Patents Assigned to TDK Corporation
  • Publication number: 20040090704
    Abstract: Provided is a thin film magnetic head capable of appropriately control the flow of magnetic flux from a yoke layer to a pole layer so as to prevent information from being overwritten without intention during recording. A perpendicular recording system thin film magnetic head is formed so that a portion of a yoke layer and a portion of a pole layer are connected to each other in a connecting surface. When a large amount of the magnetic flux contained in the yoke layer flows into the pole layer through the connecting surface, the large amount of the magnetic flux is concentrated in the connecting surface, so an excessive amount of the magnetic flux is not supplied to a front end portion of the pole layer, and an appropriate amount of the magnetic flux is supplied.
    Type: Application
    Filed: November 4, 2003
    Publication date: May 13, 2004
    Applicants: TDK CORPORATION, SAE MAGNETICS (H.K.) LTD.
    Inventors: Naoto Matono, Tetsuya Roppongi, Norikazu Ota
  • Publication number: 20040090288
    Abstract: The SAW element 11 comprises a serial arm 17 formed between an input terminal 15 and an output terminal 16, two serial arm side SAW resonators 20 located in the serial arm 17, at least three parallel arms 19 connected between the serial arm 17 and a reference potential terminal 18, and parallel arm side SAW resonator 21 located in the parallel arms 19, respectively. Each of these parallel arm side SAW resonators 21 has an anti-resonant frequency corresponding with the predetermined resonant frequency of each serial arm side SAW resonator 20. Further, at least one parallel arm side SAW resonator 21 has a resonant frequency different from those of the other parallel arm side SAW resonators 21. Thereby, not only insertion loss can be prevented from being deteriorated but also an attenuation characteristic of the SAW element 11 can be readily varied.
    Type: Application
    Filed: November 4, 2003
    Publication date: May 13, 2004
    Applicant: TDK Corporation
    Inventor: Kenji Inoue
  • Publication number: 20040090302
    Abstract: An Mn—Zn ferrite wherein 0 to 5000 ppm of a Co oxide in a CO3O4 conversion is contained in a basic component constituted by Fe2O3: 51.5 to 57.0 mol % and ZnO: 0 to 15 mol % (note that 0 is not included) wherein the rest is substantially constituted by MnO; and a value &agr; in a formula (1) below in said ferrite satisfies &agr;≧0.93.
    Type: Application
    Filed: August 29, 2003
    Publication date: May 13, 2004
    Applicant: TDK CORPORATION
    Inventors: Yuji Sezai, Katsushi Yasuhara, Kenya Takagawa, Masahiko Watanabe
  • Publication number: 20040091007
    Abstract: A semiconductor laser driving circuit comprises a driving IC and a substrate on which the IC is mounted. The IC incorporates: a switching element for generating a driving signal; a high-potential power terminal and a low-potential power terminal for feeding supply voltage to the switching element; and a driving signal output terminal for outputting the driving signal generated at the switching element to an external device. These three terminals are disposed side by side at one of sides of a main body of the IC. The substrate incorporates three conductors to be connected to the three terminals. Two chip capacitors are disposed beside the one of the sides of the IC at which the three terminals are disposed. An end of each of the capacitors is connected to the high-potential power terminal while the other end is connected to the low-potential power terminal.
    Type: Application
    Filed: April 3, 2003
    Publication date: May 13, 2004
    Applicant: TDK Corporation
    Inventor: Giichi Shibuya
  • Publication number: 20040090710
    Abstract: A load beam is provided with a base plate and a slider. A magnetic head apparatus is fixed to a head arm via a base plate. In a mechanism or structure for supporting such a magnetic head supporting mechanism, an elastically deformable portion is provided between the base plate and the load beam. Thus, a floating structure that allows the load beam to swing is formed about the elastically deformable portion. In addition, a weight of the load beam is balanced with respect to the elastically deformable portion. Furthermore, a contact portion for applying pressure to the load beam is provided on the head arm so that a pressing load to a recording medium would be set by an amount of rotation of the load beam caused by the pressure applied by the contact portion.
    Type: Application
    Filed: June 27, 2003
    Publication date: May 13, 2004
    Applicants: TDK CORPORATION, MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.
