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US 6,554,380 B2Granted
Method for detecting a liquid used for discharge, and a liquid discharging device
AssigneeCanon Kabushiki Kaisha
InventorsJiro Moriyama, Yoshio Uchikata
Life of this patent
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AssigneeCanon Kabushiki Kaisha
InventorsJiro Moriyama, Yoshio Uchikata
Estimating the term…
A liquid detection method and a liquid discharging device to detect whether or not a liquid can be supplied in a state in which a liquid channel from a tank for accommodating the liquid to each discharging port of a recording head is not disconnected by a bubble. A detection-signal input terminal is provided at a position where it contacts the liquid. A detection terminal is provided at a position where it does not electrically contact the liquid and is isolated from the liquid within the tank via a lower wall of the tank, made of an insulating plastic material, and the air. An electrical signal is input from a recording apparatus to the detection-signal input terminal via a connection terminal. The input electrical signal is transmitted through the ink within the recording head, the liquid channel within a joint, and the liquid within the tank. The detection terminal, comprising a conductive metal plate provided at a position corresponding to the entire lower surface of the tank, detects the waveform of a voltage. By comparing the detected voltage with a predetermined threshold, it is determined whether or not the liquid can be normally supplied.
A liquid detection method in a configuration including a tank for accommodating a liquid, and a recording head for discharging the liquid supplied from the tank via a liquid channel from discharging ports onto a recording medium, said method comprising the steps of:
A liquid discharging device including a tank for accommodating a liquid, and a recording head for discharging the liquid supplied from said tank via a liquid channel from discharging ports onto a recording medium, said device comprising:
Dependencies are inferred from the claim text.
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From the US filing history. Foreign family members aren’t listed.
Ink supply systems ; Circuit parts therefor: ink level or ink residue control
Ink level or ink residue control: measuring electrical impedance for ink level indication
Typewriters
Term ended 2 Oct 2017 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
1. Field of the Invention
This invention relates to a liquid detection method and a liquid discharging device in which, in an ink-jet recording head used in a liquid discharging apparatus for recording (printing) characters and/or images by discharging ink droplets, a mechanism for detecting the remaining amount of ink within an ink tank for supplying ink to be discharged, and for determining continuity of ink from the ink tank to a portion near a discharging port, i.e., “disconnection of ink”, is provided.
Recording (printing) is not necessarily performed on paper, but ink may be provided onto a recording medium such as cloth, string, film material, leather, metal, glass or the like.
FIG. 1 is a diagram illustrating the configuration of a recording head according to a first embodiment of the present invention;
FIGS. 2A and 2B are enlarged cross-sectional views of the recording head shown in FIG. 1;
FIG. 3 is a perspective view illustrating an ink-jet recording apparatus according to the first embodiment;
Preferred embodiments of the present invention will now be described in detail with reference to the drawings.
First Embodiment
FIG. 1 is a diagram illustrating the configuration of a recording head in an ink-jet printer, serving as a recording apparatus, according to a first embodiment of the present invention. In FIG. 1, a recording head 1 and ink tanks 20 perform scanning in a direction perpendicular to the plane of FIG. 1, to form characters and/or images.