Patents by Inventor Hirokazu Ishii

Hirokazu Ishii has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20140248064
    Abstract: An image forming apparatus includes a rotatable image bearing member, a nip forming member, and a power source. The rotatable image bearing member bears a toner image on a surface thereof and rotates. The nip forming member contacts the surface of the image bearing member to form a transfer nip therebetween. The power source applies a transfer bias to the transfer nip to transfer the toner image from the image bearing member onto a recording medium interposed in the transfer nip. The transfer bias includes a superimposed transfer bias in which an alternating current (AC) component is superimposed on a direct current (DC) component and a polarity of the superimposed transfer bias changes with time. A phase difference between an AC voltage and an AC current output from the power source is equal to or less than 0.47 cycles.
    Type: Application
    Filed: February 5, 2014
    Publication date: September 4, 2014
    Inventors: Shinya TANAKA, Hirokazu ISHII, Yasunobu SHIMIZU, Takehide MIZUTANI, Keigo NAKAMURA
  • Patent number: 8797619
    Abstract: An image processing apparatus combines a background image, handwritten image, and a standard image. A reference image acquired by increasing the luminance value of the background image and the standard image is printed on a recording sheet. A recording sheet is read after being filled in, and a region whose luminance value is lower than a predetermined threshold value and a region indicated by standard image mask data are extracted. The extracted regions are combined with the background image and printed. In particular, the standard image mask data indicates a region in the standard image which is easily affected by a background color of a paper, so that color adjustment is performed on the region in the extracted image which is indicated by the mask data. As a result, the region in the standard image is prevented from being affected by the background color of the recording sheet in the combined result, and the images can be combined and printed according to the original color of the standard image.
    Type: Grant
    Filed: August 6, 2009
    Date of Patent: August 5, 2014
    Assignee: Canon Kabushiki Kaisha
    Inventors: Hideyuki Kido, Hirokazu Ishii
  • Patent number: 8787806
    Abstract: An image forming apparatus includes a transfer device to transfer a toner image formed on an image bearing member onto a recording medium, a sheet separation device to separate the recording medium from the image bearing member, a sheet separation bias application device to apply to the sheet separation device a sheet separation bias in which an alternating current (AC) component is superimposed on a direct current (DC) component, and a transfer bias application device to selectively apply to the transfer device one of a DC transfer bias having a DC component and a superimposed transfer bias in which an AC component is superimposed on a DC component. Upon application of the superimposed transfer bias to the transfer device, the sheet separation bias applied to the sheet separation device is changed from the sheet separation bias applied upon application of the DC transfer bias to the transfer device.
    Type: Grant
    Filed: September 4, 2012
    Date of Patent: July 22, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Keigo Nakamura, Hirokazu Ishii, Yasunobu Shimizu, Hiromi Ogiyama, Shinya Tanaka
  • Publication number: 20140079418
    Abstract: An image forming apparatus includes a power source to output a voltage having an alternating waveform to transfer a toner image from an image bearing member to a recording medium. A time-averaged value (Vave) of the voltage has a polarity in a transfer direction, in which the toner image is transferred from the image bearing member to the recording medium, and an absolute value of the time-averaged value is greater than a midpoint value (Voff) of the voltage intermediate between a maximum value and a minimum value of the voltage. As a roughness of the recording medium increases, a duty ratio (Duty) expressed by A/(A+B) is reduced, where A is an area of the waveform of the voltage in a return direction opposite the transfer direction relative to the midpoint value in one cycle and B is an area in the transfer direction relative to the midpoint value.
    Type: Application
    Filed: September 10, 2013
    Publication date: March 20, 2014
    Inventors: Shinya TANAKA, Hirokazu Ishii, Yasunobu Shimizu, Keigo Nakamura
  • Publication number: 20140029988
    Abstract: A novel image forming apparatus includes a photoreceptor to bear an electrostatic latent image on a surface thereof, a developing device to develop the electrostatic latent image into a toner image, an intermediate transfer member onto which the electrostatic latent image is transferred, a primary transfer member to apply a primary transfer bias to the intermediate transfer member to transfer the toner image thereto, a secondary transfer member supplied with a secondary transfer bias to transfer the toner image from the intermediate transfer member onto a recording medium, and a transfer bias power source to selectively apply to the secondary transfer member one of a secondary transfer bias consisting of a direct current (DC) voltage in a DC transfer mode and a secondary transfer bias consisting of a superimposed bias in which an alternating voltage is superimposed on a DC voltage.
