Patents by Inventor Maki Okajima

Maki Okajima 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).

  • Publication number: 20210132519
    Abstract: A toner includes a toner particle containing a binder resin and an inorganic infrared absorbent particle, wherein (1) in spectrometry of a fixed image obtained by fixing an unfixed image formed on a recording material by using the toner in a loading amount of 0.30 mg/cm2, a maximum value of a light absorbance in a wavelength range of 400 nm or more and 800 nm or less is 10% or less, and (2) in cross section observation of the toner particle using a transmission electron microscope, when a circle having the center of gravity of a cross section image of the toner particle as the center thereof and having a radius of 2.0 ?m is drawn and the circle is divided into four to form four quadrants, a coefficient of variation in number of the inorganic infrared absorbent particles observed in each quadrant is 0.50 or less.
    Type: Application
    Filed: December 31, 2020
    Publication date: May 6, 2021
    Inventors: Akira Hashimoto, Takeshi Yamamoto, Ryuji Higashi, Takayuki Toyoda, Maki Okajima, Akiko Kitao, Koichi Suzuki
  • Patent number: 10151990
    Abstract: A toner comprising a toner particle that contains a binder resin, wherein the surface of the toner particle is covered with a resin A; the modulus of elasticity Ea of the resin A and the modulus of elasticity Eb of the binder resin satisfy the following formula: 0.5?(Ea/Eb)×100?50.0; and the adhesion force AT of the toner particle is at least 500 nN when a probe having spherical SiO2 attached at the tip of a cantilever is pressed into the toner particle at 3 ?N.
    Type: Grant
    Filed: November 16, 2017
    Date of Patent: December 11, 2018
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Masao Suzuki, Kazuyuki Sato, Shohei Fukuya, Atsushi Nakamoto, Makoto Fukatsu, Takahiro Kawamoto, Maki Okajima, Masayoshi Kato, Yasunori Chigono, Takeshi Yamamoto
  • Publication number: 20180149989
    Abstract: A toner comprising a toner particle that contains a binder resin, wherein the surface of the toner particle is covered with a resin A; the modulus of elasticity Ea of the resin A and the modulus of elasticity Eb of the binder resin satisfy the following formula: 0.5?(Ea/Eb)×100?50.0; and the adhesion force AT of the toner particle is at least 500 nN when a probe having spherical SiO2 attached at the tip of a cantilever is pressed into the toner particle at 3 ?N.
    Type: Application
    Filed: November 16, 2017
    Publication date: May 31, 2018
    Inventors: Masao Suzuki, Kazuyuki Sato, Shohei Fukuya, Atsushi Nakamoto, Makoto Fukatsu, Takahiro Kawamoto, Maki Okajima, Masayoshi Kato, Yasunori Chigono, Takeshi Yamamoto
  • Patent number: 9705087
    Abstract: Provided is an organic light emitting device with enhanced durability during continuous driving. The organic light emitting device includes: an anode, a cathode, and an organic compound layer being placed between the anode and the cathode and including at least a hole transport layer and an emission layer, in which: the emission layer contains a blue light emitting material; the hole transport layer contains a plurality of kinds of organic compounds; and an organic compound having the smallest ionization potential among the organic compounds includes a compound having no absorption spectrum peak in a blue color wavelength region in a radical cation state.
    Type: Grant
    Filed: February 25, 2016
    Date of Patent: July 11, 2017
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Minako Nakasu, Masataka Yashima, Hajime Muta, Keiji Okinaka, Tomona Yamaguchi, Tomonari Horikiri, Maki Okajima, Naoki Yamada
  • Publication number: 20160181528
    Abstract: Provided is an organic light emitting device with enhanced durability during continuous driving. The organic light emitting device includes: an anode, a cathode, and an organic compound layer being placed between the anode and the cathode and including at least a hole transport layer and an emission layer, in which: the emission layer contains a blue light emitting material; the hole transport layer contains a plurality of kinds of organic compounds; and an organic compound having the smallest ionization potential among the organic compounds includes a compound having no absorption spectrum peak in a blue color wavelength region in a radical cation state.
    Type: Application
    Filed: February 25, 2016
    Publication date: June 23, 2016
    Inventors: MINAKO NAKASU, MASATAKA YASHIMA, HAJIME MUTA, KEIJI OKINAKA, TOMONA YAMAGUCHI, TOMONARI HORIKIRI, MAKI OKAJIMA, NAOKI YAMADA
  • Patent number: 9331296
    Abstract: Aspects of the present invention provide a blue organic light-emitting device having a continuous operation lifetime. An organic light-emitting device includes a light-emitting layer containing a dopant having the ability to trap electrons or holes, and a hole-blocking layer or electron-blocking layer, in which the difference between the LUMO of the dopant and the LUMO of a host material, the size relationship between the HOMO of the host material and the HOMO of the dopant, and the difference between the T1 of the host material and the T1 of the hole-blocking layer or between the T1 of the host material and the T1 of the electron-blocking layer, are specified.
