Patents by Inventor Teruaki Higashiguchi
Teruaki Higashiguchi 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: 5446615Abstract: An electrifying method which uses a electrifying a material wherein the contact-type electrifying member comprises a flexible and electrically conducting endless sheet and a brush which supports said endless sheet and imparts a pressing force thereto at a position where said endless sheet is in contact with the material to be electrified, said endless sheet which is impressed with an electrification voltage is driven or is moved at a speed which is substantially in synchronism with the material to be electrified, and the brush and the endless sheet are maintained at dissimilar speeds.Type: GrantFiled: March 26, 1993Date of Patent: August 29, 1995Assignee: Mita Industrial Co., Ltd.Inventors: Shoji Matsumoto, Masanori Matsuda, Eiji Goto, Akinori Nishida, Teruaki Higashiguchi, Isao Iwagawa
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Patent number: 5060023Abstract: The present invention relates to a developing process for forming a high-quality image in the electrophotography. In this developing process, a two-component type developer is used and the moving direction of a developing sleeve is the same as the moving direction of a photosensitive material drum at the position of the sliding contact of the photosensitive material drum with a magnetic brush of the developer. In carrying out this forward direction sliding contact developing process, by setting the angle .theta. of a fixed main developing pole to the direction reverse to the moving direction of the sleeve from the line connecting the centers of the drum and sleeve and the drum/sleeve diameter ratio within certain specific ranges, the reproducibility of fine lines and the image density can be simultaneously improved very effectively in a well-balanced state, and a toner image having a high quality can be formed.Type: GrantFiled: June 27, 1990Date of Patent: October 22, 1991Assignee: Mita Industrial Co., Ltd.Inventors: Teruaki Higashiguchi, Takeshi Hori
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Patent number: 5049471Abstract: An optimum image can be obtained by carrying out the development while using a two-component type developer comprising an electroscopic toner and a magnetic carrier and maintaining the peripheral speed ratio of the magnet sleeve to the photosensitive material drum within a certain range according to the average particle size and saturation magnetization of the magnetic carrier.Type: GrantFiled: November 28, 1989Date of Patent: September 17, 1991Assignee: Mita Industrial Co., Ltd.Inventors: Teruaki Higashiguchi, Junko Mizuno
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Patent number: 5049470Abstract: An optimum image can be obtained by carrying out the development while using a two-component type developer comprising an electroscopic toner and a magnetic carrier and having a specific toner concentration and maintaining the peripheral speed ratio of the magnet sleeve to the photosensitive material drum within a certain range according to the average particle size, saturation magnetization and electric resistance value of the magnetic carrier.Type: GrantFiled: November 28, 1989Date of Patent: September 17, 1991Assignee: Mita Industrial Co., Ltd.Inventors: Teruaki Higashiguchi, Junko Mizuno
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Patent number: 4963454Abstract: In an electrophotographic developing method using a magnetic brush consisting of a mixture of magnetic carrier and an electroscopic toner, development is carried out at a toner concentration (Ct. %) in the mixture, which satisfies the requirement represented by the following formula: ##EQU1## wherein Sc stands for the specific surface area (cm.sup.2 /g) of the carrier, St stands for the specific surface area (cm.sup.2 /g) of the toner, and k is a number of from 0.90 to 1.14.A toner image having a high quality can be obtained according to this method.Type: GrantFiled: October 3, 1986Date of Patent: October 16, 1990Assignee: Mita Industrial Co., Ltd.Inventors: Koji Yano, Nobuhiro Miyakawa, Teruaki Higashiguchi, Kazuo Yamamoto, Yoshinobu Kawakami
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Patent number: 4949127Abstract: An optimum image can be obtained by carrying out the development while using a two-component type developer comprising an electroscopic toner and a magnetic carrier and maintaining the peripheral speed ratio of the magnet sleeve to the photosensitive material drum within a certain range according to the average particle size and saturation magnetization of the magnetic carrier and the dynamic friction coefficient of the magnetic brush.Type: GrantFiled: November 28, 1989Date of Patent: August 14, 1990Assignee: Mita Industrial Co., Ltd.Inventors: Tomiyasu Matsuda, Teruaki Higashiguchi
