Charging Patents (Class 399/168)
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Patent number: 7209683Abstract: Charging roller has at least a support member and a conductive covering member, the charging roller where a value of tan ? expressed in a ratio of a storage elastic modulus and a loss elastic modulus by dynamic viscoelasticity in a cross sectional direction of the charging roller at 25° C. is 0.2 or more in a range of 1 to 20 kHz and 0.2 or less in a range of 1 to 10 Hz, or a charging roller where the conductive covering member is constructed of two or more layers and a value of tan ? in at least one layer other than a surface layer is 0.2 or more at 10 Hz in a range of 10 to 50° C. and a value of tan ? in a cross sectional direction of the whole charging roller is 0.2 or less at 10 Hz in a range of 10 to 50° C.Type: GrantFiled: May 16, 2006Date of Patent: April 24, 2007Assignee: Canon Kasei Kabushiki KaishaInventors: Hiroshi Abe, Hirobumi Takahashi, Ayumi Okuda, Tomoya Kawakami
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Patent number: 7194224Abstract: The present invention relates to an image forming apparatus, an image forming process and a process cartridge, in which the image quality and the durability of the photoconductor may be enhanced, images may be formed stably even after the repeated usages, and higher quality and higher stability of images may be established due to the superimposed alternating voltage as well as decrease of the charging hazard on the photoconductor. Specifically, the image forming apparatus according to the present invention comprises a photoconductor, latent electrostatic image forming unit, developing unit a transferring unit, and fixing unit, wherein the charging member is of roller shape disposed proximate to the photoconductor, the photoconductor is charged at the charging nip portion formed between the photoconductor and the charging member, in a condition that satisfies the following Equation: 4.4×1014?[(Number of Charged Particles)÷(Circumferential length of the photoconductor)]?17.Type: GrantFiled: August 27, 2004Date of Patent: March 20, 2007Assignee: Ricoh Company, Ltd.Inventors: Tatsuya Niimi, Masami Kadonaga
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Patent number: 7167665Abstract: The present removing system has a feature to remove a left-over toner that is accumulated on a brush that touches a left-over toner on a photoreceptor. More specifically, the present removing system is so arranged that an alternating voltage (superimposing voltage) on which a positive direct current voltage is superimposed is applied onto a conductive brush in accordance with a user's instruction. With this arrangement, even if a positively electrified left-over toner is accumulated on the conductive brush, it is possible to remove the positively electrified left-over toner accumulated on the conductive brush, because a voltage value (positive) applied on the conductive brush in a moment is large. Moreover, because a voltage of the conductive brush becomes negative in a moment, it is possible to remove a negatively electrified left-over toner attached on the conductive brush.Type: GrantFiled: September 25, 2003Date of Patent: January 23, 2007Assignee: Sharp Kabushiki KaishaInventors: Syohji Tomita, Atsuyuki Katoh, Hiroshi Onda, Takashi Mukai, Hiroshi Ishii
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Patent number: 7155146Abstract: An image forming apparatus includes an image bearing member having a photoconductive surface including an image forming area configured to bear an electrostatic latent image and a non-image forming area. A charging roller has a circular cross section with a first radius, the charging roller including a metallic core having a same rotational axis as the charging roller and a charging surface configured to charge the photoconductive surface of the image bearing member.Type: GrantFiled: November 22, 2004Date of Patent: December 26, 2006Assignee: Ricoh Company, Ltd.Inventors: Akio Kosuge, Hiroshi Ono, Kaoru Yoshino
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Patent number: 7151904Abstract: A conductive member includes a conductive supporting body, an electric resistance adjusting layer disposed on a surface of the conductive supporting body, and a space adjusting mechanism including a material different from the electric resistance adjusting layer, which is disposed on the surface of the conductive supporting body and is firmly fixed to an end portion of the electric resistance adjusting layer, wherein the space adjusting mechanism is provided to form a space between an outer surface of the electric resistance adjusting layer and an outer surface of a photoconductor.Type: GrantFiled: September 1, 2004Date of Patent: December 19, 2006Assignee: Ricoh Company, Ltd.Inventors: Yutaka Narita, Makoto Nakamura, Taisuke Tokuwaki, Akiko Tanaka, Tadayuki Ohshima
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Patent number: 7123861Abstract: A charging device charging a photosensitive medium of an image formation apparatus while being in contact with the photosensitive medium, supports both ends of a charging member having a plate-shaped elastic member by a support member, so that the charging member has a semicircular section. A curved surface of the charging member contacts a surface of the photosensitive medium to maintain a predetermined contact nip and a contact linear pressure. The charging device controls a total resistance by adjusting a material, a thickness, a contact area, and a radius of the charging member, and maintains the contact linear pressure and the contact nip from the photosensitive medium. As a result, the charging device can easily adjust an electric resistance, minimizing variations of the contact linear pressure and the contact nip, material and processing expenses can be cut down, and productivity of the charging device is improved.Type: GrantFiled: November 20, 2002Date of Patent: October 17, 2006Assignee: Samsung Electronics Co., Ltd.Inventor: Jong-moon Eun
