Having Applied Bias Patents (Class 399/285)
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Patent number: 6954604Abstract: The invention provides an electronic photographing apparatus using a two-component developer as a mixture of a toner and a carrier as well as a development unit including a developer roll having magnetic poles therein. The electronic photographing apparatus includes a development bias power source for applying to the developer roll a development bias voltage where an AC voltage is superimposed on a DC voltage. The electronic photographing apparatus develops a latent image on a photosensitive body by using toner to form an image, characterized in that the ratio of the volume of the carrier to a space sandwiched between the developer roll and the photosensitive body is set within a range from 32 percent to 46 percent and that that the resistivity of the carrier under a field strength of 2000 V/cm is set to 3×1010 ?cm or more.Type: GrantFiled: January 29, 2004Date of Patent: October 11, 2005Assignee: Ricoh Printing Systems, Ltd.Inventors: Hisao Okada, Masayoshi Nakayama
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Patent number: 6922541Abstract: Apparatus and methods in accordance with the present invention relate to fusing of images to imaging media. A method in accordance with one embodiment of the present invention includes defining an initial image area on the imaging media, and ascertaining one or more input parameters corresponding to the initial imaging area. The method further includes determining a heater-on period and/or a heater-on frequency as a function of the one or more input parameters, and operating the heater at the heater-on frequency and/or the heater-on period to fuse the initial imaging area.Type: GrantFiled: June 17, 2003Date of Patent: July 26, 2005Assignee: Hewlett-Packard Development Company, LP.Inventor: Quintin T. Phillips
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Patent number: 6917768Abstract: An image forming device includes a storage device that stores toner, an agitator that agitates the toner in the storage device, a detector that detects an amount of toner in the storage device, and a controller that prohibits an operation of the agitator when the detected amount of toner is equal to or more than a prescribed amount, and permits the operation of the agitator when the amount of toner is less than the prescribed amount. A controller circuit sets a voltage level based on the amount of toner and a biasing circuit impresses the voltage to a developing roller, a supply roller and a regulating blade.Type: GrantFiled: March 18, 2003Date of Patent: July 12, 2005Assignee: Murata Kikai Kabushiki KaishaInventor: Akinori Nishida
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Patent number: 6917780Abstract: An image forming apparatus of non-contact developing method using two-component developer material which is capable of obtaining a clear image free from fogging, ghost and toner contamination. The image forming apparatus has at least one developing unit which includes a developing roll and a magnetic roll, the developing unit develops an electrostatic latent image on a photosensitive body with a toner thin layer formed on the surface of a developing roll wherein a toner thin layer forming region on the developing roll is smaller than a magnetic brush forming region on the magnetic roll. A high resistivity region is adjacent each end of the toner thin layer forming region on the developing roll. A control device controls a developer material replenishment and controls the biasing to the developing roll and magnetic roll.Type: GrantFiled: June 13, 2002Date of Patent: July 12, 2005Assignee: Kyocera CorporationInventors: Yoshio Ozawa, Eiji Ochiai, Shoichi Sakata, Toshinori Nishimura, Masayoshi Yamada
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Patent number: 6901231Abstract: A developing device including a latent image supporter. Powder is adhered on the latent image supporter to develop a latent image on the latent image supporter and a transporting member is arranged opposite to the latent image supporter. A plurality of electrodes are formed in the transporting member for generating a traveling-wave electric field to move the powder, and n-phase voltages are applied to the electrodes of the transporting member to form an electric field in a first direction so that the powder moves towards the latent image supporter at an image portion of the latent image and in a second direction so that the powder moves in a direction opposite to the latent image supporter at a non-image portion of the latent image.Type: GrantFiled: March 24, 2003Date of Patent: May 31, 2005Assignee: Ricoh Company, Ltd.Inventors: Katsuo Sakai, Masanori Horike, Yohichiro Miyaguchi, Nobuaki Kondoh
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Patent number: 6871035Abstract: A developing apparatus includes a developer carrying member for carrying a developer; and a developer feeding member, disposed close to or in contact to the developer carrying member, for supplying a developer to the developer carrying member, the developer feeding member being in the form of a wire and is adapted to be supplied with a voltage which is effective to electrically charge the developer to a regular polarity and which is higher than a discharge starling voltage at which electric discharge starts between the developer carrying member and the developer feeding member.Type: GrantFiled: May 21, 2003Date of Patent: March 22, 2005Assignee: Canon Kabushiki KaishaInventor: Ken Nakagawa
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Patent number: 6829447Abstract: A developing apparatus includes developer carrying member for carrying a developer; wherein the developer carrying member is supplied with a developing voltage comprising a superimposed DC voltage component and AC voltage component to develop an electrostatic latent image formed on an image bearing member; switching means for switching an image density of a developed image on the image bearing member; wherein when the image density of the developed image is made higher than a predetermined image density in accordance with an output of the switching means, the frequency of the AC voltage component is made higher than a predetermined frequency.Type: GrantFiled: December 10, 2001Date of Patent: December 7, 2004Assignee: Canon Kabushiki KaishaInventor: Keiji Okano
