Patents by Inventor Yoshio Nakazawa

Yoshio Nakazawa 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).

  • Patent number: 9457563
    Abstract: An ink jet printer is provided with a driving signal generating section which generates a driving signal for driving a piezoelectric element, a residual vibration detecting section, a control IC which includes the residual vibration detecting section, and a connection terminal which connects the piezoelectric element, an input terminal to which the driving signal is supplied and an output terminal from which an output signal of the residual vibration detecting section is supplied, a first external wiring which is connected to the input terminal and through which the driving signal is supplied, and a second external wiring which is connected to the output terminal and through which the output signal of the residual vibration detecting section is supplied. A resistance value per unit length of the second external wiring is larger than a resistance value per unit length of the first external wiring.
    Type: Grant
    Filed: September 9, 2014
    Date of Patent: October 4, 2016
    Assignee: Seiko Epson Corporation
    Inventors: Yoshio Nakazawa, Masahiko Yoshida, Kazuhito Fujisawa, Atsushi Akiyama, Osamu Shinkawa
  • Patent number: 9434159
    Abstract: An ink jet printer is provided with a piezoelectric element which is provided corresponding to a pressure chamber in order to discharge liquid droplets, a driving signal generating section which generates a driving signal, a residual vibration detecting section which detects changes in an electromotive force of the piezoelectric element in accordance with the residual vibration inside the pressure chamber which occur after the driving signal is applied, a first switch which switches whether or not a driving signal is applied to the piezoelectric element, and a second switch which switches whether or not a change in the electromotive force is supplied to a first high-pass filter, where the second switch and the residual vibration detecting section are connected via a first capacitor of the first high-pass filter.
    Type: Grant
    Filed: August 12, 2014
    Date of Patent: September 6, 2016
    Assignee: Seiko Epson Corporation
    Inventors: Yoshio Nakazawa, Kazuhito Fujisawa, Masahiko Yoshida, Atsushi Akiyama, Osamu Shinkawa
  • Publication number: 20150091960
    Abstract: An ink jet printer is provided with a driving signal generating section which generates a driving signal for driving a piezoelectric element, a residual vibration detecting section, a control IC which includes the residual vibration detecting section, and a connection terminal which connects the piezoelectric element, an input terminal to which the driving signal is supplied and an output terminal from which an output signal of the residual vibration detecting section is supplied, a first external wiring which is connected to the input terminal and through which the driving signal is supplied, and a second external wiring which is connected to the output terminal and through which the output signal of the residual vibration detecting section is supplied. A resistance value per unit length of the second external wiring is larger than a resistance value per unit length of the first external wiring.
    Type: Application
    Filed: September 9, 2014
    Publication date: April 2, 2015
    Inventors: Yoshio NAKAZAWA, Masahiko YOSHIDA, Kazuhito FUJISAWA, Atsushi AKIYAMA, Osamu SHINKAWA
  • Publication number: 20150054876
    Abstract: An ink jet printer is provided with a piezoelectric element which is provided corresponding to a pressure chamber in order to discharge liquid droplets, a driving signal generating section which generates a driving signal, a residual vibration detecting section which detects changes in an electromotive force of the piezoelectric element in accordance with the residual vibration inside the pressure chamber which occur after the driving signal is applied, a first switch which switches whether or not a driving signal is applied to the piezoelectric element, and a second switch which switches whether or not a change in the electromotive force is supplied to a first high-pass filter, where the second switch and the residual vibration detecting section are connected via a first capacitor of the first high-pass filter.
