EP2176043A1

EP2176043A1 - Method for cutting a planar printing plane

Info

Publication number: EP2176043A1
Application number: EP08774329A
Authority: EP
Inventors: Didier Dubesset; Eric Vilain; Bart Vanhauwaert
Original assignee: Grafitroniks
Current assignee: Grafitroniks
Priority date: 2007-06-28
Filing date: 2008-06-26
Publication date: 2010-04-21
Also published as: CA2688663A1; US20100175521A1; WO2009000883A1

Abstract

The invention relates to a method for cutting a planar printing plane. The invention belongs to the field of cutting a planar printing plane, such as a sheet or a plate, following a pattern previously printed on said printing substrate. The method comprises: detecting (155) at least one sequence of points characteristic of the geometry of a cutting outline on the basis of cutting marks; allocating (156) each detected characteristic point to at least one cutting outline; searching characteristic elements (outline edge, outline corner) of said outline on the basis of the characteristic points; and translating (164) the cutting outline into vectorial information for generating a cutting program of at least one cutting outline.

Description

Method for cutting a plane printing medium

Technical Field of the Invention

The present invention relates to a method for cutting a plane printing medium. It belongs to the field of cutting a flat printing medium, such as a sheet or a plate, around at least one pattern previously printed on this printing medium.

State of the art In the field of printing, it is known to print on a plane printing medium a plurality of patterns, then to cut the printing medium around the patterns to separate them from each other. By plane printing medium, there will be understood a printing medium shaped plate likely to have a natural holding, or a flexible sheet-like printing medium, such a sheet being able to be packaged and handled in roll. Such a printing technique is particularly applied to the field of photography or the like, such as for posters or other similar posters. For example, photographs or more generally patterns are printed in plurality on the print medium by being distributed on the surface corresponding to the front of the support. Commonly, these patterns have a perimeter of regular geometric shape, in particular rectangle, and are likely to be the same size (size) or respective sizes for the same print medium. Such patterns are also likely to have a periphery of complex shape, such as having at least partially curved areas.

This raises the general problem of cutting the print medium around the patterns. For this, it is implemented cutting devices, which are either integrated in the printing machine, or are separate from the latter.

For a description of the state of the art, reference is made to document FR-A-2 903 039. In the state of the art, DE-A-34.33.288 in the name of BAUMANN is also known in which a device and a cutting method based on a two-dimensional table with a carriage capable of moving a camera are described. video. In this state of the art, a complete image of the printed surface is obtained by successive sweeps of lines in a direction X. When the entire image has been acquired, each pixel of this image is analyzed so that when the pixel corresponds to a mark or an outline registration, it is taken into account to generate an element of a cutting program. It is therefore through the analysis of each of the points of each of the contours to be cut that the cutting programs are carried out which are then implemented.

Such a state of the art provides a high accuracy of cutting even if the contours are completely arbitrary, but it imposes a very slow reading of the entire support, and it requires the knowledge of a very high number of points to obtain a good cutting accuracy.

Object of the invention

To overcome the drawbacks of this state of the art, the present invention relates to a method for cutting a flat printing medium around at least one previously printed pattern on the printing medium with cutting marks associated with the at least one a pattern, the method being of the kind in which a cutting learning step is performed by detecting cutting marks and a step of producing a cutting program of said at least one pattern, which program is subsequently executed by a machine cutting. The process consists of:

Detecting at least one sequence of characteristic points of the geometry of at least one cutting contour on the basis of the cutting marks;

• assign each detected characteristic point to at least one cutting contour; • search for characteristic elements (edge of contour, corner of contour) of said contour on the basis of said characteristic points, then

Translate the detected cutting contour into vector information for moving a cutting tool to generate said cutting program of at least one cutting contour.

According to one aspect of the method of the invention, the cutting contour being of polygonal shape, it consists of:

• determining the orientation of at least a first edge of the contour by the detection of at least two characteristic points; • determining an edge adjacent to a previous detected edge by detecting at least one characteristic point of said adjacent edge. According to one aspect of the method of the invention, it consists in determining at least one origin point of at least one path for detecting characteristic points of determined dimensions on the basis of configuration data and / or the detection of an element. characteristic of the printed medium such as an edge or a corner of the support.

According to one aspect of the method of the invention, the contour providing at least one determined internal margin with the useful printed interior surface of the pattern, in order to detect a characteristic point, it consists in determining said path of detection of characteristic points in the interior internal margin. and detecting during the path a transition of a detection characteristic, such as the color or the print brightness between the margin and the printed mark.

According to one aspect of the method of the invention, it comprises a step for detecting a wedge by detecting at least one characteristic point on a next edge adjacent to the previous detected edge by performing a search for characteristic points in the inner margin. audit edge detected previous.

According to one aspect of the method of the invention, in order to acquire at least one characteristic point of a contour, it consists in determining said characteristic point detection path in the internal margin of said contour by means of path segments of predetermined dimensions to reduce the acquisition time based on data of cutout contour formats.

According to one aspect of the method of the invention, in which the relative orientation of the adjacent edges is predetermined, it consists in associating the known relative orientation of the edge being detected with the determined absolute orientation of the previous detected edge to determine the direction of the inner margin and with the detection of a characteristic point on the edge being detected to deduce the directional coefficients of the line representative of the edge being detected. According to one aspect of the method of the invention, if a characteristic point is detected on a previous detected edge in a contour, a step of confirmation and / or reduction of the uncertainties on the directional coefficients of said line representative of the detected edge is performed. previous. According to one aspect of the method of the invention, it consists in determining the detection path of characteristic points of at least one cutting contour so as to progress in a first direction by acquiring the cutting contours one after the other:

selecting an origin point of the path for detecting characteristic points of a new contour by progressing along said first direction of the printed medium; then

- when an extension limit of the printed medium in said first direction has been reached, to choose a new origin point at the beginning of said first direction beyond the extension in a second direction of the detected contour which has the smallest extension in said second direction among the contours detected during the preceding progression in said first direction as long as an extension limit in said second direction has not been reached and to reiterate the progressing path so as to acquire at least one new contour not yet detected.