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Patent number: 6829446Abstract: An image forming device includes a development section which has a blade for applying electrons generated in its photoelectric surface due to a photoelectric effect to a toner so as to charge the toner; an ultraviolet irradiator for irradiating the photoelectric surface with light; a development roller for holding the toner thus charged, and performing carriage of the toner to a photoconductive drum having an electrostatic latent image on a surface; wherein the electrostatic latent image on the photoconductive drum is developed by the charged toner. The development section further includes a control section for performing control of application of a voltage to the ultraviolet irradiator, application of a voltage to the photoelectric surface, application of a voltage to the development roller, and beginning of the carriage of the toner by the development roller, at predetermined timings, respectively.Type: GrantFiled: April 30, 2003Date of Patent: December 7, 2004Assignee: Sharp Kabushiki KaishaInventors: Kiyoshi Toizumi, Taisuke Kamimura, Toshimitsu Gotoh
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Publication number: 20040234300Abstract: A method of forming an image includes the steps of providing a development bias having a DC component and an AC component superposed on one another and applying the development bias to a developer carrying member. The AC component is provided by superposing a waveform at a second frequency on a waveform at a first frequency in synchronism with each other. The second frequency is an odd multiple of the first frequency.Type: ApplicationFiled: January 14, 2004Publication date: November 25, 2004Applicant: SEIKO EPSON CORPORATIONInventor: Takehiko Okamura
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Publication number: 20040228661Abstract: The electrophotographic image formation apparatus of the present invention adopts a developer roller, which is made of aluminum and has an aluminum oxide film of at least 5 &mgr;m in thickness formed on surface thereof. In the image formation apparatus, a gap between the developer roller and a photoreceptor drum 3 is set in a range of 150 to 300 &mgr;m. The image formation method of the present invention regulates a frequency of AC voltage in a non-development state to be higher than that in a development state, when an AC voltage is applied onto the developer roller to cause flight of toner from the developer roller to the photoreceptor, and selectively makes charged toner fly onto the electrostatic latent image for development. The present invention provides the effective development technique to prevent leakage of the applied voltage between the developer roller and the photoreceptor drum.Type: ApplicationFiled: April 1, 2004Publication date: November 18, 2004Inventors: Masashi Fujishima, Shoichi Sakata
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Patent number: 6810223Abstract: A method of forming an image in a developing apparatus of an image forming apparatus and an image forming apparatus including a retrieving/auxiliary developing roller being in contact with the circumference of the photosensitive drum to retrieve or collect toner remaining on a region other than an image region of the circumference of the photosensitive drum and to first develop the latent electrostatic image, a first toner layer control member uniformly re-distributing the remnant toner and electrifying toner on the circumference of the retrieving/auxiliary developing roller and a developing roller having a gap with the circumference of the photosensitive drum to secondly develop the firstly developed latent electrostatic image so as to completely visualize the latent electrostatic image, a supply roller supplying toner to the developing roller, and a second toner layer control member for regularly coating the toner, which is supplied by the supply roller, throughout the circumference of the developing rollerType: GrantFiled: September 30, 2002Date of Patent: October 26, 2004Assignee: Samsung Electronics Co., Ltd.Inventors: Jong-moon Eun, Duck-hee Lee
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Patent number: 6803542Abstract: A thermal processor for heat processing exposed thermographic media comprising: a heated drum for heating thermographic media brought into contact with the drum; a centrally located assembly for supporting the drum for rotation; a plurality of spaced rollers located around a segment of the drum for holding media into contact with the drum; and a plate assembly for mounting the plurality of rollers for movement between a first position in contact with the drum and a second position out of contact with the drum, the plate assembly having first and second spaced alignment plates having circular features that align with the bearing assembly when the plate assembly is in the first position, whereby the rollers are aligned with the drum.Type: GrantFiled: February 28, 2003Date of Patent: October 12, 2004Assignee: Eastman Kodak CompanyInventor: Bradley B. Rassatt
