Patents by Inventor Takashi Hayakawa
Takashi Hayakawa 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: 5933726Abstract: A semiconductor device, such as a dynamic RAM, and method of making it. A number of stacked cell capacitors are placed at a prescribed spacing in an alignment direction on top of a p.sup.- -type silicon substrate (1). Each capacitor has a nearly perpendicular cylindrical lower electrode (cylindrical polysilicon layer (96)), a dielectric film (silicon nitride film (77)), and upper electrode (plate electrode (78) made of polysilicon). The spacing in the alignment direction is smaller than the inner diameter of the lower electrode.Type: GrantFiled: August 27, 1996Date of Patent: August 3, 1999Assignee: Texas Instruments IncorporatedInventors: Michio Nishimura, Kazuhiko Saitoh, Masayuki Yasuda, Takashi Hayakawa, Michio Tanaka, Yuji Ezaki, Katsuo Yuhara, Minoru Ohtsuka, Toshikazu Kumai, Songsu Cho, Toshiyuki Kaeriyama, Keizo Kawakita, Toshihiro Sekiguchi, Yoshitaka Tadaki, Jun Murata, Hideo Aoki, Akihiko Konno, Kiyomi Katsuyama, Takafumi Tokunaga, Yoshimi Torii
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Patent number: 5804479Abstract: The etch-back amount of a silicon oxide film of a memory array which is a higher altitude portion is increased when etching back and flattening the silicon oxide film by arranging a first-layer wiring on a BPSG film covering an upper electrode of an information-storing capacitative element only in a peripheral circuit but not arranging it in the memory array.Thus, a DRAM having a stacked capacitor structure is obtained such that the level difference between the memory array and peripheral circuit is decreased, and the formation of wiring and connection holes are easy.Type: GrantFiled: August 9, 1996Date of Patent: September 8, 1998Assignees: Hitachi, Ltd., Texas Instruments Inc.Inventors: Hideo Aoki, Jun Murata, Yoshitaka Tadaki, Toshihiro Sekiguchi, Keizo Kawakita, Takashi Hayakawa, Katsutoshi Matsunaga, Kazuhiko Saitoh, Michio Nishimura, Minoru Ohtsuka, Katsuo Yuhara, Michio Tanaka, Yuji Ezaki, Toshiyuki Kaeriyama, SongSu Cho
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Patent number: 5754925Abstract: An image forming apparatus includes: an image support medium; a charging member for charging the surface of the image support medium in contact with the surface of it; an exposure device for irradiating with light the surface of the image support medium charged by the charging member to form a static latent image; a developing device for supplying developer to the static latent image formed on the image support medium to develop the latent image and for removing the leftover developer on the image support medium; a transfer device for transferring the developer image, which has been developed on the image support medium by the developing device, to a member to be transferred; and a scraping member for scraping foreign matter such as dust and paper particles on the image support medium.Type: GrantFiled: September 27, 1996Date of Patent: May 19, 1998Assignee: Sharp Kabushiki KaishaInventors: Yuhi Yui, Katsumi Adachi, Takashi Hayakawa, Eiichi Kido, Koichi Moriyama, Toyokazu Mori
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Patent number: 5708929Abstract: In an image forming apparatus, when a transferred material exists in a transfer position between a photoreceptor drum and a transfer unit during an image forming operation, a transfer voltage, which has opposite polarity to that of a voltage applied to a brush charger and is used for transferring a developer image on the photoreceptor drum onto the transferred material is applied to the transfer unit. Meanwhile, when a transferred material does not exist in the transfer position during the image forming operation, a non-transfer voltage, which is lower than the transfer voltage, is applied to the transfer unit. As a result, defects on an image due to returning of a developer from the brush charger to the photoreceptor drum can be prevented from being generated.Type: GrantFiled: March 13, 1996Date of Patent: January 13, 1998Assignee: Sharp Kabushiki KaishaInventors: Katsumi Adachi, Takashi Hayakawa
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Patent number: 5689778Abstract: An image forming apparatus adopting a cleaningless process using contact-type charging means, includes developer scattering means which is located between the charging means and an exposure position in contact with the surface of an image carrier. For example, the developer scattering means is a conducting brush which scatters, catches and temporarily holds the residual toner on the image carrier. With this structure, even in an image forming apparatus adopting the cleaningless process using the contact-type charging means, the residual toner on the image carrier is scattered and caught by developer catching means before the residual toner reaches the exposure position. Thus, a lowering of the image quality which is caused if the residual toner is patterned by the charging means is prevented, thereby improving the image quality.Type: GrantFiled: November 13, 1995Date of Patent: November 18, 1997Assignee: Sharp Kabushiki KaishaInventors: Takashi Hayakawa, Katsumi Adachi
