Patents by Inventor Takashi Obara
Takashi Obara 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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Patent number: 6754153Abstract: An exposure apparatus for an optical disc used for eliminating the vibrations in the propagating direction when a rotation mechanism rotates. The slider controller 40 and the spindle controller 41 of the exposure apparatus 1 are activated, and the then the optical disc begins to be rotated by an AC synchronized motor. Through a condensing device 9, laser beams emitted form the laser source 6 are irradiated on the optical disc for exposure. At this time, the optical disc is eccentrically chucked on the rotation mechanism, resulting a rotational vibration of the whole rotation mechanism. A measurer 17 is used for detecting a propagating component of the rotational vibration, and a vibrator controller 42 controls the vibrator 20 as the output of the measurer 17 approaches zero. Therefore, the vibration in the propagating direction of the base 2 is cancelled, and the propagation accuracy is increased and the exposure quality is enhanced.Type: GrantFiled: July 10, 2001Date of Patent: June 22, 2004Assignee: Ricoh Company, Ltd.Inventor: Takashi Obara
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Patent number: 6562705Abstract: A laser heating apparatus for forming an electrode on one surface of an Si chip provided on an Si wafer, thereby producing a semiconductor element, comprises a high vacuum chamber having a light transmission window, an XY table contained in the high vacuum chamber for mounting the Si wafer thereon, heater contained in the high vacuum chamber for heating and evaporating an impurity in a solid state, and laser beam applying means for applying a laser beam to the Si chip placed on the XY table from the outside of the high vacuum chamber through the light transmission window, thereby implanting the impurity into the Si in chip and activating the implanted impurity.Type: GrantFiled: October 26, 2000Date of Patent: May 13, 2003Assignee: Kabushiki Kaisha ToshibaInventors: Takashi Obara, Hideki Nozaki, Motoshige Kobayashi
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Publication number: 20030058542Abstract: A laser beam transmission apparatus comprises a light-incidence optical system (22) converging and focusing a laser beam emitted from a solid-state laser apparatus (1), and an optical fiber (8) which transmits the laser beam that has been converged and focused by the light-incidence optical system. The light-incidence optical system (22) has at least first and second lenses (13, 14) disposed on the same optical path. A first distance (a) between an output end of the solid-state laser apparatus and the first lens or a second distance (b) between the second lens and a light-incidence end of the optical fiber is freely set according to a relational formula based on a focal distance (f1, f2) of each of the first and second lenses.Type: ApplicationFiled: September 5, 2002Publication date: March 27, 2003Inventors: Yasuhiro Akiyama, Naotada Okada, Mitsuo Sasaki, Takashi Obara
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Publication number: 20020041549Abstract: An exposure apparatus for an optical disc used for eliminating the vibrations in the propagating direction when a rotation mechanism rotates. The slider controller 40 and the spindle controller 41 of the exposure apparatus 1 are activated, and the then the optical disc begins to be rotated by an AC synchronized motor. Through a condensing device 9, laser beams emitted form the laser source 6 are irradiated on the optical disc for exposure. At this time, the optical disc is eccentrically chucked on the rotation mechanism, resulting a rotational vibration of the whole rotation mechanism. A measurer 17 is used for detecting a propagating component of the rotational vibration, and a vibrator controller 42 controls the vibrator 20 as the output of the measurer 17 approaches zero. Therefore, the vibration in the propagating direction of the base 2 is cancelled, and the propagation accuracy is increased and the exposure quality is enhanced.Type: ApplicationFiled: July 10, 2001Publication date: April 11, 2002Inventor: Takashi Obara
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Publication number: 20010005325Abstract: A semiconductor memory device according to the invention comprises a first memory cell region, a second memory cell region, and a sense-amplifier row region disposed between the first and second memory cell regions, wherein the sense-amplifier row region has therein a plurality of transistor rows constituting a plurality of sense-amplifiers, at least one power-supply side sense-amplifier driver transistor disposed on the side f the first memory cell region of the plurality of transistor rows, and at least one ground side sense-amplifier driver transistor disposed on the side of the second memory cell region of the plurality of transistor rows.Type: ApplicationFiled: December 12, 2000Publication date: June 28, 2001Applicant: NEC CorporationInventors: Makoto Kitayama, Yukio Fukuzo, Takashi Obara, Yasuji Koshikawa, Toru Chonan, Yasushi Matsubara, Hideki Mitou
