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US 6,607,262 B2Granted
Reserving ink for printer servicing purposes
AssigneeHewlett-Packard Company
InventorsRonald G. Paul, Rory A. Heim
Life of this patent
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AssigneeHewlett-Packard Company
InventorsRonald G. Paul, Rory A. Heim
Estimating the term…
An inkjet printing system and method that enables printing to continue after an ink supply has been depleted without damaging the printhead associated with the depleted ink supply. The method detects whether less than a predetermined reserve amount of ink remains in a depleted ink supply and, if so, then ink drops will be ejected from that depleted ink supply only during servicing operations. Since ink drops from non-depleted ink supplies will still be ejected during both printing operations and servicing operations, printing can continue, though possibly with reduced image quality. This is particularly advantageous in printing systems that include fax capability, since fax messages that cannot be printed may be lost.
A method of printing with an inkjet printing system having a plurality of ink supplies, comprising:
A method of printing with an inkjet printing system having a plurality of ink supplies, comprising:
A method for extending the useful life of a multiple-reservoir ink cartridge for inkjet printing system, comprising:
An inkjet printing system, comprising:
An inkjet printing system, comprising:
An inkjet printing system, comprising:
An inkjet printing system, comprising:
An inkjet printing system, comprising:
An inkjet printing system, comprising:
A method for extending the useful life of a multiple-reservoir ink cartridge for an inkjet printing system, 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.
Ink supply systems ; Circuit parts therefor: ink level or ink residue control
Cleaning of print head nozzles: by driving a fluid through the nozzles to the outside thereof, e.g. by applying pressure to the inside or vacuum…
Ink level or ink residue control: using ink level as input for printer mode selection or for prediction of remaining printing capacity
Typewriters
Term ended 6 Jul 2021 (estimated)
The present invention relates generally to inkjet printing, and pertains more particularly to operation of an inkjet printing system as an ink supply nears exhaustion.
Hardcopy output devices, such as printers and fax machines, frequently make use of an inkjet printhead mounted within a carriage that is moved relative to a print medium, such as paper. Hardcopy devices of this sort are described by W. J. Lloyd and H. T. Taub in “Ink Jet Devices” ,Chapter 13 of Output Hardcopy Devices (Ed. R. C. Durbeck and S. Sherr, San Diego: Academic Press, 1988). As the printhead is moved relative to the print medium, a control system selectively activates individual printing elements in the printhead to deposit or eject ink droplets onto the print medium to form printed output that may include images and text. Ink is provided to the printhead from a supply of ink. An inkjet hardcopy device typically uses several different color ink supplies, each with an associated printhead, to produce color print output. A typical set of color inks includes cyan, magenta, yellow, and black inks. During printing, drops of different ones of these inks may be deposited in the same or adjacent locations to form a range of colors. Further information as to the basics of inkjet printing technology are further disclosed in various articles in several editions of the Hewlett-Packard Journal[Vol. 36, No. 5 (May 1985), Vol.39, No. 4 (August 1988), Vol. 39, No. 5 (October 1988), Vol. 43, No. 4 (August 1992), Vol. 43, No. 6 (December 1992) and Vol. 45, No. 1 (February 1994)], incorporated herein by reference.
In order to ensure that the printed output is of high quality, it is critical that proper care of the printhead is taken during both operation and non-operation. If printing is attempted after the supply of ink has run out, the printing elements can be damaged from the entry of air into the printhead such that they will no longer operate properly when a new ink supply is provided. Similarly, care must be taken to ensure that moisture in the nozzles of the printing elements not dry out. When the printhead is not in operation, the nozzles are typically mechanically capped to retain moisture. During operation, when the nozzles are not capped but instead are exposed to air, the printing elements are periodically serviced, typically by ejecting drops of the ink into a spittoon, in order to keep the nozzles moist.
The above-mentioned features of the present invention and the manner of attaining them, and the invention itself, will be best understood by reference to the following detailed description of the preferred embodiment of the invention, taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is a perspective view of a printing system according to the present invention;
FIG. 2 is a schematic diagram of a portion of the printing system of FIG. 1 illustrating the elements of a scanning carriage and a service station;
Referring now to the drawings, there is illustrated a printing system and method constructed in accordance with the present invention which detect the impending depletion of an ink supply and subsequently modify printing behavior so as to allow the printing system to continue printing for an extended period of time without replacing the ink supply and without damage to any of the printing elements of the printing system. A preferred embodiment of such a printing system includes at least one replaceable ink cartridge. Each ink cartridge contains at least one ink reservoir which holds a supply of an ink. A printhead for ejecting drops of the ink is fluidically coupled to an individual ink reservoir. An ink level detection arrangement in the printing system determines whether the amount of the ink in any reservoir is less than a predetermined reserve level. If so, a drop ejection arrangement inhibits drop ejection from the printhead which is coupled to that ink reservoir during printing operations, while still enabling drop ejection from that printhead during servicing operations. The use of the reserve amount of ink solely to perform servicing operations allows the printing system to continue printing with other ink supplies that have not been depleted, while using the reserve amount of ink in the depleted ink reservoir to prevent air from entering the printhead, and to keep the nozzles and other portions of the printing elements from drying out while the printheads are decapped.
Considering a preferred embodiment of the printing system 10 in further detail, and with reference to FIG. 1, the printing system 10 includes at least one replaceable ink cartridge 12 that is installed in a receiving station 14. With the replaceable ink cartridge 12 properly installed into the receiving station 14, ink is provided from the replaceable ink cartridge 12 to at least one inkjet printhead 16. The inkjet printhead 16 is responsive to activation signals from a printer portion 18 to deposit ink drops on a print medium 22. As ink drops are ejected from the printhead 16, the printhead 16 is replenished with ink from an ink supply in the cartridge 12.
In one preferred embodiment, the replaceable ink cartridge 12, receiving station 14, and inkjet printhead 16 are each part of a scanning carriage 20 that is moved relative to a print medium 22 during a printing operation to accomplish printing on the medium 22. The printer portion 18 includes a media tray 24 for receiving the print media 22. As the print medium 22 is stepped through a print zone, the scanning carriage 20 moves the printhead 16 relative to the print medium 22. The printer portion 18 selectively activates the printhead 16 to deposit ink on the print medium 22 to perform printing.