ES2353126T3 - FILLING A ZONE OF AN IMAGE MARKED ON A MATERIAL WITH THE HELP OF A LASER. - Google Patents

Abstract

Method of filling an area of an image by marking on a material with the aid of a laser beam, comprising: the conversion of the area of the image to be marked on the material with the aid of a laser beam into a set of positions: defining progressively smaller contours of the image area, and converting each defined contour into a set of separate positions that can be used to direct the laser beam; and marking the material with the help of the laser beam, guiding it conveniently so that it stops in the different positions and so that it moves between them.

Description

 5

BACKGROUND

 Existing laser printers to mark products use software to fill solid areas of a graphic image, such as company logos, using a cross-hatch. With such cross-hatching, many short vectors or lines are created that require a laser to be repeatedly activated and deactivated. The term "vectors" refers to the control of a laser beam in order to activate and deactivate it to form lines. Repeated laser switching shortens its life. A certain delay is introduced while the vectors are made, the mirrors are positioned and the laser beam is activated and stops for each vector. 20 Therefore, cross-hatching can create a texture that conflicts with the image being marked.

SUMMARY 25

 According to a first aspect of the present invention, there is provided a method of filling an area of an image by marking on a material with the aid of a laser beam, comprising: the conversion 30 of the area of the image to be marked on the

material with the aid of a laser beam in a set of positions progressively defining smaller contours of the image area and converting each defined contour into a set of separate positions that can be used to direct the laser beam 5; and mark the material with the help of the laser beam, guiding it conveniently so that it stops in the different positions and so that it moves between them.

 According to a second aspect of the present invention, there is provided a system for filling an area of an image by marking on a material with the aid of a laser beam, comprising: a laser that can be operated to produce the laser beam, a optical assembly that can be used to focus and direct the laser beam, as well as one or more machines that can be used to convert the area of the image to be marked on the material with the help of a laser beam into a set of positions progressively defining contours small of the area of the image and converting each defined contour into a set of separate positions that can be used to direct the laser beam, and mark the material with the help of the laser beam controlling the laser and the optical assembly to direct the laser beam, 25 so that it stops at the different positions and moves between them.

 According to a third aspect of the present invention, a computer program is provided that can be used so that one or more machines perform 30 operations including the filling of

an area of an image marking on a material with the aid of a laser beam, comprising: conversion of the area of the image to be marked on the material with the aid of a laser beam into a set of positions progressively defining smaller contours 5 from the area of the image and converting each defined contour into a set of separate positions that can be used to direct the laser beam; and marking of the material with the help of the laser beam, guiding it conveniently so that it stops in the 10 different positions and so that it moves between them.

 The system may comprise a software application that converts graphic images created by graphic applications to a format that can be effectively printed on the product with the aid of a laser printing system. In order to convert the graphic images, the application uses concentric silhouettes to fill in the areas of the image to be marked (which can be dark or 20 light areas).

 The software application and the laser printing system can provide several advantages. The systems and techniques described can be used with matrix laser printers, vector laser printers or other types of laser printers. With the software application the user is allowed to select and adjust the resolution of the graphic images in numerous ways in order to obtain the intended application. For example, with the software application, the user can select the location and the

density of the laser point. Also, said application does not require a special graphic program and can be used with many of the third-party graphics generation applications.

 The image may be constituted by at least 5 by a marking zone and at least by an unmarking zone. The different marking zones are composed of a set of essentially concentric silhouettes. Each of said silhouettes comprises a set of points. The laser is capable of generating a laser beam that stops at each point, according to a programmable period of permanence, in order to alter a visible optical characteristic of the product. For example, the period of permanence can be configured so that the laser beam moves between points without altering any visible optical characteristic of the product between points, the laser beam stops at each point longer than the travel time between consecutive points and said laser beam strikes the material until the image is fully formed in the product. Alternatively, the residence period can be set so that the laser beam is similar to that of a vector laser printing system.

 The conversion of the image into a set of 25 positions may involve identifying a set of dots that resist the bordering pixels of a marking area of the image, so that with said set of dots a contour of the marking zone is formed, eliminate border pixels with respect to the definition of contours for the zone of

marking, re-carry out the identification and elimination until all the pixels of interest of the marking area have been considered, as well as determining the positions from the identified points. 5

 The identification of the set of points may involve identifying points extracted from an image space that has a higher density / resolution than that of the image. The identification of the set of points may involve identifying the 10 points based on a certain programmable tolerance value. The removal of bordering pixels may involve removing pixels based on a programmable contour progression factor. The pixels of interest can be defined by a programmable silhouette-only configuration. Likewise, the determination of the positions may involve determining the positions from the identified points based on a programmable step size. twenty

 The image can be generated from a source image based on a programmable intensity threshold. The process may also involve initially removing borderline pixels from the marking zone based on a programmable previous erosion value. The marking of the material with the help of the laser beam may involve continuously guiding the laser beam according to the points, in an order that corresponds to the progressively smaller contours. This can be done using a laser staggering and repeating printer and that

present a period of variable permanence, which can also be used to mark illuminated points in the material preventing the alteration of a visible optical characteristic of the material in the areas focused by the laser beam between said illuminated points.

 Additionally, the marking of the material with the aid of the laser beam may involve directing said beam to a product and its material in motion according to the points, in an order that corresponds to the 10 progressively smaller contours and that corresponds to the times in those that progressively smaller contours enter the laser print opening. Likewise, progressively smaller contours can comprise 15 contours that overlap (since they can originate when approximating ideal contours when determining positions to be marked with the help of a laser).

 In the accompanying drawings and in the description indicated below, the details of one or more forms of implementation are presented, in which the systems and techniques of the present invention are described in combination with a continuous wave laser arranged in a system of laser printing of staggering and repetition and having a variable period of permanence. It should be noted that the imaging systems and techniques described can also be applied to other approaches to laser printing, for example vector laser printing. Additionally, for a greater understanding of the description, the terms zones

"dark" and "bright" are then used to describe "marked" and "unmarked" areas, although it should be understood that a marking zone can be dark or bright, just as an unmarked zone can also be Dark or bright, in 5 any application.

 From the description and drawings, as well as from the claims, additional features and advantages are revealed.

 10

BRIEF DESCRIPTION OF THE DRAWINGS

 A side view of an example printing system is shown in Figure 1A.

 A cross-section 15 of the printing system of Figure 1A is shown in Figure 1B, in a view looking down the printing system.

 Figure 2 illustrates the printing system of Figure 1A forming a zone of printing on a product.

 Figure 3A shows a side view of a printing system used in combination with a production line that temporarily stops a product in front of said printing system.

 A side view of a printing system used in combination with a production line that continuously moves products in front of the printing system is shown in Figure 3B.

 A plan view of the printing system of Figure 3B used in combination with a production line that continuously moves products in front of said printing system is shown in Figure 3C. 5

 An example of an optical assembly for use with the printing system of Figure 1A is illustrated in Figure 4A.

 Figure 4B shows a side view of a plurality of mirrors of Figure 4A 10 configured to guide a laser beam, generated by the printing system, from one point to another in the product in which a code must be formed.

 Figure 4C illustrates the relationship between an optical assembly and the housing of the printing system 15 of Figure 4A.

 Figure 4D illustrates the non-linear nature of a lens that is used in the optical assembly of Figure 4A.

 A support of Figure 20 4B is illustrated in Figure 4E which allows the rotation of an output element of the printing beam of the system with respect to the housing of said printing system.

