Bias Control Patents (Class 399/55)
  • Publication number: 20110142466
    Abstract: An image forming apparatus includes a sensor that is configured to detect a property of a developer material, a transport unit that is operatively in contact with the developer material and that is configured to move the developer material toward a recording medium, and a controller that receives the property of the developer material from the sensor unit and sets a voltage of the transport unit, wherein the voltage is determined based on the property of the developer material received from the sensor.
    Type: Application
    Filed: December 10, 2009
    Publication date: June 16, 2011
    Applicant: XEROX CORPORATION
    Inventors: W. Bradford WILLARD, Brian Robert CONROW, Kimberly Anne STOLL
  • Patent number: 7957665
    Abstract: The embodiments disclosed herein are directed to methods and devices for a control system to regulate the output voltage of a high voltage power supply (HVPS) in an image forming device. In one embodiment, the HVPS comprises at least two voltage sources connected in series. A print engine controller is configured to disable at least one of the voltage sources when a voltage draw of a load exceeds a maximum differential voltage of the at least two voltage sources.
    Type: Grant
    Filed: August 31, 2007
    Date of Patent: June 7, 2011
    Assignee: Lexmark International, Inc.
    Inventors: Michael Charles Day, William Paul Cook
  • Patent number: 7949271
    Abstract: A development device configured to develop an electrostatic image formed on an image bearing member by applying a developing bias in a development operation includes a developer bearing member configured to bear a developer, a bias applying unit configured to apply an input waveform bias including an alternating component to the developer bearing member, a bias detection unit configured to detect information concerning an output waveform bias generated on the developer bearing member when the bias applying unit applies the input waveform bias to the developer bearing member, and a controller configured to execute a mode for controlling the developing bias to be applied to the developer bearing member based on the input waveform bias and the output waveform bias.
    Type: Grant
    Filed: September 25, 2008
    Date of Patent: May 24, 2011
    Assignee: Canon Kabushiki Kaisha
    Inventor: Shoji Naruge
  • Patent number: 7949270
    Abstract: In an embodiment in which an electrostatic latent image formed on the surface of a photoreceptor is developed with a toner by applying an oscillating bias voltage in which a development-side electrical potential and an opposite development-side electrical potential alternate with each other, between a development sleeve of a development roller and the photoreceptor, the development-side electrical potential is applied in two stages, and, in the two-staged development-side electrical potential, the absolute value of a first electrical potential V1 that is initially applied is larger than the absolute value of a second electrical potential V2 that is subsequently applied.
    Type: Grant
    Filed: December 12, 2007
    Date of Patent: May 24, 2011
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Toshimasa Hamada
  • Patent number: 7941062
    Abstract: An image forming apparatus includes a rotatable photosensitive drum, a charging apparatus to which a charging voltage is applied, an exposure apparatus forming an electrostatic image, a developing apparatus to which a development voltage is applied, a timer measuring an image formation time lapsed from start of rotation of the photosensitive drum and an image formation stop time lapsed from stop of the rotation of the photosensitive drum, and a temperature and humidity sensor detecting a temperature and a humidity of an atmosphere environment around the photosensitive drum. When the humidity is low, a charging voltage is controlled based on a measured result of the timer and detected results of the temperature and humidity sensor. When the humidity is high, the charging voltage is controlled based on the measured result of the timer and the temperature detected result of the temperature and humidity sensor without using humidity information.
    Type: Grant
    Filed: May 27, 2008
    Date of Patent: May 10, 2011
    Assignee: Canon Kabushiki Kaisha
    Inventor: Hideaki Yonekubo
  • Patent number: 7941064
    Abstract: Provided is an image forming apparatus including a charging device for charging a photoreceptor drum, a developing device for developing an electrostatic latent image formed on the photoreceptor drum, a developing bias applying device for applying a developing bias voltage to the developing device, a toner image density sensor for detecting an image density of a toner image formed on the photoreceptor drum, and a control portion for controlling an output value of the developing bias applying device, in which the control portion adjusts the developing bias voltage based on an average print coverage of document in previous printing jobs.
    Type: Grant
    Filed: January 23, 2009
    Date of Patent: May 10, 2011
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Shuhichi Morikuni, Shoji Tomita
  • Patent number: 7941080
    Abstract: An image forming apparatus is provided with a photoconductive member on which a latent image is to be formed, a developing roller for developing the latent image formed on the photoconductive member by a first bias, and a magnetic roller for forming a magnetic brush thereon with a two-component developer and forming a thin toner layer on the developing roller by a second bias. If (D1) denotes the duty ratio of a first alternating-current bias included in the first bias and (D2) denotes the duty ratio of a second alternating-current bias included in the second bias, the duty ratios (D1, D2) satisfy the following relationship: D1>100?D2.
