Patents by Inventor Ryuichi Saito

Ryuichi Saito 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: 5929519
    Abstract: An inverter device includes plural modules, each module being formed by a series circuit having a parallel circuit of a switching device and a first diode, and a parallel circuit of a second switching device and a second diode, allowing a reduced size, high reliability, high frequency switching and low noise. Each of the semiconductor modules includes a plurality of switching device chips and at least one diode chip formed on a metal substrate. Electrode plates are provided in locations of the module adjacent to the switching device chips and the diode chips to facilitate connection of the electrodes of the respective chips to one another and to the outside of the module.
    Type: Grant
    Filed: November 26, 1997
    Date of Patent: July 27, 1999
    Assignee: Hitchi, Ltd.
    Inventors: Mutsuhiro Mori, Ryuichi Saito, Shin Kimura, Syuuji Saitoo, Kiyoshi Nakata, Akira Horie, Yoshihiko Koike, Shigeki Sekine
  • Patent number: 5925721
    Abstract: In a process for producing a vinylidene fluoride resin by polymerizing vinylidene fluoride or a mixture of vinylidene fluoride and a vinyl monomer copolymerizable with vinylidene fluoride, a portion of an iodide compound represented by the formula: X-R.sub.f -X wherein R.sub.f is a divalent organic group containing at least two divalent fluoroalkyl ether groups: and X's are independently an iodine atom or a fluorine atom, provided that at least one of the X's is an iodine atom; is added to start the polymerization, and the remainder of the iodide compound is further added dividedly at least twice in the course of the polymerization. This process enables to obtain a vinylidene fluoride resin having a viscosity-average molecular weight of 150,000 or more and also having a superior water repellency. This resin has good mechanical strength and release properties and also can be well processed into films.
    Type: Grant
    Filed: February 18, 1998
    Date of Patent: July 20, 1999
    Assignee: Shin-Etsu Chemical Co., Ltd.
    Inventors: Ryuichi Saito, Tadashi Amano
  • Patent number: 5868961
    Abstract: A silacyclohexane compound represented by the following general formula (I). ##STR1## In this formula, R denotes a linear-chain alkyl group with 1-10 carbon atoms, a branched-chain alkyl group with 3-8 carbon atoms, a mono- or di-fluoroalkyl group with 1-10 carbon atoms, an alkoxyalkyl group with 2-7 carbon atoms, or an alkenyl group with 2-8 carbon atoms. ##STR2## is trans-1-silacyclohexylene or trans-4-silacyclohexylene group whose silicon at position 1 or position 4 has a substitutional group(s) of H, F, Cl or CH.sub.3. X denotes a R, OR, CN, F, Cl, CF.sub.3, CF.sub.2 Cl, CHFCl, OCF.sub.3, OCHF.sub.2, OCF.sub.2 Cl, OCHFCl, --(O).sub.m --CY.sub.1 .dbd.CX.sub.1 X.sub.2 (m denotes 0 or 1, Y.sub.1 and X.sub.1 respectively denote H, F or Cl, and X.sub.2 denotes F or Cl) or --O--C.sub.r F.sub.s H.sub.2r+1-s is (r denotes an integral of 2 to 4 and s denotes an integral of 1 to 7) group. Y denotes H or F. Z denotes H or F.
    Type: Grant
    Filed: August 11, 1995
    Date of Patent: February 9, 1999
    Assignee: Shin-Etsu Chemical Co., Ltd.
    Inventors: Takaaki Shimizu, Tsutomu Ogihara, Takeshi Kinsho, Tatsushi Kaneko, Ryuichi Saito, Hideshi Kurihara
  • Patent number: 5866037
    Abstract: Liquid crystal compositions which can improve the low .DELTA.n (refractive index anisotropy) of conventional liquid crystal compositions containing a silacyclohexane compound and which retain a low viscosity and hence show no decrease in response speed. Liquid crystal compositions having a high .DELTA.n of 0.13 to 0.25, a low viscosity of 30 cp or less, a low threshold voltage and a high voltage holding ratio can be obtained by adding thereto, as a required component, a compound having both a silacyclohexane ring and a tolan structure, or a miture of a compound having a silacyclohexane ring and a compound having a tolan structure.
    Type: Grant
    Filed: March 31, 1997
    Date of Patent: February 2, 1999
    Assignee: Shin-Etsu Chemical Co., Ltd.
