Patents Assigned to Carl Hellmuth Hertz
  • Method and apparatus for controlling the electrical charging of drops in an ink jet recording apparatus
    Patent number: 4839665
    Abstract: In an ink jet recording apparatus, the generation of insufficiently charged or discharged drops which may occur when a charge controlling signal (print pulse) is switched within a forbidden zone of the period of the drop formation process is avoided. The portion of the drop formation process period, during which the switching is permitted, is determined by detecting the charge carried by trains of drops which are produced by probe charge control signal of varying phase relative to the drop formation process.
    Type: Grant
    Filed: July 20, 1987
    Date of Patent: June 13, 1989
    Assignee: Carl Hellmuth Hertz
    Inventors: Carl H. Hertz, Bo A. Samuelsson