 Figure 5A shows a side view of a print beam that affects a point of the material in which a stain must be formed.

 Figure 5B shows a perspective view of a print beam that affects a point of the material where a stain should be formed. 30

 Figure 5C shows a side view of a material, once the print beam has generated a stain.

 A perspective view of a material is shown in Figure 5D, once the print beam has generated a spot.

 An original image, for example a bitmap, is illustrated in Figure 6, which the user intends to mark on a product or on the container of said product with the aid of a laser printing system, such as that of the figure 1A.

 Figure 7 illustrates a converted image that must be marked on a product with the aid of a laser printing system, such as that of Figure 1A.

 An example of image printing system 15 is illustrated in Figure 8, comprising a data processing machine, a laser printing system and the product to be marked.

 Figure 9 illustrates a technique that uses concentric silhouettes to fill in a graph that must be marked.

 An example of an image loaded in the software is illustrated in Figure 10A.

 The Image Parameters dialog box is illustrated in Figure 10B. 25

 Figure 10C illustrates a black image displayed against a dark gray background and a result box.

 An additional example of a set of silhouettes is depicted in Figure 10D. 30

 An example technique that software can use to form a silhouette around a dark area in an original bitmap image is illustrated in Figure 11.

 An example of two 5 pixels of the dark margin (shaded area) of the original bitmap, addressed by points of higher software resolution, is illustrated in Figure 12.

 In figure 13A, 16 line segments associated with their original pixel are illustrated, as labeled.

 Figure 16B illustrates a 16-bit array that can designate the 16 line segments of Figure 13A.

 Figure 14A illustrates the possible 15 line segments and directions that may surround a pixel of the original image.

 In figure 14B sixteen possible line segments and their corresponding addresses are illustrated.

 An individual new point 20 and eight possible directions are illustrated in Figure 14C.

 Figures 15A to 15D illustrate 256 possible combinations of line segment formation for 256 possible combinations of nine pixels of the original image. 25

 Figure 16 shows a series of line segments that are part of a silhouette.

 An example of a technique for forming a silhouette and for generating positions that define laser marking is illustrated in Figure 17. 30

DETAILED DESCRIPTION

 The present application refers to a printing system for printing an image on a surface, for example a surface of a product (for example, the product article, its packaging, a label, etc.) located adjacent to the printing system . The printing system comprises a laser to generate a print beam. An optical assembly guides said print beam from one position to another. 10 The printing system may comprise an electronics to adjust the residence time of the print beam in each position. Said residence time can be adjusted so that the print beam illuminates each position forming a stain. fifteen

 The different positions can be arranged so that the spots formed generate an image or graphic, for example a company logo or a registered trademark. It is also possible to arrange the positions to form symbols or codes, which may be part of an image or be independent of it. The symbols may be available in word processing programs, for example alphanumeric symbols or any other symbol used to identify a batch of products, a date, etc. A sequence or code to be printed may be constituted by said type of symbols and may be legible text, such as a product name or an identifier. It is not necessary that the codes to be printed are alphanumeric and may comprise symbols that are not generated by the codes.

Typical word processing programs. For example, the images, symbols and / or codes generated may comprise barcodes and complex graphic characters.

 An example of 5 printing system 10 for printing on a product 22, arranged adjacent to said printing system 10 is illustrated in Figures 1A and 1B. A side view of the printing system 10 is shown in Figure 1A, while in Figure 1B shows a top view of a cross section of the printing system 10. Said printing system 10 comprises a laser 12 to generate a printing beam 14. Many types of lasers can be used in the printing system. Since the residence time can be increased in order to compensate for a reduced laser power, a low power laser can be used in the printing system. For example, laser 12 may be an air-cooled CO2 laser. In some cases, the laser can be a 50 W laser 20, a 30 W laser, a 10 W laser, or less power.

 The printing beam 14 of the laser / energy source 12 is guided through an optical assembly 18 and affects a material 20, for example a material 25 used for packaging the product. As will be described in more detail below, the time during which the beam 14 strikes the material 20 can be adjusted so that the beam 14 generates a spot that must be formed on said material 20. 30

 The optical assembly 18 comprises components for altering the printing beam 14. Such components can be controlled to guide the printing beam 14 from one position to another, so that a spot is created in each of the positions. The spots, or illuminated dots, can be arranged to form one or more images or symbols on the material 20 of the product 22 using the techniques described above.

 The printing system 10 also comprises 10 an electronics 26 that communicates with the laser / power source 12 and the optical assembly 18. Said electronics 26 may comprise one or more processors to be functional for the printing system 10. As suitable processors Although this is not limited, microprocessors, digital signal processors (DSP), integrated circuits, integrated circuits for specific applications (ASIC), logic gate arrays or switching matrices can be used. Said electronics 26 may also comprise one or more memories for storing instructions that one or more processors must execute and / or for storing data generated during the operation of the printing system 10. As suitable memories, although this is not limited, they can be use RAM or read-only electronic memories (for example, ROM, EPROM or EEPROM).

 The electronics 26 control the operation of the laser 12 and the optical assembly 18. For example, the electronics 26 can control the optical assembly 18

to adjust the direction of the print beam 14, the time interval during which the print beam 14 stops at the position of the material 20 in which a spot must be formed, the travel speed of the print beam 14 5 between each position in which the beam stops, the size of the illuminated dots to create visually recognizable images / symbols.

 The electronics 26 can optionally communicate with a user interface 30. Said 10 user interface 30 may be separated a certain distance from the housing 16, be connected to said housing 16 and / or be detachable from said housing 16. The user interface 30 can be a portable device. A suitable user interface 80 15 may comprise an alphanumeric keyboard and an indicator. The user interface 30 can be used to program the electronics 26 and / or to configure printing parameters. For example, said user interface 30 can be used to manually control the time during which the print beam 14 stops at each of the positions of the material 20, the size of the spots used to form a simple observable symbol view, the type and / or sequence of symbols to be formed, etc. Said user interface 30 can also be used to manually activate the printing system 10. For example, the user interface 30 may comprise a printing key that activates the printing action on the material 20 30 by the printing system 10 .

 The electronics 26 can also communicate with one or more sensors 31. Said sensors 31 can provide the electronics 26 with information about the products on which the printing system 10 should print. For example, the 5 sensors 31 can signal the position of a product 22 with respect to the printing system 10, the direction of travel of a product 22, the moment at which a product 22 stops, or the moment at which said product 22 is in 10 a correct position to print on it. As suitable sensors 31 (described below), a speed sensor can be used, although not limited, to detect the speed and / or direction of a product 22 and a position sensor 15 to signal the moment when a product 22 It is arranged in front of the sensor 31.

 The printing system 10 comprises an output element of the print beam 32, through which the print beam 14 leaves the housing 16. Said output element of the print beam 32 can be as simple as an opening in the housing 16 or a fixed window arranged in said housing 16. In another embodiment, the output element of the print beam 32 can be moved relative to the housing 16, as indicated by the arrow labeled A. In said form of embodiment, the printing beam 14 can be manually directed towards a particular position of the material 20 by manipulating said output element of the printing beam 32. 30

 An example of the printing system 10 is illustrated in Figure 2 by creating a printing zone 34 on a product 22. Said printing system 10 may comprise components for defining the printing zone 34 in the material 20. For example, the system The printing system 10 can project a rectangle on the material 20, as illustrated in Figure 2. The printing system 10 forms the code symbol inside the printing area 34.