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Patent number: 7113719Abstract: An image forming apparatus operable to perform functions. The functions include a function involving a printing operation. The apparatus includes an activator for activating a function. A determiner determines whether the activated function is the function involving the printing operation. The apparatus includes an image forming unit for forming an image on a print medium. A fuser can fuse the image on the print medium with heat. A controller controls the fuser to start heating if the activated function involves the printing operation.Type: GrantFiled: November 16, 2004Date of Patent: September 26, 2006Assignee: Canon Kabushiki KaishaInventor: Tsutomu Kubota
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Patent number: 7050742Abstract: Aspects of the invention relate to hard imaging apparatus charging devices, imaging assemblies, imaging assemblies charging methods, and hard imaging device image bearing member charging methods. In one aspect, a hard imaging apparatus charging device is disclosed. The charging device includes first and second end members, and an intermediate member connecting the first and second end members. The intermediate member may have a length corresponding to an imaging area of the image bearing member of the hard imaging apparatus. The intermediate member may be configured to charge the imaging area used to form latent images on the image bearing member during hard imaging operations of the hard imaging apparatus. The first and second end members of the charging device may be configured to maintain a predetermined spaced charging clearance between the intermediate member and the imaging area of the image bearing member.Type: GrantFiled: October 31, 2003Date of Patent: May 23, 2006Assignee: Hewlett-Packard Development Company, L.P.Inventors: Omer Gila, David S. Vejtasa, Michael H. Lee, Thomas Camis, Peter Gysling
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Patent number: 7015938Abstract: Light emitted from an entire surface of a light source is passed selectively through a liquid crystal shutter. The shutter can be controlled to open/close on a pixel basis in response to image data and then selectively passed light is converted into light having a specified wavelength by a nonlinear optical element before impinging on a metal film. The metal film induces and emits its own electrons and forms an electrostatic latent image directly on a dielectric film.Type: GrantFiled: January 20, 2003Date of Patent: March 21, 2006Assignee: Sharp Kabushiki KaishaInventors: Taisuke Kamimura, Kiyoshi Toizumi, Toshimitsu Gotoh
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Patent number: 6990305Abstract: An image forming apparatus of the present invention includes a charging device including a charge roller formed with annular grooves at opposite end portions thereof and configured to charge an image carrier. Annular gap forming members each are fitted in the annular grooves for forming a gap between the charge roller and the image carrier. The gap forming members each have an area of 1.0×10?6 m2 to 3.0×10?6 m2 in a section containing the axis of the charge roller.Type: GrantFiled: June 8, 2005Date of Patent: January 24, 2006Assignee: Ricoh Company, Ltd.Inventors: Akio Kosuge, Toshio Koike, Yutaka Narita
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Patent number: 6962746Abstract: In a conductive member having a support and provided thereon at least one cover layer, the cover layer has a surface layer, and the surface layer contains fine particles. In the surface layer, fine particles present at the surface-layer lower part corresponding to a range within 30% of the total layer thickness from the lowermost plane have an average particle diameter which is larger than the average particle diameter of fine particles present at the surface-layer upper part corresponding to a range within 30% of the total layer thickness from the uppermost plane. A process cartridge and an electrophotographic apparatus have such a conductive member.Type: GrantFiled: April 10, 2003Date of Patent: November 8, 2005Assignees: Canon Kasei Kabushiki Kaisha, Canon Kabushiki KaishaInventors: Tomohito Taniguchi, Hiroshi Inoue, Hiroyuki Osada, Seiji Tsuru, Hisao Kato, Noriaki Kuroda, Atsushi Ikeda, Toshihiro Otaka, Shinji Doi
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Patent number: 6951688Abstract: The present invention relates to a charging member for charging a surface of a member to be charged in an image forming apparatus, and one aspect of the present invention provides a charging member having an outermost surface layer containing a conductive elastic material. The conductive elastic material comprises a polymer including a polar polymer, primarily including (i) acrylonitrile butadiene rubber, (ii) an ethylene oxide-propylene oxide-allyl glycidyl ether terpolymer, and (iii) a homopolymer of epichlorohydrin. The weights x, y and z of the components (i), (ii) and (iii), respectively, have a relationship of 0.2<y/(x+y+z)?0.5 and 4<y/z?20. This charging member can realize uniform charging and is small in resistance variation, even when used for a long time.Type: GrantFiled: October 7, 2003Date of Patent: October 4, 2005Assignee: Canon Kabushiki KaishaInventors: Hisao Kato, Yoshiaki Nishimura, Jun Murata
