Patents by Inventor Shin Murayama
Shin Murayama 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: 20240134300Abstract: Provided is a toner comprising a toner particle comprising a binder resin and a. silica fine particle, wherein a total content of a polyvalent metal elements in the toner particle is 0.10 to 2.50 ?mol/g, a number-average particle diameter of a primary particle of the silica fine particle is 40 to 500 nm, and in the DD/MAS measurement of solid 29Si-NMR of the silica fine particle, peak PD1 corresponding to a silicon atom represented by Sia in a structure represented by formula (1) and peak PD2 corresponding to a silicon atom represented by Sib in a structure represented by formula (2) are observed, and when an area of the peak PD1 is defined as SD1 and an area of the peak PD2 is defined as SD2, SD1 and SD2 satisfy: 1.2?(SD1+SD2)/SD1?10.0.Type: ApplicationFiled: October 2, 2023Publication date: April 25, 2024Inventors: HITOSHI SANO, SHIN KITAMURA, TORU TAKAHASHI, RYUICHIRO MATSUO, RYUJI MURAYAMA, TAKAKUNI KOBORI, YOSHIHIRO OGAWA
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Publication number: 20240069457Abstract: The toner contains binder resin-containing toner particles and silica fine particle S1, wherein the weight-average particle diameter of the toner is 4.0-15.0 ?m, both inclusive, peaks originating with the silica fine particle S1 are observed in 29 Si-NMR measurement of the silica fine particle S1, and, in the spectrum obtained by 29Si CP/MAS NMR or 29Si DD/MAS NMR, the peak area of a peak corresponding to the D1 unit structure in the silica fine particle S1, the peak area of a peak corresponding to the D2 unit structure in the silica fine particle S1, and the peak area of a peak corresponding to the Q unit structure in the silica fine particle S1 satisfy a prescribed relationship.Type: ApplicationFiled: October 25, 2023Publication date: February 29, 2024Inventors: RYUJI MURAYAMA, SHIN KITAMURA, TORU TAKAHASHI, DAISUKE TSUJIMOTO, RYUICHIRO MATSUO, HITOSHI SANO, NOBUYUKI FUJITA, SHUJI YAMADA, YUKA GUNJI, TAKAKUNI KOBORI, YOSHIHIRO OGAWA, ATSUHIKO OHMORI, HIROKI KAGAWA, KEISUKE ADACHI, TOMOKO SUGITA
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Patent number: 9348309Abstract: An image forming apparatus includes a latent image bearer, a charging roller, a first cleaner, a second cleaner, and a rotation controller. The latent image bearer bears a latent image on a surface thereof. The charging roller charges the latent image bearer. The first cleaner cleans the surface of the latent image bearer. The second cleaner cleans a surface of the charging roller. The rotation controller controls the latent image bearer to execute a set of backward rotation and first forward rotation at least once during a non-image formation time period, and either temporarily stop and start second forward rotation or continuously execute the second forward rotation by a rotation distance corresponding to at least one rotation of the charging roller.Type: GrantFiled: February 10, 2015Date of Patent: May 24, 2016Assignee: Ricoh Company, Ltd.Inventors: Masanari Fujita, Yasuhide Matsuno, Shin Murayama, Shin Yamamoto, Shinichi Arasawa
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Patent number: 9298127Abstract: A developing device includes a developer bearer and a regulation member. The developer bearer bears developer on a surface thereof. The developer bearer is rotatable forward and in reverse. The regulation member is disposed in contact or non-contact with the surface of the developer bearer to regulate amount of the developer on the developer bearer. In a non-development period, when the developer bearer rotates in a direction of reverse rotation opposite to a direction of forward rotation in which the developer bearer rotates in a development period, the developer bearer stops a series of rotating operations after the developer bearer rotates in the direction of forward rotation as a last rotating operation. A total rotation amount of forward rotation is set to be greater than a total rotation amount of reverse rotation in the series of rotating operations.Type: GrantFiled: August 11, 2014Date of Patent: March 29, 2016Assignee: Ricoh Company, Ltd.Inventors: Yoshio Sakagawa, Shin Murayama, Yasuhide Matsuno
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Publication number: 20150234348Abstract: An image forming apparatus includes a latent image bearer, a charging roller, a first cleaner, a second cleaner, and a rotation controller. The latent image bearer bears a latent image on a surface thereof. The charging roller charges the latent image bearer. The first cleaner cleans the surface of the latent image bearer. The second cleaner cleans a surface of the charging roller. The rotation controller controls the latent image bearer to execute a set of backward rotation and first forward rotation at least once during a non-image formation time period, and either temporarily stop and start second forward rotation or continuously execute the second forward rotation by a rotation distance corresponding to at least one rotation of the charging roller.Type: ApplicationFiled: February 10, 2015Publication date: August 20, 2015Applicant: RICOH COMPANY, LTD.Inventors: Masanari FUJITA, Yasuhide MATSUNO, Shin MURAYAMA, Shin YAMAMOTO, Shinichi ARASAWA