 During operation of the printing system 10, the printing area 34 can be printed automatically or can be controlled by an operator. Said operator can adjust the output element of the beam 32 so that the printing area 34 conforms to the desired location of the material 20. Then, through the user interface 30 the printing is activated inside the area of printing 34. Consequently, the operator of the printing system 10 can select in which position the printing system 10 will print a code on the material 20, making sure that the printing area 34 appears at the desired printing location. As suitable printing zone marks, although this is not limited, one can use marks in the four corners of a printing area 34, a mark in the center of the printing area 34 and a dashed line around the printing area. print 34.

 In one embodiment of the printing system 10, the electronics 26 controls the size and 30 the geometry of the printing area 34.

Consequently, the electronics 26 are capable of adapting the size and shape of the symbols to be printed on the material 20. For example, when an unusually large code needs to be printed on the material 20, the electronics 26 can increase the printing area 5 34 so that the code conforms entirely within the printing area 34. Therefore, an increase in the size of the code does not imply a wrong positioning of the code in the material 20. 10

 A side view of the printing system 10 operating in conjunction with a production line 36 that stops the product 22 temporarily in front of said printing system 10 is illustrated in Fig. 3. The printing system 10 can print on a product 22 which it is not in motion or in a package arranged on the production line 36 that displaces the product 22 in relation to said printing system 10. The printing system 10 of Figure 3A communicates with a print trigger 20, which detects the moment at which one of the products 22 is positioned in front of said printing activator 38. A suitable printing activator 38 comprises a device that generates a ray of light. Said device may be arranged adjacent to the production line 36, so that the product 22, which travels through the production line 36, interrupts said light beam at some point. The printing system 10 can control the device to determine if the product 22 30 has interrupted the flow of light. The activator of

Printing 38 can be arranged so that when the mechanism is triggered, the product 22 is correctly positioned for printing the product 22. Alternatively, the print trigger 38 can be located so that when the mechanism is triggered, a product is generated. Temporary delay before product 22 is correctly positioned for printing product 22.

 The printing system 10 can also communicate with a stopping mechanism 40, which stops 10 each product 22 in front of the printing system 10. When the production line 36 is working, the stopping mechanism 40 is removed, allowing the products 22 they move along said production line 36. The displacement can originate from one or more mechanical forces or from one or more natural forces, such as gravity. Once the product 22 has exceeded the stop mechanism 40, said stop mechanism 40 returns to its place to block the next product 22.

 During operation of the printing system 10 illustrated in Figure 3A, the products 22 move past the printing system 10 on the production line 36. 25 The printing system 10 controls the printing trigger 38 to determine the timing wherein a product 22 passes in front of the printing trigger 38. The printing system 10 expects a preset delay so that the product 30 is pressed against the stop mechanism 40

and then print the symbols on the packaging. Consequently, the product 22 is not moving while the printing system 10 prints the code on the packaging.

 Once the code has been printed, the printing system 5 activates the stopping mechanism 40 so that the product 22 is able to move again. The printing mechanism controls the printing activator 38 in order to find a separation space between products 22. 10 Once a separation space has been found, the printing system 10 activates the stop mechanism 40 to stop the next product 22 and again controls the print trigger 38 in order to detect the moment in the next product 22 pass 15 to be placed in front of the print trigger 38.

 A printing system 10 in conjunction with a production line 36 is illustrated in Figures 3B and 3C, which continuously moves the products 22 in front of the printing system 10. The 20 products 22 may be uniform or spaces may occasionally exist in the line. The printing system 10 communicates with a print trigger 38 and with speed sensor 42. Electronics 26 (Figure 1B) can use signals 25 from speed sensor 42 to determine the speed and direction of products 22 in production line 36. As suitable speed sensors, although this is not limited, encoders and 30 "resolver" devices can be used.

 In the configuration of the printing system 10, with administration rights, the distance between the printing system 10 and the printing activator 38 can be entered in the electronics 26. In an alternative embodiment, the printing activator 38 is connected to the housing 16 in order to obtain a known fixed value distance between the printing trigger 38 and the printing beam 14. In this embodiment, the electronics 26 know the distance value, so it is not necessary to Your introduction

 During operation, the printing system 10 controls the printing activator 38 to establish the moment in which a product 22 is arranged in front of the printing activator 38. At the moment in which this occurs, that is to say when a product 22 is located in front of the print trigger 38, the printing system 10 determines the speed of the product 22 on line 36 and uses that speed to establish a time delay 20 of code position. Said temporary code position delay is set such that the code is printed at the desired point of the product 22. A suitable procedure for determining said code will be described later. Once the temporary code position delay has elapsed, the symbols are printed while the product 22 moves along the printing system 10.

 Once the code has been printed, the 30 print trigger 38 is in a position to

determining the moment when the product 22 has exceeded said printing activator 38. In one embodiment, the printing activator 38 is continuously checking the moment when a new product 22 is in front of the printing activator 5 38. Such as shown in FIG. 3B, a product 22 can trigger the print trigger 38 while the printing system 10 is printing on another product 22. For this reason, the printing system 10 may follow the temporary delay 10 of one of products 22 while printing on another product 22. To deal with such scenarios, standard multitasking programming can be used.

 The printing system 10 can be used with 15 other types of production lines 36. For example, some production lines 36 comprise a labeling station for applying a label to a product 22. A typical labeling station comprises an electronics for determining the moment 20 of applying the label on a product 22. The printing system 10 can communicate with the labeling station and can print the code on each label after its application on the product 22. The electronics arranged in the station 25 of Labeling can take care of triggering code printing. For example, when the electronics of the labeling station detects that a label has been applied, said electronics can transmit to the printing system 10 a signal 30 indicating that the code must be printed.

 A top view of an optical assembly 18 of the printing system 10 is illustrated in FIG. 4. The optical assembly 18 comprises a laser source 12 for generating the printing beam 14. Said printing beam 14 passes through a first divergent lens 5, whose function is to expand the printing beam 14. The optical assembly 18 also comprises a light source of a printing zone 52 to generate a printing beam of zone 53, which passes through a second divergent lens 10, whose function is to expand the beam printing zone 53. Although the printing beam 14 and the zone printing zone beam 53 are represented as if they occur simultaneously, the electronics 26 (Figure 1B) can cause them to be generated independently. In addition, the zone 53 printing beam is optional and it is not necessary to include it in the optical assembly 18.

 The print beam 14 and the zone print beam 53 are combined in a beam combiner 56. The combination of said beams passes through a converging lens 58, whose function is to collimate the beams before they change direction in a reflector 60 Next, the combination of said beams reaches a plurality of mirrors 62, whose function is to reflect the combined beams towards a second converging lens 63, which concentrates the combined beams. Then, the combined beams pass through a protection window 64 before reaching the product 22.

 Since in Fig. 4A a top view 30 of the optical assembly 18 is shown and the mirrors 62 are

arranged one above the other, the arrangement of the mirrors 62 is not apparent from said figure. In order to clarify the arrangement of said mirrors, a side view of the optical assembly 18 is shown in Figure 4B looking through 5 of the protection window 64. The combination of said beams 14, 53 reaches the mirrors 62 coming from the left, as indicated by the arrow labeled "A". Beams 14, 53 are reflected in a first mirror 66 down in the direction of a 10 second mirror 68. Next, the combination of said beams 14, 53 is reflected in the second mirror 68, leaving the page.