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Patent number: 6947680Abstract: In a case where a rotating speed of an intermediate transfer member is reduced during the process of image formation, carriers may adhere to a photosensitive member before the rotating speed of the intermediate transfer member stabilizes. To cope therewith, in changing an image formation speed in accordance with a conveying speed of a recording material on completion of primary transfer, a developing rotary is rotated so as to keep any developing device off a developing position. Consequently, a situation in which the carriers adhere to an image bearing member can be avoided. At the same time, stopping a charging operation of a charger enables a longer service life of the image bearing member.Type: GrantFiled: March 8, 2004Date of Patent: September 20, 2005Assignee: Canon Kabushiki KaishaInventors: Yushi Oka, Akihiko Sato, Shinichi Takata, Shigemichi Hamano, Toru Ono, Kenji Morita
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Patent number: 6939614Abstract: The present invention is directed to an image-fixing member which has excellent heat-resistance, wear resistance, and mold releasability and which performs heating or pressurizing for fixing an image on a recording medium. The preset invention also provides an image-fixing apparatus and image-forming apparatus using the image-fixing member. The image-fixing member of the present invention has a surface layer formed from a heat-resistant resin a nitrogen-containing heat-resistant principal chain segment and a side chain segment having a polysiloxane structure. The heat-resistant resin can also be contained in other portion than the surface layer.Type: GrantFiled: June 10, 2003Date of Patent: September 6, 2005Assignee: Ricoh Company, Ltd.Inventor: Kunihiko Tomita
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Patent number: 6917776Abstract: A discharge wire usable in an electrification device includes a tungsten wire subjected to mirror finish processing and an oxidized layer formed by heating the surface of the tungsten wire at a temperature in the range 400 to 600° C., wherein the film has a thickness in the range of 0.01 to 0.3 ?m.Type: GrantFiled: June 9, 2003Date of Patent: July 12, 2005Assignee: Canon Kabushiki KaishaInventors: Tsuyoshi Kunishi, Nobuhiro Hayashi, Toru Kabashima
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Publication number: 20040265005Abstract: A charging apparatus includes a first first magnetic particle carrying member for carrying magnetic particles; a second magnetic particle carrying member for carrying the magnetic particles, the second magnetic particle carrying member being disposed downstream of the first magnetic particle carrying member with respect to a moving direction of a member to be charged, wherein the magnetic particle are commonly used by the first magnetic particle carrying member and the second magnetic particle carrying member, and the member to be charged is electrically charged by contacting the magnetic particles carried on the first magnetic particle carrying member and the second magnetic particle carrying member to the member to be charged; and current measuring means for measuring a current flowing between the first and second magnetic particle carrying members through the magnetic particles which exist between the first and second magnetic particles.Type: ApplicationFiled: May 20, 2004Publication date: December 30, 2004Applicant: Canon Kabushiki KaishaInventors: Hiroyuki Suzuki, Ryo Nakamura
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Publication number: 20040213600Abstract: An image forming apparatus of the present invention includes a movable body to be charged and a charger including a charging member that contacts or adjoins the body to be charged and applies a voltage, including an AC component, to the charging member for thereby charging the body. A protection substance for protecting the surface of the body from deterioration ascribable to charging is caused to exist on the body. The number of particular elements, contained in the protection substance and detected by an X-ray photon spectral analyzer (XPS) in a zone where the charging member charges the body, is held in a particular ratio to the total number of all elements constituting the outermost surface of the body and also detected by the XPS.Type: ApplicationFiled: February 3, 2004Publication date: October 28, 2004Inventors: Kazuhiko Watanabe, Kenji Sugiura, Yasushi Nakazato, Kazuhito Watanabe, Masahiko Shakuto, Daichi Yamaguchi, Yasuo Suzuki, Nozomu Tamoto, Hiroshi Nakai, Takahiko Tokumasu, Kohichi Ohshima, Nekka Matsuura
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Patent number: 6785494Abstract: An image formation apparatus including a photoreceptor, a charger having a charger member for charging the photoreceptor, a latent image write unit for writing an electrostatic latent image onto the photoreceptor charged by the charger, and a developing device having a developer support with a magnetic field production member, for rendering visible the electrostatic latent image written by the latent image write unit with a developer. Further, the charging member of the charger is disposed under effect of a magnetic field produced by the magnetic field production member of the developing device, and the charging member is made of a nonmagnetic material.Type: GrantFiled: January 28, 2002Date of Patent: August 31, 2004Assignee: Fuji Xerox Co., Ltd.Inventors: Kazuya Yamanoi, Shigeo Ohno, Shigeki Nishimura, Yasuyuki Tsutsumi, Ryuichi Yamamoto, Yusuke Kitagawa, Noritaka Ide, Tadashi Kiyama, Masahiro Satoh, Toshio Masubuchi, Hiromitsu Koizumi