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Patent number: 6782226Abstract: A developing device includes a toner bearing member holding a toner on its surface for conveyance of the toner to a development region where the toner bearing member opposes an image bearing member via a predetermined gap therebetween; a regulating member pressed against the surface of the toner bearing member for regulation of the amount of toner conveyed to the development region; and a developing bias source for applying an alternating electric field between the toner bearing member and the image bearing member. The developing device features the use of the toner bearing member including a conductive substrate formed with an elastic layer, an intermediate layer and a surface layer on the surface thereof, respective volume resistances &rgr;1, &rgr;2 and &rgr;3 of which layers satisfy a condition &rgr;2≦&rgr;1≦&rgr;3, the toner bearing member having an arithmetic average surface roughness in the range of 0.8 to 2.5 &mgr;m, and the use of the toner having a volume-average particle size of 3 to 8 &mgr;m.Type: GrantFiled: February 19, 2003Date of Patent: August 24, 2004Assignee: Minolta Co., Ltd.Inventors: Junji Machida, Hidetoshi Miyamoto, Tetsumaru Fujita, Masahiko Matsuura, Yoshiko Yaoi, Makoto Shimazoe, Shuichi Nakagawa
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Publication number: 20040146312Abstract: An image forming apparatus includes a plurality of developing devices, each of which includes a developer carrying member for carrying a developer to develop an electrostatic image formed on an image bearing member with a developer, and a developer regulating member for regulating the developer carried on the developer carrying member; common voltage applying means for applying voltages to the developer regulating members, wherein the voltages applied to the developer carrying members are variable independently from each other, and when at least one of the voltages varies, the voltage applied by said voltage applying means is capable of being changed.Type: ApplicationFiled: November 18, 2003Publication date: July 29, 2004Applicant: Canon Kabushiki KaishaInventors: Masanobu Saito, Seiji Yamaguchi, Yasunari Watanabe, Kazunori Hashimoto
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Publication number: 20040136741Abstract: A developing device used with an electrophotographic image forming apparatus and developing method thereof includes a power supplying unit which applies a first electric field to a toner transfer body and a supplying member so that the toner is supplied to the toner transfer body when a development operation is performed, and applies a second electric field to the toner transfer body and the supplying member so that the toner is removed from the toner transfer body when the development operation is not performed, by varying a developing bias and a supplying bias.Type: ApplicationFiled: October 8, 2003Publication date: July 15, 2004Inventor: Duck-hee Lee
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Patent number: 6751423Abstract: A developing apparatus includes a developer carrying member for carrying a developer to develop an electrostatic image formed on an image bearing member with the developer; a developer regulating member regulates an amount of the developer carried on the developer carrying member; and a controller for controlling a potential difference between the developer carrying member and the developer regulating member such that the potential difference is larger in at least a part of non-developing operation than in a developing operation when the developer carrying member carries the developer.Type: GrantFiled: November 18, 2002Date of Patent: June 15, 2004Assignee: Canon Kabushiki KaishaInventors: Katsuhiro Sakaizawa, Satoshi Tsuruya, Seiichi Shinohara, Masahiro Shibata
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Patent number: 6743559Abstract: Disclosed is a toner comprising particles of a polyester resin, an optional colorant, and polypyrrole, wherein said toner particles are prepared by an emulsion aggregation process. Another embodiment of the present invention is directed to a process which comprises (a) generating an electrostatic latent image on an imaging member, and (b) developing the latent image by contacting the imaging member with charged toner particles comprising a polyester resin, an optional colorant, and polypyrrole, wherein said toner particles are prepared by an emulsion aggregation process.Type: GrantFiled: January 23, 2003Date of Patent: June 1, 2004Assignee: Xerox CorporationInventors: James R. Combes, Karen A. Moffat, Maria N. V. McDougall
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Publication number: 20040067078Abstract: A high developing voltage supply apparatus includes solenoid power switches, and a high developing voltage driver selectively outputting a solenoid driving signal to close one of the solenoid power switches to electrically close a corresponding mechanical contact, applying a high developing voltage to one of color development rollers corresponding to the mechanical contact closed and Kased on an image to be printed. A high developing voltage supply supplies the high developing voltage to developing roll shafts of the other color development rollers to stabilize potentials of the developing roll shafts, or, in the alternative, the high developing voltage supply apparatus may include a voltage supply supplying a self-biased voltage to the other color development rollers using the high developing voltage formed with a DC voltage VDC and an AC voltage VAC superimposed.Type: ApplicationFiled: June 23, 2003Publication date: April 8, 2004Applicant: Samsung Electronics Co., Ltd.Inventors: Seung-Deog An, Min-Seon Kim, Woo-Jung Shim
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Patent number: 6699633Abstract: Disclosed is a toner comprising particles of a polyester resin, an optional colorant, and poly(3,4-ethylenedioxythiophene), wherein said toner particles are prepared by an emulsion aggregation process. Another embodiment of the present invention is directed to a process which comprises (a) generating an electrostatic latent image on an imaging member, and (b) developing the latent image by contacting the imaging member with charged toner particles comprising a polyester resin, an optional colorant, and poly(3,4-ethylenedioxythiophene), wherein said toner particles are prepared by an emulsion aggregation process.Type: GrantFiled: January 21, 2003Date of Patent: March 2, 2004Assignee: Xerox CorporationInventors: Karen A. Moffat, Rina Carlini, Maria N. V. McDougall, Dan A. Hays, Jack T. LeStrange