    Type: Grant
    Filed: March 18, 2008
    Date of Patent: May 10, 2011
    Assignee: Kyocera Mita Corporation
    Inventors: Shoichi Sakata, Takahisa Nakaue, Kiyotaka Kobayashi, Yukihiro Mori
  • Patent number: 7937030
    Abstract: An aspect of the invention provides a developing unit that includes: a developer; an image carrier on which an electrostatic latent image is formed; a first developer carrier configured to develop the electrostatic latent image formed on the image carrier by causing the developer to adhere to the electrostatic latent image; a first restriction member configured to be in press-contact with the first developer carrier; a second developer carrier configured to abut to the first developer carrier, and to form a developer layer on the second developer carrier; a second restriction member configured to abut to the second developer carrier; and a supplying member configured to supply the second developer carrier with the developer.
    Type: Grant
    Filed: May 22, 2009
    Date of Patent: May 3, 2011
    Assignee: Oki Data Corporation
    Inventor: Hayato Matsumoto
  • Patent number: 7937009
    Abstract: An image forming apparatus includes a photoconductive medium electrified by an electrifying apparatus to a predetermined electric potential, a plurality of color developing apparatuses which are fixed around the photoconductive medium, each color developing apparatus having a developing roller to adhere a predetermined color toner to an electrostatic latent image formed on the photoconductive medium by a laser scanning unit, and a supplying roller to supply a toner to the developing roller, a voltage supplying apparatus to apply a predetermined bias voltage to the developing roller and the supplying roller, and a controlling apparatus to control a degree and a timing of applying the bias voltages to the developing roller and the supplying roller to control a movement state of the toner between the supplying roller and the developing roller.
    Type: Grant
    Filed: May 7, 2009
    Date of Patent: May 3, 2011
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Myung-ho Kyung
  • Patent number: 7937008
    Abstract: An image forming apparatus having a touchdown-development type developing apparatus, in which a toner collecting roller that collects scattered toner suspended in the vicinity of a toner holding body and a two-component developer holding body is arranged on the downstream side in a rotational direction of the two-component developer holding body from a closest position of the two-component developer holding body and the toner holding body, and between the two-component developer holding body and the housing wall, and further, bias means that applies a bias voltage for collecting the scattered toner to the toner collecting roller, and image density sensing means for sensing a density of a toner image developed on the electrostatic latent image holding body surface or a toner image on a transfer body onto which the toner image developed on the electrostatic latent image holding body surface is transferred to control the bias voltage are provided.
    Type: Grant
    Filed: February 12, 2008
    Date of Patent: May 3, 2011
    Assignee: Kyocera Mita Corporation
    Inventors: Masashi Fujishima, Akihiro Watanabe, Sayo Uemura, Yukihiro Mori
  • Publication number: 20110097097
    Abstract: An image forming apparatus is disclosed. Zener diode separately installed to correspond to each developing device so as to form a difference in potential between the developing bias voltage and the supply bias voltage of each developing device, is installed at a common end, so that a deviation of the developing voltage applied to the developing device affected by a deviation of Zener diode components can be reduced, resulting in an increased color image quality. In addition, the Zener diode is installed in a common end, such that the number of Zener diodes is reduced, resulting in a reduction in production costs.
    Type: Application
    Filed: October 25, 2010
    Publication date: April 28, 2011
    Applicant: SAMSUNG ELECTRONICS CO., LTD.
    Inventor: Yoon Seop Eom
  • Patent number: 7929889
    Abstract: Provided is an image forming apparatus including: a latent image carrier; a charging unit; a latent image forming unit; a developing unit that has a toner carrier; a transferring unit that transfers the toner image on the transfer medium; and a cleaning unit that removes a toner that remains to be adhered to the latent image carrier, wherein the toner carrier carries a toner layer including a contact toner that is directly in contact with the surface of the toner carrier and a non-contact toner that is not directly in contact with the surface of the toner carrier on the surface thereof, and wherein a voltage of the transferring bias is a DC voltage that does not generate discharge between the image portion of the latent image carrier and the transfer medium but generate discharge between the non-image portion of the latent image carrier and the transfer medium.
    Type: Grant
    Filed: November 19, 2009
    Date of Patent: April 19, 2011
    Assignee: Seiko Epson Corporation
    Inventors: Yoichi Yamada, Atsunori Kitazawa
  • Publication number: 20110085810
    Abstract: According to a method and apparatus for controlling a voltage of an image forming apparatus, a transferring roll resistance, which indicates the resistance between a transferring roller and a photoconductor drum, is detected by applying a first voltage to the transferring roller. A transferring voltage, which corresponds to the detected transferring roll resistance, is applied to the transferring roller with reference to a transferring table which corresponds to the paper resistance, and a transferring is performed on a printing paper by using a transferring roller to which a transferring voltage is applied.
