Laser marking apparatus, marking method, and printing setting apparatus

Abstract

To provide a laser marking device, a marking method and a print setting apparatus which more easily performs thick line printing having a satisfactory line width than heretofore.SOLUTION: A laser marking device L includes a laser beam outputting part 3 which outputs a laser beam, a laser beam scanning part 4 which scans a laser beam on the surface of a workpiece W, a storage part 102 which stores printing data Df for thick line having a plurality of scanning lines arranged in such a direction that line elements of a letter thicken and a marking control part 104 which controls the laser beam outputting part 3 and the laser beam scanning part 4 so as to perform marking of letters. The marking control part 104 scans a UV laser beam along an outer side scanning line separated from an inner side center line Mc prior to the inner side scanning line which approaches the center line Mc of the line element of the letter corresponding to the printing data Df for the thick line with respect to a scanning line adjacent to each other in such a direction that the line element of the letter thickens, of a plurality of scanning lines constituting printing data Df for thick lines.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The technologies disclosed herein relate to a laser marking apparatus, a marking method, and a printing setting apparatus. [Background technology]

[0002] Patent Document 1 discloses an example of a laser marking apparatus. Specifically, the laser marking apparatus disclosed in Patent Document 1 can perform wobble processing on a workpiece by scanning a laser beam in a helical manner across the surface of the workpiece.

[0003] By using a wobble process like the one described in Patent Document 1, it is possible to print characters with thicker lines, so-called thick-line printing, on the surface of a workpiece. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2014-046330 [Overview of the project] [Problems that the invention aims to solve]

[0005] When using a wobble process as disclosed in Patent Document 1, the printing cycle time may become longer. Therefore, instead of using a wobble process, it is conceivable to achieve thick line printing by setting multiple scan lines along the center line of the character to be printed.

[0006] When printing thick lines using multiple scan lines, conventional methods have been considered to print the scan line that roughly coincides with the center line of the character first, then print the other scan lines adjacent to it in an order that widens the line width of the center line, or to print each scan line in order from the scan line closest to the inner contour of the character in order to suppress the accumulation of thermal energy inside the closed curve when some of the multiple scan lines form a closed curve.

[0007] If the former order is adopted, the scan line furthest from the center line of a character will be printed after the scan lines closest to that center line. If the latter order is adopted, the scan line furthest from the inner contour of a character will be printed after the other scan lines. The scan line furthest from the center line or inner contour of a character corresponds to the scan line that will be printed almost last, and in both cases, it will form the outer contour of the character, which will be made thicker.

[0008] Here, we consider a case where UV laser light is used as the laser beam, and thick line printing using multiple scanning lines is performed on a workpiece that undergoes a chemical reaction with the UV laser light, as described above.

[0009] In this case, when UV laser light is shone along one of multiple scan lines, fume is generated from the shone area, creating a small gap. Subsequently, when UV laser light is shone along another scan line adjacent to that scan line, similar fume is generated in that area, and this fume flows into the aforementioned small gap. As a result, scan lines printed later (other scan lines adjacent to the first scan line) may not be printed sufficiently. This is because the fume adhering to the walls of the gaps affects the color development of the print. In this case, the amount of fume that adheres affects the density of the print.

[0010] Therefore, if each scan line is printed in the order described above, the scan line printed almost last may not be printed sufficiently due to the inflow of fumes. Considering that this scan line forms the outer contour of the character, it is difficult to achieve thick line printing with sufficient line width using the order that has been considered in the past.

[0011] The technology disclosed herein has been developed in view of the above, and its purpose is to make it easier than before to print thick lines with sufficient line width in laser marking of characters. [Means for solving the problem]

[0012] A first aspect of this disclosure relates to a laser marking apparatus comprising: a laser light output unit that generates and outputs laser light based on excitation light; a laser light scanning unit that scans the laser light output from the laser light output unit on the surface of a workpiece; a storage unit that stores thick line printing data having scan lines along the line elements of characters to be marked, wherein the scan lines are arranged in a direction that makes the line elements thicker; and a marking control unit that controls the laser light output unit and the laser light scanning unit to mark characters by scanning the laser light along the scan lines of the printing data based on the printing data stored in the storage unit.

[0013] Furthermore, according to a first aspect of the present disclosure, the marking control unit controls the laser beam scanning unit such that, with respect to the scan lines adjacent to each other in the direction in which the line element thickens, the laser beam is scanned along the outer scan line which is further away from the center line compared to the inner scan line, before the inner scan line which is closer to the center line of the line element of the character corresponding to the thick line printing data.

[0014] In this context, "scan lines" refer to the trajectory of the laser beam on the surface of the workpiece. These scan lines are set to extend along the line elements that make up a character. By increasing the number of scan lines extending along a line element, that line element can be made thicker. By making multiple line elements thicker, the character composed of those line elements can be made bold.

[0015] According to a first aspect of this disclosure, the marking control unit determines the scanning order of each scan line with respect to the center line of the character's line element. Specifically, for two adjacent scan lines, the scan line further from the center line is scanned first. As a result, the scan lines forming the outer contour are scanned in an earlier order than before, enabling higher quality printing. Consequently, thick line printing with sufficient line width becomes easier to achieve than before.

[0016] Furthermore, according to a second aspect of this disclosure, the laser marking apparatus may include a display means for displaying a setting plane defined by a Cartesian coordinate system, a character input means for receiving input of characters to be marked, which is placed on the setting plane displayed by the display means, and a printing data generation unit for generating thick line printing data having a plurality of scan lines arranged in the direction in which the line elements of the characters received by the character input means become thicker, wherein the storage unit stores the thick line printing data generated by the printing data generation unit.

[0017] According to the second embodiment, the laser marking apparatus is equipped with various user interfaces for generating thick line printing data. This makes it possible to easily achieve thick line printing while maintaining usability.

[0018] Furthermore, according to a third aspect of this disclosure, the direction in which the line element thickens may be a direction perpendicular to the center line of the line element.

[0019] According to the third embodiment described above, each line element constituting a character can be appropriately thickened.

[0020] Also, according to a fourth aspect of the present disclosure, the laser light output unit includes a solid laser crystal that generates fundamental wave laser light based on excitation light, and a non-linear optical crystal that generates UV laser light based on the fundamental wave laser light generated by the solid laser crystal, and the laser light may be output as the UV laser light generated by the non-linear optical crystal.

[0021] According to the fourth aspect, thick-line printing can be easily realized without causing the problems related to the fume described above.

[0022] Also, according to a fifth aspect of the present disclosure, among the plurality of scanning lines constituting the thick-line printing data, scanning lines forming the outline of the character are included, and the marking control unit may control the laser light scanning unit to scan the UV laser light in order from the scanning lines forming the outer outline of the character among the plurality of scanning lines constituting the thick-line printing data.

[0023] According to the fifth aspect, the control unit preferentially scans the scanning lines forming the outer outline of the character. Thereby, the outline of the character can be printed with high quality, and thus it is advantageous for more easily realizing thick-line printing with a sufficient line width than in the past.

[0024] Also, according to a sixth aspect of the present disclosure, the workpiece may be composed of a sheet-like multilayer film, and the multilayer film contains at least a surface layer, a UV reaction layer that chemically reacts with the UV laser light, and a sealant layer that sandwiches the UV reaction layer between the surface layer.

[0025] According to the sixth aspect of the present disclosure, the laser marking device can be configured to be suitable for printing on a film containing a UV reaction layer.

[0026] Also, according to a seventh aspect of the present disclosure, among the plurality of scanning lines constituting the thick-line printing data, scanning lines extending along the center line of the character may be included.

[0027] According to the seventh embodiment, the plurality of scan lines may include scan lines that extend along the center line of a character.

[0028] Furthermore, according to an eighth aspect of this disclosure, the marking control unit may control the laser beam scanning unit such that, in each of the plurality of scanning lines constituting the thick line printing data, the portion constituting the end of the character is divided.

