Patents by Inventor Isamu Harada

Isamu Harada 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: 6159283
    Abstract: Apparatus for measuring the mechanical strength of a neck portion of a silicon seed crystal used for growing a silicon crystal by the Czochralski method includes a seed chuck for holding the seed crystal of a test sample and an end of a wire hung from an upper hook. A crystal holder which holds the other end part of the test sample from below is tied to a lower hook with another wire to support the holder. The apparatus includes means for pulling the hook at a given rate, and measuring means for continuously measuring tensile load. Such apparatus and the method thereby provide accurate measurement of mechanical strength of the neck portion of the silicon seed crystal with good precision and reproducibility. A single crystal ingot is grown under conditions affording good balance of productivity and safety.
    Type: Grant
    Filed: March 12, 1999
    Date of Patent: December 12, 2000
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Isamu Harada, Michiaki Oda, Masaru Toyoshima, Toshinari Murai, Eiichi Iino
  • Patent number: 5902395
    Abstract: In a pulling apparatus operated according to the multi-pulling method or CCZ method, granular silicon material is first fed to a feed pipe from a feeder so as to form stagnation of the granular silicon material in the feed pipe. The feeding of the granular silicon material from the feeder to the feed pipe is repeatedly commenced and stopped so as to maintain the stagnation of the granular silicon material. The feed rate of the granular silicon material from the feeder to the feed pipe is increased with time until the feed of the silicon material is completed. This prevents abrasion of a coating or lining provided on the inner surface of the feeder and also prevents damage of the feeder.
    Type: Grant
    Filed: February 3, 1997
    Date of Patent: May 11, 1999
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Naoki Nagai, Isamu Harada, Chihiro Tashiro, Michiaki Oda
  • Patent number: 5868835
    Abstract: A recharger system including a feeder and a feed conduit recharge polycrystalline silicon granules into a crucible after a run or operation of growing a single crystal silicon rod by the Czochralski method, thereby to prepare for a next run of crystal growing. The amount of holdup or backed-up supply of the silicon granules in the feed conduit is detected by a sensor provided on the feed conduit. A smooth and high-rate feed of the silicon granules is ensured by controlling the feed rate of the silicon granules from the feeder to the feed conduit and/or a descending velocity of the crucible by signals generated in the sensor as a function of the amount of the holdup or backed-up supply in the feed conduit.
    Type: Grant
    Filed: August 7, 1997
    Date of Patent: February 9, 1999
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Naoki Nagai, Michiaki Oda, Seiichiro Ohtsuka, Isamu Harada
  • Patent number: 5851286
    Abstract: A crystal pulling apparatus is disclosed which employs the Czochralski method. The crystal pulling apparatus is operated while a heater for heating a material melt in a crucible is controlled by the main controller of a main system. When maintenance of a heating state is disabled for some reason, a relay of a signal changeover circuit is switched so as to maintain the heating state under control of the backup controller of a backup system, thereby maintaining the material melt in a molten state. Thus, even when it becomes impossible for the main system to heat the material melt within the crucible, the material melt can be prevented from becoming solidified.
    Type: Grant
    Filed: December 11, 1996
    Date of Patent: December 22, 1998
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Atsushi Ozaki, Masahiko Urano, Isamu Harada, Tomohiro Kakegawa, Hideki Nakano
  • Patent number: 5733368
    Abstract: In a method of manufacturing a silicon monocrystal using a continuous Czochralski method, a silicon monocrystal is pulled from a silicon melt in a crucible while a silicon material is fed to the crucible. Supply of the silicon material is suspended until the temperature distribution of the silicon melt becomes stable after initiation of a straight body forming process, and the supply of the silicon material is commenced when the temperature distribution of the silicon melt has become stable. The feed rate of the silicon material is gradually increased until the feed rate becomes equal to a solidification rate of the silicon melt after the supply of the silicon material has been commenced. This method prevents the silicon monocrystal from becoming a polycrystal during the manufacture thereof.
    Type: Grant
    Filed: February 20, 1997
    Date of Patent: March 31, 1998
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Naoki Nagai, Isamu Harada, Michiaki Oda
  • Patent number: 5690733
    Abstract: A recharger system including a feeder and a feed conduit recharge polycrystalline silicon granules into a crucible after a run or operation of growing a single crystal silicon rod by the Czochralski method, thereby to prepare for a next run of crystal growing. The amount of holdup or backed-up supply of the silicon granules in the feed conduit is detected by a sensor provided on the feed conduit. A smooth and high-rate feed of the silicon granules is ensured by controlling the feed rate of the silicon granules from the feeder to the feed conduit and/or a descending velocity of the crucible by signals generated in the sensor as a function of the amount of the holdup or backed-up supply in the feed conduit.
