Patents by Inventor Shinya Mayama
Shinya Mayama 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: 5789132Abstract: A toner for developing electrostatic images is comprised of toner particles having a number average particle diameter of from 0.5 .mu.m to 5.0 .mu.m, in which toner particles with a particle diameter of 6.0 .mu.m or larger is included in a proportion of not more than 5% by number. The toner particles are obtained by a process having the steps of dispersing a monomer composition containing at least a colorant, a charge control agent, or a mixture of these, and a polymerizable monomer, in free space formed in a polymeric medium, and polymerizing the monomer composition dispersed in said free space.Type: GrantFiled: June 10, 1997Date of Patent: August 4, 1998Assignee: Canon Kabushiki KaishaInventors: Shinya Mayama, Takeshi Ikeda, Yoshinobu Baba, Naoya Ogata
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Patent number: 5624778Abstract: The present invention discloses a carrier for use in electrophotography and a two-component type developer for developing an electrostatic image comprising a toner and the carrier. The carrier has magnetic material and a resin. The resin has a polycarbonate resin having a crystallinity of 0.25 or less.Type: GrantFiled: June 23, 1994Date of Patent: April 29, 1997Assignee: Canon Kabushiki KaishaInventors: Yukoh Sato, Shinya Mayama
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Patent number: 5573880Abstract: A carrier for use in electrophotography has carrier particles. The carrier particles each comprise a carrier core particle and a resin for coating the carrier core particle and having a resistivity of 10.sup.10 .OMEGA..multidot.cm or above under conditions of a temperature of 23.degree. C. and a humidity of 50% RH. The carrier particles have an average particle diameter of not larger than 100 .mu.m and a resistivity of 10.sup.10 .OMEGA..multidot.cm or above. The carrier particles comprise not less than 80% by number of resin-coated carrier particles whose carrier core particles are each coated with a resin in a coverage of not less than 90%.Type: GrantFiled: December 27, 1994Date of Patent: November 12, 1996Assignee: Canon Kabushiki KaishaInventors: Shinya Mayama, Takeshi Ikeda, Yuko Sato, Yoshinobu Baba, Hiroshi Aoto, Yasuko Hayashi, Hitoshi Itabashi, Yuzo Tokunaga
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Patent number: 5565291Abstract: A two-component type developer for developing an electrostatic image is constituted by a toner and a carrier. The carrier is composed of a magnetic material and a resin either coating or dispersing the magnetic material. The resin comprises a copolymer having structural units of the following formulae [1] and [2]: ##STR1## wherein A denotes a C.sub.1 -C.sub.10 linear, branched or cyclic alkylidene group, aryl-substituted alkylidene group or arylenedialkylidene group, --O--, --S--, --CO--, --SO-- or --SO.sub.2 --; and R.sub.1 -R.sub.4 independently denote hydrogen, halogen, or a C.sub.1 -C.sub.4 alkyl or alkenyl group: ##STR2## wherein R.sub.5 denotes a C.sub.2 -C.sub.6 alkylene or alkylidene group; R.sub.6 and R.sub.7 denote a C.sub.1 -C.sub.3 alkyl group, a phenyl group or a substituted phenyl group; and n is an integer of 1-200.Type: GrantFiled: March 25, 1994Date of Patent: October 15, 1996Assignee: Canon Kabushiki KaishaInventors: Shinya Mayama, Yuko Sato
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Patent number: 5534581Abstract: A transfer material carrying member has a copolymer and conductive particles; the copolymer has a component unit represented by the Formula (I) and a component unit represented by the Formula (II), and the component unit represented by Formula (II) is in an amount of from 0.1% by weight to 50% by weight based on the total weight of the copolymer.Type: GrantFiled: February 27, 1995Date of Patent: July 9, 1996Assignee: Canon Kabushiki KaishaInventors: Noriko Ohtani, Naoto Fujimura, Kiyoshi Sakai, Teigo Sakakibara, Masahiro Inoue, Nobuhiko Takekoshi, Shinya Mayama, Hideo Ohtaki, Tadami Kinugawa, Toshiaki Takada, Yuichi Hashimoto
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Patent number: 5470687Abstract: A toner for developing electrostatic images is comprised of toner particles having a number average particle diameter of from 0.5 .mu.m to 5.0 .mu.m, in which toner particles with a particle diameter of 6.0 .mu.m or larger is included in a proportion of not more than 5% by number. The toner particles are obtained by a process having the steps of dispersing a monomer composition containing at least a colorant, a charge control agent, or a mixture of these, and a polymerizable monomer, in free space formed in a polymeric medium, and polymerizing the monomer composition dispersed in said free space.Type: GrantFiled: April 26, 1994Date of Patent: November 28, 1995Assignee: Canon Kabushiki KaishaInventors: Shinya Mayama, Takeshi Ikeda, Yoshinobu Baba, Naoya Ogata
