Patents by Inventor Yuko Hayama
Yuko Hayama 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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Publication number: 20210159494Abstract: The present invention relates to a liquid composition including particles and a solvent, wherein a diffusion coefficient of the liquid composition decreases in one step-shaped curve through a single inflection point as content of the particles increases, and wherein the content of the particles is greater than or equal to the content of the particles at the inflection point.Type: ApplicationFiled: November 20, 2020Publication date: May 27, 2021Inventors: Ryuji HIGASHI, Kohji MATSUOKA, Masahiro MASUZAWA, Yuko HAYAMA, Hideo YANAGITA
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Patent number: 9188929Abstract: A curl straightening method in an image apparatus including a fixing apparatus and a curl straightening apparatus is disclosed. The method includes calculating moisture content of a sheet before being supplied to the fixing apparatus; measuring a temperature of a heating unit and a pressurizing unit; calculating a temperature and moisture content of the sheet in the respective conveying sections; calculating a conveying time of the sheet in the respective conveying sections; calculating a residual strain of the sheet in the respective conveying sections from the calculated temperature and the moisture content of the sheet in the respective conveying sections, the calculated conveying time, and the stress relaxation characteristics of the sheet; calculating a final curl amount using the calculated residual strain of the sheet in the respective conveying sections; and controlling the curl straightening apparatus based on the final curl amount obtained.Type: GrantFiled: December 23, 2013Date of Patent: November 17, 2015Assignee: RICOH COMPANY, LTD.Inventors: Shunichi Oohara, Yuko Hayama
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Patent number: 9031492Abstract: An image forming apparatus includes: a curl correction device which corrects curl generated in a recording medium having passed through a fixing device; a temperature/humidity sensor unit which is installed in a conveying path between the fixing device and the curl correction device, and detects and outputs temperature and humidity near a surface of the recording medium; a calculation unit which calculates temperature and moisture content of the recording medium from the temperature and humidity output values output from the temperature/humidity sensor unit, and calculates curl correction efficiency of the curl correction device from the temperature and moisture content of the recording medium; a control value determination unit which determines a control value to perform a curl correction in the curl correction device, based on the curl correction efficiency calculated by the calculation unit; and a control unit which controls the curl correction device by the control value.Type: GrantFiled: January 29, 2013Date of Patent: May 12, 2015Assignee: Ricoh Company, LimitedInventors: Shunichi Oohara, Yuko Hayama
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Publication number: 20140234002Abstract: A curl straightening method in an image apparatus including a fixing apparatus and a curl straightening apparatus is disclosed. The method includes calculating moisture content of a sheet before being supplied to the fixing apparatus; measuring a temperature of a heating unit and a pressurizing unit; calculating a temperature and moisture content of the sheet in the respective conveying sections; calculating a conveying time of the sheet in the respective conveying sections; calculating a residual strain of the sheet in the respective conveying sections from the calculated temperature and the moisture content of the sheet in the respective conveying sections, the calculated conveying time, and the stress relaxation characteristics of the sheet; calculating a final curl amount using the calculated residual strain of the sheet in the respective conveying sections; and controlling the curl straightening apparatus based on the final curl amount obtained.Type: ApplicationFiled: December 23, 2013Publication date: August 21, 2014Inventors: Shunichi OOHARA, Yuko HAYAMA
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Publication number: 20130195534Abstract: An image forming apparatus includes: a curl correction device which corrects curl generated in a recording medium having passed through a fixing device; a temperature/humidity sensor unit which is installed in a conveying path between the fixing device and the curl correction device, and detects and outputs temperature and humidity near a surface of the recording medium; a calculation unit which calculates temperature and moisture content of the recording medium from the temperature and humidity output values output from the temperature/humidity sensor unit, and calculates curl correction efficiency of the curl correction device from the temperature and moisture content of the recording medium; a control value determination unit which determines a control value to perform a curl correction in the curl correction device, based on the curl correction efficiency calculated by the calculation unit; and a control unit which controls the curl correction device by the control value.Type: ApplicationFiled: January 29, 2013Publication date: August 1, 2013Inventors: Shunichi OOHARA, Yuko HAYAMA
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Patent number: 7490827Abstract: A sheet conveying apparatus, an automatic draft conveying apparatus, a paper feeding apparatus, and an image forming apparatus capable of preventing self-oscillation of a conveying roller. When rigidity of an oscillation system of the conveying roller is K [N/m], the distance between a supporting point of an arm and a section of the arm to which an axis of the conveying roller is attached is L [mm], and arm angle, which is formed between a sheet and a line segment connecting the supporting point of the arm to the section of the arm to which the axis of the conveying roller is attached on an assumed plane perpendicular to a direction of the axis of the conveying roller, is ? [deg], ??(Pse×K?0.5)×(1/L) is satisfied, where Pse=37500.Type: GrantFiled: June 27, 2006Date of Patent: February 17, 2009Assignee: Ricoh Company, Ltd.Inventors: Katsuhiko Miki, Osamu Takehira, Yuko Hayama
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Publication number: 20070002117Abstract: A sheet conveying apparatus, an automatic draft conveying apparatus, a paper feeding apparatus, and an image forming apparatus capable of preventing self-oscillation of a conveying roller. When rigidity of an oscillation system of the conveying roller is K [N/m], the distance between a supporting point of an arm and a section of the arm to which an axis of the conveying roller is attached is L [mm], and arm angle, which is formed between a sheet and a line segment connecting the supporting point of the arm to the section of the arm to which the axis of the conveying roller is attached on an assumed plane perpendicular to a direction of the axis of the conveying roller, is ?[deg], ??(Pse×K?0.5)×(1/L) is satisfied, where Pse=37500.Type: ApplicationFiled: June 27, 2006Publication date: January 4, 2007Inventors: Katsuhiko Miki, Osamu Takehira, Yuko Hayama
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Patent number: 5822667Abstract: A transfer separator comprises a transfer belt or other transfer mechanism for carrying and conveying a sheet to apply a toner image from an image carrier onto the sheet and separating the sheet from the image carrier. A bias application electrode applies a transfer bias to the transfer belt, wherein a relation of Lp.gtoreq.aV, and a=1 mm/KV is established when the minimum distance between the image carrier and surface of the bias application electrode is set to Lp (mm) and the maximum voltage applied to the bias application electrode is set to V (KV) . Preferably, the bias application electrode has a coated layer, and the difference in thickness resistance between the coated layer and the transfer belt is within two orders of magnitude. The hardness of the coated layer is preferably equal to or greater than the hardness of the transfer belt.Type: GrantFiled: July 2, 1996Date of Patent: October 13, 1998Assignee: Ricoh Company, Ltd.Inventors: Yuko Hayama, Hirokazu Ishii, Satoshi Takano, Akio Kutsuwada, Hakuti Mizuishi, Hiroshi Itoh, Itaku Matsuta
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Patent number: 5812919Abstract: In an image forming apparatus, a lubricant is fed to an image carrier on which a toner image is to be formed. An endless rotatable transfer member conveys a recording medium to which the toner image is to be transferred from the image carrier. The transfer member is capable of contacting the surface of the image carrier to which the lubricant has been applied. As a result, an adequate amount of lubricant is evenly applied to the transfer member to reduce the coefficient of friction of the surface of the transfer member, thereby enhancing the cleanability of the transfer member.Type: GrantFiled: February 9, 1996Date of Patent: September 22, 1998Assignee: Ricoh Company, Ltd.Inventors: Satoshi Takano, Itaru Matsuda, Yuko Hayama, Hirokazu Ishii, Akio Kutsuwada, Haruji Mizuishi, Hiroshi Itoh