Patents Assigned to TDK Corporation
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Publication number: 20040062830Abstract: There is provided a mold component which makes it possible to mold a substrate for an optical recording medium which enables a functional layer having a uniform thickness to be formed thereon without using a resin-coating assisting member. A stamper holder holds a stamper thereon, and has a generally hollow cylindrical shape. An insertion hole formed through a central portion of the stamper has a diameter which is larger than an outer diameter of a cavity-side end of the stamper holder at a higher temperature of the holder than a normal temperature, and is slightly smaller than the outer diameter at the normal temperature of the holder. The cavity-side end inserted into the insertion hole at the higher temperature of the stamper is grasped by a rim of the insertion hole which is reduced in diameter at the normal temperature of the stamper.Type: ApplicationFiled: September 24, 2003Publication date: April 1, 2004Applicant: TDK CorporationInventors: Atsushi Koyama, Mamoru Usami, Kenji Yamaga, Mikio Domon, Kazuki Suzawa
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Publication number: 20040061986Abstract: In the thin-film magnetic head of the present invention, the length of each of a pinned layer and an antiferromagnetic layer in their contact area in the depth direction from a surface facing a medium is longer than the length of a free layer in the same direction. When the length of the pinned layer in the depth direction is set longer as such, the direction of magnetization of the pinned layer can be restrained from being tilted by disturbances. Also, the pinned layer and the antiferromagnetic layer have the same length in their contact area in the MR height direction, so that the pinned layer is in contact with the antiferromagnetic layer throughout its length in the MR height direction, thus raising the exchange coupling force, whereby the inclination in the direction of magnetization can be suppressed more effectively.Type: ApplicationFiled: September 2, 2003Publication date: April 1, 2004Applicant: TDK CORPORATIONInventors: Takeo Kagami, Noriaki Kasahara
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Publication number: 20040061988Abstract: The present invention provides a method of manufacturing a thin film magnetic head realizing both high precision in formation of a main magnetic pole layer and proper position of a flare point and capable of contributing to an improvement in recording performance from a manufacturing viewpoint. By performing a series of patterning processes using a buffer layer and a non-magnetic layer of which etching rate is low as a stopper layer, a main magnetic pole layer is formed. First, at the time of forming a front end portion, a precursor main magnetic pole layer (preparation layer of the main magnetic pole layer) is patterned by using the buffer layer as a mask, so that the front end portion is formed with high precision to have a small width as designed.Type: ApplicationFiled: September 30, 2003Publication date: April 1, 2004Applicants: TDK CORPORATION, SAE MAGNETICS (H.K.) LTD.Inventors: Naoto Matono, Norikazu Ota, Yuichi Watabe, Susumu Aoki, Yasuyuki Notsuke
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Publication number: 20040060165Abstract: The object of the invention is to provide a thin film magnetic head and a method of manufacturing the same, which allow the magnetic pole width to be precisely controlled and a sufficient overwrite performance to be attained even in a case where the magnetic pole width is microfabricated. The coupling position where the intermediate portion and the tip of the top pole are coupled each other is located closer to the air bearing surface than the throat height 0 position (TH0 position) which is the reference point for determining the throat height TH. The tip of the top pole defines the write track width on a recording medium. At least the portion of the intermediate portion from the TH0 position to the rear edge portion of the tip has a width wider than that of the tip. The intermediate portion suppresses saturation of the magnetic flux before flowing into the tip of the top pole.Type: ApplicationFiled: September 17, 2003Publication date: April 1, 2004Applicant: TDK CorporationInventor: Yoshitaka Sasaki
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Patent number: 6713581Abstract: Disclosed is a polymer material of low relative permittivity obtained through copolymerization of a monomer composition that contains, as monomers, a fumaric diester and an epoxy group-having (meth)acrylate. The polymer material bonds or adheres well to metal conductor layers, and, after crosslinked, it is patternable. In addition, it has good electric properties of low relative permittivity, low dielectric loss tangent and good electric insulation, and has good heat resistance.Type: GrantFiled: January 24, 2002Date of Patent: March 30, 2004Assignees: TDK Corporation, Dai-Ichi Kogyo Seiyaku Co., Ltd.Inventors: Shigeru Asami, Toshiaki Yamada, Teruaki Sugahara, Hiroshi Hotta
