Patents by Inventor Shigeo Seki
Shigeo Seki 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: 5841371Abstract: An encoder signal generating device in which a light receiving element (1) is constituted by a one-chip planar type phototransistor array that has a plurality of light receiving portions (21). Thus, this encoder signal generating device needs no amplification circuit. Even when using this encoder signal generating device as a device of the multi-channel type, the size of the light receiving element (1) is reduced, in comparison with that of a conventional light receiving element. Moreover, a highly sensitive encoder signal generating device, which has good S/N characteristics, is obtained.Type: GrantFiled: February 28, 1997Date of Patent: November 24, 1998Assignee: Tamagawa Seiki Kabushiki KaishaInventor: Shigeo Seki
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Patent number: 5774068Abstract: A code plate has an m-bit signal track read out in parallel for providing the starting position of an AC servo motor for commencing rotation when power is first turned ON. An n-bit signal track accompanied by an incremental signal track is provided on the code plate with the n-bit track read out serially, converted to pure binary in parallel, and used once rotation of the servo motor commences to provide the initial absolute value of the encoder. To this n-bit initial value is added signals from the incremental track upon continued rotation of the code plate.Type: GrantFiled: November 20, 1995Date of Patent: June 30, 1998Assignee: Tamagawa Seiki Kabushiki KaishaInventor: Shigeo Seki
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Patent number: 5572199Abstract: An absolute signal detecting method and an absolute encoder according to the present invention load a n-bit positional signal (3) to a counting circuit (12) through rotating a code plate (1) at power ON, and can obtain an absolute encoder signal (12A) after this load through performing count up/down of the counting circuit (12) with an incremental signal (2).Type: GrantFiled: December 16, 1994Date of Patent: November 5, 1996Assignee: Tamagawa Seiki Kabushiki KaishaInventor: Shigeo Seki
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Patent number: 4357331Abstract: A 7.alpha.-methoxycephalosporin derivative represented by the formula (I): ##STR1## wherein R.sub.1 represents a heterocyclic ring or an --S-- heterocyclic ring; R.sub.2 represents a hydrogen atom, a carboxy group or a --COOR.sub.5 group wherein R.sub.5 represents a lower alkyl group, a dialkylamino-lower alkyl group or a ##STR2## group wherein R.sub.6 represents a lower alkyl group, a lower acyl group or a lower alkoxycarbonyl group and Y represents a hydrogen atom or a lower alkyl group; R.sub.3 represents a hydrogen atom, a carbamoyl group or a lower acyl group; R.sub.4 represents a hydrogen atom, a lower alkyl group, a dialkylamino-lower alkyl group or a ##STR3## group wherein R.sub.6 and Y are defined as above; A and B, which may be the same or different, each represents a straight chain or branched chain alkylene group having 1 to 5 carbon atoms; and x represents 0 or 1; or a pharmaceutically acceptable salt thereof and a process for producing the same.Type: GrantFiled: December 17, 1979Date of Patent: November 2, 1982Assignee: Meiji Seika Kaisha, Ltd.Inventors: Katsuyoshi Iwamatsu, Shigeharu Inoue, Keinosuke Miyauchi, Shinichi Kondo, Shigeo Seki, Yujiro Yamada
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Patent number: 4357465Abstract: New routes are provided for the synthesis of 3',4'-dideoxykanamycin B which is effective in inhibiting kanamycin-resistant organisms from kanamycin B through new intermediate, of which a fundamental process comprises a new reaction of a 3',4'-epoxy derivative of amino- and hydroxyl-protected kanamycin B with a xanthate to form a corresponding 3',4'-dideoxy-3'-eno derivative followed by removal of the amino- and hydroxyl-protecting groups thereof and by hydrogenation of the resulting 3',4'-dideoxy-3'-eno-kanamycin B. A 3',4'-episulfide derivative corresponding to the 3',4'-epoxy derivative which is formed as second product in the reaction of 3',4'-epoxy derivative with xanthate is also used as intermediate for the preparation of 3',4'-dideoxykanamycin B.Type: GrantFiled: September 15, 1980Date of Patent: November 2, 1982Assignee: Zaidan Hojin Biseibutsu Kagaku Kenkyu KaiInventors: Hamao Umezawa, Sumio Umezawa, Shigeo Seki, Shunzo Fukatsu, Shuntaro Yasuda
