Patents by Inventor Tomoharu Nishikawa
Tomoharu Nishikawa 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: 8213844Abstract: A developing device for an image forming apparatus of a non-magnetic one-component type. The developing device has a developing roller having a body and a shaft. Bearings for supporting the shaft have a groove made in a contact surface that is in contact with the shaft, and grease is pooled in the groove. The contact surface of the shaft has a surface roughness from 0.2 to 0.5, and the grease has consistency from 265 to 385 ( 1/10 mm·20° C.).Type: GrantFiled: August 14, 2009Date of Patent: July 3, 2012Assignee: Konica Minolta Business Technologies, Inc.Inventors: Tomoharu Nishikawa, Toshiyuki Sakai
-
Patent number: 8086151Abstract: A mono-component developing apparatus including a developing roller which transports toner supported on an outer circumferential face of a center portion toward a developing area by rotating while frictionally sliding on a sealing member on each of two end portions. The developing roller includes surface processing areas having a spiral shape, placed on each of outer circumferential faces of the two end portions. An angle, made by a spiral direction of each surface processing area and the rotation direction, is an acute angle. The developing roller inhibits toner leakage, with the driving torque of the developing roller being only slightly increased.Type: GrantFiled: May 5, 2008Date of Patent: December 27, 2011Assignee: Konica Minolta Business Technologies, Inc.Inventors: Tomoharu Nishikawa, Toshihide Taniguchi, Toshiyuki Sakai, Norikazu Okabe, Hiromasa Ueno
-
Publication number: 20100054822Abstract: A developing device for an image forming apparatus of a non-magnetic one-component type. The developing device has a developing roller having a body and a shaft. Bearings for supporting the shaft have a groove made in a contact surface that is in contact with the shaft, and grease is pooled in the groove. The contact surface of the shaft has a surface roughness from 0.2 to 0.5, and the grease has consistency from 265 to 385 ( 1/10 mm·20° C.).Type: ApplicationFiled: August 14, 2009Publication date: March 4, 2010Applicant: Konica Minolta Business Technologies, Inc.Inventors: Tomoharu NISHIKAWA, Toshiyuki Sakai
-
Publication number: 20080310889Abstract: To provide a developing roller which makes it possible to sufficiently prevent toner leakage, with the driving torque of the developing roller being scarcely increased, and a mono-component developing apparatus having such a developing roller. A developing roller for a mono-component developing apparatus, which transports toner supported on an outer circumferential face of a center portion 12 toward a developing area by rotating while frictionally sliding on a sealing member on each of two end portions 11a, 11b, comprising: surface processing areas 13 having a spiral shape, placed on each of outer circumferential faces of the two end portions, wherein an angle ?, made by a spiral direction y of each surface processing area and the rotation direction x, is allowed to have an acute angle, and a mono-component developing apparatus having such a developing roller.Type: ApplicationFiled: May 5, 2008Publication date: December 18, 2008Applicant: KONICA MINOLTA BUSINESS TECHNOLOGIES, INC.Inventors: Tomoharu NISHIKAWA, Toshihide Taniguchi, Toshiyuki Sakai, Norikazu Okabe, Hiromasa Ueno
-
Publication number: 20020098437Abstract: The present invention relates to a binder-type carrier comprising a copolymer obtained by using an ethylenic unsaturated nitrile as its constituent monomer, an amino-modified silicone oil, and magnetic particles.Type: ApplicationFiled: October 24, 2001Publication date: July 25, 2002Inventors: Makoto Kobayahsi, Tomoharu Nishikawa, Kochi Takenaka, Osamu Maeda, Hideaki Yasunaga, Yuji Shintani
-
Patent number: 6306552Abstract: A carrier having a BET specific surface area of 0.50 to 2.00 m2 and a dynamic current value of 15 to 170 nA and a two-component developer comprising such a carrier and toner.Type: GrantFiled: July 24, 2000Date of Patent: October 23, 2001Assignee: Minolta Co., Ltd.Inventors: Hideaki Yasunaga, Makoto Kobayashi, Koichi Takenaka, Osamu Maeda, Tomoharu Nishikawa