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Patent number: 8977150Abstract: An image forming apparatus includes a rotatable photoconductor, a charging unit, an exposure unit to expose the photoconductor to reduce an electrical potential at the photoconductor, a developing unit to charge the toner held on a toner bearing member with friction and attract the toner to the exposed portion on the photoconductor by supplying a development voltage from a first power source and using an electrical potential difference between the toner bearing member and the photoconductor in the development area, a reverse development voltage controller to supply a reverse development voltage while a non-charged portion on the photoconductor passes the development area, and a developer reducing potential applier to supply a development restraining potential and an absolute value smaller than a target charging potential to the photoconductor while the reverse development voltage is supplied.Type: GrantFiled: November 15, 2012Date of Patent: March 10, 2015Assignee: Ricoh Company, Ltd.Inventors: Shin Yamamoto, Shin Murayama, Yoshio Sakagawa, Yuji Nagatomo
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Publication number: 20150055987Abstract: A developing device includes a developer bearer and a regulation member. The developer bearer bears developer on a surface thereof. The developer bearer is rotatable forward and in reverse. The regulation member is disposed in contact or non-contact with the surface of the developer bearer to regulate amount of the developer on the developer bearer. In a non-development period, when the developer bearer rotates in a direction of reverse rotation opposite to a direction of forward rotation in which the developer bearer rotates in a development period, the developer bearer stops a series of rotating operations after the developer bearer rotates in the direction of forward rotation as a last rotating operation. A total rotation amount of forward rotation is set to be greater than a total rotation amount of reverse rotation in the series of rotating operations.Type: ApplicationFiled: August 11, 2014Publication date: February 26, 2015Inventors: Yoshio SAKAGAWA, Shin Murayama, Yasuhide Matsuno
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Publication number: 20130142530Abstract: An image forming apparatus includes a rotatable photoconductor, a charging unit, an exposure unit to expose the photoconductor to reduce an electrical potential at the photoconductor, a developing unit to charge the toner held on a toner bearing member with friction and attract the toner to the exposed portion on the photoconductor by supplying a development voltage from a first power source and using an electrical potential difference between the toner bearing member and the photoconductor in the development area, a reverse development voltage controller to supply a reverse development voltage while a non-charged portion on the photoconductor passes the development area, and a developer reducing potential applier to supply a development restraining potential and an absolute value smaller than a target charging potential to the photoconductor while the reverse development voltage is supplied.Type: ApplicationFiled: November 15, 2012Publication date: June 6, 2013Inventors: Shin YAMAMOTO, Shin MURAYAMA, Yoshio SAKAGAWA, Yuji NAGATOMO
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Patent number: 8354164Abstract: A semiconductive member including an alkali metal salt having the formula (M)n.X in a surface layer thereof. M represents Na+, K+, or Li+; X represents Cl?, Br?, I?, F?, CH3COO?, CF3COO?, CH(COOH)CHCOO?, (CHCOO?)2, CH2(COOH)CH2COO?, (CH2COO?)2, (HOOC)Ar(COO?), Ar(COO?)2, (HOOC)2Ar(COO?), (HOOC)Ar(COO?)2, Ar(COO?)3, (HOOC)3Ar(COO?), (HOOC)2Ar(COO?)2, (HOOC)Ar(COO?)3, Ar(COO?)4, Ar—SO3?, Ar(SO3?)2, an oligomer or a polymer having an acrylic acid anion unit, or an oligomer or a polymer having an methacrylic acid anion unit; Ar represents a benzene ring, a naphthalene ring, or a biphenyl ring; and n is a numeral equivalent to the anionic valence of X.Type: GrantFiled: November 20, 2009Date of Patent: January 15, 2013Assignee: Ricoh Company, LimitedInventors: Chiyoshi Nozaki, Tetsumaru Fujita, Shintaro Yamada, Yuji Nagatomo, Shin Murayama, Manabu Hamada, Yoshimichi Ishikawa