    Inventors: Takaaki Shimizu, Tsutomu Ogihara, Tatsushi Kaneko, Toshiaki Takahashi, Mutsuo Nakashima, Takeshi Kinsho, Ryuichi Saito, Hideshi Kurihara
  • Patent number: 5801936
    Abstract: An inverter device includes plural modules, each module being formed by a series circuit having a parallel circuit of a first switching device and a first diode, and a parallel circuit of a second switching device and a second diode, allowing a reduced size, high reliability, high frequency switching and low noise.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: September 1, 1998
    Assignee: Hitachi, Ltd.
    Inventors: Mutsuhiro Mori, Ryuichi Saito, Shin Kimura, Kiyoshi Nakata, Syuuji Saitoo, Akira Horie, Yoshihiko Koike, Shigeki Sekine
  • Patent number: 5731970
    Abstract: An inverter device includes plural modules, each module being formed by a series circuit having a parallel circuit of a first switching device and a first diode, and a parallel circuit of a second switching device and a second diode, allowing a reduced size, high reliability, high frequency switching and low noise. Each module forms one arm portion of the inverter. Lifetimes of the diodes and the switching devices are set in a manner to equalize losses in the inverter. Preferably, insulated gate bipolar transistors (IGBTs) formed by diffusion are used as the switching devices since the lifetimes of these devices can easily be adjusted to optimize design of the inverter.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: March 24, 1998
    Assignee: Hitachi, Ltd.
    Inventors: Mutsuhiro Mori, Ryuichi Saito, Shin Kimura, Syuuji Saitoo, Kiyoshi Nakata, Akira Horie, Yoshihiko Koike, Shigeki Sekine
  • Patent number: 5659059
    Abstract: A silacyclohexane compound represented by the following general formula (I). ##STR1## In this formula, R denotes a linear-chain alkyl group with a carbon number of 1-10, a mono- or di- fluoro-alkyl group with a carbon number of 1-10, a branched-chain alkyl group with a carbon number of 3-8, an alkoxyalkyl group with a carbon number of 2-7, or an alkenyl group with a carbon number of 2-8. ##STR2## denotes trans-1-sila-1,4-cyclohexylene or trans-4-sila-1,4-cyclohexylene group whose silicon at position 1 or position 4 has a substitutional group(s) of H, F, Cl or CH.sub.3. X denotes a CN, F, Cl, CF.sub.3, CF.sub.2 Cl, CHFCl, OCF.sub.3, OCHF.sub.2, OCF.sub.2 Cl, OCHFCl, R or OR group (R is the same as defined in the general formula (I)). Y.sub.2 and Z denote H or F, independently to each other. Y.sub.1 denotes H, F or Cl.
    Type: Grant
    Filed: October 31, 1994
    Date of Patent: August 19, 1997
    Assignee: Shin-Etsu Chemical Co., Ltd.
    Inventors: Tsutomu Ogihara, Takaaki Shimizu, Takeshi Kinsho, Tatsushi Kaneko, Ryuichi Saito, Hideshi Kurihara
  • Patent number: 5641431
    Abstract: A silacyclohexanone compound represented by the following general formula (I). ##STR1## wherein Ar denotes a phenyl group or a tolyl group. R denotes a tolyl group, a linear-chain alkyl group with a carbon number of 2-10, a mono- or di-fluoroalkyl group with a carbon number of 1-10, a branched-chain alkyl group with a carbon number of 3-8 or an alkoxyalkyl group with a carbon number of 2-7. Also, a method of manufacturing silacyclohexane-type liquid crystal compounds represented by the general formula (II) ##STR2## and the general formula (III) ##STR3## which are derived from this compound.
    Type: Grant
    Filed: March 23, 1995
    Date of Patent: June 24, 1997
    Assignee: Shin-Etsu Chemical Co., Ltd.
    Inventors: Takeshi Kinsho, Takaaki Shimizu, Tsutomu Ogihara, Ryuichi Saito, Kazuyuki Asakura, Mutsuo Nakashima
  • Patent number: 5629888
    Abstract: A semiconductor memory device has a plurality of memory cells in an array, into which the memory cells data is writable, and which can subsequently be read. Each memory cell has a switching element with one terminal connected to a bit line of the array another terminal connected to at least one ferroelectric capacitor, and a control terminal connected to a word line. The cell may then be operated to detect the change in polarization of the ferroelectric capacitor when a voltage is applied which is not sufficient to cause a change of state of the ferroelectric capacitor. Alternatively, a ferroelectric capacitor and a capacitor other than a ferroelectric capacitor is connected to the switching element. In a further alternative, a plurality of ferroelectric capacitors are connected to the switching element, so that different data are writable into each.
