US 6,631,970 B2Granted

Ink jet recording apparatus and ink jet print head

AssigneeCanon Kabushiki Kaisha

InventorsTomonori Sato, Shinji Takagi, Kentaro Yano, Tetsuhito Ikeda

Life of this patent

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Abstract

An ink jet recording apparatus is provided which can detect ink in a print head highly precisely with a simple construction. The apparatus includes: a detection electrode to detect, through the ink on the ink jet print head board, a voltage change between print elements and drive elements which is produced as the print elements are driven; a periodical driver to drive the print elements at a predetermined drive frequency; a voltage detector to periodically detect an output voltage of the detection electrode at a timing corresponding to the drive frequency; and a state check device to check an ink ejection state of the ink jet print head according to a result of the detection by the voltage detector.

Claims23

Dependent claims

An ink jet recording apparatus having an ink jet print head board mounted on an ink jet print head, the ink jet print head ejecting a conductive ink from ejection ports to perform printing, the ink jet print head board comprising:

print elements for supplying energy to eject the ink;
drive elements for driving the print elements;
an insulating protective film formed to cover wires connecting the print elements and the drive elements;
a detection electrode capable of detecting, through the ink on the ink jet print head board, an electric potential between signal sources and the drive elements, said signal sources being for signals generated according to the driving of the print elements, and said signals being generated through said insulating protective film;
periodical drive means for driving the print elements at a predetermined drive frequency;
voltage detection means for periodically detecting an output voltage of the detection electrode at a timing corresponding to the drive frequency;
and
state check means for checking a state of the ink jet print head according to a result of the detection by the voltage detection means.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 09/854,680Filed 15 May 2001
Priority: JP 2000-14385216 May 2000
Published: US 2002/0021315 A121 Feb 2002
Granted: 14 Oct 2003
Term ends: Not estimatedThe source records don’t support an estimate.

Classification7 codes

B41J 2/0451
Control methods or devices therefor, e.g. driver circuits, control circuits: for detecting failure, e.g. clogging, malfunctioning actuator
B41J 2/04573
Control methods or devices therefor, e.g. driver circuits, control circuits: timing; Delays
B41J 2/0458
Control methods or devices therefor, e.g. driver circuits, control circuits: controlling heads based on heating elements forming bubbles
B41J 2/04588
Control methods or devices therefor, e.g. driver circuits, control circuits: using a specific waveform