Patents by Inventor Hermanus M. A. Wijshoff

Hermanus M. A. Wijshoff 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: 9744763
    Abstract: In a method for jetting a droplet of an electrically conductive fluid, a Lorentz force is generated in the electrically conductive fluid. The Lorentz force is directed into an actuation direction. The actuation direction is a direction opposite to the droplet ejection direction. A jetting device is provided for printing a droplet of an electrically conductive fluid.
    Type: Grant
    Filed: December 22, 2015
    Date of Patent: August 29, 2017
    Assignee: OCÉ-TECHNOLOGIES B.V.
    Inventors: Sandor H. G. Joppen, Hermanus M. A. Wijshoff
  • Publication number: 20160107441
    Abstract: In a method for jetting a droplet of an electrically conductive fluid, a Lorentz force is generated in the electrically conductive fluid. The Lorentz force is directed into an actuation direction. The actuation direction is a direction opposite to the droplet ejection direction. A jetting device is provided for printing a droplet of an electrically conductive fluid.
    Type: Application
    Filed: December 22, 2015
    Publication date: April 21, 2016
    Applicant: OCÉ-TECHNOLOGIES B.V.
    Inventors: Sandor H.G. JOPPEN, Hermanus M.A. WIJSHOFF
  • Patent number: 8678564
    Abstract: In an inkjet print head an actuation chamber substantially extends in a first direction and the actuation chamber is associated with a piezo actuator arranged to generate a pressure wave in the actuation chamber. The pressure wave propagates in said first direction. A nozzle is associated with the actuation chamber such that a droplet may be expelled through the nozzle upon generation of the pressure wave in the actuation chamber. A reservoir is in fluid communication with the actuation chamber via an inlet and an outlet of the actuation chamber. A pump means is provided for pumping ink from the reservoir, via the inlet, through the actuation chamber, via the outlet back into said reservoir. The print head is provided with a means for reflecting the pressure wave at the outlet of the actuation chamber for enabling to generate a sufficient pressure at the nozzle for expelling the droplet.
    Type: Grant
    Filed: March 14, 2013
    Date of Patent: March 25, 2014
    Assignee: Oce-Technologies B.V.
    Inventors: Hermanus M. A. Wijshoff, Peter Klein Meuleman
  • Patent number: 7703893
    Abstract: An inkjet system including a printhead with an ink-fillable chamber operatively connected to a piezoelectric actuator and provided with a nozzle for the ejection of ink drops in response to the energization of the actuator, which actuator is connected to a measuring circuit for measuring an electrical signal generated by the actuator in response to the deformation thereof, wherein the system is configured such that a natural frequency of said system corresponds substantially to a natural frequency of a disturbance in the system.
    Type: Grant
    Filed: June 22, 2005
    Date of Patent: April 27, 2010
    Assignee: Océ-Technologies B.V.
    Inventors: Mark A. Gröninger, Marcus J. Van Den Berg, Hermanus M. A. Wijshoff
  • Patent number: 7562969
    Abstract: A inkjet printhead containing two substantially closed ink chambers separated by a wall, each of the chambers having associated therewith an electro-mechanical converter, where actuation of the converter corresponding to a first chamber of said printhead will lead to a volume change in a second chamber due to cross-talk, whereby the wall is deformable in such a way that it deforms by actuation and as such simultaneously generates a second volume change in the same chamber, either volume change being, in essence, the same size but opposite to the other.
    Type: Grant
    Filed: June 5, 2006
    Date of Patent: July 21, 2009
    Assignee: Oce Technologies B.V.
    Inventor: Hermanus M. A. Wijshoff
  • Patent number: 7481517
    Abstract: An inkjet printer for jetting ink that is substantially free of solvent, the printer containing a printhead having an ink chamber with an ink inlet and an ink outlet, an ink supply reservoir in fluid connection with the chamber via the ink inlet, an electromechanical transducer in operative connection with the ink chamber for generating pressure waves herein, and a heater for substantially uniformly heating the ink in the ink chamber, wherein the ink inlet includes a constricting element such that the pressure drop over the constricting element in the direction from the reservoir to the chamber is smaller than the pressure drop over said element in the opposite direction for the same net fluid flow and wherein the ratio of the length of the constricting element and the mean diameter of the constricting element is less than 10.
    Type: Grant
    Filed: March 30, 2006
    Date of Patent: January 27, 2009
    Assignee: Oce-Technologies B.V.
    Inventor: Hermanus M. A. Wijshoff
  • Patent number: 7398689
    Abstract: An inkjet printer containing a substantially closed ink duct and a transducer used to generate a pressure wave in the duct, wherein the transducer comprises a first part and, separate from the first part, a second part whereby, by actuation of the transducer, the first part manifests a first deformation and the second part simultaneously manifests a second deformation actually opposed to the first deformation, such that a pressure wave is generated in the ink duct.
    Type: Grant
    Filed: March 14, 2006
    Date of Patent: July 15, 2008
    Assignee: Oce-Technologies B.V.
    Inventor: Hermanus M. A. Wijshoff