Patents by Inventor Kohta AKIYAMA

Kohta AKIYAMA 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: 20220143975
    Abstract: A liquid discharge apparatus is configure to drive nozzles with drive waveforms with which timing of discharge pulses fall within a range where a condition |A?C|<|B?D| is satisfied, where “A” is a discharge velocity of a droplet having a first size when drive units are driven to discharge a droplet having the first size, “B” is a discharge velocity of a droplet having a second size larger than the first size when drive units are driven to discharge a droplet having the second size, “C” is a discharge velocity of a droplet having the first size when drive units are driven to discharge droplets having the first size and the second size, and “D” is a discharge velocity of a droplet having the second size when drive units are driven to discharge droplets having the second size and the first size.
    Type: Application
    Filed: October 26, 2021
    Publication date: May 12, 2022
    Applicant: Ricoh Company, Ltd.
    Inventor: Kohta Akiyama
  • Publication number: 20220032614
    Abstract: A liquid discharge device and a method of discharging liquid. The liquid discharge device includes a head driver to drive an actuator element to generate force to discharge an ink droplet from a head onto an object to be conveyed, the object to be conveyed moving relative to the head, and a discharge controller. The discharge controller and the method includes computing a first drive cycle according to an amount of relative movement of the object moving relative to a head, adjusting the first drive cycle to a value within a second cycle range different from a first cycle range in which an ink droplet is abnormally discharged from the head, obtaining a second drive cycle as a result of adjustment performed on the first drive cycle, every time the second drive cycle passes one or more times, and adjusting the first drive cycle.
    Type: Application
    Filed: July 16, 2021
    Publication date: February 3, 2022
    Applicant: Ricoh Company, Ltd.
    Inventor: Kohta AKIYAMA
  • Patent number: 11130338
    Abstract: A liquid discharge head includes a plurality of nozzles from which a liquid is discharged in a discharge direction, a plurality of individual chambers communicating with the plurality of nozzles, respectively, a common chamber communicating with each of the plurality of individual chambers, a drive element configured to change a volume of each of the plurality of individual chambers to discharge the liquid in the plurality of individual chambers from the plurality of nozzles, and a refrigerant channel through which a refrigerant flows, the refrigerant channel facing the common chamber via a partition in the discharge direction.
    Type: Grant
    Filed: November 7, 2019
    Date of Patent: September 28, 2021
    Assignee: Ricoh Company, Ltd.
    Inventors: Ryohta Matsufuji, Kohta Akiyama, Noriyasu Takeuchi
  • Publication number: 20200290352
    Abstract: A liquid discharge head includes a nozzle plate including a plurality of nozzles from each of which a liquid is discharged, and a channel member including a plurality of pressure chambers respectively communicating with the plurality of nozzles. The channel member includes a side wall in each of the plurality of pressure chambers, the side wall is perpendicularly bonded to the nozzle plate, a thickness of the side wall increases toward the nozzle plate, and the nozzle plate includes a flat surface in a periphery of each of the plurality of nozzles on a surface of the nozzle plate facing one of the plurality of pressure chambers.
    Type: Application
    Filed: February 21, 2020
    Publication date: September 17, 2020
    Inventors: Kohta Akiyama, Yusuke Nonoyama, Ryohta Matsufuji
  • Patent number: 10730288
    Abstract: A liquid discharge head includes a plurality of individual chambers communicating with a plurality of nozzles that discharges a liquid, a common chamber formed by a frame and communicating with the plurality of individual chambers, a temperature detector to detect temperature of the liquid, and a temperature controller connected to the temperature detector, to heat or cool the liquid in the common chamber based on readings from the temperature detector. The temperature detector is disposed opposite the common chamber across the plurality of individual chambers in a direction perpendicular to a direction of liquid discharge from the plurality of nozzles.
    Type: Grant
    Filed: October 2, 2018
    Date of Patent: August 4, 2020
    Assignee: Ricoh Company, Ltd.
    Inventors: Kohta Akiyama, Noriyasu Takeuchi
  • Publication number: 20200171828
    Abstract: A liquid discharge head includes a plurality of nozzles from which a liquid is discharged in a discharge direction, a plurality of individual chambers communicating with the plurality of nozzles, respectively, a common chamber communicating with each of the plurality of individual chambers, a drive element configured to change a volume of each of the plurality of individual chambers to discharge the liquid in the plurality of individual chambers from the plurality of nozzles, and a refrigerant channel through which a refrigerant flows, the refrigerant channel facing the common chamber via a partition in the discharge direction.
    Type: Application
    Filed: November 7, 2019
    Publication date: June 4, 2020
    Applicant: Ricoh Company, Ltd.
