Patents by Inventor Akihiko Nakazawa
Akihiko Nakazawa 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: 20020058189Abstract: In an electrophotographic belt member comprising a resin composition, the resin composition contains from 30% by weight to 90% by weight of a thermoplastic resin, from 2% by weight to 30% by weight of a compound selected from the group consisting of a polyether-ester amide, a polyether ester and a polyether amide, from 0% by weight to 5% by weight of an electrolyte, and from 2% by weight to 50% by weight of an insulating filler. Also disclosed are a process for producing the electrophotographic belt member, and an electrophotographic apparatus having the electrophotographic belt member.Type: ApplicationFiled: September 18, 2001Publication date: May 16, 2002Inventors: Atsushi Tanaka, Akihiko Nakazawa, Tsunenori Ashibe, Takashi Kusaba, Hidekazu Matsuda
-
Publication number: 20020054971Abstract: A process is disclosed producing an intermediate transfer member used in an image-forming apparatus in which an image formed on a first image-bearing member is transferred to a second image-bearing member. The process has the steps of melt-extruding an extrusion material from a circular die by means of an extruder and thereafter making the same into a desired shape to obtain a cylindrical extruded product, and forming the resultant cylindrical extruded product into the intermediate transfer member. The cylindrical extruded product contains a thermoplastic resin and an ion-conductive resistance control agent, and a ratio of the diameter of the intermediate transfer member obtained to the die diameter of the circular die is from 0.5 to 4.0. Also disclosed are an intermediate transfer member obtained by the production process, and an intermediate transfer member having the intermediate transfer member.Type: ApplicationFiled: September 14, 2001Publication date: May 9, 2002Inventors: Minoru Shimojo, Hiroyuki Kobayashi, Akihiko Nakazawa, Akira Shimada, Atsushi Tanaka, Tsunenori Ashibe, Takashi Kusaba, Hidekazu Matsuda
-
Publication number: 20020006573Abstract: A process for producing a belt-shaped transfer member to be used in an image-forming apparatus is disclosed in which a toner image held on a latent-image-bearing member is electrostatically transferred under application of a voltage via the belt-shaped transfer member. The process comprises the steps of melt-extruding a material containing a thermoplastic resin, from a circular die into a cylindrical film; forming the resultant cylindrical film by stretching in such a way that the cylindrical film comes to have a thickness smaller than the die gap of the circular die; and cutting the cylindrical film thus formed, into a seamless belt having a thickness of from 40 &mgr;m to 300 &mgr;m and a modulus in tension of 600 MPa or higher. Also disclosed is a belt-shaped transfer member produced by this process.Type: ApplicationFiled: December 29, 2000Publication date: January 17, 2002Inventors: Akihiko Nakazawa, Hiroyuki Kobayashi, Minoru Shimojo, Akira Shimada, Atsushi Tanaka, Tsunenori Ashibe, Takashi Kusaba, Hidekazu Matsuda
-
Patent number: 6303072Abstract: A process for producing an endless belt includes melt-extruding an extrusion material into a cylinder by means of an extruder, where the extrusion material has a tensile break strength of 400 kgf/cm2 or above and a breaking extension of from 3.0% to 250%, and where the extrusion material is extruded in an extrusion ratio of from 1.05 to 2.80 while a gas is blown into the inside of the melt-extruded cylindrical product.Type: GrantFiled: July 27, 1999Date of Patent: October 16, 2001Assignee: Canon Kabushiki KaishaInventors: Hiroyuki Kobayashi, Minoru Shimojo, Akihiko Nakazawa, Akira Shimada, Atsushi Tanaka, Tsunenori Ashibe, Takashi Kusaba, Hidekazu Matsuda
-
Patent number: 6278858Abstract: An image performing apparatus and method for forming an image using a first image holding member and an intermediate transfer member for holding by primary transfer a toner image formed on the first image holder and for retransferring by secondary transfer the transferred toner image onto a second image holding member, wherein a contact angle between a surface layer of an intermediate transfer member and water is 50° to 120° and transfer-promoting particles are loaded onto the surface layer.Type: GrantFiled: May 19, 1998Date of Patent: August 21, 2001Assignee: Canon Kabushiki KaishaInventors: Akihiko Nakazawa, Toshio Takamori, Takashi Kusaba
-