[0029] According to the eighth embodiment, the marking control unit divides the scan lines in the portion corresponding to the edge of the character and excludes it from the UV laser irradiation target. Generally, the edges of characters are prone to degradation, so excluding such portions from the UV laser irradiation target is advantageous in improving the quality of thick line printing.

[0030] Furthermore, according to a ninth aspect of this disclosure, the plurality of scanning lines constituting the thick line printing data include a closed curve, and the marking control unit controls the laser beam scanning unit to provide a gap between the start and end points of the closed curve when UV laser light is scanned along the closed curve.

[0031] According to the ninth embodiment described above, when a closed curve is included in a plurality of scan lines, the marking control unit does not directly connect the start and end points of the closed curve, but instead provides a gap between them. This suppresses the occurrence of delamination and is advantageous in improving the quality of thick line printing.

[0032] Furthermore, according to a tenth aspect of this disclosure, the laser light output unit may adjust the laser power of the UV laser light within a range of 0.8 W to 1.6 W.

[0033] An eleventh aspect of this disclosure relates to a laser marking apparatus comprising: a laser light output unit that generates and outputs laser light based on excitation light; a laser light scanning unit that scans the laser light output from the laser light output unit on the surface of a workpiece; a storage unit that stores thick line printing data having scan lines along the line elements of characters to be marked, wherein the scan lines are arranged in a direction that makes the line elements thicker; and a marking control unit that controls the laser light output unit and the laser light scanning unit to mark characters by scanning the laser light along the scan lines of the printing data based on the printing data stored in the storage unit.

[0034] Furthermore, according to an eleventh aspect of the present disclosure, the marking control unit controls the laser beam scanning unit to scan the UV laser beam in an order that prioritizes the scan lines forming the outline of the characters among the plurality of scan lines constituting the thick line printing data over the other scan lines.

[0035] Here, the term "character outline" is used in a broad sense. For example, in the case of the number "0," the character outline includes both the inner outline that follows the inner circumference of the "0" and the outer outline that follows the outer circumference of the "0." On the other hand, in the case of the number "1," the character outline includes only the "outer outline."

[0036] Furthermore, the term "priority order" as used herein means the order in which the scanning sequence of multiple scan lines is divided into an earlier first half and a later second half, and the scan lines belong to the first half. According to the eighth aspect of this disclosure, the scan lines forming the outline of a character are scanned in the order that belongs to the first half.

[0037] According to an eleventh aspect of this disclosure, the marking control unit determines the scanning order of each scan line based on the contour of the character. Specifically, the scan lines that form the contour of the character are scanned with priority over other scan lines. As a result, the scan lines that form the outer contour are scanned earlier than in the conventional method, enabling higher quality printing. Consequently, thick line printing with sufficient line width becomes easier to achieve than in the conventional method.

[0038] Furthermore, according to a twelfth aspect of the present disclosure, the marking control unit may, when a portion of the plurality of scan lines constituting the thick line printing data intersects, process the second and subsequent intersection points as invalid portions, and control the laser beam output unit so that when the laser beam is scanned over the invalid portions by the laser beam scanning unit, a smaller amount of laser beam is output compared to the non-invalid portions.

[0039] Furthermore, according to a thirteenth aspect of this disclosure, the laser marking apparatus may include means for acquiring movement information of a moving workpiece, and the marking control unit may control the laser beam scanning unit based on the movement speed and direction of movement specified by the workpiece movement information, so that the plurality of scanning lines constituting the thick line printing data follow the movement of the workpiece.

[0040] Furthermore, a 14th aspect of this disclosure relates to a marking method for marking characters on the surface of a workpiece using a laser marking apparatus comprising: a laser light output unit that generates and outputs laser light based on excitation light; a laser light scanning unit that scans the laser light output from the laser light output unit on the surface of a workpiece; a storage unit that stores thick line printing data having scan lines along the line elements of characters to be marked, wherein the scan lines are arranged in a direction that makes the line elements of the characters thicker; and a marking control unit that controls the laser light output unit and the laser light scanning unit to scan the laser light along the scan lines of the printing data based on the printing data stored in the storage unit to mark the characters.

[0041] Furthermore, according to a fourteenth aspect of the present disclosure, the marking method is performed such that the marking control unit controls the laser light output unit and the laser light scanning unit so that, with respect to the scanning lines of a plurality of scanning lines constituting the thick line printing data, the laser light is scanned along the outer scanning line which is further away from the center line compared to the inner scanning line, before the inner scanning line which is closer to the center line of the line element of the character corresponding to the thick line printing data, for scanning lines adjacent to each other in the direction in which the line element becomes thicker, in order to mark the character.

[0042] Furthermore, a 15th aspect of the present disclosure relates to a printing setting device connected to a laser marker which includes a laser light output unit that generates and outputs laser light based on excitation light, and a laser light scanning unit that scans the laser light output from the laser light output unit on the surface of a workpiece, and which generates printing data having scanning lines along the line elements of characters to be marked by the laser light scanning unit.

[0043] Furthermore, according to a 15th aspect of the present disclosure, the printing setting device comprises: display means for displaying a setting plane defined by a Cartesian coordinate system; character input means for receiving input of characters to be marked, which are arranged on the setting plane displayed by the display means; printing data generation unit for generating thick line printing data having a plurality of scan lines arranged in the direction in which the line elements of the characters input by the character input means become thicker; and printing data transmission unit for transmitting the thick line printing data generated by the printing data generation unit to the laser marker, wherein the printing data generation unit generates thick line printing data such that, with respect to adjacent scan lines in the direction in which the line elements become thicker, the outer scan lines which are further away from the center line compared to the inner scan lines which are closer to the center line of the line elements of the characters corresponding to the thick line printing data are scanned before the inner scan lines which are closer to the center line of the line elements of the characters corresponding to the thick line printing data. [Effects of the Invention]

[0044] As explained above, this disclosure makes it easier to print thick lines with sufficient line width in laser marking than in conventional methods. [Brief explanation of the drawing]

[0045] [Figure 1] Figure 1 is a diagram illustrating the overall configuration of a laser marking system. [Figure 2] Figure 2 is a block diagram illustrating the schematic configuration of a laser marking apparatus. [Figure 3] Figure 3 is a diagram illustrating the replacement of the printing device and the marker head. [Figure 4] Figure 4 is a diagram illustrating the printing data for thick lines. [Figure 5] Figure 5 illustrates the basic concept of the scanning order according to this embodiment. [Figure 6] Figure 6 shows a first comparative example of the scanning order. [Figure 7] Figure 7 shows the first embodiment of the scanning sequence. [Figure 8] Figure 8 shows a second comparative example of the scanning order. [Figure 9] Figure 9 shows a second embodiment of the scanning sequence. [Figure 10] Figure 10 shows a third embodiment of the scanning sequence. [Figure 11] Figure 11 is a flowchart illustrating the procedure for determining the scanning order. [Figure 12] Figure 12 illustrates a user interface related to the scanning order. [Figure 13] Figure 13 illustrates a user interface related to the scanning order. [Figure 14] Figure 14 is a flowchart showing another example of the procedure for determining the scanning order. [Modes for carrying out the invention]

[0046] The embodiments of this disclosure will be described below with reference to the drawings. Note that the following description is illustrative.

[0047] In other words, in this embodiment, printing (hereinafter referred to as "marking" or simply "processing") will be described as a typical example of marking using UV laser light, but this disclosure can be applied to any marking consisting of multiple scan lines, such as graphic marking.

[0048] <Overall Structure> Figure 1 illustrates the overall configuration of the laser marking system S, and Figure 2 illustrates the schematic configuration of the laser marking device L in the laser marking system S. Figure 3A is a diagram illustrating the replacement of the printing device 1001 with the marker head 1.