    Type: Application
    Filed: August 17, 2010
    Publication date: April 14, 2011
    Applicant: SAMSUNG ELECTRONICS CO., LTD.
    Inventor: Jeong-Jai Choi
  • Publication number: 20110085811
    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: Application
    Filed: December 17, 2010
    Publication date: April 14, 2011
    Applicant: BROTHER KOGYO KABUSHIKI KAISHA
    Inventors: Hiroshi HANDA, Hiroki MORI, Masatoshi SHIRAKI, Yukimasa YOSHIDA
  • Patent number: 7920801
    Abstract: Related is an image forming apparatus by electrophotography having a function of performing adjustment of image quality when performing image formation. The image forming apparatus includes a detection portion for detecting a fixing temperature of a fixing apparatus; a storage portion for storing an application history of a development bias; a count portion for counting a reposed time from a point when an operation of image formation is ended; a determination portion for determining a change range of the development bias immediately before the end of the operation of image formation; and an execution portion for executing adjustment of image quality by setting the development bias based on a determination result from the determination portion when the reposed time or the fixing temperature exceeds a predetermined value.
    Type: Grant
    Filed: April 8, 2009
    Date of Patent: April 5, 2011
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Masayuki Otsuka, Katsuhiro Nagayama, Takashi Kitagawa
  • Patent number: 7917046
    Abstract: The first direct-current bias power supply applying the first direct-current bias Vdc1 and the first alternating-current bias power supply applying the first alternating-current bias Vac1 are connected to a development roller. The second direct-current bias power supply applying the second direct-current bias Vdc2 and the second alternating-current bias power supply applying the second alternating-current bias Vac2 are connected to a magnetic roller. The peak-to-peak value Vpp of the first alternating-current bias Vac1 applied to the development roller remains the same, and the second alternating-current bias Vac2 that is in phase with the first alternating-current bias Vac1 and that has a peak-to-peak value of a predetermined value or above is applied to the magnetic roller. Thus, the potential difference between the peak voltage of the development bias on the opposite polarity side to the polarity of the toner and the peak voltage of a supply bias is set at a predetermined value or below.
    Type: Grant
    Filed: June 20, 2008
    Date of Patent: March 29, 2011
    Assignee: Kyocera Mita Corporation
    Inventor: Norio Kubo
  • Patent number: 7912389
    Abstract: An image forming apparatus, wherein the following formulae are satisfied: 0.22 ? ( M / S ) L ? 0.4 , ? ( Q M ) L = Vc ( Lt 2 ? ? 0 ? ? t + Ld ? 0 ? ? d ) × ( M S ) L ( Dt ? ? max - Dt 0.1 ) { ? × ( M S ) L - 0.1 } ? ( Lt 2 ? ? 0 ? ? t + Ld ? 0 ? ? d ) × ( M S ) L 500 ? ?? ? ( Dt ? ? max - Dt 0.1 ) { ? × ( M S ) L - 0.1 } ? ( Lt 2 ? ? 0 ? ? t + Ld ? 0 ? ? d ) × ( M S ) L 150 ?? ? ( Dt ? ? max - Dt 0.1 ) { ? × ( M S ) L - 0.
    Type: Grant
    Filed: January 30, 2008
    Date of Patent: March 22, 2011
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takeshi Yamamoto, Manami Haraguchi, Kenta Kubo, Yoshinobu Baba, Koh Ishigami
  • Publication number: 20110064429
    Abstract: According to one embodiment, an image forming apparatus includes a developing unit configured to store a developer includes a toner and a carrier and to form a developer image, a toner attachment amount detection portion configured to detect an attachment amount of a toner formed on a photoconductor or an intermediate transfer body, a developing bias voltage change portion configured to change a plurality of developing bias voltages including a developing contrast voltage in a manner that the detected attachment amount of the toner becomes a value in a predetermined range, a carrier supply time correction portion configured to correct a carrier supply time in response to the value of the changed developing contrast voltage, and a carrier supply portion configured to supply a carrier in a corrected carrier supply time at a predetermined timing.
    Type: Application
    Filed: August 30, 2010
    Publication date: March 17, 2011
    Applicants: KABUSHIKI KAISHA TOSHIBA, TOSHIBA TEC KABUSHIKI KAISHA
    Inventors: Takao Izumi, Hiroshi Murata, Takashi Hatakeyama
  • Publication number: 20110064432
    Abstract: A disclosed developing device includes a toner carrying member having electrodes, a toner supply unit supplying the toner to the toner carrying member, and a hopping electric field generator unit generating electric field to cause the toner hopping on the toner carrying member by applying a pulse voltage to the electrodes. The hopping electric field generator unit includes a pulse voltage generator circuit generating the pulse voltage, a first direct-current power source supplying bias to the pulse voltage generator circuit for regulating a peak value of the pulse voltage, and a second direct-current power source having a same polarity with a toner charging polarity, and outputting a variable voltage level. The hopping electric field generator unit controls the peak value of the pulse voltage by changing an output of the first power source and a mean thereof by changing an output of the second power source.
