Patents by Inventor Andrew Mwaniki Mulwa

Andrew Mwaniki Mulwa 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: 10268131
    Abstract: A cleaner, such as provided in a particulate material production apparatus, for cleaning a droplet ejector, which includes nozzles to eject a particulate material composition liquid as droplets, and a nozzle plate bearing the nozzles. A substantially closed cleaning space is formed outside the nozzles and the nozzle plate, and a first cleaning liquid supplying device supplies a first cleaning liquid to the cleaning space so that the nozzles and the nozzle plate are contacted with the first cleaning liquid. In addition, a vibrator vibrates the first cleaning liquid when the nozzles and the nozzle plate are contacted with the first cleaning liquid to clean the nozzles and the nozzle plate.
    Type: Grant
    Filed: November 7, 2016
    Date of Patent: April 23, 2019
    Assignee: RICOH COMPANY, LTD.
    Inventors: Yasutada Shitara, Minoru Masuda, Shinji Aoki, Yoshihiro Norikane, Andrew Mwaniki Mulwa, Masaru Ohgaki, Kiyotada Katoh, Satoshi Takahashi
  • Publication number: 20170050204
    Abstract: A cleaning method for cleaning a droplet ejector, which includes nozzles to eject a particulate material composition liquid, and a nozzle plate bearing the nozzles is provided. The cleaning method includes forming a substantially closed cleaning space outside the nozzles and the nozzle plate; supplying a cleaning liquid to the cleaning space so that the nozzles and the nozzle plate are contacted with the cleaning liquid; and vibrating the cleaning liquid when the nozzles and the nozzle plate are contacted with the cleaning liquid to clean the nozzles and the nozzle plate.
    Type: Application
    Filed: November 7, 2016
    Publication date: February 23, 2017
    Applicant: RICOH COMPANY, LTD.
    Inventors: Yasutada SHITARA, Minoru MASUDA, Shinji AOKI, Yoshihiro NORIKANE, Andrew Mwaniki MULWA, Masaru OHGAKI, Kiyotada KATOH, Satoshi TAKAHASHI
  • Patent number: 9539600
    Abstract: A cleaning method for cleaning a droplet ejector, which includes nozzles to eject a particulate material composition liquid, and a nozzle plate bearing the nozzles is provided. The cleaning method includes forming a substantially closed cleaning space outside the nozzles and the nozzle plate; supplying a cleaning liquid to the cleaning space so that the nozzles and the nozzle plate are contacted with the cleaning liquid; and vibrating the cleaning liquid when the nozzles and the nozzle plate are contacted with the cleaning liquid to clean the nozzles and the nozzle plate.
    Type: Grant
    Filed: September 18, 2013
    Date of Patent: January 10, 2017
    Assignee: RICOH COMPANY, LTD.
    Inventors: Yasutada Shitara, Minoru Masuda, Shinji Aoki, Yoshihiro Norikane, Andrew Mwaniki Mulwa, Masaru Ohgaki, Kiyotada Katoh, Satoshi Takahashi
  • Publication number: 20150108671
    Abstract: A method for producing fine particles, including: discharging a fine particle material liquid, where solid materials to be formed into fine particles are dissolved or dispersed in a solvent or are melted, from two or more discharge holes in a downward vertical direction, to thereby form liquid droplets; and solidifying the liquid droplets discharged to form fine particles, wherein in the discharging a fine particle material liquid, gas flow is supplied at angle of greater than 0° but 90° or smaller to the downward vertical direction, and wherein an initial discharge velocity of the liquid droplets discharged from the discharge hole located at an upstream side of the gas flow in a flowing direction thereof is equal to or higher than an initial discharge velocity of the liquid droplets discharged from the discharge hole located at a downstream side of the gas flow in the flowing direction thereof.