    Inventors: Ryohta Matsufuji, Kohta Akiyama, Noriyasu Takeuchi
  • Publication number: 20190217607
    Abstract: A liquid discharge head includes a plurality of individual chambers communicating with a plurality of nozzles that discharges a liquid, a common chamber formed by a frame and communicating with the plurality of individual chambers, a temperature detector to detect temperature of the liquid, and a temperature controller connected to the temperature detector, to heat or cool the liquid in the common chamber based on readings from the temperature detector. The temperature detector is disposed opposite the common chamber across the plurality of individual chambers in a direction perpendicular to a direction of liquid discharge from the plurality of nozzles.
    Type: Application
    Filed: October 2, 2018
    Publication date: July 18, 2019
    Inventors: Kohta AKIYAMA, Noriyasu Takeuchi
  • Patent number: 10166767
    Abstract: A drive waveform generating device includes a plurality of waveform generating units each configured to generate and output a drive waveform to a corresponding one of a plurality of pressure generators that are provided corresponding to a plurality of nozzles of a liquid discharge head. Each of the plurality of waveform generating units includes a detector and a waveform generator. The detector is configured to detect data associated with a type of the drive waveform to be applied to at least one pressure generator of the plurality of pressure generators corresponding to at least one adjacent nozzle to a target nozzle. The waveform generator is configured to change a waveform shape of the drive waveform to be applied to one pressure generator of the plurality of pressure generators corresponding to the target nozzle in accordance with the data detected by the detector.
    Type: Grant
    Filed: May 2, 2017
    Date of Patent: January 1, 2019
    Assignee: RICOH COMPANY, LTD.
    Inventor: Kohta Akiyama
  • Publication number: 20170326874
    Abstract: A drive waveform generating device includes a plurality of waveform generating units each configured to generate and output a drive waveform to a corresponding one of a plurality of pressure generators that are provided corresponding to a plurality of nozzles of a liquid discharge head. Each of the plurality of waveform generating units includes a detector and a waveform generator. The detector is configured to detect data associated with a type of the drive waveform to be applied to at least one pressure generator of the plurality of pressure generators corresponding to at least one adjacent nozzle to a target nozzle. The waveform generator is configured to change a waveform shape of the drive waveform to be applied to one pressure generator of the plurality of pressure generators corresponding to the target nozzle in accordance with the data detected by the detector.
    Type: Application
    Filed: May 2, 2017
    Publication date: November 16, 2017
    Inventor: Kohta AKIYAMA
  • Patent number: 9757942
    Abstract: An inkjet recording method performed by inkjet recording device including nozzle plate with nozzle to eject droplets of ink; recording head including liquid chamber with which the nozzle is in communication, and pressure-generating unit configured to generate pressure in the liquid chamber; and signal-generating unit configured to generate signal applied to the pressure-generating unit, and allowing the droplets of the ink to eject by the pressure generated by the pressure-generating unit according to the signal, wherein the ink has static surface tension of 18.0 mN/m to 27.0 mN/m at 25° C., the ink has receding contact angle on the nozzle plate of less than 50°, the signal has two-step pull pulse for pulling the ink into the nozzle in two-step manner within one printing unit cycle, and the method includes pulling the ink located in proximity to nozzle outlet into the nozzle of the two-step pull pulse, to form meniscus at predetermined position.
    Type: Grant
    Filed: November 12, 2015
    Date of Patent: September 12, 2017
    Assignee: Ricoh Company, Ltd.
    Inventors: Kiminori Masuda, Akiko Bannai, Takashi Tamai, Naoko Kitaoka, Kohta Akiyama
  • Publication number: 20160144620
    Abstract: An inkjet recording method performed by inkjet recording device including nozzle plate with nozzle to eject droplets of ink; recording head including liquid chamber with which the nozzle is in communication, and pressure-generating unit configured to generate pressure in the liquid chamber; and signal-generating unit configured to generate signal applied to the pressure-generating unit, and allowing the droplets of the ink to eject by the pressure generated by the pressure-generating unit according to the signal, wherein the ink has static surface tension of 18.0 mN/m to 27.0 mN/m at 25° C., the ink has receding contact angle on the nozzle plate of less than 50°, the signal has two-step pull pulse for pulling the ink into the nozzle in two-step manner within one printing unit cycle, and the method includes pulling the ink located in proximity to nozzle outlet into the nozzle of the two-step pull pulse, to form meniscus at predetermined position.
    Type: Application
    Filed: November 12, 2015
    Publication date: May 26, 2016
    Inventors: Kiminori MASUDA, Akiko Bannai, Takashi Tamai, Naoko Kitaoka, Kohta Akiyama
  • Patent number: 9162447
    Abstract: An image forming apparatus includes: and a unit that electrically shuts off a pressure generating unit corresponding to a nozzle ejecting no droplet, from a drive waveform generating unit for a period of a time Tb satisfying a relation Tb?T2, and that applies, at a time after the shutoff, a voltage of a potential V1 to the pressure generating unit, where a potential serving as a reference for the drive waveform is denoted as V1, a minimum potential difference from the potential V1 required to displace a pressure generating unit to vibrate a meniscus with ejecting no liquid droplet from a nozzle is denoted as ?V2, a time required for a potential to drop by the potential difference ?V2 due to self-discharge after a pressure generating unit is charged to a predetermined potential is denoted as T2.
