Patents by Inventor Yuji Ishikura
Yuji Ishikura 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: 8948638Abstract: An image forming apparatus includes a latent image carrier; a latent image writer to write a latent image on the latent image carrier; a developing unit including a toner carrier having first and second electrodes insulated via an insulator member and a voltage applying unit to apply voltages to the first and second electrodes having a potential difference to generate first electric fields to cause the toner to hop from the toner carrier to the latent image carrier to develop a toner image; and a transfer unit to transfer the developed toner image to a transferring member. When alternating voltages having a same phase and same amplitude are applied to the first and second electrodes to form second electric fields between the latent image carrier and the toner carrier, the toner is discharged from the toner carrier to the latent image carrier in a toner discharge mode.Type: GrantFiled: August 23, 2011Date of Patent: February 3, 2015Assignee: Ricoh Company, Ltd.Inventors: Yuji Ishikura, Yasuyuki Ishii, Hideki Kosugi, Tetsuro Hirota, Masaaki Yamada, Yoshiko Ogawa, Atsushi Kurokawa, Hideyasu Seki, Masanori Horike, Shin Kayahara
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Patent number: 8594540Abstract: A development device includes a toner carrier including first and second groups of electrodes, a toner supplier, and an electrical field generator. The electrical field generator includes a positive-phase pulse voltage generation circuit, a negative-phase pulse voltage generation circuit, a first DC power source for supplying a bias for setting a peak value of pulse voltages, a second DC power source to output a variable voltage having a polarity identical to a polarity of toner charge, a first diode having an anode connected to a lower potential side of the first DC power source and a cathode connected to an output terminal of the positive-phase pulse voltage generation circuit, and a second diode having an anode connected to the lower potential side of the first DC power source and a cathode connected to an output terminal of the negative-phase pulse voltage generation circuit.Type: GrantFiled: January 14, 2011Date of Patent: November 26, 2013Assignee: Ricoh Company, LimitedInventors: Tetsuro Hirota, Hideki Kosugi, Yoshiko Ogawa, Atsushi Kurokawa, Hideyasu Seki, Masaaki Yamada, Yuji Ishikura
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Patent number: 8588635Abstract: A development device includes a developer container, a rotary developer carrier that is disposed facing the latent image carrier and including multiple outer electrodes arranged in a circumferential direction of the developer carrier, an inner electrode electrically insulated from the multiple outer electrodes, an insulation layer disposed between the inner and outer electrodes, and a surface layer overlaying the outer electrodes and electrically insulating the multiple outer electrodes from each other, a bias power source to generate electrical fields that change with time by applying a first and second bias voltages to the inner and outer electrodes, respectively, an electrical field adjuster to regulate the electrical fields in accordance with a thickness of the surface layer of the developer carrier, and a controller.Type: GrantFiled: December 29, 2010Date of Patent: November 19, 2013Assignee: Ricoh Company, LimitedInventors: Yoshiko Ogawa, Yasuyuki Ishii, Hideki Kosugi, Masaaki Yamada, Atsushi Kurokawa, Yuji Ishikura
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Patent number: 8433211Abstract: A disclosed developing device includes a toner carrying member having electrodes, a toner supply unit supplying the toner to the toner carrying member, and a hopping electric field generator unit generating electric field to cause the toner hopping on the toner carrying member by applying a pulse voltage to the electrodes. The hopping electric field generator unit includes a pulse voltage generator circuit generating the pulse voltage, a first direct-current power source supplying bias to the pulse voltage generator circuit for regulating a peak value of the pulse voltage, and a second direct-current power source having a same polarity with a toner charging polarity, and outputting a variable voltage level. The hopping electric field generator unit controls the peak value of the pulse voltage by changing an output of the first power source and a mean thereof by changing an output of the second power source.Type: GrantFiled: September 10, 2010Date of Patent: April 30, 2013Assignee: Ricoh Company, Ltd.Inventors: Masanori Horike, Tetsuro Hirota, Atsushi Kurokawa, Hideki Kosugi, Masaaki Yamada, Yoshiko Ogawa, Yuji Ishikura
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Publication number: 20120057891Abstract: An image forming apparatus includes a latent image carrier; a latent image writer to write a latent image on the latent image carrier; a developing unit including a toner carrier having first and second electrodes insulated via an insulator member and a voltage applying unit to apply voltages to the first and second electrodes having a potential difference to generate first electric fields to cause the toner to hop from the toner carrier to the latent image carrier to develop a toner image; and a transfer unit to transfer the developed toner image to a transferring member. When alternating voltages having a same phase and same amplitude are applied to the first and second electrodes to form second electric fields between the latent image carrier and the toner carrier, the toner is discharged from the toner carrier to the latent image carrier in a toner discharge mode.Type: ApplicationFiled: August 23, 2011Publication date: March 8, 2012Inventors: Yuji ISHIKURA, Yasuyuki Ishii, Hideki Kosugi, Tetsuro Hirota, Masaaki Yamada, Yoshiko Ogawa, Atsushi Kurokawa, Hideyasu Seki, Masanori Horike, Shin Kayahara