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Publication number: 20040136753Abstract: The present invention relates to a charging member for charging a surface of a member to be charged in an image-forming apparatus, and one aspect of the present invention provides a charging member having an outermost surface layer containing a conductive elastic material.Type: ApplicationFiled: October 7, 2003Publication date: July 15, 2004Applicant: CANON KABUSHIKI KAISHAInventors: Hisao Kato, Yoshiaki Nishimura, Jun Murata
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Patent number: 6751427Abstract: A charger of the present invention includes a charging member contacting or adjoining an image carrier for charging the image carrier. A conductive facing member faces a portion of the charging member other than a portion of the same that faces the image carrier. Discharge occurs between the charging member and the facing member to thereby remove impurities deposited on the charging member. An image forming apparatus including the charger is also disclosed.Type: GrantFiled: May 6, 2002Date of Patent: June 15, 2004Assignee: Ricoh Company, Ltd.Inventor: Kenji Sugiura
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Publication number: 20040109706Abstract: An image forming apparatus of the present invention includes a charging device including a charge roller formed with annular grooves at opposite end portions thereof and configured to charge an image carrier. Annular gap forming members each are fitted in the annular grooves for forming a gap between the charge roller and the image carrier. The gap forming members each have an area of 1.0×10−6 m2 to 3.0×10−6 m2 in a section containing the axis of the charge roller.Type: ApplicationFiled: September 15, 2003Publication date: June 10, 2004Inventors: Akio Kosuge, Toshio Koike, Yutaka Narita
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Publication number: 20040091285Abstract: A system for charging a photoconductive surface being suitable use in forming an image on a substrate, the system including: an at least partial vacuum chamber; at least one nanostructure being disposed within the vacuum chamber and suitable for emitting electrons; and, at least one cap disposed with respect to the at least one nanostructure such that electrons emitted from the at least one nanostructure and colliding with the cap cause radiation suitable for charging the photoconductive surface.Type: ApplicationFiled: November 7, 2002Publication date: May 13, 2004Inventor: Howard Lewis
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Patent number: 6728501Abstract: A charger includes a charging member for charging a desired member. The charging member is made up of a conductive support and a film formed on the support and formed of a substance having negative electron affinity. The film affects electrostatic electron discharge at a low voltage and can therefore charge the desired member more efficiently than a substance having electron affinity. In addition, the charger does not affect discharge and therefore reduces ozone.Type: GrantFiled: May 28, 2002Date of Patent: April 27, 2004Assignee: Ricoh Company, Ltd.Inventor: Junichi Sano
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Patent number: 6697587Abstract: A semiconductive rubber composition is provided having superior electrical properties, such as superior uniformity, small voltage dependence, small environmental dependence, and stability with time. In addition, the semiconductive rubber composition can be used for forming a charging member which suppresses contamination of a member to be charged, such as a photosensitive member. In the semiconductive rubber composition, a dispersed domain structure is formed having a polymeric continuous phase composed of an ion conductive rubber material primarily containing a raw rubber A having an intrinsic volume resistivity of 1×1012 &OHgr;·cm or less and a polymeric dispersed phase composed of an electron conductive rubber material and conductive particles mixed therewith.Type: GrantFiled: June 13, 2001Date of Patent: February 24, 2004Assignee: Canon Kabushiki KaishaInventor: Masaaki Harada
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Publication number: 20030219281Abstract: The invention provides a washing method for a charging member by removing the deposited substance on the surface, thus making the charging member reusable. The washing method, for an electrophotographic charging member to be pressed to the surface of a member to be charged thereby charging the member to be charged, has a step of washing the surface of the charging member at least once with an acidic aqueous solution.Type: ApplicationFiled: March 5, 2003Publication date: November 27, 2003Applicant: FUJI XEROX CO., LTD.Inventors: Shinichiro Saito, Kazunari Koga, Toshiaki Murofushi, Akihiko Suzuki, Akihito Suzukl
