Control Of Charging Patents (Class 399/50)
  • Patent number: 10708464
    Abstract: An image forming apparatus includes a connecting device to which a charging apparatus is connected, an image forming device, an operating device, and a control device. The control device functions as an operation accepter, a controller, a charging processor, and a notifier. The notifier performs a processing for giving a first notice; the first notice is for asking a user whether or not to donate all of or part of a remaining money which is remaining, posterior to charging for a print job, in an inserted amount of money. After the notifier has performed the processing for giving the first notice, when the operation accepter accepts an instruction of execution of the donation, the charging processor performs a charging processing by subtracting, from the inserted amount of money, a charging amount for the print job and an amount of donation indicated by the instruction of execution of the donation.
    Type: Grant
    Filed: August 23, 2019
    Date of Patent: July 7, 2020
    Assignee: KYOCERA Document Solutions Inc.
    Inventor: Naoya Miyaji
  • Patent number: 10698332
    Abstract: An image forming apparatus includes a photosensitive member, a first charging roller, a first cleaning member, a second charging roller, and a second cleaning member. The following relationship is satisfied: (X×L0+L1+L2)?(Y×L3+L4)?0 where L0 represents a length of a whole circumference of the first charging roller, L1 represents a length between a first contact area and a first contact position of the first charging roller and the photosensitive member, L3 represents a length of a whole circumference of the second charging roller, L4 represents a length between a second contact area and a second contact position, L2 represents a length between the first contact position and the second contact position, X represents an integer in a range of 0?X?40, and Y represents an integer in a range of 0?Y?40.
    Type: Grant
    Filed: August 9, 2019
    Date of Patent: June 30, 2020
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tadashi Fukuda, Takahito Fuse, Masami Hano, Shota Soda
  • Patent number: 10698339
    Abstract: A color imaging device includes a plurality of developer rolls with a common operating point, such as a common operating voltage. To determine the operating point, an acceptable range of color density is determined for each toner, the range being lighter and darker than an optimum color density for that toner. A search range is devised such that values within the range are examined relative to deviations from the optimum color density per each toner. The common operating point is selected as that having the lowest deviation per all toners. Also, if the common operating point corresponds to a color density darker than the acceptable range of color density for any toner, additional halftoning occurs compared to traditional halftoning, such as for continuous tones or solids. In this way, four color developer rolls can be operated from a single power supply, yet still provide acceptable color images.
    Type: Grant
    Filed: May 28, 2019
    Date of Patent: June 30, 2020
    Assignee: LEXMARK INTERNATIONAL, INC.
    Inventors: Marc Cousoulis, Gary Scott Overall
  • Patent number: 10663879
    Abstract: In an image forming apparatus, a charging process of a photosensitive member is performed by forming a combined surface potential Vd(U+L) by superimposing, on a first charge potential Vd(U) formed on a surface of the photosensitive member by a first corona charger, a second charge potential Vd(L) provided by a second corona charger. The apparatus includes a controller for executing an adjusting operation in which a superimposition start voltage Vg(L)A, which is the second voltage Vg(L) at which formation of the combined surface potential Vd(U+L) is started, is acquired by changing the second voltage Vg(L) applied to a grid electrode of the second corona charger in a state that the first charge potential Vd(U) is formed on the surface of the photosensitive member and in which setting of the second voltage Vg(L) during the charging process is adjusted on the basis of the superimposition start voltage Vg(L).
    Type: Grant
    Filed: February 7, 2019
    Date of Patent: May 26, 2020
    Assignee: Canon Kabushiki Kaisha
    Inventor: Kenichiro Kitajima
  • Patent number: 10663891
    Abstract: A color imaging device includes a plurality of developer rolls with a common operating point, such as a common operating voltage. To determine the operating point, an acceptable range of color density is determined for each toner, the range being lighter and darker than an optimum color density for that toner. A search range is devised such that values within the range are examined relative to deviations from the optimum color density per each toner. The common operating point is selected as that having the lowest deviation per all toners. Also, if the common operating point corresponds to a color density darker than the acceptable range of color density for any toner, additional halftoning occurs compared to traditional halftoning, such as for continuous tones or solids. In this way, four color developer rolls can be operated from a single power supply, yet still provide acceptable color images.
    Type: Grant
    Filed: May 28, 2019
    Date of Patent: May 26, 2020
    Assignee: LEXMARK INTERNATIONAL, INC.
    Inventors: Marc Cousoulis, Gary Scott Overall
  • Patent number: 10627736
    Abstract: An image forming apparatus includes an image bearer, a charger, and a power source to apply to the charger a charging bias obtained by superimposing an AC voltage on a DC voltage. The power source includes a peak detection circuit to detect positive and negative peak values of a voltage of an AC component of the charging bias; and control circuitry to compare an absolute value of the positive peak value with an absolute value of the negative peak value, correct the AC voltage to cause the absolute value of the negative peak value to coincide with the absolute value of the positive peak value when the absolute value of the positive peak value is smaller, and to cause the absolute value of the positive peak value to coincide with the absolute value of the negative peak value when the absolute value of the negative peak value is smaller.
    Type: Grant
    Filed: April 23, 2019
    Date of Patent: April 21, 2020
    Assignee: Ricoh Company, Ltd.