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Patent number: 6217680Abstract: A steel slab having a composition that comprises at most 0.008% by weight of C, at most 0.5% by weight of Si, at most 1.0% by weight of Mn, at most 0.15% by weight of P, at most 0.02% by weight of S, from 0.01 to 0.10% by weight of Al, at most 0.008% by weight of N, from 0.035 to 0.20% by weight of Ti, and from 0.001 to 0.015% by weight of Nb, with a balance of Fe and inevitable impurities, in which those C, S, N, Ti and Nb satisfy the following condition: 1.2(C/12+N/14+S/32)<(Ti/48+Nb/93), is subjected to rough hot-rolling to a reduction ratio of not lower than 85%, at a temperature falling between the Ar3 transformation point of the steel and 950° C., then to finishing hot-rolling to a reduction ratio of not lower than 65%, at a temperature falling between. 600° C. and the Ar3 transformation point of the steel, while being lubricated, to thereby have a mean shear strain of not larger than 0.06, then pickled, pre-annealed at a temperature falling between 700 and 920° C.Type: GrantFiled: March 15, 1999Date of Patent: April 17, 2001Assignee: Kawasaki Steel CorporationInventors: Yoshikazu Kawabata, Kaneharu Okuda, Kei Sakata, Takashi Obara, Atsushi Ogino
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Patent number: 6210496Abstract: A cold rolled steel sheet having high strength and high formability and having excellent crushing performance can include 0.05-0.40 mass % of C, 1.0-3.0 mass % of Si, 0.6-3.0 mass % of Mn, 0.02-1.5 mass % of Cr, 0.010-0.20 mass % of P and 0.01-0.3 mass % of Al, with the remainder consisting essentially of Fe. The steel sheet includes a ferrite major phase and a minor phase consisting of martensite, acicular ferrite and retained austenite. The cold rolled steel sheet can be used in automobiles.Type: GrantFiled: February 12, 1999Date of Patent: April 3, 2001Assignee: Kawasaki Steel CorporationInventors: Syusaku Takagi, Kazuya Miura, Osamu Furukimi, Kei Sakata, Takashi Obara
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Patent number: 6171412Abstract: Disclosed are bake-hardenable sheet steel with good anti-aging property and a method for producing it. While controlling its C, P, S and N contents, the chemical composition of the sheet steel is defined to comprise not larger than 1.0% of Si, not larger than 3.0% of Mn, from 0.01 to 0.20% of Al and from 0.001 to 0.2% of Ti, in terms of % by weight. The value A (=(AIQUENCH−AI)/AIQUENCH) of the sheet steel is defined to be not smaller than 0.4 and the value AIQUENCH thereof to be not smaller than 30; or the ratio of the mean misorientation, M (degree), to the mean grain size, G (&mgr;m), M/G, of the sheet steel is defined to be not smaller than 0.8. The steel may additionally contain from 0.001 to 0.2% of Nb and/or from 0.0001 to 0.0080% of B. While controlling its Si, Mn, S, Al and N contents, the chemical composition of a steel slab is defined to comprise from 0.005 to 0.02% of C, not larger than 0.05% of P and from 0.025 to 0.19% of Nb, with satisfying the condition of 0.Type: GrantFiled: November 25, 1998Date of Patent: January 9, 2001Assignee: Kawasaki Steel CorporationInventors: Saiji Matsuoka, Masahiko Morita, Osamu Furukimi, Takashi Obara, Tetsuya Kiyasu, Yoshio Yamazaki
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Patent number: 6103394Abstract: A thin steel sheet having excellent rectangular drawability is produced by completing roughing rolling of steel containing C: 0.02 wt % or less, Si: 0.5 wt % or less, Mn: 1.0 wt % or less, P: 0.15 wt % or less, S: 0.02 wt % or less, Al: 0.01 to 0.10 wt %, N: 0.008 wt % or less, at least one of Ti: 0.001 to 0.20 wt % and Nb: 0.001 to 0.15 wt %, the balance comprising Fe, and inevitable impurities, in the temperature region of 950.degree. C. to the Ar.sub.3 transformation temperature: performing finish rolling at a reduction of over 70% under lubrication in the temperature region of the Ar.sub.3 transformation temperature to 500.degree. C.; pickling the sheet; annealing the resultant hot rolled sheet under conditions which satisfy the equations (1) and (2) below:(T+273) (20+log t).gtoreq.2.50.times.10.sup.4 (1)745.ltoreq.T.ltoreq.920 (2)wherein T: hot rolled sheet annealing temperature (.degree. C.Type: GrantFiled: March 3, 1998Date of Patent: August 15, 2000Assignee: Kawasaki Steel CorporationInventors: Kaneharu Okuda, Yoshikazu Kawabata, Kei Sakata, Takaaki Hira, Atsushi Ogino, Takashi Obara
