Patents by Inventor Masanori Kawasumi

Masanori Kawasumi 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: 20060133837
    Abstract: An image forming apparatus that can prevent the generation of filming with the simplest possible configuration even if a plurality of photosensitive member linear velocities are provided and the AC frequency of the charge apparatus is fixed. A charge apparatus that charges by uniformly superimposing on a photosensitive member an alternate current bias voltage with a fixed frequency over a direct current bias voltage as the charge bias voltage; an exposure apparatus that exposes the surface of the charged photosensitive member based on image data, and writes a latent image; a developing apparatus that supplies toner to and makes visible the latent image formed on the surface of the photosensitive member; a transfer apparatus that transfers the visible image on the photosensitive member to a transfer medium; and a cleaning apparatus that cleans the surface of the photosensitive member after transfer.
    Type: Application
    Filed: November 30, 2005
    Publication date: June 22, 2006
    Inventors: Eiji Shimojo, Haruji Mizuishi, Tokuya Ojimi, Masanori Kawasumi, Takuzi Yoneda, Ken Amemiya, Takatsugu Fujishiro, Hiroshi Ono, Toshio Koike, Masami Tomita, Yuji Arai, Takeshi Uchitani
  • Publication number: 20060133834
    Abstract: An image forming apparatus including an image bearing member, a charging member, and a measuring member. The image forming member is configured to bear an image. The charging member is configured to charge a surface of the image bearing member when a direct current bias voltage is added to at least an alternating bias voltage which is applied to the charging member, and has a frequency fc of the alternating bias voltage. The measuring member is configured to measure a potential of the surface of the image bearing member, and has a drive frequency fvsen. The relationship of the frequency fc and the drive frequency fvsen is expressed as fc?fvsen×n and fc×n?fvsen.
    Type: Application
    Filed: November 14, 2005
    Publication date: June 22, 2006
    Inventors: Takuzi Yoneda, Hiroshi Ono, Masanori Kawasumi, Yuji Arai, Toshio Koike, Ken Amemiya, Tokuya Ojimi, Takatsugu Fujishiro, Masami Tomita, Haruji Mizuishi, Hitoshi Ishibashi
  • Patent number: 7065316
    Abstract: A cleaning unit is equipped with a cleaning blade that is in contact with a surface of a photosensitive drum and cleans the surface. A peak temperature of a loss tangent (tan ?) is in a range of 2° C. to ?30° C. when a sine-wave vibration of 10 Hz is applied to the cleaning blade. Moreover, the cleaning unit lowers a coefficient of static friction of the surface of the photosensitive drum that is to be cleaned.
    Type: Grant
    Filed: September 24, 2003
    Date of Patent: June 20, 2006
    Assignee: Ricoh Company, Limited
    Inventors: Masato Yanagida, Atsushi Sampe, Naohiro Kumagai, Toshio Koike, Takeshi Shintani, Masanori Kawasumi, Masami Tomita, Eisaku Murakami, Takeshi Uchitani
  • Patent number: 7062194
    Abstract: A charging device including a charging roller having a metallic cylinder with an elastic layer disposed thereon, and a cleaner for cleaning the surface of the charging roller. The cleaner includes a driving shaft and a cleaning roller rotatably mounted on the driving shaft. The cleaning roller is made of a non-cellular foam resin having a density of from 5 to 15 kg/m3 and a tensile strength of from 1.2 to 2.2 kg/cm2.
    Type: Grant
    Filed: May 12, 2004
    Date of Patent: June 13, 2006
    Assignee: Ricoh Company Limited
    Inventors: Masato Yanagida, Hiroyuki Nagashima, Naohiro Kumagai, Toshio Koike, Atsushi Sampe, Masanori Kawasumi, Eisaku Murakami, Takeshi Uchitani, Masami Tomita, Takeshi Shintani, Tsutomu Yamakami
  • Publication number: 20060115286
    Abstract: An image forming apparatus including an image bearing member configured to bear an electrostatic latent image; a charging device configured to charge the image bearing member by applying a DC voltage overlapped with an AC voltage to the image bearing member; an AC current detector configured to detect an AC current flowing through the image bearing member on a ground side of the image bearing member; a light irradiating device configured to irradiate the charged image bearing member with imagewise light to form the electrostatic latent image on the image bearing member; a developing device configured to develop the electrostatic latent image with a developer comprising a toner to form a toner image on the image bearing member; a transferring device configured to transfer the toner image onto a receiving material; and a cleaning device configured to clean a surface of the image bearing member.