 As shown in Figure 4C, one or both mirrors 62 can be coupled to one or more 15 actuators 70, in order to be able to move said mirrors 62. As suitable actuators 70, although this is not limited, micromotors can be employed. The electronics 26 (Figure 1B) are responsible for controlling the actuators 70 in order to guide the beams 14, 53 20 to form symbols and the printing area 34 in the package. For example, if the shape of the printing area 34 is rectangular, the zone printing beam 53 could draw a rectangle around the printing area 34 at a speed such that said rectangle was apparently solid for the human eye, or well at a speed of about 100 cycles / second.

 The second converging lens 63 of Figure 4A may be a nonlinear lens. Figure 4D illustrates the second mirror 68 in a first and a

Second positions In the first position, the angle formed by the print beam 14 with an axis of the lens is α, while in the second position it bends to 2α. With the second mirror 68 in the first position, the print beam 14 strikes the product 22 at a distance C from the lens axis. However, due to the non-linear nature of the lens 63, the second mirror 68 being in the second position, the printing beam 14 does not impact the product 22 at a distance 2C from the lens axis, 10 despite the fact that the angle value has been increased to 2α. The nonlinear nature of the lens 63 causes a lack of proportionality between the displacement of the mirror 68 and the displacement of the printing beam 14. 15

 The electronics 26 (Figure 1B) may comprise logic to correct the non-linearity effect of the second converging lens 63. Accordingly, such logic would cause the second mirror 68 to increase the angle value to a value greater than 20 to 2α, in order of moving the print beam 14 a distance 2C. The correction logic can be developed from optical theoretical equations that provide a relationship between α and C for the second converging lens 63. Alternatively, the correction logic can be developed from experiments performed to determine the relationship between α and C. This correction logic eliminates the need for an expensive and large-sized F-theta (F-θ) lens, which is usually used to correct nonlinearity. By

consequently, by means of said correction it is possible to reduce the size and cost of the printing system 10.

 The effect of spherical aberration can be corrected by varying the period of permanence. For example, said period of permanence can be increased if the effect of aberration is revealed in product 22.

 During operation of an optical assembly 18 comprising a light source of a printing zone 52, said light source of the printing zone 52 is activated and the laser 12 is deactivated. The mirrors 62 are moved so that the printing area 34 is formed in the product 22. If the symbols must be formed in the packaging, the light source of the printing area 52 is disconnected, and the energy source / Laser 12 is connected until the symbols are formed. Once the symbols have been formed, the energy / laser source 12 can be disconnected and the light source from the printing area 52 can be connected 20 in order to continue with the conformation of the printing area 34.

 As described above with reference to Figure 1B, the printing system 10 may comprise an output element of the printing beam 32 that can be displaced with respect to the housing of the apparatus 16. Figures 4C and 4E are shown. the mechanical arrangement that allows said displacement of the output element of the print beam 32. The frame 76 shown in Figure 30 4C supports the output element of the beam of

print 32 inside the housing 16. A support 78, disposed between the frame 76 and the output element of the print beam 32, allows said output element of the print beam 32 to move relative to the frame 76. In Figure 4E 5 shows a lateral cross-section of the support 78 looking along the printing beam 14. The printing beam 14 crosses the support 78 (Figures 4C and 4E) along the axis of rotation 80 permissible by the support 78 (figure 4E), is reflected in the 10 mirrors 62 (figure 4C), and crosses the end of the outlet element 32 (figures 4C and 4E). For this reason, the displacement of the output element of the print beam 32 in relation to the frame 76 does not change the position of the print beam 14 in relation to the support 78.

 As illustrated in Figures 4C and 4E, the mirrors 62 and the actuators 70 are coupled to the output element of the printing beam 32. Accordingly, the mirrors 62 and the actuators 70 are displaced with the output element of the beam printing 32 as said output element of the printing beam 32 moves relative to the housing 16. Also, a part of the first mirror 66 (Figure 4B) is positioned along the axis of rotation of the support 80 ( figure 4E). For this reason, the displacement of the output element of the print beam 32 does not change the angle of incidence between the print beam 14 and the first mirror 66. Therefore, when the output element 30 of the print beam 32 is displaced with relation to

housing 16, the first mirror 66 continues to focus the print beam 14 towards the same part of the second mirror 68, and the print beam 14 continues to exit the housing 16 through the same site of the protection window 64. The rotational capacity of the output element 5 of the print beam 32 relative to the housing 16 allows the print beam 14 directed through the output element of the print beam 32 to be oriented towards different points of the product 22. 10

 As described above, the print beam 14 forms a plurality of spots in various positions of the product 22, remaining in each position until one of its optical characteristics is altered. In order to illustrate it, 15 in figures 5A to 5D the formation of a stain on a product 22 is represented by removing the ink layer of said product 22. In figures 5A and 5B the printing beam 14 is represented by affecting a particular position of the material 22 before a spot 83 (Figure 5C) is formed on the material 20. The material 20 comprises a substrate 82, for example paper. An ink layer 84 is formed on said substrate 82. The ink layer 84 may comprise various different types of ink, as well as various different colors, as is apparent from the labels of many commercially available products. . The material 20 illustrated in Figure 5A comprises an additional layer 86. Said additional layer 86 represents one or more layers 30 that are often arranged above the layer of

84 ink in product packaging. For example, many materials 20, such as those in dog food bags, comprise a layer of wax on the substrate 82 and the layers of ink 84.

 In Figures 5C to 5D the material 20 5 is illustrated after the stain 83 is formed in a particular position of the material 20. The time during which the print beam 14 remains in said particular position is adjusted so that the beam of print destroy the ink layer 84 and the additional layer 86 10 of the material 20 without burning the substrate 82. Accordingly, the substrate 82 is visible in the particular position of the material 20. The ablation time of an ink layer 84 typically comprises between 100 and 500 μs. fifteen

 The time to form the stain 83 is often a function of the materials 20 existing in the layers. For example, the additional layer 86 may be a layer of wax that protects the packaging and gives it an attractive appearance. The formation of a stain 83 through said type of layers often requires more time than only through an ink layer 84.

 The present application comprises adjusting the residence time of the printing beam 14 in a position in order to form a spot in said place. In some cases, the residence time is greater than 50 μs, for example 100 μs, 200 μs, 50-50,000 μs, 100-500 μs or 200-500 μs. In some cases, the diameter of the stain is less than 400 μm, less than 30 250 μm or less than 170 μm.

 The systems and techniques described above in relation to Figures 1A to 5D are illustrative only. The systems and techniques described below, which refer to the use of concentric silhouettes to fill a graphic image marked with the help of a laser, can be used with any type of laser printing system, such as those provided by Markem of Keene, New Hampshire and LaserInk Corporation of San Diego, California. For example, the laser printing system 10 used can use the systems and techniques described in US Pat. UU. No. 6,791,592, published on September 14, 2004 and entitled "Printing a Code on a Product", the patent application of US 15. UU. No. 10 / 890,069, filed on July 12, 2004 and entitled "Laser marking User Interface", the US patent application. UU. No. 10 / 693,356, filed October 24, 2003 and entitled "Low 20 Angle Optics and Reverse Optics" (reduced angle and inverted optics), and US patent application. UU. No. 10 / 741,930, filed on December 19, 2003 and entitled "Striping and Clipping Correction." 25

 An original graphic image 600 is illustrated in Figure 6, which a user intends to mark on a product or on the product container. Said image 600 can be saved in a file as a bitmap. A graphical application described below may convert dark areas of the

original image 600 in a set of concentric silhouettes, as shown in Figure 7, which are arranged neatly as points where a laser printing beam can be concentrated.