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Patent number: 6694111Abstract: Developing device and method in an image forming apparatus are provided which can make it possible maintaining stabilized image by accurately controlling a toner carry amount. A developing roller is supplied with toner from a toner feed roller to form thereon a toner layer by application of a bias voltage to a toner layer forming member which is in pressing contact with the developing roller. When the operation is started (S1), the current flowing from the toner layer forming blade is detected for a predetermined length of time (S2). Based on the detected result, the current toner carry amount is selected, through the operation of CPU and ROM of a controller, from data D which are previously written in ROM (S3). If the selected toner carry amount is determined as an acceptable level that represents a predetermined amount or more (step 4), printing operation is started as it is.Type: GrantFiled: August 12, 2002Date of Patent: February 17, 2004Assignees: Kabushiki Kaisha Toshiba, Toshiba TEC Kabushiki KaishaInventor: Kouji Hirano
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Patent number: 6689527Abstract: Disclosed is a toner comprising particles of a vinyl resin, an optional colorant, and poly(3,4-ethylenedioxythiophene), wherein said toner particles are prepared by an emulsion aggregation process. Another embodiment of the present invention is directed to a process which comprises (a) generating an electrostatic latent image on an imaging member, and (b) developing the latent image by contacting the imaging member with charged toner particles comprising a vinyl resin, an optional colorant, and poly(3,4-ethylenedioxythiophene), wherein said toner particles are prepared by an emulsion aggregation process.Type: GrantFiled: January 14, 2003Date of Patent: February 10, 2004Assignee: Xerox CorporationInventors: Karen A. Moffat, Maria N. V. McDougall, Rina Carlini, Dan A. Hays, Jack T. LeStrange, Paul J. Gerroir
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Patent number: 6684047Abstract: An image forming apparatus has a latent image carrier on which a latent image is formed. A developer carrier conveys a one-component non-magnetic developer and develops the latent image either in close proximity to or in contact with the latent image carrier. A voltage application unit applies an AC-superimposed bias voltage to the developer carrier. A regulating member abuts against the developer carrier to regulate the thickness of the developer layer on the developer carrier. The regulating member has a semiconductive member provided at the distal end thereof to produce an electric potential difference between the semiconductive member and the developer carrier, to which the AC-superimposed bias voltage is applied, when regulating the thickness of the developer layer on the developer carrier, thereby forming a line-shaped uneven conveying surface. Thus, the occurrence of banding and longitudinal unevenness and stripes is prevented, and fogging and scattering are also prevented.Type: GrantFiled: April 10, 2001Date of Patent: January 27, 2004Assignee: Seiko Epson CorporationInventors: Hidenori Kin, Toru Fujita, Kuniaki Tanaka
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Publication number: 20030175055Abstract: A developing device includes a toner bearing member holding a toner on its surface for conveyance of the toner to a development region where the toner bearing member opposes an image bearing member via a predetermined gap therebetween; a regulating member pressed against the surface of the toner bearing member for regulation of the amount of toner conveyed to the development region; and a developing bias source for applying an alternating electric field between the toner bearing member and the image bearing member. The developing device features the use of the toner bearing member including a conductive substrate formed with an elastic layer, an intermediate layer and a surface layer on the surface thereof, respective volume resistances &rgr;1, &rgr;2 and &rgr;3 of which layers satisfy a condition &rgr;2≦&rgr;1≦&rgr;3, the toner bearing member having an arithmetic average surface roughness in the range of 0.8 to 2.5 &mgr;m, and the use of the toner having a volume-average particle size of 3 to 8 &mgr;m.Type: ApplicationFiled: February 19, 2003Publication date: September 18, 2003Applicant: MINOLTA CO., LTD.Inventors: Junji Machida, Hidetoshi Miyamoto, Tetsumaru Fujita, Masahiko Matsuura, Yoshiko Yaoi, Makoto Shimazoe, Shuichi Nakagawa
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Publication number: 20030128997Abstract: A developing apparatus includes a developer carrying member for carrying a developer to develop an electrostatic image formed on an image bearing member with the developer; a developer regulating member for regulating an amount of the developer carried on the developer carrying member; and control means for controlling a potential difference between the developer carrying member and the developer regulating member such that the potential difference is larger in at least a part of non-developing operation than in a developing operation when the developer carrying member carries the developer control means for controlling a potential difference between the developer carrying member and the developer regulating member such that the potential difference is larger in at least a part of non-developing operation than in a developing operation when the developer carrying member carries the developer.Type: ApplicationFiled: November 18, 2002Publication date: July 10, 2003Applicant: Canon Kabushiki KaishaInventors: Katsuhiro Sakaizawa, Satoshi Tsuruya, Seiichi Shinohara, Masahiro Shibata