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Patent number: 6714103Abstract: A highly compact and easily fabricated band pass filter is disclosed. A band pass filter according to the present invention employs a first half-wave (&lgr;/2) resonator having a first open end on which an input terminal is formed and a second open end opposite to the first open end, a second half-wave (&lgr;/2) resonator having a third open end on which an output terminal is formed and a fourth open end opposite to the third open end, and an evanescent waveguide interposed between the second open end of the first resonator and the fourth open end of the second resonator. The first half-wave (&lgr;/2) resonator, the second half-wave (&lgr;/2) resonator, and the evanescent waveguide being single-unit. An air gap does not have to be formed by mounting components on a printed circuit board. Therefore, the overall size of the band pass filter can be miniaturized and fabrication of the band pass filter is simplified.Type: GrantFiled: November 2, 2001Date of Patent: March 30, 2004Assignee: TDK CorporationInventor: Arun Chandra Kundu
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Patent number: 6712984Abstract: Disclosed is a method of manufacturing a thin film magnetic head, which enables a magnetic pole portion to be formed with high precision in a short time. After forming a mask precursor pattern by patterning an alumina layer, the mask precursor pattern is subjected to an etching process of ion milling, thereby forming a first mask. The width of a portion in the first mask is narrower than the width of the minimum pattern which can be formed by a photolithography process. Consequently, by performing the etching process, the width of the portion of the first mask can be narrowed.Type: GrantFiled: March 21, 2001Date of Patent: March 30, 2004Assignee: TDK CorporationInventor: Yoshitaka Sasaki
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Patent number: 6714173Abstract: A screen display apparatus is capable of visually presenting to a viewer E a secondary image 30 (virtual image and/or a real image) as an “inclined” a primary image (subject) 10, and is vertically inclined with respect to said viewer at a position, which is different from a position of said primary image 10. This is realized through an action of a lens 20. With the “inclination, the viewer E views the secondary image 30 with a three-dimensional feeling. The “inclination” is effective when the upper part of the secondary image 30 is located farther from the viewer E than the lower part thereof, and when its angle &thgr; is within a range of 3° to 40°. Further, a screen display apparatus, a plurality of secondary images 30 (in the figures, virtual images 31 and 32) on a primary image 10 as a subject are formed by a microlens array 20 including convex microlenses 221 and concave microlenses 223.Type: GrantFiled: April 4, 2001Date of Patent: March 30, 2004Assignee: TDK CorporationInventor: Osamu Shinoura
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Patent number: 6713162Abstract: Using plural layers selected from among composite resin substrates having a fully high or low dielectric constant, composite resin substrates having a fully high magnetic permeability, and composite resin substrate layers having a fully high Q value, the invention provides a multilayer electronic part of small size having high performance and improved overall electrical characteristics. The multilayer electronic part includes constituent layers of at least two types formed of composite materials and a conductor layer formed on at least one composite material layer, wherein the conductor layer constructs a predetermined electric circuit.Type: GrantFiled: December 28, 2000Date of Patent: March 30, 2004Assignee: TDK CorporationInventors: Minoru Takaya, Toshikazu Endo
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Patent number: 6711929Abstract: A load applied to a slider by a suspension is adjusted as follows. First, the suspension is held while no external force to bend the suspension is applied to the suspension. Then, in this state, a position of a load beam is measured with a position measuring instrument. From the information on the position, a pitch angle of the load beam is determined, and conditions for laser light irradiation are determined from the pitch angle. Under the conditions thus determined, laser light is projected onto the front face or the rear face of a bent section of the load beam of the suspension.Type: GrantFiled: January 24, 2002Date of Patent: March 30, 2004Assignee: TDK CorporationInventors: Satoshi Yamaguchi, Ekihiro Nakae
