Patents by Inventor Seiji Oka
Seiji Oka 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).
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Patent number: 5805965Abstract: A developing device of the type developing a latent image formed on an image carrier with a two-ingredient type developer, i.e., a mixture of toner and magnetic carrier particles is disclosed. The device is operable without a sophisticated toner content control mechanism or a sophisticated developer agitating and conveying mechanism, and is capable of obviating various problems ascribable to the increase in the toner content of the developer at the opposite end portions of a developer carrier. For this purpose, the device restricts the movement of a developer present on the developer carrier in the direction substantially perpendicular to the direction in which the developer carrier conveys the developer.Type: GrantFiled: November 13, 1996Date of Patent: September 8, 1998Assignee: Ricoh Company, Ltd.Inventors: Kiyonori Tsuda, Seiji Oka, Hajime Oyama, Yasushi Akiba
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Patent number: 5771429Abstract: A developing device for an image forming apparatus and capable of automatically controlling the toner content of a developer is disclosed. Even when the toner content of the developer deposited on a developer carrier and being conveyed toward a developing position becomes irregular due to some cause, the developer is prevented from remaining at the developing position. This guarantees a desired developing position despite the automatic toner content control. In addition, the toner content of the developer is prevented from increasing at portions adjoining the opposite ends of the developer carrier.Type: GrantFiled: October 30, 1996Date of Patent: June 23, 1998Assignee: Ricoh Company, Ltd.Inventors: Hajime Oyama, Seiji Oka, Kiyonori Tsuda, Yasushi Akiba
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Patent number: 5771426Abstract: In a developing device for an image forming apparatus and of the type using a developer consisting of toner and magnetic carrier, a toner hopper has an opening for replenishing toner stored therein. The developer is regulated by a doctor blade to form a thin layer on a developing sleeve. The developer scraped off by the doctor blade is introduced into a developer storing chamber and caused to move toward the opening of the hopper due to its own internal pressure and gravity. The developer from the hopper is returned toward the doctor blade along the surface of the sleeve. The developer on the sleeve and regulated by the doctor blade is conveyed to a developing position where the sleeve faces an image carrier. The toner contained in the developer is a magnetic toner. When the toner concentration of the developer has reached an upper limit, a space or gap exists in the developer storing chamber.Type: GrantFiled: April 19, 1996Date of Patent: June 23, 1998Assignee: Ricoh Company, Ltd.Inventors: Seiji Oka, Kiyonori Tsuda, Hajime Oyama, Fumihiro Sasaki, Satoshi Mochizuki, Takahisa Kato
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Patent number: 5758241Abstract: A developing device for an image forming apparatus and of the type using a developer consisting of toner and magnetic particles is disclosed. While a developing sleeve conveys the developer deposited thereon, toner is automatically replenished to the developer from a toner hopper via an opening formed in the hopper due to the movement of the developer. At the same time, the toner introduced into the developer is charged by friction. A developer storing member includes a penthouse portion. A projection protrudes from the surface of the penthouse portion facing the developing sleeve toward the sleeve and extends in the direction perpendicular to the direction in which the sleeve conveys the developer. The developer forms on the sleeve a layer having stable toner content and stable toner charge without resorting to a sophisticated toner content control mechanism.Type: GrantFiled: December 18, 1996Date of Patent: May 26, 1998Assignee: Ricoh Company, Ltd.Inventors: Hajime Oyama, Seiji Oka, Kiyonori Tsuda, Yasushi Akiba
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Patent number: 5661223Abstract: A resin composition for a laminate comprises 100 parts by weight of a polyfunctional epoxy resin (I) obtained by (i)(1) glycidylizing a polycomposite formed from a blend of brominated bisphenol A and bisphenol A, or brominated bisphenol A and formaldehyde; or (2) a mixture of a polyfunctional epoxy resin and a bisphenol A-advanced epoxy resin reacted with brominated bisphenol A in a hydroxyl:epoxy equivalent ratio of from 0.05-0.5:1 and (ii) a bisphenol A-formaldehyde phenolic resin having a weight average molecular weight of from 1,000-10,000 in a hydroxyl:epoxy equivalent ratio with respect to epoxy resin (i) of from 0.7-1.2:1; and (II) from 1-60 parts by weight of a straight chain polymer (c) such as a poly(ether)sulfone, aromatic polyester, phenoxy resin, polyparabanic acid, polyetherimide or polyphenylene sulfide.Type: GrantFiled: June 7, 1995Date of Patent: August 26, 1997Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Seiji Oka, Mitsuhiro Nonogaki, Takumi Kikuchi, Takashi Takahama, Hiroyuki Nakajima, Michio Futakuchi
