Bias Control Patents (Class 399/55)
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Publication number: 20100303486Abstract: An image forming apparatus includes a toner carrying member for supplying toner to the image bearing member to visualize the latent image; a rotatable toner supply member, contacted to the toner carrying member, for supplying the toner to the toner carrying member, the toner supply member including a surface foam layer; a voltage applying device for applying voltages to the toner carrying member and the toner supply member; a controller for controlling the voltage application apparatus such that A and B have a polarity which is the same as a regular charging polarity of the toner, where A=Vs2?Vd2; B=(Vs2?Vd2)?(Vs1?Vd1); Vd1 is a voltage applied to the toner carrying member during a period in which the latent image is visualized; Vs1 is a voltage applied to the toner supplying member during the period; vd2 is a voltage applied to the toner carrying member during at least a part of a period which is after the visualization of the latent image and before stoppage of rotation of the toner supplying member; and VsType: ApplicationFiled: June 1, 2010Publication date: December 2, 2010Applicant: CANON KABUSHIKI KAISHAInventors: Masahiro Shibata, Masahiro Yoshida, Kazunori Hashimoto, Kazuhiro Okubo, Hisashi Yamauchi
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Publication number: 20100303492Abstract: In an image forming apparatus, a first photoconductor drum for use in at least in a monochrome printing mode is located upstream, in a direction of transport of a medium, of a plurality of second photoconductor drums for use in a color printing mode. A transfer bias for each of transfer members is regulated in such a manner that a transfer bias applied in the monochrome printing mode between a second photoconductor drum located adjacently downstream of the first photoconductor drum and the corresponding transfer member is larger than that applied in the color printing mode. A developing bias for each of the development rollers is regulated in such a manner that an absolute value of a developing bias voltage applied to a development roller corresponding to the first photoconductor drum in the monochrome printing mode is smaller than that applied in the color printing mode.Type: ApplicationFiled: March 25, 2010Publication date: December 2, 2010Applicant: BROTHER KOGYO KABUSHIKI KAISHAInventors: Toshio FURUKAWA, Kensuke MIYAHARA, Yoh NISHIMURA
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Patent number: 7837320Abstract: A liquid droplet ejection apparatus comprising a liquid droplet ejection head that ejects liquid droplets, a conveyor belt that retains and conveys a recording medium while causing the recording medium to face the liquid droplet ejection head, and a charge roll that causes the recording medium to be electrostatically attracted to the conveyor belt. The charge roll and the conveyor belt are configured not to contact each other, and a gap between the charge roll and the conveyor belt is less than the thickness of the recording medium.Type: GrantFiled: June 9, 2006Date of Patent: November 23, 2010Assignee: Fuji Xerox Co., Ltd.Inventors: Satoshi Mohri, Hiroaki Satoh, Koichi Saitoh
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Patent number: 7826754Abstract: An image forming apparatus includes a photosensitive member, a charging device, a developing device, a thickness detecting unit and a parameter setting unit. A photosensitive layer is formed on a surface of the photosensitive member. The charging device charges the photosensitive member. The developing device forms a toner image on the surface of the photosensitive member. The thickness detecting unit detects a thickness of the photosensitive layer on a basis of a value of a current supplied to the charging device. When the thickness detecting unit detects the thickness of the photosensitive layer, the parameter setting unit sets at least one of a charge parameter for the charging device and a development parameter to be different from that used in forming an image on a recording medium by transferring a toner image formed on the surface of the photosensitive member onto the recording medium.Type: GrantFiled: August 15, 2006Date of Patent: November 2, 2010Assignee: Fuji Xerox Co., Ltd.Inventors: Tomokazu Kurita, Kanji Watanabe
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Patent number: 7826756Abstract: A method for controlling an image forming apparatus is disclosed. An image pattern is developed both by a DC developing process using a developing bias voltage of only a DC voltage and by an AC+DC developing process using a developing bias voltage of a DC voltage overlapped with an AC voltage. The densities of the two developed image patterns is compared with each other to implement toner density control.Type: GrantFiled: September 30, 2008Date of Patent: November 2, 2010Assignee: Samsung Electronics Co., Ltd.Inventor: Jun Cheol Bae
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Patent number: 7826758Abstract: An image forming apparatus includes a photosensitive drum to which an electrostatic image is formed and a developing sleeve carrying a developer including toner carrier. An alternating voltage is applied to the sleeve to form an alternating electric field between the sleeve and the drum to develop the electrostatic image with the developer. A relation |K1|<|K2| is satisfied, where K1: a slope at an electric field intensity Ed=|(Vp2?VL)/D|, K2: a slope at an electric field intensity Eb=|(Vp1?VL)/D|, VL: a potential [V] of the electrostatic image at which a maximum density is obtained, Vp1: a peak potential [V] that provides a potential difference to move the toner toward the drum, Vp2: a peak potential [V] that provides a potential difference to move the toner toward the sleeve, and D: a closest distance [m] between the drum and the sleeve.Type: GrantFiled: March 23, 2010Date of Patent: November 2, 2010Assignee: Canon Kabushiki KaishaInventors: Tomoaki Miyazawa, Takeshi Yamamoto, Manami Haraguchi, Kenta Kubo, Juun Horie