    Inventor: Koichi Kawasaki
  • Patent number: 10579003
    Abstract: An imaging device includes a photoconductive drum charged by a charge roll and opposed by a transfer roll to transfer an image from the drum. The drum becomes biased to a negative voltage by setting charges of negative voltage on both the charge roll and transfer roll. A controller switches the bias of the transfer roll to a positive voltage from the negative voltage and a delta or difference in a charge of the drum is determined from before and after the switching. Based on the delta, the voltage on the charge roll is boosted by a boost voltage to improve the charge on the drum. In this way, deteriorating or defective charge rolls can be still used to charge the drum to a proper voltage for imaging. Techniques for determining the delta, the boost and the magnitude of voltage charges are further embodiments.
    Type: Grant
    Filed: May 21, 2019
    Date of Patent: March 3, 2020
    Assignee: LEXMARK INTERNATIONAL, INC.
    Inventors: Michael Brian Bacelieri, Douglas Anthony Able, Andrew Pryse Dale, Jared Kuohui Lin, Robert Watson McAlpine, Matthew Russell Smither
  • Patent number: 10509344
    Abstract: An electrophotographic image forming apparatus includes: an image carrier that carries and conveys a toner image; a charging member arranged in contact with or close to the image carrier; a charging power supply that charges the image carrier; an exposurer that forms a latent image on the charged image carrier; a developing member arranged close to the image carrier; a developing power supply that develops the latent image and forms a toner image on the image carrier; a transfer member that transfers the toner image to a medium; and a hardware processor that controls the image forming apparatus, wherein the hardware processor obtains a potential of an exposure part and a non-exposure part, on the image carrier after the toner image has been transferred to the medium, determines a charging bias based on a difference between the obtained potentials, and determines a developing bias based on the determined charging bias.
    Type: Grant
    Filed: October 17, 2018
    Date of Patent: December 17, 2019
    Assignee: KONICA MINOLTA, INC.
    Inventor: Masato Kimura
  • Patent number: 10429787
    Abstract: An image forming apparatus includes a movable photosensitive member, first and second corona chargers, an adjusting mechanism, a developing device, a detecting member configured to detect a surface potential of the photosensitive member at a plurality of positions with respect to the widthwise direction of the photosensitive member, an input portion, and a display portion. In accordance with input of an instruction to the input portion, the detecting portion detects at least two surface potentials of three surface potentials including the surface potential of the photosensitive member after being charged by the first and second corona chargers, the surface potential of the photosensitive member after being charged by the first corona charger, and the surface potential of the photosensitive member after being charged by the second corona charger. A detection result of the detecting member is displayed at the display portion.
    Type: Grant
    Filed: July 31, 2017
    Date of Patent: October 1, 2019
    Assignee: Canon Kabushiki Kaisha
    Inventor: Kenichiro Kitajima
  • Patent number: 10359715
    Abstract: An image forming apparatus including: a charging member configured to charge a photosensitive member at a charging portion by a charging voltage in which an alternate-current voltage is superimposed on a direct-current voltage; a transfer member configured to transfer a toner image formed on the photosensitive member to a recording material at a transfer portion; and a controller configured to control the charging voltage, a predetermined area of the photosensitive member passing through the transfer portion during a trailing edge of the recording material passing through the transfer portion, wherein the controller controls a value of a peak-to-peak voltage of the alternate-current voltage when the predetermined area passes through the charging portion to be larger than a value of a peak-to-peak voltage when an area that becomes the image area other than the predetermined area passes through the charging portion.
    Type: Grant
    Filed: January 23, 2018
    Date of Patent: July 23, 2019
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Takeharu Nakada, Tatsuya Kinukawa, Tomoo Akizuki, Masahiko Suzumi, Ryo Morihara, Yusuke Nakazono, Junichi Kubota, Takayuki Kanazawa
  • Patent number: 10216115
    Abstract: A control unit performs control to satisfy TVa<T TVb, where T is a time from a point when irradiation with light by a pre-exposure member is started to a point when a predetermined portion of the photosensitive member which is located at the pre-exposure position when the irradiation is started reaches a charging position, TVa is a time from the point when the irradiation is started to a point when application of a first voltage is started, and TVb is a time from the point when the irradiation is started to a point when application of the second voltage is started.
    Type: Grant
    Filed: March 14, 2018
    Date of Patent: February 26, 2019
    Assignee: CANON KABUSHIKI KAISHA
    Inventor: Hiroyuki Kidaka
  • Patent number: 10185243
    Abstract: A fixing device includes a rotatable fixing member, a rotatable pressuring member and an electric charge supplying device. The fixing member contacts a recording medium having a toner image and heats the recording medium. The pressuring member pressures the recording medium between the fixing member and the pressuring member. The electric charge supplying device electrically discharges electric charges with same polarity as toner and supplies the electric charges to the fixing member. An output current value electrically discharged by the electric charge supplying device is adjusted on the basis of a toner charged amount of the toner image. When the toner charged amount is equal to or more than a threshold value, the output current value is set to a normal current value. When the toner charged amount is less than the threshold value, the output current value is set to a current value higher than the normal current value.