 Figure 7 illustrates a converted image 5 700 that must be marked on a product. The graphic application uses concentric silhouettes 702A, 702B, 700C of designated points (each nth point) in order to fill in dark areas of the original image 600. These designated points and 10 silhouettes 702A to 702C can be separated from each other by a reduced space and the actual printed image may be small (for example, a quarter of an inch), so that the real dark area of the printed "A" seems essentially solid for human eye 15. Such silhouettes 702A-702C follow the contour of the image and reinforce its visual appearance.

 The silhouettes 702A-702C can be formed in a product with the help of a laser, possibly using steps and repetition processes and varying the period of permanence, as described. The laser can be operated in a continuous wave mode and can remain on between designated points and between silhouettes 702A-702C. 25 By doing so, you can reduce the size of the data set of the converted image 700 and the number of times the laser needs to be turned on and off. Among other benefits, by leaving the laser on until the image is fully formed, 30 delays can be eliminated than otherwise

would arise between consecutive vectors used in cross-hatching. However, as mentioned above, the concentric silhouettes approach to mark an image on a product can also be used with vector 5 laser printers.

 An example of image printing system 820 is illustrated in Figure 8, which comprises a data processing machine 800, a laser printing system 810 and a product 22 to be marked. The data processing machine 800 can be a personal computer (PC), a laptop or any type of computer equipped with a processor, a memory, a hard disk, a screen and input elements, for example a keyboard and a computer. mouse. The data processing machine 800 may comprise one or more graphic software applications 806, for example Microsoft Paint ™, a graphic software based on Windows® 802 (hereinafter "software 802"), and an additional software application 20 804, whose function is to transfer the laser images to the laser printing system 810. The software application 804 can be a device interface application tailored for a family of laser printing products, for example the Expert ™ application, available from Markem. of Keene, New Hampshire and LaserInk Corporation of San Diego, California. The graphic software application 806 can be used to create and edit images (for example, 30 bitmaps). 802 software can convert a

original image, such as image 600, in an image that can be printed, for example image 700, which can be stored locally in the printing system 810. The 802 software can be stored on a machine-processable medium, such as a hard disk, a 5 memory or a disk. The 802 software can be integrated into a printer driver, for example a Microsoft Windows® printer driver. It should be noted that the described functional operations can be integrated in multiple software products 10, such as those described, or in a single software product, and can also be used with multiple types of operating systems.

 The 810 laser printing system can be a SmartLase I, 110, 130 or any available laser from 15 LaserInk Corporation of San Diego, California. The 810 laser printing system can have a 2 ”x4" laser aperture, a dot size of 0.008 "and a minimum step time of 150 μs. The laser wavelength and its power determine the materials that can be marking with images The 820 laser-based image printing system can use 802 software to mark any symbol, code, sequence, logo, image or design on a product 22. For example, the 820 system can successfully mark logos of company, for example Ford and Volkswagen, Asian characters, such as Chinese and Japanese characters, special symbols, such as recycling categories, etc.

 Additionally, the 802 system is capable of using a user interface system, so

that in a computer a first software application creates and edits sources, said computer sends the sources to the electronics of a laser, and said electronics uses said sources to convert the text data into images that the laser can print. A second application on the computer can create and edit the bitmaps of the menu screens. The computer can transmit said bitmaps to the user interface system for display. A third application on the computer can create and edit a mapping of the keyboard functions for the user interface. The computer can send said mapping of the keyboard functions to the user interface system. A user can use said user interface to edit the images that the laser must print and to control its operation.

 Figure 9 illustrates a concentric silhouettes technique to fill a graphic that must be marked with the help of the 820 system in Figure 8. The user prepares an image using an 806 graphic application. Microsoft Windows® is compatible with various graphic formats and programs to manipulate images. Users can select from dozens of applications, for example Adobe Illustrator®, Paintbrush and Microsoft Paint ™, to capture, create and manipulate images. Most graphic applications, such as Microsoft Paint ™, can save and export files in 30 bitmap (.bmp) format. Any image I can

displayed on a PC screen can be captured and saved in this ".bmp" format with Microsoft Paint ™. The user can use many graphic applications to manipulate the scale / resolution of bitmap images. Examples of this are Irfan View, a shareware application available for download at the Internet address www.irfanview.com, and Microsoft Paint ™.

 If the user opens the 802 software, which can be started with a dialog window to select the file, you can navigate to the file that includes the desired image and select it. In step 900, the 802 software receives the selected original image that must be marked with the aid of a laser. The 802 software can display the contents of the selected file as a dark and bright bitmap (ie, black and white or monochrome), as shown in Figure 10A.

 An example of an image 1001, loaded in the 802 software is illustrated in Figure 10A. With the 20 horizontal and vertical rules 1009, it is possible for the user to estimate the size of the image to be marked. The scale of rules 1009 can be based on the size of the opening (described above). The 802 software expects to receive a Windows® 25 bitmap with a “.bmp” file extension and expects the bitmap to be conveniently scaled as desired by the user. The user can calculate the desired resolution knowing the value of the total laser aperture, which can contain 4096x4096 addressable points.

will be described later), and the largest image that the user can process with some graphic applications is 1024x1024 pixels. Generally, the best results are obtained starting with the highest resolution and using the minimum output scaling 5.

 If the original image is in color, at step 905, the 802 software can convert it to monochrome. Specifically, the 802 software can divide the original image into zones that must be marked and zones that must not be marked. The laser marks the dark (black) areas, avoiding the bright (white) areas of the monochrome image. Color bitmaps can be converted to monochrome using an intensity threshold. The pixels of the original image whose intensity is below the threshold value are forced to dark and those above the threshold are forced to light. The 802 software can have a contrast effect control of 1007, to allow the user 20 to adjust the intensity / color conversion threshold. Each time the user presses said contrast control 1007, the 802 software will reprocess and re-display the entire image to the user. Increasing the contrast raises the threshold value, so that the original image is darker. The decrease in contrast reduces this threshold value, so that the original image is brighter.

 If the conversion of a color bitmap does not produce a satisfactory monochrome image, one of 30 graphic applications 806 mentioned

previously it can be used to edit the image. The manipulation of the color of the original image, possibly reversing the color map, can be useful for obtaining an image with a quality laser print and the desired visual appearance.

 Once the user reaches an acceptable threshold value and obtains a satisfactory monochrome image, he will be prepared to select the image parameters. In step 910, the user 10 clicks on an Image button 1003, and the 802 software displays a dialog box of the Image 1000 Parameters (Figure 10B). By means of said Image 1000 Parameters dialog box, the user can select several 15 parameters. The parameters may be expressed in units of points, except the residence time 1014, which is expressed in temporary units (for example, microseconds).

 Next, the pixels, the 20 dots and the spots are described. The original image (for example, image 600, which may be a bitmap), has a plurality of small bright and dark pixels. An original pixel image is converted to a new dot image, as described below. Digital-analog converters can be configured in the laser electronics to address points, which correspond to the possible positions in the product material at which the laser must stop to form visible spots. For example, the

Digital-analog converters of the electronics 26 of the laser 12 can address an area of the product that should be marked as a two-dimensional space of 4096x4096 addressable points, so that the point (2048, 2048) is near the center of the laser aperture 5. It is possible that the laser does not reach some of the 4096x4096 points, since its physical opening is circular, and for this reason the corners may not be marked. The points in the corner of the screen may be cut following a circular opening 10.

