Typewriting machines – Including control of format by programmed-control-system
Patent
1999-04-12
2000-12-26
Hilten, John S.
Typewriting machines
Including control of format by programmed-control-system
400 70, 400 61, 400579, 400582, 226 31, B41J 1144
Patent
active
061648485
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
Method and circuit arrangement for printing a print image.
The present invention relates to a method for printing a print image on an endless stock in relation to a predetermined position in an electrographic printer.
2. Description of the Related Art
Electrographic printers are known in which a motor drives a transport means that transports the stock past a transfer printing station, essentially according to a predetermined print speed. During the printing process, print images produced by a printing control unit are printed successively on the stock at the transfer printing station with the print speed. If the transport means communicates a forward motion to the stock by means of positive locking, as is for example the case given the engagement of transport pins in transport holes of a stock perforated in the edge regions, then within determinate limits a constrained movement is realized between the stock and the transport means.
If, however, the transport means communicates the forward motion to the stock by means of non-positive locking, in that a rubberized transport roller or a transport strip stands in non-positive contact with the stock, a constrained movement between the stock and the transport roller or, respectively, transport strip is prevented by various influencing factors. These influencing factors include the microslippage that occurs in that the non-positive connection between the drive roller and the stock so that alignment is not one hundred percent guaranteed. Another influencing factor is to be found in the mechanical tolerances in the manufacture of the drive roller and its mounting in the transport means. A constrained movement between the stock and the drive roller thus does not take place. Since the transport speed of the stock thus never agrees entirely with the speed of the drive roller, a synchronous operation between the stock and the print process is excluded. If, for example, pre-printed form material, applied using offset printing, is present on the stock, in which numbers or letters are supposed to be printed in predetermined form fields during the print process, an offset, due to the minimal speed difference, between the letters and the form fields becomes larger with each printed form. An interruption of the print process in order to correct the offset is unavoidable.
However, the cited problems with respect to the offset also occur when the transport means communicates the forward motion in positively locked fashion to the stock. In this case, a clock generator is fastened to a photoconductor drum in the transfer printing station, which clock generator, via a control circuit for the phase (PLL--phase locked loop) generates the frequency of a stepped motor for driving the transport means, and for an illumination row for the illumination of the photoconductor drum. A disadvantage of this solution is that mechanical stiffnesses, network frequency oscillations, etc., are not completely corrected. Moreover, more complex electronic components are required for the realization of the phase controlling, which mostly operate according to an analog design, i.e. process continuous voltage values.
The object of the invention is to indicate a simple digital solution for printing endless stock that enables an offset-free printing in relation to a predetermined position.
This object is solved by means of a method having the features of patent claim 1. The invention proceeds from the assumption that given essentially constant transport speed of the stock, the offset becomes cumulatively larger from print image to print image. Accordingly, in order to correct the offset, only minimal speed modifications of the transport speed of the stock are necessary. The transport speed can accordingly be used as a reference quantity for a measurement of the offset, despite slight fluctuations.
In the invention, markings are present on the stock at regular intervals, for the positioning of the print images in the direction of transport. At the begi
REFERENCES:
patent: 3808971 (1974-05-01), Staamann
patent: 4684276 (1987-08-01), Frei et al.
patent: 4949104 (1990-08-01), Negoro et al.
patent: 5779124 (1998-07-01), Akira
patent: 5809390 (1998-09-01), Jackson
patent: 5820007 (1998-10-01), Crowley
patent: 5839688 (1998-11-01), Hertel et al.
Japanese Abstract, 01025163, Jan. 27, 1989.
Japanese Abstract, 06099638, Dec. 4, 1994.
Japanese Abstract, 55-164180, Dec. 20, 1980.
Japanese Abstract, 57-174288, Oct. 26, 1982.
Japanese Abstract, 5-155080, Jun. 22, 1993.
British Library Cataloguing in Publication Data, "Closed-loop control".
Hilten John S.
Nolan, Jr. Charles H.
Oce Printing Systems GmbH
LandOfFree
Process and circuit for printing a print image does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process and circuit for printing a print image, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process and circuit for printing a print image will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-988015