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Patent number: 8185025Abstract: A developing device develops an electrostatic latent image formed on an image carrier with toner. The developing device includes a developer carrier, a developer supplying unit that supplies a developer on the developer carrier, a layer shaping member that shapes the developer supplied on the developer carrier into a thin layer, and an electric-field control member that is arranged downstream of a shaping nip formed between the developer carrier and the layer shaping member and that controls an intensity of an electric field generated between the developer carrier and the layer shaping member.Type: GrantFiled: July 21, 2009Date of Patent: May 22, 2012Assignee: Ricoh Company, LimitedInventors: Shintaro Yamada, Shin Murayama, Ryuji Inoue, Shuuichi Nakagawa, Kazushige Ohnishi
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Patent number: 8010023Abstract: A developing device for developing an electrostatic latent image on an image carrier by supplying a one-component developer to the image carrier. Good images can be obtained over long periods of time, without printing history becoming apparent on account of residual developer. The developing device has a developer carrier that is rotatable and disposed facing an image carrier; and a conductive developer supply and recovery member rotatably arranged so as to abut the developer carrier. The rotation direction of the conductive developer supply and recovery member is opposite to the rotation direction of the developer carrier at a position where the developer carrier and the conductive developer supply and recovery member abut each other. A contact pressure P between the developer carrier and the conductive developer supply and recovery member is set so as to satisfy the relationship 0 (kPa)<P<5.0 (kPa).Type: GrantFiled: July 24, 2008Date of Patent: August 30, 2011Assignee: Ricoh Company, Ltd.Inventors: Shin Murayama, Shuichi Nakagawa, Ryuji Inoue, Shintaro Yamada
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Patent number: 7945195Abstract: A developer regulating member capable of stably regulating the thickness of a developer even when used for a long time, while preventing the increase in the production cost, a developing device having the developer regulating member, an image forming apparatus having the developing device, a process cartridge, and a method of producing the developer regulating member. The average crystal particle diameter D [?m] of a plate-like member provided in a layer-thinning blade which functions as the developer regulating member and which abuts against a developing roller functioning as a developer carrier, and the curvature radius R [?m] of a bent portion satisfy the relationship of D?60.53×R×10?3?12.61.Type: GrantFiled: November 29, 2007Date of Patent: May 17, 2011Assignee: Ricoh Company, Ltd.Inventors: Ryuji Inoue, Shuuichi Nakagawa, Shin Murayama, Rumi Konishi, Shintaro Yamada, Kazushige Oonishi
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Patent number: 7890033Abstract: A developing device that prevents the formation of agglomerated masses of developing agent in the bottom of the developing agent housing chamber near the developing roller and the supply roller, and that maintains the fluidity of the developing agent in the bottom of the developing agent housing chamber, while minimizing any increase in size of the developing device.Type: GrantFiled: December 27, 2007Date of Patent: February 15, 2011Assignee: Ricoh Company, Ltd.Inventors: Shin Murayama, Shuuichi Nakagawa, Ryuji Inoue, Shintaro Yamada
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Patent number: 7865118Abstract: A developing device that can reliably supply toner from a toner supply roller to a developing roller and that does not generate scraping irregularities in the toner thin layer on the developing roller, and a process cartridge and an image forming apparatus having the same. The developing device has: a toner supply chamber; a developing roller provided in the toner supply chamber; a toner supply roller provided in the toner supply chamber for supplying toner to the developing roller; and a layer regulation member for forming the toner on the developing roller into a thin layer, and develops electrostatic latent images on an image carrier by applying bias voltage to the developing roller. An intermediate contact member is interposed between the developing roller and the toner supply roller.Type: GrantFiled: February 4, 2009Date of Patent: January 4, 2011Assignee: Ricoh Company, Ltd.Inventors: Shuuichi Nakagawa, Ryuji Inoue, Shin Murayama, Kazushige Ohnishi, Shintaro Yamada
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Patent number: 7835652Abstract: An image developing method is disclosed that is able to efficiently remove degraded toner on a developing agent carrier, prevent formation of abnormal images, ensure good image quality over time, and increase the service life of the device. The developing method includes a step of calculating an amount of consumption of the developing agent during image formation and an amount of consumption of the developing agent in a compulsory toner consumption mode under different calculation conditions between the image formation and the compulsory toner consumption mode. In the compulsory toner consumption mode, a developing bias different from a developing bias used during image formation is applied for a predetermined time period to discharge residual developing agent on a developing agent carrier to a latent image carrier.Type: GrantFiled: April 28, 2008Date of Patent: November 16, 2010Assignee: Ricoh Company, Ltd.Inventors: Rumi Konishi, Shuuichi Nakagawa, Ryuji Inoue, Shin Murayama, Kazushige Oonishi, Shintaro Yamada