    Type: Grant
    Filed: March 14, 2011
    Date of Patent: May 3, 2016
    Assignee: Canon Kabushiki Kaisha
    Inventors: Maki Okajima, Keiji Okinaka, Tetsuo Takahashi, Hajime Muta, Yohei Iwasaki, Minako Nakasu, Naoki Yamada, Yosuke Nishide
  • Patent number: 9312494
    Abstract: Provided is an organic light emitting device with enhanced durability during continuous driving. The organic light emitting device includes: an anode, a cathode, and an organic compound layer being placed between the anode and the cathode and including at least a hole transport layer and an emission layer, in which: the emission layer contains a blue light emitting material; the hole transport layer contains a plurality of kinds of organic compounds; and an organic compound having the smallest ionization potential among the organic compounds includes a compound having no absorption spectrum peak in a blue color wavelength region in a radical cation state.
    Type: Grant
    Filed: December 2, 2010
    Date of Patent: April 12, 2016
    Assignee: Canon Kabushiki Kaisha
    Inventors: Minako Nakasu, Masataka Yashima, Hajime Muta, Keiji Okinaka, Tomona Yamaguchi, Tomonari Horikiri, Maki Okajima, Naoki Yamada
  • Patent number: 9115055
    Abstract: A novel fluorenylamine compound represented by a general formula below, where R1 to R6 are each independently selected from a hydrogen atom and alkyl groups; R21 to R23 are each independently selected from a hydrogen atom and the alkyl groups; and the alkyl groups are a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group.
    Type: Grant
    Filed: October 18, 2010
    Date of Patent: August 25, 2015
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tomonari Horikiri, Naoki Yamada, Maki Okajima, Minako Nakasu
  • Patent number: 8624231
    Abstract: A benzopyrene compound represented by a general formula [1] below, where one of X1 and X2 represents a substituted or unsubstituted aryl group; another one of X1 and X2 represents a hydrogen atom; R represents an alkyl group; and n represents 0 or 1.
    Type: Grant
    Filed: March 30, 2011
    Date of Patent: January 7, 2014
    Assignee: Canon Kabushiki Kaisha
    Inventors: Naoki Yamada, Yosuke Nishide, Maki Okajima, Tetsuo Takahashi, Jun Kamatani, Akihito Saitoh
  • Patent number: 8354788
    Abstract: An organic light emitting device having long continuous driving lifetime is provided. The organic light emitting device includes an anode, a cathode, and an emission layer formed of an organic compound arranged between the anode and the cathode, in which the emission layer includes a light emitting material and a material having a smallest ionization potential, and an absorption spectrum in a radical cation state of the material having the smallest ionization potential in the emission layer does not have its absorption peak in an emission wavelength region of the light emitting material.
    Type: Grant
    Filed: May 14, 2009
    Date of Patent: January 15, 2013
    Assignee: Canon Kabushiki Kaisha
    Inventors: Keiji Okinaka, Masataka Yashima, Maki Okajima, Hajime Muta
  • Publication number: 20130001542
    Abstract: Aspects of the present invention provide a blue organic light-emitting device having a continuous operation lifetime. An organic light-emitting device includes a light-emitting layer containing a dopant having the ability to trap electrons or holes, and a hole-blocking layer or electron-blocking layer, in which the difference between the LUMO of the dopant and the LUMO of a host material, the size relationship between the HOMO of the host material and the HOMO of the dopant, and the difference between the T1 of the host material and the T1 of the hole-blocking layer or between the T1 of the host material and the T1 of the electron-blocking layer, are specified.
    Type: Application
    Filed: March 14, 2011
    Publication date: January 3, 2013
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Maki Okajima, Keiji Okinaka, Tetsuo Takahashi, Hajime Muta, Yohei Iwasaki, Minako Nakasu, Naoki Yamada, Yosuke Nishide
  • Patent number: 8299459
    Abstract: The present invention provides an organic light emitting device which shows a blue light emission hue of remarkably good color purity and has a high-efficiency and high-luminance optical output.
    Type: Grant
    Filed: September 28, 2010
    Date of Patent: October 30, 2012
    Assignee: Canon Kabushiki Kaisha
    Inventors: Maki Okajima, Naoki Yamada
  • Publication number: 20120211742
    Abstract: A novel fluorenylamine compound represented by a general formula below, where R1 to R6 are each independently selected from a hydrogen atom and alkyl groups; R21 to R23 are each independently selected from a hydrogen atom and the alkyl groups; and the alkyl groups are a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group.