    Type: Application
    Filed: June 14, 2013
    Publication date: January 30, 2014
    Inventors: Yasunobu SHIMIZU, Shinya TANAKA, Hirokazu ISHII, Keigo NAKAMURA
  • Publication number: 20140002706
    Abstract: A lens driving control apparatus includes an image pickup element that includes an imaging pixel and a focus detection pixel and that performs a photoelectric conversion of an object image, a readout unit that reads image signals from the focus detection pixel with a predetermined period, a storage unit that stores the image signals read by the readout unit, an addition unit that adds a plurality of signals in time-series continuous frames of the image signals, a focus detection unit that performs focus detection based on an addition result by the addition unit, and a lens controller that controls a driving speed of a lens based on the addition number of times by the addition unit and a result of the focus detection unit, and the lens controller performs a control so that the driving speed of the lens is reduced when the addition number of times increases.
    Type: Application
    Filed: March 19, 2012
    Publication date: January 2, 2014
    Applicant: CANON KABUSHIKI KAISHA
    Inventor: Hirokazu Ishii
  • Patent number: 8611738
    Abstract: An image capturing apparatus includes an image sensor having a focus detection pixel group including a plurality of focus detection pixels that receive light passing through a part of a pupil area of an imaging lens for forming an object image and an image forming pixel group including a plurality of image forming pixels that receive light passing through the whole of the pupil area of the imaging lens; and an image processing unit that generates an image signal corresponding to the position of each of the focus detection pixels by using at least either of a signal of the focus detection pixel at the position and signals of neighboring image forming pixels of the focus detection pixel at the position, depending on the size of an aperture of the focus detection pixels.
    Type: Grant
    Filed: September 10, 2010
    Date of Patent: December 17, 2013
    Assignee: Canon Kabushiki Kaisha
    Inventor: Hirokazu Ishii
  • Publication number: 20130308040
    Abstract: An image capturing apparatus includes: an imaging element including a first photoelectric conversion cell that outputs a first signal for phase difference detection obtained by detecting a plurality of light fluxes transmitted through different exit pupils of a photographing optical system using a plurality of focus detection pixels and a second photoelectric conversion cell that outputs a second signal for image generation obtained by detecting an object image transmitted through the photographing optical system using an imaging pixel. A contrast calculating unit calculates contrast information on the object image based on at least one of the first signal and the second signal; a focus detecting unit performs focus detection using a phase difference method on the basis of the first signal, and outputs an estimate for focus adjustment; a reliability estimating unit estimates reliability of a result obtained by the focus detecting unit.
    Type: Application
    Filed: May 10, 2013
    Publication date: November 21, 2013
    Applicant: CANON KABUSHIKI KAISHA
    Inventor: Hirokazu Ishii
  • Publication number: 20130308968
    Abstract: An image forming apparatus includes a transfer bias output device and an information receiving device. The transfer bias output device outputs a transfer bias including a superimposed bias composed of an AC bias superimposed on a DC bias to form a transfer electric field in a transfer nip between an image bearing member bearing a toner image and a nip forming member, to transfer the toner image onto a recording medium in the transfer nip. A controller operatively connected to the information receiving device and the transfer bias output device causes the transfer bias output device to change a target output of a peak-to-peak voltage of the AC bias based on information received by the information receiving device that affects transfer of the toner image and to reduce a target output of the DC bias as the target output value of the peak-to-peak voltage of the AC bias increases.
    Type: Application
    Filed: May 14, 2013
    Publication date: November 21, 2013
    Inventors: Shinya TANAKA, Hirokazu Ishii, Yasunobu Shimizu, Keigo Nakamura
  • Publication number: 20130236201
    Abstract: An image forming apparatus includes a toner forced consumption control unit that performs toner forced consumption control in which toner in a developing unit is forcibly consumed when a certain condition to perform the toner forced consumption control is met. The certain condition to perform the toner forced consumption control includes a specific performance condition that a transfer bias switching condition to switch a transfer bias to a superimposed transfer bias in which an alternating current component is superimposed on a direct current component, from a direct current transfer bias is met. When the specific performance condition is met, the toner forced consumption control unit performs preliminary toner forced consumption control in which the toner forced consumption control is performed before an image forming operation using the superimposed transfer bias is started.