-
Patent number: 6165664Abstract: A two-component developing agent which is made from at least a carrier and a toner, characterized in that bulk specific density (AD.sub.1) of the carrier is set at 1.07 to 1.43 g/cc, bulk specific density (AD.sub.2) of the developing agent is set at 0.83 to 1.16 g/cc and AD.sub.2 /AD.sub.1 is set at 0.69 to 0.91. The present invention includes an image-forming method and an image-forming system, in which the above two-component developing agent is used.Type: GrantFiled: June 1, 1999Date of Patent: December 26, 2000Assignee: Minolta Co., Ltd.Inventors: Makoto Kobayashi, Tomoharu Nishikawa, Hideaki Yasunaga, Koichi Takenaka
-
Patent number: 6130019Abstract: The present invention relates to a binder carrier comprising at least magnetic particles and a binder resin. The binder resin contains a thermoplastic silicone-modified acrylic resin which is a copolymer of a polydiorgano-siloxane macromer having an acrylic functional group and a radical-polymerizable organic monomer.The binder carrier of the present invention a long-life binder carrier which eliminates the possibility of carrier deterioration due to toner components, such as a charge-controlling agent and an after-treatment agent, and which is less liable to deteriorate in its chargeability.Type: GrantFiled: December 1, 1998Date of Patent: October 10, 2000Assignee: Minolta Co., Ltd.Inventors: Tomoharu Nishikawa, Makoto Kobayashi, Koichi Takenaka, Hideaki Yasunaga, Hiroyuki Fukuda, Haruhiko Furukawa, Hiroshi Ueki, Yoshitsugu Morita
-
Patent number: 6099999Abstract: The present invention relates to a binder carrier, comprising at least magnetic particles and a binder resin, characterized in that the binder resin comprises a thermoplastic silicone-modified acrylic resin and an amino-group-containing resin. The binder carrier is capable of preventing carrier degradation caused by toner ingredients such as a charge-control agent and a post-processing agent for the toner. The binder carrier of the present invention has a long life with less susceptibility to degradation in charging performance, and makes it possible to quickly charge the toner sufficiently.Type: GrantFiled: April 6, 1999Date of Patent: August 8, 2000Assignee: Minolta Co., Ltd.Inventors: Koichi Takenaka, Makoto Kobayashi, Tomoharu Nishikawa, Hideaki Yasunaga, Hiroyuki Fukuda
-
Patent number: 6007956Abstract: The present invention relates a carrier comprising: a core particle comprising a binder resin and a first magnetic powder dispersed therein; and a second magnetic powder adhered onto the surface of the core particle, said second magnetic powder having a relative surface area larger than that of the first magnetic powder.Type: GrantFiled: January 23, 1996Date of Patent: December 28, 1999Assignee: Minolta Co., Ltd.Inventors: Hideaki Yasunaga, Tomoharu Nishikawa, Koichi Takenaka, Hiroshi Shibano
-
Patent number: 6001526Abstract: The present invention provides a binder carrier containing at least a magnetic particle and a binder resin, in which the binder resin comprises at least a copolymer containing an ethylenic unsaturated nitrile and preferably an optional silicone-modified acrylic resin.Type: GrantFiled: March 23, 1999Date of Patent: December 14, 1999Assignee: Minolta Co., Ltd.Inventors: Tomoharu Nishikawa, Makoto Kobayashi, Koichi Takenaka, Hideaki Yasunaga, Hiroyuki Fukuda
-
Patent number: 5962175Abstract: A binder-type carrier which does not cause image defects or uneven density and has excellent production characteristics, and a binder-type carrier manufactured by said method. The binder-type carrier has a magnetic powder content of 75-90 wt % and is produced by pulverizing via a mechanical pulverizer a material which has been kneaded within a predetermined temperature range using an extrusion kneader provided with two or more kneading units.Type: GrantFiled: February 23, 1998Date of Patent: October 5, 1999Assignee: Minolta Co., Ltd.Inventors: Yoshiaki Tanaka, Hideaki Yasunaga, Tomoharu Nishikawa
-