    Type: Application
    Filed: August 12, 2014
    Publication date: February 26, 2015
    Inventors: Yoshio NAKAZAWA, Kazuhito FUJISAWA, Masahiko YOSHIDA, Atsushi AKIYAMA, Osamu SHINKAWA
  • Patent number: 8311459
    Abstract: A developing apparatus includes: a housing which contains toner; a toner supporting roller; and a regulating blade, wherein bias voltage is applied to the regulating blade, the toner includes, an insulating external additive and an electrically-conductive external additive, satisfies any of the following first to third conditions, the first condition: a volume average grain diameter of the electrically-conductive external additive is larger than a volume average grain diameter of the insulating external additive, the second condition: a volume average grain diameter of the electrically-conductive external additive is larger than a volume average grain diameter of the insulating external additive in which coverage in the toner is higher than that of the electrically-conductive external additive, and the third condition: coverage of the electrically-conductive external additive in the toner is higher than coverage of the insulating external additive that is larger in volume average grain diameter than the elect
    Type: Grant
    Filed: March 11, 2010
    Date of Patent: November 13, 2012
    Assignee: Seiko Epson Corporation
    Inventors: Yoichi Yamada, Tomohiro Aruga, Daisuke Matsumoto, Yoshio Nakazawa
  • Publication number: 20120236063
    Abstract: A discharge testing device comprising: a discharge controller discharging a liquid droplet from a nozzle such that a discharge testing period including a discharge period; a detection signal acquiring unit acquiring a detection signal; a low-pass filter eliminating a high frequency component from the detection signal; a first amplifier amplifying the detection signal to generate a first amplification signal; a restricting unit restricting signal strength of the first amplification signal during a restriction period included in the discharge testing period to predetermined strength; a second amplifier amplifying the first amplification signal to generate a second amplification signal; and a determinator determining whether a liquid droplet is normally discharged based on signal strength based on signal strength of a second amplification signal during a sampling period after a predetermined time elapses from the restriction period.
    Type: Application
    Filed: March 16, 2012
    Publication date: September 20, 2012
    Applicant: SEIKO EPSON CORPORATION
    Inventor: Yoshio NAKAZAWA
  • Publication number: 20100239328
    Abstract: A developing apparatus includes: a housing which contains toner; a toner supporting roller; and a regulating blade, wherein bias voltage is applied to the regulating blade, the toner includes, an insulating external additive and an electrically-conductive external additive, satisfies any of the following first to third conditions, the first condition: a volume average grain diameter of the electrically-conductive external additive is larger than a volume average grain diameter of the insulating external additive, the second condition: a volume average grain diameter of the electrically-conductive external additive is larger than a volume average grain diameter of the insulating external additive in which coverage in the toner is higher than that of the electrically-conductive external additive, and the third condition: coverage of the electrically-conductive external additive in the toner is higher than coverage of the insulating external additive that is larger in volume average grain diameter than the elect
    Type: Application
    Filed: March 11, 2010
    Publication date: September 23, 2010
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Yoichi YAMADA, Tomohiro ARUGA, Daisuke MATSUMOTO, Yoshio NAKAZAWA
  • Patent number: 7680427
    Abstract: A high voltage power supply apparatus according to the present invention is a high voltage power supply apparatus that applies a bias voltage at least to a developing roller of a developing unit, the apparatus comprising: a transformer that increases an AC voltage and includes a main winding and a sub winding on the secondary side thereof; a first capacitor whose first end is connected to a common connection point between the main and sub windings; a second capacitor whose first end is connected to one end of the sub winding which is not the common connection point side; a zener diode whose both ends are connected to the second end of the first capacitor and second end of the second capacitor; and a DC voltage application section that applies a DC voltage to the zener diode, wherein a voltage generated in the second end of the first capacitor is used as a voltage to be applied to the developing roller.
    Type: Grant
    Filed: April 24, 2007
    Date of Patent: March 16, 2010
    Assignee: Seiko Epson Corporation
    Inventor: Yoshio Nakazawa
  • Patent number: 7532827
    Abstract: An image-forming apparatus for forming an image by heating a medium, the image-forming apparatus includes a connector connectable to a heating unit that heats the medium; a conmmercial power supply that generates power to be supplied to the heating unit; a switch system, provided between the heating unit and the conmmercial power supply, that switches the supply of the power to the heating unit on or off; and a switch control unit that controls the switch system based on the heating unit type.