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Patent number: 6647231Abstract: The present invention discloses: (1) an electrically conductive member including: a cylindrical base body; and electrically conductive powder sealed inside of the cylindrical base body in a substantially flowable state, or (2) an electrically conductive member including: a cylindrical base body; and electrically conductive powder sealed inside of the cylindrical base body so as not to completely fill the inner volume thereof, or (3) an electrically conductive member including: a cylindrical base body; and electrically conductive powder sealed inside of the cylindrical base body so as to fill only from 20 to 95% of the inner volume thereof. Moreover, the present invention discloses an image forming apparatus equipped with any of the electrically conductive members.Type: GrantFiled: March 15, 2002Date of Patent: November 11, 2003Assignee: Fuji Xerox Co., Ltd.Inventor: Eiji Funabashi
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Patent number: 6600888Abstract: A method including: (a) dispensing an electrically conductive liquid into a contact member permeable to the liquid; (b) rubbing the contact member and a surface against each other, at a contact length greater than a tangential contact length, to release the liquid from the contact member to wet the surface with the electrically conductive liquid in a layer ranging in thickness from about 1 to about 100 micrometers; and (c) electrifying the liquid at any time effective for imparting an electrical charge to the surface.Type: GrantFiled: November 2, 2001Date of Patent: July 29, 2003Assignee: Xerox CorporationInventors: Satchidanand Mishra, Zoran D. Popovic, Anthony M. Horgan, Robert C. U. Yu, Geoffrey M. T. Foley, Huoy-Jen Yuh, Eugene A. Swain
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Publication number: 20030113646Abstract: An imaging method utilizing an imaging member containing a supporting substrate, a layer of a charge carrier injecting surface, a hole blocking layer, an optional adhesive layer, a layer of a charge carrier transport material, a layer of an charge carrier generating material, an optional charge trapping layer, a crossed linked silicone rubber, and an electrically insulating overcoating layer. The member is first charged with electrostatic charges of a first polarity, charged a second time with electrostatic charges of a polarity opposite to said first polarity in order to substantially neutralize the charges residing on the electrically insulating surface of the member and exposed to an imagewise pattern of activating electromagnetic radiation whereby an electrostatic latent image is formed. The electrostatic latent image may be developed to form a visible image which may be transferred to a receiver member. The imaging member may be reused after erasure and cleaning.Type: ApplicationFiled: December 14, 2001Publication date: June 19, 2003Applicant: Xerox CorporationInventors: Merlin E. Scharfe, Richard L. Schank, William W. Limburg, Damodar M. Pai, Dale S. Renfer, John F. Yanus, Paul J. DeFeo
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Patent number: 6579473Abstract: An ethylene propylene rubber foam which comprises as the crude rubber, an ethylene propylene rubber having an iodine value of 35 to 45 and a Mooney viscosity ML1+4 at 100° C. of 20 to 50, and which has less compression set and is suitable as a material for a transfer member, a primary transfer member, a secondary transfer member, a cleaning member for image formation bodies, a bias member, a backup member, etc.; an electroconductive ethylene propylene rubber foam which comprises as the crude rubber, an ethylene propylene rubber having an iodine value of 35 to 45 and a Mooney viscosity ML1+4 at 100° C.Type: GrantFiled: October 19, 2000Date of Patent: June 17, 2003Assignee: Bridgestone CorporationInventors: Chikara Yamada, Toshiyuki Osaki, Tadashi Nakajima, Takahiro Kawagoe
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Patent number: 6560419Abstract: In the charging device, a frequency f(Hz) is set so that a frequency f(Hz) of an AC voltage to be applied to a charging member and a movement rate v(mm/sec) of the surface of an image carrier satisfy f(Hz)≧40(1/mm)·v(mm/sec), the charging device positioned in a non-contact state with the surface of the image carrier.Type: GrantFiled: May 29, 2001Date of Patent: May 6, 2003Assignee: Ricoh Company, Ltd.Inventor: Kenji Sugiura
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Patent number: 6555210Abstract: A new charging member which is durable enough to exhibit stable performance over a long period of time without deterioration by the sticking of toner particles. It is characterized by its surface having a universal hardness no higher than 10 N/mm2 at a depth equivalent to the diameter of toner particles.Type: GrantFiled: April 14, 1999Date of Patent: April 29, 2003Assignee: Bridgestone CorporationInventors: Yoshitomo Masuda, Gaku Yakushiji, Takahiro Kawagoe
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Patent number: 6546219Abstract: A charge roller that includes a metal core, an elastic member configured wrapped around the metal core, and film members is disclosed. Each of the film members is wrapped around each end of the elastic member in a circumferential direction of the metal core such that at least a part of each of the film members exists at every position around the ends of the elastic member in an axial direction of the metal core. Portions of the film members do not overlap each other in an radial direction of the metal core.Type: GrantFiled: February 8, 2001Date of Patent: April 8, 2003Assignee: Ricoh Company, Ltd.Inventors: Masumi Sato, Hiroshi Yoshinaga, Yukiko Iwasaki, Hitoshi Ishibashi, Takatsugu Fujishiro, Masami Hiramatsu, Hiroko Hirano