    Type: Application
    Filed: September 10, 2010
    Publication date: March 17, 2011
    Inventors: Masanori Horike, Tetsuro Hirota, Atsushi Kurokawa, Hideki Kosugi, Masaaki Yamada, Yoshiko Ogawa, Yuji Ishikura
  • Patent number: 7907856
    Abstract: An apparatus for developing a latent image on a latent image carrier includes a toner carrier and multiple electrodes arranged at intervals on a surface of the toner carrier. A potential difference is formed between even-numbered electrodes and odd-numbered electrodes of the electrodes by applying a first pulse voltage to the even-numbered electrodes and a second pulse voltage to the odd-numbered electrodes so that toner on the surface of the toner carrier moves back and forth between the electrodes, where the first and second pulse voltages are in different phases, and the toner moving back and forth between the electrodes is conveyed to a position facing the latent image carrier by movement of the surface of the toner carrier and thereby caused to adhere to the latent image on the latent image carrier.
    Type: Grant
    Filed: October 12, 2006
    Date of Patent: March 15, 2011
    Assignee: Ricoh Company, Ltd.
    Inventors: Takeo Tsukamoto, Nobuaki Kondoh, Masanori Horike, Tomoko Takahashi, Masaaki Yamada, Hideki Kosugi, Ichiro Kadota, Yoshinori Nakagawa, Yasuyuki Ishii
  • Patent number: 7907855
    Abstract: An image forming apparatus including a first developing device including a first developer carrying member for carrying a developer containing toner, wherein a developing voltage including an AC component is applicable to the first developer carrying member to develop an electrostatic image; a second developing device including a second developer carrying member for carrying a developer containing toner, wherein a developing voltage including an AC component is applicable to the second developer carrying member to develop an electrostatic image; a transferring device for transferring a toner image formed by the first developing device to a moving transfer medium and then transferring a toner image formed by the second developing device onto the transfer medium; a controller for selectively executing an operation in a first mode wherein the image is formed by both of the first developing device and the second developing device or in a second mode wherein the image is formed by only the second developing device
    Type: Grant
    Filed: February 13, 2008
    Date of Patent: March 15, 2011
    Assignee: Canon Kabushiki Kaisha
    Inventor: Masanori Akita
  • Publication number: 20110058836
    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: Application
    Filed: September 7, 2010
    Publication date: March 10, 2011
    Applicant: KONICA MINOLTA BUSINESS TECHNOLOGIES, INC.
    Inventors: Tomoyuki IMURA, Kazuhiro Saito, Takuya Okada, Takuya Sasaki, Chikara Tsutsui, Takayuki Takai
  • Publication number: 20110058833
    Abstract: An image forming apparatus includes: a charging unit which charges a surface of an image bearing member by contacting the image bearing member with a charging member to which a charging bias is applied, the charging bias being a voltage obtained by superimposing an AC voltage on a DC voltage; an electrostatic latent image forming unit which forms an electrostatic latent image on the surface of the image bearing member which is charged by the charging unit; a developing unit which develops the electrostatic latent image by using a developing bias formed by the voltage obtained by superimposing the AC voltage on the DC voltage; and a control unit which performs changing control of an AC frequency of the charging bias while maintaining a frequency ratio of an AC frequency of the developing bias to be an integral multiple of the AC frequency of the charging bias.
    Type: Application
    Filed: August 24, 2010
    Publication date: March 10, 2011
    Applicant: CANON KABUSHIKI KAISHA
    Inventor: Tetsuhiro Yoshimoto
  • Publication number: 20110058835
    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: Application
    Filed: September 7, 2010
    Publication date: March 10, 2011
    Applicant: KONICA MINOLTA BUSINESS TECHNOLOGIES, INC.
    Inventors: Tomoyuki IMURA, Kazuhiro Saito, Takuya Okada, Takuya Sasaki, Chikara Tsutsui, Takayuki Takai
  • Patent number: 7903989
    Abstract: A developing apparatus includes a developer carrying member rotatably provided for carrying a developer; a regulating member that has conductivity, and is provided to be capable of being in contact with the developer carrying member for regulating a amount of the developer carried by the developer carrying member; a power supply that applies voltage to the regulating member; a deformation detecting unit that detects information relating to the deformation of the developer carrying member; and a control unit that controls the power supply to apply a correction voltage when a deformed portion of the developer carrying member passes through the regulating member in order that the amount of the developer carried by the developer carrying member in the circumferential direction is in uniform based on a result of the detection by the deformation detecting unit.