[0049] The laser marking system S illustrated in Figure 1 comprises a laser marking device L, external equipment 400 connected thereto, and processing equipment 500 to which the laser marking device L is attached and which transports the workpiece W. Of these, the laser marking device L illustrated in Figures 1 and 2 is configured to irradiate a laser beam toward a predetermined irradiation area R1 to perform marking on the workpiece W corresponding to a predetermined printing pattern Pp.

[0050] The irradiation area R1 referred to here is a region set on the surface of the workpiece W, and corresponds to the printing surface pre-associated with the setting plane R2 described later. The irradiation area R1 as the printing surface can take various forms depending on the relative positional relationship between the laser marking device L and the workpiece W, the specifications of the laser marking device L, the movement path of the workpiece W, etc. For example, the irradiation area R1 of a workpiece W moving along a two-dimensional plane will be a plane along its movement path. On the other hand, the irradiation area R1 of a workpiece W moving in three-dimensional space may be a curved surface along its movement path.

[0051] Furthermore, the printing pattern Pp in the following description includes not only the pattern of characters to be marked on workpiece W, but also the pattern of shapes to be marked on workpiece W, such as ":", "×", barcodes, and QR codes (registered trademarks).

[0052] In particular, the laser marking apparatus L according to this embodiment can emit laser light having a wavelength of around 350 nm as the laser light for processing the workpiece W. This wavelength is included in the ultraviolet wavelength range. Therefore, in the following description, the laser light for processing the workpiece W may be referred to as "UV laser light" to distinguish it from other laser light such as near-infrared light.

[0053] The following describes a case where a workpiece W, composed of a sheet-like film, is to be marked, and the film contains a UV reaction layer X that chemically reacts with UV laser light.

[0054] However, the workpiece W that can be used as a marking target in this disclosure is not limited to workpiece W composed of a sheet-like film. In addition to plastic films, workpiece W made of various materials such as films containing an aluminum layer, films containing an aluminum vapor deposition layer, and films containing a paper layer may be used as marking targets. Furthermore, workpiece W may have a three-layer structure consisting of a surface layer, a UV-reactive layer, and a sealant layer. In the three-layer structure, the UV-reactive layer is sandwiched between the surface layer and the sealant layer. The surface layer may be made of, for example, polybutylene terephthalate (PBT) or stretched PP (OPP). The UV-reactive layer may be a layer containing titanium dioxide, for example. The sealant layer may be made of, for example, a polyolefin film that can be heat-melt bonded. In addition, other layers may be added to create a four-layer or five-layer structure. In this case, workpiece W will be composed of a sheet-like multilayer film.

[0055] Furthermore, although the laser marking apparatus L according to this embodiment is configured to perform so-called two-dimensional printing by scanning the laser beam in two dimensions, this laser marking apparatus L is configured to have a deeper depth of field than conventional products, so it can also perform so-called three-dimensional printing. Therefore, this laser marking apparatus L can even mark workpieces W that are transported along a three-dimensional movement path.

[0056] As shown in Figures 1 and 2, the laser marking apparatus L according to this embodiment comprises a marker head 1, a marker controller 100, an electrical cable 200, and an operating terminal 300.

[0057] Of these, the marker controller 100 can accept settings related to the printing pattern Pp and is configured as a controller for controlling the marker head 1.

[0058] On the other hand, the marker head 1 can emit UV laser light toward the irradiation area R1 by being controlled by the marker controller 100.

[0059] In this embodiment, the marker head 1 and the marker controller 100 are separate components and connected by an electrical cable 200. This electrical cable 200 includes at least electrical wiring that transmits power from inside the marker controller 100 (specifically, from the power supply unit 105 described later) to the outside. Specifically, the electrical cable 200 according to this embodiment is composed of bundled electrical wiring for transmitting power and signal wiring for sending and receiving analog signals, digital signals, etc.

[0060] The marker head 1 according to this embodiment is installed on processing equipment 500 that processes a workpiece W made of a sheet-like film. As shown in Figure 3, the processing equipment 500 includes a support member 501 that supports the marker head 1 and a conveyor roller 502 on which the workpiece W is wrapped.

[0061] Of these, the support member 501 can be used to attach the housing 10 of the laser marking device L, particularly the marker head 1, to a predetermined mounting position, as shown in Figure 3. Figures 1 and 3 illustrate a support member 501 configured to suspend the housing 10 from above, but the housing 10 may also be supported from other directions, such as the side.

[0062] On the other hand, the conveying roller 502 is configured in a cylindrical shape with a central axis extending in the short direction of the workpiece W. In this case, the workpiece W is conveyed in the long direction along a predetermined movement path by the rotation of the conveying roller 502.

[0063] Here, as shown in the upper and lower figures of Figure 3, the processing equipment 500 according to this embodiment is shared between the marker head 1 according to this embodiment and the printing device 1001 that prints using a method other than laser marking.

[0064] In other words, the marker head 1 according to this embodiment is configured to be attached to the support member 501 of the processing equipment 500, which is configured to mount the printing device 1001, in place of the printing device 1001.

[0065] Examples of a printing device 1001 that can replace the marker head 1 include a thermal transfer industrial thermal printer (TTO), but it can also be replaced with other printing devices 1001.

[0066] The printing device 1001 that can be replaced by the marker head 1 may, for example, include a housing 1010 configured in a substantially rectangular parallelepiped shape, which has a printing surface 1010d that exposes a printing section 1006 that contacts the printing area on the workpiece W, and a connecting surface 1010u that is different from the printing surface 1010d and can be connected to the support member 501.

[0067] In this case, as shown in the upper and lower figures of Figure 3, the marker head 1 is supported by a support member 501 that can be connected to the connection surface 1010u, similar to the printing device 1001. The supported marker head 1 then irradiates UV laser light toward an irradiation area R1, which is set to correspond to the printing area (the area that comes into contact with the printing unit 1006 in the printing device 1001), thereby marking the workpiece W.

[0068] On the other hand, the operating terminal 300 has, for example, a central processing unit (CPU) and memory, and is connected to the marker controller 100 so as to be able to send and receive electrical signals via wired or wireless means.

[0069] In this embodiment, the operating terminal 300 is configured as a personal computer such as a desktop computer or laptop computer, but this disclosure is not limited to such configurations. For example, the operating terminal 300 may be configured as a dedicated terminal that can be connected to the laser marking device L, such as a touch panel console. Furthermore, the operating terminal 300 can be integrated into, for example, the marker controller 100.

[0070] The operation terminal 300 functions as a terminal for setting various printing conditions, such as character size, and for displaying information related to marking the workpiece W to the user. This operation terminal 300 includes a display unit 301 for displaying information to the user, an operation unit 302 for receiving user input, and a storage device 303 for storing various information. The operation terminal 300 may also be called a printing setting device for setting various printing conditions. The marker head 1 and marker controller 100 may also be collectively referred to as a laser marker.

[0071] The display unit 301 can display a setting plane R2 defined by orthogonal coordinates. This display unit 301 is an example of a "display means" in this embodiment. As shown in Figure 1, an input interface Iu that receives input of characters to be marked (hereinafter referred to as "printing pattern Pp") is arranged on the setting plane R2 displayed by the display unit 301. As will be described in detail later, this input interface Iu consists of a user interface such as a frame indicating the range of the setting plane R2 and a figure indicating the position of the printing pattern Pp on the setting plane R2. Based on operation input to the operation unit 302, it receives input of the printing pattern Pp and can display the content of the received printing pattern Pp on the setting plane R2. The input interface Iu is an example of a "character input means" in this embodiment.

[0072] Specifically, the display unit 301 can be made of a liquid crystal display or an organic EL panel. If the operating terminal 300 is incorporated into the marker controller 100 or a touch panel console is used, the display screen provided on the marker controller 100 or the console can be used as the display unit.