Patent number: 6144830Abstract: An intermediate transfer member is formed by at least a base layer and a surface layer. The base layer is formed by epichlorohydrin rubber and acrylonitrile-butadiene rubber mixed in a certain weight ratio (preferably 1:9 to 9:1). The surface layer is formed by urethane resin or elastomer and a fluorine-containing compound powder. The fluorine-containing compound powder may preferably be contained in an amount of 20-80 wt. % based on the surface layer. The intermediate transfer member is suitable for full-color image formation by electrophotography and is effective in improving a transfer performance and providing clear images without causing transfer failure even in repetitive use for a long period.Type: GrantFiled: January 9, 1997Date of Patent: November 7, 2000Assignee: Canon Kabushiki KaishaInventors: Takashi Kusaba, Hiroyuki Kobayashi, Minoru Shimojo, Akihiko Nakazawa, Akira Shimada, Atsushi Tanaka, Tsunenori Ashibe
-
Patent number: 5991566Abstract: An image forming apparatus and method includes a first image-bearing member, a latent image-forming device for forming an electrostatic latent image on the first image-bearing member, developer for developing the electrostatic latent image with a toner to form a toner image, an intermediate transfer member for receiving the toner image by primary transfer and transferring the toner image onto a second image-bearing member by secondary transfer, a charging member for charging a residual toner remaining on the intermediate transfer member after the secondary transfer, and a recovery member for recovering the charged residual toner at a recovery position by voltage application. The intermediate transfer member exhibits a charging characteristic such that it has a surface potential of at most 500 volts as an absolute value at the recovery position.Type: GrantFiled: February 24, 1998Date of Patent: November 23, 1999Assignee: Canon Kabushiki KaishaInventors: Atsushi Tanaka, Hiroyuki Kobayashi, Akihiko Nakazawa, Tsunenori Ashibe, Takashi Kusaba
-
Patent number: 5950058Abstract: This invention relates to an image forming apparatus comprises an image bearing member for bearing a toner image, an intermediate transfer member for allowing the toner image on the image bearing member to undergo electrostatic primary transfer thereto at the position of primary transfer and then enabling the toner image deposited thereon to undergo secondary transfer to a transfer material, and a charging member for charging a residual toner remaining on the intermediate transfer member after the second transfer of the toner image on the intermediate transfer member to a transfer material and consequently causing the residual toner charged by the charging member to be transferred at the position of primary transfer to the image bearing member. Wherein the sum of the surface roughness, Rz, of the intermediate transfer member and that of the charging member is not less than 1 .mu.m and not more than 50 .mu.m.Type: GrantFiled: February 20, 1998Date of Patent: September 7, 1999Assignee: Canon Kabushiki KaishaInventors: Takashi Kusaba, Akihiko Nakazawa, Toshio Takamori
-
Image forming method employing toner containing higher and lower molecular weight polymer components
Patent number: 5942366Abstract: An electrophotographic toner composition suitable for heat-fixation and showing good storage characteristics is constituted by polymer components, a colorant and a metal-containing organic compound. The toner composition shows a melt index (at 125.degree. C., 10 kg-load) of 5-25 g/10 min., and the polymer components are characterized by (a) containing substantially no THF (tetrahydrofuran)-insoluble content, (b) including a THF-soluble content thereof providing a GPC (gel permeation chromatography) chromatogram showing i) a main peak in a molecular weight region of 2.times.10.sup.3 -3.times.10.sup.4, and a sub-peak or shoulder in a molecular weight region of at least 10.sup.5, and ii) an areal percentage of 3-10% in a molecular weight region of at least 10.sup.6, and (c) including a polymer component (H) in a molecular weight region of at least 10.sup.5 obtained by polymerization using a polyfunctional polymerization initiator and a mono-functional polymerization initiator.Type: GrantFiled: February 12, 1998Date of Patent: August 24, 1999Assignee: Canon Kabushiki KaishaInventors: Manabu Ohno, Hiroyuki Suematsu, Akihiko Nakazawa, Nobuyuki Okubo, Shunji Suzuki -
Patent number: 5854365Abstract: The present invention relates a toner for developing electrostatic images, comprising: a resin composition, which contains a binder resin and low molecular weight wax, and a coloring agent, wherein the binder resin does not substantially contain insoluble tetrahydrofuran (THF) component, its chromatograph measured with soluble tetrahydrofuran (THF) component has a main peak in a region of a molecular weight of 2,000 to 30,000 and a subpeak or a shoulder in a high molecular weight region of a molecular weight of 100,000 or more, a ratio of weight average molecular weight (Mw)/number average molecular weight (Mn) thereof is 30 or more, the high molecular weight region has a crosslinking monomer unit as a component monomer unit and the binder resin contains high molecular weight polymer having a Mw of 1,200,000 or more polymerized by using both polyfunctional initiator and a mono-functional initiator. Moreover, the present invention relates to a method of manufacturing a resin composition for producing a toner.Type: GrantFiled: December 19, 1995Date of Patent: December 29, 1998Assignee: Canon Kabushiki KaishaInventors: Manabu Ohno, Akihiko Nakazawa, Nobuyuki Okubo, Shunji Suzuki, Hiroyuki Suematsu, Masayoshi Kato