    Type: Grant
    Filed: March 30, 2009
    Date of Patent: March 8, 2011
    Assignee: Canon Kabushiki Kaisha
    Inventor: Takayuki Tanaka
  • Patent number: 7904008
    Abstract: The present invention is directed to a non-contact, single-component developing system for electrophotographic devices that enables high speed, high quality development and color development without an accumulator, or some other intermediate transfer member by employing a plurality of ancillary developing members operating in tandem with a toner-carrying member to facilitate toner detachment from the toner-carrying member. The developing system of the present invention utilizes high electrostatic forces to enable toner jump without AC voltages and exploits toner adhesion forces adhering toner particles to a surface (e.g., a latent image-bearing member) to facilitate high speed development.
    Type: Grant
    Filed: November 3, 2008
    Date of Patent: March 8, 2011
    Inventor: Jang Yi
  • Publication number: 20110052230
    Abstract: An embodiment of an image forming apparatus may include a photosensitive member, a development unit, a transfer member, a sensor, and a correcting unit. The development unit may form a toner image on the photosensitive member. The toner image member may be transferred onto the transfer member. The sensor may detect light from a surface of the transfer member. The correcting unit may correct a toner density in a first area of the transfer member after transfer of a toner image of a test pattern to the first area. The correcting unit may correct the toner density on the basis of a difference between an output value of the sensor from a second area before the transfer of the toner image of the test pattern and an output value of the sensor from the second area after the transfer of the toner image of the test pattern.
    Type: Application
    Filed: August 6, 2010
    Publication date: March 3, 2011
    Applicant: KYOCERA MITA CORPORATION
    Inventor: Keisuke Isoda
  • Patent number: 7899348
    Abstract: A controller takes in a detection signal indicating the surface electrical potential of a photoconductive drum (7) from a surface electrical potential sensor (step #1), and determines whether the surface electrical potential is smaller than the predetermined threshold value (step #2). As a result, when the controller (6) determines that the surface electrical potential is equal to or greater than the predetermined threshold value (NO in step #2), it uses the low print rate density patch to execute the density adjustments in accordance with the toner density and the developing bias associated with the density patch (step #3). When the controller (6) determines that the surface electrical potential is smaller than the predetermined threshold value (NO in step #1), it uses a high print rate density patch to execute the density adjustments in accordance with the toner density and the developing bias associated with the density patch (step #4).
    Type: Grant
    Filed: December 27, 2007
    Date of Patent: March 1, 2011
    Assignee: Kyocera Mita Corporation
    Inventors: Yoshihiko Maruyama, Keisuke Isoda
  • Publication number: 20110044705
    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: Application
    Filed: July 23, 2010
    Publication date: February 24, 2011
    Applicant: Konica Minolta Business Technologies
    Inventors: Hironori AKASHI, Soh Hirota, Mitsuru Obara, Takashi Harashima, Kanako Kibihara
  • Patent number: 7890029
    Abstract: There is provided an image forming apparatus capable of realizing improvement of an image density by improving dot reproducibility and reducing fog at the same time. 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. The potential to be finally applied in the first period is preferably the development-side potential.
    Type: Grant
    Filed: June 10, 2009
    Date of Patent: February 15, 2011
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Toshimasa Hamada
  • Patent number: 7890005
    Abstract: A method, system, and manufacture for adjusting electrostatic charges in a laser printer. A charge is applied to a photoconductor drum surface to create a dark voltage. An image area of the photoconductor drum is exposed with a printhead using a defined energy level to discharge the charge from the image area. An exposure voltage of the photoconductor drum is measured after the image area has been exposed. A first optimization is performed to determine an adjusted dark voltage and an adjusted energy level based on the measured exposure voltage and the dark voltage and the energy levels applied to the photoconductor drum. An applicator voltage is applied to an applicator that applies toner to the exposed image area of the photoconductor drum. Toner density applied to the photoconductor drum is measured and a second optimization is performed to adjust the applicator voltage to produce a target toner density.
    Type: Grant
    Filed: January 7, 2009
    Date of Patent: February 15, 2011
    Assignee: Infoprint Solutions Company, LLC
    Inventors: Timothy Graham Bradley, Larry M. Ernst
  • Publication number: 20110033196
    Abstract: An image forming apparatus with a correction function for correcting density of an image, including: an image bearing member configured to convey the image in a first direction; and a controller configured to perform a bias correction and a ? correction for the density, wherein the controller includes: a test patch generator configured to generate on the image bearing member a test patch including a first test patch and a second test patch; a first density sensor configured to detect density of the first test patch; a second density sensor configured to detect density of the second test patch; a selector configured to select one of a first detection signal from the first density sensor and a second detection signal from the second density sensor as a bias-correction detection signal and another detection signal as a ?-correction detection signal.
