Process and apparatus for detecting printed marks
AssigneeFocke & Co. (GmbH & Co.)
InventorsHeinz Focke, Eckhard Grundmann
Life of this patent
Estimating the term…
Abstract
The invention relates to a process and an apparatus for automatically detecting printed marks which are applied at regular spacings to material webs. The invention is based on the problem of improving the detection of printed marks when separate prints are applied between the printed marks in the same movement path of the printed marks. This problem is solved in that the widths of printed sections and the spacings between printed sections are determined and, if the width and spacing essentially correspond to predetermined values, a printed section is detected as being a printed mark.
Claims6
A process for severing or connecting moving webs (15, 17) which have printed sections at regular spacings with printed marks (37, 38, 39) and separate prints (40, 41, 42) in the same path of movement as the printed marks, said process comprising the steps of:
- determining widths (43) of the printed marks, and regular spacings (44) between adjacent printed sections, and, when a width (43) and a spacing (44) essentially correspond to respective predetermined values, detecting a printed section as being a printed mark (37, 38, 39);
- in response to a detected printed mark (37, 38, 39), initiating an operation for connecting a finishing web (15) to a new web (17) to connect the finishing web (15) and the new web (17) in a correctly positioned manner such that the printed marks (37, 38, 39), in a connecting region of the webs, also have spacings corresponding to the regular spacings of the printed marks (37, 38, 39) on the moving webs;
- determining a remaining length, of a web (15, 17) wound on a reel (13, 14), and the reel diameter from an angle of rotation (φ) of the reel, and
- from an angle of rotation of a deflection roller which runs along with the web, by taking the circumference of the deflection roller into account, or
- from a length of a piece of web which is drawn off the reel (13, 14), and
- from a displacement path of a carriage (19, 20) which carries along the web;
- and
- using the reel diameter for converting measured angle-of-rotation values (φ) of the reel into web lengths,
- wherein the reel has a rotational speed equal to:
- factor1/reel diameter * (machine rotational speed + factor2 * oscillatory deviation), wherein factor1 and factor2 are proportionality factors.
An apparatus for severing or connecting moving webs (15, 17) which have printed sections at regular spacings with printed marks (37, 38, 39) and separate prints (40, 41, 42) in the same path of movement as the printed marks,
- said apparatus comprising a sensor (22, 23) for scanning the printed sections, and
- an evaluation unit which is connected to the sensor (22, 23), and which, in response to a sensor signal, determines widths (43) of the printed marks, and spacings (44) between adjacent printed sections, and, when a width (43) and a spacing (44) essentially correspond to predetermined respective values, detects a printed section as being a printed mark (37, 38, 39);
- said apparatus also comprising:
- means for connecting a finishing web (15) to a new web (17) so that the finishing web (15) and the new web (17) are connected in a correctly positioned manner such that, in a connecting region of the finishing and new webs, the printed marks (38, 39, 40) are at spacings which correspond to said regular spacings of the printed marks (38, 39, 40) on the webs;
- an angle-of-rotation sensor for measuring an angle of rotation (φ) of a reel onto which a web (15, 17) has been wound;
- an angle-of-rotation sensor for measuring an angle of rotation (φ) of a deflecting roller (29) which runs along with the finishing web (17);
- a counting mechanism for counting the revolutions of the deflecting roller (29);
- and
- a sensor (35) for sensing the length of a piece of web which is drawn off from the reel (13, 14), and for sensing a displacement of a carriage (19, 20) which carries along a web (13, 14).
Dependencies are inferred from the claim text.