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Patent number: 4290972Abstract: 4-Amino-2-hydroxybutyric acid or 2,4-diaminobutyric acid may be readily produced by a new process comprising reacting a propionic acid compound containing a .beta.-carboxamido substituent (-CONH.sub.2) on the carbon atom at the 3-position and optionally containing hydroxyl substituent and protected or unprotected amino substituent on the .alpha.-carbon atom thereof, with an alkanoic acid anhydride in liquid pyridine to convert the carboxamido group into a nitrile group, with occasional acylation of a .alpha.-hydroxyl group, occasionally removing the alkanoyl group from the .alpha.-acyloxyl group of the resulting nitrile intermediate, and then reducing the resultant nitrile compound with hydrogen to convert the nitrile group into an aminomethyl group, and further optionally removing the residual amino-protecting group from the resultant 4-aminobutyric acid compound.Type: GrantFiled: November 9, 1979Date of Patent: September 22, 1981Assignee: Meiji Seika Kaisha, Ltd.Inventors: Toshio Yoneta, Seiji Shibahara, Shigeo Seki, Shunzo Fukatsu
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Patent number: 4258184Abstract: Novel cephalosporin derivatives having formulae (V) and (III): ##STR1## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.8 and A are defined as in the specification.Type: GrantFiled: March 13, 1979Date of Patent: March 24, 1981Assignee: Meiji Seika Kaisha Ltd.Inventors: Fumio Kai, Takashi Tsuruoka, Osamu Makabe, Shigeharu Inouye, Hitoshi Ikeda, Yuzo Kazuno, Shokichi Nakajima, Shigeo Seki, Taro Niida
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Patent number: 4256744Abstract: This invention relates to novel compounds of the general formula (I): ##STR1## wherein A represents ##STR2## in which B represents a ring-forming residue of a 5- or 6-membered carbon-containing heterocycling ring containing at least one nitrogen atom and which may further contain an oxygen atom in the ring, and R.sub.1 and R.sub.Type: GrantFiled: February 2, 1979Date of Patent: March 17, 1981Assignee: Meiji Seika Kaisha, Ltd.Inventors: Shigeo Seki, Yashuharu Sekizawa, Fumio Kai, Yukio Suzuki, Michiaki Iwata, Tetsuro Watanabe
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Patent number: 4225706Abstract: A novel ester of a cephem compound having a carboxyl group at the 4-position in the nucleus; a process for preparing the same by reacting a cephem carboxylic acid or its salt with a halogenide; and a method for removing the protective group for the carboxyl group in the nucleus of a cephem compound by contacting it with an alcohol, or with an organic solvent in the presence of a Lewis acid.Type: GrantFiled: April 21, 1978Date of Patent: September 30, 1980Assignee: Meiji Seika Kaisha Ltd.Inventors: Shigeo Seki, Ken Nishihata, Satoru Nakabayashi, Toshinori Saito, Hitoshi Ikeda, Nobuo Itoh, Shokichi Nakajima, Shunzo Fukatsu
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Patent number: 4195170Abstract: New routes are provided for the synthesis of 3',4'-dideoxykanamycin B which is effective in inhibiting kanamycin-resistant organisms from kanamycin B through new intermediate, of which a fundamental process comprises a new reaction of a 3',4'-epoxy derivative of amino- and hydroxyl-protected kanamycin B with a xanthate to form a corresponding 3',4'-dideoxy-3'-eno derivative followed by removal of the amino- and hydroxyl-protecting groups thereof and by hydrogenation of the resulting 3',4'-dideoxy-3'-eno-kanamycin B. A 3',4'-episulfide derivative corresponding to the 3',4'-epoxy derivative which is formed as second product in the reaction of 3',4'-epoxy derivative with xanthate is also used as intermediate for the preparation of 3',4'-dideoxykanamycin B.Type: GrantFiled: February 23, 1978Date of Patent: March 25, 1980Assignee: Zaidan Hojin Biseibutsu Kagaku Kenkyu KaiInventors: Hamao Umezawa, Sumio Umezawa, Shigeo Seki, Shunzo Fukatsu, Shuntaro Yasuda