[0073] The operating unit 302 can be configured with a keyboard and a pointing device. Pointing devices include mice, joysticks, etc. When the operating terminal 300 is incorporated into the marker controller 100 or a touch panel console is used, switches, buttons, etc. provided on the marker controller 100 or console can be used as the operating unit.

[0074] As described above, the operating terminal 300 can set the printing conditions for marking based on user input. These printing conditions include details of the printing pattern Pp, as well as the target output of the laser beam (laser power) and the scanning speed of the laser beam on the workpiece W (scan speed).

[0075] The printing conditions set by the operating terminal 300 are output to the marker controller 100 and stored in the storage unit 102 of the marker controller 100. If necessary, the storage device 303 of the operating terminal 300 may also store the printing conditions.

[0076] External devices 400 are connected to the marker controller 100 as needed. In the example shown in Figures 1 and 2, the external devices 400 include a transport speed sensor 401 and a programmable logic controller (PLC) 402.

[0077] The transport speed sensor 401 is configured, for example, by a rotary encoder and can detect the transport speed of the workpiece W. The transport speed sensor 401 outputs a signal (detection signal) indicating the detection result to the marker controller 100. The marker controller 100 controls the two-dimensional scanning of the laser beam, etc., based on the detection signal input from the transport speed sensor 401.

[0078] The PLC402 is configured, for example, with a microprocessor and can input control signals to the marker controller 100. The PLC402 is used to control the laser marking system S according to a predetermined sequence.

[0079] In addition to the equipment and devices described above, the laser marking apparatus L can be connected wirelessly or via wired connections to devices for operation and control, computers for various other processes, storage devices, peripheral devices, etc.

[0080] <Markerhead 1> As shown in Figure 2, the marker head 1 comprises, as its main components, an excitation light generation unit 2, a laser light output unit 3, and a laser light scanning unit 4. The excitation light generation unit 2 generates excitation light to excite the UV laser light based on power supplied from the marker controller 100 via an electrical cable 200. The laser light output unit 3 generates UV laser light based on the excitation light generated by the excitation light generation unit 2 and outputs the UV laser light. The laser light scanning unit 4 scans the UV laser light output from the laser light output unit 3 on the surface of the workpiece W by deflecting the UV laser light.

[0081] The marker head 1 also includes a housing 10 that houses the aforementioned components, namely the excitation light generation unit 2, the laser light output unit 3, and the laser light scanning unit 4. The housing 10 has an emission window 6 through which UV laser light deflected by the laser light scanning unit 4 is transmitted. Although details are omitted, the housing 10 has a roughly rectangular parallelepiped shape and has an emission surface 10d on which the emission window 6 is formed, and a mounting surface 10u which is different from the emission surface 10d and can be connected to the support member 501. The mounting surface 10u is connected to the support member 501 via an attachment 7.

[0082] (Excitation light generation unit 2) The excitation light generation unit 2 is configured to receive power from the power supply unit 105 via the electrical cable 200 and to generate excitation light corresponding to that power. The excitation light generation unit 2 according to this embodiment has an excitation light source (not shown) composed of, for example, a laser diode (LD). It should be noted that housing the excitation light generation unit 2, particularly the excitation light source, within the housing 10 is not essential, and it may be housed within the marker controller 100.

[0083] (Laser light output unit 3) The laser light output unit 3 includes a solid laser crystal 31 that generates a fundamental wave (fundamental laser light) based on excitation light, and a nonlinear optical crystal 32 that generates UV laser light based on the fundamental wave (fundamental laser light) generated by the solid laser crystal 31. The laser light output unit 3 outputs the UV laser light generated by the nonlinear optical crystal 32 as the laser light for marking.

[0084] In this embodiment, a rod-shaped Nd:YVO4 (yttrium vanadite) is used as the laser medium constituting the solid laser crystal 31. Laser excitation light is incident from one end face of the rod-shaped solid laser crystal 31, and laser light having the fundamental wavelength (so-called fundamental wave) is emitted from the other end face (a so-called unidirectional excitation method by end pumping). In this embodiment, the fundamental wavelength is set to 1064 nm. On the other hand, the wavelength of the excitation light is set near the central wavelength of the absorption spectrum of Nd:YVO4 in order to promote stimulated emission. However, this is not limited to this example, and other laser mediums such as rare earth-doped YAG, YLF, GdVO4, etc. can also be used.

[0085] Furthermore, the nonlinear optical crystal 32 according to this embodiment is composed of a combination of a first wavelength conversion element (not shown) that generates a second harmonic having a wavelength higher than the wavelength of the fundamental wave (fundamental wavelength), and a second wavelength conversion element (not shown) that generates a third harmonic having a wavelength higher than the second harmonic.

[0086] The second harmonic is twice the frequency of the fundamental wave. In this embodiment, the wavelength of the second harmonic is set to 532 nm. The third harmonic is three times the frequency of the fundamental wave. In this embodiment, the wavelength of the third harmonic is set to 355 nm, which falls within the ultraviolet region.

[0087] In this embodiment, LBO(LiB3O3) is used as the first wavelength conversion element and the second wavelength conversion element. However, the first wavelength conversion element and / or the second wavelength conversion element are not limited to LBO(LiB3O3); various organic nonlinear optical materials, inorganic nonlinear optical materials, etc., can be used.

[0088] (Laser beam scanning unit 4) The laser beam scanning unit 4 is configured using a so-called two-axis (X-axis and Y-axis) galvanometer scanner, and includes a first scanner 41 as a Y scanner and a second scanner 42 as an X scanner.

[0089] The first scanner 41 has a first mirror 41a that reflects the UV laser light generated by the laser light output unit 3. The second scanner 42 has a second mirror 42a that reflects the UV laser light reflected by the first mirror 41a.

[0090] The laser beam scanning unit 4 drives the first mirror 41a and the second mirror 42a according to pre-created printing data, thereby polarizing the UV laser beam generated by the laser beam output unit 3 so that it is directed toward the irradiation area R1. The thus polarized UV laser beam passes through the emission window 6 and irradiates the irradiation area R1.

[0091] <Marker Controller 100> Figure 4 is a diagram illustrating the printing data Df for thick lines. Figure 5 is a diagram illustrating the basic concept of the scanning order according to this embodiment. As shown in Figure 2, the marker controller 100 includes a reception unit 101 that accepts the setting of printing conditions, a storage unit 102 that stores the printing conditions, a printing data generation unit 103 that generates printing data Dp based on the printing pattern Pp included in the printing conditions, a marking control unit 104 that controls the marker head 1 based on the printing data Dp, and a power supply unit 105 that supplies power to the marker head 1.

[0092] One or more of these elements may be provided in the operating terminal 300 (print setting device) or the marker head 1. For example, the print data generation unit 103 may be implemented in the operating terminal 300, or the power supply unit 105 may be provided in the marker head 1.

[0093] (Reception area 101) The reception unit 101 is configured to receive printing conditions set via the operation terminal 300 and to output the received printing conditions to the storage unit 102 and / or the print data generation unit 103.

[0094] Specifically, the reception unit 101 according to this embodiment is electrically connected to the operation terminal 300, displays a setting plane R2 on the display unit 301 as a display means, and places an input interface Iu as a character input means on the setting plane R2.

[0095] The reception unit 101 can reflect the content input through the input interface Iu into each printing condition and output the reflected printing conditions to the storage unit 102 and / or the marking control unit 104.

[0096] (Storage unit 102) The storage unit 102 is configured to temporarily or continuously store the printing conditions received by the reception unit 101, and to output the stored printing conditions to the printing data generation unit 103, the marking control unit 104, the display unit 301, etc., as needed.

[0097] Specifically, the storage unit 102 according to this embodiment is composed of non-volatile memory such as a hard disk drive (HDD) or solid state drive (SSD), or volatile memory, and can temporarily or continuously store data indicating print settings.

