Patents by Inventor Hiromi Demizu
Hiromi Demizu 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: 5155533Abstract: A device for controlling the application of a bias for development in electrophotographic image forming equipment which forms a latent image on a photoconductive element and develops it by a magnetic brush formed by a dry two-component developer on a developing sleeve to which the bias is applied. A detector is located between the optics and the developing unit for detecting the passage of opposite ends of a charged area of the photoconductive element one by one. The bias is turned on and then turned off, each later than the detection of a particular edge of the charged area by a period of time in which the edge travels from a sensing position to a developing position. The bias applied to the developing sleeve is turned on at the time when the leading edge of the actually charged area of the photoconductive element arrives at the developing position, and it is turned off at the time when the trailing edge of such an area passes the developing position.Type: GrantFiled: August 2, 1990Date of Patent: October 13, 1992Assignee: Ricoh Company, Ltd.Inventors: Junji Kurokawa, Tsukasa Adachi, Hiromi Demizu
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Patent number: 4930438Abstract: A developing device employing a non-magnetic one-component toner is provided and it includes a developing sleeve, which is driven to rotate in a predetermined direction past a developing region where toner carried on the sleeve is supplied to develop an electrostatic latent image formed on an image bearing member, a tank for storing therein a quantity of non-magnetic one-component toner and a flexible supply roller generally disposed between the tank and the developing sleeve for supplying the toner from the tank to the developing sleeve. The flexible supply roller rotates so as to be in sliding contact with the developing sleeve. With the provision of such a supply roller, even non-magnetic one-component toner can be suitably supplied to the developing sleeve to form thereon a thin film of charged toner for use in developing an electrostatic latent image.Type: GrantFiled: October 21, 1987Date of Patent: June 5, 1990Inventors: Hiromi Demizu, Makoto Obu, Hidetoshi Yano, Ryubun Seimiya, Noriyoshi Tarumi
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Patent number: 4760422Abstract: A device for developing an electrostatic latent image includes a developing sleeve and a sponge roller which is in scrubbing contact with the sleeve. Thus, even if non-magnetic, single component toner is used, it is electrically charged due to the scrubbing action and thus electrically attracted to the developing sleeve. A doctor blade is pressed against the developing sleeve and thus the toner is formed into a thin film having sufficient charge and a predetermined thickness. As the developing sleeve further rotates, thus formed thin film is brought to a developing region where the latent image is developed by the thin film of toner. Preferably, the blade is arranged in a particular orientation with respect to the sleeve. The blade may be movably provided so as to be pressed against the sleeve by an appropriate biasing element. The sleeve and the sponge roller may be driven to rotate same or opposite in direction, as desired. The sleeve may be formed to be elastically deformable.Type: GrantFiled: January 14, 1986Date of Patent: July 26, 1988Assignee: Ricoh Company, Ltd.Inventors: Ryubun Seimiya, Noriyoshi Tarumi, Hiromi Demizu, Makoto Obu, Hidetoshi Yano
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Patent number: 4696255Abstract: In a developing apparatus for a copying machine in which a latent image on a latent image carrying member is developed by supplying a thin layer of a developer to the latent image carrying member, an electrically insulating layer having a number of electrically conduction spots dispersed therein is provided on a developer carrier member for supplying a developer from a developer storage to a latent image carrying member.Type: GrantFiled: August 1, 1985Date of Patent: September 29, 1987Assignee: Ricoh Company, Ltd.Inventors: Hidetoshi Yano, Ryubun Seimiya, Noriyoshi Tarumi, Hiromi Demizu, Makoto Obu
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Patent number: 4521502Abstract: A color recording method wherein equal amounts of photoconductive toner particles of three primary colors are uniformly mixed and applied as a layer on a doner member. Optical color images are projected onto this layer, thereby selectively decreasing the resistivities of the toner particles in patterns corresponding to the optical color images. Simultaneously or immediately thereafter there is applied a voltage thereacross, thereby selectively injecting charge into the photoconductive toner particles with decreased electric resistivities to form a charge distribution in the mixed toner layer corresponding to the projected optical color images. Using the charge distribution formed in the mixed toner layer, color recording is then performed by transferring the toner particles to a recording sheet in accordance with the charge distribution.Type: GrantFiled: December 16, 1982Date of Patent: June 4, 1985Assignee: Ricoh Company, Ltd.Inventors: Katsuo Sakai, Hiromi Demizu
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Patent number: 4119060Abstract: A development apparatus for use with dry type copying apparatus having: a development roller, which is rotated in close proximity to a latent electrostatic image bearing recording material; a hopper for supplying an insulating toner onto the development roller; and a single developer regulating member in the form of a blade having an acute angle tip disposed at the edge of or right behind the outlet of the hopper in such manner that the top surface of the member forms an acute angle with the downstream side in the direction of development roller rotation of a tangent to the development roller at a point right under the tip of the development regulating member.Type: GrantFiled: July 13, 1977Date of Patent: October 10, 1978Assignee: Ricoh Co., Ltd.Inventors: Nobuo Mochizuki, Hiromi Demizu, Hajime Oyama, Teruyuki Ohnuma
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Patent number: 4100884Abstract: An apparatus for developing an electrostatic image on a photosensitive member or on a record member using one-component developer is provided. The developer comprises a magnetic toner or non-magnetic toner having a volumetric resistivity of not less than 10.sup.6 .OMEGA.cm. The apparatus comprises a developing roller at least the surface portion of which is formed of elastic rubber, means for supplying toner to the surface of the developing roller, and means for charging the toner on the developing roller to a given polarity. The developing roller is driven for rotation at a peripheral speed which is equal to or greater than the speed of movement of the image carrying member. Additionally, the apparatus includes levelling means for levelling the toner on the developing roller, charge neutralizing means for eliminating the electric charge from the toner after the developing step, and scraper means for stirring the toner after the developing step.Type: GrantFiled: February 15, 1977Date of Patent: July 18, 1978Assignee: Ricoh Company, Ltd.Inventors: Nobuo Mochizuki, Hiromi Demizu