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Patent number: 7826774Abstract: The present application is directed to methods for transitioning between color printing and black-only printing in an image forming device. A cartridge is moved between a first position in which color printing may occur and a second position in which black-only printing may occur. In the first position, a color developer unit may be in contact with a color photoconductor unit. The color developer unit may be spaced from the color photoconductor unit in the second position. During the transition, a voltage supplied to the cartridge and a speed of a drive motor driving the cartridge may be adjusted.Type: GrantFiled: March 17, 2008Date of Patent: November 2, 2010Assignee: Lexmark International, Inc.Inventors: William Paul Cook, Ryan David Brockman, Larry Steven Foster, Kermit Arnold Meece, Travis Alan Riggs, Jeffrey Lawrence Tonges, Michael Hayes Wilson
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Patent number: 7821527Abstract: An image forming apparatus, which reduces toner spatter and produces a good quality image when forming a toner image using the direct recording method. An image forming part includes: a toner carrier for carrying toner; and toner controlling means, which is disposed between the toner carrier and recording paper on which the toner is made to adhere, and which has a plurality of toner passage holes, the toner controlling means having a control electrode for controlling the passage of toner on the toner carrier side surface in the area around the toner passage hole, and forming a toner image by causing the toner to fly to the recording paper, and the image forming apparatus having liquid applying/humidifying means for either applying a liquid to or humidifying the imaging surface of the recording paper prior to forming a toner image.Type: GrantFiled: August 7, 2008Date of Patent: October 26, 2010Assignee: Ricoh Company, Ltd.Inventors: Masanori Horike, Yasuo Katano, Masanori Saitoh, Nobuaki Kondoh, Shin Kayahara
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Publication number: 20100266301Abstract: An image forming apparatus includes: an image carrier; a developer carrier configured to supply developer to the image carrier; a power supply unit configured to apply a voltage to the developer carrier; a drive unit configured to rotationally drive the image carrier and developer carrier; a rotation amount determiner configured to determine the amount of rotation of the image carrier or the developer carrier in a predetermined time period; and a drive control unit configured to instruct the drive unit to rotate the image carrier and the developer carrier in a non-printing state, when it is determined that the rotation amount in a printing operation in the predetermined time period was equal to or greater than a threshold.Type: ApplicationFiled: April 8, 2010Publication date: October 21, 2010Applicant: Oki Data CorporationInventor: Hirotaka OHSHIKA
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Publication number: 20100260510Abstract: A developing device includes a developer supporting member for supplying developer to an image supporting member; a developer supplying member for supplying developer to the developer supporting member; and a stirring member disposed to be freely rotatable. The stirring member includes a free end portion arranged to contact with the developer supplying member and a stirring section for stirring developer when the stirring member rotates.Type: ApplicationFiled: April 7, 2010Publication date: October 14, 2010Inventor: Takuya GOTO
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Publication number: 20100260511Abstract: The present invention is directed to clean a collecting member without making toner on the collecting member enter a developing device and to reduce deterioration in throughput accompanying the operation of cleaning the collecting member with a simple configuration. A control unit is provided that executes cleaning operation of transferring toner collected by a cleaning roller to a conveyance belt via a photosensitive drum and collecting the toner by a cleaning device. In the cleaning operation, the control unit develops at least a surface part to which the toner is transferred from the cleaning roller, in the surface portion of the photosensitive drum with the toner by the developing device.Type: ApplicationFiled: April 5, 2010Publication date: October 14, 2010Applicant: CANON KABUSHIKI KAISHAInventors: Katsuhiro Kojima, Masaki Ojima
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Publication number: 20100254725Abstract: Provided are a development apparatus and an image forming apparatus which, in a hybrid development apparatus provided with a plurality of toner carriers, a toner supply capability to supply toner to each toner carrier is controlled independent of development electric fields between the toner carriers and an image carrier, whereby each toner carrier is allowed to exhibit a desired development capability, and even in the case of high speed development, a high quality image is provided. The phases, the frequencies, and/or the duty ratios of the alternating current components of the voltages applied to the plurality of the toner carriers are made to be different, whereby the toner supply amount for each toner carrier from the developer carrier is controlled independently of the development electric fields between the toner carriers and the image carrier.Type: ApplicationFiled: March 25, 2010Publication date: October 7, 2010Inventors: Shigeo UETAKE, Toshiya Natsuhara, Junya Hirayama, Takeshi Maeyama, Makiko Watanabe
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Publication number: 20100239291Abstract: A high-voltage power supply for applying a developing bias to a developing roller of an image forming apparatus is provided. The high-voltage power supply includes: a developing bias application unit that applies a developing bias to the developing roller in accordance with a control voltage that is input therein; a developing bias detection unit that detects the developing bias applied to the developing roller; a control voltage adjustment unit that adjusts the control voltage input to the developing bias application unit such that the developing bias detected by the developing bias detection unit approaches a predetermined target value; and a condensation determination unit that determines condensation of the developing bias application unit based on the control voltage.Type: ApplicationFiled: March 18, 2010Publication date: September 23, 2010Applicant: BROTHER KOGYO KABUSHIKI KAISHAInventors: Kazushi SHUMIYA, Katsumi INUKAI