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Patent number: 6713368Abstract: An etching mask is made of a metal such as Permalloy (NiFe) and has a T-shaped cross section made up of a vertical bar having width W1 and a lateral bar having width W2. Through ion beam etching with the etching mask, the region in the surface of a workpiece not covered with the mask is selectively removed by the ion beams applied thereto. In the mask the vertical bar has a region obstructed by the lateral bar and a redeposit portion. As a result, the region of the vertical bar near the interface between the workpiece and the vertical bar that substantially determines the pattern width does not change in width. Consequently, a pattern of the workpiece on which etching has been performed has the top width and bottom width substantially equal to width W1 of the vertical bar of the mask. The pattern is rectangular in cross section.Type: GrantFiled: August 6, 2001Date of Patent: March 30, 2004Assignee: TDK CorporationInventor: Koji Matsukuma
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Publication number: 20040058274Abstract: The present invention provides an optical recording medium that includes a recording layer composed mainly of an organic compound and can utilize blue-violet semiconductor laser light (390 to 420 nm in wavelength) as recording/reproducing laser light. The present invention also provides an optical recording/reproducing method using the optical recording medium. The optical recording medium 1 comprises at least a supporting substrate 2; a recording layer 3 on the supporting substrate 2, the recording layer 3 containing an organic compound as a major component; and a light-transmitting layer 5 on the recording layer 3, the light-transmitting layer 5 being capable of transmitting laser light with a wavelength of 390 to 420 nm for recording and reproducing information.Type: ApplicationFiled: September 9, 2003Publication date: March 25, 2004Applicant: TDK CORPORATIONInventors: Narutoshi Fukuzawa, Takashi Horai, Hiroshi Take
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Patent number: 6709321Abstract: A jig comprises: a main body; a retainer for retaining a block in which at least one row of sections to be sliders is aligned; a middle load application section coupled to a portion of the retainer located in the middle of the length thereof; end load application sections coupled to portions of the retainer near ends of the length thereof; middle couplers located between the middle load application section and each of the end load application sections, respectively, for coupling the main body to the retainer; and end couplers for coupling the main body to the ends of the length of the retainer. The length between the middle of the retainer and each of the ends thereof is greater than the length between the middle of the retainer and each of the end load application sections.Type: GrantFiled: December 12, 2000Date of Patent: March 23, 2004Assignee: TDK CorporationInventors: Kazuo Ishizaki, Makoto Hasegawa
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Patent number: 6710987Abstract: A magnetic tunnel junction device and method for making same is provided. A first ferromagnetic portion is provided. A barrier is provided on the first ferromagnetic portion. The barrier includes a first barrier portion on the first ferromagnetic portion. The first barrier portion is oxidized. After oxidizing, a second barrier portion is provided on the first barrier portion. The second barrier may be oxidized or annealed. A second ferromagnetic portion is provided on the barrier. The barrier of the resultant device has a reduced number of pinholes, minimizing the amount of the non-tunnel current, and an improved symmetry of electrical properties. This leads to advantages in performance characteristics and mass-production of the device.Type: GrantFiled: July 13, 2001Date of Patent: March 23, 2004Assignee: TDK CorporationInventors: Jijun Sun, Satoru Araki
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Patent number: 6709776Abstract: The invention has for its objects to provide a multilayer thin film comprising a ferroelectric thin film preferentially (001) oriented on an Si substrate, its fabrication process, and an electron device. To attain these object, the invention provides a multilayer thin film formed on a substrate by epitaxial growth, which comprises a buffer layer comprising an oxide and a ferroelectric thin film, with a metal thin film and an oxide thin film formed in this order between the buffer layer and the ferroelectric thin film, its fabrication process, and an electron device.Type: GrantFiled: April 27, 2001Date of Patent: March 23, 2004Assignee: TDK CorporationInventors: Takao Noguchi, Yoshihiko Yano, Hisatoshi Saitou, Hidenori Abe