    Type: Application
    Filed: October 18, 2010
    Publication date: August 23, 2012
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Tomonari Horikiri, Naoki Yamada, Maki Okajima, Minako Nakasu
  • Publication number: 20120205639
    Abstract: Provided is an organic light emitting device with enhanced durability during continuous driving. The organic light emitting device includes: an anode, a cathode, and an organic compound layer being placed between the anode and the cathode and including at least a hole transport layer and an emission layer, in which: the emission layer contains a blue light emitting material; the hole transport layer contains a plurality of kinds of organic compounds; and an organic compound having the smallest ionization potential among the organic compounds includes a compound having no absorption spectrum peak in a blue color wavelength region in a radical cation state.
    Type: Application
    Filed: December 2, 2010
    Publication date: August 16, 2012
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Minako Nakasu, Masataka Yashima, Hajime Muta, Keiji Okinaka, Tomona Yamaguchi, Tomonari Horikiri, Maki Okajima, Naoki Yamada
  • Publication number: 20120132901
    Abstract: An organic light-emitting device includes an anode, a cathode, and an organic compound layer interposed between the anode and the cathode. The organic compound layer contains a pyrene derivative.
    Type: Application
    Filed: July 23, 2010
    Publication date: May 31, 2012
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Naoki Yamada, Jun Kamatani, Maki Okajima, Ryota Ooishi, Akihito Saitoh
  • Publication number: 20110240976
    Abstract: A benzopyrene compound represented by a general formula [1] below, where one of X1 and X2 represents a substituted or unsubstituted aryl group; another one of X1 and X2 represents a hydrogen atom; R represents an alkyl group; and n represents 0 or 1.
    Type: Application
    Filed: March 30, 2011
    Publication date: October 6, 2011
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Naoki Yamada, Yosuke Nishide, Maki Okajima, Tetsuo Takahashi, Jun Kamatani, Akihito Saitoh
  • Publication number: 20110204349
    Abstract: The present invention provides an organic light emitting device which shows a blue light emission hue of remarkably good color purity and has a high-efficiency and high-luminance optical output.
    Type: Application
    Filed: September 28, 2010
    Publication date: August 25, 2011
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Maki Okajima, Naoki Yamada
  • Patent number: 7982213
    Abstract: A novel phenanthroline compound is provided which is represented by the general formula [I]: (wherein R1, R2, R3, R4, R5 and R6 are the same or different and each is selected from a hydrogen atom, an unsubstituted or substituted alkyl group, an unsubstituted or substituted aralkyl group, an unsubstituted or substituted aryl group, an unsubstituted or substituted heterocyclic group, and a halogen atom; and Ar1 and Ar2 are the same or different and each is selected from an unsubstituted or substituted fluorenyl group, an unsubstituted or substituted fluoranthenyl group, an unsubstituted or substituted perylenyl group, and an unsubstituted or substituted carbazolyl group). An organic light emitting device using the phenanthroline compound is also provided that has a light output with a high efficiency and a high luminance and has a high long-term durability.
    Type: Grant
    Filed: May 6, 2009
    Date of Patent: July 19, 2011
    Assignee: Canon Kabushiki Kaisha
    Inventors: Maki Okajima, Tatsundo Kawai, Takao Takiguchi, Koichi Suzuki, Akihiro Senoo, Toshinori Hasegawa, Keiji Okinaka
  • Publication number: 20110001864
    Abstract: An organic light emitting device having long continuous driving lifetime is provided. The organic light emitting device includes an anode, a cathode, and an emission layer formed of an organic compound arranged between the anode and the cathode, in which the emission layer includes a light emitting material and a material having a smallest ionization potential, and an absorption spectrum in a radical cation state of the material having the smallest ionization potential in the emission layer does not have its absorption peak in an emission wavelength region of the light emitting material.
    Type: Application
    Filed: May 14, 2009
    Publication date: January 6, 2011
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Keiji Okinaka, Masataka Yashima, Maki Okajima, Hajime Muta
  • Publication number: 20100327274
    Abstract: An organic blue-light-emitting device having a high emission efficiency and a long continuous driving lifetime is provided. An organic light-emitting device 20 includes an anode 2, a cathode 5, and a stacked body which is interposed between the anode 2 and the cathode 5 and includes at least a layer which forms a light-emitting region (emission layer 6).
    Type: Application
    Filed: March 31, 2009
    Publication date: December 30, 2010
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Maki Okajima, Akihito Saitoh, Masumi Itabashi, Masanori Muratsubaki, Naoki Yamada, Hiroki Ohrui, Chika Negishi, Tetsuya Kosuge, Takayuki Horiuchi, Takeshi Sekiguchi, Hiroyuki Tomono