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Patent number: 7801470Abstract: A developing apparatus, comprises an endless belt shaped donor member; a developer supporting member to carry developer including toner and magnetic carrier and to form a toner layer on the donor member; a first supporting member arranged in the inside of the donor member with a predetermined gap against the developer supporting member and to strain the donor member; a second supporting member arranged in the inside of the donor member with a predetermined gap against the developer supporting member and to strain the donor member; a toner supply bias applying section to apply onto the first supporting member a toner supply bias for supplying toner from the developer supporting member to the donor member; and a toner recovery bias applying section to apply onto the second supporting member a toner recovery bias for recovering toner from the donor member to the developer supporting member.Type: GrantFiled: March 11, 2008Date of Patent: September 21, 2010Assignee: Konica Minolta Business Technologies, Inc.Inventors: Natsuko Minegishi, Seiko Itagaki, Hiroshi Akita
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Publication number: 20100226674Abstract: An image forming apparatus includes a developing section that includes a feed member having a groove, a developer carrier developing with liquid developer fed from the feed member, and a charging member charging the liquid developer carried in the developer carrier. An image carrier carries an image developed by the developing section. An optical sensor includes a light emitting section emitting light to the image developed in the image carrier. A first light receiving section receives light reflected from the image. A second light receiving section is disposed at a position different from that of the first light receiving section. A control section adjusts a developing bias applied to the developer carrier in response to an output signal of the first light receiving section, and controls a bias applied to the charging member by the output signals of the first and second light receiving sections.Type: ApplicationFiled: February 17, 2010Publication date: September 9, 2010Applicant: SEIKO EPSON CORPORATIONInventor: Masahiro FUKAZAWA
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Publication number: 20100226675Abstract: An image forming apparatus is provided. The image forming apparatus includes an accommodating member configured to accommodate developer; a supply member configured to supply the developer of the accommodating member; a developer holding member configured to supply the developer from the supply member to an image holding member; and a voltage controller configured to apply a first predetermined voltage to the supply member and apply a second predetermined voltage to the developer holding member so as to supply the developer from the accommodating member to the electrostatic latent image formed on the image holding member through the supply member and the developer holding member. The voltage controller, when starting to apply a voltage to the supply member, applies an excessive voltage to the supply member, the excessive voltage having a polarity same as the first predetermined voltage and being larger in an absolute value than the first predetermined voltage.Type: ApplicationFiled: March 8, 2010Publication date: September 9, 2010Applicant: Brother Kogyo Kabushiki KaishaInventors: Masatoshi SHIRAKI, Hiroshi Handa, Hiroki Mori
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Patent number: 7792443Abstract: An image forming apparatus includes: an image carrier; a charging member; a developing member; a supplying member; an electrostatic removing unit; a developing member voltage application unit applying a voltage to the developing member; a supplying member voltage application unit applying a voltage to the supplying member; an electrostatic removing unit voltage application unit applying a voltage to the electrostatic removing unit; and a voltage application control unit controlling the voltage applied to the developing member, the voltage applied to the supplying member, and the voltage applied to the electrostatic removing unit. Where the voltage applied to the charging member is changed, the voltage application control unit controls the electrostatic removing unit voltage application unit not to apply the voltage to the electrostatic removing unit.Type: GrantFiled: September 28, 2007Date of Patent: September 7, 2010Assignee: Oki Data CorporationInventor: Tutomu Yamane
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Patent number: 7787785Abstract: An image forming apparatus for forming an image with developing toner on an exposed portion has a mode in which a toner image is automatically output onto a recording material without using exposure by an exposure device. When an inclination adjustment of a corona charging device is performed using an output image on the recoding material, the image forming apparatus can output an image for adjusting the inclination of the charging device that is not affected by variation of an exposing light amount of the exposure device.Type: GrantFiled: June 24, 2008Date of Patent: August 31, 2010Assignee: Canon Kabushiki KaishaInventor: Hiroyuki Kidaka
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Publication number: 20100215389Abstract: An image forming apparatus includes an image carrier, a developer carrier, a runout measurement information storage unit to store runout measurement information of the image carrier and the developer carrier, including runout amounts on the circumference of the image and developer carriers in a development area, a development gap measurement information storage unit to store information obtained by measuring a development gap when runout measurement points of the image and developer carriers face each other, and a development electric field strength control unit to obtain each development electric field strength based on the runout measurement information and the development gap measurement information, and determine control contents of development electric field strength control to cause the entire development electric field strengths to fall within an acceptable range of a target electric field strength to perform the control contents.Type: ApplicationFiled: February 19, 2010Publication date: August 26, 2010Inventors: Masaaki IMAHORI, Masayoshi NAKAYAMA