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Patent number: 4614698Abstract: A two-component electrophotographic developer for use in developing a latent electrostatic image of a low potential. The developer is composed of a mixture of a magnetic carrier of spherical sintered ferrite particles having raised and depressed portions attributed to the primary particles on their surface, a median size of from 30 to 50 micrometers, an apparent density of less than 2.6 g/cc and an electric resistance, measured in the form of a magnetic brush, of from 6.times.10.sup.4 to 2.5.times.10.sup.6 ohms and chargeable toner particles having a volume inherent resistivity of at least 1.times.10.sup.13 ohms-cm and a specific inductive capacity of from 4 to 6. In a preferred embodiment, the chargeable toner particles have a median size of from 10 to 14 micrometers and are substantially free from particles having a particle diameter of not more than 5 micrometers. The developer can give an image of a high density, a high resolution and excellent gradation without brush marks.Type: GrantFiled: November 27, 1985Date of Patent: September 30, 1986Assignee: Mita Industrial Co., Ltd.Inventors: Nobuhiro Miyakawa, Koji Yano, Kazuo Yamamoto, Teruaki Higashiguchi, Yoshinobu Kawakami
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Patent number: 4607936Abstract: Disclosed is an electrophotographic apparatus comprising a photosensitive drum comprising an amorphous silicon type photoconductor layer formed on an electroconductive substrate, a main charging mechanism for charging the surface of the drum with charges having a predetermined polarity, an imagewise exposure mechanism for forming an electrostatic image corresponding to an image of an original on the surface of the drum, a toner development mechanism for forming a toner image corresponding to the electrostatic image, a toner image transfer mechanism for transferring the toner image formed on the surface of the photosensitive drum to a predetermined paper sheet, a toner cleaning mechanism for removing the residual toner adhering to the surface of the photosensitive drum and a fixing mechanism for fixing the transferred toner image to said paper sheet, wherein a heating mechanism is arranged to heat the surface of the photosensitive drum at a temperature of 30.degree. to 40.degree. C.Type: GrantFiled: September 28, 1984Date of Patent: August 26, 1986Assignee: Mita Industrial Co., Ltd.Inventors: Nobuhiro Miyakawa, Teruaki Higashiguchi, Koji Yano, Kazuo Yamamoto, Yoshinobu Kawakami
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Patent number: 4592643Abstract: In a copying machine comprising a photosensitive drum having an amorphous silicon type photoconductive layer, if an image of an original is focussed on the photoconductive layer with a light having a wavelength shorter than 600 nm, the light fatigue of the amorphous silicon photoconductive layer is prevented, and the image memory phenomenon owing to the light fatigue is effectively obviated.Type: GrantFiled: March 28, 1985Date of Patent: June 3, 1986Assignee: Mita Industrial Co., Ltd.Inventors: Teruaki Higashiguchi, Nobuhiro Miyakawa, Koji Yano, Kazuo Yamamoto, Yoshinobu Kawakami
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Patent number: 4576888Abstract: A toner for electrophotography, comprising an azoic pigment having a silica core as a coloring component, said azoic pigment comprising a core of a fine powder of silica and a coating of a mono- or polyazoic dye chemically bound to the surface of the silica core through an aminosilane coupling agent.Type: GrantFiled: February 24, 1984Date of Patent: March 18, 1986Assignee: Mita Industrial Company, LimitedInventors: Nobuhiro Miyakawa, Kouji Maekawa, Teruaki Higashiguchi, Kaname Nakatani
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Patent number: 4566908Abstract: An azoic pigment having a silica core comprising a core of a fine powder of silica having a particle diameter of not more than 10 microns and a coating of a mono- or polyazoic dye chemically bound to the surface of the silica core through an aminosilane coupling agent.Type: GrantFiled: February 24, 1984Date of Patent: January 28, 1986Assignee: Mita Industrial Company, LimitedInventors: Kaname Nakatani, Nobuhiro Miyakawa, Teruaki Higashiguchi, Syoji Nakagama
