Patents by Inventor David H. Donovan
David H. Donovan has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 9258454Abstract: Embodiments of printer optical sensing error determination are disclosed.Type: GrantFiled: February 16, 2006Date of Patent: February 9, 2016Assignee: HEWLETT-PACKARD DEVELOPMENT COMPANY, L.P.Inventors: David H Donovan, Behnam Bastani
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Patent number: 8870326Abstract: A printer is disclosed in one example. The printer controls the amounts of the inks that are used when printing. The printer prints colors near saturation onto a media using mostly a first ink and prints saturated colors onto the media using mostly a second ink. The second ink has a reduced loading of the colorant in the first ink.Type: GrantFiled: October 19, 2011Date of Patent: October 28, 2014Assignee: Hewlett-Packard Development Company, L.P.Inventors: David H. Donovan, Shilin Guo
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Patent number: 8573731Abstract: A method for density error correction is disclosed. In one embodiment, the method includes a) calculating an average density error for at least one row of an image considering density errors for printhead elements employed to print the at least one row, and a number of passes that the printhead elements will utilize to print the at least one row, b) calculating a density error correction value for the at least one row considering the average density error, and c) applying the density error correction value to adjust ink flow from the printhead elements while printing the at least one row.Type: GrantFiled: April 30, 2009Date of Patent: November 5, 2013Assignee: Hewlett-Packard Development Company, L.P.Inventors: Behnam Bastani, David H Donovan, Bryan S Ly
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Publication number: 20130100192Abstract: A printer is disclosed. The printer prints colors near saturation using mostly a first ink and prints saturated colors using mostly a second ink. The second ink has a reduced loading of the colorant in the first ink.Type: ApplicationFiled: October 19, 2011Publication date: April 25, 2013Inventors: David H. Donovan, Shilin Guo
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Patent number: 8100489Abstract: A method for double-sided printing may include ejecting printing fluid from a fluid ejector to a platen configured to receive print media, the platen supporting a nonabsorbent substrate. In any sequence, a first print media side and a second print media side may be printed by ejecting printing fluid from the fluid ejector to the first print media side, and contacting the second print media side with the nonabsorbent substrate to transfer printing fluid from the nonabsorbent substrate to the second print media side. A method for double-side printing may further include increasing the contact between the second print media side with the nonabsorbent substrate to increase transfer of printing fluid.Type: GrantFiled: October 17, 2008Date of Patent: January 24, 2012Assignee: Hewlett-Packard Development Company, L.P.Inventors: Dale D. Timm, Jr., John A. Dangelawicz, David H. Donovan, Shilin Guo, Behnam Baslani, David Luis Pereira
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Publication number: 20100277530Abstract: A method for density error correction is disclosed. In one embodiment, the method includes a) calculating an average density error for at least one row of an image considering density errors for printhead elements employed to print the at least one row, and a number of passes that the printhead elements will utilize to print the at least one row, b) calculating a density error correction value for the at least one row considering the average density error, and c) applying the density error correction value to adjust ink flow from the printhead elements while printing the at least one row.Type: ApplicationFiled: April 30, 2009Publication date: November 4, 2010Inventors: Behnam Bastani, David H. Donovan, Bryan S. Ly
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Publication number: 20090153605Abstract: A method for double-sided printing may include ejecting printing fluid from a fluid ejector to a platen configured to receive print media, the platen supporting a nonabsorbent substrate. In any sequence, a first print media side and a second print media side may be printed by ejecting printing fluid from the fluid ejector to the first print media side, and contacting the second print media side with the nonabsorbent substrate to transfer printing fluid from the nonabsorbent substrate to the second print media side. A method for double-side printing may further include increasing the contact between the second print media side with the nonabsorbent substrate to increase transfer of printing fluid.Type: ApplicationFiled: October 17, 2008Publication date: June 18, 2009Inventors: Dale D. Timm, JR., John A. Dangelawicz, David H. Donovan, Shilin Guo, Behnam Baslani, David Luis Pereira