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Patent number: 5418098Abstract: There is disclosed an electrophotographic photosensitive member comprising a conductive support and a photosensitive layer provided thereon, wherein the photosensitive layer contains a random copolymer having a structural unit represented by the following Formula (I): ##STR1## and a structural unit represented by the following Formula (II): ##STR2##Type: GrantFiled: June 25, 1992Date of Patent: May 23, 1995Assignee: Canon Kabushiki KaishaInventors: Shinya Mayama, Teigo Sakakibara, Noriko Ohtani, Katsumi Aoki, Noriyoshi Ogawa, Satoshi Kanayama
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Patent number: 5418099Abstract: The present invention relates to an electrophotographic photosensitive member comprising an electroconductive support and a photosensitive layer formed thereon: the surface layer of the electrophotographic photosensitive member containing a first copolymer of a first construction unit represented by Formula (1) and a second construction unit represented by Formula (2), and a second copolymer of a third construction unit represented by Formula (3) and a fourth construction unit represented by Formula (4): ##STR1##Type: GrantFiled: May 18, 1993Date of Patent: May 23, 1995Assignee: Canon Kabushiki KaishaInventors: Shinya Mayama, Naoto Fujimura, Toshiyuki Yoshihara, Nobuyuki Hanami, Kiyoshi Sakai, Hideki Anayama, Junichi Kishi, Hideyuki Ainoya, Katsumi Aoki
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Patent number: 5391446Abstract: An image holding member rich in durability and suitably used as an electrophotographic photosensitive member or an electrostatic image-holding dielectric member is prepared by coating a support with a resinous layer formed by polymerization of a phosphazene polyene represented by the following formida: ##STR1## wherein R.sub.1 denotes an ethylenically unsaturated group, preferably an acrylic group represented by --R.sub.2 --OCO--C(R.sub.3)=CH.sub.2, wherein R.sub.2 denotes an alkylene group, arylene group, alkyl-substituted arylene group, alkylamide group or arylamide group, and R.sub.3 denotes a hydrogen atom or a methyl group. The resinous layer may constitute a photosensitive layer, a dielectric layer, or a protective layer covering these layers.Type: GrantFiled: July 2, 1991Date of Patent: February 21, 1995Assignee: Canon Kabushiki KaishaInventors: Noriko Ohtani, Akio Maruyama, Shin Nagahara, Shinya Mayama
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Patent number: 5391449Abstract: An electrophotographic photosensitive member is formed by disposing a photosensitive layer and a protective layer in this order on an electroconductive support. The protective layer is formed from a resin obtained by polymerization of a curable acrylic monomer having at least three acrylic groups, i.e., acryloyl and/or methacryloyl groups. The protective layer not only shows a good durability against wearing but also can contain fine electroconductive particles therein with a good dispersibility because of the presence of the acrylic groups aiding the dispersion.Type: GrantFiled: March 11, 1993Date of Patent: February 21, 1995Assignee: Canon Kabushiki KaishaInventors: Akio Maruyama, Shin Nagahara, Noriko Ohtani, Shinya Mayama
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Patent number: 5364731Abstract: Disclosed is a multi-color transfer image forming method, which comprises subjecting a colored image forming material having a coloration recording layer comprising at least two layers and containing a photosensitive material and a colorant on a support to aqueous development after imagewise exposure, thereby forming a colored image, transferring the colored image to an image receiving member through the outermost surface of the coloration recording layer and then transferring at least one colored image with different hue onto the same image receiving member in conformity with the colored image, characterized in that the layer of the coloration recording layer remotest from the support is a layer adherable to the image receiving member, and only the colored image portion is transferred onto the image receiving member to have the image receiving member surface exposed at the non-image portion of the multi-color image.Type: GrantFiled: October 25, 1993Date of Patent: November 15, 1994Assignees: Konica Corporation, Mitsubishi Kasei CorporationInventors: Kunio Shimizu, Nobumasa Sasa, Manabu Watanabe, Hiroshi Ide, Shinya Mayama
