Bias Control Patents (Class 399/55)
  • Patent number: 8311427
    Abstract: An image forming device and method improves image quality by detecting the density of a pattern and adjusting the voltage applied to a developer supply member if necessary in response to the detected density. The pattern can be a medium duty tone pattern, which is relatively sensitive to environmental changes that can affect image density. The density detection pattern can be produced and detected after every predetermined number of sheets are printed, to maintain an acceptable image density during large print jobs. The pattern is formed on the surface of a transferring unit, which transfers the sheets.
    Type: Grant
    Filed: June 8, 2010
    Date of Patent: November 13, 2012
    Assignee: Oki Data Corporation
    Inventor: Hidetaka Mitsunobu
  • Patent number: 8301047
    Abstract: 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: Grant
    Filed: February 19, 2010
    Date of Patent: October 30, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Masaaki Imahori, Masayoshi Nakayama
  • Patent number: 8290408
    Abstract: An improved method and system for non-contact powder image development are provided. The present technique implements a 5-stage jumping development cycle where the initial stage is a momentary over-voltage condition to release the majority of the toner on a donor substrate and the final stage includes the implementation of a decelerating potential to minimize return impact on the donor and therefore toner abuse. It also uses a routine to directly determine improved (e.g. up to optimal) waveform amplitudes and pulse widths based on toner size and q/m, guided by physical insight.
    Type: Grant
    Filed: March 14, 2008
    Date of Patent: October 16, 2012
    Assignees: Xerox Corporation, Palo Alto Research Center Incorporated
    Inventors: Meng H. Lean, Shu Chang, Daniel L. Larner, Armin R. Volkel
  • Patent number: 8285164
    Abstract: A developing device is provided with a developer transporting member for transporting a developer containing a toner and a carrier; a toner transporting member opposite to the developer transporting member and opposite to an electrostatic latent image carrying member; a first electric field forming device, which is composed of a power source for the developer transporting member and a power source for the toner transporting member, for shifting the toner in the developer held onto the developer transporting member to the toner transporting member; and a second electric field forming device for shifting the toner held onto the toner transporting member to an electrostatic latent image on the carrying member. Operation of the first electric field forming device is controlled based on an electric current flowing in the developer transporting member power source, which is detected by a detecting block.
    Type: Grant
    Filed: September 7, 2010
    Date of Patent: October 9, 2012
    Assignee: Konica Minolta Business Technologies, Inc.
    Inventors: Tomoyuki Imura, Kazuhiro Saito, Takuya Okada, Takuya Sasaki, Chikara Tsutsui, Takayuki Takai
  • Patent number: 8285163
    Abstract: 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: Grant
    Filed: March 18, 2010
    Date of Patent: October 9, 2012
    Assignee: Brother Kogyo Kabushiki Kaisha
    Inventors: Kazushi Shumiya, Katsumi Inukai
  • Publication number: 20120251139
    Abstract: An image forming apparatus including: a photosensitive member; a charging member; a developer carrier; a transfer member; a charging control unit that applies a charging bias having the same polarity as a charged polarity of the developers to the charging member; and a transfer control unit that applies a transfer bias having a reverse polarity to the charged polarity of the developers to the transfer member, wherein when the transfer control unit sets the absolute value of the transfer bias to a first value, the charging control unit sets an absolute value of the charging bias to a third value, and wherein when the transfer control unit sets the absolute value of the transfer bias to a second value, the charging control unit sets the absolute value of the charging bias to a fourth value smaller than the third value.
    Type: Application
    Filed: January 31, 2012
    Publication date: October 4, 2012
    Applicant: BROTHER KOGYO KABUSHIKI KAISHA
    Inventor: Hiroshi HANDA
  • Publication number: 20120251146
    Abstract: Methods for printing are provided. In one aspect, the method includes providing a primary imaging member having engine pixel locations with a ratio modulated difference of potentials, establishing a first development difference of potential to form a first net development difference of potential between the first development difference of potential and the engine pixel location and providing a first charged toner such that the first toner develops at the engine pixel location according to the first net development difference of potential. Establishing a second development difference of potential that is greater than the first difference of potential proximate the engine pixel location such that a determined amount of second toner develops at the engine pixel locations. Wherein the range of first toner potentials is such that a determined range of ratios of first toner amounts and the determined second toner amount provide ratio modulated differences of potential.