    Type: Application
    Filed: August 2, 2010
    Publication date: February 10, 2011
    Applicant: KYOCERA MITA CORPORATION
    Inventor: Nobuyuki Fuchimoto
  • Patent number: 7885564
    Abstract: An image-forming device includes an image acquiring unit, an image forming unit, a determining unit, and a controller. The image acquiring unit acquires image data for one page. The image forming unit forms an image based on the image data. The image forming unit includes a developing roller, a supply roller, and a bias applying unit. The developing roller carries a developer. The supply roller supplies the developer to the developing roller. The bias applying unit applies a first voltage between the developing roller and the supply roller in a first mode, and applies a second voltage between the developing roller and the supply roller in a second mode. The determining unit determines whether the image data includes a part having density greater than or equal to a prescribed density.
    Type: Grant
    Filed: February 23, 2009
    Date of Patent: February 8, 2011
    Assignee: Brother Kogyo Kabushiki Kaisha
    Inventors: Hiroshi Handa, Hiroki Mori, Masatoshi Shiraki, Yukimasa Yoshida
  • Patent number: 7885563
    Abstract: A development apparatus is provided that can quickly form high quality printing material by steadily supplying developer charged and thinned to a uniform thickness and can also prevent the decrease in the quality of the printing material in a case where the developer carrier and developer supply unit are operated quickly. The toner supply roller is constructed in a manner using the elastic material with a hardness of HAF [degree] set to 20?HAF?80 measured by an Asker F-type and disposed in a manner such that the amount of push ?, defined as the amount pushed by the contact between the developer supply unit and the developer carrier, is 0.5 [mm] or below. In addition, toner supply bias voltage VS [V] applied to the toner supply roller has a frequency f [Hz] of 500?f?5000, and, with VSH and VSL as the peak values of the AC voltage component, fulfill the condition of 1?|VSH?VD|/|VD?VSL?5.
    Type: Grant
    Filed: August 29, 2006
    Date of Patent: February 8, 2011
    Assignee: Oki Data Corporation
    Inventor: Akihiro Yamamura
  • Publication number: 20110026957
    Abstract: An image forming apparatus includes an image carrier, a charging device to be applied with a charging voltage, an exposure device, a developer carrier to be applied with a development voltage, a developer supplying member to be applied with a supply voltage, a developer regulation member to be applied with a regulation voltage, and a voltage controller. The developer carrier has thereon a developer having a charge amount Q/M. The charge amount Q/M satisfies 25 [?C/g]?|Q/M|?40 [?C/g]. The image carrier has a surface potential Vopc, the development voltage is expressed as Vdb, and the developer carrier has a developer layer potential Vtnr thereon. The developer layer potential Vtnr relative to a difference between the surface potential Vopc and the development voltage Vdb is expressed by a ratio ?. The ratio ? satisfies 0.1???0.2.
    Type: Application
    Filed: July 13, 2010
    Publication date: February 3, 2011
    Applicant: Oki Data Corporation
    Inventor: Fumitaka OZEKI
  • Publication number: 20110026955
    Abstract: An image forming apparatus comprising a photosensitive body, a charger configured to charge the photosensitive body, an exposure unit configured to expose the photosensitive body charged by the charger, a developer transport section configured to cause relative movement with respect to the photosensitive body for transporting developer therebetween, a current measurement section configured to measure a current flowing between the photosensitive body and the developer transport section, and a determination unit configured to compare a current with a threshold, the current measured by the current measurement section when the photosensitive body and the developer transport section move relatively to each other and a first area of the photosensitive body that needs to be exposed faces the developer transport section, and determine whether an exposure of the photosensitive body is proper based on a result of the comparison.
    Type: Application
    Filed: July 26, 2010
    Publication date: February 3, 2011
    Applicant: BROTHER KOGYO KABUSHIKI KAISHA
    Inventors: Masamitsu TAKAHASHI, Hiroyuki NAGANAWA
  • Patent number: 7877030
    Abstract: An image forming apparatus includes a developer carrying member to which a developing bias is applied. A frequency f of a developing bias waveform, a developing area S1 which is a time-integrated value of a difference between a voltage value of the developing bias and a solid electrostatic image potential VL in a developing period of the developing bias, a collecting area S2 which is a time-integrated value of a difference between the voltage value of the developing bias and VL in a collecting period of the developing bias, and a developing contrast value Vcon are used for defining a range of a value of the developing bias frequency f, a range of a value of a voltage change rate ? at VL during transition of the developing bias voltage value from a developing-side voltage to a collecting-side voltage, and a range of a value represented by the formula: {(S1?1.28×S2)×f/Vcon}×exp(?2.0×10?5×f/Hz).