    Type: Application
    Filed: February 28, 2013
    Publication date: April 23, 2015
    Inventors: Yoshihiro Norikane, Satoshi Takahashi, Masaru Ohgaki, Andrew Mwaniki Mulwa
  • Patent number: 8919902
    Abstract: A droplet discharging device including a discharging hole to discharge droplets, a piezoelectric element that deforms with electrical charging and discharging to discharge droplets therefrom, a piezoelectric element drive circuit that drives the piezoelectric element to cause it to charge and discharge, wherein the piezoelectric element drive circuit has a control signal generating unit to generate control signals that control outputs of drive signals applied to the piezoelectric circuit and a drive signal output unit to output the drive signals applied to the piezoelectric element based on the control signals, wherein the drive signal output unit includes a first field effect transistor that operates to supply an electric current to the piezoelectric element based on the control signals when charging the piezoelectric element and a second field effect transistor that operates to discharge an electric current from the piezoelectric element based on the control signals when discharging the piezoelectric elemen
    Type: Grant
    Filed: March 6, 2013
    Date of Patent: December 30, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Shinji Aoki, Andrew Mwaniki Mulwa, Yasutada Shitara
  • Patent number: 8778239
    Abstract: A method of producing particulate, including introducing an initial liquid including a particulate component in a lower concentration than that of a liquid including a particulate component or no concentration to a projection hole of a droplet projector so as to be projected at the start of the discharging; discharging a droplet of the liquid comprising a particulate component from the projection hole; and solidifying the droplet to form a particulate.
    Type: Grant
    Filed: August 17, 2012
    Date of Patent: July 15, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Andrew Mwaniki Mulwa, Yoshihiro Norikane, Shinji Aoki, Masaru Ohgaki
  • Patent number: 8765349
    Abstract: A method of manufacturing toner is provided. In the method, toner constituents are dissolved or dispersed in an organic solvent to prepare a toner constituents liquid. The toner constituents liquid is degassed so that the toner constituents liquid includes dissolved oxygen in an amount of 3 mg/L or less. The toner constituents liquid is vibrated in a chamber having at least one nozzle to form a liquid column resonance standing wave in the toner constituents liquid. The toner constituents liquid is discharged from the nozzle disposed within an area including an antinode of the liquid column resonance standing wave to form the toner constituents liquid into liquid droplets. The liquid droplets are dried to solidify the liquid droplets into solid particles.
    Type: Grant
    Filed: July 25, 2012
    Date of Patent: July 1, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Yoshihiro Norikane, Andrew Mwaniki Mulwa, Kiyotada Katoh, Yasutada Shitara
  • Patent number: 8709697
    Abstract: A method of manufacturing a toner including supplying a fluid containing a resin and a coloring agent to a retaining member including a film having multiple discharge orifices, discharging droplets of the fluid from the multiple discharge orifices at a speed of from 2 to 4 m/s by applying a pulse voltage having a trapezoid waveform to a piezoelectric body having a surface provided substantially parallel to the film to move the surface in a direction away from the film relative to a reference position of the surface followed by holding the surface there for a predetermined time, and bringing the surface back to the reference position; and solidifying droplets of the fluid discharged from the multiple discharge orifices to form mother particles.
    Type: Grant
    Filed: July 12, 2010
    Date of Patent: April 29, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Yoshihiro Norikane, Yohichiroh Watanabe, Masaru Ohgaki, Shinji Aoki, Yasutada Shitara, Andrew Mwaniki Mulwa
  • Publication number: 20140097267
    Abstract: A cleaning method for cleaning a droplet ejector, which includes nozzles to eject a particulate material composition liquid, and a nozzle plate bearing the nozzles is provided. The cleaning method includes forming a substantially closed cleaning space outside the nozzles and the nozzle plate; supplying a cleaning liquid to the cleaning space so that the nozzles and the nozzle plate are contacted with the cleaning liquid; and vibrating the cleaning liquid when the nozzles and the nozzle plate are contacted with the cleaning liquid to clean the nozzles and the nozzle plate.
    Type: Application
    Filed: September 18, 2013
    Publication date: April 10, 2014
    Applicant: RICOH COMPANY, LTD.
    Inventors: Yasutada Shitara, Minoru Masuda, Shinji Aoki, Yoshihiro Norikane, Andrew Mwaniki Mulwa, Masaru Ohgaki, Kiyotada Katoh, Satoshi Takahashi
  • Patent number: 8574807
    Abstract: A method of manufacturing toner is provided, including discharging a toner constituents liquid from multiple nozzles to form liquid droplets and solidifying the liquid droplets into toner particles. The multiple nozzles satisfy the following formula: 2.5?p/d?7.5 wherein d represents an outlet diameter of each nozzle and p represents an interval between two nozzles.
