Patents by Inventor Kazuhiro Egawa

Kazuhiro Egawa 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: 10061250
    Abstract: An image forming apparatus includes a photoconductor, a charger, an exposure device, a transfer device, a first and a second surface voltmeter, and a processor. At the first rotation of the photoconductor, the charger charges a charge area on the photoconductor, the exposure device exposes a part of an exposure area in an axial direction of the photoconductor, and the transfer device charges an exposed and unexposed area. At the second rotation, the charger charges the charge area, and the exposure device exposes the exposed and unexposed area at the first rotation. After the exposure at the second rotation, the first surface voltmeter measures a surface potential V1 of the unexposed area at the first rotation, and the second surface voltmeter measures a surface potential V2 of the exposed area at the first rotation. The processor evaluates a life of the photoconductor based on the surface potentials V1 and V2.
    Type: Grant
    Filed: November 7, 2017
    Date of Patent: August 28, 2018
    Assignee: Ricoh Company, Ltd.
    Inventors: Daisuke Nii, Noriyasu Saito, Kazuhiro Egawa
  • Publication number: 20180150013
    Abstract: An image forming apparatus includes a photoconductor, a charger, an exposure device, a transfer device, a first and a second surface voltmeter, and a processor. At the first rotation of the photoconductor, the charger charges a charge area on the photoconductor, the exposure device exposes a part of an exposure area in an axial direction of the photoconductor, and the transfer device charges an exposed and unexposed area. At the second rotation, the charger charges the charge area, and the exposure device exposes the exposed and unexposed area at the first rotation. After the exposure at the second rotation, the first surface voltmeter measures a surface potential V1 of the unexposed area at the first rotation, and the second surface voltmeter measures a surface potential V2 of the exposed area at the first rotation. The processor evaluates a life of the photoconductor based on the surface potentials V1 and V2.
    Type: Application
    Filed: November 7, 2017
    Publication date: May 31, 2018
    Inventors: Daisuke NII, Noriyasu SAITO, Kazuhiro EGAWA
  • Patent number: 9740116
    Abstract: A photoconductor includes an electroconductive substrate; an intermediate layer overlying the electroconductive substrate; and a photosensitive layer overlying the intermediate layer. The intermediate layer includes a metal oxide particle and a binder resin, and satisfies the following relations (1) and (2): Smr=Scut/Sk??(1) 0.4?Smr?0.6??(2) where Smr represents an areal ratio of concave parts; Sk represents a reference area; and a Scut represents a cross-sectional area obtained by cutting a three-dimensional curved surface obtained from the reference area with an average height surface, the average height surface being a surface constituted of averaged height of all measured height data.
    Type: Grant
    Filed: February 26, 2016
    Date of Patent: August 22, 2017
    Assignee: Ricoh Company, Ltd.
    Inventors: Nobutaka Eguchi, Akihiro Sugino, Hidetoshi Kami, Keisuke Shimoyama, Kazuhiro Egawa
  • Patent number: 9523930
    Abstract: A photoconductor, including an electroconductive substrate; an intermediate layer overlying the electroconductive substrate; and a photosensitive layer overlying the intermediate layer. The intermediate layer includes a metal oxide and a binder resin, and has a WRa (LLH) less than 0.12 ?m and WRa (LHH) of from 0.03 to 0.2 ?m in a curve.
    Type: Grant
    Filed: February 3, 2015
    Date of Patent: December 20, 2016
    Assignee: Ricoh Company, Ltd.
    Inventors: Hidetoshi Kami, Nobutaka Eguchi, Akihiro Sugino, Keisuke Shimoyama, Kazuhiro Egawa
  • Publication number: 20160274475
    Abstract: A photoconductor includes an electroconductive substrate; an intermediate layer overlying the electroconductive substrate; and a photosensitive layer overlying the intermediate layer. The intermediate layer includes a metal oxide particle and a binder resin, and satisfies the following relations (1) and (2): Smr=Scut/Sk??(1) 0.4?Smr?0.6??(2) wherein Smr represents an areal ratio of projecting parts; Sk represents a reference area; and a Scut represents a cross-sectional area obtained by cutting a three-dimensional curved surface obtained from the reference area with an average height surface, the average height surface being a surface constituted of averaged height of all measured height data.
    Type: Application
    Filed: February 26, 2016
    Publication date: September 22, 2016
    Inventors: Nobutaka EGUCHI, Akihiro Sugino, Hidetoshi Kami, Keisuke Shimoyama, Kazuhiro Egawa
  • Patent number: 9298113
    Abstract: An electrophotographic photoconductor, including: an electroconductive substrate; and at least a photoconductive layer and a surface layer in this order over the electroconductive substrate, wherein the surface layer includes a resin having no charge transport properties, and first inorganic fine particles, and wherein the first inorganic fine particles are inorganic fine particles having surfaces modified with at least one of a primary amino group and a secondary amino group, and a volume resistivity of the first inorganic fine particles is 1×108 ?·cm or less.