According to one aspect of the method of the invention, it consists in determining the detection path of characteristic points of all the cutting contours arranged along a first direction then, when the end of the extension of the first direction is reached, to cause a progression of the path in a second direction then to resume the detection sequence of the characteristic points of the cutting contours arranged in said first direction and to repeat the operation as the end the extension of the printed medium in the second direction is not reached.

According to one aspect of the method of the invention, when the printed medium is larger in said second direction than the extension in this direction of a table receiving the printed medium, it also comprises a step consisting, when the detection path of characteristic points has reached the end of the extension of the table receiving the printed medium in said second direction, to order an advance of the printed medium on said table receiving the printed medium, then to perform a step of detecting a new original position selected at the beginning of said second direction and the remaining unrecognized surface of the printed medium; and to resume the process of detecting the sequence of the characteristic points on the not yet completely recognized cutting contours.

Description of the figures. The present invention will be better understood, and details will arise from reading the description which will be made of embodiments in connection with the figures of the attached plates, in which:

- Figure 1 is a diagram explaining the main steps of an embodiment of the method of the invention;

FIGS. 2 to 5 are schematic views of parts of a printed medium for explaining certain steps of the method of the invention; and

FIGS. 6 and 7 are successive diagrams illustrating another example of the control method according to the invention. In Figure 1, there is shown a first embodiment of the method for cutting a plane printing medium around at least one previously printed pattern on the print medium. In the method, a cutting machine is used which mainly comprises a table 38 equipped with a gantry can receive a motorized carriage 150 under the action of a motor powered via a controller 152. The carriage 150 is movable in a first dimension or direction, for example Y, while the gantry (Not shown in Figure 1) can move in a second dimension or direction, for example X on the cross arrowed in Figure 1. A printed support 2, for example consisting of a large paper sheet, aligned according to the X and Y directions of the table, and on which the front of which were carried impressions 3, is arranged on the table 38. In the remainder of the description, the dimension term can indicate a direction or an extension along this direction.

The table 38 is equipped with means for removably and without wrinkling the printed support 2 relative to the movement of the gantry and its carriage 150. Particularly when the printed support 2 has a second dimension X larger than the corresponding dimension of the table 38, it is expected that the table 38 is provided with motorized means under the control of a controller 151 to advance and / or back the printed medium 2 at least a fraction of the second dimension X, so to process in several passes or phases the entire surface of the printed support 2. For this purpose, the controller 151 can supply, in a controlled manner, a feed motor according to the bidirectional arrow Z the printed medium when it is fixed relative to the table 38 and to control the means for fixing removably and without wrinkling, the printed support 2. Such a cutting machine, known from the state of the art, performs the cutting of the printed support 2 by means of a cutting tool 1, carried by the carriage 150. As described above, the printed support 2 carries images or patterns such as the pattern 3, and which are arranged and distributed on the printed support 2 at arbitrary locations, that is to say that, for the implementation of the method, there is no need to know "a priori" the dimensions, shapes, provisions of reasons.

It is known to have a cutting computer file associated with the printing file that has previously been used to produce the support. However, and especially for large printed media, the cutting files that were known in the state of the art do not make it possible to ensure accurate cutting and without losing the patterns. It has therefore been proposed to add around patterns printed as pattern 3, contours such as contours M ₁ which consist of solid or discontinuous lines around the zone containing each pattern such as pattern 3.

The contours are thus defined by cutting marks that are of two different kinds:

- A first kind of cutting mark consisting of simple local marks for defining a characteristic element of the cutting contour such as an edge or a corner;

a second kind of cutting mark consisting of a continuous solid line which completely surrounds the area occupied by the printed pattern 3.

The method makes it possible to recognize, in the absence of any "priori" knowledge of areas to be cut from the printed support 2, a cutting contour by learning using a reading of the cutting marks produced during printing. printed support 2.

DESCRIPTION OF THE CUTTING MACHINE

The cutting machine shown in FIG. 1 is connected to a computer or control automaton (not shown) which essentially supplies it with table moving information 154 and a moving information of the carriage 37. To simplify the figure, it is not necessary to has not represented a third control information of the cutting tool 1 which indicates to a motor element (not shown in Figure 1) associated with the cutting tool, an order to activate or deactivate the cutting according to the relative positions of the carriage 150 and its support frame on the table 38 relative to the areas in which the printed patterns to be cut.

Finally, the cutting machine produces a signal carrying a reading information which is produced by a detector or reading means 4, integral with the carriage 150. The detector 4 is preferably constituted by an optical sensor, capable of detecting, with a suitable adjustment, a contrast or a contrast transition between a light area and a dark area. In one embodiment, there is used as the clear zone of adjustment of the reading detector 4 a margin region disposed around the printed areas and mainly around the cutting marks which have been previously printed on the printed medium 2. Similarly, the area dark set on the detector 4 is chosen on the printing area of the actual cutting mark, for example, a printed line provided as a mark or cutting inscription.

When the carriage 150 describes a programmed path indicated to it by the carriage displacement information signal 37 applied to the controller 152, the detector 4 detects any transitions between light areas and dark areas when the detector 4 crosses or follows a line as a mark or cutting inscription.