    Type: Application
    Filed: March 31, 2011
    Publication date: October 4, 2012
    Inventors: Thomas Nathaniel Tombs, Donald Saul Rimai, William Yurich Fowlkes
  • Patent number: 8280268
    Abstract: A developing device is provided with a first transporting member for transporting a developer containing a toner and a carrier; a second transporting member opposite to the first transporting member to interpose a first spatial region therebetween and opposite to an electrostatic latent image carrying member to interpose a second spatial region therebetween; a first electric field forming device, composed of first and second power sources, for shifting the toner in the developer held onto the first transporting member to the second transporting member; and a second electric field forming device, composed of the second power source, for shifting the toner held onto the second transporting member to an electrostatic latent image on the carrying member. The operation of the second electric field forming device is controlled based on electric currents flowing in the first and second power sources, which are detected by first and second detecting blocks, respectively.
    Type: Grant
    Filed: September 7, 2010
    Date of Patent: October 2, 2012
    Assignee: Konica Minolta Business Technologies, Inc.
    Inventors: Tomoyuki Imura, Kazuhiro Saito, Takuya Okada, Takuya Sasaki, Chikara Tsutsui, Takayuki Takai
  • Patent number: 8275299
    Abstract: A transfer unit, which transfers a toner image formed on at least one image support to a printing medium, and an image forming apparatus employing the same. The transfer unit includes: an intermediate transfer body to the toner image from the image support, which has a curved transfer surface and an ASKER-A hardness of from about 25° to 40°; a transfer member, which has an ASKER-C hardness of from about 45° to 70°, and which contacts the intermediate transfer body, with a printing medium being interposed therebetween, and transfers the toner image from the intermediate transfer body to the printing medium. The transfer unit may further include: a de-electrifying member having a DC power and an AC power concurrently applied thereto, to de-electrify the printing.
    Type: Grant
    Filed: October 26, 2010
    Date of Patent: September 25, 2012
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Je-hwan You, Gyeong-ho Park
  • Patent number: 8275276
    Abstract: An image forming device includes a photosensitive member, a charger, an exposing unit, a developing unit and a control unit. The charger charges the photosensitive member, 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 and has a developing member having a surface potential and developer charged to a polarity. The control unit applies a first voltage having a first absolute value to the charger at least during development while applying a second voltage having a second absolute value to the charger during operations other than development. The first voltage, the second voltage and the surface potential have the same polarity as the developer with the first voltage absolute value being greater than the second voltage absolute value which is greater than an absolute value of the surface potential.
    Type: Grant
    Filed: November 24, 2009
    Date of Patent: September 25, 2012
    Assignee: Brother Kogyo Kabushiki Kaisha
    Inventor: Hiroya Fukuta
  • Publication number: 20120237236
    Abstract: Image forming apparatus to expose-scan electrically charged surface of image carrier based on image data in unit of page to form electrostatic latent image, and develop electrostatic latent image at development position on image carrier by using developer carried by developer carrier. The image forming apparatus determines, based on image data of page, first and second partial regions having first and second attributes in page, not overlapping in sub scanning direction, and switches development bias voltage value and/or rotational speed of developer carrier to value for first attribute while electrostatic latent image on image carrier corresponding to first partial region passes through development position, and to value for second attribute while electrostatic latent image corresponding to second partial region passes through development position.
    Type: Application
    Filed: March 8, 2012
    Publication date: September 20, 2012
    Applicant: Konica Minolta Business Technologies, Inc.
    Inventor: Yohei NAKADE
  • Patent number: 8270859
    Abstract: An image forming apparatus and a control method of the image forming apparatus. The image forming apparatus includes a photosensitive medium, a charger to charge the photosensitive medium, an exposing unit to expose light to the photosensitive medium to form a latent image on the photosensitive medium, a developing unit which is disposed opposite to the photosensitive medium to develop the latent image into a visible image, a density sensing unit to sense a density of an area of the photosensitive medium, and a controller to determine whether a preset developing condition corresponds to a background image generating condition based on the density sensed by the density sensing unit and to adjust the developing condition based on the determination.
    Type: Grant
    Filed: September 10, 2009
    Date of Patent: September 18, 2012
    Assignee: SAMSUNG Electronics Co., Ltd.
    Inventor: Han-sang Oh
  • Publication number: 20120230714
    Abstract: A developing apparatus including a developing container for containing developer, the developing container having an opening portion, a developer carrying member for carrying the developer at the opening portion, a detecting member for detecting a developer amount, the detecting member detecting a capacitance between the developer carrying member and the detecting member, and a force receiving portion for receiving a force and moving the developing container between a first position in which a developing operation is performed by the developer carrying member and a second position in which the developing operation is not performed, wherein the capacitance can be detected in the second position, and the detecting member is a rotatable developer supplying member for supplying the developer to the developer carrying member, the developer supplying member including a foam layer in which the developer can enter.