-
Patent number: 5853938Abstract: A toner for developing an electrostatic image has colorant-containing resin particles and amorphous fine titanium oxide particles comprising primary particles having an average particle diameter of from 1 m.mu. to 200 m.mu..Type: GrantFiled: January 21, 1994Date of Patent: December 29, 1998Assignee: Canon Kabushiki KaishaInventors: Akihiko Nakazawa, Kenji Okado
-
Patent number: 5842080Abstract: An image forming apparatus includes: a first image-bearing member, an intermediate transfer member for receiving an image formed on the first image-bearing member and transferring the image onto a second image-bearing member, pattern-forming means for forming a prescribed pattern on the intermediate transfer member, density detection means for detecting a density of the pattern, and control means for controlling image forming conditions based on the detected density. The intermediate transfer member is set to have a reflectance of 10-70% for light having a wavelength in the range of 700-1500 nm at least in a region thereof for forming the prescribed pattern. As a result, the pattern density detection is suitably performed on the intermediate transfer member for all of yellow, magenta cyan and black, and the detected density data is used for controlling the image forming conditions.Type: GrantFiled: March 7, 1997Date of Patent: November 24, 1998Assignee: Canon Kabushiki KaishaInventors: Tsunenori Ashibe, Hiroyuki Kobayashi, Akihiko Nakazawa, Atsushi Tanaka, Takashi Kusaba
-
Patent number: 5752130Abstract: An image forming apparatus includes a first image-bearing member, latent image-forming unit for forming an electrostatic latent image on the first image-bearing member, developer for developing the electrostatic latent image with a toner to form a toner image, an intermediate transfer member for receiving the toner image by primary transfer and transferring the toner image onto a second image-bearing member by secondary transfer, a charging member for charging a residual toner remaining on the intermediate transfer member after the secondary transfer, and a recovery member for recovering the charged residual toner at a recovery position by voltage application. The intermediate transfer member exhibits a charging characteristic such that it has a surface potential of at most 500 volts as an absolute value at the recovery position.Type: GrantFiled: July 3, 1996Date of Patent: May 12, 1998Assignee: Canon Kabushiki KaishaInventors: Atsushi Tanaka, Hiroyuki Kobayashi, Akihiko Nakazawa, Tsunenori Ashibe, Takashi Kusaba
-
Patent number: 5744276Abstract: An electrophotographic toner composition suitable for heat-fixation and showing good storage characteristics is constituted by polymer components, a colorant and a metal-containing organic compound. The toner composition shows a melt index (at 125.degree. C., 10 kg-load) of 5-25 g/10 min., and the polymer components are characterized by (a) containing substantially no THF (tetrahydrofuran)-insoluble content, (b) including a THF-soluble content thereof providing a GPC (gel permeation chromatography) chromatogram showing i) a main peak in a molecular weight region of 2.times.10.sup.3 -3.times.10.sup.4, and a sub-peak or shoulder in a molecular weight region of at least 10.sup.5, and ii) an areal percentage of 3-10% in a molecular weight region of at least 10.sup.6, and (c) including a polymer component (H) in a molecular weight region of at least 10.sup.5 obtained by polymerization using a polyfunctional polymerization initiator and a monofunctional polymerization initiator.Type: GrantFiled: March 30, 1994Date of Patent: April 28, 1998Assignee: Canon Kabushiki KaishaInventors: Manabu Ohno, Hiroyuki Suematsu, Akihiko Nakazawa, Nobuyuki Okubo, Shunji Suzuki
-
Patent number: 5745831Abstract: An image forming apparatus has a first image supporting member and an intermediate transfer member having an outermost layer containing particles of conductive material. The ratio of (the maximum diameter/the minimum diameter) of the particle is 4 or more, and the maximum diameter is 1 to 80 .mu.m. The above image forming apparatus has excellent durability and good image forming properties, and produces images without toner-filming.Type: GrantFiled: December 1, 1995Date of Patent: April 28, 1998Assignee: Canon Kabushiki KaishaInventors: Akihiko Nakazawa, Hiroyuki Kobayashi, Atsushi Tanaka, Tsunenori Ashibe, Takashi Kusaba