    Type: Grant
    Filed: October 3, 2011
    Date of Patent: November 5, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Yoshihiro Norikane, Masaru Ohgaki, Andrew Mwaniki Mulwa, Yuko Sekiguchi
  • Publication number: 20130241983
    Abstract: A droplet discharging device including a discharging hole to discharge droplets, a piezoelectric element that deforms with electrical charging and discharging to discharge droplets therefrom, a piezoelectric element drive circuit that drives the piezoelectric element to cause it to charge and discharge, wherein the piezoelectric element drive circuit has a control signal generating unit to generate control signals that control outputs of drive signals applied to the piezoelectric circuit and a drive signal output unit to output the drive signals applied to the piezoelectric element based on the control signals, wherein the drive signal output unit includes a first field effect transistor that operates to supply an electric current to the piezoelectric element based on the control signals when charging the piezoelectric element and a second field effect transistor that operates to discharge an electric current from the piezoelectric element based on the control signals when discharging the piezoelectric elemen
    Type: Application
    Filed: March 6, 2013
    Publication date: September 19, 2013
    Applicant: RICOH COMPANY, LTD.
    Inventors: Shinji Aoki, Andrew Mwaniki Mulwa, Yasutada Shitara
  • Patent number: 8445172
    Abstract: A method for producing a toner, containing: ultrasonically vibrating a liquid toner composition in which a toner material containing at least a binder resin and a colorant is dissolved or dispersed in a solvent; introducing the liquid toner composition to a liquid chamber, and ejecting the liquid toner composition as droplets from an ejecting plate having a plurality of holes and disposed on one surface of the liquid chamber; and drying and solidifying the droplets so as to produce a toner, wherein the ultrasonically vibrating is performed before the introducing the liquid toner composition to the liquid chamber.
    Type: Grant
    Filed: March 5, 2010
    Date of Patent: May 21, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Yasutada Shitara, Yoshihiro Norikane, Yohichiroh Watanabe, Andrew Mwaniki Mulwa
  • Publication number: 20130069262
    Abstract: A method of producing particulate, including introducing an initial liquid including a particulate component in a lower concentration than that of a liquid including a particulate component or no concentration to a projection hole of a droplet projector so as to be projected at the start of the discharging; discharging a droplet of the liquid comprising a particulate component from the projection hole; and solidifying the droplet to form a particulate.
    Type: Application
    Filed: August 17, 2012
    Publication date: March 21, 2013
    Inventors: Andrew Mwaniki Mulwa, Yoshihiro Norikane, Shinji Aoki, Masaru Ohgaki
  • Publication number: 20130034810
    Abstract: A method of manufacturing toner is provided. In the method, toner constituents are dissolved or dispersed in an organic solvent to prepare a toner constituents liquid. The toner constituents liquid is degassed so that the toner constituents liquid includes dissolved oxygen in an amount of 3 mg/L or less. The toner constituents liquid is vibrated in a chamber having at least one nozzle to form a liquid column resonance standing wave in the toner constituents liquid. The toner constituents liquid is discharged from the nozzle disposed within an area including an antinode of the liquid column resonance standing wave to form the toner constituents liquid into liquid droplets. The liquid droplets are dried to solidify the liquid droplets into solid particles.
    Type: Application
    Filed: July 25, 2012
    Publication date: February 7, 2013
    Inventors: Yoshihiro NORIKANE, Andrew Mwaniki MULWA, Kiyotada KATOH, Yasutada SHITARA
  • Patent number: 8329373
    Abstract: A method and an apparatus for producing toner are provided. A fluid comprising a resin and a colorant is supplied to a retention member that includes a film on which multiple discharge openings are formed. The fluid which is supplied to the retention member is resonated so that liquid droplets thereof are discharged from the multiple openings. The liquid droplets which are discharged from the multiple openings are solidified to form mother particles of a toner.