    Type: Application
    Filed: May 25, 2012
    Publication date: September 13, 2012
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Shinya Yamamoto, Takeshi Kawamura
  • Publication number: 20120230706
    Abstract: An image forming apparatus includes an image bearing member to bear a toner image, a transfer device to transfer the toner image onto a recording medium, and a moving device controller to control a moving device that moves the transfer device such that the moving device moves the transfer device to contact the image bearing member during transfer of the toner image on the image bearing member to the recording medium; separates the transfer device from the image bearing member as a toner patch on the image bearing member passes through the transfer area; and maintains the transfer device in contact with the image bearing member from a preceding transfer of a toner image to a succeeding transfer of a toner image during continuous printing, as at least one of areas between successive toner images on the image bearing member without the toner patch passes through the transfer area.
    Type: Application
    Filed: February 22, 2012
    Publication date: September 13, 2012
    Applicant: RICOH COMPANY, LTD.
    Inventor: Ken Yoshida
  • Patent number: 8265500
    Abstract: An image forming apparatus which includes a photosensitive member and an image forming station. The image forming station includes a charging device for charging the member, an exposure device for exposing the member to light, a developing device for developing an electrostatic latent image on the member, and a bias applying device for applying a developing bias. The image forming apparatus also includes, a transfer device for transferring a toner image to a sheet, a setting device for setting an AC voltage, an executing device for executing a test mode, a density detecting device for detecting the density of the test image, and an adjusting device for adjusting an image forming condition for the station. When the executing device executes the test mode, test images can formed at various AC voltages.
    Type: Grant
    Filed: September 8, 2009
    Date of Patent: September 11, 2012
    Assignee: Canon Kabushiki Kaisha
    Inventor: Kenichiro Kitajima
  • Patent number: 8260160
    Abstract: A color image forming apparatus having photosensitive members; developing devices for developing electrostatic latent images formed on the photosensitive members into toner images with developers comprising toner and carriers; toner concentration sensors for detecting toner concentrations of the developers in the respective developing devices; a toner image bearing member for bearing the toner images temporarily; a toner adherence amount sensor for detecting toner adherence amounts of the toner images held on the image bearing member; and a controller for calculating, with respect to the developing devices, individual optimal developing bias voltage ranges within which a target toner adherence amount can be achieved while the toner concentrations of the developers are within a predetermined toner concentration range from a lower limit to an upper limit, so as to specify a common optimal developing bias voltage range that are commonly suitable for all the developing devices to achieve the target toner adherenc
    Type: Grant
    Filed: July 23, 2010
    Date of Patent: September 4, 2012
    Assignee: Konica Minolta Business Technologies, Inc.
    Inventors: Hironori Akashi, Soh Hirota, Mitsuru Obara, Takashi Harashima, Kanako Kibihara
  • Publication number: 20120207496
    Abstract: A representative configuration of an image forming apparatus according to the invention is provided. The image forming apparatus has a plurality of developing devices which develops an electrostatic latent image formed on a photosensitive drum into a toner image using developer of plural colors. The image forming apparatus includes a density sensor which detects the amount of toner of the toner image for each color. In a case where it is determined that the amount of toner of any color departs from a predetermined range based on the detection result of the density sensor, a development condition of the rest developing devices other than the developing device departing from the predetermined range is changed such that the image densities developed by the respective developing devices are equal to each other.
    Type: Application
    Filed: January 20, 2012
    Publication date: August 16, 2012
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Akihiro Noguchi, Fumitake Hirobe, Shigeru Tanaka
  • Publication number: 20120201556
    Abstract: An image forming apparatus includes a photoreceptor, a developing apparatus, a developing bias supply power source, a control section for controlling a developing bias, a density sensor, and an arithmetic section. When an image density adjustment operation is performed, the arithmetic section determines a print-time developing bias in accordance with a detection result obtained by detecting, by the density sensor, a plurality of image density adjustment toner images formed by changing a developing bias. The print-time developing bias is set by the control section when printing is performed. also, In a case where a previous print-time developing bias falls within at least a low range of a predetermined range of the developing bias, the arithmetic section determines the print-time developing bias to a value between a reference developing bias for a target image density and the previous print-time developing bias.