    Inventors: Takashi Honda, Katsuki Kurihara, Yoshihiro Ueno, Hideki Kuwajima
  • Publication number: 20040089472
    Abstract: This invention provides a multilayer ceramic substrate which has a consistent quality, and which has with no swelling or collapse in the inner periphery of the cavity, wherein the bottom of the cavity is flat to enable stable packaging of the desired device at a high precision, and wherein L and C can be formed by the internal conductor at a high precision; and a method for producing a multilayer ceramic substrate and an apparatus therefor by which a multilayer ceramic substrate can be readily produced in a simple procedure by using an apparatus of simple structure.
    Type: Application
    Filed: January 31, 2003
    Publication date: May 13, 2004
    Applicant: TDK CORPORATION
    Inventors: Hideaki Ninomiya, Haruo Nishino, Kiyoshi Hatanaka
  • Patent number: 6735056
    Abstract: An electron device includes a first layer formed of a metal or metal alloy and a second layer adjoining the first layer and formed of a metal or metal alloy different from that of the first layer. In the region adjacent the first layer and the second layer, there is provided a concentration gradient layer formed of a mixture containing a metal or metal alloy contained in the first layer and a metal or metal alloy contained in the second layer. A covering film covers end faces of the first and second layers. With this arrangement, when a cleaning as by etching is carried out on the end faces of the multilayered film structure of the electron device, the end faces are etched in relatively smoothly connected surfaces because of the etched end face of the concentration gradient layer in a gentle slope, so that coverage of the covering film on the end faces of the multilayered film structure can be improved to increase the adherence strength of the covering film.
    Type: Grant
    Filed: April 16, 2002
    Date of Patent: May 11, 2004
    Assignee: TDK Corporation
    Inventors: Katsuaki Yanagiuchi, Wakako Shiramura
  • Patent number: 6734764
    Abstract: A shield that can prevent the thickness of a dielectric filter from increasing without increasing the manufacturing cost of the dielectric filter is disclosed. The shield of the present invention is to be attached to a dielectric filter and has a first plate, a second plate elongated from the first end of the first plate in a predetermined direction, a third plate elongated from the second end of the first plate opposite to the first end in the predetermined direction, and a projecting part projecting from the first plate at a portion between the first and second ends of the first plate. Since the shield can be fixed to the dielectric filter by pinching the both side of the dielectric block and the projecting part can be in contact with the metallization of the dielectric filter, the total thickness of the dielectric filter does not increase even the shield is attached.
    Type: Grant
    Filed: March 28, 2002
    Date of Patent: May 11, 2004
    Assignee: TDK Corporation
    Inventors: Kenji Endou, Osamu Takubo
  • Patent number: 6733858
    Abstract: Provided is a medium having a phase change recording layer wherein crystallization of the recording layer is facilitated, and at the same time, wherein the region to be crystallized is crystallized at an accurate dimension. The optical recording medium has a recording layer 4 comprising at least one phase change layer 41 and at least one functional layer 42 in contact with said phase change layer. The phase change layer 41 in its as-deposited state is amorphous, and crystals having Fm3m structure or R3m structure are produced upon crystallization of this layer. The functional layer 42 in its as-deposited state is crystalline, and contains crystals having Fm3m structure. The material used for the functional layer 42 is the one which exhibits a thermal conductivity of 0.03 to 5 W/cmK as measured in thin film form of 100 nm thick.
    Type: Grant
    Filed: October 2, 2001
    Date of Patent: May 11, 2004
    Assignee: TDK Corporation
    Inventors: Tetsuro Mizushima, Jiro Yoshinari
  • Patent number: 6735059
    Abstract: A magnetoresistive effective type element, comprising: a magnetoresistive effective film; a first shielding film of which one main surface is adjacent to one main surface of said magnetoresistive effective film; a second shielding film of which one main surface is adjacent to the other main surface of said magnetoresistive effective film; and a third shielding film of which one main surface is adjacent to the other main surface of said first shielding film or said second shielding film opposite to said magnetoresistive effective film, wherein said first shielding film and said second shielding film function as current-supplying layers to flow current perpendicular to and through said magnetoresistive effective film, and wherein said first shielding film and said second shielding film are made of at least one selected from the group consisting of NiFe, CoZrTa, FeN, FeAlSi, NiFe alloy, Co-based amorphous material and Fe-based soft magnetic material.