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Patent number: 5602659Abstract: A photoconductor coupled liquid crystal light valve comprising at least a pair of transparent electrode, a liquid crystal layer and a photoconductive layer showing blocking properties both sandwiched between said transparent electrodes, wherein said photoconductive layer includes a light absorbing layer and a blocking layer having a band gap wider than said light absorbing layer, both said light absorbing layer and said blocking layer being formed of non-alloy a-Si; and a method for manufacturing said photoconductor coupled light valve wherein said photoconductive layer is prepared with electron cyclotron resonance method.Type: GrantFiled: February 2, 1995Date of Patent: February 11, 1997Assignee: Sharp Kabushiki KaishaInventors: Katsumi Adachi, Takashi Hayakawa, Shiro Narikawa
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Patent number: 5592263Abstract: A charging device for use in an image forming apparatus is disclosed which charges an object to be charged by contacting a conductive charging member with the surface of the object and then applying a voltage across the charging member and the object,wherein at least a contact portion of the charging member comprises a conductive material having a hygroscopic degree of 0.2% or less.Type: GrantFiled: June 13, 1994Date of Patent: January 7, 1997Assignees: Gunze Limited, Sharp Kabushi KaishaInventors: Katsumi Adachi, Shiro Narikawa, Takashi Hayakawa, Yukihito Nishio, Hirofumi Yanagizawa, Takumi Sakamoto, Atsushi Okada
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Patent number: 5563691Abstract: An image-forming apparatus including a cleaning means for selectively removing foreign matters other than developer remaining on the surface of a photoconductor drum therefrom after a transferring process. The cleaning means is provided with a foreign-matter removing roller which comes into contact with the surface of the photoconductor drum. Foreign matters, which are charged by a transferring device to have a polarity reversed to that of the charged electric potential of toner through an electric field that is exerted between the surfaces of the roller and the photoconductor drum, are allowed to adhere to the surface of the foreign-matter removing roller. As for the surface of the foreign-matter removing roller, the surface electric potential of the foreign-matter removing roller is biased farther toward the polarity of the charged toner than the surface electric potential of the photoconductor drum at the contact portion between the photoconductor drum and the foreign-matter removing roller.Type: GrantFiled: June 5, 1995Date of Patent: October 8, 1996Assignee: Sharp Kabushiki KaishaInventors: Takashi Hayakawa, Katsumi Adachi, Yuhi Yui
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Patent number: 5555079Abstract: In an image forming apparatus including a charging element, a charged element, a developing element, and a cleaning element the dimensions of those elements satisfy either or both of the following relations:C+D<A<B-DC<E<A+Dwhere A denotes a longitudinal dimension of the charging element; B denotes an effective longitudinal width of a photoconductive layer coated range on the charged element; C denotes a developing width in the longitudinal direction of a developing element; D denotes a vibrating width of the charging member; and E denotes a longitudinal dimension of a cleaning element for the charged element.Type: GrantFiled: November 16, 1994Date of Patent: September 10, 1996Assignee: Sharp Kabushiki KaishaInventors: Katsumi Adachi, Takashi Hayakawa
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Patent number: 5426488Abstract: A charging member comprised of a conductive shaft and conductive fibers planted thereon is brought into contact with a charged member with a photoconductor provided on the surface thereof. The conductive shaft is applied with a combined voltage of d.c. voltage and a.c. voltage having a peak-peak value lower than two times the discharge starting threshold voltage that is determined by the surrounding atmosphere around the charged member. While the charging member and the charged member rotate at different surface velocity, the charged member is charged through the contact area in which impedance is low due to the influence of a.c. voltage, so that a stable surface potential close to the d.c. voltage may be charged onto the charged member. Further, it is effective that the frequency f of the a.c. voltage will be so set up as to suffice a relation: f>Vp/2R, where f is a frequency of the applied a.c. voltage, Vp(mm/s) is a moving velocity of the charged member, and R(mm) is a particle size of a developer used.Type: GrantFiled: October 14, 1993Date of Patent: June 20, 1995Assignee: Sharp Kabushiki KaishaInventors: Takashi Hayakawa, Kenji Tani, Katsumi Adachi
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Patent number: 5398102Abstract: The invention is directed to an apparatus for an electrophotographic process, equipped with a charging device of a contact type using a conductive roller or brush, and the charging device used therefor.Type: GrantFiled: April 21, 1993Date of Patent: March 14, 1995Assignee: Sharp Kabushiki KaishaInventors: Takasumi Wada, Kenji Tani, Takashi Hayakawa, Kouichi Irihara, Yukihito Nishio
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Patent number: 5338582Abstract: A photoconductor coupled liquid crystal light valve which comprises a pair of substrates opposite to each other, transparent electrodes arranged on each of the substrates, either one having a photoconductive layer and a carrier trapping layer formed over the transparent electrodes, a liquid crystal layer injected between the substrates and a voltage application means between the transparent electrodes.Type: GrantFiled: September 8, 1993Date of Patent: August 16, 1994Assignee: Sharp Kabushiki KaishaInventor: Takashi Hayakawa