    Type: Application
    Filed: November 28, 2005
    Publication date: June 1, 2006
    Inventors: Takeshi Uchitani, Ken Amemiya, Toshio Koike, Hiroshi Ono, Takatsugu Fujishiro, Tokuya Ojimi, Yuji Arai, Masanori Kawasumi, Takuji Yoneda, Haruji Mizuishi, Masaharu Yokono, Masami Tomita
  • Patent number: 7050741
    Abstract: An imaging apparatus that is capable of realizing good cleaning characteristics and transfer characteristics, and obtaining a high quality image using toner having a high average roundness is provided. The imaging apparatus includes an image carrier, a charge unit, a developing unit, a transfer unit, and a cleaning unit. The transfer unit may directly transfer a toner image onto a recording medium that is carried by a transfer belt, or transfer the toner image onto the transfer belt first to then transfer the toner image onto the recording medium from the transfer belt. The cleaning unit includes a cleaning blade and a brush roller. The toner used in the imaging apparatus has an average roundness ? within a range of 0.93˜0.99, and a friction coefficient ?s of the image carrier satisfies a condition, friction coefficient ?s?3.6?3.3×average roundness ?.
    Type: Grant
    Filed: April 9, 2004
    Date of Patent: May 23, 2006
    Assignee: Ricoh Company, Ltd.
    Inventors: Toshio Koike, Eisaku Murakami, Masato Yanagida, Takeshi Shintani, Naohiro Kumagai, Atsushi Sampe, Masami Tomita, Hiroyuki Nagashima, Masanori Kawasumi, Takeshi Uchitani
  • Patent number: 7024133
    Abstract: An image forming apparatus includes a frame, a plurality of process cartridges, and a guide mounted to the frame. The guide mounted to the frame includes a plurality of guide portions having supporting surfaces arranged at predetermined different heights and on which the plurality of process cartridges are detachably placed, and is configured to guide the plurality of process cartridges placed on the supporting surfaces along a path between respective first positions and respective second positions.
    Type: Grant
    Filed: December 22, 2003
    Date of Patent: April 4, 2006
    Assignee: Ricoh Co., Ltd.
    Inventors: Hiroyuki Nagashima, Atsushi Sampe, Yoshiyuki Kimura, Nobuo Kuwabara, Hiroshi Hosokawa, Hideki Zemba, Wakako Murakami, Yuji Arai, Satoshi Narumi, Kiyonori Tsuda, Ryuta Takeichi, Masanori Kawasumi, Kazuhiko Umemura
  • Publication number: 20060062594
    Abstract: An image forming apparatus having an image support body configured to support a latent image, a charging member configured to provide a substantially uniform charge to a surface of the image support body and a spacer coupled to the charging member and configured to contact the image support body to maintain a gap between the image support body and the charging member. A cleaning part is configured to clean the surface of the image support body after developer is applied to the image support body and transferred to a recording medium. The cleaning part is configured to satisfy the relationship A+B?C, where A is a width of the effective charging area of the charging member that charges a surface of the image support body, B is a total width of the spacer that contacts the image support body, and C is a width of cleaning part that contacts the image support body.