    Type: Grant
    Filed: October 23, 2009
    Date of Patent: December 11, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Yoshihiro Norikane, Shinji Aoki, Masaru Ohgaki, Yohichiroh Watanabe, Takahiro Honda, Andrew Mwaniki Mulwa, Yuko Sekiguchi
  • Patent number: 8257898
    Abstract: Disclosed is a method of manufacturing a toner, wherein a liquid drop forming part including a storage part configured to store a toner composition liquid in which a toner composition including at least a resin and a coloring agent is dispersed or dissolved, a thin film on which a nozzle facing the storage part is formed, and a vibration generating part configured to vibrate the thin film via the toner composition liquid in the storage part are used, wherein plural storage chambers partitioned by a partition wall(s) are formed in the storage part and a width of each storage chamber in a direction of arrangement of the plural storage chambers and a width of each storage chamber in a direction orthogonal to the direction of arrangement of the storage chambers are formed to be one-half or less of a wavelength ? of a sonic wave generated in the storage part.
    Type: Grant
    Filed: August 26, 2009
    Date of Patent: September 4, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Yoshihiro Norikane, Shinji Aoki, Tetsuya Sonoda, Keisuke Uchida, Andrew Mwaniki Mulwa, Yuko Sekiguchi
  • Publication number: 20120094231
    Abstract: A method of manufacturing toner is provided, including discharging a toner constituents liquid from multiple nozzles to form liquid droplets and solidifying the liquid droplets into toner particles. The multiple nozzles satisfy the following formula: 2.5?p/d?7.5 wherein d represents an outlet diameter of each nozzle and p represents an interval between two nozzles.
    Type: Application
    Filed: October 3, 2011
    Publication date: April 19, 2012
    Inventors: Yoshihiro NORIKANE, Masaru Ohgaki, Andrew Mwaniki Mulwa, Yuko Sekiguchi
  • Publication number: 20110014565
    Abstract: A method of manufacturing a toner including supplying a fluid containing a resin and a coloring agent to a retaining member including a film having multiple discharge orifices, discharging droplets of the fluid from the multiple discharge orifices at a speed of from 2 to 4 m/s by applying a pulse voltage having a trapezoid waveform to a piezoelectric body having a surface provided substantially parallel to the film to move the surface in a direction away from the film relative to a reference position of the surface followed by holding the surface there for a predetermined time, and bringing the surface back to the reference position; and solidifying droplets of the fluid discharged from the multiple discharge orifices to form mother particles.
    Type: Application
    Filed: July 12, 2010
    Publication date: January 20, 2011
    Inventors: Yoshihiro NORIKANE, Yohichiroh Watanabe, Masaru Ohgaki, Shinji Aoki, Yasutada Shitara, Andrew Mwaniki Mulwa
  • Publication number: 20100227267
    Abstract: A method for producing a toner, containing: ultrasonically vibrating a liquid toner composition in which a toner material containing at least a binder resin and a colorant is dissolved or dispersed in a solvent; introducing the liquid toner composition to a liquid chamber, and ejecting the liquid toner composition as droplets from an ejecting plate having a plurality of holes and disposed on one surface of the liquid chamber; and drying and solidifying the droplets so as to produce a toner, wherein the ultrasonically vibrating is performed before the introducing the liquid toner composition to the liquid chamber.
    Type: Application
    Filed: March 5, 2010
    Publication date: September 9, 2010
    Inventors: Yasutada SHITARA, Yoshihiro Norikane, Yohichiroh Watanabe, Andrew Mwaniki Mulwa
  • Publication number: 20100104970
    Abstract: A method and an apparatus for producing toner are provided. A fluid comprising a resin and a colorant is supplied to a retention member that includes a film on which multiple discharge openings are formed. The fluid which is supplied to the retention member is resonated so that liquid droplets thereof are discharged from the multiple openings. The liquid droplets which are discharged from the multiple openings are solidified to form mother particles of a toner.
    Type: Application
    Filed: October 23, 2009
    Publication date: April 29, 2010
    Inventors: Yoshihiro Norikane, Shinji Aoki, Masaru Ohgaki, Yohichiroh Watanabe, Takahiro Honda, Andrew Mwaniki Mulwa, Yuko Sekiguchi