[0098] (Print data generation unit 103) The print data generation unit 103 generates print data Dp based on the print pattern Pp received by the input interface Iu as a character input means, in association with a setting plane R2 defined by orthogonal coordinates. This print data Dp is data having scan lines along the line elements of the characters to be marked. When the characters are to be thickened, the print data Dp can be called "thickened print data". The print data Dp as thickened print data Df has a plurality of scan lines aligned in the direction in which the line elements become thicker.

[0099] Specifically, the print data generation unit 103 according to this embodiment generates print data Dp by arranging multiple scan lines in the character width direction, which is perpendicular to the scanning direction of the print pattern Pp, so that the print pattern Pp is made thicker according to the character size of the print pattern Pp received as input by the input interface Iu. In this specification, "character width direction" means a direction perpendicular to each scan line, and can be various directions in each part of the scan line, such as left and right, up and down, diagonal, etc. The "character width direction" here does not mean a specific single direction, such as the direction of arrangement of characters in each document, or a direction perpendicular to that arrangement direction. In other words, the direction perpendicular to the scanning direction of the print pattern Pp is the direction perpendicular to each center line of the line elements that make up the character corresponding to the print pattern Dp, and can be said to be an example of the direction in which the line elements of the character become thicker.

[0100] In this context, the scan lines refer to the trajectory of the UV laser beam irradiation position on the surface of the workpiece W (particularly the surface within the irradiation area R1). These scan lines are set in accordance with the printing pattern Pp, and the shape of the scan lines changes according to the printing pattern Pp, as well as the number of scan lines changing according to the shape and thickness of the characters in the printing pattern Pp. The printing data Dp in this embodiment includes data indicating the number of scan lines and the shape of each scan line.

[0101] For example, as shown in the left diagram of Figure 4, if the print pattern Pp is set to the thinnest possible lowercase letter "l", the number of scan lines will be one, and the shape of that scan line will be a vertical line. In this case, the scanning direction of the print pattern Pp will be the direction in which the scan line extends (the vertical direction of the paper).

[0102] On the other hand, as shown in the center diagram of Figure 4, if a somewhat thickened lowercase "l" is set as the print pattern Pp, the number of scan lines will be odd, for example, and the shape of each scan line will be a vertical line. In this case, the odd number of scan lines will extend approximately parallel to each other. Also, the middle of the odd number of scan lines will approximately coincide with the center line of the character's line element (hereinafter also simply referred to as the "character's center line") Mc. In this case, the scanning direction of the print pattern Pp will be the direction in which the scan lines extend (vertical direction of the paper), and the character width direction, which is the direction in which the scan lines are arranged, will be the direction perpendicular to the direction in which the scan lines extend (horizontal direction of the paper).

[0103] Alternatively, as shown in the right-hand diagram of Figure 4, the number of scan lines may be even. In this case, the center line Mc of the character will extend between the two central scan lines of the even number of scan lines. As shown in the right-hand diagram of Figure 4, the center line Mc does not necessarily coincide with the scan lines.

[0104] In the following, among the print data Dp, print data Dp corresponding to the thickened print pattern Pp, that is, print data Dp with multiple scan lines, will be referred to as "thick-line print data," and may be denoted with the code "Df." The following explanation will describe the cases in which thick-line print data Df is generated as print data Dp.

[0105] The thick line printing data Df generated by the printing data generation unit 103 is either stored in the storage unit 102 or directly input to the marking control unit 104.

[0106] (Marking control unit 104) The marking control unit 104 controls the laser beam output unit 3 and the laser beam scanning unit 4 based on the print data Dp generated by the print data generation unit 103, thereby performing marking on the workpiece W placed on the irradiation area R1, which serves as the printing surface, using UV laser light.

[0107] For example, if thick line print data Df is generated as print data Dp, the marking control unit 104 reads the number of scan lines and the shape of each scan line that make up the thick line print data Df. Then, it scans the multiple scan lines one by one on the print surface in a predetermined scanning order (the order in which each scan line is scanned).

[0108] Generally, among the multiple scan lines that constitute the thick line print data Df, the scan lines adjacent to each other in the direction in which the aforementioned line element thickens (character width direction Dw) can be divided into inner scan lines (hereinafter referred to as "inner scan lines") Li that are relatively close to (or approximately coincide with) the character's center line Mc, and outer scan lines (hereinafter referred to as "outer scan lines") Lo that are relatively further away from the center line Mc compared to the inner scan lines Li. In this embodiment, the character width direction Dw is defined as the direction perpendicular to the center line Mc.

[0109] Here, as shown in Figure 5, consider the case where a lowercase "o" is input as the print pattern Pp, and the print data Df for thick lines corresponding to that print pattern Pp is set to a first scan line La having a circular shape, a second scan line Lb having a circular shape with a smaller diameter than the first scan line La, and a third scan line Lc having a circular shape with a smaller diameter than the second scan line Lb.

[0110] The first scan line La forms the outer contour of the character, the second scan line Lb extends along the character's centerline Mc, and the third scan line Lc forms the inner contour of the character. Furthermore, the circular shape of the first scan line La, the second scan line Lb, and the third scan line Lc is nothing other than a closed curve. Thus, the multiple scan lines constituting the thick line print data Df may include scan lines that form the contour (inner or outer contour) of the character, scan lines that extend along the character's centerline, and closed curves such as circles.

[0111] In this case, of the first scan line La, the second scan line Lb, and the third scan line Lc, the first scan line La and the second scan line Lb are adjacent, and the second scan line Lb and the third scan line Lc are adjacent.

[0112] Of the two possible pairs, for the pair of the first scan line La and the second scan line Lb, the first scan line La corresponds to the outer scan line Lo, and the second scan line Lb corresponds to the inner scan line Li. Similarly, for the pair of the second scan line Lb and the third scan line Lc, the second scan line Lb corresponds to the inner scan line Li, and the third scan line Lc corresponds to the outer scan line Lo.

[0113] The allocation of outer scan lines Lo and inner scan lines Li varies depending on the number of scan lines and the breakdown of pairs. For example, if a fourth scan line (not shown) exists further out than the first scan line La, then for the pair of that fourth scan line and the first scan line La, the fourth scan line will correspond to the outer scan line Lo, and the first scan line La will correspond to the inner scan line Li.

[0114] Furthermore, the marking control unit 104 according to this embodiment controls the laser beam scanning unit 4 so that, for each pair of adjacent scan lines in the character width direction Dw among the multiple scan lines constituting the thick line printing data Df, the UV laser beam is scanned along the outer scan line Lo before the inner scan line Li.

[0115] In the example shown in Figure 5, the marking control unit 104 scans the UV laser beam along one of the first scanning line La and the third scanning line Lc, and then scans the UV laser beam along the other of the first scanning line La and the third scanning line Lc. Subsequently, the marking control unit 104 scans the UV laser beam along the remaining second scanning line Lb.

[0116] The scanning order may be determined by the printing data generation unit 103 when generating the thick line printing data Df, and may be stored in the storage unit 102, etc., either in association with the thick line printing data Df or as one element of the thick line printing data Df. Alternatively, the marking control unit 104 may determine the scanning order each time the UV laser light is scanned.

[0117] Furthermore, the marking control unit 104 according to this embodiment controls the laser beam scanning unit 4 to scan the UV laser beam sequentially, starting with the scan lines that form the outline of the character corresponding to the thick line printing data Df, among the multiple scan lines that constitute the thick line printing data Df.

[0118] Specifically, in the example shown in Figure 5, the UV laser light is scanned sequentially from the first scan line La and the third scan line Lc as scan lines that form the outline of the character. Alternatively, consider a case where the first scan line La is located slightly inside the outer outline of the character, and the third scan line Lc is located slightly inside the inner outline of the character, and for example, there is a fourth scan line (not shown) that is further outside than the first scan line La and coincides with the outer outline of the character.

