Method for controlling the orientation and/or position of sheets processed on a printing machine

1. A method for processing sheets on printing machines, the method comprising the steps of:

providing a printing machine having a detector for controlling orientation and/or position of the sheets;

providing a sheet suitable for use in the production of banknotes or security documents, said sheet being provided with at least one marking embedded in the sheet, which marking is embedded in the sheet during manufacturing thereof, prior to processing of the sheet on the printing machine, the marking being disposed in a selected location of the sheet and defining a unique orientation and/or position of the sheet;

feeding the sheet into the printing machine;

using the detector to check for the presence or absence of the marking at the selected location on the sheet and/or of characteristic features of the marking;

issuing a warning signal if the marking is not detected at the selected location or if the characteristic features of the marking are not detected at the selected location; and

printing the sheet using the printing machine if no warning signal is issued.

2. The method according to claim 1 , wherein the marking is a metallic and/or magnetic strip or thread embedded in the sheet.

3. The method according to claim 2 , wherein each sheet comprises a plurality of metallic and/or magnetic strips embedded parallel to one another in the sheet.

4. The method according to claim 1 , wherein the marking is a watermark embedded in the sheet.

5. The method according to claim 4 , wherein each sheet comprises a plurality of watermarks embedded in the sheet, the watermarks being disposed in a matrix-like arrangement.

6. The method according to claim 5 , wherein the location of the marking on the sheet defines a unique position and orientation of the sheet.

7. The method according to claim 1 , wherein the marking has an asymmetrical shape defining a unique position and orientation of the sheet.

8. The method according to claim 7 , further comprising the step of printing a matrix-like arrangement of prints onto the sheets and wherein the marking is provided for each of the prints.

9. The method according to claim 1 , further comprising the step of printing a matrix-like arrangement of prints onto the sheets and wherein the marking is provided for each of the prints.

10. The method according to claim 1 , wherein the sheets are processed sequentially in a plurality of successive printing machines and wherein the checking of the marking and the issuance of the warning signal are performed on each of the successive printing machines.

11. The method according to claim 10 , wherein the plurality of successive printing machines includes at least an offset printing machine for performing offset printing of the sheets, an intaglio printing machine for performing intaglio printing of the sheets and a numbering machine for numbering the sheets.

12. A method for controlling orientation and/or position of a sheet during processing thereof on a printing machine, comprising the steps of:

providing a sheet suitable for use in the production of securities, said sheet being provided with a marking embedded in the sheet during manufacturing thereof, prior to processing of the sheet on the printing machine; and

using the marking to control the orientation and/or position of the sheet during processing on the printing machine.

13. The method according to claim 12 , wherein the marking is a metallic and/or magnetic strip or thread embedded in the sheet.

14. The method according to claim 12 , wherein the marking is a watermark embedded in the sheet.