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).

  • Patent number: 5789132
    Abstract: 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: Grant
    Filed: June 10, 1997
    Date of Patent: August 4, 1998
    Assignee: Canon Kabushiki Kaisha
    Inventors: Shinya Mayama, Takeshi Ikeda, Yoshinobu Baba, Naoya Ogata
  • Patent number: 5624778
    Abstract: 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: Grant
    Filed: June 23, 1994
    Date of Patent: April 29, 1997
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yukoh Sato, Shinya Mayama
  • Patent number: 5573880
    Abstract: 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: Grant
    Filed: December 27, 1994
    Date of Patent: November 12, 1996
    Assignee: Canon Kabushiki Kaisha
    Inventors: Shinya Mayama, Takeshi Ikeda, Yuko Sato, Yoshinobu Baba, Hiroshi Aoto, Yasuko Hayashi, Hitoshi Itabashi, Yuzo Tokunaga
  • Patent number: 5565291
    Abstract: 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: Grant
    Filed: March 25, 1994
    Date of Patent: October 15, 1996
    Assignee: Canon Kabushiki Kaisha
    Inventors: Shinya Mayama, Yuko Sato
  • Patent number: 5534581
    Abstract: 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: Grant
    Filed: February 27, 1995
    Date of Patent: July 9, 1996
    Assignee: Canon Kabushiki Kaisha
    Inventors: Noriko Ohtani, Naoto Fujimura, Kiyoshi Sakai, Teigo Sakakibara, Masahiro Inoue, Nobuhiko Takekoshi, Shinya Mayama, Hideo Ohtaki, Tadami Kinugawa, Toshiaki Takada, Yuichi Hashimoto
  • Patent number: 5470687
    Abstract: 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: Grant
    Filed: April 26, 1994
    Date of Patent: November 28, 1995
    Assignee: Canon Kabushiki Kaisha
    Inventors: Shinya Mayama, Takeshi Ikeda, Yoshinobu Baba, Naoya Ogata
  • Patent number: 5418098
    Abstract: 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: Grant
    Filed: June 25, 1992
    Date of Patent: May 23, 1995
    Assignee: Canon Kabushiki Kaisha
    Inventors: Shinya Mayama, Teigo Sakakibara, Noriko Ohtani, Katsumi Aoki, Noriyoshi Ogawa, Satoshi Kanayama
  • Patent number: 5418099
    Abstract: 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: Grant
    Filed: May 18, 1993
    Date of Patent: May 23, 1995
    Assignee: Canon Kabushiki Kaisha
    Inventors: Shinya Mayama, Naoto Fujimura, Toshiyuki Yoshihara, Nobuyuki Hanami, Kiyoshi Sakai, Hideki Anayama, Junichi Kishi, Hideyuki Ainoya, Katsumi Aoki
  • Patent number: 5391446
    Abstract: 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: Grant
    Filed: July 2, 1991
    Date of Patent: February 21, 1995
    Assignee: Canon Kabushiki Kaisha
    Inventors: Noriko Ohtani, Akio Maruyama, Shin Nagahara, Shinya Mayama
  • Patent number: 5391449
    Abstract: 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: Grant
    Filed: March 11, 1993
    Date of Patent: February 21, 1995
    Assignee: Canon Kabushiki Kaisha
    Inventors: Akio Maruyama, Shin Nagahara, Noriko Ohtani, Shinya Mayama
  • Patent number: 5364731
    Abstract: 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: Grant
    Filed: October 25, 1993
    Date of Patent: November 15, 1994
    Assignees: Konica Corporation, Mitsubishi Kasei Corporation
    Inventors: Kunio Shimizu, Nobumasa Sasa, Manabu Watanabe, Hiroshi Ide, Shinya Mayama
  • Patent number: 5320922
    Abstract: 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: Grant
    Filed: September 16, 1992
    Date of Patent: June 14, 1994
    Assignee: Canon Kabushiki Kaisha
    Inventors: Shinya Mayama, Kiyoshi Sakai
  • Patent number: 5283142
    Abstract: 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: Grant
    Filed: February 19, 1992
    Date of Patent: February 1, 1994
    Assignee: Canon Kabushiki Kaisha
    Inventors: Shinya Mayama, Naoto Fujimura, Kiyoshi Sakai, Noriko Ohtani, Katsumi Aoki, Noriyoshi Ogawa, Satoshi Kanayama
  • Patent number: 5254423
    Abstract: 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: Grant
    Filed: October 16, 1992
    Date of Patent: October 19, 1993
    Assignee: Canon Kabushiki Kaisha
    Inventors: Shinya Mayama, Naoto Fujimura, Toshiyuki Yoshihara, Kiyoshi Sakai, Hideki Anayama, Hideyuki Ainoya, Katsumi Aoki
  • Patent number: 5246807
    Abstract: 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: Grant
    Filed: August 3, 1992
    Date of Patent: September 21, 1993
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tetsuro Kanemaru, Hideyuki Takai, Itaru Yamazaki, Shinya Mayama, Masato Tanaka
  • Patent number: 4985337
    Abstract: 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: Grant
    Filed: November 9, 1989
    Date of Patent: January 15, 1991
    Assignees: Konica Corporation, Mitsubishi Kasei Corporation
    Inventors: Nobumasa Sasa, Kunio Shimizu, Manabu Watanabe, Toshiyuki Urano, Shinya Mayama, Tetsuya Masuda