Abstract: A method for automatic pen alignment in a printing apparatus, wherein the printing apparatus has a scan direction or x-axis and a media advance direction or y-axis, orthogonal to said scan direction or x-axis, the method comprising the steps of performing a pen alignment process, determining an alignment correction algorithm to be applied during subsequent printing, to compensate for the misalignment determined in said pen alignment process, measuring an output angle of the media, defined as the angle between the y-axis and the actual direction of advance of the media, with at least one optical sensor arranged stationary on the printing apparatus, and employing the measured output angle to modify the alignment correction algorithm to be applied during subsequent printing.

Abstract: A printer device comprising a mechanism adapted to generate an image on an image surface, the device comprising a sensor adapted to image a predetermined optical object located substantially on the image surface, the device being adapted to determine at least one dimension of the object's image and thereby determine the distance separating the mechanism and the image surface.

Abstract: Illumination utilizing a plurality of light sources is disclosed. In one embodiment, an illumination level is set to result in a desired contrast level. Calculations are made to derive electrical current values for each of the plurality of light sources which will illuminate a plurality of selected locations at the set illumination level.

Abstract: A method for automatic pen alignment in a printing apparatus, wherein the printing apparatus has a scan direction or x-axis and a media advance direction or y-axis, orthogonal to said scan direction or x-axis, the method comprising the steps of performing a pen alignment process, determining an alignment correction algorithm to be applied during subsequent printing, to compensate for the misalignment determined in said pen alignment process, measuring an output angle of the media, defined as the angle between the y-axis and the actual direction of advance of the media, with at least one optical sensor arranged stationary on the printing apparatus, and employing the measured output angle to modify the alignment correction algorithm to be applied during subsequent printing.

Abstract: A multicolor-printer has at least a first and a second print station, first and second optical sensors and a surface recordings comparator. The first and second print stations are arranged to print images on a surface of a moving recording medium. The first and second optical sensors view, at the first and second print stations, an area of the recording medium surface to obtain at least one first surface recording, in a manner related to the first print station's image printing, and second surface recordings, respectively. A storage is arranged to store the first surface recording. The surface recordings comparator is arranged to test, during the recording medium movement, for correspondence of second surface recordings with the stored first surface recording.

Abstract: A method for image recognition. In the method, a section of an element is imaged while the element is at a first speed to obtain a first image pattern. The section of the element is also imaged while the element is at a second speed to obtain a second image pattern. The first speed differs from the second speed. In addition, the apparent speeds of the element in the first image pattern and the second image pattern are made to appear approximately the same.

Abstract: A media-positioning sensor assembly in one embodiment of the invention is disclosed that includes a mechanism and a media-positioning sensor. The mechanism moves back and forth over media along a first axis. The media advances past the mechanism along a second axis perpendicular to the first axis. The media-positioning sensor is situated on the mechanism and is to detect positioning of the media relative to the mechanism along at least one of the first axis and the second axis.

Abstract: A position-measuring circuit is described for use with an analog position encoder of the kind comprising a code member and at least two sensors for sensing successive marks on the code member during relative movement between the code member and sensors, the sensors providing two oscillating quadrature signals. The circuit comprising means for obtaining a relatively coarse measure of position by detecting successive instants t0–t3 at which the amplitudes of the sensor signals are equal or at which the amplitude of one signal is equal to the inverse of the amplitude of the other signal. The amplitude of one of the signals or its inverse is stored at each detection instant to alternately establish relatively high and low threshold levels. A fine measure of position at an arbitrary instant T is obtained as a function of the instantaneous amplitude P of one of the signals and the difference between neighbouring high and low thresholds levels.

Abstract: A sensor system for detecting skew in print media along the feed path of a hardcopy device is disclosed. In one embodiment of the invention the system is arranged to generate a first image of a portion of print media at a first position along the feed path and to generate a second image of the portion of print media at a second position along the feed path, the system is arranged to compare the first and second images and thereby detect a change in the angle of skew of the media between the first and second positions.

Abstract: A sensor system for detecting skew in print media along the feed path of a hardcopy device is disclosed. In one embodiment of the invention the system is arranged to generate a first image of a area of print media at a first position along the feed path and to generate a second image of the area of print media at a second position along the feed path, the system is arranged to compare the first and second images and thereby detect a change in the angle of skew of the media between the first and second positions.

