Patents by Inventor Takashi Takahashi

Takashi Takahashi 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: 5438021
    Abstract: A multiple-chip semiconductor device of the present invention comprises a first and a second leadframes. The same package envelops a power semiconductor chip mounted on a power chip mounting area in the first leadframe and a control chip mounted on a control chip mounting area in the second leadframe. In the device, the second leadframe is made of metal material which is processed easier than the first leadframe, and/or is finished thinner than the first leadframe. Thus, the multiple-chip semiconductor device can effectively dissipate the heat producing in the power semiconductor chip.
    Type: Grant
    Filed: March 21, 1994
    Date of Patent: August 1, 1995
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Tomohide Tagawa, Takashi Takahashi, Takayoshi Kawasaki
  • Patent number: 5407443
    Abstract: A laser operation device for insertion into a region to be irradiated and which is optimally used as an introcular device to treat cataracts, glaucoma or the like. The device has a hand piece and a probe which is to be inserted into the region to be irradiated. A first fiber portion guides light from a laser light source to the hand piece, a second fiber portion connected with the first fiber portion at a connection surface thereof introduces light from the first fiber portion to the region to be irradiated. A first terminal formed to an end of the first fiber portion and a second terminal formed to an end of the second fiber portion are connected by a split sleeve, so that alignment between the first fiber portion and the second fiber portion is facilitated. Buffers around the first fiber and the second fiber protect the respective fibers from damage. Even if the second fiber portion were destroyed, safe and accurate incising operation can be applied to eye tissue or the like.
    Type: Grant
    Filed: December 6, 1993
    Date of Patent: April 18, 1995
    Assignee: Kabushiki Kaisha Topcon
    Inventors: Katuhiko Kobayashi, Takashi Takahashi
  • Patent number: 5399905
    Abstract: A resin sealed semiconductor device has a plurality of current-detecting resistors mounted and electrically connected in parallel on leads of a lead frame for detecting the current flowing in a semiconductor element mounted on the lead frame. Mounting n current-detecting resistors in parallel reduces the increase in resistance due to mounting to 1/nth the conventional value. Accordingly, changes in resistance values during mounting are minimized for accurate current measurement.
    Type: Grant
    Filed: January 13, 1994
    Date of Patent: March 21, 1995
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Ziro Honda, Takashi Takahashi
  • Patent number: 5359055
    Abstract: There are provided pregnane derivatives represented by formula ##STR1## wherein A.sup.1 represents a hydrogen atom or a hydroxyl group, A.sup.2 represents a substituent such as a hydroxyl group when A.sup.1 represents a hydrogen atom, or A.sup.2 represents a hydrogen atom when A.sup.1 represents a hydroxyl group, or A.sup.1 and A.sup.2 are combined together to form an oxo group; D.sup.1 represents a substituent such as a hydroxyl group, and D.sup.2 represents a hydrogen atom, or D.sup.1 and D.sup.2 are combined together to form an epoxy group or a single bond; D.sup.3, D.sup.5 and D.sup.7 each represents a hydrogen atom, D.sup.4 represents a hydroxyl group, and D.sup.6 represents a substituent such as a hydroxyl group, or D.sup.3 and D.sup.4 may be combined together to form an epoxy group or a single bond, or D.sup.4 and D.sup.5 may be combined together to form a single bond, or D.sup.5 and D.sup.6 may be combined together to form an epoxy group or a single bond, or D.sup.6 and D.sup.
    Type: Grant
    Filed: November 27, 1991
    Date of Patent: October 25, 1994
    Assignee: Kuraray Co., Ltd.
    Inventors: Jiro Tsuji, Takashi Takahashi, Masao Tsuji, Naoshi Nakagawa, Tetsuo Takigawa
  • Patent number: 5337169
    Abstract: A method of patterning an optical device for an optical IC whose purpose is to diffract a light beam incident on one surface of a device substrate to cause a light beam to emerge from another surface of the device. In this method, a layer of a substance of variable refractive index is formed on an optical substrate, coherent light is caused to irradiate the layer from the direction of the normal to the surface which will be the incidence side of the device when it is used or from the opposite side, and coherent light is caused to irradiate the layer from the direction of the normal to the surface which will be the emergence side of the device when it is used or from the opposite side to form an interference pattern on the layer that performs diffraction.
