Loading patent…
AssigneeHewlett-Packard Development Company, L.P.
InventorsXavier Bruch, Xavier Girones, Antoni Murcia, Christopher Taylor, Ramon Vega
Estimating the term…
A method of servicing a pen comprising a printhead, having a plurality of nozzles, mounted in an inkjet printing device, comprising a servicing area and a drop detector comprising the following steps performing a drop detection on the printhead to check if any of the nozzles of the printhead are malfunctioning; storing the result of the more recent drop detection operation, together with the results of the previous drop detections to keep a history of the health status of each nozzle; deciding whether or not to execute a recovery service in the servicing area to attempt to recover the current malfunctioning nozzles, based on the more recent status of the nozzles and on the history of the health status of the nozzles.
A method of servicing a pen comprising a printhead, having a plurality of nozzles, mounted in an inkjet printing device for printing plots, comprising a servicing area and a drop detector comprising the following steps
A method as claimed in any preceding claims wherein the recovery service comprises a sequence of a plurality of different servicing procedures, at least one of said plurality of different servicing procedures is repeatable, based on its recovery effectiveness.
A method as claimed in any of the preceding claims wherein the history of the health status comprises a sequence of historical values each value corresponding to the total number of malfunctioning nozzles as detected in a previous usable drop detection, and the recovery service is executed if the total number of malfunctioning nozzles is bigger than a fifth predetermined threshold, the total number of malfunctioning nozzles being selected from said sequence of historical values.
A method of alleviating problems caused by malfunctioning nozzles of a printhead comprised in a pen mounted in an inkjet printing device, containing a drop detector, the method comprising the following steps
An inkjet printing device, for placing droplets of ink on a medium, comprising
Dependencies are inferred from the claim text.
Drawings are temporarily unavailable. Open the PDF at USPTO
From the US filing history. Foreign family members aren’t listed.
Backward citations are indexed for grants only.
Prevention or detection of nozzle clogging, e.g. cleaning, capping or moistening for nozzles: detection means therefor, e.g. for nozzle clogging
Typewriters
Term end not estimated
The present invention relates to inkjet printing devices, and particularly although not exclusively to a method and apparatus for servicing a pen when mounted in a printing device.
Inkjet printing mechanisms may be used in a variety of different printing devices, such as plotters, facsimile machines and inkjet printers, collectively called in the following as printers, to print images using a colorant, referred to generally herein as “ink.” These inkjet printing mechanisms use inkjet cartridges, often called “pens,” to shoot drops of ink onto a page or sheet of print media. Some inkjet print mechanisms carry an ink cartridge with an entire supply of ink back and forth across the sheet. Other inikjet print mechanisms, known as “off-axis” systems, propel only a small ink supply with the printhead carriage across the printzone, and store the main ink supply in a stationary reservoir, which is located “off-axis” from the path of printhead travel. Typically, a flexible conduit or tubing is used to convey the ink from the off-axis main reservoir to the printhead cartridge. In multi-color cartridges, several printheads and reservoirs are combined into a single unit, with each reservoir/printhead combination for a given color also being referred to herein as a “pen.”
Each pen has a printhead that includes very small nozzles through which the ink drops are fired. The particular ink ejection mechanism within the printhead may take on a variety of different forms known to those skilled in the art, such as those using piezo-electric or thermal printhead technology. For instance, two earlier thermal ink ejection mechanisms are shown in U.S. Pat. Nos. 5,278,584 and 4,683,481, both assigned to the present assignee, Hewlett-Packard Company. In a thermal system, a barrier layer containing ink channels and vaporization chambers is located between a nozzle orifice plate and a substrate layer. This substrate layer typically contains linear arrays of heater elements, such as resistors, which are energized to heat ink within the vaporization chambers. Upon heating, an ink droplet is ejected from a nozzle associated with the energized resistor.
For a better understanding of the invention and to show how the same may be carried into effect, there will now be described by way of example only, specific embodiments, methods and processes according to the present invention with reference to the accompanying drawings in which:
FIG. 1 is a perspective view of one form of an inkjet printing mechanism, here an inkjet printer, including one form of an inkjet printhead cleaner service station system of the present invention, shown here to service a set of inkjet printheads;
FIG. 2 is an enlarged perspective view of the service station system of FIG. 1;
There will now be described by way of example the best mode contemplated by the inventors for carrying out the invention. In the following description numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent however, to one skilled in the art, that the present invention may be practiced without limitation to these specific details. In other instances, well known methods and structures have not been described in detail so as not to unnecessarily obscure the present invention.
Specific methods according to the present invention described herein are aimed at printer devices having a printhead comprising a plurality of nozzles, each nozzle of the plurality of nozzles being configured to spray a stream of droplets of ink. Printing to a print medium is performed by moving the printhead into mutually orthogonal directions in between print operations as described herein before. However, it will be understood by those skilled in the art that general methods disclosed and identified in the claims herein, are not limited to printer devices having a plurality of nozzles or printer devices with moving print heads.
FIG. 1 illustrates a first embodiment of an inkjet printing mechanism, here shown as an inkjet printer 20, constructed in accordance with the present invention, which may be used for printing conventional engineering and architectural drawings, as well as high quality poster-sized images, and the like, in an industrial, office, home or other environment. A variety of inkjet printing mechanisms are commercially available. For instance, some of the printing mechanisms that may embody the present invention include desk top printers, portable printing units, copiers, cameras, video printers, and facsimile machines, to name a few. For convenience the concepts of the present invention are illustrated in the environment of an inkjet printer 20.