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Patent number: 7773899Abstract: An amount of toner transfer on a reference pattern is calculated by using an optical detecting unit that detects both regular reflection light and diffuse reflection light from a detection target simultaneously, based on a relative ratio between a value obtained by subtracting a result of multiplying a “diffuse reflection output” by a “minimum value of a ratio between a regular reflection output and the diffuse reflection output” from the “regular reflection output” of the density detection reference pattern, and a value obtained by subtracting a result of multiplying the “diffuse reflection output” by a “minimum value of a ratio between the regular reflection output and the diffuse reflection output” from the “regular reflection output” in the background of a transfer belt or an intermediate transfer body.Type: GrantFiled: February 27, 2009Date of Patent: August 10, 2010Assignee: Ricoh Company, Ltd.Inventor: Hitoshi Ishibashi
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Patent number: 7773900Abstract: The image forming apparatus includes image forming parts, a developing device and a cleaner to clean at least the intermediate transfer material or the transfer device, wherein at the image forming operation starting time, in each image forming part, after starting the charging, the application of the developing bias is started before the top end of the charging portion of the image bearing member surface reaches a developing area in which the image bearing member and the developer bearing member are set against each other, and from among the areas on the image bearing member in which the charging is not yet performed in each image forming part, in case each area having passed the developing area when the developing bias is applied is brought into contact with the intermediate transfer member, the contact area with each area in the intermediate transfer member is controlled without superposing on the intermediate transfer member.Type: GrantFiled: October 30, 2008Date of Patent: August 10, 2010Assignee: Canon Kabushiki KaishaInventor: Tomoyuki Sakamaki
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Publication number: 20100183324Abstract: The image forming apparatus includes a photosensitive drum, developer bearing members to develop a latent image formed on the photosensitive drum into a toner image while bearing developer, a secondary transfer roller to transfer the toner image to a sheet, an operation apparatus to which smoothness of the sheet having the toner image transferred, and a CPU which controls to decrease fog elimination potential difference between non-image portion potential of the photosensitive drum and direct current component potential of bias applied to developer bearing members in a case that smoothness inputted to the operation apparatus is information that the smoothness of the sheet having the toner image formed is equal to or higher than a predetermined smoothness as compared to a case of being lower than the predetermined smoothness.Type: ApplicationFiled: January 6, 2010Publication date: July 22, 2010Applicant: CANON KABUSHIKI KAISHAInventor: Hideki Fujita
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Patent number: 7751736Abstract: In an image density correction method in accordance with an embodiment of the present invention, an image density correction is carried out by obtaining an actual toner amount through obtaining a density of a between-sheet patch image having been formed during continuous printing, reconstructing relational characteristics in which the actual toner amount is associated with each variation in developing biases, by considering that the actual toner amount and a reference toner amount are to be made in agreement, when a determination that the actual toner amount disagrees with the reference toner amount is made, and resetting a developing bias for realizing the reference toner amount based on the reconstructed relational characteristics and the reference toner amount. By this means, a high quality image can be obtained by suppressing color fluctuations with printing efficiency maintained at a high level even if large color fluctuations occur during continuous printing.Type: GrantFiled: May 21, 2008Date of Patent: July 6, 2010Assignee: Kyocera Mita CorporationInventor: Masaru Watanabe
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Patent number: 7734203Abstract: An image formation apparatus including a toner cartridge for holding toner, an image supporting unit, on which an electrostatic latent image corresponding to a toner image is formed, a toner development unit for developing the latent image into the toner image with the toner, a detecting unit for detecting toner concentration of the toner image, and a control unit for controlling an amount of toner adhering to the latent image by adjusting a development bias voltage based on an output of the detecting unit. If control by the control unit based on the detection output of the detecting unit is insufficient, and consumption of the toner is out of a predetermined normal range, the control is carried out by estimating one of toner consumption amount and toner recovery amount in a direction that departs from the predetermined normal range.Type: GrantFiled: February 21, 2008Date of Patent: June 8, 2010Assignee: Ricoh Company, Ltd.Inventor: Hideo Tanaka
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Patent number: 7734205Abstract: An image forming apparatus is provided, which controls an appropriate developer amount for a desired image so that an image defect such as an unclear font or a white area is prevented, resulting in a stable image formation for a long term. A developer regulating member has a resistance value varying depending on a voltage to be applied. A control device changes over the voltage to be applied to the developer regulating member during the image formation according to image information and changes a potential difference between the developer carrying member and the developer regulating member.Type: GrantFiled: June 25, 2008Date of Patent: June 8, 2010Assignee: Canon Kabushiki KaishaInventors: Katsuhiro Sakaizawa, Norio Takahashi, Shuji Moriya, Rie Endo
