents by Inventor Naoyasu Iketani

Naoyasu Iketani 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).

  • Publication number: 20160142050
    Abstract: Provided are a multiple-unit semiconductor device that enables space savings and a method for controlling such a semiconductor device. A multiple-unit semiconductor device is brought into conduction by a Si-FET being brought into conduction first and a GaN device being brought into conduction after the Si-FET has been brought into conduction.
    Type: Application
    Filed: June 6, 2014
    Publication date: May 19, 2016
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Naoyasu IKETANI, Akio NAKAJIMA, Kohsuke INNAMI
  • Publication number: 20160056131
    Abstract: A primary surface of a normally-off field-effect transistor (102) on which a source electrode (120) is formed and a first primary surface of a die pad (105) are in contact with each other, and the die pad (105) also serves as a source terminal of a semiconductor device (100). Accordingly, a semiconductor device capable of decreasing an inductance, which is a matter of great importance for an operation of a cascode connection circuit, and improving performance of circuit operation is provided.
    Type: Application
    Filed: February 28, 2014
    Publication date: February 25, 2016
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Tomotoshi SATOH, Eiji OGINO, Naoyasu IKETANI, Satoshi MORISHITA
  • Patent number: 8766275
    Abstract: This composite semiconductor device has a normally-on first field effect transistor and a normally-off second field effect transistor connected in series between first and second terminals, gates of the first and second field effect transistors being connected to second and third terminals, respectively, and N diodes being connected in series in a forward direction between a drain and a source of the second field effect transistor. Therefore, a drain-source voltage (Vds) of the second field effect transistor can be restricted to a voltage not higher than a withstand voltage of the second field effect transistor.
    Type: Grant
    Filed: December 28, 2010
    Date of Patent: July 1, 2014
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Naoyasu Iketani, Tomohiro Nozawa, Yoshiaki Nozaki, John K. Twynam, Hiroshi Kawamura, Keiichi Sakuno
  • Publication number: 20120292635
    Abstract: This composite semiconductor device has a normally-on first field effect transistor and a normally-off second field effect transistor connected in series between first and second terminals, gates of the first and second field effect transistors being connected to second and third terminals, respectively, and N diodes being connected in series in a forward direction between a drain and a source of the second field effect transistor. Therefore, a drain-source voltage (Vds) of the second field effect transistor can be restricted to a voltage not higher than a withstand voltage of the second field effect transistor.
    Type: Application
    Filed: December 28, 2010
    Publication date: November 22, 2012
    Inventors: Naoyasu Iketani, Tomohiro Nozawa, Yoshiaki Nozaki, John K. Twynam, Hiroshi Kawamura, Keiichi Sakuno
  • Patent number: 7690009
    Abstract: An electromagnetic field generating element restrains magnetic field attenuation or magnetic field delay in a high frequency recording/reproducing head for thermally assisted magnetic field recording/reproduction using a near field. An information recording/reproducing head and an information recording/reproducing apparatus carry out high frequency magnetic recording/reproduction. The electromagnetic field generating element includes: (i) a substrate, (ii) conductors each provided on the substrate and each serving as a supporting section, (iii) a plate-like-shaped conductor provided on the conductors and (iv) a semiconductor laser element provided on the substrate. The semiconductor laser element irradiates laser light to the plate-like-shaped conductor substantially parallel to an extending flat surface of the plate-like-shaped conductor. This causes generation of a near field in the plate-like-shaped conductor.
    Type: Grant
    Filed: December 12, 2008
    Date of Patent: March 30, 2010
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Shintaro Miyanishi, Naoyasu Iketani, Kunio Kojima
  • Publication number: 20090106783
    Abstract: The present invention provides an electromagnetic field generating element, an information recording/reproducing head, and an information recording/reproducing apparatus. The electromagnetic field generating element makes it possible to restrain magnetic field attenuation or magnetic field delay in a high frequency recording/reproducing head for use in thermally assisted magnetic field recording/reproduction using a near field. The information recording/reproducing head and the information recording/reproducing apparatus can carry out high frequency magnetic recording/reproducing. The electromagnetic field generating element of the present invention includes: (i) a substrate, (ii) conductors each provided on the substrate and each serving as a supporting section, (iii) a plate-like-shaped conductor provided on the conductors and (iv) a semiconductor laser element provided on the substrate.