    Type: Grant
    Filed: January 15, 2014
    Date of Patent: March 29, 2016
    Assignee: Ricoh Company, Ltd.
    Inventors: Toshihiro Ishida, Hiroshi Ikuno, Tetsuya Toshine, Naohiro Toda, Takafumi Iwamoto, Kazuhiro Egawa
  • Patent number: 9122183
    Abstract: An electrophotographic photoreceptor, including an electroconductive substrate; a photosensitive layer overlying the electroconductive substrate; and a surface layer overlying the photosensitive layer, wherein the surface layer includes a resin having no charge transportability; and an inorganic particulate material, wherein the inorganic particulate material is a zinc oxide doped with a boron group, and wherein the electrophotographic photoreceptor has a surface specific resistivity (R1) not less than 1013 ?/cm2 when the surface layer has an electric field intensity of 1×104 V/cm, and a ratio (R1/R15) of the surface specific resistivity (R1) to a surface specific resistivity (R15) when the surface layer has an electric field intensity of 1.5×105 V/cm of from 100 to 5,000.
    Type: Grant
    Filed: March 5, 2013
    Date of Patent: September 1, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Tetsuya Toshine, Hiroshi Ikuno, Naohiro Toda, Takafumi Iwamoto, Kazuhiro Egawa, Toshihiro Ishida
  • Publication number: 20150227063
    Abstract: A photoconductor, including an electroconductive substrate; an intermediate layer overlying the electroconductive substrate; and a photosensitive layer overlying the intermediate layer. The intermediate layer includes a metal oxide and a binder resin, and has a WRa (LLH) less than 0.12 ?m and WRa (LHH) of from 0.03 to 0.2 ?m in a curve.
    Type: Application
    Filed: February 3, 2015
    Publication date: August 13, 2015
    Inventors: Hidetoshi KAMI, Nobutaka EGUCHI, Akihiro SUGINO, Keisuke SHIMOYAMA, Kazuhiro EGAWA
  • Patent number: 9037067
    Abstract: An image forming apparatus including at least a photoreceptor; and a cleaning blade formed of a strip-shaped elastic blade to contact an edge line to the surface of the photoreceptor, wherein the photoreceptor includes a surface layer comprising a particulate material, and the edge line of the cleaning blade includes a substrate of the elastic blade; a mixed layer having a thickness not less than 1.0 ?m, formed of the substrate and at least one of an acrylic resin and a methacrylic resin, located at the surface of the substrate; and a surface layer having a thickness not less than 0.1 ?m, formed of at least one of an acrylic resin and a methacrylic resin, located on the surface of the substrate.
    Type: Grant
    Filed: January 29, 2013
    Date of Patent: May 19, 2015
    Assignee: RICOH COMPANY, LTD.
    Inventors: Hiroshi Ikuno, Yohta Sakon, Masahiro Ohmori, Kazuhiro Egawa, Tetsuya Toshine
  • Publication number: 20140234763
    Abstract: An image forming apparatus includes an image bearing member having a photosensitive layer and a sub-surface layer having a charge transportability, overlying the photosensitive layer wherein the sub-surface layer is formed of a cured material formed of a radical polymerizable monomer having three or more functional groups with no charge transport structure and a radical polymerizable compound having a charge transport structure, wherein the arithmetical mean roughness WRa of about each of frequency components of HMH, HML, and HLH obtained by wavelet conversion of values measured by a surface texture and the contour form measuring device ranges from 0.0002 ?m to 0.005 ?m and WRa (LLH) is 0.05 ?m or less, wherein the sub-surface layer contains at least one of a particular oxazole compound or a particular diamine compound.
    Type: Application
    Filed: February 6, 2014
    Publication date: August 21, 2014
    Inventors: Akihiro SUGINO, Keisuke Shimoyama, Tomoharu Asano, Hidetoshi Kami, Nobutaka Eguchi, Kazuhiro Egawa, Tomoyuki Shimada, Ryota Arai, Masayoshi Nomura
  • Patent number: 8795935
    Abstract: An electrophotographic photoconductor having a photosensitive layer and a crosslinked resin surface layer over a support, wherein shapes of concaves and convexes in a surface of the electrophotographic photoconductor are measured by a surface roughness/profile measuring device to obtain one-dimensional data arrays, the arrays are subjected to multiresolution analysis (MRA-1) through wavelet transformation to be separated into six frequency components including HHH, HHL, HMH, HML, HLH and HLL to obtain one-dimensional data arrays, the arrays of the HHL are thinned out to be reduced 1/10 to 1/100, thereby producing one-dimensional data arrays, which are then subjected to multiresolution analysis (MRA-2) through wavelet transformation to be separated into six frequency components including LHH, LHL, LMH, LML, LLH and LLL to thereby obtain 12 frequency components in total; and a center-line average roughness (WRa) of the 12 frequency components satisfies relationship (i) below.