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Patent number: 7417768Abstract: CDE is measured for each nozzle array, to enable modification of a mapping between input image data and intended printing marks to compensate for the CDE. Printing proceeds using the modified mapping, which is either an optical-density transformation of data to printing marks or a spatial-resolution relation between image data and intended pixel grid. The density transformation preferably includes a dither mask (but can be error-diffusion thresholding instead); the resolution relation includes scaling of image data to pixel grid. For some invention forms, CDE includes printing-density defects, measured and used to derive a correction pattern—in turn used to modify halftone thresholding. For other forms CDE includes swath-height error, but still this is measured and used to derive a correction pattern etc. For still other forms, however, CDE includes swath-height error and correction takes the form of scaling.Type: GrantFiled: October 13, 2000Date of Patent: August 26, 2008Assignee: Hewlett-Packard Development Company, L.P.Inventors: David H. Donovan, Miquel Boleda, Johan Lammens, Francesc Subirada
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Publication number: 20030027544Abstract: A remote radio receiver includes audio circuitry, a user selection interface, user control circuitry and input/output interface. The audio circuitry is for receiving a digital audio stream and playing extracted audio signals over a speaker. The user control circuitry generates control signals as a result of a user interacting with the user selection interface. The input/output interface provides connection to a remote computer. The input/output interface forwards the digital audio stream from the remote computer to the audio circuitry. The input/output interface forwards the control signals from the user control circuitry to the remote computer.Type: ApplicationFiled: August 1, 2001Publication date: February 6, 2003Inventors: David H. Donovan, Betsy C. Huntingdon, Christopher G. Wykoff
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Patent number: 6390585Abstract: A system and method are provided for selectively warming a printhead in response to a relatively sudden change in one or more operating conditions of a printer. These operating conditions may include, for example, duty cycle, print density, print speed, and the like, which can be empirically detected, calculated, or predicted. Because sudden changes in printing conditions generally do not occur frequently, the printhead will not be warmed at all for much of its operating time. This reduces dramatic fluctuations in drop volume, to prevent thermal banding, while not maintaining the printhead at an undesirably high temperature.Type: GrantFiled: July 21, 1998Date of Patent: May 21, 2002Assignee: Hewlett-Packard CompanyInventors: Stefano Schiaffino, Sebastia Castelltort, David H. Donovan
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Patent number: 6293657Abstract: Techniques for pausing and resuming printing operations in mid-plot while reducing visible artifacts. A pause row/swath location is determined at which printing is to be paused. In one pause/resume mode, printing of all rows and all pixels from commencement of printing through the row location is completed, and no pixels in rows immediately following the row location are printed. The printing is paused for a time interval, and operations such as a pen refill can be performed. Printing is resumed at a resume row location immediately following the pause row location to print only rows following the pause row, wherein wet ink is not applied to locations printed prior to the pausing. In another pause/resume mode, in a multi-pass print of an image, the pause occurs upon completion of a pass without completing all printing prior to the pause row. Following the pause interval, printing is resumed, as though a pause had not occurred.Type: GrantFiled: October 30, 1998Date of Patent: September 25, 2001Assignee: Hewlett-Packard CompanyInventors: Javier Salvador Lagares Garcia, David H. Donovan
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Patent number: 6276777Abstract: A variable maximum operating temperature for a printhead is defined and utilized within both a system and a method. The variable maximum operating temperature varies according to one or more operating conditions within a printer into which the printhead may be installed. If a detected temperature of the printhead is greater than the variable maximum operating temperature for a detected operating condition, the printer will be shut down to prevent overheating. Accordingly, the system and method extend the useful life of the printhead and reduce paper waste.Type: GrantFiled: July 21, 1998Date of Patent: August 21, 2001Assignee: Hewlett-Packard CompanyInventors: Stefano Schiaffino, Sebastia Castelltort, David H. Donovan