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Patent number: 6564027Abstract: An image forming apparatus includes an image bearing member and an electrostatic image forming device, which is adapted to form an electrostatic image on the image bearing member, and which includes an electrifying member contacted with the image bearing member to electrify the image bearing member. The electrifying member includes a first conductive member to which voltage is applied, and a developer carrying member cooperating with the image bearing member to form a nip therebetween and is adapted to carry developer to the nip and to develop the electrostatic image with the developer. The electrifying member also includes a second conductive member to which a voltage is applied. A resistance value between the second conductive member and a developer layer of the developer carried on the developer carrying member is greater than a resistance value between the first conductive member and a surface of the image bearing member.Type: GrantFiled: July 5, 2001Date of Patent: May 13, 2003Assignee: Canon Kabushiki KaishaInventors: Manami Haraguchi, Katsuhiro Sakaizawa
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Patent number: 6542710Abstract: A developing apparatus in which a developer is prevented from attaching to a developer electrifying member. The developing apparatus has a developer carrying body, a regulating member, and a developer carrying member, wherein during a period when developing action is not conducted by the developer carrying body and residual developer is being cleaned, there is a first period during which a first electric field is formed in a direction in which the developer normally charged moves from the developer carrying body to the developer charging member and after the first period there is a second period during which a second electric field is formed in a direction in which the developer normally charged moves from the developer charging member to the developer carrying body.Type: GrantFiled: February 27, 2001Date of Patent: April 1, 2003Assignee: Canon Kabushiki KaishaInventors: Tomomi Kakeshita, Yasuyuki Ishii, Shinji Uehara
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Publication number: 20030059702Abstract: Disclosed is a toner comprising particles of a resin and an optional colorant, said toner particles having coated thereon a polythiophene. Another embodiment of the present invention is directed to a process which comprises (a) generating an electrostatic latent image on an imaging member, and (b) developing the latent image by contacting the imaging member, with charged toner particles comprising a resin and an optional colorant, said toner particles having coated thereon a polythiophene.Type: ApplicationFiled: September 24, 2002Publication date: March 27, 2003Applicant: Xerox CorporationInventors: Karen A. Moffat, Maria N.V. McDougall, Rina Carlini, Dan A. Hays, Jack T. LeStrange, Paul J. Gerroir
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Patent number: 6526238Abstract: A developing device includes a supply member disposed to rotate in contact with a developer carrier to supply developer layer having a predetermined thickness to the developer carrier surface. A layer forming member is disposed to abut against the developer carrier to regulate the layer thickness of the developer so as to form a thin developer layer on the developer carrier. A bias application unit applies an AC-superimposed bias voltage to the developer carrier. A latent image on a latent image carrier is developed with the thin developer layer formed on the developer carrier by the layer forming member. The minimum value of the AC-superimposed bias voltage may be lower than the exposure potential of the latent image carrier, and a maximum value of the bias voltage is to be lower then the charge potential. However, the polarities of the two voltages may be identical.Type: GrantFiled: May 14, 2001Date of Patent: February 25, 2003Assignee: Seiko Epson CorporationInventors: Hidenori Kin, Takehiko Okamura, Yoshiro Koga, Fumio Takagi
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Publication number: 20020164174Abstract: A developing apparatus includes developer carrying member for carrying a developer; wherein the developer carrying member is supplied with a developing voltage comprising a superimposed DC voltage component and AC voltage component to develop an electrostatic latent image formed on an image bearing member; switching means for switching an image density of a developed image on the image bearing member; wherein when the image density of the developed image is made higher than a predetermined image density in accordance with an output of the switching means, the frequency of the AC voltage component is made higher than a predetermined frequency.Type: ApplicationFiled: December 10, 2001Publication date: November 7, 2002Inventor: Keiji Okano
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Patent number: 6470153Abstract: A developing device and a developing method are provided which are capable of steadily supplying sufficiently charged toner to an image bearing member over a long period and always giving a high image quality.Type: GrantFiled: June 26, 2001Date of Patent: October 22, 2002Assignee: Canon Kabushiki KaishaInventor: Shinji Uehara
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Patent number: 6463239Abstract: An apparatus for developing a latent image recorded on an imaging surface, including: a first developer unit for developing a portion of the latent image with a toner of custom color, the first developer unit including a housing defining a reservoir for storing a supply of developer material including conductive toner; a dispenser for dispensing toner of a first color and toner of a second color into the housing, the dispenser including device for mixing toner of the first color and toner of the second color together to form toner of the custom color; a donor member for transporting toner of the custom color on an outer surface of the donor member to a development zone; device for loading a toner layer of the custom color onto the outer surface of the donor member; and device for inductive charging the toner layer onto the outer surface of the donor member prior to the development zone to a predefine charge level; and a second developer unit for developing a remaining portion of the latent image with toner beType: GrantFiled: November 28, 2000Date of Patent: October 8, 2002Assignee: Xerox CorporationInventors: Dan A. Hays, Jack T. LeStrange