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Patent number: 5659860Abstract: In an image forming apparatus, a developing device has a developing sleeve accommodating a magnet roller therein, and a doctor for regulating the amount of developer to be conveyed to a developing position. When the developing sleeve is rotated, the part of the doctor shaved off by the doctor from the sleeve is moved in a developer storing section to a toner replenishing opening formed in a toner storing section. Then, this part of the developer is returned to the doctor along the surface of the sleeve via the toner replenishing opening. The developer consists of a first developer containing a first carrier and deposited in a layer on the surface of the sleeve, and a second developer containing a second carrier different from the first carrier and stored in the developer storing section in such a manner as to contact the first developer deposited on the sleeve. The first carrier has a higher charging ability than the second carrier.Type: GrantFiled: October 3, 1995Date of Patent: August 19, 1997Assignee: Ricoh Company, Ltd.Inventors: Fumihiro Sasaki, Satoshi Mochizuki, Hidefumi Gohhara, Megumi Sakakura, Seiji Oka, Hajime Oyama, Kiyonori Tsuda, Yasushi Akiba
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Patent number: 5555469Abstract: An image forming apparatus of the type collecting a toner remaining on the surface of an image carrier after image transfer and returning it to a developing unit to use it again. The apparatus separates the toner from paper dust and other impurities before returning the toner to the developing unit on the basis of differences in charge, weight and volume between the toner and the impurities. The toner is returned via an eletrostatic conveyor.Type: GrantFiled: October 17, 1994Date of Patent: September 10, 1996Assignee: Ricoh Company, Ltd.Inventors: Fumihiko Ishikawa, Seiji Oka, Tsukuru Kai
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Patent number: 5416568Abstract: A developing unit incorporated in an image forming apparatus and capable of transporting a developer or a toner deposited on a developing roller in a predetermined direction without rotating the developing roller, or developer carrier. The developing roller has an unrotatable base roller, a stationary body provided on the base roller and made of an insulating material, and a plurality of drive electrodes buried in the stationary body. The drive electrodes are divided into three electrode groups. Voltages whose polarities change at predetermined intervals are applied to the three electrode groups, causing the toner to be transported by the coaction of the charge of the toner and the charges of the drive electrodes. The drive electrodes are arranged at a pitch which is substantially one-third of the particle size of the toner, so that the toner may be deposited on the developing roller substantially without any clearance.Type: GrantFiled: June 17, 1993Date of Patent: May 16, 1995Assignee: Ricoh Company, Ltd.Inventors: Shigeru Yoshiki, Seiji Oka, Tomoji Ishikawa, Tsukuru Kai
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Patent number: 5255059Abstract: An image forming apparatus having a developing device which includes a developing roller. A developer or a toner is transported on and along the developing roller without the roller being rotated. The developing roller has a shaft and ultrasonic transport members provided on the shaft. The ultrasonic transport members are made up of a plurality of electrodes, a piezoelectric member surrounding the electrodes and made of, for example, piezoelectric ceramic, and an elastic member surrounding the piezoelectric member and made of, for example, copper alloy or similar alloy. A plurality of standing waves are caused to flow through the electrodes with the result that the piezoelectric member waves. The toner is transported on the waving surface of the elastic member.Type: GrantFiled: March 13, 1992Date of Patent: October 19, 1993Assignee: Ricoh Company, Ltd.Inventors: Tsukuru Kai, Seiji Oka, Hidetoshi Yano, Shigeru Yoshiki, Tsuyoshi Deki