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Patent number: 5320922Abstract: An electrophotographic photosensitive medium has a photosensitive layer on an electroconductive base, the medium having at least one intermediate layer between the base and the photosensitive layer, the intermediate layer containing indium oxide - tin oxide solid solution (ITO) powder and a binder resin. An electrophotographic apparatus includes a photosensitive medium; a device for forming latent images; a device for developing formed latent images; and a device for transferring developed images to a transfer member.Type: GrantFiled: September 16, 1992Date of Patent: June 14, 1994Assignee: Canon Kabushiki KaishaInventors: Shinya Mayama, Kiyoshi Sakai
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Patent number: 5283142Abstract: The present invention provides an image-holding member which comprises an electroconductive support and a resin layer formed on the support, wherein the surface layer of the image-holding member contains a copolymer having the structure units represented by the formulas [I] and [II]: ##STR1## where A is a linear, branched or cyclic alkylidene group of 1 to 10 carbon atoms, an aryl-substituted alkylidene group, arylene-dialkylidene group, --O--, --S--, --CO--, --SO--, or --SO.sub.2 --; and R.sub.1, R.sub.2, R.sub.3, and R.sub.4 are respectively hydrogen, halogen, or an alkyl or alkenyl group of 1 to 4 carbons; ##STR2## where R.sub.5 is an alkylene or alkylidene group of 2 to 6 carbons; R.sub.6 and R.sub.7 are respectively an alkyl group of 1 to 3 carbons, a phenyl or substituted phenyl group; and n is an integer of from 1 to 200, and the copolymer containing the structure unit of the formula [II] in an amount of from 0.1 to 50% by weight Of the total weight of the copolymer.Type: GrantFiled: February 19, 1992Date of Patent: February 1, 1994Assignee: Canon Kabushiki KaishaInventors: Shinya Mayama, Naoto Fujimura, Kiyoshi Sakai, Noriko Ohtani, Katsumi Aoki, Noriyoshi Ogawa, Satoshi Kanayama
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Patent number: 5254423Abstract: The present invention provides an electrophotographic photosensitive member comprising a conductive support and a photosensitive layer provided thereon, wherein the surface layer of the electrophotographic photosensitive member contains a polymer having a component unit represented by the following Formula (1) and a polymer having a component unit represented by the following Formula (2) and a component unit represented by the following Formula (3) in a certain proportion.Type: GrantFiled: October 16, 1992Date of Patent: October 19, 1993Assignee: Canon Kabushiki KaishaInventors: Shinya Mayama, Naoto Fujimura, Toshiyuki Yoshihara, Kiyoshi Sakai, Hideki Anayama, Hideyuki Ainoya, Katsumi Aoki
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Patent number: 5246807Abstract: The present invention relates to an electrophotographic photosensitive member. The photosensitive member has an electroconductive support and a photosensitive layer formed thereon containing oxytitanium phthalocyanine, and a surface layer of the photosensitive member contains a copolymer having a first and second structural units represented by the formulas ##STR1## Further the invention relates to an electrophotographic apparatus, device unit, and facsimile machine utilizing the electrophotographic photosensitive member.Type: GrantFiled: August 3, 1992Date of Patent: September 21, 1993Assignee: Canon Kabushiki KaishaInventors: Tetsuro Kanemaru, Hideyuki Takai, Itaru Yamazaki, Shinya Mayama, Masato Tanaka
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Patent number: 4985337Abstract: There is disclosed an image forming method which comprises forming an image portion by exposing and developing an image forming material having a light-sensitive composition, and transferring only the image portion onto an image receiving material with the non-image portion of the image receiving material being exposed, wherein the light-sensitive composition contains:(1) at least one selected from:(a) o-quinonediazide compounds; and(b) compositions containing both of a photoacid generating agent and a compound having at least one bond decomposable with the acid; and(2) a polymeric compound having a structure unit represented by the following formula in the molecular structure:CH.sub.2 --CH(OCOR)--wherein R represents an alkyl group having 1 to 17 carbon atoms.Type: GrantFiled: November 9, 1989Date of Patent: January 15, 1991Assignees: Konica Corporation, Mitsubishi Kasei CorporationInventors: Nobumasa Sasa, Kunio Shimizu, Manabu Watanabe, Toshiyuki Urano, Shinya Mayama, Tetsuya Masuda