    Type: Application
    Filed: September 13, 2005
    Publication date: March 23, 2006
    Inventors: Masanori Kawasumi, Haruji Mizuishi, Tokuya Ojimi, Toshio Koike, Takeshi Shintani, Yuji Arai, Takuzi Yoneda, Ken Amemiya, Takaaki Tawada, Masami Tomita, Takeshi Uchitani, Nobuo Kuwahara, Hiroyuki Nagashima, Masato Yanagida
  • Publication number: 20060039726
    Abstract: A cleaning device, a process cartridge, an image forming apparatus, and toner to maintain improved cleaning performance for a long time. The cleaning device includes a cleaning blade, a lubricant applying part, and a toner removing part. The cleaning blade is disposed in contact with a surface of an image bearing member. The lubricant applying part coats a solid lubricant on the surface of the image bearing member, and is disposed in an upstream side from the cleaning blade with respect to a rotational direction of the image bearing member. The toner removing part removes toner particles, and is disposed in an upstream side from the lubricant applying part with respect to the rotational direction of the image bearing member.
    Type: Application
    Filed: August 22, 2005
    Publication date: February 23, 2006
    Inventors: Takeshi Shintani, Takuzi Yoneda, Ken Amemiya, Takaaki Tawada, Tokuya Ojimi, Toshio Koike, Yuji Arai, Masanori Kawasumi, Masami Tomita, Hideyo Watanabe, Satoshi Takano, Haruji Mizuishi, Hiroshi Ono, Hiroshi Mizusawa, Satoshi Hatori, Takeshi Tabuchi, Akira Fujimori, Kaoru Yoshino
  • Patent number: 7003255
    Abstract: An image forming process and apparatus, the apparatus including a toner container, a transfer belt below the toner container, a process cartridge below the transfer belt, and an imaging device below the process cartridge. The process cartridge includes a rotating image carrier having an image carrier surface, a brush roller in contact with the image carrier surface, a charging member in contact with the image carrier surface and configured to transfer a charge to the image carrier surface, and a casing including a miler in contact with the image carrier surface and arranged to separate the brush roller from the charging member.
    Type: Grant
    Filed: September 22, 2003
    Date of Patent: February 21, 2006
    Assignee: Ricoh Company, Ltd.
    Inventors: Masanori Kawasumi, Kazuhiko Umemura, Satoshi Narumi, Hiroshi Hosokawa, Takeichi Ryuta, Kiyonori Tsuda, Yuji Arai
  • Publication number: 20050271420
    Abstract: A charging apparatus, process cartridge, and image forming apparatus with which current fluctuation values in the charging current can be suppressed, and image defects caused by filming and the like can be prevented, by specifying a permissible gap fluctuation value by quantitatively ascertaining the relationship between the fluctuation value in charging current and the fluctuation value in the gap between the photosensitive body and the charging roller. In a charging apparatus equipped with a charging roller provided at a minute gap away from a photosensitive body, for performing charging, the relationship Gmax?Gmin?30 (?m) is satisfied when the gap (?m) between the charged side of the photosensitive body and the charging side of the charging roller has a maximum value Gmax (?m) and a minimum value Gmin (?m).
    Type: Application
    Filed: June 3, 2005
    Publication date: December 8, 2005
    Inventors: Yuji Arai, Tokuya Ojimi, Takaaki Tawada, Toshio Koike, Ken Amemiya, Takeshi Shintani, Masanori Kawasumi, Takuzi Yoneda, Masami Tomita, Takeshi Uchitani, Nobuo Kuwabara, Hiroyuki Nagashima, Hiroshi Ono, Takatsugu Fujishiro, Haruji Mizuishi, Masaharu Yokono
  • Publication number: 20050232665
    Abstract: An image forming apparatus is provided having an image carrier, a charging unit, an exposing unit, a developing unit, a transfer unit, a cleaning mechanism, and an application mechanism, in which the developing unit supplies a toner, free from zinc and having an average circularity of at least 0.93, to the latent image to make visible the latent image, and wherein the cleaning mechanism cleans the image carrier, and the application mechanism applies a lubrication agent preferably formed of zinc stearate on the image carrier, such that the zinc amount on the surface of the image carrier after a cleaning process and an application process is from 0.4 to 2.5 atm %.