When the detector 4 passes on other zones having other contrasts, the reading detector 4 is not activated. With the difference, when the reading detector 4 is activated, the relative position of the transition between a light zone, characteristic of a margin of preference without printing, and a dark zone, characteristic of a mark or inscription of cut, the coordinates of this position are inserted and stored in the read information 10 as coordinates of a characteristic point of a cutting contour as will be explained later. In the remainder of the description, detection paths of characteristic points of marks printed around the cutting contours are determined by the control of the X and Y displacements of the gantry and of the carriage carrying the reading detector 4. that unlike the state of the art, only a fraction of the points representative of the image of the printed medium 2 is analyzed which ensures a great speed in the execution of the method.

In FIG. 1, there is shown both learning means and the process cutting learning step that these means learning run. Such learning means are realized on the basis of a computer capable of executing a learning program which implements the method described, as will be explained later.

In FIG. 1, the cutting learning means, in which the main steps of the method have been represented, produce training output signals or data which are supplied to a module 164 capable of producing a cutting program, subsequently executed by the cutting machine described above.

Therefore, in order to cut a plane printing medium 2 around at least one pattern 3 previously printed on this printing medium, a cutting learning step is performed by detection of cutting marks and a production step. a cutting program subsequently executed by the cutting machine.

DESCRIPTION OF STEP 1 OF THE PROCESS: LEARNING

During the cutting learning step, the read detector 4 is driven by the carriage 150 along determined paths so that it is able to produce in the read information 10 sequences of characteristic points of the marks. so that it is possible to determine on the basis of the sequence of the detected characteristic points the geometry of a cutting contour.

For this purpose, the learning means execute a first step 155 of detecting a characteristic point. Such a characteristic point is obtained when the detector detects a correctly calibrated transition between a light zone, a dark zone and another light zone corresponding to the margins surrounding a dark line constituting a cutting mark.

When a characteristic point of a cutting mark has been obtained in step 155, the characteristic point is assigned to a contour being learned in a step 156.

When the sequence of characteristic points has a determined number of characteristic points assigned to a cutting contour, it is then possible, as will be described later, to reconstruct the geometry of the contour of cutting on the basis of only the characteristic points detected in the sequence of characteristic points.

When a characteristic point has been detected, according to tests which will be described later, the learning module or learning step makes it possible, during a step 158, to generate a vector displacement of the reading detector 4 by producing a piece of information. moving the carriage 37 by means of a controller 152.

When a new characteristic point is detected in the read information 10 produced by the read detector 4, the learning loop continues and the sequence of characteristic points increases during each step 155 executed.

When a characteristic point has been assigned to a contour being learned in step 156, a first test 157 is performed to determine whether the reading detector 4, carried by the carriage 150 on the table 38 has reached the end of a first dimension of the printed medium 2, such as the width Y of the printed medium 2 disposed on the table 38. If the first dimension, such as the width Y, has been reached (O; 157), a second test at step 159 to know if the reading detector 4, carried by the carriage 150 on the table 38 has reached the end of a second dimension of the printed medium 2, as the length Y of the printed medium 2, disposed on the table 38.

If one does not have (N; 159) reached the end of the second dimension on the table 38, in a step 163, a movement of the table 38 is performed by producing a table moving information 154 which is supplied to the control input of the controller 151 which makes it possible to temporarily release the removable fixing means of the printed support 2 on the table 38, and to pull the printed support 2 back from a table length 38 so as to allow to analyze and process a new length of printed media length 2. If (O; 159) reaches the end of the second dimension, then the production step of a cutting program is of step 164, which will be described later. The cutting program being produced by the cutting program production module during the step of production of cutting programs, it is transferred to the module 165 for executing the cutting program which controls the X and Y displacements of the carriage 150 which drives the cutting tool.

If one does not (N; 157) reach the end of the first dimension in the reading of the printed medium 2 by the reading detector 4, it is necessary to calculate an instruction or information for moving the carriage 150 so that the carriage 150 describes a determined trajectory on the basis of the sequence of the characteristic points already determined in step 155 or of initialization conditions before the first detection. For this purpose, the information generator 37 for moving the carriage

150 is capable of producing an instruction recognized by the controller to move the carriage from the current point on the table 38 to a destination point, for example defined by its coordinates relative to the current point where the carriage is located. Such information 37 is of the type: DEPLACEMENT_RELATIF dX, dY which indicates that the carriage must be moved from the point where it is, defined by its abscissa X and its ordinate Y, to a point of destination which is at a abscissa X '= X + dX, with dX displacement according to the second dimension, and an ordinate Y' = Y + dY, with dY displacement according to the first dimension.

During the travel of the carriage 37 from the current point (X, Y) to (X ', Y'), the reading detector 4 is activated as soon as it has encountered a mark or cut inscription on the printed medium 2. Read information 10 is generated that interrupts the path of the carriage 150 and indicates a new feature point (step 155) added to the sequence of feature points.

If no characteristic point has been detected, the vector motion generator 158, in the step for producing a carriage displacement information 37, produces a new relative displacement instruction taking into account that a new characteristic point n ' has not yet been reached, so that the path of the carriage 37 is continued on a new path segment of determined dimensions. Of course it is planned to program any path, or path segments, configurable and adjust the speed profile if desired.

The steps or means for generating the vector displacement information (dX, dY) of the detector 158 or of the table 163 also use two databases constituted by formats in a database 162 and instructions in a database 161 so that it is possible to define the paths or path segments of the carriage 150 as taught above. In particular, these databases 162 and 161 make it possible, for example, to determine the dimensions of a configurable path or path segment. In the case where the cut marks or inscriptions are rectangles, for example, a database of standard cutting formats of rectangles is used so that the displacement in (dX, dY) is of the order of the smallest multiple common between formats, whether in length or width, or both. Furthermore, the configurable paths or path segments are determined according to at least one scanning strategy of the surface of the printed medium 2 which reduces the learning time to a minimum duration.

According to a first strategy which will be explained using FIGS.

5, it is intended to perform a contour contour training by following the internal margin provided between the line of the inscription or printed cutting mark and the useful area of printing pattern 3.