    Type: Application
    Filed: December 12, 2008
    Publication date: April 23, 2009
    Applicant: Sharp Kabushiki Kaisha
    Inventors: Shintaro Miyanishi, Naoyasu Iketani, Kunio Kojima
  • Patent number: 7489597
    Abstract: An electromagnetic field generating element restrains magnetic field attenuation or magnetic field delay in a high frequency recording/reproducing head for thermally assisted magnetic field recording/reproduction using a near field. An information recording/reproducing head and an information recording/reproducing apparatus carry out high frequency magnetic recording/reproduction. The electromagnetic field generating element includes: (i) a substrate, (ii) conductors each provided on the substrate and each serving as a supporting section, (iii) a plate-like-shaped conductor provided on the conductors and (iv) a semiconductor laser element provided on the substrate. The semiconductor laser element irradiates laser light to the plate-like-shaped conductor substantially parallel to an extending flat surface of the plate-like-shaped conductor. This causes generation of a near field in the plate-like-shaped conductor.
    Type: Grant
    Filed: September 27, 2005
    Date of Patent: February 10, 2009
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Shintaro Miyanishi, Naoyasu Iketani, Kunio Kojima
  • Publication number: 20060075417
    Abstract: The present invention provides an electromagnetic field generating element, an information recording/reproducing head, and an information recording/reproducing apparatus. The electromagnetic field generating element makes it possible to restrain magnetic field attenuation or magnetic field delay in a high frequency recording/reproducing head for use in thermally assisted magnetic field recording/reproduction using a near field. The information recording/reproducing head and the information recording/reproducing apparatus can carry out high frequency magnetic recording/reproducing. The electromagnetic field generating element of the present invention includes: (i) a substrate, (ii) conductors each provided on the substrate and each serving as a supporting section, (iii) a plate-like-shaped conductor provided on the conductors and (iv) a semiconductor laser element provided on the substrate.
    Type: Application
    Filed: September 27, 2005
    Publication date: April 6, 2006
    Inventors: Shintaro Miyanishi, Naoyasu Iketani, Kunio Kojima
  • Publication number: 20050213436
    Abstract: In a read/write device for writing and reading a storage medium by way of a heat assisted magnetic recording/reproduction scheme, the read/write device including an elevated slider provided with a semiconductor laser, provided is a heat dissipation mechanism for dissipating heat generated in the elevated slider to an outside of a housing of the read/write device. Further, the storage medium has a second heatsink layer formed of an Al film having a thickness of 50 ?m, a backing layer, a heat barrier layer, a first heatsink layer, a magnetic recording layer, and a protection film on a glass substrate. With this arrangement, in a read/write device which performs a heat assisted magnetic recording and reproduction by a semiconductor laser provided on the elevated slider, the occurrence of malfunction due to temperature rises in the storage medium is prevented.
    Type: Application
    Filed: March 29, 2005
    Publication date: September 29, 2005
    Inventors: Tomoki Ono, Naoyasu Iketani
  • Patent number: 6707766
    Abstract: A magneto-optical storage medium includes an interference layer, a magnetic domain expansion layer, an intermediate layer, a magnetic masking layer, a recording layer, and a protection layer which are sequentially formed on a substrate. The magnetic domain expansion layer produces a smaller frictional force due to wall coercivity than do the other magnetic layers. The intermediate layer has the Curie temperature TC2 which is lower than those of the other magnetic layers. The magnetic masking layer is in a perpendicular magnetization state at temperatures that are in a proximity of TC2, and changes into an in-plane magnetization state at temperatures that are higher than the proximity of TC2. The recording layer produces a higher coercive force than those produced by the magnetic domain expansion layer at room temperature.
    Type: Grant
    Filed: March 19, 2002
    Date of Patent: March 16, 2004
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Go Mori, Naoyasu Iketani, Michinobu Mieda, Akira Takahashi
  • Patent number: 6665235
    Abstract: Featured is a recording and reproducing method of a magneto-optical recording medium including a recording layer for recording thereon information magneto-optically and a readout layer which has in-plane magnetization at room temperature and where a transition occurs from in-plane magnetization to perpendicular magnetization as temperature raises. The method includes projecting a light beam onto such a magneto-optical recording medium so as to form a perpendicularly magnetized area in the readout layer by duplication of the magnetization of said recording layer to the area. In further embodiments, the recording medium further includes an intermediate layer made of non-magnetic film formed between the readout and recording layers and the readout and recording layers are composed of rare-earth transition metal alloys such as TbFeCo (recoding layer) readout layer, made of GdFeCo (readout layer).
