Abstract: A method and apparatus for detecting media type by aligning a media type detector onto a media, with sufficient force, in a media manipulation or sensing apparatus, such that the media type detector will accurately detect a type of media of a media when the media is tilted. A media manipulation or sensing apparatus, where the media type detector is arranged before a picking mechanism, with the media type detector including a force applying mechanism to apply force to a housing sled that is aligned onto the media, and with the housing sled being able to rotate with the media as the media tilts.

Abstract: A method for reducing visual printing defects produced by an ink jet printer includes the steps of providing a first printhead nozzle array spaced apart from a second printhead nozzle array in a main scan direction; defining a plurality of rasters for scanning during a first unidirectional scan of the first printhead nozzle array and the second printhead nozzle array; and printing on a print medium with both the first printhead nozzle array and the second printhead nozzle array to form printing lines traced along at least a portion of the plurality of rasters during the first unidirectional scan, wherein the first printhead nozzle array is controlled to print in a first shingling pattern and the second printhead nozzle array is controlled to print in a second shingling pattern.

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: An ink jet printing apparatus forms a printed image on a print medium based on image data. The apparatus includes an ink jet print head having ink ejection nozzles in a nozzle array. Ink is ejected from the nozzles and onto the print medium as the print head scans across the print medium in a scan direction, thereby forming the image on the print medium. The nozzle array on the print head includes a first substantially columnar array of nozzles aligned with a print medium advance direction which is perpendicular to the scan direction. The first array has a first upper subarray pair that includes a first upper left and a first upper right subarray of nozzles. The first upper left and a first upper right subarrays each include a substantially linear arrangement of n number of nozzles having equal nozzle-to-nozzle spacings. The nozzle-to-nozzle spacing in the first upper right subarray is equivalent to the nozzle-to-nozzle spacing in the first upper left subarray.

Abstract: One method operates a pick motor and a separate feed motor to pick and feed a sheet for printing. Desired pick and feed motor velocities are obtained from respective first and second functions of sheet position. Sheet position for obtaining both desired motor velocities is determined by the pick system until a predetermined event. The feed-system sheet position is synchronized to the pick-system sheet position upon the happening of the event. Sheet position for obtaining both desired motor velocities is determined by the feed system after the event. Another method operates a printer pick motor and includes starting picking by driving the pick motor in a first direction, to move a sheet forward, with an input sufficient to prevent any teetering transitions between peaks and valleys of an encoder sensor output which would be falsely counted as forward motion by a single-channel encoder.

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 ink jet printing apparatus forms a printed image on a print medium based on image data. The apparatus includes an ink jet print head having ink ejection nozzles in a nozzle array. Ink is ejected from the nozzles and onto the print medium as the print head scans across the print medium in a scan direction, thereby forming the image on the print medium. The nozzle array on the print head includes a first substantially columnar array of nozzles aligned with a print medium advance direction which is perpendicular to the scan direction. The first array has a first upper subarray pair that includes a first upper left and a first upper right subarray of nozzles. The first upper left and a first upper right subarrays each include a substantially linear arrangement of n number of nozzles having equal nozzle-to-nozzle spacings. The nozzle-to-nozzle spacing in the first upper right subarray is equivalent to the nozzle-to-nozzle spacing in the first upper left subarray.

Abstract: A method for synchronizing the print start position for a printer carriage on an inkjet printer that includes the steps of: (a) providing an encoder signal indicative of a position of an inkjet printer carriage relative to a substrate being printed upon or a printer platen, where the encoder signal is an alternating voltage signal with an encoder signal frequency; (b) filtering and dividing the encoder signal to provide a fire pulse signal, where the fire pulse signal is an alternating voltage signal with a fire pulse signal frequency that is a multiple of the encoder signal frequency; (c) detecting a rising edge of the encoder signal preceeding a predetermined print start position of the printer carriage; (d) upon detection of the rising edge of the encoder signal in step (c), detecting a next falling edge of the fire pulse signal; (e) upon detection of the next falling edge of the fire pulse signal in step (d), detecting a count of the next rising edges of the fire pulse signal; and (f) assigning a synchron