    Type: Grant
    Filed: March 17, 2010
    Date of Patent: August 5, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Hidetoshi Kami, Junichi Yamazaki, Yukio Fujiwara, Kazuhiro Egawa
  • Publication number: 20140199620
    Abstract: An electrophotographic photoconductor, including: an electroconductive substrate; and at least a photoconductive layer and a surface layer in this order over the electroconductive substrate, wherein the surface layer includes a resin having no charge transport properties, and first inorganic fine particles, and wherein the first inorganic fine particles are inorganic fine particles having surfaces modified with at least one of a primary amino group and a secondary amino group, and a volume resistivity of the first inorganic fine particles is 1×108 ?·cm or less.
    Type: Application
    Filed: January 15, 2014
    Publication date: July 17, 2014
    Inventors: Toshihiro ISHIDA, Hiroshi IKUNO, Tetsuya TOSHINE, Naohiro TODA, Takafumi IWAMOTO, Kazuhiro EGAWA
  • Publication number: 20140064810
    Abstract: An image forming apparatus includes an electrophotographic photoreceptor; and a cleaning blade. The electrophotographic photoreceptor includes an outermost layer having a ten-point average roughness Rz of from 0.5 to 2.4 ?m and an average interval between concavities and convexities Sm of from 30 to 300 ?m, and the cleaning blade includes a reed-shaped elastic blade having a contact point to the electrophotographic photoreceptor. The contact point includes a substrate; a mixed layer overlying the substrate, including a material forming the substrate and at least one of an acrylic resin and a methacrylic resin and having a thickness not less than 1.0 ?m; and a surface layer overlying the mixed layer, including at least one of an acrylic resin and a methacrylic resin and having a thickness not less than 0.1 ?m.
    Type: Application
    Filed: July 30, 2013
    Publication date: March 6, 2014
    Inventors: Takafumi Iwamoto, Hiroshi Ikuno, Tetsuya Toshine, Kazuhiro Egawa, Toshihiro Ishida, Yohta Sakon, Masahiro Ohmori, Naohiro Toda
  • Patent number: 8597863
    Abstract: An electrophotographic photoreceptor including a conductive substrate, a photosensitive layer, and a cross-linked resin surface layer comprising a cross-linked resin having a charge transport structure, which satisfies the following inequations: 0.01<WRa(LLH)<0.04??(1-1) 0.01<WRa(LML)<0.04??(1-2) 0.01<WRa(LMH)<0.04??(1-3) 0.01<WRa(LHL)<0.04??(1-4) WRa(LHL)>WRa(LHH)??(2-1) WRa(LHL)>WRa(HLH)??(2-2) WRa(LHL)>WRa(HML)??(2-3) WRa(LHL)>WRa(HMH)??(2-4) WRa(LHL)>WRa(HHL)??(2-5) WRa(LHL)>WRa(HHH)??(2-6) wherein WRa (?m) represents an arithmetic average roughness according to JIS-B0601:2001 of frequency components that are obtained by subjecting a one-dimensional data array of a surface profile of the electrophotographic photoreceptor to a wavelet transformation multiresolution analysis.
    Type: Grant
    Filed: June 15, 2010
    Date of Patent: December 3, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Hidetoshi Kami, Yukio Fujiwara, Kazuhiro Egawa
  • Patent number: 8557487
    Abstract: To provide an electrophotographic photoconductor including: a conductive substrate; a photosensitive layer; and a surface layer having grooves which do not intersect each other, the photosensitive layer and the surface layer being laid over the conductive substrate, wherein the grooves each have a width of 60 ?m to 100 ?m and a depth of 0.2 ?m to 2 ?m, wherein the standard deviation of the depths of the grooves is 1/10 or less of the average value of the depths of the grooves measured at any four places, and wherein the grooves are formed in a direction which diagonally crosses a main scanning direction and a sub-scanning direction of the electrophotographic photoconductor.