    Type: Grant
    Filed: August 8, 2002
    Date of Patent: December 16, 2003
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yoshiteru Murakami, Junji Hirokane, Junichiro Nakayama, Junsaku Nakajima, Akira Takahashi, Kenji Ohta, Naoyasu Iketani
  • Publication number: 20030081510
    Abstract: A magneto-optical recording medium is composed of a base which has a property that a light can be transmitted therethrough, a readout layer formed on the base, which has in-plane magnetization at room temperature, whereas, a transition occurs from in-plane magnetization to perpendicular magnetization as the temperature thereof is raised and a recording layer formed on the readout layer for recording information magneto-optically. A recording and reproducing method and the optical head are designed for the magneto-optical recording medium. By the recording and reproducing method using the optical head, information recorded at high density can be reproduced.
    Type: Application
    Filed: August 8, 2002
    Publication date: May 1, 2003
    Applicant: Sharp Kabushiki Kaisha
    Inventors: Yoshiteru Murakami, Junji Hirokane, Junichiro Nakayama, Junsaku Nakajima, Akira Takahashi, Kenji Ohta, Naoyasu Iketani
  • Patent number: 6483785
    Abstract: Featured is a recording and reproducing method for recording and reproducing information on and from a recording medium. The medium includes a base having a property that a light can be transmitted therethrough, a readout layer formed on the base, which has an in-plane magnetization at room temperature, whereas, a transition occurs from in-plane magnetization to perpendicular magnetization as temperature rises and a recording layer formed on said readout layer for recording thereon information magneto-optically. A groove for guiding a light beam is formed on a readout layer side of the base and a groove width is set substantially equal to a land width formed between grooves. The recording layer on the grooves and the recording layer on lands are used in recording and reproducing information.
    Type: Grant
    Filed: October 10, 2000
    Date of Patent: November 19, 2002
    Inventors: Yoshiteru Murakami, Junji Hirokane, Junichiro Nakayama, Junsaku Nakajima, Akira Takahashi, Kenji Ohta, Naoyasu Iketani
  • Patent number: 6477120
    Abstract: In order to provide a magneto-optical recording medium which can select a single recording magnetic domain in the recording layer accurately and expand and transfer the same to the reproducing layer, the magneto-optical recording medium is arranged in the following manner. That is, the magnetization direction of the reproducing layer is in-plane at room temperature and shifts to perpendicular at or above a predetermined temperature Ttrans.. The recording layer is a magnetic layer which is magneto-statically coupled to the reproducing layer and shows the perpendicular magnetization up to its Curie temperature. The magnetic mask layer is provided between the recording layer and reproducing layer, and the magnetization thereof is reduced to 0 (zero) at or above a predetermined temperature (Tm) which is at or above Ttrans.. The magnetization of the magnetic mask layer is larger than that of the recording layer at least in a range between room temperature and Ttrans..
    Type: Grant
    Filed: November 30, 1999
    Date of Patent: November 5, 2002
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Naoyasu Iketani, Go Mori, Michinobu Mieda, Akira Takahashi
  • Publication number: 20020136097
    Abstract: A magneto-optical storage medium includes an interference layer, a magnetic domain expansion layer, an intermediate layer, a magnetic masking layer, a recording layer, and a protection layer which are sequentially formed on a substrate. The magnetic domain expansion layer produces a smaller frictional force due to wall coercivity than do the other magnetic layers. The intermediate layer has the Curie temperature TC2 which is lower than those of the other magnetic layers. The magnetic masking layer is in a perpendicular magnetization state at temperatures that are in a proximity of TC2, and changes into an in-plane magnetization state at temperatures that are higher than the proximity of TC2. The recording layer produces a higher coercive force than those produced by the magnetic domain expansion layer at room temperature.