    Type: Grant
    Filed: March 15, 2018
    Date of Patent: January 22, 2019
    Assignee: KYOCERA Doucment Solutions Inc.
    Inventor: Akihiro Kondo
  • Patent number: 10180641
    Abstract: An image forming apparatus includes an image bearing member; a toner image forming device; an image transferring device; a transfer bias applying device; an image fixing device; a sensor for detecting light reflected by the toner image fixed on the sheet; a controller for controlling a leading portion bias applied to the leading portion of the sheet with respect to a sheet feeding direction and a central portion bias applied to the central area of the sheet. The controller forms first and second test images on the leading and central portions, respectively, and sets conditions of the leading and central portion biases on the basis of an output of the sensor, in correlation with a kind of the sheet. A toner deposition amount per unit area of the first test image is smaller than that of the second test image.
    Type: Grant
    Filed: October 5, 2016
    Date of Patent: January 15, 2019
    Assignee: Canon Kabushiki Kaisha
    Inventor: Tomohisa Itagaki
  • Patent number: 10175624
    Abstract: An image forming apparatus includes a rotatable image carrier that carries an image, a charging unit having a rotatable charging member that charges the image carrier, a developing unit that supplies a developer including at least toner to the charged image carrier, and a cleaning unit having a cleaning member that cleans a surface of the image carrier. At least when the image forming apparatus is not performing image formation, the charging member on which the toner from the image carrier is carried is caused to rotate at a peripheral velocity different from a peripheral velocity at which the image carrier rotates.
    Type: Grant
    Filed: August 11, 2017
    Date of Patent: January 8, 2019
    Assignee: FUJI XEROX CO., LTD.
    Inventors: Jin Iwasaki, Ken Ozaki
  • Patent number: 10162282
    Abstract: In one example, an electrostatic printer includes: a photoconductor member; a charging unit to charge the photoconductor member to a charged voltage; an imaging unit to generate a latent electrostatic image on the photoconductor member by discharging areas of the charged photoconductor member; a developer unit to develop a toner image on the photoconductor member using a developer voltage; and a controller to change the developer voltage and to change the charged voltage dependent on the change of the developer voltage to keep the difference between the developer voltage and the charged voltage constant.
    Type: Grant
    Filed: January 29, 2015
    Date of Patent: December 25, 2018
    Assignee: HP INDIGO B.V.
    Inventors: Sasi Moalem, Dmitry Maister, Yossi Cohen, Kobi Shkuri, Michel Assenheimer
  • Patent number: 10151994
    Abstract: An image forming apparatus includes a photosensitive member, a charging roller, a voltage source, a current detecting member, and a setting portion configured to set the DC voltage applied to the charging roller in an image forming period on the basis of a detection result of the detecting member when a DC voltage less than a discharge start voltage is applied from the voltage source to the charging roller in a period other than the image forming period, wherein the setting portion sets the DC voltage so that an absolute value of the DC voltage when an absolute value of the detected current is a first value is larger than an absolute value of the DC voltage when the absolute value of the detected current is a second value smaller than the first value.
    Type: Grant
    Filed: June 28, 2017
    Date of Patent: December 11, 2018
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kota Mori, Takeshi Fujino
  • Patent number: 10146150
    Abstract: At least one partial measurement region is set in the longitudinal direction in a printable region of a photosensitive drum. After the photosensitive drum has been charged to a constant potential with a charging roller, different potentials are set in the partial measurement region and a region excluding the partial measurement region with a laser scanner, partial discharge information of the partial measurement region is detected by a discharge information detection unit, and a bias voltage in image formation that is applied to the charging roller is corrected on the basis of the value of the partial discharge information.
    Type: Grant
    Filed: May 25, 2017
    Date of Patent: December 4, 2018
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kosuke Ikada, Norihito Naito, Takayoshi Kihara, Masataka Mochizuki
  • Patent number: 10116172
    Abstract: A charging device having contactless transmission of electrical energy in order to supply energy to a wireless hand-held device. An electronic circuit for feeding an inductive energy transmitter is designed to adapt energy fed to the inductive energy transmitter in accordance with energy drawn from the inductive energy transmitter. A hand-held device is designed to interrupt the supply of a load when energy is fed into the hand-held device by means of the inductive energy transmitter.
    Type: Grant
    Filed: June 11, 2014
    Date of Patent: October 30, 2018
    Assignee: TRISA HOLDING AG
    Inventors: Franz Fischer, Hanspeter Meier
  • Patent number: 10061223
    Abstract: In an image forming apparatus, a control unit performs a control for determining a surface potential A to determine a first voltage to be applied to a charge roller by a charge voltage application circuit so that a surface potential of a photosensitive drum becomes a first potential. The charge voltage application circuit thereafter applies the first voltage to the charge roller to charge the photosensitive drum. In such a state, the control unit performs a second control to determine a light amount of a laser light source, so that the surface potential of the photosensitive drum becomes a second potential. In such a manner, a potential of a photosensitive drum surface is detected with high accuracy. Moreover, a time taken to detect the potential of the photosensitive drum surface is shortened.