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Publication number: 20100135685Abstract: An image forming apparatus and a control method thereof are disclosed. A charge unit charges a surface of an organic photo conductor (OPC) to a predetermined electric potential. A developing unit develops an electrostatic latent image formed on the surface of the OPC by coating a developer on the same. A power supply unit supplies power to the charge unit and the developing unit. A control unit regulates the power supplied to the charge unit and the developing unit. After a developing process in the developing unit, the control unit regulates the power applied to at least one of the charge unit and the developing unit so as to collect a residual developer on the surface of the OPC to the developing unit. Accordingly, contamination of the charge unit and the transfer unit can be prevented and an image of a good quality can be achieved.Type: ApplicationFiled: November 23, 2009Publication date: June 3, 2010Applicant: SAMSUNG ELECTRONICS CO., LTD.Inventors: Gun Soo CHANG, Dong Cheol Ahn
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Publication number: 20100129102Abstract: An image forming apparatus includes: a photoconductive drum; a developing roller carrying toner; a DC voltage application portion outputting a DC voltage to be applied to the developing roller, and receiving a feedback voltage; an AC voltage application portion applying an AC voltage to be applied to the developing roller; a detection portion detecting occurrence of electric discharge; a first resistor portion generating a feedback voltage that is fed to the DC voltage application portion; a second resistor portion connected between the DC voltage application portion and the AC voltage application portion, and having a switching portion with which conducting on and off are switchable; and a control portion controlling the switching portion, at the time of printing, to bring the second resistor portion into a conducting state and, at the time of electric discharge detection, to bring the second resistor portion into a non-conducting state.Type: ApplicationFiled: November 16, 2009Publication date: May 27, 2010Applicant: KYOCERA MITA CORPORATIONInventors: Kensuke Fujihara, Tamotsu Shimizu, Ryota Maeda, Kouji Fujii, Tomoyuki Kikuta
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Publication number: 20100129097Abstract: In order to prolong life of a charger, there is provided an image forming device including a photosensitive member, a charger, an exposing unit, a developing unit and a control unit. The charger charges the photosensitive member at a charging position, and the exposing unit exposes the photosensitive member to light and forms an electrostatic latent image on the photosensitive member. The developing unit develops the electrostatic latent image formed on the photosensitive member at a developing position, the developing unit having a developing member that carries thereon developer charged to a polarity, the developing member having a surface potential.Type: ApplicationFiled: November 24, 2009Publication date: May 27, 2010Applicant: Brother Kogyo Kabushiki KaishaInventor: Hiroya FUKUTA
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Patent number: 7720400Abstract: An image forming apparatus comprises: a latent image carrier which carries an electrostatic latent image; a developing unit which visualizes with toner the electrostatic latent image carried by the latent image carrier and forms a toner image; an intermediate transfer medium to which the toner image is transferred from the latent image carrier and which rotates and transports the toner image to a predetermined transfer position and transfers the toner image to a recording medium; a cleaner which abuts on the surface of the intermediate transfer medium and removes toner which adheres to the surface of the intermediate transfer medium after the transfer to the recording medium; and a controller which, assuming that the direction which is orthogonal to the travel direction in which the intermediate transfer medium moves is a width direction, executes toner accumulating processing during which predetermined toner images are formed as end patch images in end areas of the surface of the intermediate transfer mediumType: GrantFiled: June 27, 2006Date of Patent: May 18, 2010Assignee: Seiko Epson CorporationInventors: Keiichi Taguchi, Masahiro Maeda, Tatsuro Osawa
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Patent number: 7715744Abstract: An image forming apparatus includes a photosensitive drum to which an electrostatic image is formed and a developing sleeve carrying a developer including toner carrier. An alternating voltage is applied to the sleeve to form an alternating electric field between the sleeve and the drum to develop the electrostatic image with the developer. A relation |K1|<|K2| is satisfied, where K1: a slope at an electric field intensity Ed=|(Vp2?VL)/D|, K2: a slope at an electric field intensity Eb=|(Vp1?VL)/D|, VL: a potential [V] of the electrostatic image at which a maximum density is obtained, Vp1: a peak potential [V] that provides a potential difference to move the toner toward the drum, Vp2: a peak potential [V] that provides a potential difference to move the toner toward the sleeve, and D: a closest distance [m] between the drum and the sleeve.Type: GrantFiled: April 16, 2008Date of Patent: May 11, 2010Assignee: Canon Kabushiki KaishaInventors: Tomoaki Miyazawa, Takeshi Yamamoto, Manami Haraguchi, Kenta Kubo, Juun Horie
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Publication number: 20100111552Abstract: An image forming apparatus includes a photosensitive member, a developing roller, a toner supply roller, and a charging member. The toner supply roller supplies single-component non-magnetic toner to the developing roller for developing a latent image formed on the photosensitive drum. In a toner cleaning mode, the toner supply roller removes the toner from the developing roller. To this effect, the charging member charges up the toner held on the developing roller. A bias circuit and a controller are further provided, wherein the bias circuit applies bias voltages to the developing roller, supply roller, and charging member, and the controller controls the bias circuit to produce the bias voltages such that a potential difference between the charging member and the supply roller is greater than a potential difference between the developing roller and the supply roller in the toner cleaning mode.Type: ApplicationFiled: October 28, 2009Publication date: May 6, 2010Applicant: BROTHER KOGYO KABUSHIKI KAISHAInventors: Masatoshi Shiraki, Hiroshi Handa, Hiroki Mori