    Type: Grant
    Filed: August 5, 2009
    Date of Patent: January 25, 2011
    Assignee: Canon Kabushiki Kaisha
    Inventors: Juun Horie, Takeshi Yamamoto, Manami Haraguchi, Kenta Kubo, Tomoaki Miyazawa, Hirokazu Usami
  • Patent number: 7869721
    Abstract: A method (400) and apparatus (100) that detects carrier particles (130) in an electrophotographic device is disclosed. The apparatus may include an image carrying member (110). The image carrying member may have a first side (111) and have a second side (112) opposite from the first side. The image carrying member may be configured to operate in a direction of motion (115). The image carrying member may also be configured to transport an image on the first side. The apparatus may also include a magnet (120) coupled to the second side of the image carrying member. The magnet may have a length (122). The length of the magnet may be at an angle (124) of greater than zero and less than 90 degrees to the direction of motion of the image carrying member. The magnet may be configured to attract toner carrier particles transported on the image carrying member. The apparatus may also include a first sensor (140) coupled in proximity to the first side of the image carrying member and coupled in proximity to the magnet.
    Type: Grant
    Filed: July 7, 2008
    Date of Patent: January 11, 2011
    Assignee: Xerox Corporation
    Inventors: Michael D. Thompson, Paul W. Morehouse, Jr., Diane Foley
  • Patent number: 7869727
    Abstract: High quality images are provided by controlling development conditions based on the proportion of the toner layer potential difference, which a difference between the toner layer potential and electrostatic latent image potential, to the development contrast potential difference, which is a difference between the development bias potential and electrostatic latent image potential. The control section for controlling a development power supply controls the voltage supplied by the development power supply, based on the toner layer potential difference and development contrast potential difference in the development section. This arrangement ensures formation of high-quality images free from concentration of toner.
    Type: Grant
    Filed: February 12, 2009
    Date of Patent: January 11, 2011
    Assignee: Konica Minolta Business Technologies, Inc.
    Inventors: Kazutoshi Kobayashi, Yutaka Miyasaka, Nobuyasu Tamura
  • Patent number: 7869726
    Abstract: An image forming apparatus performs prints image data. A dividing section divides the image data of a print job into a plurality of sub data areas m(i) (i=1 to n). A duty computing section computes a print duty for each of the plurality of sub data areas (m(1)-m(n)) based on the number of printed dots in the print job and a total number of printable dots in a printable area. A first power supply applies a first voltage to a developing roller. A second power supply applies a second voltage to the developer supplying roller. The voltage difference between the first and second voltages is determined in accordance with the print duty.
    Type: Grant
    Filed: January 28, 2008
    Date of Patent: January 11, 2011
    Assignee: Oki Data Corporation
    Inventor: Toshiharu Sato
  • Patent number: 7865099
    Abstract: There is described an image forming apparatus, which makes it possible to suppress quality degradation of an image on the basis of a developing electric current profile without optically detecting density of a patch image. The image forming apparatus includes: a developing current detecting sensor to detect a developing current; and a control section that conducts consecutive operations of: creating a detecting-use image pattern for detecting a developing characteristic, by aligning a plurality of image patterns, which are different from each other in density; forming a latent image of the detecting-use image pattern onto the photoreceptor element; finding a developing electric current profile, which represents a transition of the developing electric current flowing during an operation of developing the detecting-use image pattern, from an outputted signal of the developing current; and changing an image forming condition, based on the developing electric current profile found by the finding operation.
    Type: Grant
    Filed: January 16, 2008
    Date of Patent: January 4, 2011
    Assignee: Konica Minolta Business Technologies, Inc.
    Inventors: Kazutoshi Kobayashi, Yutaka Miyasaka, Nobuyasu Tamura
  • Publication number: 20100329709
    Abstract: An image forming apparatus includes an image carrier; a charging device that charges a surface of the image carrier; an exposure device that forms an electrostatic latent image on the charged surface of the image carrier; a developing device that forms a toner image by transferring toner to the electrostatic latent image from a developing member opposed to the image carrier; and a transfer device that either directly transfers the toner image onto a recording medium or transfers the toner image onto a recording medium after the toner image is temporarily transferred onto an intermediate transfer member.