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Patent number: 7831182Abstract: A disclosed developing device includes a developing roller; a supply roller that is in contact with the developing roller and configured to supply toner to the developing roller; a current measuring unit configured to measure an electric current that flows from the developing roller to the supply roller when the toner is supplied from the supply roller to the developing roller; and an error determining unit configured to detect a development error of the developing roller based on the electric current measured by the current measuring unit.Type: GrantFiled: April 8, 2008Date of Patent: November 9, 2010Assignee: Ricoh Company, Ltd.Inventors: Rumi Konishi, Kenji Asuwa, Yoshiko Ogawa, Shuuichi Nakagawa, Ryuji Inoue, Shin Murayama, Kazushige Oonishi, Shintaro Yamada
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Publication number: 20100150609Abstract: A semiconductive member including an alkali metal salt having the formula (M)n·X in a surface layer thereof. M represents Na+, K+, or Li+; X represents Cl?, Br?, I?, F?, CH3COO?, CF3COO?, CH(COOH)CHCOO?, (CHCOO?)2, CH2(COOH)CH2COO?, (CH2COO?)2, (HOOC)Ar(COO?), Ar(COO?)2, (HOOC)2Ar(COO?), (HOOC)Ar(COO?)2, Ar(COO?)3, (HOOC)3Ar(COO?), (HOOC)2Ar(COO?)2, (HOOC)Ar (COO?)3, Ar(COO?)4, Ar—SO3?, Ar(SO3?)2, an oligomer or a polymer having an acrylic acid anion unit, or an oligomer or a polymer having an methacrylic acid anion unit; Ar represents a benzene ring, a naphthalene ring, or a biphenyl ring; and n is a numeral equivalent to the anionic valence of X.Type: ApplicationFiled: November 20, 2009Publication date: June 17, 2010Inventors: Chiyoshi Nozaki, Tetsumaru Fujita, Shintaro Yamada, Yuji Nagatomo, Shin Murayama, Manabu Hamada, Yoshimichi Ishikawa
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Developing device including an advance impeding member and an image forming apparatus using the same
Patent number: 7680443Abstract: A developing device is provided with which the increase in torque of a supply roller, unevenness of image density, and wear to the supply roller caused by the formation of an aggregated block of toner in the gap between the supply roller and the opposing side wall of a supply developer holding chamber can be suppressed.Type: GrantFiled: February 9, 2007Date of Patent: March 16, 2010Assignee: Ricoh Company, Ltd.Inventors: Shin Murayama, Shuuichi Nakagawa, Ryuji Inoue, Shintaro Yamada -
Patent number: 7676184Abstract: A developing apparatus is disclosed that includes a developer carrier for carrying a developer used for developing a latent image, a developer supplying chamber having a developer supplying member for supplying the developer to the developer carrier by rotation, a developer storing chamber positioned above the developer supplying chamber for storing the developer and supplying the developer to the developer supplying chamber, and a partitioning member positioned between the developer supplying chamber and the developer storing chamber. The partitioning member has an opening through which the developer is supplied from the developer storing chamber to the developer supplying chamber. The developing apparatus includes a conveying member positioned above the partitioning member for conveying the developer in a substantially horizontal direction.Type: GrantFiled: November 30, 2007Date of Patent: March 9, 2010Assignee: Ricoh Company, Ltd.Inventors: Shin Murayama, Shuuichi Nakagawa, Ryuji Inoue, Yuji Nagatomo, Shintaro Yamada, Kazushige Oonishi, Hirobumi Ooyoshi, Tomofumi Yoshida
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Publication number: 20100028057Abstract: A developing device develops an electrostatic latent image formed on an image carrier with toner. The developing device includes a developer carrier, a developer supplying unit that supplies a developer on the developer carrier, a layer shaping member that shapes the developer supplied on the developer carrier into a thin layer, and an electric-field control member that is arranged downstream of a shaping nip formed between the developer carrier and the layer shaping member and that controls an intensity of an electric field generated between the developer carrier and the layer shaping member.Type: ApplicationFiled: July 21, 2009Publication date: February 4, 2010Inventors: Shintaro YAMADA, Shin MURAYAMA, Ryuji INOUE, Shuuichi NAKAGAWA, Kazushige OHNISHI