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Publication number: 20100111551Abstract: An image forming apparatus has: a photoconductive drum that rotates; a developing roller that carries toner to be charged and to which a first voltage application portion outputting an AC voltage is connected; a contact member that makes contact with the photoconductive drum to remove residual toner; a detection portion for detecting occurrence of electric discharge between the developing roller and the photoconductive drum; and a developing unit that feeds toner to the developing roller, that supports the developing roller opposite the photoconductive drum with a gap secured in between, and that feeds toner to the developing roller with prescribed timing and for a prescribed time during electric discharge detection.Type: ApplicationFiled: October 27, 2009Publication date: May 6, 2010Applicant: KYOCERA MITA CORPORATIONInventors: Kensuke Fujihara, Tomatsu Shimizu, Ryota Maeda, Koji Fujii
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Publication number: 20100092196Abstract: A developing cartridge includes: a developing roller for developing an electrostatic latent image of a photoconductor with a toner; and a developing tank for storing the toner to be supplied to the developing roller, the developing tank including: a toner receiving port for receiving the toner to be stored; a shutter having a function for sliding to open and close the toner receiving port, the shutter being adapted to be maintained in a closed state by an electrically-releasing adhesive; and a pair of conductive member for supplying an electric current to the electrically-releasing adhesive to open the shutter.Type: ApplicationFiled: October 6, 2009Publication date: April 15, 2010Inventor: Shinya MIMURA
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Publication number: 20100092197Abstract: An image forming apparatus performs a control sequence in which an AC voltage having a peak-to-peak voltage is applied to a charging member so that a relationship between an absolute value of a surface potential of an image bearing member at a portion under a transfer residual toner remaining on the image bearing member which has been electrically charged by the charging member during non-image formation and an absolute value of a surface potential of a developer carrying member is reversed with respect to a relationship between these absolute values during image formation.Type: ApplicationFiled: December 15, 2009Publication date: April 15, 2010Applicant: CANON KABUSHIKI KAISHAInventor: Tadanobu Yoshikawa
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Patent number: 7697873Abstract: In a development apparatus of the hybrid method using a component developer, a development apparatus and a development method are provided that prevent the reduction of density or the occurrence of residual images (ghost images) and can carry out good image forming over a long period of time. A development apparatus has the feature that the surfaces of the toner supporting member and the developer supporting member move in a mutually opposite direction at the part where they are opposite to each others. The development apparatus further employs an electric field in the closest part applied in a direction to recover the toner from the toner supporting member to the developing supporting member, wherein the magnitude of the electric field is in the range from 2.5×106 V/m to 5×106 V/m. The developer of the development apparatus is such that its share (PD) in the space of the closest part of the opposing portion satisfies the following relationship: 0.09?PD?650×Dss.Type: GrantFiled: February 26, 2007Date of Patent: April 13, 2010Assignee: Konica Minolta Business Technologies, Inc.Inventors: Masahiko Matsuura, Toshiya Natsuhara, Junya Hirayama, Takeshi Maeyama, Shigeo Uetake
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Publication number: 20100086323Abstract: An image forming apparatus includes: a supplying section for supplying developer; a first developing roller including plural magnetic poles and a first sleeve arranged rotatable to the first developing roller; a second developing roller including plural magnetic poles and a second sleeve arranged rotatable to the second developing roller, the second developing roller arranged adjacent to the first developing roller and parallel to the same; an electrode arranged between the first and second developing rollers; and a voltage applying unit for applying bias voltages each having different electric potential corresponding to the first developing roller, the second developing roller and the electrode, wherein an absolute value of the bias voltage to be applied to the electrode is larger than that of the bias voltage to be applied to the first developing roller and smaller than that of the bias voltage to be applied to the second developing roller.Type: ApplicationFiled: October 7, 2009Publication date: April 8, 2010Applicant: KONICA MINOLTA BUSINESS TECHNOLOGIES, INC.Inventors: Hiroyuki SAITO, Seiko ITAGAKI, Hiroshi AKITA, Natsuko MINEGISHI
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Patent number: 7692804Abstract: An image forming apparatus operates in a first image formation mode for forming an image on an image bearing member by using developer under a first predetermined image forming condition and a second image formation mode for forming an image on an image bearing member by using developer under a second image forming condition which is different from the first predetermined image forming condition. The apparatus is set so that the amount of consumption of developer for forming an image in the second image formation mode is smaller than the amount of consumption used for forming an identical image in the first image formation mode.Type: GrantFiled: May 14, 2004Date of Patent: April 6, 2010Assignee: Canon Kabushiki KaishaInventors: Norihito Naito, Yasunao Otomo, Hideaki Hasegawa, Nobuo Oshima
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Patent number: 7684717Abstract: An image forming apparatus includes a developing contrast voltage controller to control a developing contrast voltage so as to obtain a desired image density, a transfer condition controller to control transfer conditions for transferring a toner image, an environment sensor to detect an environment, and a correcting coefficient setting unit to refer to a database for pre-registering correcting coefficients to correct the transfer conditions corresponding to the developing contrast voltage and environment and set the correcting coefficients on the basis of the developing contrast voltage controlled by the developing contrast voltage controller and the environment detected by the environment sensor.Type: GrantFiled: December 29, 2006Date of Patent: March 23, 2010Assignees: Kabushiki Kaisha Toshiba, Toshiba Tec Kabushiki KaishaInventors: Takao Izumi, Masato Ogasawara
