Patents by Inventor Koichi Kuroyama

Koichi Kuroyama 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: 10197932
    Abstract: A toner comprising a coloring agent, an amorphous polyester, a crystalline polyester, ester wax comprising of multiple ester compounds, each having a carbon number selected from 32 to 54 and, hydrophobic silica having an average primary particle diameter of 8 to 35 nm, wherein when the ion intensity ratio of each ester compound having a different carbon number is expressed as percentage, the content (a) of the ester compound having a carbon number of (Cn) showing the maximum intensity ratio is from 20 to 55% by weight of the entire ester wax, and the sum (d) of the content (b) of the ester compound having a carbon number of (Cn?4) and the content (c) of the ester compound having a carbon number of (Cn?2) satisfies the following formula: 0.619?d/a?0.783.
    Type: Grant
    Filed: April 8, 2015
    Date of Patent: February 5, 2019
    Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA TEC KABUSHIKI KAISHA
    Inventors: Tsutomu Katsumata, Koichi Kuroyama
  • Patent number: 10078284
    Abstract: A developer having low-temperature fixability and storage stability, and capable of prolonging the service life is provided. A toner includes a coloring agent, an amorphous polyester, a crystal line polyester, ester wax containing multiple ester compounds, each having a carbon number selected from 32 to 54, and hydrophobic silica having an average primary particle diameter of 8 to 35 nm. When the ion intensity ratio of each ester compound having a different carbon number is expressed as percentage, the content (a) of the ester compound having a carbon number of (Cn) showing the maximum intensity ratio is from 20 to 55% by weight of the entire ester wax, the sum (g) of the content (e) of the ester compound having a carbon number of (Cn+2) and the content (f) of the ester compound having a carbon number of (Cn+4) satisfies the following formula: 0.065?g/a?0.200.
    Type: Grant
    Filed: August 31, 2017
    Date of Patent: September 18, 2018
    Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA TEC KABUSHIKI KAISHA
    Inventors: Koichi Kuroyama, Tsutomu Katsumata
  • Publication number: 20170363983
    Abstract: A developer having low-temperature fixability and storage stability, and capable of prolonging the service life is provided. A toner includes a coloring agent, an amorphous polyester, a crystal line polyester, ester wax containing multiple ester compounds, each having a carbon number selected from 32 to 54, and hydrophobic silica having an average primary particle diameter of 8 to 35 nm. When the ion intensity ratio of each ester compound having a different carbon number is expressed as percentage, the content (a) of the ester compound having a carbon number of (Cn) showing the maximum intensity ratio is from 20 to 55% by weight of the entire ester wax, the sum (g) of the content (e) of the ester compound having a carbon number of (Cn+2) and the content (f) of the ester compound having a carbon number of (Cn+4) satisfies the following formula: 0.065?g/a?0.200.
    Type: Application
    Filed: August 31, 2017
    Publication date: December 21, 2017
    Inventors: Koichi Kuroyama, Tsutomu Katsumata
  • Patent number: 9785073
    Abstract: A developer having low-temperature fixability and storage stability, and capable of prolonging the service life is provided. A toner includes a coloring agent, an amorphous polyester, a crystal line polyester, ester wax containing multiple ester compounds, each having a carbon number selected from 32 to 54, and hydrophobic silica having an average primary particle diameter of 8 to 35 nm. When the ion intensity ratio of each ester compound having a different carbon number is expressed as percentage, the content (a) of the ester compound having a carbon number of (Cn) showing the maximum intensity ratio is from 20 to 55% by weight of the entire ester wax, the sum (g) of the content (e) of the ester compound having a carbon number of (Cn+2) and the content (f) of the ester compound having a carbon number of (Cn+4) satisfies the following formula: 0.065?g/a?0.200.
    Type: Grant
    Filed: April 8, 2015
    Date of Patent: October 10, 2017
    Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA TEC KABUSHIKI KAISHA
    Inventors: Koichi Kuroyama, Tsutomu Katsumata
  • Publication number: 20150309431
    Abstract: A toner comprising a coloring agent, an amorphous polyester, a crystalline polyester, ester wax comprising of multiple ester compounds, each having a carbon number selected from 32 to 54 and, hydrophobic silica having an average primary particle diameter of 8 to 35 nm, wherein when the ion intensity ratio of each ester compound having a different carbon number is expressed as percentage, the content (a) of the ester compound having a carbon number of (Cn) showing the maximum intensity ratio is from 20 to 55% by weight of the entire ester wax, and the sum (d) of the content (b) of the ester compound having a carbon number of (Cn?4) and the content (c) of the ester compound having a carbon number of (Cn?2) satisfies the following formula: 0.619?d/a?0.783.