    Type: Application
    Filed: February 1, 2012
    Publication date: August 9, 2012
    Inventors: Masayuki OTSUKA, Takashi Kitagawa, Motoyuki Itoyama
  • Publication number: 20120201555
    Abstract: An image forming apparatus of the invention includes; a cleaning member that collects liquid developer by cleaning a developer carrier; a first transporting path that moves the liquid developer collected by the cleaning member; an oscillating member that applies vibration to the liquid developer transported from the first transporting path; a developer supply unit that stores the liquid developer transported from a first transporting mechanism; a second transporting mechanism that includes a second transporting path that transports the liquid developer stored in the developer supply unit to a developer storage in a developing unit; and a control unit that adjusts a toner charge current applied to the toner charging unit and controls vibration applied to the oscillating member on the basis of the adjusted toner charge current.
    Type: Application
    Filed: January 17, 2012
    Publication date: August 9, 2012
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Kazuhiro NISHIYAMA, Akihiro GOMI, Tsutomu SASAKI, Naotaka HIGUCHI
  • Publication number: 20120201551
    Abstract: An image forming apparatus is provided. The image forming apparatus includes a photosensitive member, a developing roller which carries developer and contacts the photosensitive member, and a control device which is configured to apply, to the developing roller, a developing bias having a direct current component and an alternating current component overlapped with each other so as to supply developer from the developing roller to the photosensitive member. The control device is configured to execute either one of a first mode in which an amplitude of the alternating current component of the developing bias is set with a first set value and a second mode in which the amplitude of the alternating current component of the developing bias is set with a second set value larger than the first set value, based on whether or not a temperature of the developing roller is a first predetermined value or larger.
    Type: Application
    Filed: January 31, 2012
    Publication date: August 9, 2012
    Applicant: BROTHER KOGYO KABUSHIKI KAISHA
    Inventors: Shuichi KATO, Masanari YOSHIKAWA
  • Publication number: 20120195616
    Abstract: An image forming apparatus includes first photosensitive members, first chargers for charging the first photosensitive members, developer carriers for supplying developer to the first photosensitive members, a first charging-bias applying unit that applies charging biases to the first chargers, development-bias applying units for applying development biases to the corresponding developer carriers, a charging-current sensing unit that separately senses a charging current flowing in each of the first chargers, and a control unit that controls the development biases based on the sensed charging current.
    Type: Application
    Filed: January 31, 2012
    Publication date: August 2, 2012
    Applicant: BROTHER KOGYO KABUSHIKI KAISHA
    Inventor: Kensuke MIYAHARA
  • Publication number: 20120195613
    Abstract: Printers are provided. In one aspect, at least one first toner image is formed and transferred onto a receiver to form a composite toner image on a receiver having a second polarity. A second development station of a toner layer balancing system creates a second development difference of potential of a first polarity between a bias member and the first toner at each location of the receiver, to cause a second toner of the second polarity to deposit at individual locations on the receiver in amounts according to the second net development difference of potential at the individual locations such that total amount of first toner and any second toner deposited at each location on the receiver is within a range that is less than a range of first toner amounts on the receiver.
    Type: Application
    Filed: January 31, 2011
    Publication date: August 2, 2012
    Inventor: William Y. Fowlkes
  • Publication number: 20120195614
    Abstract: Methods for printing are provided. In one aspect a primary imaging member having a pattern of engine pixel locations with image modulated differences of potential of a first polarity and with first toner having a first toner difference of potential of a second polarity is moved to a second development station. A second development difference of potential of the first polarity at the second development station forms a second net development difference of the second development difference of potential less any image modulated difference of potential at the individual engine pixel location and less any difference of potential relative to ground of any first toner at the individual engine pixel location. The second development difference of potential is less than the first development difference of potential so that second toner that is different from the first toner, is developed onto the first toner using the second net development difference of potential.
    Type: Application
    Filed: January 31, 2011
    Publication date: August 2, 2012
    Inventor: William Y. Fowlkes
  • Publication number: 20120195615
    Abstract: Printers are provided. In one aspect, at least one first toner image is formed and transferred onto a receiver to form a composite toner image on a receiver having a first polarity. A second development station of a toner layer balancing system creates a second development difference of potential of the first polarity between a bias member and the first toner at each location of the receiver, to cause a second toner of the first polarity to deposit at individual locations on the receiver in amounts according to the second net development difference of potential at the individual locations such that total amount of first toner and any second toner deposited at each location on the receiver is within a range that is less than a range of first toner amounts on the receiver.
