Hewlett-packard Development Company, L.p.

Cesar Fernandez

Carlos Millan-Lorman

Jason Cassidy Hower

Jose Galmes

Timothy Wagner

Bruce A Stephens

Santiago Reyero

Robert F Little

Richard W Riper

Carlos Millan

Srinivas Bhakthavatsalam

Santiago Garcia Reyero

Alisher Alikhodjaev

Jonathan Lee Brown

David Florez

Jose M Galmes

Timonthy Wagner

Virginia Hewlett-Packard Española SL Palacios

In an example implementation, a method of adjusting frame length in an inkjet web press includes measuring a time T1 between a first sensor sensing a first mark and a second sensor sensing a second mark, and measuring a time T2 between the second sensor sensing the second mark and the first sensor sensing a next first mark. The method includes adjusting a gap between printed frames when T1 does not equal T2.

Frame length adjustment

In one example a method is disclosed for printing duplex images. The method includes printing an image on side A of media, including an alignment mark. Detecting the alignment mark with a sensor. The velocity of the media is determined when the alignment mark is detected. Printing an image on side B of the media where the location of the image on side B is dependent on the velocity of the media. In another example a printer is disclosed that uses the method to print duplex images.

Duplex printing

Examples disclosed herein relate to front-to-back registration of a printed content onto a print medium. In one example, a trigger signal generated by a sensor upon detection of a trigger mark on a first surface of a print medium is received. The trigger mark includes a leading edge and a trailing edge, wherein the leading edge and the trailing edge are non-parallel. Based on the trigger signal, a distance of the trailing edge from a point on the leading edge is determined. Once determined, a measure of lateral wander of the print medium with respect to the print path is obtained. The measure of the lateral wander is determined by comparing the distance between the leading edge and the trailing edge, with a threshold value.

Front-to-back registration of printed content

In an example implementation, a method of adjusting frame length in an inkjet web press includes measuring a time Tbetween a first sensor sensing a first mark and a second sensor sensing a second mark, and measuring a time Tbetween the second sensor sensing the second mark and the first sensor sensing a next first mark. The method includes adjusting a gap between printed frames when Tdoes not equal T

An example method for operating a printing system in accordance with aspects of the present disclosure includes receiving, at a printing unit, a print job, receiving, at the printing unit, a trigger generated by a finishing unit, and initiating the print job based on the generated trigger.

Printing system

In one embodiment, a method includes applying at least one invisible mark to media, sensing the at least one invisible mark with separate sensors, and determining a speed of the media from signals of the separate sensors.

Determining a speed of media

Exemplary embodiments of the invention include methods of adjusting the print resolution of an inkjet printhead having a region of poor performance such that printing occurs outside the region of poor performance. Exemplary embodiments also include systems utilizing the methods.

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San Diego, CA, United States of America

Cesar Fernandez