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Patent number: 6027581Abstract: Cold rolled steel sheet with excellent deep drawability and excellent anti-aging properties, and manufacturing method. The cold rolled steel sheet comprises about C: above 0.015 to 0.150 wt %, Si: 1.0 wt % or less, Mn: 0.01 to 1.50 wt %, P: 0.10 wt % or less, S: 0.003 to 0.050 wt %, Al: 0.001 to below 0.010 wt %, N: 0.0001 to 0.0050 wt %, Ti: 0.001 wt % or more and Ti(wt %)/[1.5.times.S(wt %)+3.4.times.N(wt %)].ltoreq.about 1.0 and B: about 0.0001 to 0.0050 wt %, during annealing, grain growth is improved; Ti is added to form a nitride and a sulfide to avoid precipitation of fine TiC; B is added to precipitate Boron precipitates (Fe.sub.2 B, Fex(C,B)y) in a cooling the hot rolled steel sheet and in cooling step during annealing after cold rolling; a spherical cementite is precipitated and grown in which the Boron series precipitate is a precipitation site.Type: GrantFiled: September 23, 1997Date of Patent: February 22, 2000Assignee: Kawasaki Steel CorporationInventors: Kazunori Osawa, Masahiko Morita, Osamu Furukimi, Takashi Obara
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Patent number: 5942051Abstract: In a non-oriented electromagnetic steel sheet including about 0.01 wt % or less of C, about 1.0 wt % or less of Si, Mn in a range of about 0.1 wt % to 1.5 wt %, Al in a range of about 0.2 wt % to 1.5 wt %; the steel sheet having a critical amount of about 2 to 80 ppm rare earth metal, and the quantities of Ti and Zr in the steel sheet being limited to about 15 ppm or less of Ti, and about 80 ppm or less of Zr. The sheet exhibits excellent magnetic characteristics, such as iron loss, even when punched and laminated sheets are stress relief annealed at a low temperature for a short period of time.Type: GrantFiled: September 26, 1997Date of Patent: August 24, 1999Assignee: Kawasaki Steel CorporationInventors: Minoru Takashima, Keiji Sato, Takashi Obara
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Patent number: 5853503Abstract: After a starting material of steel comprising C: 0.001-0.20 wt %, Si: 0.01-0.50 wt %, Mn: 0.05-2.0 wt %, P: not more than 0.05 wt %, S: not more than 0.05 wt %, sol.Al: 0.01-0.10 wt %, N: not more than 0.020 wt % and the balance being Fe and inevitable impurities is heated above AC.sub.3 point, rough rolling is completed within a temperature range of (Ar.sub.3 point+100.degree. C.)-(Ar.sub.3 point+50.degree. C.), and super-high pressure descaling is carried out under conditions satisfying a jetting pressure of not less than 25 kgf/cm.sup.2 and a liquid quantity density of not less than 0.002 liter/cm.sup.2, and subsequently finish rolling at a rolling reduction of not less than 80% above Ar.sub.3 point of a rolling completion temperature is started in 5 seconds and coiling is carried out below 700.degree. C., whereby hot rolled steel sheets having a surface roughness Ra of not more than 0.8 .mu.m and an average scale thickness of not more than 4 .mu.Type: GrantFiled: April 28, 1997Date of Patent: December 29, 1998Assignee: Kawasaki Steel CorporationInventors: Kazuhiro Seto, Kei Sakata, Osamu Furukimi, Takashi Obara
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Patent number: 5730810Abstract: In a non-oriented electromagnetic steel sheet including about 0.01 wt % or less of C, about 1.0 wt % or less of Si, Mn in a range of about 0.1 wt % to 1.5 wt %, Al in a range of about 0.2 wt % to 1.5 wt %; the steel sheet having a critical amount of about 2 to 80 ppm rare earth metal, and the quantities of Ti and Zr in the steel sheet being limited to about 15 ppm or less of Ti, and about 80 ppm or less of Zr. The sheet exhibits excellent magnetic characteristics, such as iron loss, even when punched and laminated sheets are stress relief annealed at a low temperature for a short period of time.Type: GrantFiled: April 18, 1995Date of Patent: March 24, 1998Assignee: Kawasaki Steel CorporationInventors: Minoru Takashima, Keiji Sato, Takashi Obara
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Patent number: 5676771Abstract: A non-oriented silicon steel sheet having a low core loss contains Si in an amount of about 2.5-5.0 wt % and S restricted to about 0.003 wt % or less and inclusions; the volume ratio of those inclusions having a particle size of about 4 .mu.m or higher to the total volume of inclusions is about 5-60%, and the volume ratio of inclusions having a particle size less than about 1 .mu.m to the total volume of inclusions is about 1-15%; when the sheet contains Mn in an amount of about 0.4-1.5%, and the volume ratio of particles less than 1 .mu.m is about 1-5%, the silicon steel sheet also has a low rotation core loss.The method of manufacturing comprises controlling the change of a cooling speed to about 5.degree. C./s.sup.2 or less in the cooling process of such steel sheet in a finish annealing.Type: GrantFiled: September 5, 1996Date of Patent: October 14, 1997Assignee: Kawasaki Steel CorporationInventors: Koji Yano, Atsuhito Honda, Takashi Obara, Minoru Takashima