    Type: Application
    Filed: January 31, 2011
    Publication date: August 2, 2012
    Inventor: William Y. Fowlkes
  • Publication number: 20120183315
    Abstract: An image forming apparatus which forms an image on an image carrier along with rotation of a developing sleeve that carries a toner and carrier contained in a two-component developer, comprises: forming unit configured to form a density detection toner image on the image carrier using the toner; detection unit configured to detect a density of the density detection toner image formed; prediction unit configured to predict a toner charge amount in the two-component developer; correction unit configured to correct the toner charge amount in the two-component developer using a value obtained from a relationship between the toner charge amount predicted by the prediction unit and the density of the toner image that is detected by the detection unit; and control unit configured, when forming the density detection toner image by the forming unit, to control to increase a development efficiency, compared to image formation based on image data.
    Type: Application
    Filed: January 12, 2012
    Publication date: July 19, 2012
    Applicant: CANON KABUSHIKI KAISHA
    Inventor: Motohiro FUJIWARA
  • Publication number: 20120177390
    Abstract: An image forming cartridge comprises a developing unit configured to hold toner including a developing section configured to use the toner for developing and a supplying section configured to provide the toner to the developing section and a toner cartridge attachable to the developing unit, wherein the toner cartridge contains toner and supplies toner to the developing unit and the toner cartridge includes a stand-by charging unit configured to perform stand-by charge to the toner in the toner cartridge.
    Type: Application
    Filed: March 21, 2012
    Publication date: July 12, 2012
    Applicant: OKI DATA CORPORATION
    Inventor: Yoshio NIIJIMA
  • Patent number: 8208825
    Abstract: An electrostatographic printing machine has a liquid toner supply chain incorporating at least a toner supply device (10), a metering roller (21) and a development member (31) and an image carrying member (41). An electrostatic charging device (33) acts onto the development member to impress an electrostatic charge onto the development member and to induce a voltage thereon with respect to a machine electrical common earth potential. The toner supply roller, the metering roller and the developer member are each electrically connected to the machine electrical common earth potential (37) via a respective voltage regulating or controlling means (25, 27, 35) to regulate or control induced voltages on each of the toner supply roller, the metering roller and the developer member.
    Type: Grant
    Filed: February 11, 2008
    Date of Patent: June 26, 2012
    Assignee: Xeikon IP BV
    Inventor: Minghua Mao
  • Publication number: 20120155901
    Abstract: An image forming apparatus including a control portion which controls a bias to be applied to a charging roller for charging a photosensitive member to a predetermined potential or a developing roller for supplying toner to the photosensitive member, in which the control portion performs a developer install mode for controlling the bias to be applied to the charging roller or the developing roller during replenishment of toner to a developing container to be used for the first time, and at a time of the developer install mode, controls the bias to be applied to the charging roller or the developing roller so as to obtain a developing electric field (Vcont2) for developing toner having an excessive charge amount onto the photosensitive member, which is smaller than a developing electric field (Vcont1) for developing toner onto the photosensitive member at a time of image formation.
    Type: Application
    Filed: December 16, 2011
    Publication date: June 21, 2012
    Applicant: CANON FINETECH INC.
    Inventor: Masashi WAKISAKA
  • Patent number: 8204395
    Abstract: 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: Grant
    Filed: July 28, 2009
    Date of Patent: June 19, 2012
    Assignee: Konica Minolta Holdings, Inc.
    Inventor: Atsuto Hirai
  • Patent number: 8204412
    Abstract: A duty ratio Du (%), denoted by (T2/(T1+T2))×100, is in the range of 60?Du?80; a magnetic carrier has a resistivity ? which decreases in accordance with an increasing electric field strength, and a relative dielectric constant ? which increases in accordance with an increasing electric field strength; a product of a time constant ?0??(s) of electric charge decay in an electric field strength E2D decided by a second peak voltage V2 and a dark potential VD, and an electric field strength E2D satisfies a relation of 20??0?? E2D (s·V/cm); and a time constant ?0??(s) and a relative dielectric constant ? in an electric field strength E1L, which is decided by a first peak voltage V1 and a bright potential VL, satisfy the following relations: ?0??(s)?6.0×10?4, and 30??.
    Type: Grant
    Filed: April 30, 2010
    Date of Patent: June 19, 2012
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kenta Kubo, Takeshi Yamamoto, Manami Haraguchi, Tomoaki Miyazawa, Juun Horie
  • Publication number: 20120148279
    Abstract: A wet-type image forming apparatus includes an image bearing member, a developer bearing member for bearing liquid developer containing toner and carrier liquid on the circumferential surface thereof, a bias applying unit for applying a developing bias to the developer bearing member, a first charging unit for charging the toner in the liquid developer to a first polarity before supplying the liquid developer to the image bearing member, and a second charging unit for reversely charging the toner in residual liquid developer remaining on the circumferential surface of the developer bearing member to a second polarity opposite to the first polarity after the development process. When VD denotes the developing bias and V0 denotes the surface potential of the residual liquid developer when the reverse charging is not performed, a surface potential V of the residual liquid developer after reverse charging satisfies the equation: 0.1?(VD?V)/(V0?VD)?1.0.