In this first strategy, any detected characteristic point is assigned to the cutting contour during learning unless it has been detected that the contour being taught is closed by the acquisition of a last characteristic point. The next characteristic point is then assigned to a new cutting contour during learning.

In a second strategy which will be explained with the aid of FIGS. 6 and 7, provision is made to carry out a learning along a first dimension of the printed medium 2, then to carry out an advance according to the second dimension and to repeat as well as a description according to the first dimension has been described above. In this second strategy, a following characteristic point in the sequence of the characteristic points acquired during the step 155 may need to be assigned to another contour than the one that received the assignment (step 156) of the preceding characteristic point.

The database 161 of the instructions is fed by the operator of the cutting machine when installing the printed medium on the table, for example, to indicate an origin point of analysis which allows to arrange the carriage with the detector 4 at a given point of origin to achieve learning.

Likewise, the database 162 of the formats is fed by the operator during the installation of the cutting machine or during the opening of cutting campaigns of printed media. In the format database, geometric data and information on the geometry of the marks and inscriptions or cutting contours are recorded as well as on the particular provisions of the lines and margins surrounding the lines constituting the cutting marks as well as it will be explained later.

The format database 162 thus comprises information identifying and / or framing the inscriptions or cutting marks. This information will be described later.

In a particular embodiment, it is planned to insert, between the assignment step 156 of a characteristic point at a cutting contour during the training and the end-of-first-dimension test 157, a test of closing a contour during a step 165 (shown in parentheses in Figure 1, as a variant).

When the contour closure test is checked, the cutting contour is completely determined by the list of characteristic points that have been assigned to it and it is immediately executed the production of a cutting program during the step 164 of generating the cutting contour. 'a cutting program. When the cutting program based on the detected finite contour has been generated and if necessary after its execution, the control then returns to the end-of-first-dimension test. Of course, the carriage 150 returns to a registered position prior to calling the production step of the single detected closed contour cutting program. DESCRIPTION OF STEP 2 OF THE PROCESS: TRANSLATION IN CUTTING PROGRAM

In Figure 2, there is shown a diagram for explaining the module capable of performing the step of producing a cutting program or step 164 of the method of the invention. During a step 170, a control loop is initialized on all the N contours detected during the learning step (see FIG. 1) or in the case in which a group of contours, such a group, can be reduced to a single contour, is transmitted directly to the learning step. Each cutting contour # i is constituted by a list of characteristic points assigned to it in step 156 in the form of a cutting contour file #i. The file 164 is read by the module during the transmission of the data from the learning module to the production module of the cutting program. The file characterizing a cutting contour # i may have from 1 to B cutting edges, so that the cut must be organized with B successive commands of activation / deactivation and vector motion commands of the cutter 1 mounted on the cart 150.

A database 173, analogous to the format database 162, contains the predetermined cutting formats that are recorded by the operator during machine initialization or a cutting campaign. The data concerned by the command contour file # i are read 175, as well as the data corresponding to the geometric definition of the edge #j being read in the contour file 172. During the step 174, the data is generated. a cutting instruction which is constituted by a vector displacement order of the carriage and / or of the table intended for the controllers 151 and 152, followed by an order of activation of the cutting tool, of a vector displacement order while the cutting tool is active, then an order for raising or disabling the cutting tool. A cutting instruction is determined by a displacement of the carriage 150 carrying the cutting tool 1 from a cutting start point to a cutting end point according to a path determined according to the edge # j detected in the contour #i. Especially when the 5

outline #i is a rectangle, the edge #j is a line segment and the cutting instruction is then a line segment whose position relative to the edge #j is predetermined, for example in the inner margin of the cutting contour at a predetermined distance. The determination of the position of the cut with respect to the cutting contour determined during the learning is entered in a cutting database.

When the cut instruction corresponding to the reading of an edge of the outline file 172 has been executed, this instruction is passed 176 to a tool able to add the cutting instruction to a cutting program 177. The translating edges into cut instructions for the entire contour file # i for all of its B edges 172 is executed. When the contour file #i has been fully analyzed to produce the proper sequence of cut instructions, the loop i on the set of contour files is incremented. When the loop of the N outlines has been exhausted, the cutting program is then fully available 178 and can be executed 179 by a suitable processor associated with the cutting machine and which produces the displacement information sequences of the carriage 37 and the information possible of table movement 154, as well as the activation / deactivation commands of the cutting tool 1 and which are passed to the controllers 151 and 152 and the controller (not shown) of the cutting tool 1 on the carriage 150 .

FIRST READING STRATEGY "BY INTERNAL MARGIN" In FIG. 3, the upper left corner of a printed support 201 whose width 203 is arranged at the beginning of the table 38 of the cutting machine of FIG. The carriage 150 disposes the detector 4 on the point AO disposed near the edge of the printed sheet or support 201. A cutting mark, constituted by a solid line completely surrounding the area in which the printed pattern is to be cut, has was represented by corner 205.

On the other hand, the useful area 204 in which the printed pattern to be cut is also represented. Between the fictional zone 204 3 and the cutting line 205 is an internal margin 223 in which the brightness or the contrast, or any other optical characteristic detectable by the detector 4 of the cutting machine, is determined as a clear zone of adjustment. the transition contrast threshold for the read detector 4 (Figure 1). Similarly, outside of the cutout inscription 205 is provided an outer margin 221 which also has a clear bottom area which can be detected and recognized as such by the detector 4.

During the learning step, the acquisition of a sequence of characteristic points of step 155 is started; then a carriage displacement information 37 is generated for the controller 152 which produces a displacement of the detector 4 from the origin point AO according to the path 209. The origin point AO is a point determined from a base of configuration data (161; FIG. 1) and based on the detection of a characteristic element of the printed medium such as a side support edge or its corner. The determination of such an origin point of type 'AO' is repeated with each new contour discovered during the cutting learning step.

