Ink drop writing apparatus
AssigneeHitachi, Ltd.
InventorsTakahiro Yamada, Tetsuo Doi
Life of this patent
Estimating the term…
Abstract
In an apparatus of the type wherein ink under pressure is applied to a nozzle which is vibrated so that the ink emitted from the nozzle thereafter breaks up into ink drops which are charged in a charging tunnel in response to a video signal, means are provided, in accordance with this invention, for compensating the amount of charge on each ink drop or the strength of the deflecting field action on the ink drop, on the basis of information from a detecting means which detects the amount of deflection of one or more calibrating drops periodically so that the amount of deflection of the drop of writing fluid for a given charge may be held to a predetermined value.
Claims13
In an ink drop writing apparatus including a high frequency voltage source, nozzle means supplied with ink under pressure for generating an ink stream directed toward a recording medium, electro-mechanical converter means connected to said high frequency voltage source for vibrating said nozzle means to cause the ink stream to break up into a stream of regularly spaced ink drops, means for generating recording signals, means for charging the drops in accordance with the charge therein, means responsive to the recording signals for applying a signal voltage to said charging means, and means for deflecting the drops in accordance with the charge thereon, the improvement comprising
- a. calibrating means for controlling said charging means to apply a predetermined charge to selected drops;
- b. means for detecting the amount of deflection of the selected drops and the deviation of the measured detection from a standard value;
- and
- c. correcting means responsive to said detecting means for regulating said charging means to compensate the amount of charge applied to the selected drops to eliminate said deviation, said correcting means including signal voltage adjusting means for regulating the magnitude of said signal voltage.
In an ink drop writing apparatus including a first high frequency voltage source, nozzle means supplied with ink under pressure for generating an ink stream directed toward a recording medium, electro-mechanical converter means connected to said first high frequency voltage source for vibrating said nozzle means to cause the ink stream to break up into a stream of regularly spaced ink drops, means for generating recording signals, circuit means for generating predetermined calibrating signals, means for charging the drops in accordance with the charge therein, charging voltage generating means for charging said charging means in accordance with said recording signals or said calibrating signals, and means for deflecting the drops in accordance with the charge therein, the improvement comprising
- a. calibrating means responsive to said circuit means for controlling said charging means to apply a predetermined charge to selected drops, including means for selectively connecting said recording signal generating means or said circuit means to said charging voltage generating means with a predetermined phase;
- b. means for detecting the amount of deflection of the selected drops charged by said calibrating signals and for determining the deviation of the measured detection from a standard value;
- c. corresponding means responsive to said detecting means for regulating said charging means to compensate the amount of charge applied to the drops to eliminate said deviation, said correcting means including signal voltage adjusting means for regulating the magnitude of the recording signals and the calibrating signals applied to said charging means in accordance with the output of said detecting means.
In an ink drop writing apparatus wherein writing fluid is supplied to a nozzle which is vibrated by a transducer driving from a first high frequency power source to produce a stream of writing fluid which separates into individual drops directed toward a recording medium and including means for generating recording signals, means for charging the drops in accordance with said recording signals including a charging electrode and means responsive to said recording signals for applying a signal voltage to said charging electrode and means for deflecting the drops in accordance with the charge therein, the improvement comprising
- calibrating means for controlling said charging means to apply to selected drops a predetermined charge,
- deflection detecting means for detecting the amount of deflection of said selected drops, and
- correcting means responsive to said detecting means for regulating the magnitude of the signal voltage which is applied to said charging electrode to compensate the amount of charge applied to the drops of writing fluid so that said drops will be deflected by a predetermined amount for a given charge thereon including an UP/DOWN counter responsive to the output of said detecting means, a second high frequency source for driving said UP/DOWN counter, a digital/analog converter connected to the output of said UP/DOWN counter, and signal voltage adjusting means responsive to said calibrating means and said digital/analog counter for controlling the level of the voltage applied to said charging means.
In an ink drop writing apparatus wherein writing fluid is supplied to a nozzle which is vibrated by a transducer driven from a first high frequency power source to produce a stream of writing fluid which separates into individual drops directed toward a recording medium and including means for generating recording signals, means for charging the drops in accordance with said recording signals and deflection means for generating an electrostatic field to deflect the drops in accordance with the charge therein, the improvement comprising
- calibrating means for controlling said charging means to apply to selected drops a predetermined charge,
- deflection detecting means for detecting the amount of deflection of said selected drops, and
- correcting signal generating means responsive to said detecting means for regulating said deflection means to adjust the strength of said electrostatic field so that said drops will be deflected by a predetermined amount for a given charge thereon including an UP/DOWN counter responsive to the output of said detecting means, a second high frequency source for driving said UP/DOWN counter, a digital/analog converter connected to the output of said UP/DOWN counter, and signal voltage adjusting means responsive to the output of said digital/analog converter for regulating said deflection means.
Dependencies are inferred from the claim text.