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.

Abstract: A printhead alignment sensor for an ink jet printer includes at least two terminals defining a gap therebetween. An electrical measuring device detects a change in an electrical parameter between two of the terminals when ink is in the gap between the at least two terminals.

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. An energization level of an encoder light element may be controlled in accordance with which encoder output signal is being monitored.

Abstract: A method for determining ink drop velocity of a printhead located at a gap above a print medium. A first ink mark is printed at a first printhead velocity. A second ink mark is printed at a different (in magnitude and/or direction) second printhead velocity. The ink for the second ink mark is ejected from the printhead at the same print ejection position used for the first ink mark plus a predetermined offset distance (if any). The distance between the ink marks is measured. The ink drop velocity is calculated using the measured distance, the predetermined offset distance, the first and second printhead velocities, and the predetermined gap. In another method, an ink mark is printed, a distance is measured between the ink mark and the ink-ejection position, and the ink drop velocity is calculated using the measured distance, the printhead velocity, and the gap.

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: A method for determining the skew of a printhead of a printer. At least three images are printed which are at least partially aligned substantially along the printhead scan direction with the middle image printed from one of the upper and lower portions of the printhead and with the adjacent images printed from the other of the upper and lower portions of the printhead. A sensor is moved in the printhead scan direction over the images. A function is calculated from the sensor output, wherein the calculated function indicates the skew of the printhead.

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.

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.

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.

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.

Abstract: A connection module including a base including a forward set of points located in a forward plane and a rearward set of points located in a rearward plane, the forward and rearward planes defining a junction therebetween. The connection module further includes a cable including a plurality of contacts located thereon, each contact being shaped and located to engage one of the points. The connection module has a backing element including a piece of sheet-like material, a set of contact protrusions on the piece of material, and at least one stiffening element on the piece of material. Each of the contact protrusions is shaped and located to engage the cable and urge one of the contacts into engagement with one of the points. The stiffening element is generally aligned with the junction when the contact protrusions engage the cable and urge the contacts into engagement with one of the points.

Abstract: A method of positioning an ink jet printhead in a printer includes dividing a bitmap into a plurality of rows of tiles. A subset of the rows of tiles to be printed in a next pass of the printhead is identified. Printable ones of the tiles in the subset of rows are identified. The printable tiles contain printable data. Within each printable tile, a top most location of the printable data and at least one of a left most location of the printable data and a right most location of the printable data are identified. A print medium is advanced in a feed direction until a portion of the print medium corresponding with the top most location of the printable data of at least one printable tile is substantially aligned with a top nozzle of the printhead.