Abstract: A reciprocating linear encoder includes a linear encoder and a sensor. The linear encoder is configured to latch, follow and release print media in a periodic motion. The sensor is responsive to movement of the linear encoder, and is configured to output a signal associated with print media movement.

Abstract: A printer can anticipate the power needs of a print head. The printer receives a print job and a measurement of print density as a function of time for the print job from a printer driver that determines print density as a function of time based on data representing the print job. The printer includes a processor for receiving a print job, a print head and a power system for supplying power to said print head. The processor controls a voltage applied by the power system to the print head in accordance with the measurement of print density.

Abstract: A print medium with encoded data and a print media detection system for use in detecting at least one characteristic of the sheet of print medium based on the encoded data are disclosed. The encoded data is designed to minimize its visual perceptibility. The print media detector is designed to recognize various characteristics of print media based upon the encoded data and transmit information regarding these characteristics to a printing device so that one or more operating parameters of the printing device can be adjusted to help optimize print quality for the particular characteristics of a particular print medium. A printing device including the print medium and print media detection system is also disclosed. A method of detecting one or more characteristics of print media used in a printing device is additionally disclosed.

Abstract: A system for ink short protection for signaling to inkjet printheads includes a differential signaling driver having a first and a second terminal, a differential signaling receiver having a first and a second terminal, a first capacitor in series between the first terminals, a second capacitor in series between the second terminals, and circuitry for reducing charge accumulation on the capacitors. A method for ink short protection and a printing mechanism having such an ink short protection system are also provided.

Abstract: A drying station produces a boundary layer relative to wet media when present therein. An air source moves air relative to the boundary layer. A sound source applies sound energy to the boundary layer.

Abstract: Overall print quality is improved via a method whereby an actual image is printed, a virtual image is defined based on image data, and the actual and virtual images are compared to identify a printhead error pattern which may be used to correct subsequent printing errors. This typically is accomplished via a system which employs an optical device which views an actual image to produce optical data, and a controller which derives a virtual image from image data provided to the printhead. The controller then compares the actual and virtual images to identify an error pattern, and modifies subsequent image data to compensate for perceived errors.

Abstract: An inkjet printing mechanism includes a media support holding media in a printzone and a carriage scanning an inkjet printhead across the printzone. A heating element is supported by the carriage and moves relative to the media.

Abstract: A print media preheating method and apparatus uses heat, vacuum, and mechanisms for drying and flattening a sheet prior to ink-jet printing thereon. Pre-shrinking the media, driving out and substantially reducing inherent moisture content prior to depositing wet ink thereon provides greater flatness in the print-zone whereby ink-jet print quality is improved.

Abstract: Described are techniques for preventing the forces attributable to shrinkage of print media from shifting print media on the media-carrying belt in the vicinity of the print zone. In one approach, a “hold zone” is identified immediately upstream of the print zone. In the hold zone, a mechanism is employed for securing the media to be immovable relative to the belt. The hold mechanism provides sufficient force to overcome tension transmitted to the dry portion of the media as the remaining portion shrinks. In one embodiment, the hold mechanism is a roller that pinches the media against the belt. In another embodiment, the amount of vacuum pressure applied to the belt is regulated so that the suction force applied to the media in the hold zone is greater than the suction force applied to the media in the portion upstream of the hold zone.

Abstract: Overall print quality is improved via a method whereby an actual image is printed, a virtual image is defined based on image data, and the actual and virtual images are compared to identify a printhead error pattern which may be used to correct subsequent printing errors. This typically is accomplished via a system which employs an optical device which views an actual image to produce optical data, and a controller which derives a virtual image from image data provided to the printhead. The controller then compares the actual and virtual images to identify an error pattern, and modifies subsequent image data to compensate for perceived errors.

Abstract: A system for ink short protection for signaling to inkjet printheads includes a differential signaling driver having a first and a second terminal, a differential signaling receiver having a first and a second terminal, a first capacitor in series between the first terminals, a second capacitor in series between the second terminals, and circuitry for reducing charge accumulation on the capacitors. A method for ink short protection and a printing mechanism having such an ink short protection system are also provided.

