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: 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
  • Patent number: 8293439
    Abstract: An electrophotographic photoreceptor including a conductive substrate, a photosensitive layer, and a surface layer, which satisfies the following inequations: 0.005<WRa(LMH)<0.03??(i) 0.010<WRa(LHH)<0.03??(ii) 0.005<WRa(LML)<0.20??(iii) WRa(LLH)>WRa(LMH)??(iv) WRa(LLH)>WRa(LHH)??(v) wherein WRa (?m) represents a center-line average roughness of frequency components LHH, LHL, LMH, LML, LLH, and LLL that are obtained by subjecting a one-dimensional data array of a surface profile of the electrophotographic photoreceptor to wavelet transformation multiresolution analysis so as to be separated into 6 frequency components; thinning a one-dimensional data array of the lowest frequency component so that the number of data array is reduced to 1/40; and subjecting the thinned one-dimensional data array to wavelet transformation multiresolution analysis so as to be separated into the 6 frequency components LHH, LHL, LMH, LML, LLH, and LLL.
    Type: Grant
    Filed: March 12, 2010
    Date of Patent: October 23, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Yukio Fujiwara, Hidetoshi Kami, Kazuhiro Egawa, Shinji Nohsho, Mayumi Yoshihara, Mihoko Matsumoto, Kohsuke Yamamoto
  • Patent number: 8247143
    Abstract: A photoreceptor including an electroconductive substrate, a photosensitive layer located overlying the electroconductive substrate, and a surface layer located overlying the photosensitive layer, wherein the surface layer is a cross linked surface layer comprising filler particulates on which linear scar is formed along the circumference direction, and the filler particulates form concave portions on a groove formed by the linear scar, and wherein the ten point average roughness Rz along the direction of the rotation axis of the photoreceptor measured on the circumference surface thereof is from 0.17 to 2.00 ?m and the average distance Sm of concavities and convexities along the direction of the rotation axis of the photoreceptor measured on the circumference surface thereof is from 20 to 500 ?m, and the ten point average roughness Rz along the circumference direction of the photoreceptor measured on the circumference surface thereof is from 0.13 to 0.
    Type: Grant
    Filed: November 6, 2009
    Date of Patent: August 21, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Kazuhiro Egawa, Yukio Fujiwara, Hidetoshi Kami
  • Patent number: 8170449
    Abstract: An image forming apparatus including an image bearing member which has an electroconductive substrate, a photosensitive layer overlying the electroconductive substrate and a cross-linked resin surface layer overlying the photosensitive layer and bears a latent electrostatic image on the surface thereof, an application device to apply a solid lubricant to the image bearing member; a charging device to charge the surface of the image bearing member, an irradiation device to irradiate the surface of the image bearing member with light to form the latent electrostatic image thereon, a development device to develop the latent electrostatic with toner to obtain a developed image, a transfer device to transfer the developed image to a recording medium, and; a cleaning device to clean the surface of the image bearing member, wherein the cross-linked resin surface layer includes a cross-linked body of trimethylol propane triacrylate and particulates including silicon and an average diameter of agglomeration areas of t
    Type: Grant
    Filed: February 20, 2009
    Date of Patent: May 1, 2012
    Assignee: Ricoh Company Ltd.
    Inventors: Hidetoshi Kami, Yukio Fujiwara, Kazuhiro Egawa
  • Publication number: 20120008984
    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: Application
    Filed: March 17, 2010
    Publication date: January 12, 2012
    Applicant: RICOH COMPANY. LTD.
    Inventors: Hidetoshi Kami, Junichi Yamazaki, Yukio Fujiwara, Kazuhiro Egawa
  • Publication number: 20110200924
    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: Application
    Filed: February 2, 2011
    Publication date: August 18, 2011
    Applicant: RICOH COMPANY, LTD.,
    Inventors: Hidetoshi KAMI, Kazuhiro Egawa, Yukio Fujiwara
  • Publication number: 20110076057
    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: Application
    Filed: September 28, 2010
    Publication date: March 31, 2011
    Inventors: Hidetoshi KAMI, Kazuhiro Egawa
  • Publication number: 20100316423
    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: Application
    Filed: June 15, 2010
    Publication date: December 16, 2010
    Applicant: RICOH COMPANY, LTD.
    Inventors: Hidetoshi Kami, Yukio Fujiwara, Kazuhiro Egawa
  • Publication number: 20100232831
    Abstract: An electrophotographic photoreceptor including a conductive substrate, a photosensitive layer, and a surface layer, which satisfies the following inequations: 0.005<WRa(LMH)<0.03??(i) 0.010<WRa(LHH)<0.03??(ii) 0.005<WRa(LML)<0.20??(iii) WRa(LLH)>WRa(LMH)??(iv) WRa(LLH)>WRa(LHH)??(v) wherein WRa (?m) represents a center-line average roughness of frequency components LHH, LHL, LMH, LML, LLH, and LLL that are obtained by subjecting a one-dimensional data array of a surface profile of the electrophotographic photoreceptor to wavelet transformation multiresolution analysis so as to be separated into 6 frequency components; thinning a one-dimensional data array of the lowest frequency component so that the number of data array is reduced to 1/40; and subjecting the thinned one-dimensional data array to wavelet transformation multiresolution analysis so as to be separated into the 6 frequency components LHH, LHL, LMH, LML, LLH, and LLL.
    Type: Application
    Filed: March 12, 2010
    Publication date: September 16, 2010
    Applicant: RICOH COMPANY, LTD.
    Inventors: Yukio Fujiwara, Hidetoshi Kami, Kazuhiro Egawa, Shinji Nohsho, Mayumi Yoshihara, Mihoko Matsumoto, Kohsuke Yamamoto
  • Publication number: 20100172670
    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: Application
    Filed: December 18, 2009
    Publication date: July 8, 2010
    Applicant: RICOH COMPANY, LTD.
    Inventors: Kohichi OHSHIMA, Hidetoshi Kami, Yukio Fujiwara, Kazuhiro Egawa
  • Publication number: 20100124712
    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: Application
    Filed: November 2, 2009
    Publication date: May 20, 2010
    Applicant: RICOH COMPANY, LTD.
    Inventors: Kazuhiro EGAWA, Yukio Fujiwara, Hidetoshi Kami, Kohichi Ohshima
  • Publication number: 20100119260
    Abstract: A photoreceptor including an electroconductive substrate, a photosensitive layer located overlying the electroconductive substrate, and a surface layer located overlying the photosensitive layer, wherein the surface layer is a cross linked surface layer comprising filler particulates on which linear scar is formed along the circumference direction, and the filler particulates form concave portions on a groove formed by the linear scar, and wherein the ten point average roughness Rz along the direction of the rotation axis of the photoreceptor measured on the circumference surface thereof is from 0.17 to 2.00 ?m and the average distance Sm of concavities and convexities along the direction of the rotation axis of the photoreceptor measured on the circumference surface thereof is from 20 to 500 ?m, and the ten point average roughness Rz along the circumference direction of the photoreceptor measured on the circumference surface thereof is from 0.13 to 0.
    Type: Application
    Filed: November 6, 2009
    Publication date: May 13, 2010
    Applicant: RICOH COMPANY, LTD.
    Inventors: Kazuhiro EGAWA, Yukio FUJIWARA, Hidetoshi KAMI