    Type: Grant
    Filed: January 18, 1994
    Date of Patent: May 13, 1997
    Assignee: Hitachi, Ltd.
    Inventors: Ryuichi Saito, Hidekatsu Onose, Yutaka Kobayashi, Michio Ohue
  • Patent number: 5621243
    Abstract: A high reliability electric power control semiconductor device with a prolonged product lifetime has been provided by successfully suppressing the metal support plate or the metal heat dissipation plate from warping due to the thermal stress during bonding so as to prevent the occurrences of cracks and gaps in the brazing fillers in the bonded layers between the metal heat dissipation plate or the metal support plate and the insulation plate in the semiconductor device comprising the semiconductor elements, metal heat dissipation plate, thermal stress buffer, insulation plate, and the metal support plate, wherein at least one of the metal heat dissipation plate and the metal support plate comprises a copper alloy of which a softening temperature at which a hot hardness of which becomes 1/2 of the hardness at the room temperature is 350.degree. C. or more.
    Type: Grant
    Filed: December 23, 1994
    Date of Patent: April 15, 1997
    Assignees: Hitachi, Ltd., Hitachi Haramachi Electronics Co., Ltd.
    Inventors: Noboru Baba, Hisanori Okamura, Masahiko Sakamoto, Hirosi Akiyama, Ryuichi Saito, Yoshihiko Koike, Makoto Kitano, Sigeki Sekine, Hideya Kokubun, Nobuya Koike
  • Patent number: 5585672
    Abstract: A semiconductor module having heat sink plates and an insulating plate laminated under the semiconductor chips, wherein the thickness of the support base plate is set to be 2.5 times in thickness of the insulating plate, which is the maximum thickness among the heat sink plates and the insulating plate laminated in the semiconductor module, so that the thermal fatigue lives of the solder layers are balanced, and the life of the whole semiconductor module can be prolonged.
    Type: Grant
    Filed: May 18, 1995
    Date of Patent: December 17, 1996
    Assignee: Hitachi, Ltd.
    Inventors: Yoshihiko Koike, Ryuichi Saito, Sigeki Sekine, Yuuji Wakisawa
  • Patent number: 5573705
    Abstract: A liquid crystal composition comprising a silacyclohexane compound represented by the following formula (I): ##STR1## wherein R and R' denote an alkyl group, a mono- or di-fluoroalkyl group, an alkoxyalkyl group or an alkenyl group; at least one of ##STR2## denotes a silacyclohexylene group whose silicon at positions 1 or 4 has a substitutional group of H, F, Cl of CH.sub.3, and the other denotes a silacyclohexylene group whose silicon at positions 1 or 4 has a substitutional group of H, F, Cl or CH.sub.3 or a cyclohexylene group; and 0-2 of the substitutional groups X on the aromatic rings denote F and the remaining X's denote H.
    Type: Grant
    Filed: December 23, 1994
    Date of Patent: November 12, 1996
    Assignee: Shin-Etsu Chemical Co., Ltd.
    Inventors: Tatsushi Kaneko, Takeshi Kinsho, Takaaki Shimizu, Tsutomu Ogihara, Ryuichi Saito, Hideshi Kurihara
  • Patent number: 5567350
    Abstract: A silacyclohexane compound of formula (I): ##STR1## wherein R denotes a linear-chain alkyl group, a mono- or di-fluoroalkyl group, a branched-chain alkyl group, an alkoxyalkyl group, or an alkenyl group: at least one of ##STR2## denotes a 1-sila-1,4-cyclohexylene or a 4-sila-1,4-cyclohexylene group whose silicon at position 1 or 4 is H, F, Cl or CH.sub.3, and the other denotes a 1,4-cyclohexylene group, a 1-sila-1,4-cyclohexylene or a 4-sila-1,4-cyclohexylene group whose silicon at position 1 or 4 is H F, Cl or CH.sub.3 ; X denotes a substitutional group at an equatorial position, specifically CN, an alkyl group with its end group replaced by a trifluoromethyl group, an alkoxy group, an alkanoyloxy group, an alkoxycarbonyl group, a linear-chain alkyl group, or an alkoxyalkyl group; Y denotes a group at an axial position, specifically H or CN when Y is connected to a carbon atom in said (B) group or H, F, Cl or CH.sub.3 when Y is connected to a silicon atom in said (B) group.