    Type: Application
    Filed: December 6, 2011
    Publication date: June 14, 2012
    Applicant: Kyocera Mita Corporation
    Inventor: Tomohisa Soda
  • Patent number: 8200109
    Abstract: 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 the
    Type: Grant
    Filed: September 4, 2009
    Date of Patent: June 12, 2012
    Assignee: Canon Kabushiki Kaisha
    Inventor: Noriyuki Okada
  • Publication number: 20120134697
    Abstract: A development device includes an image carrier configured to develop an electrostatic latent image by using a developer, a development member configured to supply the developer to the image carrier, a developer supply member configured to supply the developer onto a surface of the development member, and a developer restriction member including a contact portion configured to form a developer layer on the surface of the development member while being in contact with the surface. A curvature radius R [mm] of the contact portion of the developer restriction member is 0.17 [mm] to 0.28 [mm], both inclusive, and an ASKER F hardness [°] of the developer supply member is 181.82×R+9.09?F??250×R+130.
    Type: Application
    Filed: November 17, 2011
    Publication date: May 31, 2012
    Applicant: OKI DATA CORPORATION
    Inventor: Junichi KAWASHIMA
  • Patent number: 8190044
    Abstract: 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: Grant
    Filed: August 27, 2009
    Date of Patent: May 29, 2012
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takuya Kitamura, Kohei Matsuda, Hideaki Hasegawa
  • Publication number: 20120114350
    Abstract: An image forming apparatus includes a first rotating unit, an image carrier, an electrostatic latent image forming unit, a third rotating unit, an intermediate transfer body, first and second transfer units, and the following elements. A developing device includes a rotating body, a second rotating unit, plural developing units. A supply unit supplies a bias to a developer carrying member of each developing unit. A setting unit sets the bias to a first condition to develop the latent image of a first color at least while the latent image is being located at the developing position, and sets the bias to a second condition to suppress transferring of the toner in the subsequent developing unit to the image carrier after the second rotating unit starts rotating the rotating body from a waiting position and before stopping rotating the rotating body and locates the subsequent developing unit at the developing position.
    Type: Application
    Filed: May 10, 2011
    Publication date: May 10, 2012
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Yuji Sakoda, Tomio Onuki
  • Patent number: 8155570
    Abstract: A first bias Vslv is applied to a development roller 22 and a second bias Vmag is applied to a magnetic roller 23 to perform development; after completion of development, without changing the setting of Vslv, of the AC component Vpp2 of Vmag, the peak voltage value Vpp2 (max) at the side with the same polarity as toner is made lower than during a development period and development-residual toner on the development roller 22 is collected to prevent a lateral streak formed on photoconductor drums 1a to 1d during a non-development period.
    Type: Grant
    Filed: March 30, 2009
    Date of Patent: April 10, 2012
    Assignee: Kyocera Mita Corporation
    Inventor: Shoichi Sakata
  • Patent number: 8149432
    Abstract: An information processing apparatus that can be connected to an image-forming apparatus, a method, and a program used for the information processing apparatus are disclosed. The information processing apparatus comprises a control unit for controlling print-setting information set for document data to be printed, a recognition unit for recognizing information about a first function specified by the print-setting information by translating the print-setting information controlled by the control unit, an obtaining unit for obtaining information about a second function of the image-forming apparatus connected to the information processing apparatus, a determination unit for determining whether or not the image-forming apparatus can perform the first function recognized by the recognition unit based on the second-function information obtained by the obtaining unit, and a modification unit for modifying the print-setting information controlled by the control unit based on the determination result.
    Type: Grant
    Filed: October 19, 2010
    Date of Patent: April 3, 2012
    Assignee: Canon Kabushiki Kaisha
    Inventors: Junichiro Kizaki, Satoshi Nishikawa
  • Publication number: 20120070170
    Abstract: A developing device which includes a developing roller which supplies a toner to a photoreceptor and a supply roller which performs supply of a toner to the developing roller and peeling of a toner from the developing roller, and applies a bias voltage to the developing roller so as to develop an electrostatic latent image formed on the photoreceptor with a toner. The developing device includes a first current measuring portion which measures a value of a current flowing in the developing roller, a second current measuring portion which measures a value of a current flowing in the supply roller, and a control portion which calculates a toner charging amount on the developing roller and a toner peeled amount by the supply roller based on measured results by the first current measuring portion and the second current measuring portion.