    Type: Application
    Filed: April 8, 2015
    Publication date: October 29, 2015
    Inventors: Tsutomu Katsumata, Koichi Kuroyama
  • Publication number: 20150309435
    Abstract: A developer having low-temperature fixability and storage stability, and capable of prolonging the service life is provided. A toner includes a coloring agent, an amorphous polyester, a crystal line polyester, ester wax containing multiple ester compounds, each having a carbon number selected from 32 to 54, and hydrophobic silica having an average primary particle diameter of 8 to 35 nm. When the ion intensity ratio of each ester compound having a different carbon number is expressed as percentage, the content (a) of the ester compound having a carbon number of (Cn) showing the maximum intensity ratio is from 20 to 55% by weight of the entire ester wax, the sum (g) of the content (e) of the ester compound having a carbon number of (Cn+2) and the content (f) of the ester compound having a carbon number of (Cn+4) satisfies the following formula: 0.065?g/a?0.200.
    Type: Application
    Filed: April 8, 2015
    Publication date: October 29, 2015
    Inventors: Koichi Kuroyama, Tsutomu Katsumata
  • Publication number: 20150185651
    Abstract: A toner includes a binder resin, a colorant, a wax including 40 to 80 weight percent of an ester wax having an endothermic peak temperature of 65 to 75° C. in a differential scanning calorimetry curve and 60 to 20 weight percent of a carnauba wax having an endothermic peak temperature of 80 to 90° C. in the differential scanning calorimetry curve, and a crystalline polyester material. With respect to the total weight of the binder resin, the wax, and the crystalline polyester material, the wax comprises 4 to 10 weight percent and the crystalline polyester material comprises 3 to 20 weight percent.
    Type: Application
    Filed: December 31, 2013
    Publication date: July 2, 2015
    Applicants: Toshiba Tec Kabushiki Kaisha, Kabushiki Kaisha Toshiba
    Inventor: KOICHI KUROYAMA
  • Patent number: 8486599
    Abstract: According to an embodiment, provided is a developer, which is used for a full-color image forming apparatus, wherein the developer includes a monochrome toner and a color toner, each including a coloring material, an amorphous polyester resin, a crystalline polyester resin, and an ester wax which includes ester compounds having an alkyl group and also having a carbon number of from 32 to 48, the amorphous polyester resin to be blended in the monochrome toner has a melting point (Tm2) of from 140 to 155° C. and the amorphous polyester resin to be blended in the color toner has a melting point (Tm1) of from 115 to 130° C., and the Tm1 and the Tm2 satisfy the following formula (1): 10(° C.)?Tm2?Tm1?40(° C.).
    Type: Grant
    Filed: September 6, 2012
    Date of Patent: July 16, 2013
    Assignee: Toshiba Tec Kabushiki Kaisha
    Inventor: Koichi Kuroyama
  • Publication number: 20130095419
    Abstract: A developer according to an embodiment includes toner particles, wherein the toner particles contain an amorphous polyester resin, a crystalline polyester resin, a coloring material, and a charge control agent containing metal elements of aluminum and magnesium, and have an endothermic peak temperature as measured by a differential scanning calorimeter (DSC) of from 90 to 100° C. and an acid value of from 9 to 19 mgKOH/g.
    Type: Application
    Filed: September 27, 2012
    Publication date: April 18, 2013
    Applicants: TOSHIBA TEC KABUSHIKI KAISHA, KABUSHIKI KAISHA TOSHIBA
    Inventor: Koichi Kuroyama
  • Publication number: 20130071783
    Abstract: According to an embodiment, provided is a developer, which is used for a full-color image forming apparatus, wherein the developer includes a monochrome toner and a color toner, each including a coloring material, an amorphous polyester resin, a crystalline polyester resin, and an ester wax which includes ester compounds having an alkyl group and also having a carbon number of from 32 to 48, the amorphous polyester resin to be blended in the monochrome toner has a melting point (Tm2) of from 140 to 155° C. and the amorphous polyester resin to be blended in the color toner has a melting point (Tm1) of from 115 to 130° C., and the Tm1 and the Tm2 satisfy the following formula (1): 10(° C.)?Tm2?Tm1?40(° C.).
    Type: Application
    Filed: September 6, 2012
    Publication date: March 21, 2013
    Applicants: TOSHIBA TEC KABUSHIKI KAISHA, KABUSHIKI KAISHA TOSHIBA
    Inventor: Koichi Kuroyama
  • Patent number: 8260178
    Abstract: According to one embodiment, a toner cartridge includes a cartridge body, a stirring member configured to stir toner contained in the cartridge body, and a scraping member having elasticity. The stirring member includes a rotation shaft contained in the cartridge body, and plural stirring rods protruded from the rotation shaft and arranged in an axial direction of the rotation shaft. The stirring rods have tips opposite to an inner surface of the cartridge body. The tips of the stirring rods are separate from each other. The scraping member extends in the axial direction of the rotation shaft to scrape toner adhered to the inner surface of the cartridge body, and includes plural elastically deformable strips divided along the axial direction of the rotation shaft.