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Patent number: 5235384Abstract: An image forming apparatus having various process units at least one of which is removable for replacement. The apparatus has a mode selecting a device accessible for selecting desired one of a plurality of image modes. A photoconductive element, developing unit, image transferring unit and other replaceable process units each is provided with a storage for storing image forming conditions which match an image mode selected on the mode selecting device. A copy process and other conditions are set up on the basis of the conditions stored in the storage. Another storage is loaded with data associated with the service life of a replaceable process unit.Type: GrantFiled: July 6, 1990Date of Patent: August 10, 1993Assignee: Ricoh Company, Ltd.Inventors: Seiji Oka, Tomoji Ishikawa, Tsukuru Kai, Hisashi Ishijima, Makoto Obu, Hidetoshi Yano
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Patent number: 5109254Abstract: A developing apparatus has a developer cartridge having a first developer storage room for storing an unused new developer, a second developer storage room for storing a used old developer, and shutter members for opening and closing openings of the first and second developer storage rooms; and a device for detachably attaching the developer cartridge to a section for exchanging the old developer for the new developer on a body side of the developing apparatus. The developer cartridge may be attached and detached from the developer exchanging section after deterioration of the developer in use is displayed, and the used developer is collected within the second developer storage room and the new developer is supplied into the developer cartridge after the collection of the used developer.Type: GrantFiled: August 22, 1990Date of Patent: April 28, 1992Assignee: Ricoh Company, Ltd.Inventors: Seiji Oka, Tsukuru Kai, Masaru Tanaka, Tomoji Ishikawa
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Patent number: 5091481Abstract: A resin composition for laminate, which comprises 100 parts by weight of a composition (B), from 0.5 to 10 parts by weight of dicyandiamide and from 1 to 100 parts by weight of a linear polymer, said composition (B) comprising (i) a composition (A) comprising from 20 to 80 parts by weight of a polyfunctional epoxy compound of the formula: ##STR1## wherein R is H or CH.sub.3 and n is an integer of from 0 to 5, and from 80 to 20 parts by weight of an epoxy compound having two epoxy groups in one molecule, and (ii) an aromatic diamino compound incorporated in the composition (A) in such an amount that its active hydrogen is from 0.3 to 0.8 equivalent per equivalent of terminal epoxy groups.Type: GrantFiled: July 13, 1989Date of Patent: February 25, 1992Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Hiroyuki Nakajima, Takashi Takahama, Fumiyuki Miyamoto, Seiji Oka, Toshio Isooka, Yoshihiro Maruyama, Yasushi Yamamoto
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Patent number: 5077584Abstract: A toner supply device incorporated in electrophotographic equipment which develops a latent image electrostatically formed on an image carrier by using toner. The device has a toner tank for supplying toner to a developing section which forms a part of the equipment, a toner sensor responsive to the amount of toner remaining in the toner tank, and a toner server adjoining the toner tank for feeding toner to the tank. The toner server has a plurality of toner cartridges thereinside and automatically replaces the toner cartridge a plurality of times.Type: GrantFiled: April 16, 1990Date of Patent: December 31, 1991Assignee: Ricoh Company, Ltd.Inventors: Masaru Tanaka, Seiji Oka
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Patent number: 4969557Abstract: A toner cartridge is provided for use in replenishing toner to a toner storing section of an imaging machine, such as a copying machine, which uses toner to produce a visible image. The toner cartridge includes a container having an opening, a folded over seal member having one end fixed to the container and another end fixed to a roller, and means for winding up the seal member which includes a roller provided with a shaft. When the shaft is rotated, the seal member is peeled off the container to unseal its opening. The toner drops from the container into the toner storing section. The seal member can be easily peeled off from the container, and toner is kept from being spilled and from soiling the operator.Type: GrantFiled: November 26, 1985Date of Patent: November 13, 1990Assignee: Ricoh Co., Ltd.Inventor: Seiji Oka
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Patent number: 4882389Abstract: A resin having a low dielectric constant obtained by heat-curing 100 parts by weight of a butadiene polymer containing in its polymer chain at least 50 mol% of a 1,2-butadiene unit having a double bond in its side chain and from 10 to 100 parts by weight of a vinyl compound having at least 3 vinyl groups in one molecule in the presence of an organic peroxide. Also disclosed is a resin having flame resistance obtained by heat-curing a blend of an organic peroxide with a composition comprising 100 parts by weight of a butadiene polymer containing in its polymer chain at least 50 mol% of a 1,2-butadiene unit having a double bond in its side chain, from 10 to 100 parts by weight of a vinyl compound having at least 3 vinyl groups in one molecule and at least one member selected from the compounds of the formulas I-IV: ##STR1## wherein X is H or CH.sub.3, Y is Br or Cl, A is --, --o--, --CO--, SO.sub.2, --CH.dbd.CH--, --C(CH.sub.3).sub.2 --or --(CH.sub.2 .sub.Type: GrantFiled: December 18, 1987Date of Patent: November 21, 1989Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Makoto Doi, Hiroyukio Nakajima, Fumiyuki Miyamoto, Seiji Oka, Mitsuhiro Nonogaki