    Type: Application
    Filed: March 28, 2005
    Publication date: October 20, 2005
    Inventors: Koike Toshio, Ken Amemiya, Masanori Kawasumi, Yuji Arai, Tokuya Ojimi, Takaaki Tawada, Takuzi Yoneda, Takeshi Shintani, Masami Tomita
  • Publication number: 20050232666
    Abstract: An image forming apparatus includes an image bearing member configured to bear an electrostatic latent image on a surface thereof, a developing mechanism configured to develop the electrostatic latent image formed on the surface of the image bearing member into a toner image with toner, a transfer mechanism configured to transfer the toner image from the image bearing member to an image receiver, and a cleaning mechanism including a cleaning blade configured to scrape a residual toner on the surface of the image bearing member after the toner image is transferred to the image receiver, the cleaning blade disposed in contact with the image bearing member and having a JIS-A hardness equal to or more than 70 and a repulsion elasticity equal to or less than 30%, and a friction reducing member configured to reduce a coefficient of friction on the surface of the image bearing member.
    Type: Application
    Filed: April 7, 2005
    Publication date: October 20, 2005
    Inventors: Tokuya Ojimi, Toshio Koike, Takaaki Tawada, Takeshi Shintani, Yuji Arai, Takuzi Yoneda, Masanori Kawasumi, Masami Tomita, Ken Amemiya, Shinichi Kawahara
  • Publication number: 20050226656
    Abstract: An image forming apparatus of the present invention includes a process cartridge including a developing device that includes a developer carrier and a toner storing portion storing toner for replenishment. The developer carrier conveys a developer deposited thereon to a developing zone where the developer carrier faces and image carrier. The developing device feeds the toner from the toner storing portion to the developer carrier or the developer deposited on the developer carrier. A toner container stores toner to be replenished to said the storing section. The process cartridge and toner container each are removably mounted to the apparatus independently of each other. A toner conveying device configured to convey the toner from toner container to toner storing portion by using the weight of the toner is mounted on the image forming apparatus.
    Type: Application
    Filed: September 23, 2003
    Publication date: October 13, 2005
    Inventors: Kiyonori Tsuda, Hiroshi Hosokawa, Masanori Kawasumi, Satoshi Narumi, Ryuta Takeichi, Kazuhiko Umemura, Yuji Arai
  • Publication number: 20050191081
    Abstract: There is provided a cleaning device for an image-forming device configured so as to be capable of preventing the image quality from deteriorating by being able to prevent the deterioration of the charging state caused by deposits of foreign matter without increasing costs. There is also provided a cleaning member that can make contact with the cleaning target-members. The cleaning member has a portion composed of melamine resin foam for making contact with at least the cleaning target members, and the melamine resin foam has an Asker F hardness of 5 to 25 points and a hardness variation of 5 points or less, and is used on the cleaning target members in a state obtained by heat compression from the original shape. The pressing member is furthermore disposed in contact with the cleaning member.
    Type: Application
    Filed: February 8, 2005
    Publication date: September 1, 2005
    Inventors: Takaya Muraishi, Hiromichi Ninomiya, Atsushi Sampe, Yoshiyuki Kimura, Hiroyuki Nagashima, Hiroshi Hosokawa, Ken Amemiya, Toshio Koike, Tokuya Ojimi, Takaaki Tawada, Takeshi Shintani, Yuji Arai, Takuji Yoneda, Masanori Kawasumi, Masami Tomita
  • Publication number: 20050191574
    Abstract: An image forming apparatus performs electrophotographic image forming using a toner and includes an image bearing member configured to bear an electrostatic latent image on a surface thereof, a developing mechanism configured to develop the electrostatic latent image in to a toner image by using a toner, a transfer mechanism configured to transfer the toner image from the image bearing member to an image receiver, a cleaning mechanism including a cleaning blade and configured to remove a residual toner on the image bearing member after toner image is transferred to the image receiver. The toner includes a binder resin and a colorant, forms a toner powder layer, and satisfies an inequality Y??0.05X+0.029, in which “X” expresses a porosity of the toner powder layer after uniformly compressed at a constant force and “Y” expresses a torque value obtained by rotatably sticking a conical rotor into the toner powder layer.