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Publication number: 20100067932Abstract: An image forming apparatus includes an image carrier; an exposure unit configured to form an electrostatic latent image on the image carrier; a developing unit including a toner containing unit configured to accommodate a predetermined amount of toner, a toner supply unit configured to supply replenishment toner into the toner containing unit, a stirring unit configured to stir the toner to impart electric charge to the toner, a toner carrying member configured to carry the toner charged by the stirring unit, and a bias applying unit configured to apply a developing bias to the toner carrying member to develop the electrostatic latent image formed on the image carrier with the toner carried by the toner carrying member; a density sensor configured to detect a density of a toner pattern developed by the developing unit; and a control unit configured to control an amount of the toner supplied to the toner containing unit.Type: ApplicationFiled: September 11, 2009Publication date: March 18, 2010Applicant: CANON KABUSHIKI KAISHAInventor: Motohiro Fujiwara
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Publication number: 20100061749Abstract: An image forming apparatus includes a developer bearing member configured to bear a developer to develop a latent image, a developer regulating member configured to regulate an amount of the developer carried on the bearing member, a voltage application unit that can apply a plurality of direct current voltages of different values between the bearing member and the regulating member, and a current detection unit that can detect a plurality of direct currents of different values flowing in the regulating member when the voltage application unit applies the plurality of direct current voltages, wherein the image forming apparatus sets a direct current voltage value Vb applied by the voltage application unit when developing the latent image, so that the following expression is satisfied: |Vb|>|Vbmin|, where Vbmin indicates a direct current voltage value when the direct current detected by the current detection unit is a minimum value.Type: ApplicationFiled: September 2, 2009Publication date: March 11, 2010Applicant: CANON KABUSHIKI KAISHAInventors: Kazunari Hagiwara, Norio Takahashi, Katsuhiro Sakaizawa, Rie Endo
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Publication number: 20100061751Abstract: The present invention provides an image forming apparatus, which is able to prevent the adherence of toner on the surface of toner controlling means and around a toner passage hole, and to stably carry out toner passage ON/OFF control when forming an image using the direct recording method. This image forming apparatus includes: a toner carrier; recording medium means; toner controlling means, disposed between the toner carrier and recording medium means, and having a plurality of toner passage holes; and cloud electrode means disposed between the toner carrier and toner controlling means, a toner cloud being formed by applying an AC bias between the toner carrier and cloud electrode means.Type: ApplicationFiled: September 8, 2009Publication date: March 11, 2010Inventors: Masanori HORIKE, Fuyuhiko Matsumoto, Masanori Saitoh, Nobuaki Kondoh, Shin Kayahara, Osamu Endou, Tomoko Takahashi
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Publication number: 20100061750Abstract: An image forming apparatus includes a image bearing member (drum); a developing device for forming a developing portion at which an electrostatic latent image formed on the drum is developed with toner; a toner supply device for supplying toner to the developing device; a density detecting portion for detecting a density of a control toner image formed on the drum; a toner ratio detecting portion for detecting a toner ratio in a two component developer contained in the developing device; a transfer member for forming a transfer portion; a charging member for electrically charging the toner image formed by the developing device by being supplied with a bias of an identical polarity to a charge polarity of the toner; an adjusting portion for adjusting an amount of the toner supplied from the toner supply device so that the toner ratio is below a preset lower limit when the toner ratio detected by the toner ratio detecting portion reaches the lower limit; and a bias determining portion for determining, after theType: ApplicationFiled: September 4, 2009Publication date: March 11, 2010Applicant: CANON KABUSHIKI KAISHAInventor: Noriyuki Okada
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Publication number: 20100054770Abstract: An image forming apparatus includes an image supporting member; a developer supporting member for attaching developer to a static latent image formed on a surface of the image supporting member; a developer layer forming member for forming a developer layer on the developer supporting member; a developer supply member for supplying developer to the developer supporting member; a developer supporting member voltage applying unit for applying a voltage to the developer supporting member; a developer supplying member voltage applying unit for applying a voltage to the developer supplying member; and a reset operation processing unit for setting a reset mode over a specific period of time, so that a bias difference in the reset mode between the voltage applied with the developer supporting member voltage applying unit and the voltage applied with the developer supplying member voltage applying unit becomes smaller than that in a printing mode.Type: ApplicationFiled: July 29, 2009Publication date: March 4, 2010Inventor: Tsutomu YAMANE
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Publication number: 20100054780Abstract: An image forming apparatus includes an image bearing member for bearing an electrostatic latent image; a developing device including a developer carrying member for carrying a developer and developing an electrostatic latent image formed on the image bearing member, and a supplying member for contacting to the developer carrying member to supply the developer to the developer carrying member; and a control device for controlling Vdr and Vrs such that Vrs relative to Vdr increases in a direction of a polarity which is the same as a polarity of the developer with the decrease of an absolute value S, where S is a difference between a peripheral speed Sopc of a surface of the image bearing member and a peripheral speed Sdr of the surface of the developer carrying member, Vrs is a voltage applied to the supplying member, and Vdr is a voltage applied to the developer carrying member.Type: ApplicationFiled: August 27, 2009Publication date: March 4, 2010Applicant: CANON KABUSHIKI KAISHAInventors: Takuya Kitamura, Kohei Matsuda, Hideaki Hasegawa