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Publication number: 20110229232Abstract: A lubricant applying device includes: a solid lubricant; an applying member that applies lubricant powder scraped off from the solid lubricant to an application target; a holding member that holds the solid lubricant; a biasing unit that biases the holding member to bring the solid lubricant on the holding member into contact with the applying member; and a regulating unit that regulates, when a force of a direction orthogonal to an endless movement direction of the applying member is applied from the applying member to the solid lubricant at a frictional surface therebetween, movement of the solid lubricant and the holding member in the orthogonal direction.Type: ApplicationFiled: March 14, 2011Publication date: September 22, 2011Inventors: Takeshi Kojima, Masanori Kawasumi, Shuji Tanaka, Shin Kayahara, Takuya Suganuma, Hiroyuki Sugiyama, Yuji Ishikura
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Publication number: 20110182626Abstract: A development device includes a toner carrier including first and second groups of electrodes, a toner supplier, and an electrical field generator to generate an electrical field for causing toner to hop along the surface of the toner carrier. The electrical field generator includes a positive-phase pulse voltage generation circuit, a negative-phase pulse voltage generation circuit, a first DC power source for supplying a bias for setting a peak value of pulse voltages, a second DC power source to output a variable voltage having a polarity identical to a polarity of toner charge, a first diode having an anode and a cathode connected to a lower potential side of the positive-phase pulse voltage generation circuit and an output terminal thereof, and a second diode having an anode and a cathode connected to the lower potential side of the positive-phase pulse voltage generation circuit and an output terminal thereof.Type: ApplicationFiled: January 14, 2011Publication date: July 28, 2011Inventors: Tetsuro HIROTA, Hideki Kosugi, Yoshiko Ogawa, Atsushi Kurokawa, Hideyasu Seki, Masaaki Yamada, Yuji Ishikura
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Publication number: 20110164892Abstract: A development device includes a developer container, a rotary developer carrier that is disposed facing the latent image carrier and including multiple outer electrodes arranged in a circumferential direction of the developer carrier, an inner electrode electrically insulated from the multiple outer electrodes, an insulation layer disposed between the inner and outer electrodes, and a surface layer overlaying the outer electrodes and electrically insulating the multiple outer electrodes from each other, a bias power source to generate electrical fields that change with time by applying a first and second bias voltages to the inner and outer electrodes, respectively, an electrical field adjuster to regulate the electrical fields in accordance with a thickness of the surface layer of the developer carrier, and a controller.Type: ApplicationFiled: December 29, 2010Publication date: July 7, 2011Inventors: Yoshiko OGAWA, Yasuyuki ISHII, Hideki KOSUGI, Masaaki YAMADA, Atsushi KUROKAWA, Yuji ISHIKURA
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Publication number: 20110064432Abstract: A disclosed developing device includes a toner carrying member having electrodes, a toner supply unit supplying the toner to the toner carrying member, and a hopping electric field generator unit generating electric field to cause the toner hopping on the toner carrying member by applying a pulse voltage to the electrodes. The hopping electric field generator unit includes a pulse voltage generator circuit generating the pulse voltage, a first direct-current power source supplying bias to the pulse voltage generator circuit for regulating a peak value of the pulse voltage, and a second direct-current power source having a same polarity with a toner charging polarity, and outputting a variable voltage level. The hopping electric field generator unit controls the peak value of the pulse voltage by changing an output of the first power source and a mean thereof by changing an output of the second power source.Type: ApplicationFiled: September 10, 2010Publication date: March 17, 2011Inventors: Masanori Horike, Tetsuro Hirota, Atsushi Kurokawa, Hideki Kosugi, Masaaki Yamada, Yoshiko Ogawa, Yuji Ishikura
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Patent number: 4335251Abstract: The present invention relates to the phenyl-propionic acid ester derivative of the following formula: ##STR1## The compound obtained by the present invention possesses a high degree of analgetic, antipyretic and anti-inflammatory activity and causes little side effects on the gastro-intestinal tracts, when administered orally and topically, and it may be useful as an oral and topical analgesic, antipyretic and anti-inflammatory agent.Type: GrantFiled: August 5, 1980Date of Patent: June 15, 1982Assignee: Hisamitsu Pharmaceutical Co. Inc.Inventors: Kanji Noda, Akira Nakagawa, Yuji Ishikura, Hiroyuki Ide
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Patent number: 4150137Abstract: The present invention relates to phenylacetic acid ester derivatives of the following general formula: ##STR1## wherein, R is selected from the group consisting of lower alkyl (other than ethyl) and substituted lower alkyl, and R' may be a hydrogen or methyl.The compounds obtained by the present invention possess a high degree of analgetic ,antipyretic and anti-inflammatory activites and cause little side effects on the gastro-intestinal tracts, when administered orally and topically, and they may be useful as oral and topical analgetics, antipyretics and antiinflammatory agents.Type: GrantFiled: October 25, 1977Date of Patent: April 17, 1979Assignee: Hisamitsu Pharmaceutical Co. Inc.Inventors: Kanji Noda, Akira Nakagawa, Yuji Ishikura, Hiroyuki Ide