    Type: Grant
    Filed: February 23, 1993
    Date of Patent: August 9, 1994
    Assignee: Kabushiki Kaisha Topcon
    Inventors: Nobuo Hori, Yoshinobu Takano, Takashi Takahashi, Shigenori Nagano, Reiji Hashimoto
  • Patent number: 5334740
    Abstract: Cyclohexanetriol derivatives represented by the formula ##STR1## wherein R.sup.1, R.sup.2 and R.sup.3 are the same or different, and each denotes a hydrogen atom or a protecting group of a hydroxyl group,X denotes an oxygen atom, .dbd.CHCH.sub.2 OR.sup.4, .dbd.CHCHO or .dbd.CHCO.sub.2 R.sup.5, Y denotes a hydrogen atom and Z denotes --OR.sup.6, or Y and Z together form a single bond; or X and Z together form .dbd.NO--, .dbd.CHCH(OR.sup.7)O-- or .dbd.CHCO.sub.2 -- and Y is a hydrogen atom, R.sup.4 and R.sup.6 denote a hydrogen atom or a protecting group of a hydroxyl group respectively, R.sup.5 denotes a lower alkyl group, and R.sup.7 denotes a hydrogen atom or a lower alkyl group.Said derivatives are useful as synthetic intermediates of 1-hydroxyvitamin D derivatives.
    Type: Grant
    Filed: March 13, 1992
    Date of Patent: August 2, 1994
    Assignee: Kurary Co., Ltd.
    Inventors: Takashi Takahashi, Manzo Shiono
  • Patent number: 5319119
    Abstract: An oleophilic molybdenum compound comprising an aliphatic amine group and a heteropolyanion group containing at least one molybdenum atom as a polyatom is disclosed. The oleophilic molybdenum compound is a catalyst precursor capable of being changed, in the hydroconversion reaction system, to a catalyst having excellent catalytic activity in hydroconversion of a hydrocarbon feedstock to a hydrocarbon product having a decreased molecular weight. The oleophilic molybdenum compound is efficiently produced from an aliphatic amine and a heteropolyacid.
    Type: Grant
    Filed: March 11, 1992
    Date of Patent: June 7, 1994
    Assignee: Asahi Kasei Kogyo Kabushiki Kaisha
    Inventors: Tokitaka Kaneshima, Takashi Takahashi, Kazuhiro Matsubara
  • Patent number: 5313095
    Abstract: A multiple-chip semiconductor device of the present invention comprises a first and a second leadframes. The same package envelops a power semiconductor chip mounted on a power chip mounting area in the first leadframe and a control chip mounted on a control chip mounting area in the second leadframe. In the device, the second leadframe is made of metal material which is processed easier than the first leadframe, and/or is finished thinner than the first leadframe. Thus, the multiple-chip semiconductor device can effectively dissipate the heat producing in the power semiconductor chip.
    Type: Grant
    Filed: January 29, 1993
    Date of Patent: May 17, 1994
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Tomohide Tagawa, Takashi Takahashi, Takayoshi Kawakami
  • Patent number: 5310391
    Abstract: A transmission comprising a planetary gear mechanism wherein a plurality of planetary gears 6 are provided around a sun gear and meshed with the sun gear 5 and an internal gear 7 is provided outside the planetary gears and meshed with the planetary gears 6. The internal gear 7 consists of two split internal gears 7a, 7b divided by a plane perpendicular to its axial direction. Each of the plurality of planetary gears 6 consists of a large planetary gear 6a having a large diameter and small planetary gears 6b having small diameters and coaxially spline-coupled to the large planetary gear 6a in such a manner that the tooth portions thereof are positioned both sides of the large planetary gear 6a. The split internal gears 7a, 7b are meshed with the teeth of each small planetary gear 6b. The sun gear 5 is meshed with the large planetary gear 6a. An intermediate idle ring 11 is provided to each of the planetary gears 6 as a mechanism for equally distributing the load.
    Type: Grant
    Filed: May 15, 1992
    Date of Patent: May 10, 1994
    Inventor: Takashi Takahashi
  • Patent number: 5298841
    Abstract: A speed control apparatus in which for sampling features of a speed fluctuation and generating a speed fluctuation correcting signal, an arithmetic operation can be simplified and can be performed by an inexpensive arithmetic and operation unit, thus requiring no expensive arithmetic operation unit. The speed control apparatus is also capable of reducing torque ripples and speed fluctuations quickly even when the load of an object to be controlled is changed.