    Type: Grant
    Filed: April 10, 2002
    Date of Patent: May 11, 2004
    Assignee: TDK Corporation
    Inventor: Junichi Sato
  • Patent number: 6734469
    Abstract: An object of the invention is to provide an EL phosphor laminate thin film and EL device which can emit light at a high luminance. The object is achieved by stacking a phosphor thin film and a dielectric thin film one on the other wherein the phosphor thin film comprises at least one compound selected from an alkaline earth thioaluminate, an alkaline earth thiogallate and an alkaline earth thioindate as a main component, and a rare earth element as a luminescence center, and the dielectric thin film comprises an alkaline earth-containing oxide and/or a titanium-containing oxide.
    Type: Grant
    Filed: November 19, 2001
    Date of Patent: May 11, 2004
    Assignee: TDK Corporation
    Inventors: Yoshihiko Yano, Tomoyuki Oike, Yukihiko Shirakawa, Katsuto Nagano
  • Publication number: 20040085887
    Abstract: A data recording method of modulating the power of a laser beam in accordance with a pulse pattern, projecting the laser beam onto a write-once type optical recording medium to form a record mark and recording data in the write-once type optical recording medium, wherein the pulse pattern is constituted by a pattern in which the power of the laser beam is set to a recording power Pw within a first period and a second period and the power of the laser beam is set to an intermediate power Pm lower than the recording power Pw within a third period provided between the first period and the second period, the length of the first period and the levels of the recording power Pw and the intermediate power Pw being set to satisfy 1.7T≦ttop2 and 1.4≦Pw/Pm where T is a length corresponding to one cycle of a reference pulse and ttop2 is the length of the first period.
    Type: Application
    Filed: October 24, 2003
    Publication date: May 6, 2004
    Applicant: TDK Corporation
    Inventors: Takashi Horai, Hiroyuki Arioka, Narutoshi Fukuzawa, Syuji Tsukamoto
  • Publication number: 20040085151
    Abstract: The present invention is directed to enable mode conversion between a TEM mode and another mode to be performed among a plurality of waveguides. An RF module comprises: a microstrip line as a first waveguide for propagating electromagnetic waves in a TEM mode; and a waveguide having a multilayer structure as a second waveguide connected to the first waveguide, for propagating electromagnetic waves in another mode different from the TEM mode. An end of the first waveguide is directly or indirectly connected so as to be conductive to one of ground electrodes of the second waveguide from the direction orthogonal to the stacking direction of the ground electrodes. Since magnetic fields are coupled so that the direction of the magnetic field of the first waveguide and that of the magnetic field of the second waveguide match with each other in the E plane, mode conversion between the TEM mode and another mode to be excellently performed between the waveguides.
    Type: Application
    Filed: October 27, 2003
    Publication date: May 6, 2004
    Applicant: TDK CORPORATION
    Inventor: Tatsuya Fukunaga
  • Publication number: 20040085153
    Abstract: The present invention is directed to enable mode conversion between a TEM mode and another mode to be performed among a plurality of waveguides. An RF module comprises: a TEM waveguide as a first waveguide for propagating electromagnetic waves in a TEM mode; and a waveguide having a multilayer structure as a second waveguide connected to the first waveguide, for propagating electromagnetic waves in another mode different from the TEM mode. An end of the first waveguide is directly conductively connected to one of ground electrodes of the second waveguide from the stacking direction side of the ground electrodes. Since magnetic fields are coupled so that the direction of the magnetic field of the first waveguide and that of the magnetic field of the second waveguide match with each other in the H plane, mode conversion between the TEM mode and another mode can be excellently performed between the waveguides.
    Type: Application
    Filed: October 27, 2003
    Publication date: May 6, 2004
    Applicant: TDK CORPORATION
    Inventor: Tatsuya Fukunaga
  • Publication number: 20040084999
    Abstract: A piezoelectric device includes electrode films and piezoelectric ceramic layers. The piezoelectric ceramic layers have a number of at least 4 and are alternately laminated with the electrode films. A first support member has a first projection, whereas a second support member has a second projection. The first and second support members are arranged such that the first and second projections are opposed to each other. The piezoelectric device is disposed between the first and second projections, and is held by end faces of the first and second projections.