Abstract: A printer has a media transport with a rigid, air-transmissive platen. A movable air-transmissive flexible web overlays the platen. A suction device communicates with the platen to draw air through the web and through the platen such that a sheet of media carried on the web is biased toward the platen. A valve sheet overlays or underlies the platen, and includes a plurality of shut-off elements, each movable in response to temperature changes between a closed position in which the element contacts a portion of the platen to prevent air flow through that portion of the platen, and an open position, in which the element is spaced apart from the platen to admit air to the platen portion. The shut off elements may include resistive heaters and bimetallic strips, so that application of electricity generates heat to flex the strip to an open position.

Abstract: A method and apparatus for ink-jet drop generator ink drop characteristics uses a drop detector target mounted in the printing zone of a hard copy apparatus. The detector target includes a matrix of individual elements sized approximately the same as pixel targets in printing operations. A detector target is mounted adjacently to the paper path of the apparatus such that test firing can be accomplished prior to each swath scan across the print media. By pre-firing nozzles to be used in the next swath at the detector target, actual trajectory errors and drop volumes can be analyzed in real-time. Alternate embodiments and methods are described.

Abstract: A method of ink jet printing wherein at least one row of pixels adjacent a leading edge of a print medium and/or trailing edge of the print medium is printed using a print mode that employs fewer passes than the print mode utilized for printing rows that are further from such edges.

Abstract: A print media preheating method and apparatus uses heat, vacuum, and mechanisms for drying and flattening a sheet prior to ink-jet printing thereon. Pre-shrinking the media, driving out and substantially reducing inherent moisture content prior to depositing wet ink thereon provides greater flatness in the print-zone whereby ink-jet print quality is improved.

Abstract: A system for ink short protection for signaling to inkjet printheads includes a differential signaling driver having a first and a second terminal, a differential signaling receiver having a first and a second terminal, a first capacitor in series between the first terminals, a second capacitor in series between the second terminals, and circuitry for reducing charge accumulation on the capacitors. A method for ink short protection and a printing mechanism having such an ink short protection system are also provided.

Abstract: A system for ink short protection for signaling to inkjet printheads includes a differential signaling driver having a first and a second terminal, a differential signaling receiver having a first and a second terminal, a first capacitor in series between the first terminals, a second capacitor in series between the second terminals, and circuitry for reducing charge accumulation on the capacitors. A method for ink short protection and a printing mechanism having such an ink short protection system are also provided.

Abstract: When the data rate of incoming data is less than the print speed, there can be pauses in the print job. During a pause, wet ink may cause cockle growth at a portion of the media sheet within the print zone. To reduce such cockle growth a reduced number of nozzles are used when the data rate is less than the print speed. In particular the print swath is reduced. Only a downstream subset of nozzles are used, in effect shortening the portion of the media sheet receiving ink. The wet portion of the media sheet then is closer to the downstream edge of the print zone and soon away from the printhead. A guide shim also is advanced to maintain a flat media sheet near the active nozzles.

Abstract: Apparatus and method are disclosed herein that compensate for print engine and encoder expansion or contraction in a printing device. An embodiment of an apparatus in accordance with the present invention for use in a printing device having a print engine and an encoder that indicates where the print engine should print on a print medium, includes a first target on the encoder and a second target on the encoder. The apparatus also includes a first sensor configured to output a first signal upon detection of the first target and a second sensor configured to output a second signal upon detection of the second target. The apparatus additionally includes a computing device coupled to the first sensor, the second sensor and the print engine, which is configured to determine a difference between receipt of the first signal and the second signal, and to adjust when the print engine prints on the print medium based on this difference.

Abstract: A print medium with encoded data and a print media detection system for use in detecting at least one characteristic of the sheet of print medium based on the encoded data are disclosed. The encoded data is designed to minimize its visual perceptibility. The print media detector is designed to recognize various characteristics of print media based upon the encoded data and transmit information regarding these characteristics to a printing device so that one or more operating parameters of the printing device can be adjusted to help optimize print quality for the particular characteristics of a particular print medium. A printing device including the print medium and print media detection system is also disclosed. A method of detecting one or more characteristics of print media used in a printing device is additionally disclosed.