The path 209 is determined by the format information of the database 162 and corresponds, in an exemplary embodiment, to the direction of the second dimension Y represented on the reference of FIG. 3. Once the path 209 has been made, the carriage returns to the ordinate Y of the origin point A0 along the path 211, or any other path of the same kind, by shifting one step in the direction of the first dimension X. During a new parallel path and of the same length as the path 209, a path 213 makes it possible to meet a characteristic point A1 on the first edge of the first contour encountered. The first edge is rather directed in the direction of the first dimension X of the cutting training. The path sequence 209/211/213 ... is repeated until the first characteristic point A1 is detected using the read detector (4; FIG. 1). The coordinates of the characteristic point are assigned to a first contour being learned in step 156 (FIG. 1) and the control of the relative inclination of the first edge 207 on which the first point is executed is carried out. 7

characteristic A1 has just been detected. For this purpose, the detector vector displacement generator 158 of the learning means controls a displacement so that the reading detector 4 comes to be placed along a path 215 parallel to the paths 209 and 213 in order to capture or acquire a second characteristic point. A2 on the edge 207.

When the cutting inscriptions are constituted by a polygon such as a triangle or a rectangle, the data of two points A1, A2 makes it possible to completely determine the inclination of any edge of the contour as the first edge 207. Such a procedure can be executed for each edge of the contour being learned. If the polygonal contour is of known shape and the precision in the printing of the cutting marks is correct, there is no need to measure the inclination of the following edges of the contour after measuring the inclination of the first edge 207. It is sufficient to add the angle between the two adjacent edges, 90 ° here, to know the absolute inclination of the next adjacent edge. The data of the two points A1 and A2 makes it possible to determine the coefficients a, b and c of the equation aX + bY + c = 0 which defines the direction of the analyzed edge. The read information (10; FIG. 1) includes the coordinates of the characteristic points which make it possible to find or define the edges of the cutting contour. Likewise, if the edge is constituted by an arc of a circle, it is possible to obtain a correct definition of the arc of circle by the detection of three characteristic points.

In Figure 4, there is shown a procedure for detecting a corner in a polygonal contour as a rectangular contour. The procedure of acquisition of characteristic points described with the aid of FIG. 3 was continued, and the learning process is continued by commanding the carriage, by the information of movement of the carriage 37, a displacement along the path 227. which is performed according to the first dimension in the direction of a return to the ordinate of the origin point. When a characteristic transition of a line of a cut registration is detected, the edge 205 is then detected by its characteristic point A3. Thus, it is possible, by the data of three points, or of four points if the inclination of the edge 205 is not predetermined in the database formats, to completely define a corner 229 formed by the intersection of two edges 207 and 205.

From the detection of the first characteristic point of a contour, the sequence of the characteristic points is detected in the internal margin 223 of the outline 207, 205. This characteristic makes it possible especially when following an edge, such as the edge 207, in parallel. to be assured, in the case of a convex polygonal contour such as a rectangle, to detect the first characteristic point of an adjacent edge, such as the edge 205, at the edge 207 previously detected. Similarly, the data of the edge 207 and the first point A3 of the second adjacent edge 224 makes it possible to easily determine, in the case of a predetermined rectangular contour, the coordinates of the corner 229 here in X and Y coordinates with respect, for example, to the point of origin AO of FIG.

In Figure 5, there is shown an example of implementation of the method of this embodiment. The printed sheet or support 201 is disposed on the table of the cutting machine in a determined position, for example by a guide 202, and an origin point 230, of the same kind as the point AO of FIG. 3, is determined on the lower left corner in the drawing of Figure 5. A first path 231, similar to the path 209, is then controlled so as to come to acquire the two characteristic points a, b of a first edge 232 and its inclination. Then the path is continued so that the left-hand point c on the vertical edge is then determined, analogous to point A3 of FIG. 4, and the detector 4 is transferred along the vertical path in the internal margin 223 between the contour 205 and the useful surface 204 of the pattern to be cut so that it is possible to then reach the characteristic point d of the upper horizontal edge of the contour.

In the same way, once the characteristic point d of the acquired horizontal upper edge, the characteristic point e of the vertical right edge of the first contour on the left of FIG. 5 is acquired and the detector 4 is brought back to its original abscissa X according to the path 233. In this way, a rectangular contour is perfectly determined by the data of the two points a, b of the first horizontal edge 232, and three characteristic points. c, d and e, acquired respectively on the left vertical adjacent edge, the upper horizontal edge and the right vertical edge of the first edge.

When the detector 4 continues the trajectory 233 in the inner margin zone 223, a new characteristic point f is then detected on the horizontal lower edge, so that a first characteristic point for the lower right corner 234 is acquired, and which allows to confirm and / or to make more precise the determination of the orientation of the lower edge obtained using the two points a and b in 232. Similarly, the point g of the corner 234 on the right vertical edge of the first contour can to be acquired when the detector 4 accomplishes the crossing of this edge during the continuation 235 of its trajectory. The knowledge of the two characteristic points f and g of the corner 234 makes it possible to confirm and / or to make more precise the specification of the left cutting contour on the printed support of FIG. 5.

The first contour being acquired, as described with the aid of FIG. 1, it is possible either to order a cut of the acquired contour, or to wait for all the contours or a group of outlines have been acquired.