    Type: Application
    Filed: February 18, 2005
    Publication date: September 1, 2005
    Inventors: Toshio Koike, Tokuya Ojimi, Takaaki Tawada, Takeshi Shintani, Yuji Arai, Takuzu Yoneda, Masanori Kawasumi, Masami Tomita, Kazuhiko Umemura, Ken Amemiya
  • Publication number: 20050164108
    Abstract: An lubricant for electrophotography is applied to a latent image carrier that is supplied with toner having a sphericity of 0.94 or more. The lubricant for electrophotography is added with an inorganic additive having the following relationship: 2Y/1000?X?Y/10 where Y is a toner particle size (micrometer), and X is an inorganic additive particle size (micrometer).
    Type: Application
    Filed: December 10, 2004
    Publication date: July 28, 2005
    Inventors: Eisaku Murakami, Masami Tomita, Ken Amemiya, Masato Yanagida, Naohiro Kumagai, Takeshi Shintani, Takaaki Tawada, Yuji Arai, Toshio Koike, Takeshi Tabuchi, Yutaka Takahashi, Takeshi Uchitani, Masanori Kawasumi
  • Publication number: 20050084271
    Abstract: An image forming apparatus includes an image carrier, a charging unit that charges the image carrier, a latent image forming unit that forms a latent image on the image carrier, a developing unit that develops the latent image to form a toner image, a transferring unit that transfers the toner image to a recording medium, a cleaning unit that cleans toner remaining on the image carrier, a lubricant applying unit that applies a solid lubricant to a surface of the image carrier, and a detecting unit that detects whether the image carrier is brand new. The toner has an average roundness of 0.94 or more. The lubricant applying unit is operated when the detecting unit detects that the image carrier is brand new.
    Type: Application
    Filed: August 20, 2004
    Publication date: April 21, 2005
    Inventors: Toshio Koike, Ken Amemiya, Naohiro Kumagai, Masato Yanagida, Masanori Kawasumi, Takeshi Uchitani, Yutaka Takahashi, Yuji Arai, Takaaki Tawada, Masami Tomita, Takeshi Tabuchi, Eisaku Murakami, Takeshi Shintani, Takuji Yoneda
  • Publication number: 20050074264
    Abstract: A cleaning unit includes a cleaning blade that cleans toner on an image carrier and a brush-shaped roller that applies a lubricant of a molded lubricant on the image carrier. The brush-shaped roller is insulative, and delivers the toner cleaned by the cleaning blade to inside of the cleaning unit.
    Type: Application
    Filed: August 20, 2004
    Publication date: April 7, 2005
    Inventors: Ken Amemiya, Masato Yanagida, Naohiro Kumagai, Takeshi Shintani, Takaaki Tawada, Yuji Arai, Toshio Koike, Takuji Yoneda, Takeshi Tabuchi, Yutaka Takahashi, Eisaku Murakami, Takeshi Uchitani, Masami Tomita, Masanori Kawasumi
  • Publication number: 20050036805
    Abstract: An image forming apparatus includes an image bearing member configured to form an electrostatic latent image on a surface thereof, and a separating mechanism configured to separate an irregular charge toner from a residual toner remaining on the surface of the image bearing member after a completion of an image forming process, to provide an extra travel passage to give a time delay to the irregular charge toner, and to return the irregular charge toner with the time delay to the surface of the image bearing member.
    Type: Application
    Filed: June 24, 2004
    Publication date: February 17, 2005
    Inventors: Eisaku Murakami, Toshio Koike, Masato Yanagida, Naohiro Kumagai, Takeshi Shintani, Masanori Kawasumi, Atsushi Sampe, Masami Tomita, Hiroyuki Nagashima, Takeshi Uchitani