    Type: Grant
    Filed: April 18, 1991
    Date of Patent: March 29, 1994
    Assignee: Hitachi, Ltd.
    Inventors: Hiroshi Katayama, Fumio Tajima, Taizo Miyazaki, Shigeki Morinaga, Nobuyoshi Mutoh, Seiichi Narushima, Yuji Sato, Toshio Nakamoto, Takashi Takahashi, Toshio Osada
  • Patent number: 5266703
    Abstract: The present invention relates to novel optically active isoxazole derivatives represented by general formula: ##STR1## which are useful as intermediates for synthesis of prostaglandin and a process for producing the same as well as novel aldehyde compounds represented by general formula: ##STR2## which are intermediates for preparing the compounds [XI] described above and a process for preparation thereof. In the compounds shown by these formulae, R.sup.1 represents an alkyl group or a cycloalkyl group which may have an alkoxy group or a group shown by -Ra-A-B (wherein Ra is an alkyl group; A is a hetero atom or an single bond; and B is an aromatic or hetero ring which may have a substituent(s)); and R.sup.2 and R.sup.3, which may be the same or different, each represents an aralkyl group, a silyl group or an acyl group.
    Type: Grant
    Filed: June 30, 1992
    Date of Patent: November 30, 1993
    Assignee: Daiso Co., Ltd.
    Inventors: Takashi Takahashi, Kazuhiko Sakaguchi
  • Patent number: 5250715
    Abstract: The present invention provides an optically active 2-methylenepentane derivative represented by the general formula ##STR1## (wherein R.sup.1 is a protective group for hydroxyl, R.sup.3 is a protective group for hydroxyl, X is a halogen atom or R.sup.4 SO.sub.3 group (wherein R.sup.4 is an alkyl or an aryl), and the symbol * represents an asymmetric carbon atom).
    Type: Grant
    Filed: March 30, 1992
    Date of Patent: October 5, 1993
    Assignee: Daiso Co., Ltd.
    Inventors: Takashi Takahashi, Yoshikazu Takehira
  • Patent number: 5220074
    Abstract: The present invention relates to novel optically active isoxazole derivatives represented by general formula: ##STR1## which are useful as intermediates for synthesis of prostaglandin and a process for producing the same as well as novel aldehyde compounds represented by general formula: ##STR2## which are intermediates for preparing the compounds [XI] described above and a process for preparation thereof. In the compounds shown by these formulae, R.sup.1 represents an alkyl group or a cycloalkyl group which may have an alkoxy group or a group shown by -Ra-A-B (wherein Ra is an alkyl group; A is a hetero atom or an single bond; and B is an aromatic or hetero ring which may have a substituent(s)); and R.sup.2 and R.sup.3, which may be the same or different, each represents an aralkyl group, a silyl group or an acyl group.
    Type: Grant
    Filed: June 30, 1992
    Date of Patent: June 15, 1993
    Assignee: Daiso Co., Ltd.
    Inventors: Takashi Takahashi, Kazuhiko Sakaguchi
  • Patent number: 5218109
    Abstract: Steroid compounds of the following general formulas (I), (II) and (III) are provided: ##STR1## In the above formulas, R.sup.1 and R.sup.2 each is a hydrogen atom or a hydroxyl-protecting group, R is a group of the formula --CH.sub.2 --X (in which X is a substituent such as a hydroxyl group), a carboxyl group or a protected carboxyl group, A.sup.1 is an aryl group, a lower alkyl group or an aralkyl group, and Z.sup.1, Z.sup.2, Z.sup.3 and Z.sup.4 each is a hydrogen atom, a hydroxyl group or a protected hydroxyl group.The above steroid compounds are useful as intermediates for the synthesis of vitamin D.sub.3 derivatives having a hydroxyl group at the 1.alpha.-position.
    Type: Grant
    Filed: March 5, 1990
    Date of Patent: June 8, 1993
    Assignee: Kuraray Co., Ltd.
    Inventors: Jiro Tsuji, Takashi Takahashi, Masao Tsuji, Naoshi Nakagawa, Tetsuo Takigawa
  • Patent number: 5216187
    Abstract: The present invention provides an optically active 2-methylenepentane derivative represented by the general formula ##STR1## (wherein R.sup.1 is a protective group for hydroxyl, R.sup.3 is a protective group for hydroxyl, X is a halogen atom or R.sup.4 SO.sub.3 group (wherein R.sup.4 is an alkyl or an aryl), and the symbol * represents an asymmetric carbon atom).