 Based on the points addressed by the digital-analog converters, the laser is capable of forming visible spots on the product material. The size of the different spots that the laser truly marks on the product depends on the material to be marked, the optics, the laser wavelength, the laser power and the residence time. In most cases, a real marked spot is several times larger than a single addressable point 20, as shown in Figure 16. For example, a real marked spot may have a diameter of sixteen addressable points. But each of the spots must be very small, for example 0.008 inches. 25

 The 802 software can provide default parameter values in the Image Parameters dialog box 1000. When the user presses the OK button 1022, in step 915 the 802 software checks a value specified by the user of the factor of pre-erosion, and eliminates

bordering pixels in step 920 a certain number of times specified by the user. After pre-erosion, in step 925 the 802 software traces the dark areas in the image selected by the user. For example, if the image constitutes the 5 letter "A" with fill of Figure 6, the 802 software generates a first continuous silhouette 702A of the letter "A". An additional example of a set of silhouettes 1080 is shown in Figure 10D, comprising a first silhouette 1081 and a second silhouette 1082.

 If there are multiple dark areas in the image, the 802 software generates a list of silhouettes for the dark areas in the image. Each of the silhouettes comprises several line segments that connect 15 multiple addressable points. The points are grouped into line segments in the same order as the laser offset between points. Points are stored as data in memory. The laser can be stopped at each point addressed N so as to form a pattern, the value of N being set from the value of the Step Between Points 1010. The Step Between Points parameter 1010 sets the distance between points in the same silhouette in the that the laser will stop to form spots. The Step 25 parameter between Points 1010 is measured along the direction of each line. If the Step Between Points 1010 is set to the value "1", then the laser will stop at each point of the silhouette, although this may prove ineffective, since the diameter of a real spot 30 formed by laser can comprise several points.

The smaller the value of the 1010 Step between Points, the closer the points will be, the longer it takes to mark, the greater a mark will resemble a continuous line and the more laser power will be supplied to the material. If the value 5 of the Step between Points 1010 is larger, the points are more differentiated, less power is delivered to the material and the image is marked more quickly.

 Once all the dark areas are plotted, in step 930 the 802 software checks the value 10 specified by the user of contour progression, and in step 935 the 802 software removes all border pixels from the dark areas of the original image a certain number of times specified by the user. A boundary pixel is a dark pixel that has at least one adjacent luminous pixel. For this reason, the size of the dark areas of the original image to be marked is reduced.

 In step 940, the 802 software checks if any dark area of the image remains, or if there are silhouettes that need to be drawn if the only silhouette mode described below is selected. If this is the case, the 802 software traces the remaining dark areas again, which creates another silhouette within the first silhouette or an additional set of silhouettes within the first set of silhouettes. For example, the second silhouette 702B of the letter "A" in Figure 7 is located within the first silhouette 702A. As an additional example, the second silhouette 1082 of the

Figure 10D is located within the first silhouette 1081. The 802 software repeats the plotting and eroding sequence until all dark areas of the image disappear. Thus, in step 945 the software 802 creates and displays a set 5 of continuous, concentric silhouettes 702A-702C (figure 7) that virtually approximates the original image 600 (figure 6).

 The Points between Silhouettes parameter 1002 (the contour progression factor) allows the user to control the number of boundary points that are removed between silhouettes, for example controlling the spacing between concentric silhouettes. The smaller the value of the Points between Silhouettes 1002, the more together the silhouettes will be marked, the more power will be delivered to the target and the more slowly the image will be marked. The larger the Points value between Silhouettes 1002, the more separated the marked silhouettes will be, the less power will be delivered to the target and the image will be marked more quickly. The Points between Silhouettes parameter 1002 effectively determines the total number of dotted line segments that will be used to mark dark areas of the image. The total number of dotted line segments in turn affects the time required to mark the image. By conveniently selecting (a) the spacing between marks along each silhouette and (b) the number of borderline pixels removed between the creation of silhouettes, an effective and accurate marking of a graphic image can be achieved.

 The 802 software can cause the laser to mark around the limit of the dark areas of the image, for example at ½ point. On the other hand, the laser spot size extends the marked area. Consequently, high resolution images, for example Chinese text, can be distorted. The original dark areas may appear together and the width of the mark made by the laser can join some dark areas.

 To solve this, the previous erosion parameter 10 1004 (figure 10B) establishes a number of borderline pixels removed before marking the first silhouette. The borderline pixels removed compensate for marking outside the dark areas by contracting these dark areas before making the first mark. The previous erosion parameter 1004 increases the size of the light zones in an image. The thickness of the original lines of the image must be greater than two pixels to survive after erosion. Erosion of an image with thin dark areas 20 can completely erase dark areas if the value of previous erosion 1004 is too large. The value 0 is a valid value for previous erosion 1004. Alternatively, the user could use graphic software, such as Microsoft 25 Paint, to separate the characters in the original image or change the color compression threshold to reduce the size of the dark areas

 The conversion of the pixel list of the original bitmap into dot silhouettes implies a compromise between the precision and the number of

line segments If a very high precision is selected, a line segment could be created for each original dark pixel. In one configuration, 802 software could generate about 8,000 line segments per image. 5

 Tolerance 1012 (or permissible error) determines the extent to which a line segment can diverge from reality before creating a new line segment. A small value of Tolerance 1012 forces many short line segments to follow curves. A large value of Tolerance 1012 represents reduced accuracy, which results in few line segments created and may distort the image being marked. Very large Tolerance 1012 values can create limits that are not concentric. Large Tolerance 1012 values tend to make the curves of the image straight. Right angles tend to tilt and text can be distorted for very low accuracy.

 Although the laser 12 does not use ink, the filling 20 of the large dark areas may require some time. With the parameter Only Silhouette 1006, the marking can be restricted to the outer limits. If the Only Silhouette 1006 option is checked, the Silhouettes box 1008 allows the user 25 to specify the number of silhouettes to be marked. If a single silhouette is not visible, the marking of additional little spaced silhouettes increases the visual impact. In Silhouette Only mode, the Points between Silhouettes parameter 1002 controls the spacing between silhouettes as long as

Silhouettes 1008 is set to a value greater than 1. If Silhouettes 1008 is set to 1, the Points between Silhouettes parameter 1002 does not affect the image.

 The Permanence Time 1014 for each spot is used to calculate the total time (in 5 microseconds) needed to mark the image, as shown in Figure 10C. The Dwell Time 1014 does not affect the image conversion process performed by the 802 software. The Dwell Time 1014 is included in order to provide a guideline for calculating the total estimated time while creating images. The actual residence time can be set in the user interface 30 of Figure 1A. Alternatively, there may be no dwell time setting, as in 15 vector laser printing systems.

 The display area of the PC screen can limit the maximum size of the original image that the 802 software can process to a value of 1024 x 1024 pixels. The Output Scaling parameter 1016 20 allows the user to create images larger than 1024 x 1024 pixels. The 802 software, running on a suitable PC, can read images larger than those of a width greater than 1024 pixels. For a laser with a 2 ”aperture, the marks of an image with a width of 25 1024 pixels have a width of 0.5”. A 2x Output Scaling implies a 1.0 ”width mark in a 1024 pixel image. A 4x Exit Scale would fill the opening and mark 2.0 ”. Output Scaling is not designed to control the exact size of the marked image. Is

The user needs to adjust the image size with an 806 graphic application to edit graphically by setting the resolution of the original bitmap. If the initial image turns out to be too large for the graphic application 806 5 to process, the Output Scaling 1016 provides a way to continue increasing the size of the marked image.