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Patent number: 6709695Abstract: The invention aims to provide a method for preparing a composite substrate, which prevents an insulating layer surface from becoming rugged under the influence of an electrode layer, and eliminates a polishing step, whereby the composite substrate is easy to manufacture and ensures high display quality when applied to thin-film light emitting devices, the composite substrate and an thin-film EL device using the same. The object is attained by a method for preparing a composite substrate by successively applying an electrode paste and an insulator paste onto an electrically insulating substrate as thick films to form a composite substrate precursor having a green electrode layer and a green insulator layer laminated, subjecting the precursor to pressing treatment for smoothing its surface, and firing; the composite substrate and an EL device using the same.Type: GrantFiled: October 5, 2001Date of Patent: March 23, 2004Assignee: TDK CorporationInventors: Taku Takeishi, Katsuto Nagano, Suguru Takayama
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Publication number: 20040052194Abstract: An optical recording medium includes a substrate, a light transmission layer and a plurality of recording layers between the substrate and the light transmission layer and capable of recording data in the plurality of recording layers and reproducing data recorded in the plurality of recording layers by projecting a laser beam via the light transmission layer onto the plurality of recording layers, at least one recording layer other than a farthest recording layer from the light transmission layer among the plurality of recording layers including a first recording film containing Si as a primary component and a second recording film located in the vicinity of the first recording film and containing Cu as a primary component. In the thus constituted optical recording medium, it is possible to record data in a farthest recording layer from the light transmission layer and reproduce data from the farthest recording layer in a desired manner.Type: ApplicationFiled: July 3, 2003Publication date: March 18, 2004Applicant: TDK CorporationInventors: Hiroyasu Inoue, Hironori Kakiuchi, Masaki Aoshima, Koji Mishima
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Publication number: 20040053166Abstract: An optical recording medium according to the present invention includes a phase change recording layer where reversible phase changes between a crystal phase and an amorphous phase are used, wherein the recording layer includes at least Sb, Mn, and Te and, in a state corresponding to the crystal phase, has a structure where one diffracted ray is detected by X-ray diffraction as being present in respective ranges of spacings (Å) of 3.10±0.03, 2.25±0.03, and 2.15±0.03, in a range of between 3.13 and 2.12 spacing inclusive, with diffracted rays not being detected in other ranges within the 3.13 to 2.12 spacing range. Accordingly, the optical recording medium can be reliably crystallized even when the irradiation time of laser light is short, and also has superior thermal stability in an amorphous state.Type: ApplicationFiled: September 9, 2003Publication date: March 18, 2004Applicant: TDK CorporationInventors: Hiroshi Shingai, Hiroshi Chihara, Yoshitomo Tanaka, Masahiro Oishi, Hajime Utsunomiya
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Publication number: 20040051216Abstract: A method of producing a multilayer ceramic capacitor having internal electrode layers and dielectric layers with dielectric particles is disclosed. An average particle diameter of the dielectric particles, when measured parallel with the direction of the internal electrode layers, is larger than a thickness of the dielectric layer. A ratio (R/d) between the average particle diameter (R) and the thickness (d) of the dielectric layer is 1<R/d<3.Type: ApplicationFiled: August 5, 2003Publication date: March 18, 2004Applicant: TDK CORPORATIONInventors: Yuki Nakano, Shunichi Yuri, Mari Miyauchi, Daisuke Iwanaga
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Publication number: 20040051075Abstract: A magnetic ferrite composition including at least one of Mg, Ni, Cu, Zn, Mn, and Li and having a content of carbon within a predetermined range, for example, over 9.7 weight ppm to less than 96 weight ppm. The composition may be used as the magnetic core for an inductor, transformer, coil, etc. used for radios, televisions, communication devices, office automation equipment, switching power sources, and other electronic apparatuses or magnetic heads for video apparatuses or magnetic disk drives or other electronic components.Type: ApplicationFiled: September 12, 2003Publication date: March 18, 2004Applicant: TDK CorporationInventors: Takuya Aoki, Takeshi Nomura