Patent number: 5849452Abstract: A developing method for developing electrostatic latent images comprising:(a) forming a thin layer of a developer comprising a toner and a carrier on a developer transporting member having a magnet therein by contacting the developer with a developer regulating member, wherein said carrier has a volume-average particle size of 10 to 50 .mu.m and a residual magnetization of 10 emu/g or less, and wherein an amount of said thin layer of developer is in the range of 0.7 to 10.0 mg/cm.sup.2 ;(b) transporting the thin layer to a developing region in which the developer transporting member confronts an image bearing member; and(c) supplying the toner contained in the developer from the developer transporting member to the image bearing member with applying an oscillated electric field on the developing region.Type: GrantFiled: March 13, 1997Date of Patent: December 15, 1998Assignee: Minolta Co., Ltd.Inventors: Koichi Takenaka, Makoto Kobayashi, Tomoharu Nishikawa, Hideaki Yasunaga
-
Patent number: 5834152Abstract: Carrier particles for electrostatic latent image development comprising first particles comprising a binder resin and a magnetic powder dispersed therein and second particles comprising a binder resin and a magnetic powder dispersed therein, said second particles having an average particle size smaller than said first particles, said magnetic powder contained in the first particles has a residual magnetization smaller than that of said magnetic powder contained in the second particles.Type: GrantFiled: March 14, 1996Date of Patent: November 10, 1998Assignee: Minolta,Co., Ltd.Inventors: Hideaki Yasunaga, Tomoharu Nishikawa, Koichi Takenaka, Hiroshi Shibano
-
Patent number: 5736287Abstract: A development method comprising the steps of forming a layer of a developer comprising a toner and a magnetic carrier on a developer transporting member containing a magnet therein by means of a developer regulating member, transporting the developer layer on the developer transporting member to a development region where the developer transporting member opposes an image bearing member, and applying an oscillating electric field to the development region for supplying the toner from the developer layer to the image bearing member, thereby developing an image. The magnetic carrier comprises a magnetic powder dispersed in a binder resin having an acid value of 0 to 20 KOHmg/g and has 5 to 30 wt % of magnetic powder present on the surface thereof.Type: GrantFiled: March 14, 1997Date of Patent: April 7, 1998Assignee: Minolta Co., Ltd.Inventors: Makoto Kobayashi, Hideaki Yasunaga, Tomoharu Nishikawa, Koichi Takenaka
-
Patent number: 5689781Abstract: A carrier for electrostatic latent image developing for use in methods of developing an electrostatic latent image formed on the surface of a latent image-bearing member by transporting a developer comprising a toner and a carrier via the rotation of a developing sleeve having a built in stationary magnet roller, the carrier for electrostatic latent image developing including magnetic powder dispersed in a binder resin and having a saturation magnetization of about 50 to about 80 emu/g, residual magnetization of about 3 to about 10 emu/g, and coercive force of about 20 to about 50 oersted.Type: GrantFiled: August 31, 1995Date of Patent: November 18, 1997Assignee: Minolta Co., Ltd.Inventors: Hiroshi Shibano, Tomoharu Nishikawa, Koichi Takenaka, Hideaki Yasunaga
-
Patent number: 5472817Abstract: The present invention provide a carrier for development of electrostatic latent images, comprising magnetic powder dispersed in binder resin, the carrier having a mean particle size in a range of 30 to 80 .mu.m and satisfying the following relational expression:(x).sup.2 /.phi..sup.2 .gtoreq.9.0wherein x represents mean particle size of the carrier and .phi..sup.2 represents variance of particle size distribution.The carrier of the present invention is superior in chargeability and fluidity and free from occurrence of carrier adhesion even when used in combination with small particle size toner and which can form excellent copy images.Type: GrantFiled: July 28, 1994Date of Patent: December 5, 1995Assignee: Minolta Co., Ltd.Inventors: Hiroshi Shibano, Tomoharu Nishikawa, Koichi Takenaka