    Type: Grant
    Filed: February 14, 2013
    Date of Patent: October 20, 2015
    Assignee: Ricoh Company, Limited
    Inventor: Kohta Akiyama
  • Patent number: 9010917
    Abstract: An inkjet recording method includes using ink for inkjet recording containing a hydrodispersible colorant, a surfactant, water, and an organic solvent containing a polyol, an amide compound represented by the following Formula I, and an oxetane compound represented by the following Formula II; using a recording medium having a particular transfer amount of highly deionized water as measured by an automatic scanning absorptometer; and forming an image on the recording medium with the ink, wherein the ink has a particular wettability, where ?? represents dynamic surface tension as measured by maximum bubble pressure technique and ? represents a contact angle, where R represents an alkyl group, where R3 represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a cyclohexyl group, and a phenyl group.
    Type: Grant
    Filed: May 14, 2013
    Date of Patent: April 21, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroshi Gotou, Hidetoshi Fujii, Kohta Akiyama
  • Patent number: 8944560
    Abstract: An image forming apparatus includes: a recording head including multiple nozzles and multiple piezoelectric elements that generate pressure for causing droplets to be ejected from the nozzles; a driving-waveform generating unit that generates a driving waveform to be applied to the piezoelectric elements; first switching devices each disposed between the driving-waveform generating unit and respective one of the piezoelectric elements; second switching devices each disposed between a predetermined voltage and respective one of the piezoelectric elements; and a slight-vibration control unit. The slight-vibration control unit causes slight vibrations to be applied to a non-ejection nozzle by placing the second switch device for the non-ejection nozzle in a conduction state, and, when a predetermined period of time has elapsed after shift to the conduction state, placing the second switch device in a non-conduction state and the first switch device for the non-ejection nozzle in a conduction state.
    Type: Grant
    Filed: March 13, 2013
    Date of Patent: February 3, 2015
    Assignee: Ricoh Company, Limited
    Inventors: Sumiaki Aoki, Kohta Akiyama
  • Publication number: 20130323474
    Abstract: An inkjet recording method includes using ink for inkjet recording containing a hydrodispersible colorant, a surfactant, water, and an organic solvent containing a polyol, an amide compound represented by the following Formula I, and an oxetane compound represented by the following Formula II; using a recording medium having a particular transfer amount of highly deionized water as measured by an automatic scanning absorptometer; and forming an image on the recording medium with the ink, wherein the ink has a particular wettability, where ?? represents dynamic surface tension as measured by maximum bubble pressure technique and ? represents a contact angle, where R represents an alkyl group, where R3 represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a cyclohexyl group, and a phenyl group.
    Type: Application
    Filed: May 14, 2013
    Publication date: December 5, 2013
    Inventors: Hiroshi GOTOU, Hidetoshi Fujii, Kohta Akiyama
  • Publication number: 20130241986
    Abstract: An image forming apparatus includes: a recording head including multiple nozzles and multiple piezoelectric elements that generate pressure for causing droplets to be ejected from the nozzles; a driving-waveform generating unit that generates a driving waveform to be applied to the piezoelectric elements; first switching devices each disposed between the driving-waveform generating unit and respective one of the piezoelectric elements; second switching devices each disposed between a predetermined voltage and respective one of the piezoelectric elements; and a slight-vibration control unit. The slight-vibration control unit causes slight vibrations to be applied to a non-ejection nozzle by placing the second switch device for the non-ejection nozzle in a conduction state, and, when a predetermined period of time has elapsed after shift to the conduction state, placing the second switch device in a non-conduction state and the first switch device for the non-ejection nozzle in a conduction state.
    Type: Application
    Filed: March 13, 2013
    Publication date: September 19, 2013
    Applicant: Ricoh Company, Limited
    Inventors: Sumiaki AOKI, Kohta AKIYAMA
  • Publication number: 20130215173
    Abstract: An image forming apparatus includes: and a unit that electrically shuts off a pressure generating unit corresponding to a nozzle ejecting no droplet, from a drive waveform generating unit for a period of a time Tb satisfying a relation Tb?T2, and that applies, at a time after the shutoff, a voltage of a potential V1 to the pressure generating unit, where a potential serving as a reference for the drive waveform is denoted as V1, a minimum potential difference from the potential V1 required to displace a pressure generating unit to vibrate a meniscus with ejecting no liquid droplet from a nozzle is denoted as ?V2, a time required for a potential to drop by the potential difference ?V2 due to self-discharge after a pressure generating unit is charged to a predetermined potential is denoted as T2.
    Type: Application
    Filed: February 14, 2013
    Publication date: August 22, 2013
    Inventor: Kohta AKIYAMA