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Patent number: 5676770Abstract: This invention relates to a non-oriented electromagnetic steel sheet with low leakage flux for a compact transformer and a method for making the same. After stress relief annealing, the magnetic permeability .mu..sub.C of the sheet in the direction transverse to the sheet rolling direction is.mu..sub.C .gtoreq.about 2.5.times.10.sup.-3 (H/m)and magnetic permeability .mu..sub.D of the sheet in the direction 45.degree. to the sheet rolling direction is.mu..sub.D .gtoreq.about 1.5.times.10.sup.-3 (H/m).Type: GrantFiled: December 11, 1995Date of Patent: October 14, 1997Assignee: Kawasaki Steel CorporationInventors: Keiji Sato, Kouji Yano, Minoru Takashima, Masaki Kawano, Takashi Obara
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Patent number: 5648931Abstract: In a logic data latch apparatus including a clock signal input circuit for receiving a clock signal and at least two logic signal input circuits for receiving logic signals, a logic circuit is connected to the logic signal input circuits so that a logic operation is performed upon the logic signals. An output signal of the logic circuit is latched in a latch circuit in synchronization with the clock signal.Type: GrantFiled: June 27, 1995Date of Patent: July 15, 1997Assignee: NEC CorporationInventor: Takashi Obara
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Patent number: 5639315Abstract: A process is disclosed for the production of a non-oriented electromagnetic steel strip having its magnetic characteristics uniformly retained in the product coil. The process involves by full- or semi-processing, hot rolling a steel slab containing not more than about 0.03% by weight of C, not more than about 3% by weight of Si and not more than about 2% by weight of Al such that the equation [Si wt %]+3 [Al wt %]-6 [C wt %] is in the range of about 0 to 2; and cold rolling the hot rolled steel strip in a known manner, followed optionally by finish annealing and also optionally by skin-pass rolling. The coil is finish rolled at a peripheral roll speed between about 500 to 1,500 mpm at the final stand. The peripheral roll speed at the final finish rolling stand is also controlled within a range of no more than about 300 mpm. Hot rolling is completed at a temperature Tf (.degree. C.) in an alpha-phase temperature zone and not less than about {750+30 ([Si wt %]+3 [Al wt %]-6 [C wt %])}.Type: GrantFiled: December 15, 1995Date of Patent: June 17, 1997Assignee: Kawasaki Steel CorporationInventors: Minoru Takashima, Keiji Sato, Takashi Obara
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Patent number: 5469386Abstract: A semiconductor synchronous dynamic random access memory device is responsive to a clock signal and a clock enable signal for selectively carrying out internal sequences such as a read-out sequence, a write-in sequence and a self-refreshing sequence, and a signal input unit assigned to the clock enable signal has a complementary logic gate type signal input circuit enabled in a self-refreshing sequence for receiving the clock enable signal and a current-mirror type signal input circuit enabled in other sequences for receiving the clock enable signal so that the current consumption of the signal input unit is decreased during the self-refreshing sequence.Type: GrantFiled: August 25, 1994Date of Patent: November 21, 1995Assignee: NEC CorporationInventor: Takashi Obara
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Patent number: 5444667Abstract: A synchronous dynamic random access memory device latches external command signals for defining the internal sequence, and an input circuit produces an internal control signal from a system clock signal and a clock enable signal for latching the external command signals, wherein the input circuit maintains the internal control signal in an active level for a predetermined time period regardless of the duty ratio of the external clock signal so that a malfunction hardly takes place.Type: GrantFiled: March 31, 1994Date of Patent: August 22, 1995Assignee: NEC CorporationInventor: Takashi Obara
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Patent number: 5413640Abstract: A method of producing a non-oriented electromagnetic steel strip by subjecting a low-carbon steel slab to hot-rolling, cold rolling at a small reduction and first annealing. In order to improve magnetic flux density and surface appearance of the product, specific conditions are employed so as to coarsen the crystalline structure to obtain a controlled and moderate crystal grain size after the annealing. The slab is cold-rolled at a rolling reduction of about 5 to 15% and is subjected to first annealing by heating at a rate of about 3.degree. C./sec or higher and holding the strip for about 5 to 30 seconds at 850.degree. C. to the A.sub.3 transformation temperature of the steel, while controlling the crystal grain size to about 100 to 200 .mu.m after first annealing.Type: GrantFiled: March 29, 1993Date of Patent: May 9, 1995Assignee: Kawasaki Steel CorporationInventors: Masahiko Manabe, Kazumi Morita, Yoshinari Muro, Takahiro Kan, Yoshiaki Iida, Hideo Kobayashi, Takashi Obara