    Type: Grant
    Filed: September 22, 2017
    Date of Patent: August 28, 2018
    Assignee: Canon Kabushiki Kaisha
    Inventor: Kazutaka Yaguchi
  • Patent number: 10031436
    Abstract: A high voltage generation apparatus that supplies a DC voltage to a load includes a current detection circuit that detects a DC flowing through the load. The current detection circuit includes an operational amplifier, and the current detection circuit detects the DC flowing through the load, as a voltage generated in a current detection resistor. The high voltage generation apparatus further includes a voltage detection circuit that detects a DC voltage supplied from a rectification circuit to the load. The current detection circuit includes a bypass circuit that causes a current to flow from a connection portion between the voltage detection circuit and a first input terminal of the operational amplifier to an output terminal of the operational amplifier in a case where the detected value of the DC that flows through the load drops below a predetermined value.
    Type: Grant
    Filed: September 1, 2017
    Date of Patent: July 24, 2018
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Hirohisa Nakajima, Satoshi Ogawara
  • Patent number: 9915889
    Abstract: An image forming apparatus includes an intermediary transfer member, a first image forming portion including a first photosensitive member, a first charging member, a first developing device, a first transfer portion, and a first pre-exposure device, a second image forming portion including a second photosensitive member, a second charging member, a second developing device, a second transfer portion, and a second pre-exposure device, a current detecting portion, and an adjusting portion for adjusting an exposure amount of the first photosensitive member by the first pre-exposure device on the basis of a detection result of the detecting portion in a region on the first photosensitive member having contacted a toner band formed in a maximum amount per unit area on the intermediary transfer member by the second image forming portion in a state in which a transfer current is supplied.
    Type: Grant
    Filed: May 12, 2016
    Date of Patent: March 13, 2018
    Assignee: Canon Kabushiki Kaisha
    Inventor: Shota Soda
  • Patent number: 9904200
    Abstract: An image forming apparatus includes an image-bearing member, which is charged by a charge voltage in which direct and alternating-current voltages are superposed on each other. A toner image is formed on the charged image-bearing member. A current flowing through the charging member is detected when the charge voltage is applied to the charging member. A current, in a frequency band including a discharge current component, is extracted from the detected current. The alternating-current voltage is adjusted based on the current extracted by an extraction unit. Environmental information is acquired. Based on the environmental information acquired by an acquisition unit, a frequency band for extraction performed by the extraction unit is set.
    Type: Grant
    Filed: August 2, 2016
    Date of Patent: February 27, 2018
    Assignee: Canon Kabushiki Kaisha
    Inventor: Hiroyuki Kidaka
  • Patent number: 9880486
    Abstract: An image forming apparatus includes a power supply, a detection member, a plurality of band-pass filters, and a setting unit. The power supply outputs a first charging bias having a first frequency or a second charging bias having a second frequency that is an integral submultiple of the first frequency. The detection member detects a current flowing through a charging member. Each of the plurality of band-pass filters receives an output of a current detected by the detection member. The setting unit uses the band-pass filters for both setting of a peak-to-peak voltage of the first charging bias and setting of a peak-to-peak voltage of the second charging bias.
    Type: Grant
    Filed: September 20, 2016
    Date of Patent: January 30, 2018
    Assignee: CANON KABUSHIKI KAISHA
    Inventor: Takayuki Ganko
  • Patent number: 9804523
    Abstract: A control portion switches first and second modes based on information which influences a toner charging amount. In the first mode, a driving input to the developer bearing member is stopped in response to image formation completion before or at the same time when a trailing end of a charging area reaches the development position, and an application of the development voltage is stopped after the trailing end reaches the development position. In the second mode, The driving input to the developer bearing member is stopped in response to image formation completion before or at the same time when the trailing end reaches the development position, and the application of the development voltage is stopped at a timing after the trailing end reaches the development position and earlier than that in the first mode, or at the same time when the trailing end reaches the development position.
    Type: Grant
    Filed: April 20, 2016
    Date of Patent: October 31, 2017
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Jun Mochizuki, Osamu Ariizumi, Shota Soda
  • Patent number: 9791828
    Abstract: An image forming apparatus includes a latent image bearer, a charger, a blower, a first detector, and a second detector. The charger charges a surface of the latent image bearer. The blower sends air to around the charger. The first detector detects a temperature of the air to be sent to around the charger. The second detector detects a temperature around the charger. The blower performs an operation based on a detection result of the first detector and a detection result of the second detector.
    Type: Grant
    Filed: May 13, 2016
    Date of Patent: October 17, 2017
    Assignee: RICOH COMPANY, LTD.
    Inventors: Hiromitsu Fujiya, Yasuaki Toda
  • Patent number: 9785084
    Abstract: An image forming apparatus includes an apparatus main body, a photoreceptor drum, a charging apparatus, a developing device, a transfer apparatus, a charging bias applying unit, a developing bias applying unit, a bias adjusting unit, and a print density measurement unit. The bias adjusting unit controls the charging bias applying unit to form a plurality of electric potential areas of electric potentials with different magnitudes. The bias adjusting unit applies a predetermined developing bias corresponding to a target electric potential to the developing roller, so as to form a plurality of toner images by electric potential differences between the developing bias and the plurality of electric potential areas. The bias adjusting unit decides a value of a charging bias corresponding to the target electric potential from measurement results of print densities of the plurality of toner images measured by the print density measurement unit.