The process described for the first contour is then repeated by executing a displacement of the carriage 37 along the path 235. The new origin point of the type 'AO' (FIG. 3) is constituted by the last characteristic point of the preceding completely detected contour. As for the detection of the sequence of feature points for the first contour, the feature point detection path continues with the detection of a pair of feature points a, b to determine the position and orientation of the first horizontal edge 236 the second contour, right on the printed medium 201. In the same way as for the first contour, one successively acquires a characteristic point for each of the remaining edges, namely c for the left vertical edge, d for the upper horizontal edge, and e for the right vertical edge. In the same manner, the characteristic point detection path is determined along the path 237 to return to the first lower horizontal edge so as to acquire the characteristic points f and g of the wedge 238. to also achieve confirmation and / or improvement of the contour accuracy. The second rectangular contour is then completely acquired.

When the second rectangular contour is acquired, the process of acquiring a new rectangular contour is then repeated and the detector 4 is moved on its carriage so as to follow the path 239 on which the edge of the printed medium 201 is detected. We have thus detected the end of the first dimension Y or end of the extension of the printed medium in the first direction Y during the learning step.

Once the end of the first dimension Y has been detected in FIG. 5, the end of the second dimension X is tested (159; FIG. 1) so that if the end of this second dimension in the X direction of the reference point of the second dimension X FIG. 5 is not reached, a new origin point 244 of type 'AO' (FIG. 3) is determined which is situated at the same ordinate Y as the first origin point 230 and whose abscissa X is in the direction of the arrow 241 shown in Figure 5 is determined on the abscissa of the smallest detected contour. The new origin point 244 being acquired, it is then possible to continue the acquisition 245 of the other contours printed on the printed medium 2. It is noted that each time an original point of type 'AO' is used, the surface to be analyzed during the learning step is limited by the border 242 corresponding to the surface already analyzed. It is thus possible to advance the path of detection of characteristic points on the entire surface of the printed medium.

SECOND READING STRATEGY "BY SCANNING IN TWO DIMENSIONS"

In FIG. 6, the operator places the printing medium 2 on the carrier device 38. This operation is preferably performed by covering the carrier device 38 as much as possible with the printing medium 2, taking care that the patterns to be cut at best arranged in the reading and cutting surface covered by the possible displacements of the reading means 5 and the tool 1. In the exemplary embodiment illustrated, the carrier device 38 of the print medium 2 is arranged in a table and only the reading means 5 are movable to detect the information of reading 10. According to variants not shown, the table is movable in displacement being operable by the mobility means 29, alone or in complementarity with the reading means 5, or the carrier device 38 of the support of printing 2 is vertically extending and is movable while the reading means 5 are fixed. Other embodiments of the carrier device 38 of the print medium 2 and / or the relative mobility modalities between the printing medium 2 and the cutting tool 1 and / or reading means 5 are possible without to derogate from the defined rules of the modalities of drawing up the cutting program 6 and the reading program 32.

The operator enters the setpoint information, and more particularly in the case of example formats M1 M2 M3 M4 M5 M6 M7 patterns to be cut. Such setpoint information may already be present in memory and are entered only when necessary according to the reasons to be cut. Incidentally, the operator can select formats that the reading means 5 are likely to detect and / or their number. This last operation is not mandatory, the learning means and the recognition means, associated with the comparison means, being able to detect the different patterns to be cut whose set information is stored by the memory means of the device. However, this operation reduces the number and density of calculation operations that the device must perform to identify the different formats of the patterns to be cut. All the information entered by the operator constitutes a database relating, for example, to formats, geometric conformations, line thicknesses bordering the patterns to be cut, or even possible separation distances between this feature and a pattern or between two adjacent patterns or inscriptions, without prejudging a cutting program 6 and a reading program 32 to be developed during a learning cycle. The information in the database is used not only for dimensional accuracy when cutting the patterns, but also to control the moving means 31 while avoiding the use of the learning means. 9 when it is not necessary to identify and locate the pattern (s) to be cut.

At the end of a trajectory traversed by the reading means 5 in association with the implementation of the learning means 9, the device is able to compare the reading information previously recognized as revealing the presence of an inscription. and / or a pattern with the setpoint information 15, 19, d, e, D, C, to deduce therefrom one or more trajectories adapted according to the inscriptions and / or the patterns identified and to deduce from it the necessity or not of implement the learning means 9 together with this or these new trajectories.

The operator causes a start of read cycle aimed at developing a reading program and jointly a cutting program. This operation is likely to be performed from a validation key or other control element all or nothing analogous. A first trajectory 101-102 is by default close to an origin point 100, for example a starting point 101 located at a distance of about 10 mm from the origin point 100. The position of this point of start 101 can be set beforehand by the operator. It is desired to detect the edges of the patterns (images) and / or possibly a frame that surrounds them. The possible detection of a frame causes a cutting command parallel to the edges of this frame of a value that can be set by the operator. The cut is likely to be performed at the inner or outer border of the frame, or at any distance from the pattern inscribed in this frame. Such a cutting parameter can be entered and / or selected beforehand by the operator. This first trajectory is made at least in the entirety of a dimension of the print medium or at least according to the largest dimension of a pattern and / or an inscription that can be detected and whose format has been previously memorized as referred to above. In the case where the first trajectory 101 -102 does not reveal reading information relating to an inscription, the control means generate a vector reading information to cause a displacement of the reading means 5 along a second trajectory towards point 103. This reading vector information 34 relates to a step and / or direction previously set, such as from an input and / or selection made by the operator, and the means of learning 9 are not implemented. Then the control means 30 generate a read vector information 37 to cause a displacement of the reading means 5 along a third path to the point 104, the learning means being implemented. During this displacement of the reading means 5, reading information a and a 'are detected by the reading means 5, analyzed by the learning means 9 and the recognition means 11 associated with the comparison means 14,18. The device deduces the position of the point 105. This point 105 is situated between the first trajectory and the edge of the carrier device 38 of the print medium 2, and is located between the zones in extension of the points corresponding to the reading information a-a. . A parameter x is capable of being previously entered and / or selected by the operator to position the point 105 relative to the point a, and therefore with respect to the edge of the pattern to be cut.

