Patents by Inventor Masayuki Sakamoto

Masayuki Sakamoto 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: 6814118
    Abstract: A pneumatic tire including a carcass containing a ply of cords defining the innermost reinforcing cord layer extending between bead portions, and an airtight layer disposed inside the cords of the carcass ply along the inner surface of the tire, covering substantially the entire inner surface of the tire, wherein the airtight layer is made of air-impermeable rubber including at least 10 weight % of halogenated butyl rubber and/or halogenated isobutylene-paramethyl styrene copolymer in its rubber base, and the thickness of the airtight layer measured from the inner surface of the tire to the cords of the carcass ply is in a range of from 0.2 to 0.7 mm.
    Type: Grant
    Filed: October 2, 2001
    Date of Patent: November 9, 2004
    Assignee: Sumitomo Rubber Industries, Ltd.
    Inventors: Yasuhiro Narahara, Takuji Kusumoto, Yoshiyuki Kawai, Atsushi Yamakage, Yutaka Kuroda, Masayuki Sakamoto, Toru Nishikawa
  • Patent number: 6775497
    Abstract: In the present invention, a filler element 20 formed of a viscoelastic material with a compressive residual strain of 10% or less and a 25% compressive load of 1 kg/cm2, having a specific shape, is mounted in a drum-shaped electrophotographic photosensitive body (photosensitive drum) 10. The filler element 20 has a sufficient restoring force when deformed, so that it can be fixed to position without an adhesive. Also, the filler element 20 is not moved by vibration or shock during repeated use, and good anti-vibration effect can be maintained.
    Type: Grant
    Filed: March 27, 2003
    Date of Patent: August 10, 2004
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Hiroshi Sugimura, Koichi Toriyama, Mikio Kakui, Rikiya Matsuo, Hisayuki Utsumi, Masanori Matsumoto, Masayuki Sakamoto
  • Patent number: 6717677
    Abstract: It is an object of the invention to inspect defects of a film formed on a relatively rough surface of a substrate by the light interference method. A substrate on which a film is formed is irradiated with light of a longer wavelength than the surface roughness Rmax or Rz of the substrate to obtain interference fringes to inspect defects of the film formed on the substrate. Especially, it is preferable that when the surface roughness Rmax or Rz is 0.5 &mgr;m or more, the substrate is irradiated with light of a wavelength beyond a little longer wavelength than the surface roughness Rmax or Rz. The surface of the substrate is subjected to a cutting process. Specifically, it is possible to inspect defects of the electric charge generation layer, electric charge transport layer, or undercoat layer of an electrophotographic photoreceptor. This photoreceptor is mounted in a digital copier or printer. Further, monochromatic light is preferably applied.
    Type: Grant
    Filed: September 17, 2002
    Date of Patent: April 6, 2004
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Sayaka Fujita, Yoichi Takesawa, Yoshihide Shimoda, Tatsuhiro Morita, Rikiya Matsuo, Masayuki Sakamoto, Koichi Toriyama
  • Publication number: 20040053151
    Abstract: The object of the invention is to prevent interference fringes of images and allow precise measurement of the thickness of a layer by the optical interferometry by limiting the surface roughness of a conductive substrate. The surface roughness of the conductive substrate provided in an electrophotographic photoreceptor is such that the maximum peak-to-valley roughness height (Ry)=0.8 to 1.4 &mgr;m, the centerline average roughness (Ra)=0.10 to 0.15 &mgr;m, the ten-point average roughness (Rz)=0.7 to 1.3 &mgr;m, the average peak-to-peak distance (Sm)=5 to 30 &mgr;m, and the peak count Pc=60 to 100. In such an electrophotographic photoreceptor, light for exposure can be scattered to an appropriate extent, so that interference fringes can be prevented, and an interference pattern is formed during measurement of the thickness of the photosensitive layer by the optical interferometry so that the thickness of the layer can be measured with a high precision.
    Type: Application
    Filed: July 28, 2003
    Publication date: March 18, 2004
    Inventors: Masaki Hashimoto, Kazushige Morita, Mikio Kakui, Yuji Tanaka, Masayuki Sakamoto
  • Patent number: 6696214
    Abstract: The invention provides an electrophotographic photoreceptor, in which suppression of image defects and high sensitivity are compatible, and a method for production thereof. The invention also provides a coating fluid for forming a photosensitive layer and a method for production thereof, as well as an image-forming apparatus using said electrophoto-graphic photoreceptor. Briefly, the electrophoto-graphic photoreceptors may be constructed by forming an undercoating layer on a conductive support, and then forming a photosensitive layer on the undercoating layer. The undercoating layer contains titanium oxide particles in at least either needle shape or dendrite shape. The photosensitive layer contains an electric charge-generating material of which the primary particle size and cohesive particle size are in a range of 0.01 &mgr;m-10 &mgr;m. Accordingly, in the electrophotographic photoreceptors, it is possible to maintain high sensitivity and excellent durability and to form an image with no defect.