[0119] In this case, the marking control unit 104 will scan the UV laser beam sequentially starting with the fourth scan line that coincides with the outer contour, before the first scan line La and the third scan line Lc. The same applies if there is a fifth scan line (not shown) further inside than the third scan line Lc that coincides with the inner contour of the character. In this case, the marking control unit 104 will scan the UV laser beam sequentially starting with the fifth scan line that coincides with the inner contour, before the first scan line La and the third scan line Lc.

[0120] Furthermore, when multiple scanning lines include a closed curve and UV laser light is scanned along the closed curve, the marking control unit 104 controls the laser light scanning unit 4 to create a gap between the start and end points of the closed curve.

[0121] Specifically, in the example shown in Figure 5, the circular first scan line La, second scan line Lb, and third scan line Lc correspond to closed curves. In this case, a gap Gp is ​​provided between the circular start and end points corresponding to the first scan line La. Note that although a gap is provided between the start and end points of the closed curve in this example, it is not necessary to provide this gap. Furthermore, the width of the gap Gp can be adjusted by adjusting the ON / OFF state of the UV laser light.

[0122] Furthermore, the marking control unit 104 controls the laser beam scanning unit 4 so that in each of the multiple scanning lines that constitute the thick line printing data Df, the portion that constitutes the end of the character is divided.

[0123] For example, in the case of the lowercase letter "o" shown in Figure 5, it is not possible to define the ends of the letter in the first place, but in the case of the lowercase letter "l" shown in Figure 4, the upper and lower ends of the "l" correspond to the ends of the letter.

[0124] Furthermore, the marking control unit 104 according to this embodiment disconnects the portions corresponding to the upper and lower ends of the "l" for each of the multiple scan lines. In other words, both the upper and lower ends of the "l" are composed of two or more scan lines, rather than being drawn in a single stroke. This configuration will be explained later with reference to Examples 2-3 and 2-4.

[0125] Furthermore, the marking control unit 104 according to this embodiment can also be configured to control the laser beam scanning unit 4 so that, among the multiple scan lines constituting the thick line printing data Df, the scan lines that form the outline of the characters are scanned with UV laser light in an order that prioritizes them over other scan lines.

[0126] In this case, if the character to be marked, such as the number "0", has an outer contour and an inner contour, it is preferable that the marking control unit 104 first scans the scan line that forms one of the outer contour and the inner contour, and second scans the scan line that forms the other of the outer contour and the inner contour.

[0127] On the other hand, if the character to be marked, such as the number "1," only has an outer outline, the marking control unit 104 preferably scans the scan line that forms the outer outline first. However, the scan line that forms the outer outline may be scanned second or later.

[0128] Furthermore, if some of the multiple scan lines constituting the thick line printing data intersect, the marking control unit 104 may process the second and subsequent intersection points as invalid portions, and when the laser beam scanning unit 4 scans the invalid portions, it may control the laser beam output unit 3 so that a minute amount of laser beam is output compared to the non-invalid portions. Here, "minute amount of laser beam" refers to a laser beam with relatively small laser power.

[0129] Furthermore, when the workpiece W moves, workpiece movement information is input (either by user input or automatically). This includes, for example, the workpiece's movement speed, direction of movement, and encoder input pulses. Alternatively, it may include a trigger to determine the printing timing or a trigger delay to delay the printing timing. The marking control unit 104 may control the laser beam scanning unit 4 so that the multiple scan lines constituting the thick line printing data follow the movement of the workpiece, based at least on the movement speed and direction determined by the workpiece movement information.

[0130] The following provides specific examples of various printing patterns Pp, including scanning order and gaps Gp.

[0131] -Comparative Example and First Example of Scanning Order- Figure 6 shows a first comparative example of the scanning order. Figure 7 shows a first embodiment of the scanning order. Here, we consider the case where the number "0" is input as the print pattern Pp, and five scan lines arranged in the character width direction Dw are set as the thick line print data Df corresponding to the print pattern Pp.

[0132] The five scan lines can be referred to as the first scan line Le11, the second scan line Le12, the third scan line Le13, the fourth scan line Le14, and the fifth scan line Le15, in order from the scan line closest to the outer contour of the digit "0". Of the five scan lines, the third scan line Le13 roughly coincides with the center line of the character (not shown in the illustration), the first scan line Le11 roughly coincides with the outer contour of the character, and the fifth scan line Le15 roughly coincides with the inner contour of the character. Furthermore, the first scan line Le11 to the fifth scan line Le15 are all closed curves.

[0133] As shown in Figure 6, in the conventionally known scanning order, scanning is performed sequentially starting from the scan lines closest to the center line of the character, or sequentially starting from the scan lines closest to the inner contour of the character.

[0134] If the former scanning order (Comparative Example 1-1) is adopted, the marking control unit 104 will scan the UV laser light in the order of the third scanning line Le13, the second scanning line Le12, the fourth scanning line Le14, the first scanning line Le11, and the fifth scanning line Le15. In this case, the scanning order of the second scanning line Le12 and the fourth scanning line Le14, and the scanning order of the first scanning line Le11 and the fifth scanning line Le15 can be swapped.

[0135] When the latter scanning order (Comparative Example 1-2) is adopted, the marking control unit 104 scans the UV laser light in the order of the 5th scanning line Le15, the 4th scanning line Le14, the 3rd scanning line Le13, the 2nd scanning line Le12, and the 1st scanning line Le11.

[0136] On the other hand, in the scanning order according to this embodiment, in the pair of the first scan line Le11 and the second scan line Le12, the first scan line Le11 is scanned first; in the pair of the second scan line Le12 and the third scan line Le13, the second scan line Le12 is scanned first; in the pair of the third scan line Le13 and the fourth scan line Le14, the fourth scan line Le14 is scanned first; and in the pair of the fourth scan line Le14 and the fifth scan line Le15, the fifth scan line Le15 is scanned first.

[0137] If one example of the scanning order according to this embodiment (Example 1-1) is adopted, the marking control unit 104 will scan the UV laser light in the order of the first scanning line Le11, the fifth scanning line Le15, the second scanning line Le12, the fourth scanning line Le14, and the third scanning line Le13.

[0138] Furthermore, if another example of the scanning order according to this embodiment (Example 1-2) is adopted, the marking control unit 104 will scan the UV laser light in the order of the first scanning line Le11, the second scanning line Le12, the fifth scanning line Le15, the fourth scanning line Le14, and the third scanning line Le13. Also, since the first scanning line Le11 to the fifth scanning line Le15 are all closed curves, in Example 1-2, a gap Gp is ​​provided between the start and end points of the first scanning line Le11 to the fifth scanning line Le15.

[0139] Not limited to the examples in Examples 1-1 and 1-2, any scanning order can be adopted as long as it satisfies the priority order of each pair described above.

[0140] -Second Comparative Example and Second Example of Scanning Order- Figure 8 shows a second comparative example of the scanning order. Figure 9 shows a second embodiment of the scanning order. Here, we consider the case where the number "1" is input as the print pattern Pp, and three scan lines aligned in the character width direction Dw are set as the thick line print data Df corresponding to that print pattern Pp.

[0141] The three scan lines can be referred to as the first scan line Le21, the second scan line Le22, and the third scan line Le23, in order from the scan line closest to the outer contour of the number "1". Of the three scan lines, the third scan line Le23 roughly coincides with the center line of the character (not shown in the illustration), and the third scan line Le23 coincides with the outer contour of the character. In addition, both the first scan line Le21 and the second scan line Le22 ​​are closed curves.

[0142] As shown in Figure 9, in the conventionally known scanning order, the scan lines are scanned sequentially, starting with the scan line closest to the center line of the character.

[0143] When such a scanning order (Comparative Example 2) is adopted, the marking control unit 104 will scan the UV laser light in the order of the third scanning line Le23, the second scanning line Le22, and the first scanning line Le21.