 The parameter box of the Image 1000 also offers the possibility of selecting the type of laser 1024 to be used, the desired focal length 1026, the units 1028 and the aperture size 1030. The rules 1009 and the aperture can be show in millimeters, centimeters or inches.

 By means of the Deviation parameter in the Opening 1018, 1020, the user can move the resulting mark away from the center of the opening. 802 software can provide limited formats that mix text and graphics. The user can combine Text Segments with different Deviation values in the Aperture to center the resulting mark in the opening. A positive value of X 1018 shifts the image to the right, while a positive value of Y 1020 shifts the image down. The Deviation values in Opening 1018 are signed, so that a negative X moves to the left and a negative Y up.

 If the user presses the OK button 1022, the 802 software instructs the computer to display a black image 1070. Each point to be marked is illuminated, as shown in Figure 10C. A

Results box 1071 reports the image marking time and the number of segments required. Image 1070 shows how the resulting points will be distributed in threshold image 1001 (Figure 10A). 5

 The user can then evaluate the image, and if he does not find it satisfactory, press the Image Redo button 1005. The parameter dialog box of Image 1000 appears again and the user is allowed to reset any parameter. The resulting image 10 is processed with the new parameters and displayed with a result box for the new settings.

 To adjust the threshold, the user can press the Image button 1003 and the screen 15 momentarily shows the original bitmap 1001. By controlling the contrast effect 1007, the user can adjust the threshold. When the desired threshold value is obtained, the Image button 1003 can be pressed again; the 20 parameter dialog box of Image 1000 appears so that the user can adjust any parameter.

 When the user obtains a satisfactory result, press the Save As 1072 button and a dialog box appears to save the file, 25 so that the user is allowed to navigate to the folder in which he wishes to save the processed image and enter a name for The image file. Once the file has been saved, the 802 software can be closed. On the other hand, the 30 Cancel 1073 button is available.

 The user can use an additional application, such as the Expert ™ 804 application described above, to download the resulting * .grf file. The 810 laser printing system can be used to mark the image and evaluate the result. 5 Line segments can be adjusted to obtain the desired image.

 An example technique is illustrated in Figure 11 that the 802 software can use to form a silhouette (Figures 7 and 10D) around a dark area 10 in an original bitmap image (Figures 6 and 10A). In step 1100, the 802 software finds original dark pixels at the outer edges / margin of a dark area in the original bitmap, at step 1102 it uses three points of greater resolution to address each of the original margin pixels , in step 1104 it determines how to connect said high resolution points in line segments to form a continuous silhouette around each dark area of the original image, and then in step 1106 it establishes the precision of the laser when following the dotted lines. when marking a contour line in the image. Then, in step 1108, the 802 software stores a set of points 25 selected for the silhouette.

 An example of two dark pixels of the margin 1200, 1202 (shaded area) of the original bitmap (figures 6 and 10A) addressed by smaller points of the 802 software is illustrated in Fig. 12. Such 802 software addresses the first

1200 dark pixel of the original bitmap with three points of higher resolution (x, y, 0), (x, y, 1), (x, y, 2) that are represented as circles in Figure 12. The three points Higher resolution can be attached to additional new points to form a contour line in a new converted image that has twice the resolution of the original bitmap image. The 802 software addresses the second dark pixel 1202 of the original bitmap with three smaller dots (x, y + 1, 0), (x, y + 1, 1), 10 (x, y + 1, 2). Additional small dots (circles) in Figure 12 can address any pixel in the original bitmap.

 Next, in step 1104, the 802 software determines how to connect the higher resolution dots in line segments to form a continuous silhouette around a dark area of the original image. For example, a line segment can be formed with new points (x + 1, y, 0), (x, y, 1), (x, y, 0), (x, y, 2), (x, y + 1, 0) and 20 (x, y + 1, 2). Each of the new points can be associated with an 8 or 16 bit array.

 In Figure 13A, 16 possible line segments associated with the original pixel are illustrated, as labeled, plus an additional two-line segment associated with an adjacent pixel. A 13-bit matrix 1300 is illustrated in Figure 13B which may designate the 16 line segments of Figure 13A. The 16-bit matrix can be associated with a new point in Figure 12 or with more points. 30

 The line segments and possible directions for three new points (x, y, 0), (x, y, 1), (x, y, 2) representing an original pixel are illustrated in Figure 14A. Sixteen line segments and their corresponding 5 addresses are illustrated in Figure 14B. A single new point and eight possible directions are illustrated in Figure 14C.

 In figures 15A to 15D 256 possible combinations (labeled 0 to 255) of 10 line segment formation for 256 possible combinations of nine pixels of the original image are illustrated. Dark pixels are indicated as dots. In any set of nine pixels there is a dark central pixel and zero or more additional dark pixels. For example, the upper left block of Figure 14A represents a single dark pixel with four line segments forming a silhouette around the dark pixel. Typically, the width or thickness of a dark area of an image 20 groups multiple pixels, not just one.

 Once a continuous silhouette is formed around the entire dark area of the original image, in step 1106, the 802 software determines how accurately the print beam must follow the 25 line segments when marking an image. This is determined by the Tolerance parameter 1012, described above with reference to Figure 10B.

 Figure 16 shows a series of 30 line segments 1600 that are part of a

silhouette. Line segments join points. The Step Between 1010 parameter, shown in Figure 10B, sets the points at which the laser beam will actually stop. As depicted, in Figure 16 the value of the Step between 5 Points 1010 is set to 8.

 An example of a technique to form a silhouette and generate positions that define the marking with the help of the laser is illustrated in Figure 17. In step 1700 an image is received. If necessary, the image can be converted to monochrome, so that every pixel has one of the two states corresponding to marked or clear. In step 1710, a connection matrix can be created, possibly involving the initialization of an empty connection matrix 15 of size (2x + 1) by (2y + 1) entries, having the original image x by and pixels. Any connection matrix input can contain any of the eight connections illustrated in Figure 14C, in which the connection indication by itself does not imply direction.

 To fill the connection matrix, for each pixel that must be marked in the image it is necessary to locate the correspondence pattern of the connection diagrams of Figures 15A to 15D and copy all the connections of said pattern into the connection matrix. In the connection diagrams depicted in Figures 15A to 15D, the pixel corresponds to the central pixel in each individual diagram, as it should be marked. The status of the 30 eight neighboring pixels of said pixel determines that

select pattern. The neighboring pixels beyond the margin of the monochrome image can be considered to be in a marked state. Once the connection matrix is full, every point of the connection matrix has either zero or two connections due to the connection patterns specified in Figures 15A to 15D.

 Next, in step 1720 one or more silhouettes are created and added to a set of silhouettes belonging to the image. This can be done using a procedure defined in the following pseudocode:

Go through the connection matrix and as long as unprocessed points remain {

 If a point with connections is found {

  record that point as a starting point of a silhouette; fifteen

  Run {

         follow a connection to the next point; [for the starting point, choose one to follow]

         records the current point as the next point of the silhouette;

         delete this connection, both from the point just to the left and the current point;

  } Until (the current point is the starting point) 20

 } [for each point, reaching the point one of its connections is deleted and leaving the point the other connection is deleted]

}

 Therefore, a set of silhouettes is created, each of which constitutes an ordered set of points. The orderly connection of these points creates a silhouette around a contiguous group of pixels that must be marked in the original image at twice the resolution.