    Type: Grant
    Filed: February 3, 1995
    Date of Patent: October 22, 1996
    Assignee: Shin-Etsu Chemical Co., Ltd.
    Inventors: Takaaki Shimizu, Takeshi Kinsho, Tsutomu Ogihara, Tatsushi Kaneko, Ryuichi Saito, Hideshi Kurihara
  • Patent number: 5561440
    Abstract: A liquid crystal active matrix display device includes a first substrate having a thin film transistor formed thereon. A light-screening film 1 is located on the first substrate in a manner to be overlapped with an ITO. The display device includes a second substrate having a color filter and a light-screening film 2 formed thereon. The second substrate is opposed to the first substrate. The light-screening film 2 extends from the uncontrollable area by a certain value depending on a voltage from the external, resulting in improving a numerical aperture.
    Type: Grant
    Filed: August 7, 1991
    Date of Patent: October 1, 1996
    Assignees: Hitachi, Ltd., Hitachi Haramachi Semi-Conductor, Ltd.
    Inventors: Masaaki Kitajima, Makoto Tsumura, Yoshiro Mikami, Katsuyuki Funahata, Yoshiharu Nagae, Yoko Wakui, Ryuichi Saito, Makoto Matsui, Fumiaki Nemoto
  • Patent number: 5547606
    Abstract: A silacyclohexane compound represented by the following general formula (I). ##STR1## In this formula, R denotes hydrogen, a linear-chain alkyl group with a carbon number of 1-10, a branched-chain alkyl group with a carbon number of 3-8, an alkoxyalkyl group with a carbon number of 2-7, a fluoroalkyl group with a carbon number of 1-10 in which one or two hydrogen atoms are substituted by florine atom(s), or an alkenyl group with a carbon number of 2-8. For the groups ##STR2## at least one of these is a trans-1-sila-1,4-cyclohexylene or trans-4-sila-1,4-cyclohexylene group whose silicon at position 1 or position 4 has a substitutional group(s) of H, F, Cl or CH.sub.3, and the other denotes a trans-1,4-cyclohexylene group. X denotes a CN, F, Cl, CF.sub.3, CF.sub.2 Cl, CHFCl, OCF.sub.3, OCHF.sub.2, OCF.sub.2 Cl, OCHFCl, R or OR group (R is the same as defined earlier). Y denotes H or F. Z denotes H or F.
    Type: Grant
    Filed: October 13, 1994
    Date of Patent: August 20, 1996
    Assignee: Shin-Etsu Chemical Co., Ltd.
    Inventors: Takeshi Kinsho, Tatsushi Kaneko, Takaaki Shimizu, Tsutomu Ogihara, Ryuichi Saito, Hideshi Kurihara
  • Patent number: 5543539
    Abstract: There is provided a silacyclohexane compound and method of making same. The silacyclohexane compound has the following formula (1): ##STR1## wherein R denotes a linear-chain alkyl group with a carbon number of 1-10, a mono- or di-fluoroalkyl group with a carbon number of 1-10, a branched-chain alkyl group with a carbon number of 3-8, an alkoxyalkyl group with a carbon number of 2-7, or an alkenyl group with a carbon number of 2-8, ##STR2## denotes a trans-1-sila-1,4-cyclohexylene or a trans-4-sila-1,4-cyclohexylene group having silicon at positions 1 or 4 with substitutional group(s) of H, F, C1 or CH.sub.3 ; n denotes 0 or 1; L.sub.1 and L.sub.2 independently denote H.F, C1, CN or CH.sub.3 ; L.sub.3 denotes F; m denotes O, 1 or 2; and X denotes H, CN, F, C1, CF.sub.3, CC1F.sub.2, CHFC1, OCC1F.sub.2, OCHFC1, OCHF.sub.2, OCF.sub.3, R or OR group.
    Type: Grant
    Filed: February 14, 1995
    Date of Patent: August 6, 1996
    Assignee: Shin-Etsu Chemical Co., Ltd.