[0144] On the other hand, in the scanning order according to this embodiment, in the pair of the first scan line Le21 and the second scan line Le22, the first scan line Le21 is scanned first, and in the pair of the second scan line Le22 ​​and the third scan line Le23, the second scan line Le22 ​​is scanned first.

[0145] If one example of the scanning order according to this embodiment (Example 2-1) is adopted, the marking control unit 104 will scan the UV laser light in the order of the first scanning line Le21, the second scanning line Le22, and the third scanning line Le23.

[0146] If another example of the scanning order according to this embodiment (Example 2-2) is adopted, the marking control unit 104 will scan the UV laser light in the order of the first scan line Le21, the third scan line Le23, and the second scan line Le22. In this case, the marking control unit 104 will scan the UV laser light along the first scan line Le21, which forms the outline of the character, with priority over the other scan lines (the second scan line Le22 ​​and the third scan line Le23).

[0147] Furthermore, unlike the number "0", the end of the character "1" can be defined. As shown by the dashed lines in Example 2-3, the first scan line Le21 and the second scan line Le22 ​​are divided into two at the upper and lower ends of the "1", respectively.

[0148] Therefore, if another example of the scanning order according to this embodiment (Example 2-3) is adopted, the marking control unit 104 will scan the UV laser light in the following order: one half of the divided first scanning line Le21, the other half of the divided first scanning line Le21, one half of the divided second scanning line Le22, the other half of the divided second scanning line Le22, and the third scanning line Le23.

[0149] Note that it is not necessary to split both the first scan line Le21 and the second scan line Le22 ​​into two; it is sufficient to split at least one scan line into two.

[0150] If, of the first scan line Le21 and the second scan line Le22, only the second scan line Le22 ​​is split into two, the marking control unit 104 will scan the UV laser light in the following order, as shown by the dashed line in another example of the scanning order (Example 2-4): first scan line Le21, one of the two split second scan lines Le22, the other of the two split second scan lines Le22, and then the third scan line Le23.

[0151] -Third example of scanning sequence- Figure 10 shows a third embodiment of the scanning sequence. Here, we consider the case where the number "8" is input as the print pattern Pp, and nine scan lines are set as the thick line print data Df corresponding to that print pattern Pp.

[0152] The nine scan lines can be designated as follows, in order from the scan line closest to the outer contour of the number "8": 1st scan line Le31, 2nd scan line Le32, 3rd scan line Le33, 4th scan line Le34, 5th scan line Le35, 6th scan line Le36, 7th scan line Le37, 8th scan line Le38, and 9th scan line Le39.

[0153] Of the nine scan lines, the first scan line Le31 and the second scan line Le32 are common to the upper and lower halves of the number "8". The third scan line Le33, the sixth scan line Le36, and the eighth scan line Le38 constitute the upper half of the number "8". The fourth scan line Le34, the seventh scan line Le37, and the ninth scan line Le39 constitute the lower half of the number "8". The fifth scan line Le35 is a scan line that connects the third scan line Le33 of the upper half and the fourth scan line Le34 of the lower half.

[0154] Furthermore, of the nine scan lines, the third scan line Le33, the fourth scan line Le34, and the fifth scan line Le35 roughly coincide with the center line Mc of the character, the first scan line Le31 roughly coincides with the outer contour of the character, the eighth scan line Le38 roughly coincides with the inner contour of the upper half, and the ninth scan line Le39 roughly coincides with the inner contour of the lower half. In addition, the scan lines other than the third scan line Le33, the fourth scan line Le34, and the fifth scan line Le35 form closed curves.

[0155] In the scanning order according to this embodiment, in the pair of the first scan line Le31 and the second scan line Le32, the first scan line Le31 is scanned first; in the pair of the second scan line Le32 and the third scan line Le33, the second scan line Le32 is scanned first; in the pair of the second scan line Le32 and the fourth scan line Le34, the second scan line Le32 is scanned first; in the pair of the third scan line Le33 and the sixth scan line Le36, the sixth scan line Le36 is scanned first; and in the pair of the fourth scan line Le34 and the seventh scan line Le37, the seventh scan line Le37 is scanned first.

[0156] Furthermore, in the pair of the 5th scan line Le35 and the 6th scan line Le36, the 6th scan line Le36 is scanned first; in the pair of the 5th scan line Le35 and the 7th scan line Le37, the 7th scan line Le37 is scanned first; in the pair of the 6th scan line Le36 and the 8th scan line Le38, the 8th scan line Le38 is scanned first; and in the pair of the 7th scan line Le37 and the 9th scan line Le39, the 9th scan line Le39 is scanned first.

[0157] If one example of the scanning order according to this embodiment (Example 3-1) is adopted, the marking control unit 104 will scan the UV laser light in the following order: first scan line Le31, eighth scan line Le38, ninth scan line Le39, second scan line Le32, sixth scan line Le36, seventh scan line Le37, third scan line Le33, fourth scan line Le34, and fifth scan line Le35.

[0158] Furthermore, if another example of the scanning order according to this embodiment (Example 3-2) is adopted, the marking control unit 104 will scan the UV laser light in the order of the first scan line Le31, the second scan line Le32, the eighth scan line Le38, the sixth scan line Le36, the third scan line Le33, the ninth scan line Le39, the seventh scan line Le37, the fourth scan line Le34, and the fifth scan line Le35.

[0159] (Power supply section 105) The power supply unit 105 supplies a drive current to the excitation photogenerator 2 based on the control signal output from the marking control unit 104. While details are omitted, the power supply unit 105 determines the drive current based on the target output input from the marking control unit 104, and then supplies the determined drive current to the excitation photogenerator 2 via the electrical cable 200. Details of the power supply unit 105 are omitted.

[0160] <About the main processing and user interface of the laser marking device L> Figure 11 is a flowchart illustrating the procedure for determining the scanning order. Figures 12 and 13 illustrate the user interface related to the scanning order, respectively. The main processes and user interface of the laser marking apparatus L will be explained below with reference to Figures 11 to 13.

[0161] First, in step S1 of Figure 11, the marker controller 100 displays the setting plane R2 on the display unit 301 and places an input interface Iu on the setting plane R2 to receive input of the print pattern Pp.

[0162] In step S1, the display unit 301 displays a screen as shown in Figures 12 and 13. In Figures 12 and 13, the first interface I1 is a toggle tab for displaying an input screen on which the setting plane R2 is positioned to accept input of print content (print pattern Pp). The second interface I2 is a toggle tab for displaying an enlarged view of the setting plane R2 to accept position adjustment of the print pattern Pp, and the third interface I3 is a toggle tab for displaying an input screen on which input fields for entering detailed settings of the print pattern Pp are positioned. Figure 12 corresponds to the state in which the first interface I1 is selected, and Figure 13 corresponds to the state in which the second interface I2 is selected.

[0163] Furthermore, the fourth interface I4 displayed in the upper right corner of the screen in Figure 12 displays the identification number (block No.) assigned to a print block, which is a collection of multiple print patterns Pp, and is a user interface for switching between print patterns Pp via that identification number.

[0164] Furthermore, the fifth interface I5 displayed on the left side of the screen in Figure 12 is a button for stopping the operation of the laser marking device L, the sixth interface I6 is a button for transitioning to an input screen for setting items that should be determined earlier than the printing pattern Pp, and the seventh interface I7 is a button for saving the contents of the printing pattern Pp to the storage unit 102, etc.

[0165] Furthermore, the eighth interface I8, displayed from the center to the right of the screen in Figure 12, is an input field that accepts input of print content (print pattern Pp), and constitutes the input interface Iu in this embodiment.

[0166] On the left side of the screen of the eighth interface I8, a ninth interface I9 composed of a setting plane R2 is displayed. This ninth interface I9 functions as a display column for displaying the layout of the printing pattern Pp and constitutes the input interface Iu in the present embodiment.