Since the point 105 is deduced, the control means 30 generate a read vector information 34 to cause the reading means 5 to move in a fourth path towards the point 105. By default, the learning means 9 are not put into operation. implement, but the operator can control their implementation from the means of voluntary implementation 39 learning means 9. Then the control means 30 generate a reading vector information 37 to cause a displacement of the reading means 5 following a third path to the point 106, the learning means 9 being implemented. During this displacement of the reading means 5, reading information c, c ', d, d', e and e 'are detected and analyzed by the learning means 9 and the recognition means 11 associated with the comparison means 14.18. The format of the pattern M1 is marked, and a dimension of the pattern M4 is marked. Furthermore, the reading information e, e 'is indicative of the presence of a M5 pattern partially located on the carrier device 38 of the print medium 2. It will be noted that, from a single detected dimension of a pattern and from the reference information relating to the potential format and / or the number of patterns, their position and / or their distribution on the printing medium can be deduced by the learning means 9 and the recognition means 11 associated with the comparison means 14,18. It follows that calculation operations are still spared and the reading process can be accelerated without affecting the generation of the cutting program 6 from the learning means 9.

The reading means 5 having covered a dimension of the printing medium 2 limited to one dimension of the carrier device 38, the learning continues in the analogous manner of the technique which has just been stated:

^* ) to point 107 without learning,

^* ) to the point 108 with learning and detection of reading information ff, gg 'and hh' respectively revealing the position and a dimension of the patterns M3 and M2 and the other dimension of M4.

^* ) to point 109 without learning,

^* ) to point 110 with learning and detecting reading information ii 'revealing the other dimension of M2 pattern and e''revealing the presence of the pattern M5.

^* ) to the point 111 without learning, deduced from the knowledge of the first dimension of M2,

^* ) to the point 112 with learning and detection of reading information e, e 'relating to M5, and jj' revealing the other dimension of the pattern M3.

^* ) to point 113 without apprenticeship

^* ) to point 114 with learning and detection of playback information e "'ee""relating to M5.

The entire surface of the print medium 2 accessible by the displacement means 31 of the reading means 5 having been covered, the cutting program 6 is produced and the cutting of the patterns M1, M2, M3 and M4 is performed.

The pattern M5 is partially detected, it is not cut. 5

In FIG. 7, the printing medium 2 is displaced relative to the carrier device 38. The partially detected pattern M5 is placed at the zone boundary accessible by the reading means 5 and by the cutting tool 1. This limit zone can be reduced by a previously set value. The learning continues according to the analogous modalities of the technique that has just been stated:

^* ) to point 115 without learning,

^* ) to point 116 with learning and detection of read information k- k 'relating to a first dimension of M5, *) to point 117 without learning,

^* ) to the point 118 with learning and detection of reading information M 'relating to the second dimension of M5.The learning cycle continues and the presence of patterns M6 and M7 is detected and the pattern M5 is cut, so analogous to the previous statement. The starting displacements of the reading means 5 which are carried out without learning the read information 10, are provided for trajectories intended to bring the reading means 5 towards a starting position of a trajectory from which the reading means 5 are moved with learning read information 10. It is advantageous that these outgoing movements are performed without learning the read information 10 to allow for quick movement of these and to avoid unnecessary calculation operations. However, the device is preferably provided with means 39 for training the learning means 9 to allow the operator if he wishes to control the learning, recognition and / or comparison of the reading information 10 detected during these departing trips.

The device is able to cut a pattern at least one of whose dimensions is greater than the possible area covered by the cutting tool 1. Such a pattern format may or may not be identified as soon as the set information has been entered. The device is able to identify the impossibility of cutting such a pattern in a cutting operation, that is to say without having to move the print medium 2 accordingly. This identification is for example made from the learning operation itself and the detection of the reading information 10 revealing or not an inscription 3,4 following concurrent paths traveled by the reading means 5. Such an identification is preferably associated with the comparison of this reading information with a relative set of information in the format of the pattern to be cut. From the learning modes similar to those just described, such a pattern is detected and the partial cutting operation can be controlled. The support is then moved relative to the mobility means 29 of the cutting tool 1, and learning continues in similar ways to those previously described to complete its cutting.

It will be noted that the learning and cutting modes described in relation to FIGS. 6 and 7 are not exhaustive, but must be considered as revealing of the advantages provided as to the means implemented for such learning and for such pattern cutting. These modalities can be transposed for any reasons to be cut from an implementation of the learning means 9 associated with recognition means 11 and comparison means 14, 18.

A method has thus been described for cutting a plane printing medium around at least one previously printed pattern on this printing medium. The method comprises the preceding step of printing at least one registration by means of a reading of this registration associated with a learning on the basis of this registration which allows the transcription of learning information into control vector information. in mobility of a cutting tool and / or a carrier device of the print medium. The method comprises associating at least the steps of: a) performing a reading of the surface of the print medium from a reading means displacement and / or the carrier device of the print medium on along this surface; b) developing cut data relating to identification information and / or registration framing at least by learning based on the reading information; 7

c) transcriptionally developing a cutting program by identifying a contour (C) to be cut from at least one of the steps of identifying the inscription by comparing the reading information with the definition information and / or identifying a format by comparing the read information with the registration information based on the cut data; and d) controlling the implementation of the mobility means from the vector information of the developed cutting program.