    Type: Grant
    Filed: January 6, 2003
    Date of Patent: February 24, 2004
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Satoshi Katayama, Mikio Kakui, Masayuki Sakamoto, Tatsuhiro Morita, Sayaka Fujita, Tadashi Nakamura
  • Publication number: 20030231900
    Abstract: A vibration insulating member fitting method includes the steps of: positioning and wrapping a sheet-like vibration insulating member 2 around a shaft 3 having an air suction/exhaust portion 5; holding the sheet-like vibration insulating member 2 onto the shaft 3 by air suction; and inserting the shaft 3 that sucks the sheet-like vibration insulating member 2 by the air suction into a hollow cylinder 13 of a photosensitive drum 1 to stop the air suction, causing the sheet-like vibration insulating member 2 to be tightly fitted onto the inner wall surface of the photosensitive drum 1 by a restoring force of the sheet-like vibration insulating member 2.
    Type: Application
    Filed: May 22, 2003
    Publication date: December 18, 2003
    Inventors: Koichi Toriyama, Rikiya Matsuo, Mikio Kakui, Hiroshi Sugimura, Masanori Matsumoto, Masayuki Sakamoto
  • Publication number: 20030198483
    Abstract: In the present invention, a filler element 20 formed of a viscoelastic material with a compressive residual strain of 10% or less and a 25% compressive load of 1 kg/cm2, having a specific shape, is mounted in a drum-shaped electrophotographic photosensitive body (photosensitive drum) 10. The filler element 20 has a sufficient restoring force when deformed, so that it can be fixed to position without an adhesive. Also, the filler element 20 is not moved by vibration or shock during repeated use, and good anti-vibration effect can be maintained.
    Type: Application
    Filed: March 27, 2003
    Publication date: October 23, 2003
    Inventors: Hiroshi Sugimura, Koichi Toriyama, Mikio Kakui, Rikiya Matsuo, Hisayuki Utsumi, Masanori Matsumoto, Masayuki Sakamoto
  • Publication number: 20030175605
    Abstract: The invention provides an electrophotographic photoreceptor, in which suppression of image defects and high sensitivity are compatible, and a method for production thereof. The invention also provides a coating fluid for forming a photosensitive layer and a method for production thereof, as well as an image-forming apparatus using said electrophoto-graphic photoreceptor. Briefly, the electrophoto-graphic photoreceptors may be constructed by forming an undercoating layer on a conductive support, and then forming a photosensitive layer on the undercoating layer. The undercoating layer contains titanium oxide particles in at least either needle shape or dendrite shape. The photosensitive layer contains an electric charge-generating material of which the primary particle size and cohesive particle size are in a range of 0.01 &mgr;m-10 &mgr;m. Accordingly, in the electrophotographic photoreceptors, it is possible to maintain high sensitivity and excellent durability and to form an image with no defect.
    Type: Application
    Filed: January 6, 2003
    Publication date: September 18, 2003
    Applicant: Sharp Kabushiki Kaisha
    Inventors: Satoshi Katayama, Mikio Kakui, Masayuki Sakamoto, Tatsuhiro Morita, Sayaka Fujita, Tadashi Nakamura
  • Patent number: 6573105
    Abstract: A test method for a coating liquid for an electrophotographic photoconductor includes calculating a peak area ratio of a component to be analyzed in a coating liquid by pyrolysis gas chromatography, and comparing the peak area ratio with a pre-obtained peak area ratio of the component in a reference coating liquid having a known content of the component, to determine the ratio and/or content of the component in the coating liquid. A control method for controlling a coating liquid based on the test result as obtained is also provided.
    Type: Grant
    Filed: June 6, 2000
    Date of Patent: June 3, 2003
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Tomoko Kanazawa, Yoshihide Shimoda, Sayaka Fujita, Tadashi Nakamura, Masayuki Sakamoto, Tatsuhiro Morita
  • Publication number: 20030073014
    Abstract: An object of the invention is to provide a multi-layered type electrophotographic photoreceptor in which a low-cost porthole tube is used as an electrically conductive support, and an electrophotographic apparatus using the electrophotographic photoreceptor. In the electrophotographic photoreceptor having the multi-layered type photosensitive layer, the porthole tube is used as the electrically conductive support, and an undercoat layer containing titanium oxide and a polyamide resin is provided between the porthole tube and the photosensitive layer.