    Type: Application
    Filed: March 5, 2013
    Publication date: September 12, 2013
    Inventors: Takehide Mizutani, Shinya Tanaka, Yasunobu Shimizu, Hirokazu Ishii, Keigo Nakamura
  • Publication number: 20130195483
    Abstract: A transfer device includes a transfer bias power source, a switching device, and a sheet dependent condition setting device. The transfer bias power source applies to a transfer member, based on sheet dependent conditions for a recording medium onto which a toner image is transferred, one of a DC transfer bias and a superimposed transfer bias including an alternating current (AC) component superimposed on a DC component. The switching device switches a transfer mode between a DC transfer mode in which the DC transfer bias is applied to the transfer device and a superimposed-bias transfer mode in which the superimposed transfer bias is applied to the transfer device. The sheet dependent condition setting device sets arbitrarily at least one of the sheet dependent conditions for the recording medium at the superimposed-bias transfer mode. The sheet dependent conditions include a DC component value and an AC component value.
    Type: Application
    Filed: January 23, 2013
    Publication date: August 1, 2013
    Inventors: Yasunobu Shimizu, Shinya Tanaka, Hiromi Ogiyama, Hirokazu Ishii, Keigo Nakamura
  • Publication number: 20130177329
    Abstract: An image forming apparatus includes an image carrier that carries an electrostatic latent image; a developing unit that develops the electrostatic latent image using a toner; an intermediate transfer body onto which toner image is transferred; a secondary transfer member that comes in contact with a surface of the intermediate transfer body; a power supply that outputs a voltage for transferring the toner image on the intermediate transfer body onto a recording member; and a protective agent supply unit that applies a protective agent including zinc stearate and boron nitride onto a surface of the image carrier. The voltage is alternatively switched in a transfer direction and an opposite direction. The voltage in the transfer direction enables transfer of the toner image from the intermediate transfer body to the recording member, and the voltage in the opposite direction has polarity opposite to polarity of the voltage in the transfer direction.
    Type: Application
    Filed: January 11, 2013
    Publication date: July 11, 2013
    Inventors: Shinya Tanaka, Hirokazu Ishii, Hiromi Ogiyama, Yasunobu Shimizu, Keigo Nakamura
  • Publication number: 20130164011
    Abstract: An image forming apparatus includes an image bearing member, a transfer member disposed facing the image bearing member to form a transfer region therebetween, a transfer bias application device to apply to the transfer region a transfer bias including a direct current (DC) component and an alternating current (AC) component to transfer the toner image onto the recording medium as the recording medium passes through the transfer region, and a controller operatively connected to the transfer bias application device to allow, during a bias change period in a sheet absent period in which the image bearing member rotates and no recording medium passes through the transfer region, the transfer bias application device to selectively apply to the transfer region one of the transfer bias without the AC component and the transfer bias with a peak-to-peak voltage of the AC component less than that applied in image formation.
    Type: Application
    Filed: December 18, 2012
    Publication date: June 27, 2013
    Inventors: Keigo Nakamura, Yasunobu Shimizu, Hiromi Ogiyama, Hirokazu Ishii, Shinya Tanaka
  • Patent number: 8466992
    Abstract: An image processing apparatus for processing an output of an image pickup element having ordinary pixels arranged in a horizontal direction and a vertical direction and functional pixels arranged discretely between the ordinary pixels, is arranged to estimate an image signal at a position of the functional pixel by a gain correction operation of outputs of the functional pixels, estimate an output of the image signal at the position of the functional pixel on the basis of outputs of reference pixels selected from the ordinary pixels around the functional pixel, and select the image signal at the position of the functional pixel on the basis of an estimation result by the gain correction from one or a plurality of estimation results obtained using the reference pixels.
    Type: Grant
    Filed: December 3, 2010
    Date of Patent: June 18, 2013
    Assignee: Canon Kabushiki Kaisha
    Inventor: Hirokazu Ishii
  • Publication number: 20130136468
    Abstract: An image forming apparatus includes an image bearing member to bear a toner image on a surface thereof, a transfer device to transfer the toner image onto a recording medium, and a transfer bias power source to apply to the transfer device a superimposed transfer bias in which an alternating current (AC) component is superimposed on a direct current (DC) component in a superimposed transfer mode to transfer the toner image. The superimposed transfer bias has a waveform in which a first polarity in a direction of transferring the toner image onto the recording medium and a second polarity opposite the first polarity switch alternately. The superimposed transfer bias is output such that a standard value of each of the DC component and the AC component is multiplied by a respective correction ratio, and the correction ratio of the DC component is different from that of the AC component.