    Type: Grant
    Filed: September 27, 2016
    Date of Patent: October 10, 2017
    Assignee: KYOCERA Document Solutions Inc.
    Inventors: Minoru Wada, Masaru Hatano, Masaki Kadota, Masahito Ishino, Keisuke Isoda, Atsushi Ishizaki
  • Patent number: 9753393
    Abstract: The image bearing member includes an image bearing member, a charge unit that charges the image bearing member, an exposure unit that exposes the image bearing member by emitting light thereto, a transfer unit that transfers an image formed on the image bearing member, a detection unit that detects a current flowing between the transfer unit and the image bearing member when a voltage is applied to the transfer unit, and a control unit that causes the charge unit to charge the image bearing member through application of a DC voltage, and calculates a surface potential of the image bearing member based on a detection result of the current when the voltage is applied to the transfer unit, after a light whose light amount is higher than a light amount of a light emitted to the image bearing member from the exposure unit is emitted to the image bearing member.
    Type: Grant
    Filed: March 17, 2016
    Date of Patent: September 5, 2017
    Assignee: CANON KABUSHIKI KAISHA
    Inventor: Kazutaka Yaguchi
  • Patent number: 9727001
    Abstract: An image forming apparatus includes an image forming device, an electric current detector, and a controller. The image forming device includes a latent image bearer, a charging rotator, a charging power supply, a latent image writing unit, and a developing unit. The controller (i) determines an uneven electric resistance of the charging rotator in a direction of rotation of the charging rotator, based on a detection result by the electric current detector, (ii) perform, at a predetermined timing, data construction processing to construct change pattern data to change an output value of a voltage from the charging power supply according to a predetermined pattern, based on the uneven electric resistance, and (iii) perform, in a print job to form a toner image in response to an instruction, voltage changing processing to charge the latent image bearer while changing the output value of the voltage, based on the change pattern data.
    Type: Grant
    Filed: April 4, 2016
    Date of Patent: August 8, 2017
    Assignee: Ricoh Company, Ltd.
    Inventors: Satoshi Kaneko, Shuji Hirai, Terumichi Ochi
  • Patent number: 9584674
    Abstract: An image forming apparatus includes a correction unit configured to execute first correction processing to be executed to bring reproduction characteristics of an image formed by an image forming unit close to a target value and second correction processing different from the first correction processing, and an adjustment unit configured to execute a plurality of adjustment processing including the second correction processing, wherein correction processing by the correction unit is set to be executed at a predetermined timing, and wherein in a case that correction processing by the correction unit is executed at the set timing after adjustment processing is executed by the adjustment unit, the image forming apparatus performs control not to execute the second correction processing included in the adjustment processing and to execute the second correction processing after executing the first correction processing by the correction unit.
    Type: Grant
    Filed: February 19, 2015
    Date of Patent: February 28, 2017
    Assignee: Canon Kabushiki Kaisha
    Inventor: Hiroyuki Toriyabe
  • Patent number: 9541861
    Abstract: A developing device includes a toner carrying member, a developer carrying member, a layer thickness restricting portion, a rotation control portion, and a developer carrying member difference voltage control portion. The rotation control portion, when developing is not performed, causes the developer carrying member to rotate forwardly and then to rotate reversely. The developer carrying member difference voltage control portion, in the non-developing forward rotation state, sets a voltage of the developer carrying member that is based on a potential of the toner carrying member, to a voltage that is smaller than a first reference voltage that is set when the developing is performed. The non-developing forward rotation state is a state in which the developer carrying member rotates forwardly when the developing is not performed.
    Type: Grant
    Filed: April 13, 2016
    Date of Patent: January 10, 2017
    Assignee: KYOCERA Document Solutions Inc.
    Inventors: Yasuhiro Tauchi, Yukari Ota
  • Patent number: 9507286
    Abstract: An image forming apparatus having a photosensitive member, a charging member that charges the photosensitive member to form a charged surface on a surface of the photosensitive member, an applying unit that applies to the charging member a charging bias composed of a direct voltage superimposed with an alternating voltage, and a toner image forming unit that forms a toner image on the charged surface. A current flowing through the charging member when the charging bias is applied to the charging member is detected by a current detection unit, and currents of different predetermined frequency components are respectively extracted from the detected current by extraction units. Based on the extracted currents, the alternating voltage of the charging bias is adjusted by an adjustment unit.
    Type: Grant
    Filed: November 27, 2013
    Date of Patent: November 29, 2016
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Jiro Shirakata, Tadashi Fukuda
  • Patent number: 9459565
    Abstract: An image forming apparatus includes an image bearer; a transfer rotator to contact the image bearer to form a transfer nip therebetween; a bias application device to apply, to the transfer rotator, a transfer bias, a cleaning bias to remove toner adhering to the transfer rotator, and a non-image area bias smaller in absolute value than the cleaning bias; and a controller to control the bias application device and set a sheet feeding interval according to a predetermined condition. When the sheet feeding interval exceeds a predetermined threshold, the controller causes the bias application device to apply, to the transfer rotator, the non-image area bias for an application time Z and the cleaning bias for a time X?Z within the sheet feeding interval when X represents the sheet feeding interval, and the application time Z is increased as the sheet feeding interval is increased.
