Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
  • H04N1/387—Composing, repositioning or otherwise geometrically modifying originals
  • H04N1/393—Enlarging or reducing
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
  • H04N1/40—Picture signal circuits

Definitions

• Figure 3 illustrates a medium with a pattern produced according to an example.
• Measurement section 120 is arranged to measure a size of an image produced by the image forming section 1 10. According to the present example the measurement section 120 measures a length of the image along a path direction 150 of the medium 1 , but alternative or additional measures of image size (e.g. an image width or area) may be measured, depending on the image size variation to be corrected.
• the measurement section 120 may include an inline optical detector arranged to optically detect the image size.
• immediately preceding y images may be averaged, and the averaged size used to determine an adjustment to be applied to a next image.
• the average size of the preceding y pages may be taken as the "current" size, and a correction applied based on the difference between the current size and the target size.
• a rolling average may be used, such that the n th image is based on images n-y...n-1 , and the n+1 th image is based on images n-y+1 ...n.
• the averaging and adjustment are applied in groups, e.g. with an average size being derived based on images n-y...n-1 and the same average size being used to determine the adjustment for all of images n...n+y-1.
• Target is the target size (e.g. page length in microns) and OldMeasure and NewMeasure are previously measured sizes of different pages (e.g. page lengths in microns of sheets n-1 and n, respectively).
• the adjustment is to be applied to sheet n, and OldMeasure and NewMeasure respectively represent the sizes of sheets n-1 and n.
• the adjustment may be based on (e.g. proportional to)
• the adjustment may be such that the adjusted image has a size closer than the average size to the target size.
• the image forming section 1 10 is based on digital press technology, and the adjustment of the size of the image may be performed by the adjustment section 130 controlling a dynamic mirror of the image forming section 1 10.
• the adjustment section 130 may control the image forming section 1 10 in a suitable manner.
• Figure 5 shows a method 500 according to an example.
• the method begins at 510 and proceeds to 520, in which reference marks are printed onto a sheet. A main image may also be printed onto the sheet. Then, at 530, the positions of the reference marks are measured. At 540, the measured positions are compared with predetermined positions. At 550, the size of a subsequent image is adjusted based on the comparison, and at 560 the subsequent image is printed to a sheet. Where, at 570, it is determined that further sheets are to be printed, the method returns to 520, otherwise the method terminates at 580.
• the predetermined positions may be determined based on previously performed measurements of positions of reference marks.
• the previously performed measurements may have been performed on one or more initial sheets of the print run.
• the method proceeds to 660, where it is determined whether the size of the current image is acceptable. For example, this may involve comparison of the measured size with the target, and determining whether the measured size is within a predetermined tolerance of the target. Where the size is not acceptable, an adjustment is applied at 670 to adjust the size of a subsequent (e.g. the next) image, and the method returns to 620, where size data of the next image is collected (following printing of the image).
• Figure 7 shows an example of image size (y-axis) against print number (x-axis) for an unadjusted print run plotted as "x" 710, and a print run with size adjustments according to an example of the invention plotted as solid squares 720.
• Figure 7 also shows the target size used in the adjusted print run, line 730.
• examples of the present invention result in a significant improvement in consistency of the image size over the print run.
• the functional blocks described herein are not necessarily embodied by distinct components, and in particular components may be shared between functional blocks, and functional blocks may be embodied by a number of cooperating components.
• Functional blocks may be embodied by processors performing computer-readable instructions.
• Computer readable instructions may be provided in any suitable volatile or non-volatile storage medium, such as memory, ROM, hard disk, etc. The storage medium may be non-transient.

Landscapes

• Engineering & Computer Science (AREA)
• Multimedia (AREA)
• Signal Processing (AREA)
• Accessory Devices And Overall Control Thereof (AREA)

Priority Applications (1)

Applications Claiming Priority (1)

Publications (1)

Family

ID=46650524

Family Applications (1)

Country Status (1)

Citations (4)

• 2012
  • 2012-07-30 WO PCT/EP2012/064900 patent/WO2014019604A1/fr not_active Ceased

Patent Citations (4)

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