This patent application is assigned to
The following quote was obtained by the news editors from the background information supplied by the inventors: "
"Throughout the life cycle of these inkjet imaging devices, the image generating ability of the device requires evaluation and, if the images contain detectable errors, correction. Missing inkjets or weak inkjets exemplify printhead errors that affect ink image quality. A missing inkjet is an inkjet that does not eject an ink drop in response to a firing signal. A weak inkjet is an inkjet that responds intermittently to a firing signal or that responds by ejecting ink drops having a mass that is different than the ink drop mass corresponding to the characteristics of the firing signal for the inkjet. As used in this document, 'inoperative inkjets' refers to inkjets that are either missing inkjets or weak inkjets. Systems and methods have been developed that can enable inoperative inkjets to recover the ability to respond to firing signals.
"Current detection methods include a test pattern being formed on an image receiving member and then digital data of the test pattern on the surface are generated. In an offset imaging device, the image receiving member is a rotating drum or belt. The digital data are produced by illuminating the drum or belt surface and generating an electrical signal that corresponds to the intensity of the light reflected from the surface. The signal is generated by an electro-optical sensor that is positioned to receive light reflected from a small portion of the drum or belt surface. By arranging a plurality of electro-optical sensors across the width of the drum or belt, the entire width can be used to generate reflected light received by the electro-optical sensors. The responses of the electro-optical sensors produce a digital image corresponding to the ink image on the drum or belt. The ink drops on the surface reflect light at an intensity that is different than the positions on the surface that do not have ink.
"Evaluating a digital image produced by illuminating an image drum or belt can be difficult because the surface may generate noise in the digital image. A significant amount of image data processing is required to detect the presence of ink on an image receiving surface and to distinguish ink from defects in the image receiving surface or noise. Additionally, precise measurements of detected ink positions are required to enable the detected ink on the image receiving surface to be correlated to the inkjet that ejected the ink. Thus, significant processing resources are expended to analyze the image data of a test pattern on an image receiving surface and to correlate the data from that analysis to the identification of inoperative inkjets. Improving the ability of inkjet imaging systems to detect inoperative inkjets efficiently remains important to such systems."
In addition to the background information obtained for this patent application, VerticalNews journalists also obtained the inventors' summary information for this patent application: "A method of inkjet printer operation enables inkjets to be recovered without hindering ink image printing. The method includes delivering to the inkjet in the printhead a first signal configured to operate a piezoelectric actuator in the inkjet, receiving a second signal from the piezoelectric actuator, the second signal corresponding to a response of the piezoelectric actuator to the first signal, and identifying a condition of the inkjet with reference to the second signal, the identified condition corresponding to one of the inkjet being blocked by a particle, the inkjet being blocked by air, and the inkjet being ready to eject ink.
"An inkjet printer implements the method to enable inkjet recovery without hindering ink image printing. The printer includes a printhead controller configured to generate and deliver to the inkjet in the printhead a first signal configured to operate a piezoelectric actuator in the inkjet, and a controller configured to receive a second signal from the piezoelectric actuator, the second signal corresponding to a response of the piezoelectric actuator to the first signal, and identify a condition of the inkjet with reference to the second signal, the identified condition corresponding to one of the inkjet being blocked by a particle, the inkjet being blocked by air, and the inkjet being ready to eject ink.
BRIEF DESCRIPTION OF THE DRAWINGS
"The foregoing aspects and other features of a system and method that enable inoperative inkjet detecting without image data analysis are explained in the following description, taken in connection with the accompanying drawings.
"FIG. 1 is a schematic diagram of a printhead assembly used in a printer implementing the process of FIG. 4.
"FIG. 2 is a graph of an example of a firing signal and a clearing signal.
"FIG. 3 is a schematic diagram of an exemplary interface for detecting the response of a plurality of actuators to a driving signal.
"FIG. 4 is a flow diagram of a process for detecting inoperative inkjets.
"FIG. 5A, FIG. 5B, and FIG. 5C are representations of responses of a piezoelectric transducer under different load conditions.
"FIG. 6 is a schematic diagram of a prior art printer in which the process of FIG. 2 can be implemented."
URL and more information on this patent application, see: Burress, Edward F.; Jones, Brent R. System and Method for Clearing Weak and Missing Inkjets in an Inkjet Printer. Filed
Keywords for this news article include:
Our reports deliver fact-based news of research and discoveries from around the world. Copyright 2014, NewsRx LLC
Most Popular Stories
- 5 Notable Hispanic Technology Executives
- Top Hispanic Tech Companies Push for the Top
- Rand Paul Tops Presidential Straw Poll at Conservative PAC Conference
- Tesla's Alt-Energy Future Aims for Massive Lithium-Ion Battery Production
- New Chat App, Yik Yak, Causes Problems for Students
- China Urges Malaysia Flight Emergency Response
- Gas Prices May Jump from Calif. Emissions Law
- Obama Meets with Ukraine Prime Minister Wednesday
- Russia, Crimea Discuss Referendum
- Visa, MasterCard Team Up to Focus on Payment Security