    Type: Application
    Filed: March 26, 2002
    Publication date: April 17, 2003
    Inventors: Sayaka Fujita, Masanori Matsumoto, Koichi Toriyama, Satoshi Katayama, Masayuki Sakamoto, Akihiko Kawahara
  • Publication number: 20030035110
    Abstract: It is an object of the invention to inspect defects of a film formed on a relatively rough surface of a substrate by the light interference method. A substrate on which a film is formed is irradiated with light of a longer wavelength than the surface roughness Rmax or Rz of the substrate to obtain interference fringes to inspect defects of the film formed on the substrate. Especially, it is preferable that when the surface roughness Rmax or Rz is 0.5 &mgr;m or more, the substrate is irradiated with light of a wavelength beyond a little longer wavelength than the surface roughness Rmax or Rz. The surface of the substrate is subjected to a cutting process. Specifically, it is possible to inspect defects of the electric charge generation layer, electric charge transport layer, or undercoat layer of an electrophotographic photoreceptor. This photoreceptor is mounted in a digital copier or printer. Further, monochromatic light is preferably applied.
    Type: Application
    Filed: September 17, 2002
    Publication date: February 20, 2003
    Applicant: Sharp Kabushiki Kaisha
    Inventors: Sayaka Fujita, Yoichi Takesawa, Yoshihide Shimoda, Tatsuhiro Morita, Rikiya Matsuo, Masayuki Sakamoto, Koichi Toriyama
  • Patent number: 6491081
    Abstract: A method of manufacturing a radial tire is disclosed, wherein a tread ring is formed separately from a tier main body by the sue of a tread ring forming apparatus. The radial tire comprises a belt having a camber and a band wound thereon. The tread ring is an annular assembly of a raw belt, a raw band wound thereon and a raw tread rubber. The tread ring forming apparatus comprising a belt drum made up of segments defining the drum circumference. In a cross section including the belt drum axis, the radially outer surface of each segment is a straight line parallel to the axis. In a cross section normal to the belt drum axis, the radiallly outer surface is an arc having one radius substantially equal to one half of the drum diameter, but the drum circumference is decreased in the belt edge portion than the central portion by increasing gaps between the segments.
    Type: Grant
    Filed: April 20, 2001
    Date of Patent: December 10, 2002
    Assignee: Sumitomo Rubber Industries, Ltd.
    Inventors: Yutaka Kuroda, Masayuki Sakamoto, Toshihiko Omokawa, Kazuya Suzuki
  • Patent number: 6418993
    Abstract: A pneumatic tire is provided in at least one of sidewall portions with a wheelrim protector which overhangs a flange of a wheelrim and protrudes axially outwardly from the axially outer end of the flange, the wheelrim protector is provided with at least one circumferential slit around the axis of the tire. In case of a slit extending continuously in the tire circumferential direction, the slit can be formed in a wedge-shaped cross sectional shape. In case of discontinuous slits, the slits are arranged around the tire axis and inclined with respect to the adjacent carcass cords at 45 to 80 degrees.
    Type: Grant
    Filed: August 31, 1999
    Date of Patent: July 16, 2002
    Assignee: Sumitomo Rubber Industries, Ltd.
    Inventors: Masayuki Sakamoto, Susumu Tanaka, Hiroshi Matsui
  • Publication number: 20020066512
    Abstract: A pneumatic tire comprising a carcass comprising a ply of cords defining the innermost reinforcing cord layer extending between bead portions, and an airtight layer disposed inside the cords of the carcass ply along the inner surface of the tire, covering the substantially entire inner surface of the tire, wherein the airtight layer is made of air-impermeable rubber including at least 10 weight % of halogenated butyl rubber and/or halogenated isobutylene-paramethyl styrene copolymer in its rubber base, and a thickness of the airtight layer measured from the inner surface of the tire to the cords of the carcass ply is in a range of from 0.2 to 0.7 mm.
    Type: Application
    Filed: October 2, 2001
    Publication date: June 6, 2002
    Inventors: Yasuhiro Narahara, Takuji Kusumoto, Yoshiyuki Kawai, Atsushi Yamakage, Yutaka Kuroda, Masayuki Sakamoto, Toru Nishikawa
  • Patent number: 6398533
    Abstract: A mold for a pneumatic tire with an inflatable bladder is disclosed with a pair of axially spaced bead portions each with a bead bottom surface extending from a bead toe toward the axially outside of the tire. The bladder is disposed inside the green tire in the mold and inflated to press the green tire against the inside of the mold. The mold comprises a pair of bead rings and each bead ring is provided with a bead bottom molding face for molding said bead bottom surface. Each bead ring is provided radially inside the bead bottom molding face with a protrusion protruding axially inwardly from the axially inner end of the bead bottom molding face so that the axial extent of the protrusion from the axially inner end of the bead bottom molding face is in the range of from 0.05 to 0.4 times the axial distance between the axially inner ends of the bead molding faces.