    Type: Grant
    Filed: November 9, 1995
    Date of Patent: November 25, 1997
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Naoki Nagai, Michiaki Oda, Seiichiro Ohtsuka, Isamu Harada
  • Patent number: 5089239
    Abstract: A single crystal pulling apparatus having a wire which is used to pull a crystal is provided with a novel wire vibration prevention mechanism. The wire vibration prevention mechanism includes wire restriction devices which restrict the movement of the wire to movement in the vertical direction. The wire restriction devices may be mechanically driven in the horizontal direction in order to center the pulled crystal. The wire restriction devices are driven by pneumatic air cylinders. Use of the wire vibration prevention mechanism avoids the formation of deformed growth of the pulled crystal and thus reduces the occurrence of dislocations in the pulled crystal.
    Type: Grant
    Filed: April 17, 1990
    Date of Patent: February 18, 1992
    Assignee: Shin-Etsu Handotai Company Limited
    Inventors: Koji Mizuishi, Isamu Harada, Yasushi Nakamura, Michiaki Oda, Seiichiro Ohtsuka, Yoshihiro Hirano, Masahiko Urano
  • Patent number: 4180392
    Abstract: Organic fertilizers having a superior fertilizer response (or efficiency), and a higher nitrogen content but a lower water-insoluble type nitrogen content are prepared from spent liquors of sulfite pulp plants according to the method of the present invention. Said method comprises setting the solid matter concentration of said spent liquors in the reaction liquid consisting mainly of said spent liquors to 20-45% by weight and reacting therewith ammonia in an amount of 15-30 mol per 1 Kg of said solid matter, and oxygen or oxygen-containing gas at a reaction temperature of 90.degree.-120.degree. C. under a pressure of 4 Kg/cm.sup.2 or higher and lower than 10 Kg/cm.sup.2.
    Type: Grant
    Filed: March 10, 1978
    Date of Patent: December 25, 1979
    Assignees: Chisso Corporation, Sanyo Kokusaku Pulp Co Ltd
    Inventors: Hiroaki Ishibashi, Shizuo Tanoue, Masakuni Kudo, Isamu Harada
  • Patent number: 4050605
    Abstract: A high pressure resistant and water tight panel assembled tank consisting of unit panels, each unit panel is formed with a protrusion portion in the form of a pyramid or truncated pyramid progressively increasing its height toward a center of the square wall surface of the panel and has securing flanges at the peripheries of the panel. The unit panels consist of (a) bottom wall panels of which securing flanges are folded in a direction opposite to the extending direction of the protrusion portion and (b) side wall panels of which securing flanges are folded in a direction the same as that of the protrusion portion and having partially thicker portions, and the securing flanges of the wall panels embracing sealing seats therebetween are clamped together outside of the tank to form the assembled tank.
    Type: Grant
    Filed: May 27, 1976
    Date of Patent: September 27, 1977
    Assignee: Bridgestone Tire Company Limited
    Inventors: Hiroshi Wakana, Isamu Harada, Tsutomu Honma
  • Patent number: 4035060
    Abstract: An electro-optic device comprises a plurality of first electrodes provided on a top substrate and a second electrode provided on a bottom substrate, the first electrodes confronting the second electrode through electro-optical matter which will show electro-optical phenomena by the application of electric field, the first and second electrodes being connected through external impedance elements such as resistors or capacitors to a variable voltage source. In this electro-optic device, the electric field applied between the first and second electrodes are partially changed by various means, for instance, by making the areas of the first electrodes different, or by varying the values of the external impedance elements such as resistors or capacitors, as a result of which the electro-optical matter shows various electro-optical phenomena.
    Type: Grant
    Filed: November 13, 1975
    Date of Patent: July 12, 1977
    Assignee: Dainippon Printing Co., Ltd
    Inventors: Ichiro Tsunoda, Satoshi Takeuchi, Yoichiro Hirao, Takeo Suzuki, Yoshihiro Nishiue, Katsumasa Tadokoro, Toshimasa Fukagawa, Isamu Harada, Akira Misawa, Kazuo Watanabe
  • Patent number: 3944330
    Abstract: An electro-optic device comprises a plurality of first electrodes provided on a top substrate and a second electrode provided on a bottom substrate, the first electrodes confronting the second electrode through electro-optical matter which will show electro-optical phenomena by the application of electric field, the first and second electrodes being connected through electrical elements such as resistors or capacitors to a variable voltage source. In this electro-optic device, the electric field applied between the first and second electrodes are partially changed by various means, for instance, by making the areas of the first electrodes different, or by varying the values of the electrical elements such as resistors or capacitors, as a result of which the electro-optical matter shows various electro-optical phenomena.
    Type: Grant
    Filed: September 21, 1973
    Date of Patent: March 16, 1976
    Assignee: Dainippon Printing Co., Ltd.
    Inventors: Ichiro Tsunoda, Satoshi Takeuchi, Yoichiro Hirao, Takeo Suzuki, Yoshihiro Nishiue, Katsumasa Tadokoro, Toshimasa Fukagawa, Isamu Harada, Akira Misawa, Kazuo Watanabe