    Type: Application
    Filed: September 13, 2011
    Publication date: March 22, 2012
    Inventor: Toshimasa HAMADA
  • Patent number: 8139266
    Abstract: The color printing control device outputs color material reduction processed data generated by applying a color material reduction process to each pixel of bitmaps converted to color material colors to be used in printing, when it is judged that the color material reduction printing mode is specified. The color material reduction process includes chroma conversion that reduces chroma and under-color removal/black generation that replaces at least a portion of achromatic components generated by overlaying of a plurality of color materials.
    Type: Grant
    Filed: August 22, 2008
    Date of Patent: March 20, 2012
    Assignee: Konica Minolta Business Technologies, Inc.
    Inventor: Masaru Iida
  • Publication number: 20120063797
    Abstract: An image forming apparatus includes a latent image carrier to carry a latent image, a developing device having a toner carrier with first and second electrodes to develop the latent image by transferring the toner to a developing region between the toner carrier and the latent image carrier while causing the toner to hop between the first and second electrodes and attaching the hopping toner to the latent image, a pulsed power supply to output a first periodic pulse voltage having a mean potential the same as a normal toner charge and a second periodic pulse voltage, a smoothing circuit to make the first periodic pulse voltage smooth to generate a direct voltage, and a toner layer thickness regulator member to regulate, on receiving the direct voltage, a thickness of the toner layer in a region between a toner supply position at which toner is supplied and the developing region.
    Type: Application
    Filed: August 31, 2011
    Publication date: March 15, 2012
    Inventors: Tetsuro HIROTA, Hideki KOSUGI, Masaaki YAMADA, Atsushi KUROKAWA, Hideyasu SEKI, Yasuyuki ISHII
  • Patent number: 8135295
    Abstract: There is provided an image forming apparatus capable of realizing Improvement of an image density by improving dot reproducibility and reducing fog as well. An alternating voltage is applied to a development sleeve so that a first period during which a first peak-to-peak voltage Vpp(1) is applied and a second period during which a second peak-to-peak voltage Vpp(2) that is lower than the first peak-to-peak voltage is applied are repeated alternately. The alternating voltage to be applied is applied so that a development-side potential to move toner from the development sleeve to a photoreceptor and an opposite development-side potential to move toner from the photoreceptor to the development sleeve alternate with each other A frequency of the second period is lower than a frequency of the first period.
    Type: Grant
    Filed: June 22, 2009
    Date of Patent: March 13, 2012
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Toshimasa Hamada
  • Publication number: 20120057891
    Abstract: An image forming apparatus includes a latent image carrier; a latent image writer to write a latent image on the latent image carrier; a developing unit including a toner carrier having first and second electrodes insulated via an insulator member and a voltage applying unit to apply voltages to the first and second electrodes having a potential difference to generate first electric fields to cause the toner to hop from the toner carrier to the latent image carrier to develop a toner image; and a transfer unit to transfer the developed toner image to a transferring member. When alternating voltages having a same phase and same amplitude are applied to the first and second electrodes to form second electric fields between the latent image carrier and the toner carrier, the toner is discharged from the toner carrier to the latent image carrier in a toner discharge mode.
    Type: Application
    Filed: August 23, 2011
    Publication date: March 8, 2012
    Inventors: Yuji ISHIKURA, Yasuyuki Ishii, Hideki Kosugi, Tetsuro Hirota, Masaaki Yamada, Yoshiko Ogawa, Atsushi Kurokawa, Hideyasu Seki, Masanori Horike, Shin Kayahara
  • Patent number: 8131172
    Abstract: 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: Grant
    Filed: March 8, 2010
    Date of Patent: March 6, 2012
    Assignee: Brother Kogyo Kabushiki Kaisha
    Inventors: Masatoshi Shiraki, Hiroshi Handa, Hiroki Mori
  • Patent number: 8126345
    Abstract: An image-forming device can include an image acquiring unit that acquires image data, an image forming unit that forms an image based on the image data, a determining unit that determines whether the image data includes a part having density greater than or equal to a prescribed density, and a controller. The image forming unit can include a developing roller, a supply roller for supplying developer to the developing roller, and a bias applying unit that applies first and second voltages between the developing roller and the supply roller in first and second modes, respectively. The controller can control the bias applying unit to apply one of the first and second voltages when the determining unit determines whether the image data includes the part having density greater than or equal to a prescribed density.