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Patent number: 6076915Abstract: In various methods, image registration variations among test patterns are used to calibrate misalignment among one or more printheads, paper advance distance, different portions of an inkjet printhead, or bidirectional printhead alignment. A set of test patterns are printed. Each pattern includes a reference portion and a varying portion. The varying portion is changed from pattern to pattern in a manner for testing a parameter being calibrated. An optical sensor scans each test pattern. The parameter setting for the lest pattern having the highest reflectance (i.e., most blank space) is selected as the calibrated parameter value.Type: GrantFiled: August 3, 1998Date of Patent: June 20, 2000Assignee: Hewlett-Packard CompanyInventors: Paul David Gast, Mark S Hickman, David H. Donovan, Xavier Gros, Antoni Gil Miquel
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Patent number: 5946012Abstract: An inkjet drop ejection system comprises a combination of printhead components and ink, mutually tuned to maximize operating characteristics of the printhead and print quality and dry time of the ink. Use of a short shelf (distance from ink source to ink firing element), on the order of 55 microns, provides a very high speed refill. However, it is a characteristic of high speed refill that it has a tendency for being over-damped. To provide the requisite damping, the ink should have a viscosity greater than about 2 cp. In this way, the ink and architecture work together to provide a tuned system that enables stable operation at high frequencies. One advantage of the combination of a pigment and a dispersant in the ink is the resultant higher viscosity provided. The high speed would be of little value if the ink did not have a fast enough rate of drying. This is accomplished by the addition of alcohols or alcohol(s) and surfactant(s) to the ink.Type: GrantFiled: June 4, 1998Date of Patent: August 31, 1999Assignee: Hewlett-Packard Co.Inventors: Kenneth J. Courian, John L. Stoffel, Richard A. Sader, Keshava A. Prasad, Steven L. Webb, David H. Donovan, Jules G. Moritz, III, Brian J. Keefe, Steven W. Steinfield, Winthrop D. Childers
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Patent number: 5874974Abstract: An inkjet drop ejection system comprises a combination of printhead components and ink, mutually tuned to maximize operating characteristics of the printhead and print quality and dry time of the ink. Use of a short shelf (distance from ink source to ink firing element), on the order of 55 microns, provides a very high speed refill. However, it is a characteristic of high speed refill that it has a tendency for being overdamped. To provide the requisite damping, the ink should have a viscosity greater than about 2 cp. In this way, the ink and architecture work together to provide a tuned system that enables stable operation at high frequencies. One advantage of the combination of a pigment and a dispersant in the ink is the resultant higher viscosity provided. The high speed would be of little value if the ink did not have a fast enough rate of drying. This is accomplished by the addition of alcohols or alcohol(s) and surfactant(s) to the ink.Type: GrantFiled: February 28, 1996Date of Patent: February 23, 1999Assignee: Hewlett-Packard CompanyInventors: Kenneth J. Courian, John L. Stoffel, Richard A. Sader, Keshava A. Prasad, Steven L. Webb, David H. Donovan, Jules G. Moritz, III, Brian J. Keefe, Steven W. Steinfield, Winthrop D. Childers
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Patent number: 5851273Abstract: In accordance with the invention a set of dyes suitable for use in ink-jet inks and method for formulating the same are provided. A specific dye set for formulating the yellow, cyan, magenta, and optionally black inks is disclosed, comprising Direct Yellow 132, Direct Blue 199, Magenta 377, and optionally Pacified Reactive Black 31 dyes, respectively. This dye set provides ink-jet prints able to match printed color standards such as specification for web offset publications (SWOP) and Euroweb, with excellent lightfade and pen reliability performance.Type: GrantFiled: July 2, 1997Date of Patent: December 22, 1998Assignee: Hewlett-Packard CompanyInventors: Peter C. Morris, David H. Donovan, Gregg A. Lane, Larrie A. Deardurff
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Patent number: 5401303Abstract: Halo effect seen at the interface between a first ink, exhibiting sharp edge acuity, and a second ink, having low surface energy, is addressed by adding certain fluorocarbon compounds to the first ink. Edge acuity of the first ink is maintained.Type: GrantFiled: April 26, 1994Date of Patent: March 28, 1995Assignee: E. I. Du Pont de Nemours and CompanyInventors: John L. Stoffel, David H. Donovan, Loren E. Johnson, John R. Moffatt