Abstract: A method of optimizing a relationship between fire energy and drop velocity associated with a printhead is provided. A test pattern is printed by selectively supplying energy distribution signals to a plurality of actuators of the printhead. The energy distribution signals have distinct energy profiles. The test pattern is scanned to obtain drop velocity information corresponding to the energy distribution signals. Based on the drop velocity information, an energy profile is determined that optimizes the relationship between fire energy and drop velocity.
Type:
Grant
Filed:
November 25, 2002
Date of Patent:
December 30, 2003
Assignee:
Lexmark International, Inc.
Inventors:
David G. King, Carrie A. Klusek, Patrick L. Kroger, Kent L. Ubellacker
Abstract: A method of imaging substance depletion detection in an imaging device. The method includes the steps of identifying a theoretical coverage of an imaging substance for a first area of a sheet of print media; determining an actual coverage of the imaging substance for the first area of the sheet of print media; comparing the theoretical coverage with the actual coverage; and determining whether a depletion of the imaging substance has occurred based on a result of the comparing step.
Abstract: An analog encoder system repeatedly switches back and forth between monitoring of first and second encoder output signals to track movement of a structure associated with the encoder. Switching between signals is controlled according to an upper intersection amplitude and a lower intersection amplitude of the two encoder output signals.
Type:
Grant
Filed:
July 3, 2001
Date of Patent:
July 29, 2003
Assignee:
Lexmark International, Inc.
Inventors:
Christopher Alan Adkins, Lucas David Barkley, Michael Anthony Marra, III
Abstract: A system is described for compensating for misalignments in an ink jet printer having an ink jet print head cartridge that includes a heater chip. The system includes determining alignment adjustment information related to the misalignments in the ink jet printer, loading the alignment adjustment information into a volatile memory device on the heater chip, and accessing the alignment adjustment information from the volatile memory device. The system also includes generating nozzle control signals based at least in part on the alignment adjustment information. The nozzle control signals are selectively provided to resistive heating elements in the heater chip, thereby heating ink in ink chambers adjacent the heating elements and ejecting ink droplets toward a print medium. The timing of the nozzle control signals is adjusted based upon the amount of misalignment in the various components of the printer and print head.
Type:
Grant
Filed:
April 6, 2001
Date of Patent:
July 8, 2003
Assignee:
Lexmark International, Inc.
Inventors:
Frank Edward Anderson, William Paul Cook, George Keith Parish, Susan Marie Zearfoss
Abstract: A method of analog encoder initialization involves repeatedly adjusting an encoder light element energization level and dc offsets of the encoder channels to produce desired signals.
Type:
Grant
Filed:
August 2, 2002
Date of Patent:
May 20, 2003
Assignee:
Lexmark International, Inc.
Inventors:
Christopher Alan Adkins, Michael Anthony Marra, III, Jay William Vessels
Abstract: A method and system for controlling a stepper motor that may be used in a paper feed rolling arrangement of a printer. The method includes storing step mode selection data in combination with time data in a single table for retrieval and use by a controller.