    Type: Application
    Filed: November 13, 2009
    Publication date: December 30, 2010
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Takashi OCHI, Shinichi KURAMOTO, Shinichiro FUJIMORI
  • Publication number: 20100322649
    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: Application
    Filed: June 8, 2010
    Publication date: December 23, 2010
    Applicant: Oki Data Corporation
    Inventor: Hidetaka Mitsunobu
  • Publication number: 20100322647
    Abstract: A color electrophotographic image forming apparatus, wherein a plurality of each including an electrophotographic photosensitive drum are detachably mountable to a main assembly of the apparatus, the apparatus includes an exposure device for forming an electrostatic latent image on the drum; a cartridge supporting member capable of demountably supporting the cartridges and movable between an inside position and an outside position; a driving device for driving the drum; an intermediary transfer belt onto which an image provided by developing the electrostatic latent image formed on the drum is transferred; and a controller for controlling execution of image formation in response to print jobs received by the apparatus, wherein the controller causes the exposure device to expose the drum to light after completion of a last one of the print jobs, and the controller stops drive of the by the driving device in a state that the exposed area is opposed to the intermediary transfer belt.
    Type: Application
    Filed: June 17, 2010
    Publication date: December 23, 2010
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Kazuhiro Hosohara, Toshiyuki Watanabe
  • Patent number: 7856188
    Abstract: A developing method in an image-forming device is provided. The developing method includes the steps of charging a photoreceptor; exposing the photoreceptor to form a first latent image on the photoreceptor; developing the first latent image by a first developing unit having a first potential to form a first toner image; and discharging the photoreceptor having the first toner image, such that when the photoreceptor is charged again, the first toner image on the photoreceptor has a second potential, and the second potential is approximately the same as the first potential of the first developing unit.
    Type: Grant
    Filed: February 12, 2008
    Date of Patent: December 21, 2010
    Assignee: Aetas Technology, Incorporated
    Inventors: Eric Chun-Wei Shih, Dianne Tan-Feng Tsai
  • Publication number: 20100316402
    Abstract: A developing device includes a developer bearing member for bearing a developer so as to develop an electrostatic image, a restricting member for restricting the amount of developer born on the developer bearing member, a detector for detecting information on the amount of developer existing between the developer bearing member and the restricting member, and a controller which can change a value of a voltage to be applied to the restricting member during image formation based on a result detected by the detector.
    Type: Application
    Filed: June 7, 2010
    Publication date: December 16, 2010
    Applicant: CANON KABUSHIKI KAISHA
    Inventor: Hiroyuki Oba
  • Patent number: 7853161
    Abstract: A potential difference between the photoreceptor and the development roller is set at a value at which the normally charged toner on the development roller can be flown toward the photoreceptor in the development phase at the time of compulsorily consuming the toner, and this potential difference is set at a value at which the flown normally charged toner can be returned to the development roller in the recovery phase.
    Type: Grant
    Filed: December 11, 2008
    Date of Patent: December 14, 2010
    Assignee: Konica Minolta Business Technologies, Inc.
    Inventors: Toru Hayase, Kuniya Matsuura, Yuusuke Okuno, Kentaro Katori, Hiromasa Ueno, Hideaki Hayashi
  • Patent number: 7848670
    Abstract: A developing device includes an image carrier, a developer carrier, a biasing unit disposed upstream of a developing area, and a controller configured to control the biasing unit, and a cleaning member disposed downstream of the developing area to remove the liquid developing agent remaining on the developer carrier. A latent image held on the image carrier may be developed with the liquid developing agent, including charged toner and a carrier liquid, at the developing area where the developer carrier faces the image carrier. The controller causes the biasing unit to apply a first bias voltage to the surface of the liquid developing agent held on the developer carrier during developing, or a second bias voltage thereto during cleaning.
    Type: Grant
    Filed: August 17, 2007
    Date of Patent: December 7, 2010
    Assignee: Brother Kogyo Kabushiki Kaisha
    Inventor: Keisuke Takahashi
  • Patent number: 7848691
    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: February 4, 2008
    Date of Patent: December 7, 2010
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Je-hwan You, Gyeong-ho Park
  • Publication number: 20100303488
    Abstract: An image forming apparatus includes a rotatable image bearing member; a developing device, including a developer carrying member and developing bias application means for applying a developing bias for developing a developer image; a rotatable intermediary transfer member; a primary transfer member for forming a primary transfer nip and for transferring the developer image from the image bearing member onto the intermediary transfer member; a secondary transfer member for secondary-transferring the developer image from the intermediary transfer member onto a recording material; wherein an area of the image bearing member includes a first area at least containing an area located in primary transfer nip at a time when a speed of the intermediary transfer member is temporarily decreased and includes a second area located in the primary transfer nip when there is no temporary change in speed; and a control device for controlling a developing bias.
    Type: Application
    Filed: May 25, 2010
    Publication date: December 2, 2010
    Applicant: CANON KABUSHIKI KAISHA
    Inventor: Yuya Yanagi