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Patent number: 4799608Abstract: A toner cartridge mounted in a developing device for supplying toner includes a container which stores toner therein. One half of a doubled seal member is stuck to an open portion of the container, and the other half is fixed to a take-up roller which is journalled to the container. A cover is slidably mounted to the container to open and close the open portion of the latter. A rack which is provided on the inner surface of the cover is held in mesh with a gear which is integral with the take-up roller.Type: GrantFiled: September 16, 1987Date of Patent: January 24, 1989Assignee: Ricoh Company, Ltd.Inventor: Seiji Oka
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Patent number: 4800411Abstract: A magnetic brush development device has a development casing housing a development sleeve for carrying a magnetic brush thereon, the development sleeve confronting an electrostatic latent image carrier such as a photosensitive drum. When the development sleeve rotates, toner carried by the development sleeve acts as a pump for air inside the development casing housing, and the pumping action of the air causes developer to be scattered out of the housing. However, according to the invention, the development casing has spaces defined therein around the development sleeve and communicating with each other to equalize pressures therein for thereby preventing developer from being scattered out.Type: GrantFiled: April 10, 1987Date of Patent: January 24, 1989Assignee: Ricoh Company, Ltd.Inventors: Masaru Tanaka, Seiji Oka
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Patent number: 4650070Abstract: A toner cartridge for use in replenishing additional toner to a toner storing section of an imaging machine, such as an electrophotographic copier, which uses toner to produce a visible image is provided. The present toner cartridge includes a trough-shaped container having an opening, a cover which is large enough to encompass the opening and supported to be slidably movable with respect to the container between a closed position to close the opening and an open position to open the opening, and a seal member having one end fixed to the container and another end fixed to the cover. Thus, when the cover is moved from the closed position to the open position, the seal member is partly separated away from the container to make the opening half-open. Then, the seal member is pulled to completely open the opening to have the toner completely discharged from the container. Thereafter, the cover is returned to the closed position to close the opening.Type: GrantFiled: February 29, 1984Date of Patent: March 17, 1987Assignee: Ricoh Company, Ltd.Inventors: Seiji Oka, Yoshiharu Morita
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Patent number: 4603180Abstract: A thermosetting resin composition, consists essentially of:(a) 100 parts by weight of a mixture of liquid acid anhydride and an imide ring-containing epoxy compound obtained from reaction of an epoxy compound having in one molecule thereof at least two epoxy groups and either one or both of imide ring-containing dicarboxylic acid compounds represented by the following general formulae (I) and (II): ##STR1## (where: R.sub.1 is a divalent organic radical) ##STR2## (where: R.sub.2 is a divalent organic radical): (b) 5 to 200 parts by weight of a tri-functional vinyl monomer; and(c) 0.1 to 10 parts by weight of phenoxy resin.Type: GrantFiled: June 18, 1985Date of Patent: July 29, 1986Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Hiroyuki Nakajima, Fumiyuki Miyamoto, Masakazu Murayama, Seiji Oka, Eiki Jidai
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Patent number: 4591623Abstract: A thermosetting resin composition, which is characterized by mixing 5 to 300 parts by weight of tri-functional vinyl monomer and 0.1 to 10 parts by weight of phenoxy resin with respect to 100 parts by weight in total of an epoxy compound containing in its molecule at least two epoxy groups and a curing agent for said epoxy compound.Type: GrantFiled: June 12, 1985Date of Patent: May 27, 1986Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Hiroyuki Nakajima, Fumiyuki Miyamoto, Masakazu Murayama, Seiji Oka, Eiki Jidai