    Type: Grant
    Filed: May 21, 2015
    Date of Patent: October 4, 2016
    Assignee: Ricoh Company, Ltd.
    Inventor: Tomoya Ohmura
  • Patent number: 9436117
    Abstract: An image forming apparatus, includes an image carrier; a power supply; a charging member, to which the power supply applies a direct current (DC) charging voltage, to charge a surface of the image carrier; and a controller. The controller causes the power supply to apply, to the charging member, the DC charging voltage of a sum of a reference voltage VC and a correction amount ?, so that a charged potential VD of the surface of the image carrier assumes a target value that is substantially equal to the reference voltage VC; and to increase an absolute value of the correction amount ? to be added to the reference voltage VC in inverse proportion to an absolute value of the reference voltage VC, when the absolute value of the reference voltage VC is smaller compared to a case in which the absolute value of the reference voltage VC is greater.
    Type: Grant
    Filed: September 17, 2015
    Date of Patent: September 6, 2016
    Assignee: Ricoh Company, Ltd.
    Inventors: Hisashi Kikuchi, Kazuhiko Watanabe, Takaaki Tawada, Eisuke Shimizu
  • Patent number: 9429868
    Abstract: An image forming apparatus includes a controller that executes a collection sequence to collect developer of opposite polarity adhering to a charging member. The controller executes the collection sequence by setting a first potential difference to allow the developer of opposite polarity to move from the charging member to an image bearing member, setting a second potential difference to allow the developer of opposite polarity to move from the image bearing member to a developer bearing member and to allow the developer of regular polarity to move from the developer bearing member to the image bearing member, setting a third potential difference to not allow the developer of regular polarity to move from the image bearing member to the charging member, and setting a fourth potential difference to allow the developer of regular polarity to move from the image bearing member to the developer bearing member.
    Type: Grant
    Filed: August 10, 2015
    Date of Patent: August 30, 2016
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Yusuke Usui, Kuniaki Tamagaki, Akihisa Matsukawa, Takashi Hiramatsu
  • Patent number: 9429865
    Abstract: An image forming apparatus includes an image-bearing member, which is charged by a charge voltage in which direct and alternating-current voltages are superposed on each other. A toner image is formed on the charged image-bearing member. A current flowing through the charging member is detected when the charge voltage is applied to the charging member. A current, in a frequency band including a discharge current component, is extracted from the detected current. The alternating-current voltage is adjusted based on the current extracted by an extraction unit. Environmental information is acquired. Based on the environmental information acquired by an acquisition unit, a frequency band for extraction performed by the extraction unit is set.
    Type: Grant
    Filed: January 5, 2016
    Date of Patent: August 30, 2016
    Assignee: Canon Kabushiki Kaisha
    Inventor: Hiroyuki Kidaka
  • Patent number: 9417594
    Abstract: Until an output voltage of a converter reaches a threshold value, a control part performs switching control, and after the output voltage reaches the threshold value, the control part performs supply voltage control while the state of a switching control signal at the time when the output voltage reaches the threshold value is maintained. Switching control is a control method in which the output voltage is adjusted by adjusting the frequency or duty ratio of the switching control signal that drives a driving part. Supply voltage control is a control method in which the output voltage is adjusted by adjusting the supply voltage that is applied to the primary side of the converter.
    Type: Grant
    Filed: July 11, 2014
    Date of Patent: August 16, 2016
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Miki Naruse, Atsuhiko Yamaguchi
  • Patent number: 9417547
    Abstract: An image forming apparatus includes development sections having development rollers, photosensitive drums, primary transfer rollers disposed opposite to the photosensitive drums in one-to-one correspondence, an intermediate transfer belt, and a voltage application section. The voltage application section includes a first voltage application section and a second voltage application section. In forced toner discharge from the development sections, the first voltage application section applies opposite polarity voltage between each of three upstream primary transfer rollers among the primary transfer rollers and the corresponding one of the photosensitive drums. The second voltage application section applies positive polarity voltage between a most downstream primary transfer roller and the corresponding one of the photosensitive drums.
    Type: Grant
    Filed: November 12, 2015
    Date of Patent: August 16, 2016
    Assignee: KYOCERA Document Solutions Inc.
    Inventor: Tetsuya Toichi
  • Patent number: 9389549
    Abstract: An image forming apparatus has a patch forming unit, a reversing unit, a patch detecting unit, and a fixing condition correcting unit. The patch forming unit forms a patch for fixability test on conveyed paper by a fixing roller having a fixing condition set corresponding to the execution of a print job. The reversing unit reverses the paper on which the patch for fixability test is formed from the front surface to the back surface through a reversing and conveying path. The patch forming unit detects a characteristic value of the patch for fixability test of the reversed paper using a medium sensor which detects the characteristic value of the back surface of the paper. The fixing condition correcting unit corrects the fixing condition based on the detected characteristic value of the patch for fixability test.
    Type: Grant
    Filed: June 24, 2015
    Date of Patent: July 12, 2016
    Assignee: KYOCERA DOCUMENT SOLUTIONS INC.