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Patent number: 6463246Abstract: It is an exemplified object of the present invention to provide a developer, a development device and its elements, and an image-forming device that can more stably form a high-quality image by a relatively inexpensive and easy means. A noncontact-type development method according to the present invention utilizes a nonmagnetic and single component toner having a volume average particle diameter D (&mgr;m) and an average specific charge q/m (&mgr;C/g), a development roller having a ten-point average surface roughness Rz (&mgr;m), and a blade keeping in contact with the development roller at a blade line pressure Pb (gf/cm). In order to stably form a uniform toner layer dt (&mgr;m) on the development roller, the following relationship is to be met: dt=1.8×{q/m×Rz/(Pb−1)}½×D±0.25 D, and 1.5 D≦dt≦3.5 D.Type: GrantFiled: March 20, 2000Date of Patent: October 8, 2002Assignee: Fujitsu LimitedInventors: Tsuneo Mizuno, Toshihiro Yukawa, Tomoaki Tanaka, Atsushi Tano, Tetsu Takahashi
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Patent number: 6459862Abstract: A developing apparatus has a developer carrying body provided to face an image bearing body. The developer carrying body carries and conveys a developer having toner and carrier to a developing region. A bias applying device applies a developing bias to the developer carrying body, wherein the bias applying device applies to the developer carrying body the developing bias having periodically a voltage portion having alternately a first voltage to generate an electric field to direct toner from the developer carrying body to the image bearing body and a second voltage to generate an electric field to direct the toner from the image bearing body to the developer carrying body and a pause portion to pause applying the alternate voltage, wherein T1 and T2 have a relationship of T1>T2, where T1 is as an applying time period of the first voltage and T2 is an applying time period of the second voltage.Type: GrantFiled: October 16, 2000Date of Patent: October 1, 2002Assignee: Canon Kabushiki KaishaInventors: Yuji Sakemi, Shigeo Kimura, Fumitake Hirobe
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Patent number: 6456814Abstract: A developing device of an image forming apparatus using a two-component developer including toner and carrier includes a developer stirring device to stir the developer to change the toner of the developer, a developing sleeve to rotate and to carry on its surface the developer, and a conductive doctor blade or configured to regulate a thickness of the developer on the developing sleeve. The doctor blade is either grounded or receives a voltage of an electric polarity opposite to that of the toner. An electric potential of the developing sleeve is set to a same electric polarity as that of the toner, and the toner is moved toward a latent image formed on a photoconductor of the image forming apparatus so as to adhere to the latent image by an electric field formed between the developing sleeve and the latent image on the photoconductor.Type: GrantFiled: February 15, 2001Date of Patent: September 24, 2002Assignee: Ricoh Company, Ltd.Inventor: Kazunori Karasawa
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Patent number: 6415127Abstract: A developing apparatus has a developer bearing member for bearing and carrying a nonmagnetic developer, a layer thickness regulating member for regulating a layer thickness of the developer borne by the developer bearing member, developing bias applying device for applying an alternating current voltage to the developer bearing member, and regulating member bias applying device for applying a direct current voltage to the layer thickness regulating member, and wherein |DC1|>|DC2| is satisfied when DC1 is an effective value of the alternating current voltage applied to the developer bearing member and DC2 is a value of the direct current voltage applied to the layer thickness regulating member, the direct current voltage value DC2 has a polarity, which is reverse to a charging polarity of the developer with respect to the effective value DC1.Type: GrantFiled: May 11, 2000Date of Patent: July 2, 2002Assignee: Canon Kabushiki KaishaInventors: Shinya Yamamoto, Hiroshi Sasame, Tetsuya Kobayashi, Kouji Hashimoto, Yasunari Watanabe
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Patent number: 6387581Abstract: Disclosed is a toner comprising particles of a polyester resin, an optional colorant, and poly(3,4-ethylenedioxypyrrole), wherein said toner particles are prepared by an emulsion aggregation process. Another embodiment of the present invention is directed to a process which comprises (a) generating an electrostatic latent image on an imaging member, and (b) developing the latent image by contacting the imaging member with charged toner particles comprising a polyester resin, an optional colorant, and poly(3,4-ethylenedioxypyrrole), wherein said toner particles are prepared by an emulsion aggregation process.Type: GrantFiled: November 28, 2000Date of Patent: May 14, 2002Assignee: Xerox CorporationInventors: Karen A. Moffat, Rina Carlini, Maria N. V. McDougall, Dan A. Hays, Jack T. LeStrange