    Type: Application
    Filed: January 21, 2003
    Publication date: May 6, 2004
    Applicant: TDK CORPORATION
    Inventor: Katsumi Yamauchi
  • Patent number: 6731474
    Abstract: Provided are a thin film magnetic head and a method of manufacturing the same, which is capable of high density recording and obtaining stable output. The thin film magnetic head includes an MR film sandwiched in between first and second shield layers. The first shield layer includes an inner layer, a magnetization stabilizing layer, an underlayer, and an outer layer laminated in order from the MR film. The second shield layer includes an inner layer, a magnetization stabilizing layer, an isolating layer, and an outer layer laminated in order from the MR film. The magnetization stabilizing layers are formed of antiferromagnetic material, so as to control the direction of magnetization of the inner layers.
    Type: Grant
    Filed: November 26, 2001
    Date of Patent: May 4, 2004
    Assignee: TDK Corporation
    Inventors: Koichi Terunuma, Ken-ichi Takano, Noriyuki Ito
  • Patent number: 6729012
    Abstract: A method of manufacturing a thin-film magnetic head comprises the steps of forming a bottom pole layer, forming a gap layer, forming a top pole layer, and forming a thin-film coil. The thin-film coil is wound around the top pole layer in a helical manner. In the step of forming the bottom pole layer, the bottom pole layer is formed to include a first layer facing a portion of the thin-film coil, and a second layer that forms a pole portion and is connected to a surface of the first layer facing the top pole layer. In the step of forming the thin-film coil, a portion of the coil is disposed on a side of the second layer and another portion of the coil is disposed over the top pole layer via an insulating film.
    Type: Grant
    Filed: April 14, 2000
    Date of Patent: May 4, 2004
    Assignee: TDK Corporation
    Inventor: Yoshitaka Sasaki
  • Patent number: 6731373
    Abstract: In order to imprint wafer-identifying information on a wafer on which a plurality of thin-film devices are formed in a batch, utilizing a patterned resist layer, an exposure apparatus exposes a resist layer formed on the wafer to light for forming a latent image of the wafer-identifying information. The exposure apparatus allows a mask storage controller and a mask transfer device to select a mask, on which the pattern of a numeral or symbol to be imprinted is drawn, for each digit of the wafer-identifying information and carries out exposure. The exposure apparatus also allows a mask shift controller to change the positional relationship between the wafer and the mask for each digit of the wafer-identifying information so that the numeral or symbol of each digit of the wafer-identifying information is imprinted at a mutually different position.
    Type: Grant
    Filed: August 10, 2001
    Date of Patent: May 4, 2004
    Assignee: TDK Corporation
    Inventor: Shigeru Shoji
  • Patent number: 6730858
    Abstract: A circuit board for mounting a part having a plurality of bumps by ultrasonic bonding. The circuit board includes a main body and a conductive layer provided on the main body. The conductive layer has a conductive pattern having at least one bonding area configured to correspond to the plurality of bumps of the part. The conductive layer has an isolated notch part located proximate the at least one bonding area.
    Type: Grant
    Filed: July 21, 1998
    Date of Patent: May 4, 2004
    Assignee: TDK Corporation
    Inventors: Masashi Gotoh, Jitsuo Kanazawa, Syuichiro Yamamoto, Kenji Honda
  • Patent number: 6729003
    Abstract: A process of producing a ceramic electronic component comprises external electrodes having first electrode layers containing at least a noble metal, cuprous oxide, and glass ingredient electrically connected to internal electrodes comprising a noble metal. As the ceramic electronic components, for example, a multi-layer ceramic capacitor, multi-layer varistor, multi-layer dielectric resonator, multi-layer piezoelectric element, etc. may be mentioned.
    Type: Grant
    Filed: November 8, 2001
    Date of Patent: May 4, 2004
    Assignee: TDK Corporation
    Inventors: Hideki Yokoyama, Takaya Ishigaki, Akira Sasaki, Shintarou Kon, Tetuji Maruno