OTHER EXAMPLES OF EMBODIMENTS

In other embodiments, a reading detector 4 mounted on a mobile carriage 150 is not used. As an equivalent, a camera is used for taking a two-dimensional image of the part of the printed medium. arranged on the table. This image is, as is known, constituted by an overlap of pixels arranged according to a two-dimensional stored table. Once acquired, the two-dimensional table is then analyzed based on the method described above. The step of learning the cutting contours is executed by executing a path for detecting characteristic points among the pixels of the two-dimensional table representative of the image of the printed medium. For this, a digital pixel value belonging to the characteristic point detection path is compared such as the brightness or color recorded in each pixel of the table so as to detect the characteristic transitions indicating that the characteristic point detection path in the 2D pixel digital table intersected the image of a dash of a cut mark. An acquisition loop is then executed for the characteristic points of the cutting contours and their assignment to a cutting contour, as well as the two end-of-dimension tests that have been described using FIG. 1 in particular. The production step of a cutting program 164 is identical.

In particular, the 2D imaging camera of a portion or the entire surface of the printed medium may be constituted by a linear array of electro-optical sensors arranged at the loading input of the cutting table 38. When the printed medium is loaded on the cutting table 38, during its course in front of the linear bar, the 2D image of the printed surface is acquired and the learning step can be performed. This avoids the duration taken by the execution of the carriage paths in the embodiment of the learning step of Figure 1 in the strict sense, the numerical analysis of a 2D digital image being much faster.

In other embodiments, the inclination of each of the edges is detected by the recognition of two characteristic points such as the pair of points (a, b, Figure 5). It is thus possible to realize the recognition of polygonal contours whose angular relationship between two adjacent edges is arbitrary.

In other embodiments, the cutting contour detected at the end of the learning step is compared to standard formats of cutting contours. A corrected contour of cut is then selected using the contour of cut whose standard format is the closest to that which has been detected (or learned) and the corrected contour of cut is centered on the outline of cut detected (or learned ).

Claims

1 - Process for cutting a flat printing medium around at least one previously printed pattern on this printing medium with cutting marks associated with said at least one pattern, the method being of the kind in which a step of cutting training by detection of cutting marks and a step of producing a cutting program of said at least one pattern, which program is subsequently executed by a cutting machine, characterized in that it consists in: • detecting ( 155) at least one sequence of characteristic points of the geometry of at least one cutting contour on the basis of the cutting marks;

Assigning (156) each detected characteristic point to at least one cutting contour; • search for characteristic elements (edge of contour, corner of contour) of said contour on the basis of said characteristic points, then

Translating (164) the detected cutting contour into vector information for moving a cutting tool to generate said cutting program of at least one cutting contour. 2 - Process according to claim 1, characterized in that, the cutting contour being of polygonal shape, it consists of:

• determining the orientation of at least a first edge of the contour by detecting at least two characteristic points (A1, A2);

• determining an edge adjacent to a detected previous edge by detecting at least one feature point (A3) of said adjacent edge.

3 - Process according to any one of claims 1 and 2, characterized in that it consists in determining at least one origin point (AO) of at least one path for detecting characteristic points of determined dimensions on the database configuration and / or detection of a characteristic element of the printed medium such as an edge or a corner of the support.

4 - Process according to any one of claims 1 to 3, characterized in that the contour providing at least one internal margin determined (223) with the useful printed interior surface (204) of the pattern, in order to detect a characteristic point, it consists in determining said path of detection of characteristic points in the internal margin provided and in detecting during the path a transition of a characteristic detection, such as the color or print brightness between the margin and the printed mark.

5 - Process according to claim 4, characterized in that it comprises a step for detecting a wedge by means of the detection of at least one characteristic point on a next adjacent edge (205) to the preceding detected edge (207) while performing searching for characteristic points in the inner margin (223) at said previous detected edge (205).

6 - Process according to any one of claims 4 or 5, characterized in that, to acquire at least one characteristic point of a contour, it consists in determining said characteristic point detection path in the inner margin (223) of said contouring by path segments (227; 231; 233; 235) of predetermined dimensions to reduce the acquisition time based on contour contour format data.

7 - Process according to claim 6, characterized in that, the relative orientation of the adjacent edges being predetermined, it consists in associating the known relative orientation of the edge being detected with the determined absolute orientation of the previous detected edge (207). ) to determine the direction of the inner margin (223) and with the detection of a characteristic point (A3) on the edge being detected (205) to derive the directional coefficients of the line representative of the edge being detected (205).

8 - Process according to claim 6, characterized in that, if a characteristic point is detected on a previous detected edge in a contour, a confirmation and / or reduction step (234; 238) of the uncertainties on the coefficients is performed. directors of said straight line representative of the previous detected edge (232; 236).

9 - Process according to any one of claims 4 to 8, characterized in that it consists in determining the point detection path characteristics of at least one cutting contour so as to progress in a first direction (Y) by acquiring the cutting contours one after the other:

- when an extension limit of the medium printed in said first direction has been reached (239), to choose a new origin point (244) at the beginning of said first direction (Y) beyond the extension in a second direction (X) of the detected contour having the smallest extension in said second direction out of the contours detected during the previous progression in said first direction as long as an extension limit in said second direction has not been reached and to be reiterated the path progressing so as to acquire at least one new contour not yet detected.

10 - Process according to any one of claims 1 to 3, characterized in that it consists in determining the detection path of characteristic points (a, a ') of all the cutting contours arranged along a first direction then, when the end of the extension of the first direction is reached (104), to cause a progression of the path in a second direction and then to resume the detection sequence of the characteristic points (c, c ') of the cutting contours disposed in said first direction and repeat the operation as the end of the extension of the printed medium in the second direction is not reached. 11 - Process according to any one of claims 9 or 10, characterized in that, when the printed medium is greater in said second direction than the extension in this direction of a table receiving the printed medium, it also comprises a a step of, when the feature point detection path has reached the end of the extension of the printed media receiving table in said second direction, controlling an advance of the printed medium on said table receiving the printed medium, and then performing a step of detecting a new origin position selected at the beginning of said second direction and on the remaining surface still unrecognized from the printed medium; and to resume the process of detecting the sequence of the characteristic points on the not yet completely recognized cutting contours.