    Type: Grant
    Filed: July 9, 1991
    Date of Patent: June 1, 1993
    Assignee: Daiso Co., Ltd.
    Inventors: Takashi Takahashi, Yoshikazu Takehira
  • Patent number: 5210201
    Abstract: The present invention relates to novel optically active isoxazole derivatives represented by general formula: ##STR1## which are useful as intermediates for synthesis of prostaglandin and a process for producing the same as well as novel aldehyde compounds represented by general formula: ##STR2## which are intermediates for preparing the compounds [XI] described above and a process for preparation thereof. In the compounds shown by these formulae, R.sup.1 represents an alkyl group or a cycloalkyl group which may have an alkoxy group or a group shown by --Ra--A--B (wherein Ra is an alkyl group; A is a hetero atom or an single bond; and B is an aromatic or hetero ring which may have a substituent(s)); and R.sup.2 and R.sup.3, which may be the same or different, each represents an aralkyl group, a silyl group or an acyl group.
    Type: Grant
    Filed: June 30, 1992
    Date of Patent: May 11, 1993
    Assignee: Daiso Co., Ltd.
    Inventors: Takashi Takahashi, Kazuhiko Sakaguchi
  • Patent number: 5200538
    Abstract: The present invention provides an optically active 2-methylenecyclopentanone derivative represented by the general formula ##STR1## (wherein R.sup.1 is a protective group for hydroxyl, and the symbol * represents as asymmetric carbon atom).
    Type: Grant
    Filed: May 27, 1992
    Date of Patent: April 6, 1993
    Assignee: Daiso Co., Ltd.
    Inventors: Takashi Takahashi, Yoshikazu Takehira
  • Patent number: 5198588
    Abstract: The present invention relates to novel optically active isoxazole derivatives represented by general formula: ##STR1## which are useful as intermediates for synthesis of prostaglandin and a process for producing the same as well as novel aldehyde compounds represented by general formula: ##STR2## which are intermediates for preparing the compounds [XI] described above and a process for preparation thereof. In the compounds shown by these formulae, R.sup.1 represents an alkyl group or a cycloalkyl group which may have an alkoxy group or a group shown by --Ra--A--B (wherein Ra is an alkyl group; A is a hetero atom or an single bond; and B is an aromatic or hetero ring which may have a substituent(s)); and R.sup.2 and R.sup.3, which may be the same or different, each represents an aralkyl group, a silyl group or an acyl group.
    Type: Grant
    Filed: January 23, 1991
    Date of Patent: March 30, 1993
    Assignee: Daiso Co., Ltd.
    Inventors: Takashi Takahashi, Kazuhiko Sakaguchi
  • Patent number: 5180844
    Abstract: The present invention provides an optically active 2-methylenecyclopentanone derivative represented by the general formula ##STR1## (wherein R.sup.1 is a protective group for hydroxyl, and the symbol * represents an asymmetric carbon atom).
    Type: Grant
    Filed: July 9, 1991
    Date of Patent: January 19, 1993
    Assignee: Daiso Co., Ltd.
    Inventors: Takashi Takahashi, Yoshikazu Takehira
  • Patent number: 5136066
    Abstract: The present invention provides a process for preparing an optically active cyclopentenone derivative represented by the formula ##STR1## by oxidizing an optically active cyclopentanone derivative represented by the formula ##STR2## with an oxidizing agent, and subsequently subjecting the oxidized compound to an elimination reaction. (In the above formulae, R.sup.1 is a protective group for hydroxyl, R.sup.5 is straight-chain or branched alkyl, alkenyl, alkynyl or alkylaryl having 5 to 22 carbon atoms and containing or not containing oxygen, sulfur or silicon, R.sup.6 is alkyl, aryl or heterocyclic group having or not having a substituent, Z is selenium or sulfur, and the symbol * represents an asymmetic carbon atom.
    Type: Grant
    Filed: July 9, 1991
    Date of Patent: August 4, 1992
    Assignee: Daiso Co., Ltd.
    Inventors: Takashi Takahashi, Yoshikazu Takehira