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Patent number: 6381424Abstract: A charge amount controlling roller serving as a charge amount controlling member is placed to face to a developing roller and is disposed on an upstream side, in a rotation direction of the developing roller, of a developing position at which a photosensitive drum and the developing roller face to each other. The charge amount controlling roller is biased with a voltage having the same polarity as that of non-latent-image portions on the photosensitive drum with respect to the developing roller, thereby reducing extraordinarily charged developing agents, or high charged, low charged, reverse charged toners otherwise causing image defects such as fogs.Type: GrantFiled: September 21, 2000Date of Patent: April 30, 2002Assignee: Fujitsu LimitedInventors: Tetsu Takahashi, Atsushi Tano, Kunihiko Sato
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Patent number: 6360067Abstract: An apparatus for developing a latent image recorded on an imaging surface, including a housing defining a reservoir storing a supply of developer material including conductive toner; a donor member for transporting toner on an outer surface of the donor member to a region in synchronous contact with the imaging surface; a toner layer is loaded onto a region of the outer surface of the donor member; induction charging the toner loaded on the donor member; then the toner layer is conditioned; next the donor member is moved into synchronous contact with imaging member to detach toner from the region of the donor member for developing the latent image; and residual toner discharged and removed from the donor member and returning the toner to the reservoir.Type: GrantFiled: November 28, 2000Date of Patent: March 19, 2002Assignee: Xerox CorporationInventors: Dan A. Hays, Jack T. LeStrange
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Patent number: 6353723Abstract: A method of developing a latent image recorded or an image receiving member with marking particles, to form a developed image, including the steps of moving the surface of the image receiving member at a predetermined process speed; storing a supply of developer material including conductive toner in a reservoir; transporting developer material on a donor member to a development zone adjacent the image receiving member; and; inductive charging the toner layer onto the outer surface of the donor member prior to the development zone to a predefined charge level.Type: GrantFiled: November 28, 2000Date of Patent: March 5, 2002Assignee: Xerox CorporationInventors: Dan A. Hays, Jack T. LeStrange
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Patent number: 6345161Abstract: This invention relates to a non-contact developing method for applying a driving voltage, which is an AC voltage superimposed on a DC offset voltage, to a non-contact developing roller to develop toner, and which prevents the selective developing phenomenon from occurring. The velocity ratio between the flying velocity of toner with a large particle size and the flying velocity of toner with a small particle size changes according to the driving frequency f of the AC voltage (45) applied to the developing roller, so by setting the driving frequency f of the AC component within a range where selective developing of the toner does not occur, it is possible to effectively prevent the selective developing phenomenon from occurring.Type: GrantFiled: December 27, 2000Date of Patent: February 5, 2002Assignee: Fujitsu LimitedInventor: Tsuneo Mizuno
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Publication number: 20020012552Abstract: A developing apparatus includes a developer carrier carrying a developer on its surface, a developer regulating member regulating layer thickness of the developer, and a charge amount control member controlling the charge amount of the developer. The charge amount control member controls the amount of charges of the developer, by causing the developer fly over the developer carrier, using an AC voltage applied between the developer carrier and the charge amount control member, and by applying the electric charges generated by gas electrolytic dissociation caused by the AC voltage. By this structure, a developing apparatus can be provided which can improve stability of development and image quality, without necessitating delicate arrangement of the component materials of the developer.Type: ApplicationFiled: July 26, 2001Publication date: January 31, 2002Inventors: Kazuhiko Furukawa, Hiroyuki Hirakawa, Shigeru Nishio
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Patent number: 6342689Abstract: A heat developing method conveying, to make a heating processing on a heater surface, a heat developable image recording material is disclosed in which an image forming layer and a protection layer are formed using a polymer latex as a binder on one side of a support made prepared by subjecting a polyester biaxially drawn and crystallized with orientation to a thermal relaxation processing at a temperature equal to or higher than 130° C. and equal to or lower than 200° C.Type: GrantFiled: April 14, 2000Date of Patent: January 29, 2002Assignee: Fuji Photo Film Co., Ltd.Inventors: Kunio Ishigaki, Takashi Naoi
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Patent number: 6343201Abstract: A developing apparatus with a developing roller for conveying toners held on its surface to a developing area opposite to an image carrying member, the surface of the developing roller being moved upward from below in the developing area; a regulating member for regulating an amount of the toners to be conveyed to the developing area by the developing roller; a plate-shaped charging member for charging the toners; and a voltage applying device for applying a voltage to the charging member.Type: GrantFiled: July 27, 2000Date of Patent: January 29, 2002Assignee: Minolta Co., Ltd.Inventors: Minoru Wada, Tetsumaru Fujita, Ichiro Demizu, Eiji Gyotoku, Akihiro Kawasaki, Yoichi Fujieda, Hiroshi Goto
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Publication number: 20020009305Abstract: A developing device and a developing method are provided which are capable of steadily supplying sufficiently charged toner to an image bearing member over a long period and always giving a high image quality.Type: ApplicationFiled: June 26, 2001Publication date: January 24, 2002Inventor: Shinji Uehara