-
Patent number: 5715510Abstract: An image forming apparatus having a first image supporting member and an intermediate transfer member for transfer of an image from the first image supporting member and means for transferring the transferred image on the intermediate transfer member to a second image supporting member; characterized in that the contact angle between a surface of the intermediate transfer member and water is 60.degree. or above, and the sliding resistance of the surface is 200 g or below. The above image forming apparatus has excellent durability and good image forming properties under overall environmental conditions, and produces images without toner-filming.Type: GrantFiled: November 21, 1995Date of Patent: February 3, 1998Assignee: Canon Kabushiki KaishaInventors: Takashi Kusaba, Hiroyuki Kobayashi, Akihiko Nakazawa, Atsushi Tanaka, Tsunenori Ashibe
-
Patent number: 5669052Abstract: An image forming apparatus includes a first image-forming member such as an electrophotographic photosensitive member, and an intermediate transfer member for receiving an image formed on the first image-bearing member and transferring the image onto a second image-bearing member such as plain paper. The intermediate transfer member has a surface layer comprising a binder and a powder dispersed therein. The binder is adjusted to have a tensile strength of at least 300 kg-f/cm.sup.2, an elongation of at least 150%, and a tensile stress of at most 250 kg-f/cm.sup.2 at an elongation of 100%. The powder may be a lubricating powder or an electroconductive powder.Type: GrantFiled: June 5, 1996Date of Patent: September 16, 1997Assignee: Canon Kabushiki KaishaInventors: Takashi Kusaba, Hiroyuki Kobayashi, Akihiko Nakazawa, Atsushi Tanaka, Tsunenori Ashibe
-
Patent number: 5620824Abstract: A toner for developing an electrostatic image has colored resin particles-(A) containing a coloring agent or a magnetic powder, and a powdery additive. The powdery additive has organic resin particles-(B) having peaks respectively in a region of particles diameters of 20 m.mu. to 200 m.mu. and a region of particle diameters of 300 m.mu. to 800 m.mu. in their particle size distribution, and the larger-diameters particles included in the region of particle diameters of 300 m.mu. to 800 m.mu. being contained in an amount of from 2% by weight to 20% by weight.Type: GrantFiled: July 7, 1994Date of Patent: April 15, 1997Assignee: Canon Kabushiki KaishaInventors: Kenji Okado, Akihiko Nakazawa, Ryoichi Fujita, Makoto Kanbayashi
-
Patent number: 5489498Abstract: The present invention relates a toner for developing electrostatic images, comprising: a resin composition, which contains a binder resin and low molecular weight wax, and a coloring agent, wherein the binder resin does not substantially contain insoluble tetrahydrofuran (THF) component, its chromatograph measured with soluble tetrahydrofuran (THF) component has a main peak in a region of a molecular weight of 2,000 to 30,000 and a subpeak or a shoulder in a high molecular weight region of a molecular weight of 100,000 or more, a ratio of weight average molecular weight (Mw)/number average molecular weight (Mn) thereof is 30 or more, the high molecular weight region has a crosslinking monomer unit as a component monomer unit and the binder resin contains high molecular weight polymer having a Mw of 1,200,000 or more polymerized by using both polyfunctional initiator and a mono-functional initiator. Moreover, the present invention relates to a method of manufacturing a resin composition for producing a toner.Type: GrantFiled: January 18, 1994Date of Patent: February 6, 1996Assignee: Canon Kabushiki KaishaInventors: Manabu Ohno, Akihiko Nakazawa, Nobuyuki Okubo, Shunji Suzuki, Hiroyuki Suematsu, Masayoshi Kato
-
Patent number: 5364720Abstract: A magnetic developer for developing electrostatic images is constituted by magnetic toner particles, each containing a binder resin having a melt viscosity of at most 5.0.times.10.sup.6 poise at 150.degree. C. and a magnetic material. The magnetic material is blended with a proportion (C) [wt. %] of inorganic fine particles based on the magnetic material to carry 0.2-5 wt. % of the inorganic fine particles secured to the magnetic material surface. The magnetic material has a specific surface area (A) [m.sup.2 /g] before securing of the inorganic fine particles and is provided with an increase in surface area (B) [m.sup.2 /g] by the securing of the inorganic fine particles; wherein the parameters A, B and C satisfy the following formulae (1) and (2):0.1.ltoreq.B/A.ltoreq.0.8 (1)B<30.times.C (2).Type: GrantFiled: October 14, 1993Date of Patent: November 15, 1994Assignee: Canon Kabushiki KaishaInventors: Akihiko Nakazawa, Masayoshi Kato, Manabu Ohno, Nobuyuki Okubo, Shunji Suzuki