    Type: Application
    Filed: November 1, 2012
    Publication date: May 30, 2013
    Inventors: Yasunobu SHIMIZU, Hiromi Ogiyama, Hirokazu Ishii, Shinya Tanaka, Keigo Nakamura
  • Publication number: 20130089363
    Abstract: A transfer device comprises a freely rotatable transferring member contacting an image bearing member to form a transfer nip therebetween; a transfer bias applying member to apply a first bias created by superimposing an alternating current component on a direct current component to the transferring member to transfer a toner image borne on the image bearing member to a recording medium in the transfer nip; and an applicator to apply a protective agent to a surface of the transferring member.
    Type: Application
    Filed: October 8, 2012
    Publication date: April 11, 2013
    Inventors: Ryuuichi Mimbu, Shinya Tanaka, Hirokazu Ishii, Yasunobu Shimizu, Keigo Nakamura, Hiromi Ogiyama, Kenji Sengoku
  • Publication number: 20130064559
    Abstract: An image forming apparatus includes a transfer device to transfer a toner image formed on an image bearing member onto a recording medium, a sheet separation device to separate the recording medium from the image bearing member, a sheet separation bias application device to apply to the sheet separation device a sheet separation bias in which an alternating current (AC) component is superimposed on a direct current (DC) component, and a transfer bias application device to selectively apply to the transfer device one of a DC transfer bias having a DC component and a superimposed transfer bias in which an AC component is superimposed on a DC component. Upon application of the superimposed transfer bias to the transfer device, the sheet separation bias applied to the sheet separation device is changed from the sheet separation bias applied upon application of the DC transfer bias to the transfer device.
    Type: Application
    Filed: September 4, 2012
    Publication date: March 14, 2013
    Inventors: Keigo NAKAMURA, Hirokazu Ishii, Yasunobu Shimizu, Hiromi OGIYAMA, Shinya TANAKA
  • Patent number: 8396386
    Abstract: An image forming apparatus including a latent image bearing member, a charger to evenly charge a surface of the latent image bearing member, an electrostatic latent image forming device to form an electrostatic latent image on the surface of the latent image bearing member, a developing device to develop the electrostatic latent image into a toner image using toner, a transfer bias application device to apply a transfer bias to an image transfer area where the latent image bearing member faces a recording medium, a pre-transfer neutralizing device to reduce an electric potential at a portion on the surface of the latent image bearing member, a surface electric potential detector to detect an electric potential at the surface of the latent image bearing member, and a radiation amount control device to control an amount of radiation from the pre-transfer neutralizing device.
    Type: Grant
    Filed: March 13, 2012
    Date of Patent: March 12, 2013
    Assignee: Ricoh Company, Limited
    Inventor: Hirokazu Ishii
  • Publication number: 20120262604
    Abstract: An image pickup apparatus includes an image pickup element that includes imaging pixels and focus detection pixels and that performs a photoelectric conversion of an object image, a readout unit that reads a pair of image signals from the focus detection pixels with a predetermined period, a storage unit that stores the pair of image signals read by the readout unit and optical information of the pair of image signals, an addition unit that adds a plurality of signals of time-series continuous frames of the pair of image signals, and a conversion coefficient determination unit that determines a conversion coefficient that converts an image shift amount of a pair of image signals of an addition frame obtained by the addition unit into a defocus amount, and the conversion coefficient determination unit determines the conversion coefficient of the addition frame based on the time-series continuous optical information.
    Type: Application
    Filed: April 9, 2012
    Publication date: October 18, 2012
    Applicant: CANON KABUSHIKI KAISHA
    Inventor: Hirokazu Ishii
  • Patent number: 8290411
    Abstract: An image forming apparatus including a latent image bearing member, a charger to evenly charge a surface of the latent image bearing member, an electrostatic latent image forming device to form an electrostatic latent image on the surface of the latent image bearing member, a developing device to develop the electrostatic latent image into a toner image using toner, a transfer bias application device to apply a transfer bias to an image transfer area where the latent image bearing member faces a recording medium, a pre-transfer neutralizing device to reduce an electric potential at a portion on the surface of the latent image bearing member, a surface electric potential detector to detect an electric potential at the surface of the latent image bearing member, and a radiation amount control device to control an amount of radiation from the pre-transfer neutralizing device based on a detection result obtained by the surface electric potential detector.
    Type: Grant
    Filed: July 2, 2009
    Date of Patent: October 16, 2012
    Assignee: Ricoh Company, Limited
    Inventor: Hirokazu Ishii