 The pixels in the margin can be removed N 30 times in step 1730. N can be one, or a larger value number selected by the user. For example, you can create an empty list of pixels

whose status should be set to unmarked. For each pixel that must be marked in the image, if said pixel has a neighbor that should not be marked, said pixel can be added to the list. The status of all the pixels in the list created in this way can then be set to unmarked, and this procedure can be repeated the number of times set by the user. In this way, the pixels in the margin of each contiguous pixel zone that should be marked are eliminated, reducing the area that should be marked. If in step 1740 in the reduced area there are pixels to be marked, additional silhouettes can be created by repeating the operations described above, and therefore adding them to the set of silhouettes already created. fifteen

 Once all the pixels that have to be marked have been plotted, the resulting set of essentially concentric silhouettes that fill the area to be marked with the original image has twice the resolution of the original image and can be used to focus a system Laser printing In step 1750, the silhouettes can be sorted according to a moving product and the time at which each part of the silhouettes is expected to enter the laser printing opening. 25 This can be done to optimize the marking of a moving product. One procedure is to start with the silhouette that contains the points that enter the opening sooner during marking and then order said silhouette 30 to begin with the point that enters earlier.

This procedure is repeated for the remaining additional silhouettes.

 Then, in step 1760, the silhouettes can be transformed into approximate silhouettes. For example, this can be done using a procedure defined in the following pseudocode:

For each silhouette {

 the starting point PB takes the first point of the silhouette;

 the end point PE takes the second point of the silhouette; 10

 While {additional points remain in the silhouette after PE} {

  set the overpassed_tolerance_indicator to FALSE;

  Run {

   Calculate a line segment between PB and PE;

   For each point of the silhouette between PB and PE 15

    Yes (your distance to the current line segment exceeds a set tolerance_value)

     set the overpassed_tolerance_indicator to TRUE;

   Yes (the overpassed_tolerance_indicator is FALSE)

    If (a point exists in the silhouette after PE) gives PE the value 20 of PE + 1;

    Otherwise set the overrun_tolerance_indicator to TRUE

  } Until (the overpassed_tolerance_indicator is TRUE)

  Yes (a point exists in the silhouette after PE) {

   provides the second to the last line segment; [which is from PB to PE-1} 25

   gives PB a value equal to that of PE-1;

  } otherwise it provides the last line segment;

 }

} 30

Therefore, any silhouette can be transformed into a set of lines that approximates it.

 In step 1770, said lines can be converted into points defining the marking with the help of a laser. Such conversion can be based on each particular laser printing system used. For example, for laser printing of staggering and repetition with variable residence time, described above, said lines can be transformed directly into a set of position and marking commands, based on the distance of travel between marks specified by the user.

Thus, for each silhouette: (1) you can generate a scroll command until the beginning of the first line; (2) if the distance at the end of the line is less than the distance specified by user, the line is complete; and (3) the distance at the end of the line is greater than the distance specified by the user, a dialing command can be created for that line, and the marking is repeated.

 Although the present application has been described in detail, it should be understood that different changes, combinations, substitutions or alterations can be made. For example, additional modes for converting an original bitmap image (figures 6 and 10A) into a set of silhouettes (figures 7 and 10D) can be implemented.

DOCUMENTS CITED IN THE DESCRIPTIVE MEMORY

The following list of the documents mentioned by the applicant has been made exclusively for the purpose of informing the reader and is not part of the European patent document. It has been prepared with great care; however, the European Patent Office assumes no responsibility in the event of errors or omissions.

 10

Documents cited in the specification

 US 6791592 B [0083]

 US 89006904 A [0083]

 US 69335603 A [0083] 15

 US 74193003 A [0083]

Claims (16)

1. Method of filling an area of an image by marking on a material with the aid of a laser beam, comprising:

the conversion of the area of the image to be marked on the material with the help of a laser beam in a set of positions: progressively defining smaller contours of the image area, and 10 converting each defined contour into a set of separate positions that can be used to direct the laser beam; Y marking the material with the help of the laser beam 15, guiding it conveniently so that it stops in the different positions and so that it moves between them.

2. The method according to claim 1, wherein the conversion of the image into a set of 20 positions implies:

identify a set of dots that border the boundary pixels of a marking zone of the image, so that with said set of dots a contour of the marking zone is formed; eliminate the border pixels with respect to the definition of the contours for the marking zone; 30 re-carry out identification and deletion until all the pixels of interest in the marking area have been considered; as well as determine the positions from the identified points. 5

3. The method according to claim 2, wherein the identification of the set of points implies identifying points extracted from an image space having a higher density than that of the image. 10

4. The method according to claim 3, wherein the identification of the set of points also implies identifying the points based on a certain programmable tolerance value. fifteen

5. The method according to claim 2, wherein the removal of the border pixels involves removing pixels based on a programmable contour progression factor.

6. The method according to claim 2, wherein the pixels of interest can be defined by a programmable silhouette-only configuration.

7. A method according to claim 2, wherein determining the positions from the identified points implies determining the positions from the identified points based on a programmable step size.

A method according to claim 2, wherein the image comprises a generated image, and also comprising generating said image generated from a source image based on a programmable intensity threshold. 5

9. The method according to claim 2, which also initially involves removing borderline pixels from the marking zone based on a programmable pre-erosion value.

10. Method according to claim 2, wherein the marking of the material with the aid of the laser beam involves continuously guiding the laser beam according to the positions, in an order that corresponds to the progressively smaller contours, using a laser printer of 15 staging and repetition and presenting a period of variable permanence.

11. The method according to claim 1, wherein the marking of the material with the aid of the laser beam implies directing said beam towards a product and its moving material according to the positions, in an order that corresponds to the progressively smaller contours and that it corresponds to the times at which the progressively smaller contours 25 enter the laser printing aperture.

12. The method according to claim 11, wherein the progressively smaller contours comprise overlapping contours.

13. System (10) for filling an area of an image by marking on a material with the aid of a laser beam (14), comprising;

a laser (12) that can be operated to produce the laser beam (14); 5 an optical assembly (18) that can be used to focus and direct the laser beam; and one or more machines (26) that can be used to convert the area of the image to be marked on the material (20) with the aid of a laser beam in a set of positions progressively defining small contours of the image area and converting each defined contour into a set of separate positions that can be used to direct the laser beam, and mark the material with the aid of the laser beam by controlling the laser and the optical assembly to direct the laser beam, so that it stops at the different positions and to move between them.

14. System according to claim 13, wherein the conversion of the image into a set of positions involves performing the following operations:

identify a set of dots that border the boundary pixels of a marking area of the image, so that with said set of dots a contour of the marking zone is formed; 30 eliminate the border pixels with respect to the definition of the contours for the marking zone; re-carry out the identification and elimination until all the pixels of interest in the marking area have been considered 5; as well as determine the positions from the identified points.

15. Computer program that can be used in order for one or more machines to carry out operations 10 including the filling of an area of an image by marking on a material with the aid of a laser beam, comprising:

the conversion of the area of the image to be marked on the material with the aid of a laser beam in a set of positions progressively defining smaller contours of the area of the image and converting each defined contour into a set of separate positions that can be used to direct the laser beam; Y the marking of the material with the help of the laser beam, guiding it conveniently so that it stops in the different positions and so that it moves between them. 25

16. Computer program according to claim 15, wherein the image conversion comprises:

identify a set of dots that border the boundary pixels of a marking area of the image, so that with said set 30 from points a contour of the marking zone is formed; eliminate the border pixels with respect to the definition of the contours for the marking zone; 5 re-carry out identification and deletion until all the pixels of interest in the marking area have been considered; as well as determine the positions from the identified points. 10