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Patent number: 6534180Abstract: An object of the invention is to provide a charge-imparting member which can be produced at low cost and maintains superior characteristics for a long period of time. The invention provides a charge-imparting member including an elastic layer formed of an epichlorohydrin rubber material and a surface-treated layer formed by use of a surface treatment liquid containing at least one polymer selected from among an acrylic fluoropolymer and an acrylic silicone polymer; a conductivity-imparting agent; and an isocyanate component.Type: GrantFiled: May 16, 2001Date of Patent: March 18, 2003Assignee: Hokushin CorporationInventor: Junya Hoshi
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Patent number: 6493529Abstract: A charging device which charges a body to be charged. At least a pair of linear electrodes is provided on a substrate so as to be close to each other. Walls are provided near the linear electrodes. Each of the walls has a height larger than a line width of each of the linear electrodes. The linear electrodes are surrounded by the walls and the substrate. The charging device alternatively includes a plurality of dielectrics and electrodes disposed along a first direction facing a drum so that the plurality of dielectrics sandwich the plurality of electrodes along a second direction perpendicular to the first direction, the dielectrics have a height larger than a height of the electrodes along the first direction, and at least two neighboring electrodes have different shapes.Type: GrantFiled: July 3, 2000Date of Patent: December 10, 2002Assignee: Ricoh Company, Ltd.Inventors: Kazuhiko Umemura, Tomoaki Sugawara, Tatsuya Sato, Hiroshi Kondo, Shohji Tanaka
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Publication number: 20020181972Abstract: A charger of the present invention includes a charging member for charging a desired member. The charging member is made up of a conductive support and a film formed on the support and formed of a substance having affinity for negative electrons. The film effects electrostatic electron discharge at a low voltage and can therefore charge the desired member more efficiently than a substance having affinity for positive electrons. In addition, the charger does not effect discharge and therefore reduces ozone.Type: ApplicationFiled: May 28, 2002Publication date: December 5, 2002Inventor: Junichi Sano
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Patent number: 6415122Abstract: An image forming method and image forming apparatus in which a toner image formed on an image carrier (11) through steps of discharging, main charging, exposure and development is transferred to a recording medium (S) and then fixed as an image using flash light. The image forming apparatus (10) has a secondary charger (17) for secondarily charging the image carrier to have the same polarity as a polarity given by a main charger (12) and a surface potential larger in absolute value than a surface potential given by the main charger.Type: GrantFiled: November 9, 2000Date of Patent: July 2, 2002Assignee: Toray Industries, Inc.Inventors: Hidetoshi Hara, Shigehiro Hano
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Patent number: 6405007Abstract: Magnetic particles for charging an image-bearing member electrostatically. The charging magnetic particles have magnetic particles, first surface coat layers containing a first surface coating agent and covering the surfaces of the magnetic particles and second surface coat layers containing a second surface coating agent and covering the first surface coat layers. The charging magnetic particles contain magnetic particles for charging which have a maximum chord length of 5 &mgr;m or larger, and the magnetic particles for charging which have a maximum chord length of 5 &mgr;m or larger having a minor-axis length/major-axis length standard deviation of 0.08 or more. Also, a process for producing the charging magnetic particles is disclosed together with a charging member, a process cartridge and an image forming apparatus which make use of the charging magnetic particles.Type: GrantFiled: June 12, 2000Date of Patent: June 11, 2002Assignee: Canon Kabushiki KaishaInventors: Shuichi Aita, Fumihiro Arahira, Kiyoshi Mizoe
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Patent number: 6374071Abstract: A charging device or a transfer device used for an electrophotographic printer includes a charging unit. In this charging unit, a shaft is loosely encased by a conductive elastic cylinder. Further, the conductive elastic cylinder is loosely encased by a seamless charging tube. As to the charging device, the charging unit is pressed against a photosensitive drum. The seamless charging tube and the conductive elastic cylinder are driven to rotate in association with a rotation of the photo sensitive drum. A charging voltage is applied between the seamless charging tube and the photosensitive drum.Type: GrantFiled: November 3, 2000Date of Patent: April 16, 2002Assignee: Keytech Co., Ltd.Inventor: Masamichi Sato