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Patent number: 7672625Abstract: A developing device, process cartridge, and image forming apparatus that use ETH development, and are capable of forming good multi-color images with a simple construction, and are capable of preventing the dispersal of powder. The developing device is for developing latent images on a latent image carrying member by applying powder to the latent image carrying member, and comprises: a transport member disposed in opposition to the latent image carrying member and having a plurality of transport electrodes that generate a progressive wave electric field to move the powder; a voltage supply device for applying a multi-phase voltage to the transport electrodes; and a transport member surface potential determination device for determining the surface potential of the transport member.Type: GrantFiled: March 5, 2007Date of Patent: March 2, 2010Assignee: Ricoh Company, Ltd.Inventors: Tomoko Takahashi, Katsuhiro Aoki, Hideki Zemba
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Patent number: 7672604Abstract: An image forming apparatus having a developing apparatus using a development system in which toner is moved by means of a traveling wave electric field. The image forming apparatus comprises a plurality of developing apparatuses having toner conveyance members which convey toner by means of a phase-shift electric field created by voltages of n phases applied to a plurality of electrodes, to a region opposing an image carrier on which an electrostatic latent image is formed; and a voltage application device which applies a voltage having an average potential value between the potential of the image portions of the latent image on the image carrier and the non-image portions of same, to the electrodes of the toner conveyance members of the respective developing apparatuses.Type: GrantFiled: March 16, 2006Date of Patent: March 2, 2010Assignee: Ricoh Company, Ltd.Inventors: Tomoko Takahashi, Masanori Horike, Katsuo Sakai, Yohichiroh Miyaguchi, Nobuaki Kondoh
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Patent number: 7668471Abstract: An image forming apparatus including a latent image bearing member; a developing device configured to develop a latent image on the image bearing member with a two-component developer; a development potential forming device configured to form a development potential; a toner replenishing device configured to supply the toner to the developing device; a toner concentration detecting device configured to detect and output the concentration of the toner in the developer; a toner concentration controlling device configured to compare the toner concentration output with a toner concentration target to control the toner concentration; an information detecting device configured to obtain information to determine the replacement amount of the toner in the developing device in a predetermined period of time; and a development potential correcting device configured to adjust the development potential on the basis of the information obtained by the information detecting device.Type: GrantFiled: May 14, 2007Date of Patent: February 23, 2010Assignee: Ricoh Company LimitedInventors: Nobutaka Takeuchi, Shin Hasegawa, Kohta Fujimori, Kayoko Tanaka, Yushi Hirayama
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Publication number: 20100040387Abstract: The invention provides a wet development device, wet development method and image forming apparatus having the device by which appropriate cleaning can be performed, the wear of the blade or developing roller can be reduced, and good images can be obtained without toner contamination even when the amount of toner for development or that of electric charge of the toner is changed for changing the density or gradation of image or type of paper. The toner in the developer is electrically charged to an arbitral charging amount by a discharging section and provided for the development and the charge of the toner is eliminated after development by that a discharging section is provided before cleaning the developer remaining on the developing roller and the output of the discharging section is appropriately controlled corresponding to the output of the discharging section.Type: ApplicationFiled: July 28, 2009Publication date: February 18, 2010Inventor: Atsuto Hirai
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Patent number: 7654663Abstract: A printing device includes an image receptor adapted to have formed thereon an inked image layer, a transfer roller, and a transfer roller biasing system. The biasing system is structured to displace the transfer roller toward the image receptor upon actuation of a motor, exerting a backing pressure.Type: GrantFiled: September 30, 2005Date of Patent: February 2, 2010Assignee: Xerox CorporationInventors: David L. Knierim, Michael E. Jones
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Publication number: 20100021189Abstract: An image printing system configured to minimize two-dimensional image quality non-uniformities on printed documents is provided. The image printing system includes a marking engine, a linear array sensor, an image analyzer, and a controller. The marking engine is constructed to print toner images on an image bearing surface moving in a process direction. The marking engine comprising of a toner development system. The linear array sensor is adjacent the image bearing surface and is extending in a cross-process direction. The linear array sensor is configured to scan the toner image on the image bearing surface. The image analyzer is configured to detect a two-dimensional non-uniformity in the toner image. The controller is configured to control at least one control parameter of the toner development system based on the two-dimensional image quality non-uniformity in the toner image that is detected by the linear array sensor.Type: ApplicationFiled: July 22, 2008Publication date: January 28, 2010Applicant: XEROX CORPORATIONInventors: Joseph C. SHEFLIN, Jack T. Lestrange, Martin Edward Hoover