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Patent number: 4535044Abstract: Disclosed is a photosensitive material for electrophotography containing a pentakisazo pigment of the following formula: ##STR1## wherein the rings A.sub.1 and A.sub.2 may have halogen atoms, alkyl groups or alkoxy groups as substituents at the ortho-positions to the azo groups, the ring B may have a halogen atom, an alkyl group or an alkoxy group as a substituent or may contain the ring Z.sub.1, Z.sub.1 which is an aromatic or hetero ring fused to the benzene ring B, and Y stands for a group of the following formula: ##STR2## in which Z.sub.2 stands for an aromatic ring or a hetero ring, Ar.sub.1 stands for an aromatic ring or a hetero ring, Ar.sub.2 and Ar.sub.3 stand for an aromatic ring, R.sub.0 stands for a hydrogen atom, a lower alkyl group or a phenyl group, R.sub.1 stands for a lower alkyl group, a carboxyl group or an ester thereof, and R.sub.2 and R.sub.3 stand for a hydrogen atom, a lower alkyl group, a phenyl group or a substituted derivative thereof.Type: GrantFiled: May 9, 1983Date of Patent: August 13, 1985Assignee: Mita Industrial Co., Ltd.Inventors: Teruaki Higashiguchi, Nobuhiro Miyakawa
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Patent number: 4524118Abstract: Electrophotographic photosensitive material comprising an electroconductive substrate and a layer of a photoconductive composition composed of a dispersion of a charge generating pigment in a charge transporting medium, which is formed on the electroconductive substrate, wherein said photoconductive composition contains an N,N-di-substituted-carbamic acid salt in an amount of 20 to 200% by weight based on the charge generating pigment. This electrophotographic electrophotosensitive material has excellent ozone resistance and shows a high initial charge retention ratio and sensitivity retention ratio when the cycle of charging and light exposure is repeated many times.Type: GrantFiled: June 17, 1983Date of Patent: June 18, 1985Assignee: Mita Industrial Co., Ltd.Inventors: Kaname Nakatani, Nobuhiro Miyakawa, Teruaki Higashiguchi, Tomomi Edo
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Patent number: 4480019Abstract: Disclosed is a photosensitive material for electrophotography, which comprises a photosensitive layer containing a disazo pigment represented by the following formula: ##STR1## wherein R.sub.1 stands for a lower alkyl group or a lower alkoxy group, n is a number of zero, 1 or 2, R.sub.2 stands for a lower alkyl group, a lower alkoxy group, a di-lower-alkylamino group, a nitro group or a halogen atom, m is a number of zero, 1 or 2, Z stands for a benzene ring or a naphthalene ring, and Y stands for a group represented by the following formula: ##STR2## in which B stands for a benzene, naphthalene, indole, carbazole or benzofuran ring or a substitution product thereof, which is fused to the benzene ring, Ar.sub.1 and Ar.sub.2 stand for a benzene ring, a naphthalene ring, a dibenzofuran ring or a substitution product thereof, R.sub.3 stands for a lower alkyl group, a carboxyl group or a carboxyl ester group, and R.sub.Type: GrantFiled: April 12, 1983Date of Patent: October 30, 1984Assignee: Mita Industrial Co., Ltd.Inventors: Teruaki Higashiguchi, Kaname Nakatani, Nobuhiro Miyakawa
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Patent number: 4447513Abstract: Disclosed is a photosensitive material for electrophotography, which comprises a photosensitive layer containing a tetrakis-azo pigment represented by the following formula: ##STR1## wherein X.sub.1 stands for a lower alkyl group, a lower alkoxy group or a halogen atom, X.sub.2 and X.sub.3 stand for a lower alkyl group, a lower alkoxy group, a halogen atom or a hydrogen atom, and Y stands for a group represented by the following group: ##STR2## in which Z stands for an aromatic ring such as a benzene or naphthalene ring, a substitution product thereof, a hetero ring such as an indole, carbazole or benzofuran ring, or substitution product thereof, Ar.sub.1 stands for an aromatic ring such as a benzene or naphthalene ring, a substitution product thereof, a hetero ring such as a dibenzofuran ring, or a substitution product thereof, Ar.sub.2 and Ar.sub.3 stand for an aromatic ring such as a benzene or naphthalene ring or a substitution product thereof, R.sub.Type: GrantFiled: January 25, 1983Date of Patent: May 8, 1984Assignee: Mita Industrial Co., Ltd.Inventors: Nobuhiro Miyakawa, Teruaki Higashiguchi, Yumiko Sano, Masatomi Funato