Patents by Inventor Hiroshi Koga

Hiroshi Koga 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: 5166638
    Abstract: An amplifier circuit configured to be selectively brought into an active condition or in an inactive condition by a control signal, comprises an input differential circuit stage having a pair of input terminals and one output node, and an output emitter follower stage having a driving NPN transistor having a base connected to the output node and a collector connected to a high voltage Vcc. An emitter of the driving NPN transistor is connected to an output terminal and a collector of an active load NPN transistor having an emitter connected to a low voltage Vss. A control circuit is connected to a base of the active load NPN transistor and is controlled by the control signal so as to turn on the active load NPN transistor in response to an active control signal and to turn off the active load NPN transistor in response to an inactive control signal.
    Type: Grant
    Filed: September 18, 1991
    Date of Patent: November 24, 1992
    Assignee: NEC Corporation
    Inventor: Hiroshi Koga
  • Patent number: 4816479
    Abstract: Xanthone derivatives of the formula (I): ##STR1## wherein W, X, Y and Z which may be the same or different represent a hydrogen atom, a halogen atom or a lower alkyl group having 1 to 4 carbon atoms; A is a hydrogen atom B is a hydroxymethyl group, a lower alkoxycarbonyl group having 1 to 4 carbon atoms, or a carboxyl group, provided that a --O--CH.sub.2 --B group is bonded to the 2- or 3-position of the xanthone ring and that there is no case in which X, Y, and Z are each a hydrogen atom concurrently; as well as intoxic salts thereof when B is a carboxyl group, and a process for preparing the same are disclosed.The compounds of formula (I) in accordance with the present invention are useful as diuretics having uricosuric activity and can be used in the treatment of edema or hypertension.
    Type: Grant
    Filed: December 2, 1986
    Date of Patent: March 28, 1989
    Assignee: Chugai Seiyaku Kabushiki Kaisha
    Inventors: Hiroshi Koga, Takashi Mori, Takashi Dan, Michitaka Akima
  • Patent number: 4791209
    Abstract: Novel furobenzisoxazole derivatives of the formula (I): ##STR1## (wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 which may be the same or different represent a hydrogen atom, a halogen atom, or a lower alkyl group having 1-4 carbon atoms; R.sub.5 is a hydroxymethyl group, a carboxyl group or a lower alkoxy carbonyl group having 1-3 carbon atoms; and X is a sulfur atom or a --CH.dbd.CH-- group), as well as intoxic salts thereof when R.sub.5 is a carboxyl group, and process for preparing the same are disclosed.The derivatives of formula (I) and nontoxic salts thereof have hypotensive, uricosuric and diuretic activities and hence ae useful as therapeutics for treating hyperuricemia, edema and hypertension.
    Type: Grant
    Filed: May 6, 1986
    Date of Patent: December 13, 1988
    Assignee: Chugai Seiyako Kabushiki Kaisha
    Inventors: Haruhiko Sato, Hiroshi Koga, Takashi Dan, Etsuro Onuma
  • Patent number: 4732906
    Abstract: Dioxolobenzisoxazole derivatives of the formula ##STR1## wherein R.sub.1 is a phenyl group which may be substituted with a halogen atom, a lower alkyl group having 1-3 carbon atoms or a lower haloalkyl group, or a thienyl group; R.sub.2 is a hydrogen atom or a lower alkyl group having 1-4 carbon atoms; and X and Y which may be the same or different represent a hydrogen atom or a halogen atom, as well as non-toxic salts thereof wherein R.sub.2 is a hydrogen atom, a process for preparing the same and a pharmaceutical composition containing the same are disclosed.The derivatives have diuretic and uricosuric activities and, therefore, are useful as a drug for treating hyperuricemia or hypertension.
    Type: Grant
    Filed: March 18, 1986
    Date of Patent: March 22, 1988
    Assignee: Chugai Seiyaki Kabushiki Kaisha
    Inventors: Hiroshi Koga, Takashi Dan, Haruhiko Sato, Etsuro Onuma
  • Patent number: 4661607
    Abstract: Xanthone derivatives of the formula (I): ##STR1## (wherein W, X, Y and Z which may be the same or different represent a hydrogen atom, a halogen atom or a lower alkyl group having 1 to 4 carbon atoms; A is hydrogen atom or together with Z forms a --CH.sub.2 -- group which binds to a phenyl carbon adjacent the phenyl carbon to which the oxygen of the group ##STR2## is attached to form a cyclic methylene chain; B is a hydroxymethyl group, a lower alkoxycarbonyl group having 1 to 4 carbon atoms, or a carboxyl group, provided that W is neither a hydrogen atom nor a 7-position methyl group when X, Y and Z are each a hydrogen atom, and A is a hydrogen atom and B is a carboxyl group or a lower alkoxycarbonyl group), as well as non-toxic salts thereof when B is a carboxyl group, and a process for preparing the same are disclosed.The compounds of formula (I) in accordance with the present invention are useful as diuretics having uricosuric activity and can be used in the treatment of edema or hypertension.
    Type: Grant
    Filed: September 12, 1985
    Date of Patent: April 28, 1987
    Assignee: Chugai Seiyaku Kabushiki Kaisha
    Inventors: Hiroshi Koga, Takashi Mori, Takashi Dan, Michitaka Akima
  • Patent number: 4641570
    Abstract: A swash plate type compressor having shoes provided with center holes on the slidable surfaces. The center hole provided with a bottom acts as a reservoir for lubricating oil and supplys the oil on the slidable surface of the shoe, which slides against the swash plate. There can be a second ring groove concentric to the center hole, or annexed grooves which are stretching outward radially from the center hole. The center hole also prevents the center part from protruding outward by thermal expansion, which is caused by friction. The slidable surface of the shoe is preferably coated with a layer containing solid lubricant so as to smooth the sliding motions.
    Type: Grant
    Filed: April 29, 1986
    Date of Patent: February 10, 1987
    Assignees: Taiho Kogyo Kabushiki Kaisha, Kabushiki Kaisha Toyoda Jidoshokki Seisakusho
    Inventors: Kenichiro Futamura, Keiichiro Ohtsu, Tatsuhiko Fukuoka, Kenji Takenaka, Yoshio Itakura, Hiroshi Koga
  • Patent number: 4448962
    Abstract: This invention relates to new compounds of value as antibacterial agents. More particularly, it relates to quinoline carboxylic acid derivatives, the hydrates and the acid or alkali addition salts thereof.
    Type: Grant
    Filed: October 14, 1981
    Date of Patent: May 15, 1984
    Assignee: Kyorin Seiyaku Kabushiki Kaisha
    Inventors: Tsutomu Irikura, Seigo Suzue, Akira Ito, Hiroshi Koga
  • Patent number: 4429127
    Abstract: This invention relates to a new compound of value as antibacterial agent. More particularly, it relates to a quinoline carboxylic acid derivative and the acid addition salts thereof.
    Type: Grant
    Filed: February 17, 1982
    Date of Patent: January 31, 1984
    Assignee: Kyorin Pharmaceutical Co., Ltd.
    Inventors: Tsutomu Irikura, Hiroshi Koga, Akira Ito
  • Patent number: 4398029
    Abstract: This invention relates to new compounds of value as antibacterial agent. More particularly, it relates to quinoline carboxylic acid derivatives, the hydrates and the salts thereof.
    Type: Grant
    Filed: February 20, 1981
    Date of Patent: August 9, 1983
    Assignee: Kyorin Seiyaku Kabushiki Kaisha
    Inventors: Tsutomu Irikura, Hiroshi Koga, Satoshi Murayama