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Publication number: 20020015600Abstract: The present invention provides an image forming apparatus comprising an image bearing member, an electrostatic image forming device adapted to form an electrostatic image on the image bearing member and including an electrifying member contacted with the image bearing member to electrify the image bearing member, the electrifying member having 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 adapted to carry developer to the nip and to develop the electrostatic image with the developer and having a second conductive member to which voltage is applied, and wherein 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: ApplicationFiled: July 5, 2001Publication date: February 7, 2002Inventors: Manami Haraguchi, Katsuhiro Sakaizawa
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Patent number: 6337103Abstract: A process for remanufacturing a charging member having at least two layers on a conductive support is described. The process involves carrying out mechanical abrasion to remove at least a surface layer of the charging member, followed by forming a layer thereon. Also, a charging member remanufactured by the process and a process cartridge having the hanging member are described.Type: GrantFiled: October 12, 1995Date of Patent: January 8, 2002Assignee: Canon Kabushiki KaishaInventors: Hiroshi Inoue, Naoki Fuei
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Publication number: 20020001489Abstract: An image forming machine comprising image bearing means, charging means, exposure means, reversal development means, transfer means, and cleaning means. The transfer means includes a rotationally driven transfer belt, and transfer voltage applicator means for applying a transfer voltage to the back side of the transfer belt. The transfer voltage applicator means applies the transfer voltage to the transfer belt over a predetermined effective transfer width. The face side of the transfer belt is brought into contact with the image bearing means via an image receiving member and directly over a predetermined effective contact width. The effective contact width is larger than an effective charging width and larger than the effective transfer width.Type: ApplicationFiled: June 18, 2001Publication date: January 3, 2002Inventors: Akihiro Ozaki, Hideki Ishida
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Patent number: 6322939Abstract: An image is formed by a process comprising the steps of: preparing a substrate comprising a transparent substrate having formed thereon a transparent electroconductive film and a semiconductor thin film in this order; preparing in a vessel, which can hold an liquid, an aqueous liquid containing a coloring material and an electrodepositable material capable of chemically dissolving or sedimanting/precipitating depending on the change in the pH; connecting a device than can supply an electric current or an electric field in accordance with an image pattern to the transparent electroconductive film of the substrate; fixing the substrate so that the semiconductor thin film is immersed in the aqueous liquid; disposing a counter electrode as another member of an electrode pair in the vessel; disposing a prescribed photomask on the transparent substrate of the substrate; and carrying out light irradiation at the transparent substrate through the photomask so that an electrodeposited film containing the electrodeposiType: GrantFiled: December 29, 1999Date of Patent: November 27, 2001Assignee: Fuji Xerox Co., Ltd.Inventors: Shigemi Ohtsu, Eiichi Akutsu, Lyong Sun Pu
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Publication number: 20010043817Abstract: The value of an AC voltage ingredient applied to charging rollers in the mono-colored black image forming mode is reduced to be smaller than the value applied in the full-colored image forming mode. Accordingly, in the mono-colored black image forming mode, the electric discharge between the charging rollers and photosensitive drums which do not form images is reduced, so that a shaving-off phenomenon on the surfaces of the photosensitive drums can be decreased, and thereby increasing a lifespan of the photosensitive drums.Type: ApplicationFiled: March 6, 2001Publication date: November 22, 2001Inventor: Yoichiro Maebashi
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Patent number: 6308032Abstract: A rotatable charging apparatus includes a length extending between a first end and a second end, with the rotatable charging apparatus centered about an axis parallel to the length. The rotatable charging apparatus outer periphery forms N apparatus positions. One charging device is fixed to each of N−1 apparatus positions. The remaining (Nth) apparatus position is devoid of a charging device, thus forming an “empty” charging device position. A host printing machine selectively causes the rotatable charging apparatus to rotate about its axis thereby selectively position any of its N−1 charging devices to face a proximately-located photosensitive element. When a problem exists with the current charging device, or when the total number of operating hours of the current charging device exceeds a fixed threshold, the printing machine causes the rotatable charging apparatus to rotate from its current charging device to position a new charging device facing the photosensitive element.Type: GrantFiled: September 19, 2000Date of Patent: October 23, 2001Assignee: Xerox CorporationInventors: Scott D. Weber, Kenneth W. Pietrowski, Joseph D. LaRussa, John S. Facci, Heiko Rommelmann, Alberto Rodriguez, Christopher Snelling