    Type: Application
    Filed: March 19, 2002
    Publication date: September 26, 2002
    Applicant: Sharp Kabushiki Kaisha
    Inventors: Go Mori, Naoyasu Iketani, Michinobu Mieda, Akira Takahashi
  • Patent number: 6456586
    Abstract: A magneto-optical recording medium comprising a reproducing magnetic layer having a magnetic layer which is in an in-plane magnetization state at room temperature but shifts to a perpendicular magnetization state as temperature rises, a dielectric layer and a recording magnetic layer having a magnetic layer which exhibits a perpendicular magnetization, sequentially from a photo-receptive side, the recording medium being further comprising a metal layer between the reproducing magnetic layer and the dielectric layer.
    Type: Grant
    Filed: September 9, 1999
    Date of Patent: September 24, 2002
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Ippei Suzuki, Naoyasu Iketani, Yoshiteru Murakami, Akira Takahashi
  • Patent number: 6388956
    Abstract: A magneto-optical storage medium includes an interference layer, a magnetic domain expansion layer, an intermediate layer, a magnetic masking layer, a recording layer, and a protection layer which are sequentially formed on a substrate. The magnetic domain expansion layer produces a smaller frictional force due to wall coercivity than do the other magnetic layers. The intermediate layer has the Curie temperature TC2 which is lower than those of the other magnetic layers. The magnetic masking layer is in a perpendicular magnetization state at temperatures that are in a proximity of TC2, and changes into an in-plane magnetization state at temperatures that are higher than the proximity of TC2. The recording layer produces a higher coercive force than those produced by the magnetic domain expansion layer at room temperature.
    Type: Grant
    Filed: November 16, 1999
    Date of Patent: May 14, 2002
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Go Mori, Naoyasu Iketani, Michinobu Mieda, Akira Takahashi
  • Patent number: 6338911
    Abstract: A reproduction layer, a magnetic domain extending layer, an intermediate layer, and a recording layer are formed in this order. The magnetic domain extending layer, the intermediate layer, and the recording layer are exchange-coupled. The intermediate layer has a Curie temperature lower than that of any other magnetic layer. A non-magnetic intermediate layer is formed between the reproduction layer and the magnetic domain extending layer. Upon reproduction, magnetization information in the recording layer is transferred to and extended in the magnetic domain extending layer, where an extended magnetic domain is formed. The reproduction layer is magnetostatically coupled with the magnetic domain extending layer, so that the extended magnetic domain is transferred to the reproduction layer.
    Type: Grant
    Filed: October 29, 1999
    Date of Patent: January 15, 2002
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Go Mori, Naoyasu Iketani, Michinobu Mieda, Akira Takahashi
  • Patent number: 6298018
    Abstract: An optical disk is provided with a recording layer, and with an optical coupling layer on a light-incident side of the recording layer. An optical recording and reproducing device and method include an objective lens and a hemispherical lens, which converge a light beam from a light source and project the light beam onto the optical disk. The hemispherical lens is provided in close proximity to the optical coupling layer, in a position such that an interval therebetween is not more than the wavelength of the light produced by the light source. The light beam converged by the objective lens and the hemispherical lens is coupled with the optical coupling layer while substantially maintaining a direction of propagation in which it was propagating while inside the hemispherical lens.
    Type: Grant
    Filed: March 8, 1999
    Date of Patent: October 2, 2001
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Akira Takahashi, Yoshiteru Murakami, Naoyasu Iketani, Ippei Suzuki, Go Mori, Shinya Hirata
  • Patent number: 6295271
    Abstract: An optical disk has address recording sections each of which has a wobbled part of one of side walls of a groove. Each address recording section is formed by providing convexes of a groove in an adjacent land so as to widen the groove. With the wobbles thus provided in a concavo-convex form, address information is recorded. Besides, the address recording sections thus provided in the grooves are linearly disposed in radial directions of the optical disk. By thus arranging the optical disk on whose grooves and/or lands information is recorded, mixing of wobble frequency components in reproduced information signals does not occur, the sector method is applicable to the optical disk, and information signals of high quality can be obtained.
    Type: Grant
    Filed: December 30, 1999
    Date of Patent: September 25, 2001
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Tetsuya Inui, Hideaki Sato, Junichiro Nakayama, Naoyasu Iketani, Michinobu Mieda, Yoshiteru Murakami, Junji Hirokane, Akira Takahashi