    Type: Grant
    Filed: June 29, 2000
    Date of Patent: June 4, 2002
    Assignee: Sumitomo Rubber Industries, Ltd.
    Inventors: Masahiro Hanya, Emiko Yamamoto, Masayuki Sakamoto, Ryo Ono
  • Patent number: 6321806
    Abstract: A pneumatic tire, which is adapted for a standard wheel rim, comprises a tread portion, a pair of sidewall portions, a pair of bead portions, a carcass extending between the bead portions, and a rim flange holder disposed on each side of the tire and protruding axially outwardly so as to overhang a flange of the standard wheel rim. The rim flange holder has a hooking part extending radially inwardly on the axially outside of the flange so as to hook the flange. The radial measurement between the radially outermost point of the flange and the radially innermost point of the hooking part is at least 2 mm, and the rim flange holder is provided with a slit extending axially inwardly from the axial outer surface of the rim flange holder.
    Type: Grant
    Filed: March 17, 2000
    Date of Patent: November 27, 2001
    Assignee: Sumitomo Rubber Industries, Ltd.
    Inventor: Masayuki Sakamoto
  • Publication number: 20010040638
    Abstract: Disclosed is an optical device including an optical member, a memory unit for storing preset driving information about driving of the optical member, a driving unit for driving the optical member, an operation unit having an operation member, and a control unit for performing drive control of the driving unit. The control unit changes the preset driving information in accordance with the operation of the operation unit.
    Type: Application
    Filed: March 29, 2001
    Publication date: November 15, 2001
    Inventors: Kazumasa Yoshikawa, Satoshi Natsume, Masayuki Sakamoto
  • Publication number: 20010020510
    Abstract: A method of manufacturing a radial tire is disclosed, wherein a tread ring is formed separately from a tier main body by the sue of a tread ring forming apparatus. The radial tire comprises a belt having a camber and a band wound thereon. The tread ring is an annular assembly of a raw belt, a raw band wound thereon and a raw tread rubber. The tread ring forming apparatus comprising a belt drum made up of segments defining the drum circumference. In a cross section including the belt drum axis, the radially outer surface of each segment is a straight line parallel to the axis. In a cross section normal to the belt drum axis, the radiallly outer surface is an arc having one radius substantially equal to one half of the drum diameter, but the drum circumference is decreased in the belt edge portion than the central portion by increasing gaps between the segments.
    Type: Application
    Filed: April 20, 2001
    Publication date: September 13, 2001
    Applicant: Sumitomo Rubber Industries, Ltd.
    Inventors: Yutaka Kuroda, Masayuki Sakamoto, Toshihiko Omokawa, Kazuya Suzuki
  • Patent number: 6257290
    Abstract: A pneumatic tire having an aspect ratio of not more than 55% and comprising: an axially protruding rib provided on each side of the tire to overhang a flange of a wheel rim; a carcass extending between bead portions through a tread portion and sidewall portions; a belt disposed radially outside the carcass; a tread rubber disposed radially outside the belt to define the ground contacting surface of the tire; a sidewall rubber disposed on each side of the tire and extending from the tread portion to the rib along the axially outside of the carcass; a clinch rubber disposed on each side of the tire and extending from the bead portion to the rib along the outer surface of the tire; and a wing rubber disposed axially outside the sidewall rubber and extending from the tread rubber to the rib along the outer surface of the tire, the wing rubber being softer than the tread rubber.
    Type: Grant
    Filed: May 26, 1999
    Date of Patent: July 10, 2001
    Assignee: Sumitomo Rubber Industries, Ltd.
    Inventors: Masayuki Sakamoto, Atsushi Yamakage, Kazuya Suzuki
  • Patent number: 6258500
    Abstract: A photosensitive body for electrophotographical use has a conductive base body and a marking area provided thereon. The maximum surface roughness of a photosensitive layer provided right on the marking area is specified not to exceed 2.5 &mgr;m. And also, a ratio of the optical reflective index of the marking area to the optical reflective index of the non-marking area is specified to be in a range of 0.3 to 0.7. In this manner, even when the photosensitive layer is thin (not exceeding 25 &mgr;m), it is possible to prevent problems such as inadequate cleaning and toner falling. Hence, it is possible to offer a photosensitive body for electrophotographical use which can constantly produce high quality copied images.
    Type: Grant
    Filed: October 27, 2000
    Date of Patent: July 10, 2001
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Hideaki Taniguchi, Yasutaka Maeda, Masayuki Sakamoto, Masaya Tsugoshi, Makoto Kurokawa