    Type: Grant
    Filed: March 7, 2006
    Date of Patent: May 12, 2009
    Assignee: Seiko Epson Corporation
    Inventor: Yoshio Nakazawa
  • Publication number: 20080226317
    Abstract: An image forming apparatus, includes: a plurality of image forming stations each of which includes a photosensitive member and a charger that charges a surface of the photosensitive member to a specified surface potential, and is adapted to execute an image forming operation of forming an electrostatic latent image on the photosensitive member charged by the charger and developing the electrostatic latent image with toner to form an image; a plurality of direct-current bias generators that are provided corresponding to the respective plurality of chargers and generate direct-current voltages as direct-current components of charging biases to be given to the chargers; a plurality of series resistors that are provided corresponding to the respective plurality of chargers and electrically connect the plurality of chargers and the direct-current bias generators corresponding to the chargers in a one-to-one relationship; an alternating-current bias generator that generates alternating-current voltages as alternati
    Type: Application
    Filed: March 4, 2008
    Publication date: September 18, 2008
    Applicant: SEIKO EPSON CORPORATION
    Inventor: Yoshio NAKAZAWA
  • Publication number: 20070248375
    Abstract: A high voltage power supply apparatus according to the present invention is a high voltage power supply apparatus that applies a bias voltage at least to a developing roller of a developing unit, the apparatus comprising: a transformer that increases an AC voltage and includes a main winding and a sub winding on the secondary side thereof; a first capacitor whose first end is connected to a common connection point between the main and sub windings; a second capacitor whose first end is connected to one end of the sub winding which is not the common connection point side; a zener diode whose both ends are connected to the second end of the first capacitor and second end of the second capacitor; and a DC voltage application section that applies a DC voltage to the zener diode, wherein a voltage generated in the second end of the first capacitor is used as a voltage to be applied to the developing roller.
    Type: Application
    Filed: April 24, 2007
    Publication date: October 25, 2007
    Applicant: SEIKO EPSON CORPORATION
    Inventor: Yoshio Nakazawa
  • Patent number: 7184677
    Abstract: An image forming apparatus which repeats image create/transfer processing while rotating a photosensitive member and a transfer medium in a sub scanning direction and thereafter transferring the toner image onto the transfer medium, for a plurality of toner colors which are different from each other, to thereby lay toner images in respective toner colors over each other on the transfer medium and accordingly form a color image. The apparatus corrects transfer start positions of toner image in at least one or more toner colors out of the plurality of toner colors based on a registration control amount which is necessary to correct relative registration deviations among toner images on the transfer medium.
    Type: Grant
    Filed: September 30, 2004
    Date of Patent: February 27, 2007
    Assignee: Seiko Epson Corporation
    Inventors: Kuniaki Tanaka, Nozomu Inoue, Yoshio Nakazawa, Tsuyoshi Kowari, Keiichi Taguchi
  • Publication number: 20060222379
    Abstract: An image-forming apparatus for forming an image by heating a medium, the image-forming apparatus includes a connector connectable to a heating unit that heats the medium; a conmmercial power supply that generates power to be supplied to the heating unit; a switch system, provided between the heating unit and the conmmercial power supply, that switches the supply of the power to the heating unit on or off; and a switch control unit that controls the switch system based on the heating unit type.
    Type: Application
    Filed: March 7, 2006
    Publication date: October 5, 2006
    Inventor: Yoshio Nakazawa
  • Publication number: 20060177247
    Abstract: Power transmission members (91), which transmit rotational drive force from a drive source (81), such as a motor, to an intermediate transfer drum (41D) is elastically deformed due to a load change which is generated as a cleaning part (49) contacts and moves away from the intermediate transfer drum (41D). Registration control amounts (Ra, Rb and Rc) attributed to the elastic deformation are obtained in advance. Transfer start positions for toner images in at least one or more toner colors out of four toner colors are corrected based on the registration control amounts (Ra, Rb and Rc), whereby registration deviations are suppressed to minimum and a high-quality color image is obtained.
    Type: Application
    Filed: April 6, 2006
    Publication date: August 10, 2006
    Applicant: Seiko Epson Corporation
    Inventors: Kuniaki Tanaka, Nozomu Inoue, Yoshio Nakazawa, Tsuyoshi Kowari, Keiichi Taguchi
  • Publication number: 20050053389
    Abstract: Power transmission members (91), which transmit rotational drive force from a drive source (81), such as a motor, to an intermediate transfer drum (41D) is elastically deformed due to a load change which is generated as a cleaning part (49) contacts and moves away from the intermediate transfer drum (41D). Registration control amounts (Ra, Rb and Rc) attributed to the elastic deformation are obtained in advance. Transfer start positions for toner images in at least one or more toner colors out of four toner colors are corrected based on the registration control amounts (Ra, Rb and Rc), whereby registration deviations are suppressed to minimum and a high-quality color image is obtained.
