Sign e.g. postal mark, printing method for use in e.g. postage meter, involves determining forward moving speed of document in printing machine, and synchronizing forward moving speed and printing speed of sign on document in machine

摘要

The method involves determining a forward moving speed of a document e.g. envelope, in a document printing machine, based on estimation of displacement of the document in a longitudinal direction and/or transverse direction. The displacement of the document is estimated based on comparison of images of zones of document. The forward moving speed of the document and a printing speed of the sign on the document are synchronized in the machine. The printing speed of the sign on the document is controlled based on the forward moving speed of document. An independent claim is also included for a printing machine for printing a sign on a document, comprising a printing head.