    Type: Grant
    Filed: September 28, 2010
    Date of Patent: October 15, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Hidetoshi Kami, Kazuhiro Egawa
  • Patent number: 8543037
    Abstract: The image forming apparatus includes a photoreceptor bearing an electrostatic image; a developing device developing the electrostatic image with a developer including a toner to form a toner image on the photoreceptor; a transferring device transferring the toner image onto a receiving material; and a cleaning device having a cleaning blade cleaning the surface of the photoreceptor. The photoreceptor includes an electroconductive substrate, a photosensitive layer and an outermost layer having projected portions thereon. The outermost layer and projected portions include the same crosslinked charge transport material. The outermost layer has a surface roughness property such that the number of projected portions having height greater than Rz/2 is from 40 to 90 in a length of 12 mm, wherein Rz represents ten-point mean roughness of the outermost layer. The tip of the cleaning blade is contacted with the photoreceptor at a linear pressure of from 80 g/cm to 150 g/cm.
    Type: Grant
    Filed: November 2, 2009
    Date of Patent: September 24, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Kazuhiro Egawa, Yukio Fujiwara, Hidetoshi Kami, Kohichi Ohshima
  • Publication number: 20130244150
    Abstract: An electrophotographic photoreceptor, including an electroconductive substrate; a photosensitive layer overlying the electroconductive substrate; and a surface layer overlying the photosensitive layer, wherein the surface layer includes a resin having no charge transportability; and an inorganic particulate material, wherein the inorganic particulate material is a zinc oxide doped with a boron group, and wherein the electrophotographic photoreceptor has a surface specific resistivity (R1) not less than 1013 ?/cm2 when the surface layer has an electric field intensity of 1×104 V/cm, and a ratio (R1/R15) of the surface specific resistivity (R1) to a surface specific resistivity (R15) when the surface layer has an electric field intensity of 1.5×105 V/cm of from 100 to 5,000.
    Type: Application
    Filed: March 5, 2013
    Publication date: September 19, 2013
    Inventors: Tetsuya Toshine, Hiroshi Ikuno, Naohiro Toda, Takafumi Iwamoto, Kazuhiro Egawa, Toshihiro Ishida
  • Publication number: 20130243506
    Abstract: An image forming apparatus including at least a photoreceptor; and a cleaning blade formed of a strip-shaped elastic blade to contact an edge line to the surface of the photoreceptor, wherein the photoreceptor includes a surface layer comprising a particulate material, and the edge line of the cleaning blade includes a substrate of the elastic blade; a mixed layer having a thickness not less than 1.0 ?m, formed of the substrate and at least one of an acrylic resin and a methacrylic resin, located at the surface of the substrate; and a surface layer having a thickness not less than 0.1 ?m, formed of at least one of an acrylic resin and a methacrylic resin, located on the surface of the substrate.
    Type: Application
    Filed: January 29, 2013
    Publication date: September 19, 2013
    Applicant: RICOH COMPANY, LTD.
    Inventors: Hiroshi Ikuno, Yohta Sakon, Masahiro Ohmori, Kazuhiro Egawa, Tetsuya Toshine
  • Patent number: 8512924
    Abstract: An electrophotographic photoreceptor, including an electroconductive substrate; a photosensitive layer; a crosslinked surface layer comprising ?-alumina and tin oxide, wherein a first one-dimensional data array obtained from measuring a concavo-convex shape of the surface of the photoreceptor is subjected to a wavelet conversion to be separated into 6 frequency components, the one-dimensional data array of the lowest frequency component is further thinned so as to have 1/40 data arrays to obtain a second one-dimensional data array, the second one-dimensional data array is further subjected to the wavelet conversion to be separated into additional 6 frequency components, and wherein when relationships between respective arithmetic average roughness (WRa) (y-axis) of the 12 frequency components and the frequency components (x-axis) are graphed, at least WRa (214 to 551 ?m) and WRa (26 to 106 ?m) have a folding point or a maximum point.
    Type: Grant
    Filed: February 2, 2011
    Date of Patent: August 20, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Hidetoshi Kami, Kazuhiro Egawa, Yukio Fujiwara
  • Patent number: 8420284
    Abstract: An electrophotographic photoreceptor, including an electroconductive substrate; a photosensitive layer, located overlying the electroconductive substrate; and an outermost layer comprising a convexity, wherein each of the outermost layer and the convexity includes a crosslinked body including a structural unit having a same charge transportable structure, and wherein the number of convexity having a height not less than ½×RzJIS is from 30 to 300 in a measurement length of 12 mm, wherein RzJIS is an average of ten-point mean roughness specified in JIS B0601 of 2001 and measured at least 4 random positions in an area the outermost layer is formed on, and wherein the height of the convexity is a distance from the deepest valley to a top of the convexity in the measurement length of 12 mm.
    Type: Grant
    Filed: December 18, 2009
    Date of Patent: April 16, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Kohichi Ohshima, Hidetoshi Kami, Yukio Fujiwara, Kazuhiro Egawa