    Inventor: Tsubasa Miyamae
  • Patent number: 9329521
    Abstract: An image forming apparatus includes a charging member, a charging bias power source, a developing member, a developing bias power source and a controlling device. The charging member electrically charged an image carrier. The charging bias power source applies a DC charging bias to the charging member. The developing member develops a toner image onto the image carrier. The developing bias power source applies an AC and DC developing bias to the developing member. The controlling device carries out, before image forming process, pre-charging control controlling the charging bias power source to electrically charge the image carrier. The controlling device carries out, after the image forming process is started, post-charging control controlling the charging bias power source and developing bias power source to adjust an electrical potential difference between a surface potential of the image carrier and developing bias to a significant electrical potential difference preventing occurrence of image failure.
    Type: Grant
    Filed: September 9, 2014
    Date of Patent: May 3, 2016
    Assignee: KYOCERA Document Solutions Inc.
    Inventor: Shingo Sakato
  • Patent number: 9298120
    Abstract: Non-uniform charged potential of a surface of a photosensitive member is suppressed even when a temperature of a charging member newly mounted to an image forming apparatus by exchange is lower than a temperature inside the image forming apparatus. The image forming apparatus includes the photosensitive member, a charge portion, an applying portion for applying a charging bias voltage to the charge portion, a toner image forming portion for forming a toner image on the photosensitive member, a transfer portion, a fixing portion, a first casing accommodating them, and a second casing having a recording material accommodating portion for accommodating a recording material.
    Type: Grant
    Filed: May 15, 2015
    Date of Patent: March 29, 2016
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masami Hano, Masahiro Makino
  • Patent number: 9285720
    Abstract: An image forming apparatus has an image carrying body, a first electrically conductive member, a bias application device, and a controller. The first electrically conductive member makes contact with the photosensitive layer of the image carrying body The bias application device applies a bias containing an AC bias to the first electrically conductive member. The controller controls the bias application device. The image forming apparatus can execute, while no image formation is being performed, a temperature raising mode in which, with the first electrically conductive member in contact with the image carrying body outside the image formation region, an AC bias having a peak-to-peak value twice as high as the discharge start voltage between the first electrically conductive member and the image carrying body is applied to the first electrically conductive member to raise the temperature of the surface of the image carrying body.
    Type: Grant
    Filed: February 7, 2014
    Date of Patent: March 15, 2016
    Assignee: KYOCERA Document Solutions Inc.
    Inventors: Takahiko Murata, Shigeki Tsukahara, Ai Takagami, Koichi Hayashi, Nobuyuki Hayashi, Yosuke Saito, Maki Ike, Masaki Kadota
  • Patent number: 9256188
    Abstract: An image forming apparatus having image supporting members and developing devices provided for a plurality of colors respectively, and a developing bias source. The developing bias source includes DC power circuits provided for the colors respectively, an AC power circuit provided for use in common for all of the colors, and an element provided for at least one of the colors other than black. The developing bias source generates developing biases by superimposing an AC voltage output from the AC power circuit on DC voltages output from the DC power circuits and applies the developing biases to the respectively corresponding developing devices. The element maintains a constant voltage having a potential of an opposite polarity to a potential of charged toner used for the development. The developing bias source further superimposes the constant voltage on the developing bias for the at least one of the colors other than black.
    Type: Grant
    Filed: March 19, 2015
    Date of Patent: February 9, 2016
    Assignee: KONICA MINOLTA, INC.
    Inventors: Toru Kasamatsu, Mikiyuki Aoki, Yohei Yamada, Kouei Cho
  • Patent number: 9244374
    Abstract: The image forming apparatus includes a process unit, a latent image writer, a power source, and a controller. The process unit is detachably attachable relative to the image forming apparatus and includes, as a single integrated unit, a latent image bearing member to bear a latent image on a surface thereof, a charging device to charge the surface of the latent image bearing member, and a development device to develop the latent image with toner. The controller causes the power source to output a charging bias at a predetermined target level supplied to the charging device. The process unit includes a first storage device to store correction information for calculating the predetermined target level of the charging bias in accordance with a combination of the latent image bearing member and the charging device. The controller corrects the predetermined target level based on the correction information in the first storage device.
    Type: Grant
    Filed: November 3, 2014
    Date of Patent: January 26, 2016
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroyuki Sugiyama, Ryoh Tanoue, Masahiko Shakuto, Tomoko Takahashi, Yoshinori Nakagawa, Ryuji Yoshida, Taichi Urayama, Shotaro Hoshi, Ryusuke Mase, Takamasa Ozeki
  • Patent number: 9213300
    Abstract: In an image forming apparatus, the charging bias supply circuit generates a second charging bias voltage that causes no positive discharge between the charging unit and the photoreceptor drum, during a recovery mode, the charging unit charges the surface of the photoreceptor drum upon application of the second charging bias voltage during the recovery mode, and the cleaning unit rubs the surface of the photoreceptor drum charged by the second charging bias voltage, during the recovery mode.
    Type: Grant
    Filed: October 4, 2013
    Date of Patent: December 15, 2015
    Assignee: Konica Minolta, Inc.