Abstract: An embodiment of the invention is disclosed in which media advances at a first speed to an interim position based on signals from a first sensor having a first accuracy. While the media is advancing at the first speed, signals are accumulated from a second sensor having a second accuracy greater than the first accuracy. Upon the media reaching the interim position, an actual position of the media is adjusted based on the signals accumulated from the second sensor.

Abstract: A method of an embodiment of the invention is disclosed in which a linear imaging array captures a first one pixel-wide image of media, and the media is effectively advanced relative to the linear imaging array. The linear imaging array captures a second one pixel-wide image of the media, and the first and the second one pixel-wide images are compared to determine relative advancement of the media.

Abstract: A method of an embodiment of the invention is disclosed in which a linear imaging array captures a first one pixel-wide image of media, and the media is effectively advanced relative to the linear imaging array. The linear imaging array captures a second one pixel-wide image of the media, and the first and the second one pixel-wide images are compared to determine relative advancement of the media.

Abstract: An embodiment of the invention is disclosed in which media advances at a first speed to an interim position based on signals from a first sensor having a first accuracy. While the media is advancing at the first speed, signals are accumulated from a second sensor having a second accuracy greater than the first accuracy. Upon the media reaching the interim position, an actual position of the media is adjusted based on the signals accumulated from the second sensor.

Abstract: A method for image recognition. In the method, a section of an element is imaged while the element is at a first speed to obtain a first image pattern. The section of the element is also imaged while the element is at a second speed to obtain a second image pattern. The first speed differs from the second speed. In addition, the apparent speeds of the element in the first image pattern and the second image pattern are made to appear approximately the same.

Abstract: A printer device having a plurality of print heads for printing onto a print medium. Each of the print heads having a plurality of nozzles formed into at least two rows. A service station housed within the printer device having a plurality of service station units for performing servicing operations on the print heads. A plurality of ink drop detector modules being integrated into respective ones of the service station units for detecting malfunctioning nozzles on the plurality of print heads. The ink drop detector modules may be configured to test the nozzles of each row of nozzles on at least one of the print heads simultaneously. And, according to a preferred embodiment, each row of nozzles of each print head are tested simultaneously to thereby substantially reduce the amount of time required to test the functionality of the nozzles.

Abstract: A method and apparatus for servicing a printer which has a processor and a display includes a component having circuitry for communicating a status of the component, where the processor, coupled to the component, further includes second circuitry for determining a service requirement for the component in response to analyzing the status of the component. Also included is an indicator, observable by a user performing the service at least when the display is not observable by the user, for indicating the service requirement to the user. The indicator may be included with the particular component, and may be a visual and/or an audible indicator.

Abstract: A sensor system for determining a position relative to a codestrip comprising a plurality of graduations spaced apart in a first direction, said system comprising first and second sensors arranged to move substantially in said first direction relative to said graduations and to output signals corresponding to the detection of said graduations, said system further comprising a differential screw adapted to adjust the spacing between said first and second sensors substantially in said first direction such that the outputs of said first and second sensors may be brought into a selected phase relationship.

Abstract: A printer device having a plurality of print heads for printing onto a print medium. Each of the print heads having a plurality of nozzles formed into at least two rows. A service station housed within the printer device having a plurality of service station units for performing servicing operations on the print heads. A plurality of ink drop detector modules being integrated into respective ones of the service station units for detecting malfunctioning nozzles on the plurality of print heads. The ink drop detector modules may be configured to test the nozzles of each row of nozzles on at least one of the print heads simultaneously. And, according to a preferred embodiment, each row of nozzles of each print head are tested simultaneously to thereby substantially reduce the amount of time required to test the functionality of the nozzles.

Abstract: A method and apparatus for servicing a printer which has a processor and a display includes a component having circuitry for communicating a status of the component, where the processor, coupled to the component, further includes second circuitry for determining a service requirement for the component in response to analyzing the status of the component. Also included is an indicator, observable by a user performing the service at least when the display is not observable by the user, for indicating the service requirement to the user. The indicator may be included with the particular component, and may be a visual and/or an audible indicator.