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Publication number: 20020009304Abstract: A developing device includes a supply member disposed to rotate in contact with a developer carrier to supply a developer layer having a predetermined thickness to the developer carrier surface. A layer forming member is disposed to abut against the developer carrier to regulate the layer thickness of the developer so as to form a thin developer layer on the developer carrier. A bias application unit applies an AC-superimposed bias voltage to the developer carrier. The AC-superimposed bias voltage is formed by superimposing an alternating current on a DC bias voltage. A latent image on a latent image carrier is developed with the thin developer layer formed on the developer carrier by the layer forming member. The bias application unit sets a maximum value of the AC-superimposed bias voltage lower than the charge potential of the latent image carrier, and sets the DC bias voltage lower than the middle between the charge and exposure potentials of the latent image carrier.Type: ApplicationFiled: May 14, 2001Publication date: January 24, 2002Applicant: SEIKO EPSON CORPORATIONInventors: Hidenori Kin, Takehiko Okamura, Yoshiro Koga, Fumio Takagi
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Publication number: 20010055503Abstract: An image forming apparatus has a latent image carrier on which a latent image is formed. A developer carrier conveys a one-component non-magnetic developer and develops the latent image either in close proximity to or in contact with the latent image carrier. A voltage application unit applies an AC-superimposed bias voltage to the developer carrier. A regulating member abuts against the developer carrier to regulate the thickness of the developer layer on the developer carrier. The regulating member has a semiconductive member provided at the distal end thereof to produce an electric potential difference between the semiconductive member and the developer carrier, to which the AC-superimposed bias voltage is applied, when regulating the thickness of the developer layer on the developer carrier, thereby forming a line-shaped uneven conveying surface. Thus, the occurrence of banding and longitudinal unevenness and stripes is prevented, and fogging and scattering are also prevented.Type: ApplicationFiled: April 10, 2001Publication date: December 27, 2001Inventors: Hidenori Kin, Toru Fujita, Kuniaki Tanaka
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Publication number: 20010055502Abstract: It is an exemplified object of the present invention to provide a development device, development method and image-forming device that can more stably form a high-quality image than was previously possible by a cost-efficient means for stabilizing a toner charge amount, and forming a toner layer having reduced dependence on the toner charge amount. To achieve this object, the inventive development device comprises: a development roller a surface of which is made of electrically resistant material; a blade that comes in contact with the development roller so as to form a layer of developing agents, and has a predetermined thickness on the development roller, and possesses electrical conductivity; a bias power supply that applies a bias to the development roller and the blade; and a resistance provided between the blade and the development bias supply to establish electric connection therebetween.Type: ApplicationFiled: January 22, 2001Publication date: December 27, 2001Applicant: FUJITSU LIMITEDInventor: Tsuneo Mizuno
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Publication number: 20010036372Abstract: An electrophotographic print engine has a variable primary charger and toning bias which places the machine in abnormal reproduction modes in order to provide service and diagnostic information to troubleshoot subsystems involved in the electrophotographic process.Type: ApplicationFiled: March 16, 2001Publication date: November 1, 2001Applicant: Heidelberg Digital L.L.C.Inventors: Matthias Regelsberger, David Hockey, Anne Lairmore
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Publication number: 20010028816Abstract: An object of the present invention is to provide a developing apparatus in which a developer is prevented from attaching to a developer electrifying member. Another object of the present invention is to provide a developing apparatus that has a developer carrying body, a regulating member, and a developer carrying member, wherein in a period when an developing action is not conducted by the developer carrying body, a period that after a first electric field is formed in a direction in which the developer normally charged moves from the developer carrying body to the developer charging member, a second electric field is formed in a direction in which the developer normally charged moves from the developer charging member to the developer carrying body is provided.Type: ApplicationFiled: February 27, 2001Publication date: October 11, 2001Inventors: Tomomi Kakeshita, Yasuyuki Ishii, Shinji Uehara
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Patent number: 6301453Abstract: The invention provides a developing unit, and an image forming apparatus using the same, which is capable of suppressing developer in the middle of a developing process in a developing area from remaining on the surface of an electrostatic latent image carrier when the application of oscillatory bias voltage applied to the developer carrier is stopped and of preventing the inside of the image forming apparatus and each member such as transfer member from being contaminated by the developer. The frequency of the oscillatory bias voltage is controlled so as to be higher than a normal frequency when stopping the application of the oscillating bias voltage.Type: GrantFiled: March 8, 2000Date of Patent: October 9, 2001Assignee: Fuji Xerox Co., Ltd.Inventor: Yasuyuki Tsutsumi