    Type: Grant
    Filed: December 17, 2010
    Date of Patent: February 28, 2012
    Assignee: Brother Kogyo Kabushiki Kaisha
    Inventors: Hiroshi Handa, Hiroki Mori, Masatoshi Shiraki, Yukimasa Yoshida
  • Publication number: 20120045236
    Abstract: An image forming apparatus includes an image bearing member; a developing device for accommodating a transport toner and a carrier; a transferring device for transferring a transparent toner image from the image bearing member onto a surface of a recording material; a heating device for heating the transparent toner image; a switching portion for switching between a first mode in which the transparent toner image is transferred onto the surface of the recording material having a fixed non-transparent toner image and a second mode having an unfixed non-transparent toner image or having no image; and a controller for controlling the developing device so that transfer of the carrier during the first mode is more suppressed than in the second mode.
    Type: Application
    Filed: August 18, 2011
    Publication date: February 23, 2012
    Applicant: CANON KABUSHIKI KAISHA
    Inventor: Asuna Fukamachi
  • Patent number: 8121503
    Abstract: An image forming apparatus includes an image supporting member; a developer supporting member for attaching developer to the image supporting member to form a developer image; a regulation member for forming a thin layer of the developer on the developer supporting member; a charge adjustment member for receiving a charge adjustment voltage and contacting with the thin layer of the developer formed on the developer supporting member to adjust a charge amount of the developer; and a charge adjustment voltage switching unit for switching the charge adjustment voltage applied to the charge adjustment member between an image forming voltage upon forming an image and a non-image forming voltage during a preparation operation.
    Type: Grant
    Filed: January 15, 2009
    Date of Patent: February 21, 2012
    Assignee: Oki Data Corporation
    Inventor: Fumitaka Ozeki
  • Publication number: 20120039620
    Abstract: In a method or system for generation of a toner image layer with a preset layer thickness on a surface of a photoconductor, the two-component mixture of electrically charged toner particles and carrier particles is directed on an auto-surface of a roller adjacent a surface of an applicator element to be inked. At least a portion of the toner particles is transferred onto the surface of the applicator element. An electrical field is generated that exerts at least one force on a portion of the electrically charged toner particles between the roller and the applicator element. A strength of the electrical field is varied to adjust a layer thickness of a layer of the toner particles transferred onto the surface of the applicator element and thus to adjust a thickness of the toner image layer on the photoconductor. A measurement arrangement detects a thickness of at least one region of the toner image layer inked on the surface of the photoconductor as a real value.
    Type: Application
    Filed: May 9, 2005
    Publication date: February 16, 2012
    Inventors: Martin Schleusener, Uwe Höllig
  • Patent number: 8116647
    Abstract: 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: Grant
    Filed: November 16, 2009
    Date of Patent: February 14, 2012
    Assignee: Kyocera Mita Corporation
    Inventors: Kensuke Fujihara, Tamotsu Shimizu, Ryota Maeda, Kouji Fujii, Tomoyuki Kikuta
  • Patent number: 8107840
    Abstract: A supplying roller supplies toner to a developing roller which develops an electrostatic latent image formed on a photoconductive drum. The controller controls a power supply to output a first voltage to the developing roller and a second voltage to the supplying roller. A detector generates a detection signal indicative of the remaining amount of toner. The voltage controller performs voltage correction according to the detection signal either in a first mode or a second mode. In the first mode, the first voltage has a smaller value when the detection signal falls below a reference value than when the detection signal is above the reference value.
    Type: Grant
    Filed: June 24, 2008
    Date of Patent: January 31, 2012
    Assignee: Oki Data Corporation
    Inventor: Yoshio Niijima
  • Publication number: 20120020684
    Abstract: Provided are an image forming apparatus that, when a difference between a developing bias in correcting an image density and a reference developing bias has a value not less than a prescribed value that is set preliminarily, replenishes or consumes a toner forcibly, executes correction of the image density again, and controls the developing bias in such a manner that a toner density is controlled to fall within an appropriate range, and an image forming method using the same. When a difference between a developing bias value after correction of the image density and the reference developing bias becomes larger than the prescribed value to the plus side or the minus side, a toner density control portion performs control to consume or replenish a toner forcibly.
    Type: Application
    Filed: June 29, 2011
    Publication date: January 26, 2012
    Inventors: Hideji SAIKOH, Masayasu NARIMATSU, Kiyofumi MORIMOTO, Kazuma HINOUE