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Patent number: 4188480Abstract: A 9,3"-di-acyl derivative of a macrolide antibiotic can be readily produced by reacting a macrolide antibiotic or an acyl derivative thereof with an organic acid halide, particularly an alkanoic acid halide, in a solvent and in the presence of a molecular sieve consisting of a synthetic zeolite and then de-acylating partially the resultant acylation products by a partial hydrolysis in an aqueous alcohol to give the 9,3"-di-acyl derivative of the macrolide antibiotic.Type: GrantFiled: August 10, 1978Date of Patent: February 12, 1980Assignee: Meiji Seika Kaisha, Ltd.Inventors: Takeshi Nakamura, Satoru Nakabayashi, Shunzo Fukatsu, Shigeo Seki
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Patent number: 4175185Abstract: A process for preparing a cephalosporanic acid derivative or a 7-acylaminocephalosporanic acid derivative which comprises subjecting an esterifying agent to reaction in liquid sulfur dioxide in the presence of a base with an N-protected-cephalosporin C to obtain a diester, subjecting the diester to reaction in an inert solvent with an iminohalide forming agent to produce an iminohalide, subjecting the iminohalide with a lower alcohol to produce an iminoether, subjecting the product produced, after subjecting the iminoether to reaction with a reactive derivative of an organic acid, to hydrolysis and further eliminating the ester group of the carboxylic acid.Type: GrantFiled: March 31, 1978Date of Patent: November 20, 1979Assignee: Meiji Seika Kaisha Ltd.Inventors: Shigeo Seki, Satoru Nakabayashi, Toshinori Saito, Shunzo Fukatsu, Shokichi Nakajima, Toshiyasu Ishimaru
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Patent number: 4159372Abstract: A process for preparing a cephalosporin ester which comprises subjecting an organic halide or an alcohol to reaction with a cephalosporin acid, a cephalosporin acid halide or a salt thereof in the presence of liquid sulfur dioxide.Type: GrantFiled: March 6, 1978Date of Patent: June 26, 1979Assignee: Meiji Seika Kaisha Ltd.Inventors: Shigeo Seki, Satoru Nakabayashi, Ken Nishihata, Nobuo Itoh, Toshinori Saito, Masahiro Onodera, Shunzo Fukatsu
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Patent number: 4141790Abstract: Compounds are provided having the general formula I: ##STR1## wherein X represents an hydroxyl group, an acetoxy group or a thiosulfuric acid residue. The formula I compounds are prepared from compounds of the general formula II: ##STR2## wherein R.sub.1 represents hydrogen, a lower alkanoyl group, an arylalkanoyl group, an alkoxycarbonyl group, a lower haloalkoxycarbonyl group, a substituted or unsubstituted aroyl group, a N-arylcarbamoyl group of a substituted or unsubstituted aryl group; R.sub.2 either represents hydrogen or, together with the ##STR3## group, represents a phthalimido group; and X represents an hydroxyl group, an acetoxy group or a thiosulfuric acid residue, or their metal salts or their salts with organic bases, by causing the culture of a cephalosporin C acylase-producing strain of a microorganism, especially a mold, fungus, or the secondary preparation therefrom, to act on the latter compounds II in the presence of an aqueous medium.Type: GrantFiled: May 12, 1977Date of Patent: February 27, 1979Assignee: Meiji Seika Kaisha Ltd.Inventors: Tomizo Niwa, Chuhei Nojiri, Hitoshi Goi, Shinji Miyado, Fumio Kai, Shigeo Seki, Yujiro Yamada, Taro Niida
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Patent number: 4128714Abstract: A novel ester of 7-acylamido-3-methyl-cepham-4-carboxylic acid derivative and a process for the preparation thereof which comprises reacting penicillin sulfoxide ester with the metal halide, and a novel 7-acylamido-3-methyl-cepham-4-carboxylic acid derivative and a process for the preparation thereof which comprises reacting penicillin sulfoxide ester with the metal halide and decomposing the resultant in a reductive atmosphere.Type: GrantFiled: February 2, 1976Date of Patent: December 5, 1978Assignee: Meiji Seika Kaisha Ltd.Inventors: Masao Koyama, Shigeo Seki