    Inventors: Kuniaki Kashiwakura, Noritoshi Hagimoto, Hokuto Hatano, Eri Kusano
  • Patent number: 9207564
    Abstract: An image forming apparatus includes an image carrier, a holding roller which holds thereon developer attached on the image carrier, a transfer member which transfers a developer image on the image carrier to a transfer medium, a collection device which collects the developer on the holding roller via the image carrier, and a control device which executes a collection control of causing the developer held on the holding roller to move to the image carrier such that the collection device collects the developer via the image carrier. The control device applies to the holding roller a first discharge bias having a polarity same as the developer after the collection control starts until a first time elapses and thereafter applies to the holding roller a second discharge bias having a polarity same as the developer and having an absolute value larger than the first discharge bias.
    Type: Grant
    Filed: October 28, 2014
    Date of Patent: December 8, 2015
    Assignee: Brother Kogyo Kabushiki Kaisha
    Inventors: Mayu Wakamatsu, Masatoshi Shiraki, Daisuke Ishizuka
  • Patent number: 9134645
    Abstract: An image forming apparatus capable of suppressing deterioration of a charger although an amount of use of the charger is actually small is provided. For that purpose, the image forming apparatus executes simple control of discharge current control in which at least one charging bias smaller in number than number of kinds of test biases in full control of the discharge current control is applied to the charger after a power source is turned on and before an image formation start signal is inputted, and on the basis of a current detected by the detector when the charging bias is applied, selects one from a plurality of modes including a first mode in which a charging bias is set by executing the full control of the discharge current control and including a second member in which the charging bias determined by full control of discharge current control without executing the full control of the discharge current control.
    Type: Grant
    Filed: August 27, 2014
    Date of Patent: September 15, 2015
    Assignee: Canon Kabushiki Kaisha
    Inventor: Michihiro Yoshida
  • Patent number: 9110422
    Abstract: An image forming apparatus includes a process unit arranged in the vicinity of the circumference of each photosensitive member and the process unit is configured to act on the photosensitive member in forming a toner image thereon. The image forming apparatus detects a time period since a laser beam emission unit emits a laser beam to the photosensitive member to form an electrostatic latent image for detection until the formed electrostatic latent image for detection or a toner image based on the electrostatic latent image for detection reaches the process unit, and performs color misregistration correction control based on the result of detection. In this case, a control unit at least decreases the light amount of a pre-exposure LED when the electrostatic latent image for detection passes through a position facing the pre-exposure LED.
    Type: Grant
    Filed: January 8, 2015
    Date of Patent: August 18, 2015
    Assignee: Canon Kabushiki Kaisha
    Inventors: Hiroshi Hagiwara, Takamitsu Soda, Akinobu Hirayama, Hiromitsu Kumada, Yoshiko Kubo, Takateru Ohkubo
  • Patent number: 9086667
    Abstract: An image forming apparatus for forming an image on a recording material includes a cartridge, detachably mountable to a main assembly of the image forming apparatus, including a memory and an image forming process member actable on an image bearing member, and a current detecting portion, provided in the main assembly, for detecting a value of current passing through the process member. The current detecting portion detects the value of the current passing through the process member when a voltage is applied to the process member, and the memory stores information for discriminating whether or not the process member is recyclable on the basis of the detected value of the current.
    Type: Grant
    Filed: March 1, 2013
    Date of Patent: July 21, 2015
    Assignee: CANON KABUSHIKI KAISHA
    Inventor: Masataka Mochizuki
  • Patent number: 9063454
    Abstract: An image forming apparatus includes an image forming unit, a charging bias application section, a static eliminating bias application section, and a control section. In the case where the image forming unit causes an image carrier to be rotated without forming an electrostatic latent image on the image carrier, the control section performs a bias control to allow the charging bias application section to apply to a charging section a smaller charging bias than used in forming a toner image and allow the static eliminating bias application section to apply to a static eliminating section a smaller static eliminating bias than used in forming the toner image. The control section performs the bias control to increase respective values of the charging bias and the static eliminating bias every one revolution of the image carrier until the charging bias and the static eliminating bias in forming the toner image are reached.
    Type: Grant
    Filed: September 13, 2013
    Date of Patent: June 23, 2015
    Assignee: KYOCERA Document Solutions Inc.
    Inventor: Hiroka Itani
  • Patent number: 9063496
    Abstract: An image forming apparatus includes a photosensitive drum, a charging roller, a transfer roller, a first bias application unit, a second bias application unit, and a control unit. The charging roller contains an ion conductive material. The first bias application unit applies a first bias to the charging roller. The second bias application unit applies a predetermined bias to the transfer roller. The control unit controls the first bias application unit not to apply the first bias to the charging roller in a non-image forming period in which a toner image is not formed on the photosensitive drum. The control unit controls the second bias application unit to apply the second bias, which is a bias that can electrically charge the surface of the photosensitive drum, to the transfer roller in the non-image forming period.
    Type: Grant
    Filed: April 22, 2013
    Date of Patent: June 23, 2015
    Assignee: KYOCERA DOCUMENT SOLUTIONS INC.
    Inventors: Shingo Sakato, Takuji Watanabe