    Inventors: Takaaki Shimizu, Takeshi Kinsho, Tsutomu Ogihara, Tatsushi Kaneko, Ryuichi Saito, Hideshi Kurihara
  • Patent number: 5498737
    Abstract: A silacyclohexane compound represented by the following general formula (1): ##STR1## wherein R denotes a linear-chain alkyl group with a carbon number of 1-10, a mono- or di-fluoroalkyl group with a carbon number of 1-10, a branched-chain alkyl group with a carbon number of 3-8, an alkoxyalkyl group with a carbon number of 2-7, or an alkenyl group with a carbon number of 2-8, and at least one of ##STR2## denotes a trans-1-sila-1,4-cyclohexylene or a trans-4-sila-1,4-cyclohexylene group whose silicon at position 1 or position 4 has a substitutional group(s) of H, F, Cl or CH.sub.3 and the other is a trans-1,4-cyclohexylene group, X denotes a CN, F, F, Cl, CF.sub.3, OCF.sub.3, OCHF.sub.2, OCHFCl, CF.sub.2 Cl, OCF.sub.2 Cl, R or OR group, Z.sub.1 denotes H, F or Cl, and Z.sub.2 denotes H or F.
    Type: Grant
    Filed: January 25, 1995
    Date of Patent: March 12, 1996
    Assignee: Shin-Etsu Chemical Co., Ltd.
    Inventors: Tsutomu Ogihara, Takaaki Shimizu, Takeshi Kinsho, Tatsushi Kaneko, Ryuichi Saito, Hideshi Kurihara
  • Patent number: 5496501
    Abstract: A silacyclohexane compound represented by the following general formula (I). ##STR1## In this formula, R denotes a linear-chain alkyl group with a carbon number of 1-10, a mono- or di-fluoroalkyl group with a carbon number of 1-10, a branched-chain alkyl group with a carbon number of 3-8, an alkoxyalkyl group with a carbon number of 2-7, or an alkenyl group with a carbon number of 2-8. ##STR2## denotes a trans-1-silacyclohexylene or trans-4-silacyclohexylene group whose silicon at position 1 or position 4 has a substitutional group(s) of H, F, Cl or CH.sub.3. X denotes a CN, F, Cl, CF.sub.3, CF.sub.2 Cl, CHFCl, OCF.sub.3, OCHF.sub.2, OCF.sub.2 Cl, OCHFCl, R or OR group. Y denotes H or F. Z denotes H or F.
    Type: Grant
    Filed: December 5, 1994
    Date of Patent: March 5, 1996
    Assignee: Shin-Etsu Chemical Co., Ltd.
    Inventors: Takaaki Shimizu, Tsutomu Ogihara, Takeshi Kinsho, Tatsushi Kaneko, Ryuichi Saito, Hideshi Kurihara
  • Patent number: 5459655
    Abstract: An inverter device includes plural modules, each module being formed by a series circuit having a parallel circuit of a first switching device and a first diode, and a parallel circuit of a second switching device and a second diode, allowing a reduced size, high reliability, high frequency switching and low noise. Each module forms one arm portion of the inverter. Lifetimes of the diodes and the switching devices are set in a manner to equalize losses in the inverter. Preferably, insulated gate bipolar transistors (IGBTs) formed by diffusion are used as the switching devices since the lifetimes of these devices can easily be adjusted to optimize design of the inverter.
    Type: Grant
    Filed: September 21, 1992
    Date of Patent: October 17, 1995
    Assignee: Hitachi, Ltd.
    Inventors: Mutsuhiro Mori, Ryuichi Saito, Shin Kimura, Kiyoshi Nakata, Syuuji Saitoo, Akira Horie, Yoshihiko Koike, Shigeki Sekine
  • Patent number: 5454977
    Abstract: A silacyclohexane compound represented by the following general formula (I). ##STR1## R denotes hydrogen, a linear-chain alkyl group with a carbon number of 1-10, a branched-chain alkyl group with a carbon number of 3-8, an alkoxyalkyl group with a carbon number of 2-7, or an alkenyl group with a carbon number of 2-8. For ##STR2## at least one of these is trans-1-silacyclohexylene or trans-4-silacyclohexylene group whose silicon at position 1 or position 4 has a substitutional group(s) of H, F, Cl or CH.sub.3, and the other denotes trans-1,4-cyclohexylene group. X denotes a CN, F, Cl, CF.sub.3, CF.sub.2 Cl, CHFCl, OCF.sub.3, OCHF.sub.2, OCF.sub.2 Cl, OCHFCl, R or OR group.
    Type: Grant
    Filed: June 21, 1994
    Date of Patent: October 3, 1995
    Assignee: Shin-Etsu Chemical Co., Ltd.
    Inventors: Takaaki Shimizu, Tsutomu Ogihara, Takeshi Kinsho, Tatsushi Kaneko, Ryuichi Saito, Hideshi Kurihara