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Patent number: 4113944Abstract: A cephalosporin compound represented by the formula (I) or (I') ##STR1## wherein R.sup.1 represents a phenyl group, a 2-thienyl group or a phenoxy group; R.sup.2 represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms which may be substituted with a phenyl group, an alkoxy group having 1 to 4 carbon atoms or a halogen atom, or a phenyl group which may be substituted with one or two groups selected from the group consisting of a halogen atom, a nitro group, an alkyl group having 1 to 4 carbon atoms and an alkoxy group having 1 to 4 carbon atoms; R.sup.Type: GrantFiled: June 19, 1975Date of Patent: September 12, 1978Assignee: Meiji Seika Kaisha, Ltd.Inventors: Fumio Kai, Toshinori Saito, Shigeo Seki, Toyoaki Kawasaki
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Patent number: 4091202Abstract: As new semi-synthetic antibiotic derivative are provided N-methanesulfonic acid derivatives of 3',4'-dideoxykanamycin B which are less toxic than the parent antibiotic and have useful high antibacterial activity. They are produced by interacting 3',4'-dideoxykanamycin B, an aldehyde such as paraformaldehyde and sulfurous acid or an alkali metal sulfite reagent.Type: GrantFiled: September 16, 1976Date of Patent: May 23, 1978Assignee: Zaidan Hojin Biseibutsu Kagaku Kenkyu KaiInventors: Hamao Umezawa, Sumio Umezawa, Shunzo Fukatsu, Shigeo Seki, Masao Murase, Shuntaro Yasuda
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Patent number: 3998816Abstract: New and useful cephem compounds derived from cephalosporin C are provided by this invention, which are valuable as intermediate for the synthesis of another bacteriocidally active cephem derivatives and which are readily extractable from its aqueous solution by means of an organic solvent and enable the cephalosporin C content in the aqueous fermentation broth filtrate to be recovered at an improved yield. Cephalosporin C present in the fermentation broth may be converted into the cephem compounds of this invention by reacting with a substituted chloroformate compound within said filtrate, and the cephem compounds so formed may then be extracted therefrom with an organic solvent. The cephem compounds of this invention further may be converted into a 7-acylamidocephalosporanic acid or 7-aminocephalosporanic acid through some successive reactions.Type: GrantFiled: April 2, 1974Date of Patent: December 21, 1976Assignee: Meiji Seika Kaisha, Ltd.Inventors: Shigeo Seki, Toshiyasu Ishimaru
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Patent number: 3988326Abstract: A compound having the formula: ##EQU1## and a 7-amihocephalosporanic acid derivative having the formula: ##SPC1##Are reacted in a homogeneous aqueous solution of the reactants to prepare a reaction of the formula: ##SPC2##In the formulas, R may be H or other defined substituents such as carboxyl group; R.sub.1 is H, an alkyl of 1-4 carbons or other defined substitents; R.sub.2 is H or phenyl or when taken together with R.sub.1 form a defined cyclicradical; R.sub.3 is H or other defined substituents and M is an alkali metal cation, ammonium cation or H.Type: GrantFiled: February 13, 1975Date of Patent: October 26, 1976Assignee: Meiji Seika Kaisha, Ltd.Inventors: Shigeo Seki, Shingo Sugimoto, Shokichi Nakajima
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Patent number: 3963712Abstract: A novel ester of 7-acylamido-3-methyl-cepham-4-carboxylic acid derivative and a process for the preparation thereof which comprises reacting penicillin sulfoxide ester with the metal halide, and a novel 7-acylamido-3-methyl-cepham-4-carboxylic acid derivative and a process for the preparation thereof which comprises reacting penicillin sulfoxide ester with the metal halide and decomposing the resultant in a reductive atmosphere.Type: GrantFiled: April 11, 1973Date of Patent: June 15, 1976Assignee: Meiji Seika Kaisha, Ltd.Inventors: Masao Koyama, Shigeo Seki