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Publication number: 20010028814Abstract: An image forming apparatus includes a movable image bearing member; charging means including a charge member for electrically charging the image bearing member with electroconductive particles between the charge member and the image bearing member; developing means for developing a latent image with toner mixed with electroconductive particles; wherein the latent image is formed on the image bearing member having been charged by the charging means, and a toner image provided by development of the latent image by the developing means is transferred onto a recording material; wherein the electroconductive particles mixed in the toner is carried by the image bearing member and is fed to between the charge member and the image bearing member; and a width A, measured in a direction perpendicular to a moving direction of the image bearing member, in which the electroconductive particle are present between the charge member and the image bearing member, a width B in which the developing means is capable of effectingType: ApplicationFiled: March 1, 2001Publication date: October 11, 2001Inventors: Hiroyuki Oba, Junichi Kato, Yasushi Shimizu, Hiroshi Satoh, Masahiro Yoshida
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Publication number: 20010024761Abstract: An image is formed by a process comprising the steps of: preparing a substrate comprising a transparent substrate having formed thereon a transparent electroconductive film and a semiconductor thin film in this order; preparing in a vessel, which can hold an liquid, an aqueous liquid containing a coloring material and an electrodepositable material capable of chemically dissolving or sedimanting/precipitating depending on the change in the pH; connecting a device than can supply an electric current or an electric field in accordance with an image pattern to the transparent electroconductive film of the substrate; fixing the substrate so that the semiconductor thin film is immersed in the aqueous liquid; disposing a counter electrode as another member of an electrode pair in the vessel; disposing a prescribed photomask on the transparent substrate of the substrate; and carrying out light irradiation at the transparent substrate through the photomask so that an electrodeposited film containing the electrodeposiType: ApplicationFiled: December 29, 1999Publication date: September 27, 2001Inventors: SHIGEMI OHTSU, EIICHI AKUTSU, LYONG SUN PU
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Patent number: 6295428Abstract: What is provided is an image forming apparatus in which a particle carrier is not contaminated with toner. The image forming apparatus comprises an image carrier for carrying a toner image, and charging means for charging the image carrier, the charging means having charged particles to be brought into contact with the image carrier and particle carrier carrying the charged particles and having a resin layer containing a conductive material on its surface.Type: GrantFiled: December 15, 1999Date of Patent: September 25, 2001Assignee: Canon Kabushiki KaishaInventor: Hiroyuki Suzuki
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Patent number: 6219509Abstract: An image forming apparatus has an auxiliary charging device provided near a transfer device side of the charging device for charging an image forming apparatus including an image bearing member bearing an electrostatic image thereon. The charging device charges the image bearing member. The charging device constitutes electrically conductive magnetic particles in contact with the image bearing member to thereby effect charging. The image forming device forms an electrostatic image on the image bearing device charged by the charging device. A developing device develops the electrostatic image on the image bearing member using a toner. A transfer device transfers the toner image on the image bearing member to a transfer material. An auxiliary charging device provided near the transfer means side of the charging device charges the residual toner after transfer to a polarity opposite to a charging polarity of the charging device, wherein the magnetic particles temporarily collect the residual toner.Type: GrantFiled: January 7, 2000Date of Patent: April 17, 2001Assignee: Canon Kabushiki KaishaInventors: Yoshiyuki Komiya, Atsushi Takeda, Fumiteru Gomi, Kouichi Hashimoto
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Patent number: 6165665Abstract: This invention uses a toner which has .vertline.x.vertline..gtoreq.60, wherein a blow-off charge level is defined as x[.mu.c/g], or a toner which has 11.0.ltoreq.log .rho., wherein a volume intrinsic electric resistivity is defined as .rho.[.mu.c/g]. Alternatively, this invention uses a capsulated toner consisting of a core and a shell resin enclosing the outer of the core, characterized in that the shell resin does not comprise a charge control agent (CCA) for controlling a charge level, but the core only comprises said CCA.Type: GrantFiled: February 24, 1999Date of Patent: December 26, 2000Assignee: Oki Data CorporationInventor: Toru Ishihara
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Patent number: RE39517Abstract: This invention uses a toner which has |x|?60, wherein a blow-off charge level is defined as x[?c/g], or a toner which has 11.0?log ?, wherein a volume intrinsic electric resistivity is defined as ?[?c/g]. Alternatively, this invention uses a capsulated toner consisting of a core and a shell resin enclosing the outer of the core, characterized in that the shell resin does not comprise a charge control agent (CCA) for controlling a charge level, but the core only comprises said CCA.Type: GrantFiled: December 26, 2002Date of Patent: March 13, 2007Assignee: Oki Data CorporationInventor: Toru Ishihara