Abstract: A method of printing a print image on a print medium using a printer includes providing a text printing mode, wherein a first predetermined number of bits identify a selected character to be printed. A host based printing mode is provided wherein selected bits each indicate whether a corresponding pixel should be printed. The printer is initialized to print in either one of the text printing mode and the host based printing mode. A second predetermined number of bits of a data stream associated with the print image to be printed are received within the printer. The second predetermined number of bits is examined to determine a presence of a command therein. The printer is enabled to print in an enabled printing mode. The enabled printing mode includes either the text printing mode or the host based printing mode, dependent upon the examination of the second predetermined number of bits. The printer is used to print on the print medium in the enabled printing mode.

Abstract: A method of printing a print image on a print medium using a printer includes providing a text printing mode, wherein a first predetermined number of bits identify a selected character to be printed. A host based printing mode is provided wherein selected bits each indicate whether a corresponding pixel should be printed. The printer is initialized to print in either one of the text printing mode and the host based printing mode. A second predetermined number of bits of a data stream associated with the print image to be printed are received within the printer. The second predetermined number of bits is examined to determine a presence of a command therein. The printer is enabled to print in an enabled printing mode. The enabled printing mode includes either the text printing mode or the host based printing mode, dependent upon the examination of the second predetermined number of bits. The printer is used to print on the print medium in the enabled printing mode.

Abstract: A system and method for controlling a stepper motor wherein the amount of memory space needed to store a phase table is minimized. The stepper motor controller comprises a memory sized to store data representing a plurality of states for current outputs to be supplied to a first winding of a stepper motor and from which are derived current outputs for the first winding and a second winding of the stepper motor. A finite state machine is coupled to the memory. The finite state machine comprises a first address register that stores an address for data in the memory for a present state of the first winding and a second register that stores an address for data in the memory for a present state of the second winding.

Abstract: The invention is a host-based stepper motor controller that reduces velocity overshoot and settling time. A typical embodiment of the invention will include a stepper motor, a carrier mechanically coupled to the stepper motor, a processor for controlling the stepper motor and a driver circuit allowing communication between the processor and the stepper motor. The processor control reduces velocity overshoot and settling time by guaranteeing that each move begins on the stepper motor phase that optimally reduces velocity overshoot and settling time. The processor generates an initial value indicative of the extent of a current move of a carrier mechanically coupled to a stepper motor. Next, the start phase of the current move is determined along with the direction of the next move.

Abstract: The invention is directed to a method of controlling an operating temperature of a printhead in an ink jet cartridge assembly, with the printhead having a plurality of ink emitting orifices and a plurality of corresponding heater elements. A cooling rate of the printhead which occurs during inoperation of the heater elements is established. A heating rate of the printhead which occurs as a result of firing at least one of the heater elements is determined. A period of time is set. A variable representing a control temperature of the printhead is calculated, dependent upon each of the cooling rate and the heating rate during the period of time. The operating temperature of the printhead is controlled, dependent upon the value of the variable representing the control temperature.

Abstract: A laser printer (3) can initiate a line of printing only when the sweep of the laser light reaches a point in its cycle. An inkjet printer (5) moves paper by stepper motor in increments. Switch (9) senses the paper (15) to determine the location of paper in path (6) with respect to nominal printing locations of the laser printer. The closest nominal position is selected for printing. The paper may lead or lag the selected position. Switch (11) senses the paper to determine the location of paper in the path with respect to nominal printing locations of the inkjet printer. Two leads are added to reach a net greater lead, a lag is subtracted from a lead, and two lags are added to reach a net greater lag. The closest nominal position is then selected. This assures that registration does not vary by more than one half of the spacing between nominal locations of the second printer.