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Patent number: 5324549Abstract: A method for fabricating a photoconductor coupled liquid crystal valve comprising the step of; deposing a transparent electrode on a transparent substrate; forming on said transparent electrode a photoconductive layer formed of amorphous silicon by the ECR; forming on said photoconductive layer an optical shielding layer formed of amorphous silicon by the ECR; forming on said optical shielding layer an optical reflection layer; forming an orientation film on said optical reflection layer; laminating on said orientation film a transparent substrate having a transparent electrode and another orientation film stoked thereon by the above method in such a manner that the two orientation films face each other with a spacer interposed therebetween; and disposing liquid crystals into said spacer.Type: GrantFiled: December 18, 1992Date of Patent: June 28, 1994Assignee: Sharp Kabushiki KaishaInventors: Takashi Hayakawa, Shiro Narikawa, Katsumi Adachi, Akitsugu Hatano
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Patent number: 5245059Abstract: 2,3,5-Trimethyl-p-benzoquinone is prepared advantageously by the catalytic oxidation of 2,3,5- or 2,3,6-trimethylphenol with hydrogen peroxide in an organic solvent, which is preferably acetic acid, in the presence of a catalyst which is a heteropolyacid of silicon or phosphorus as the center atom selected from phosphomolybdic acid, silicomolybdic acid, phosphotungstic acid and silicotungstic acid. The reaction proceeds rapidly even at room temperature to give the product in a high yield so that the method is industrially advantageous in addition to the advantages in respect of the inexpensiveness of the reactants and catalyst and absence of any noxious byproducts which may cause environmental pollution.Type: GrantFiled: March 3, 1989Date of Patent: September 14, 1993Assignee: Japan as represented by Director General of Agency of Industrial Science and TechnologyInventors: Masao Shimizu, Katsuomi Takehira, Takashi Hayakawa, Hideo Orita
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Patent number: 5239397Abstract: A photoconductor coupled liquid crystal light valve comprising a photoconductor layer, a liquid crystal layer and electrodes for applying voltage to the layers. The photoconductive layer is made of amorphous silicon containing hydrogen and/or halogen at more than 40 at%. The photoconductive layer preferably has a resistivity of between 10.sup.11 and 10.sup.12 ohm-cm and a photonconductivity of 10.sup.-8 and 10.sup.-6 cm.sup.2 /V. The photoconductive layer is preferably formed by electron cyclotron resonance.Type: GrantFiled: February 19, 1992Date of Patent: August 24, 1993Assignee: Sharp KabushikiInventors: Takashi Hayakawa, Shiro Narikawa, Kunio Ohashi
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Patent number: 5164281Abstract: A photosensitive body for electrophotography has as its principal constituent a photoconductive layer having amorphous silicon with hydrogen, a surface layer having a greater optical band gap than the photoconductive layer formed on a photoconductive base member, and an intermediate layer sandwiched therebetween.Type: GrantFiled: November 29, 1989Date of Patent: November 17, 1992Assignee: Sharp Kabushiki KaishaInventors: Takashi Hayakawa, Shoichi Nagata, Shiro Narukawa, Kazuki Wakita, Kunio Ohashi, Yoshikazu Fujiwara
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Patent number: 5126499Abstract: A process for the production of hydrocarbons having 2 or more carbon atoms by oxidative coupling of methane includes a step of contacting a feed gas containing methane with an oxide of metals having the following composition:MCo.sub.1-x Fe.sub.x O.sub.ywherein M stands for at least one alkaline earth metal x is a number greater than 0 but not greater than 1 and y is a number in the range of 2.5-3.5, at a temperature of 500.degree.-1000.degree. C.Type: GrantFiled: March 20, 1991Date of Patent: June 30, 1992Assignee: Director-General of Agency of Industrial Science and TechnologyInventors: Takashi Hayakawa, Katsuomi Takehira, Hideo Orita, Masao Shimizu, Yoshihito Watanabe
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Patent number: 5100749Abstract: An improved photosensitive member for electrophotography which comprises an intermediate layer, a photoconductive layer and a surface protecting layer each formed upwardly in this order on a conductive substrate, the photoconductive layer comprising a non-doped a-Si layer made of a amorphous silicon containing hydrogen and/or halogen of 40 at. % or more.Type: GrantFiled: February 19, 1991Date of Patent: March 31, 1992Assignee: Sharp Kabushiki KaishaInventors: Shiro Narikawa, Takashi Hayakawa, Kunio Ohashi
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Patent number: 5085968Abstract: A photosensitive member for electrophotography which comprises a conductive substrate and a photoconductive layer which is composed of an amorphous silicon layer and an amorphous silicon germanium layer containing a specific amount of hydrogen and/or halogen respectively, and being prepared by electron cyclotron resonance method respectively, which is useful for xerographic systems.Type: GrantFiled: December 3, 1990Date of Patent: February 4, 1992Assignee: Sharp Kabushiki KaishaInventors: Takashi Hayakawa, Shiro Narikawa, Kunio Ohashi
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Patent number: D334337Type: GrantFiled: August 13, 1990Date of Patent: March 30, 1993Assignee: Sumitomo Wiring Systems, Ltd.Inventors: Takayoshi Ito, Takashi Hayakawa