    Type: Application
    Filed: September 30, 2004
    Publication date: March 10, 2005
    Applicant: Seiko Epson Corporation
    Inventors: Kuniaki Tanaka, Nozomu Inoue, Yoshio Nakazawa, Tsuyoshi Kowari, Keiichi Taguchi
  • Patent number: 6832060
    Abstract: An image forming apparatus and method that repeats image create/transfer processing, in which serial processing of forming a toner image on a photosensitive member while rotating the photosensitive member and a transfer medium in a sub scanning direction and thereafter transferring the toner image onto the transfer medium, for a plurality of toner colors which are different from each other. The apparatus and method lay toner images in the respective toner colors over each other on said transfer medium and accordingly form a color image. Correcting transfer start positions of toner images in at least one or more toner colors out of the plurality of toner colors is based on a registration control amount which is necessary to correct relative registration deviations among toner images on the transfer medium.
    Type: Grant
    Filed: August 4, 2003
    Date of Patent: December 14, 2004
    Assignee: Seiko Epson Corporation
    Inventors: Kuniaki Tanaka, Nozomu Inoue, Yoshio Nakazawa, Tsuyoshi Kowari, Keiichi Taguchi
  • Publication number: 20040022561
    Abstract: Power transmission members (91), which transmit rotational drive force from a drive source (81), such as a motor, to an intermediate transfer drum (41D) is elastically deformed due to a load change which is generated as a cleaning part (49) contacts and moves away from the intermediate transfer drum (41D). Registration control amounts (Ra, Rb and Rc) attributed to the elastic deformation are obtained in advance. Transfer start positions for toner images in at least one or more toner colors out of four toner colors are corrected based on the registration control amounts (Ra, Rb and Rc), whereby registration deviations are suppressed to minimum and a high-quality color image is obtained.
    Type: Application
    Filed: August 4, 2003
    Publication date: February 5, 2004
    Applicant: Seiko Epson Corporation
    Inventors: Kuniaki Tanaka, Nozomu Inoue, Yoshio Nakazawa, Tsuyoshi Kowari, Keiichi Taguchi
  • Patent number: 6633737
    Abstract: Power transmission members which transmit rotational drive force from a drive source such as a motor, to an intermediate transfer drum is elastically deformed due to a load change which is generated as a cleaning part contacts and moves away from the intermediate transfer drum. Registration control amounts (Ra, Rb and Rc) attributed to the elastic deformation are obtained in advance. Transfer start positions for toner images in at least one or more toner colors out of four toner colors are corrected based on the registration control amounts (Ra, Rb and Rc), whereby registration deviations are suppressed to minimum and a high-quality color image is obtained.
    Type: Grant
    Filed: July 5, 2001
    Date of Patent: October 14, 2003
    Assignee: Seiko Epson Corporation
    Inventors: Kuniaki Tanaka, Nozomu Inoue, Yoshio Nakazawa, Tsuyoshi Kowari, Keiichi Taguchi
  • Patent number: 6597878
    Abstract: A toner quantity measuring apparatus in which an input offset voltage is applied to the output side of an irradiation quantity monitoring light receiving element, so that a light emitting element remains turned off unless a light quantity control signal exceeds a predetermined signal level. Prior to irradiation of light upon an intermediate transfer belt and measurement of a toner quantity, a light quantity control signal below the predetermined signal level is supplied to an irradiation quantity adjusting unit and the light emitting element is turned off without fail. A memory stores, as a dark output voltage, an output voltage from a reflection quantity detecting unit upon the turning off. Light reflected from the intermediate transfer belt is split into p-polarized and s-polarized light to detect a toner quantity and colors of the toner.
    Type: Grant
    Filed: September 26, 2001
    Date of Patent: July 22, 2003
    Assignee: Seiko Epson Corporation
    Inventors: Hiroshi Nakazato, Takashi Hama, Yoshio Nakazawa
  • Patent number: 6415114
    Abstract: In an apparatus, first and second processing modes are prepared to determine an optimal development bias. Either one of the first processing mode and the second processing mode is selected as a processing mode in accordance with an operation status of the apparatus. Hence, it is possible to select and execute the most appropriate processing mode in accordance with an operation status to thereby efficiently and highly accurately determine an optimal value of a development bias which is one density controlling factor.
    Type: Grant
    Filed: November 9, 2001
    Date of Patent: July 2, 2002
    Assignee: Seiko Epson Corporation
    Inventors: Hiroshi Nakazato, Yoshio Nakazawa, Takashi Hama