    Type: Grant
    Filed: June 29, 2010
    Date of Patent: September 4, 2012
    Assignees: Kabushiki Kaisha Toshiba, Toshiba Tec Kabushiki Kaisha
    Inventor: Koichi Kuroyama
  • Publication number: 20110281214
    Abstract: According to one embodiment, there is provided, a developing agent including a toner containing a toner particle containing a coloring agent, an amorphous polyester, a crystalline polyester having an endothermic peak temperature T1 measured by a differential scanning calorimeter, and an ester wax having an endothermic peak temperature T2 measured by a differential scanning calorimeter, and an additive composed of an inorganic oxide particle added onto the surface of the toner particle. The additive has a volume average particle size of from 80 to 200 nm. Also, the developing agent is satisfied with the following expression (1). 15(° C.)?|T2?T1|?50(° C.
    Type: Application
    Filed: May 2, 2011
    Publication date: November 17, 2011
    Applicants: TOSHIBA TEC KABUSHIKI KAISHA, KABUSHIKI KAISHA TOSHIBA
    Inventor: Koichi Kuroyama
  • Publication number: 20110008076
    Abstract: According to one embodiment, a toner cartridge includes a cartridge body, a stirring member configured to stir toner contained in the cartridge body, and a scraping member having elasticity. The stirring member includes a rotation shaft contained in the cartridge body, and plural stirring rods protruded from the rotation shaft and arranged in an axial direction of the rotation shaft. The stirring rods have tips opposite to an inner surface of the cartridge body. The tips of the stirring rods are separate from each other. The scraping member extends in the axial direction of the rotation shaft to scrape toner adhered to the inner surface of the cartridge body, and includes plural elastically deformable strips divided along the axial direction of the rotation shaft.
    Type: Application
    Filed: June 29, 2010
    Publication date: January 13, 2011
    Applicants: KABUSHIKI KAISHA TOSHIBA, TOSHIBA TEC KABUSHIKI KAISHA
    Inventor: Koichi Kuroyama
  • Publication number: 20080241725
    Abstract: In order to solve the foregoing inconveniences, specified addition amounts of a low-resistance external additive and a high-resistance external additive are used in this invention. Furthermore, the toner having been subjected to external addition is subjected to cyclone classification to separate the external additives by force, thereby producing a toner in the same state as in the toner to which a mechanical stress has been applied within the developing unit. When a value of resistance of the toner after externally adding the external additives and a value of resistance of the toner after cyclone classification and a relationship between the both are specified as described later, so far as they fall within the specified ranges, it is possible to provide a developing agent which is free from deterioration of the image quality and is less in toner scattering even by an environmental change or after long-term use.
    Type: Application
    Filed: March 26, 2008
    Publication date: October 2, 2008
    Applicants: KABUSHIKI KAISHA TOSHIBA, TOSHIBA TEC KABUSHIKI KAISHA
    Inventors: Tsutomu Katsumata, Hiroshi Kawaguchi, Koichi Kuroyama
  • Publication number: 20060204877
    Abstract: A developing agent including an additive added to adhere on the surface of a toner particle, wherein the additive comprises a first silica whose primary particle has a first mean volume diameter ranging from 10 to 15 nm, and a second silica whose primary particle has a second mean volume diameter which is larger than the first average particle diameter, a coverage of the first silica to the toner particle is confined within the range of 30 to 50%, and a ratio of projecting area of the second silica to projecting area of the first silica is confined within the range of 70 to 120%.
    Type: Application
    Filed: October 11, 2005
    Publication date: September 14, 2006
    Inventor: Koichi Kuroyama
  • Patent number: 6895192
    Abstract: After a toner empty state, toner is filled. Following the filling of toner, a forcible toner replenishment mode is performed. After release of the forcible toner replenishment mode, a printer CPU replenishes only fresh toner and does not replenish recycled toner while image formation is performed on a predetermined number of paper sheets or while a developing device is driven for a predetermined time.
    Type: Grant
    Filed: April 29, 2003
    Date of Patent: May 17, 2005
    Assignees: Kabushiki Kaisha Toshiba, Toshiba Tec Kabushiki Kaisha
    Inventors: Tetsuo Katoh, Koichi Kuroyama
  • Publication number: 20030202806
    Abstract: After a toner empty state, toner is filled. Following the filling of toner, a forcible toner replenishment mode is performed. After release of the forcible toner replenishment mode, a printer CPU replenishes only fresh toner and does not replenishment recycled toner while image formation is performed on a predetermined number of paper sheets or while a developing device is driven for a predetermined time.
    Type: Application
    Filed: April 29, 2003
    Publication date: October 30, 2003
    Applicants: KABUSHIKI KAISHA TOSHIBA, TOSHIBA TEC KABUSHIKI KAISHA
    Inventors: Tetsuo Katoh, Koichi Kuroyama