[0167] Also, in FIG. 12, on the lower side of the screen of the ninth interface I9, a tenth interface I for receiving an input of the character size of the printing pattern Pp 10 and an eleventh interface I for receiving an input of the character width of the printing pattern Pp 11 and a twelfth interface I for receiving an input of the thickness of the characters constituting the printing pattern Pp 12 are displayed.

[0168] On the other hand, in FIG. 13, a ninth interface I9 that is displayed in an enlarged view compared to the state shown in FIG. 12 is displayed. In the ninth interface I9 in FIG. 13, a thirteenth interface I showing the printing pattern Pp to be adjusted in position 13 and a fourteenth interface I showing a crosshair serving as a reference for position adjustment 14 are displayed. The thirteenth interface I 13 constitutes the input interface Iu in the present embodiment.

[0169] Also, in FIG. 13, on the right side of the screen of the ninth interface I9, a fifteenth interface I for moving the printing block within the setting plane R2 15 and a sixteenth interface I for adjusting the width of the entire printing block 16 and a seventeenth interface I for adjusting the height of the entire printing block 17 are displayed.

[0170] The first interface I1 to the seventeenth interface I 17 are all configured to receive an input via the operation unit 302.

[0171] Next, in step S2 of Figure 11, the marker controller 100 accepts the input of the print pattern Pp via the input interface Iu as shown in Figures 12 and 13. At this time, the marker controller 100 also accepts other settings that constitute the print data Dp, such as the thickness of the characters.

[0172] In the following step S3, the print data generation unit 103 generates print data Dp associated with the setting plane R2 based on the print pattern Pp received in step S2. In this step S3, the print data generation unit 103 generates thick line print data Df as print data Dp according to settings such as the thickness of the characters.

[0173] In the following step S4, as explained with reference to Figure 5, the print data generation unit 103 or the marking control unit 104 determines the positional relationship of each scan line with respect to the character's center line Mc. Specifically, in this step S4, the print data generation unit 103 or the marking control unit 104 classifies adjacent scan lines among the multiple scan lines into outer scan line Lo and inner scan line Li.

[0174] In the following step S5, the print data generation unit 103 or the marking control unit 104 determines the scanning order such that the outer scan line Lo is scanned before the inner scan line Li.

[0175] In the subsequent step S6, the marking control unit 104 scans the UV laser light along each scan line according to the scanning order determined in step S5.

[0176] As described above, the sheet-like film constituting the workpiece W contains a UV reaction layer X that chemically reacts with UV laser light. By scanning the workpiece W containing the UV reaction layer X with UV laser light, a marking corresponding to the printing pattern Pp is applied to the printing surface, which serves as the irradiation area R1. As suitable printing conditions for such a workpiece W, the laser light output unit 3 according to this embodiment adjusts the laser power of the UV laser light within a range of 0.8W to 1.6W. Note that the range of 0.8W to 1.6W is a preferred example, and the power may be adjusted outside this range.

[0177] Table 1 shows the type parameters when a general laminate film is used as the marking target, as an example of a workpiece W containing the UV reactive layer X. In Table 1, "No." in the first column indicates a number to identify each example. Examples A to C and comparative examples D to G are shown as examples in Table 1.

[0178] Furthermore, the second column, "Scanning Speed," indicates the scanning speed of the UV laser beam; the third column, "Frequency," indicates the Q-switch frequency; the fourth column, "Laser Power," indicates the laser power of the UV laser beam as described above; the fifth column, "Dot Size," indicates the spot diameter of the UV laser beam on the surface of the workpiece W; the sixth column, "Dot Spacing," indicates the spot spacing of the UV laser beam on the surface of the workpiece W; the seventh column, "1 Dot Power Density," indicates the power density of the UV laser beam per spot; and the eighth column, "1 Line Power Density," indicates the power density of the UV laser beam per scan line (more specifically, the value obtained by multiplying the 1 dot power density by the number of spots per unit length). The parameters shown in columns 2 to 8 are parameters that can be pre-set as the printing conditions described above.

[0179] The seventh column indicates the degree of damage inflicted by the UV laser light on the workpiece W. "GOOD" indicates relatively little damage, while "BAD" indicates relatively large damage. The eighth column indicates the visibility of the markings applied to the workpiece W. "GOOD" indicates relatively good visibility, while "BAD" indicates relatively poor visibility.

[0180] As shown in Table 1, Examples A to C excel in both damage and visibility, while Comparative Examples D to G are inferior in either damage or visibility. Specifically, when the 1-dot power density is high, as in Comparative Example D, the damage to the workpiece W is relatively large, so the 1-dot power density [mW / mm 2 It is preferable to set ] to 80 or less.

[0181] Furthermore, in the case of a high power density per line, as in Comparative Example E, the damage to the workpiece W becomes relatively larger, so it is preferable to set the power density per line [mW / mm] to 510 or less.

[0182] Furthermore, as in Comparative Example F, when the 1-dot power density is low, the color becomes fainter and visibility is poor, so the 1-dot power density [mW / mm²] is important. 2 It is preferable to set ] to 1.2 or higher.

[0183] Furthermore, as in Comparative Example G, when the 1-line power density is low, the color development becomes faint and visibility is poor, so it is preferable to set the 1-line power density [mW / mm] to 20 or higher.

[0184] In view of the above, the inventors of the present invention have determined that suitable printing conditions for a workpiece W containing a UV reactive layer X are a 1-dot power density [mW / mm²]. 2 We found that setting the power density [mW / mm] to a range of 1.2 to 80, and setting the 1-dot power density to a range of 20 to 510, is beneficial. As is clear from Table 1, the 1-dot power density and 1-line power density in Examples A to C are all set to fall within these ranges.

[0185] [Table 1]

[0186] <Regarding the improvement of the quality of bold line printing> As described above, according to this embodiment, the marking control unit 104 determines the scanning order of each scan line based on the center line Mc of the character. Specifically, for two adjacent scan lines, the outer scan line Lo, which is further away from the center line Mc, is scanned first (see Figure 5). As a result, the scan lines forming the outer contour are scanned in an earlier order than in the conventional method, enabling higher quality printing. Consequently, thick line printing with sufficient line width can be achieved more easily than before.

[0187] Furthermore, as shown in Figures 7, 9, and 10, the marking control unit 104 prioritizes scanning the scan lines that form the outer contour of the characters among the multiple scan lines that constitute the thick line printing data Df. This allows for high-quality printing of the character contours, and consequently, is advantageous in easily achieving thick line printing with sufficient line width compared to conventional methods.

[0188] Furthermore, as explained with reference to Table 1, the laser marking apparatus L according to this embodiment can be configured to be suitable for printing on a film containing a UV reactive layer X.

[0189] Furthermore, as shown in Figure 6, the marking control unit 104 divides the scan lines corresponding to the edges of the characters and excludes them from the UV laser irradiation target. Generally, degradation is more likely to occur at the edges of characters, so excluding such areas from the UV laser irradiation target is advantageous in improving the quality of thick line printing.

[0190] Furthermore, as shown in Figure 5, when a closed curve forming an inner contour or the like is included in the scan line, the marking control unit 104 does not directly connect the start and end points of the closed curve, but instead provides a gap Gp between them. This suppresses the occurrence of delamination and is advantageous in improving the quality of thick line printing.

[0191] Furthermore, as shown in Figure 9, the marking control unit 104 determines the scanning order of each scan line based on the character outline. Specifically, scan lines that form the outline of a character, such as the first scan line Le21 in Figure 9, are scanned with priority over other scan lines. As a result, the scan lines that form the outer outline are scanned earlier than before, enabling higher quality printing. Consequently, thick line printing with sufficient line width becomes easier to achieve than before.

[0192] <<Other Embodiments>> In the above embodiment, the procedure for setting the scanning order based on the character centerline Mc was described with reference to Figure 11, but this disclosure is not limited to the flow shown in Figure 11. The scanning order can also be set based on the flow shown in Figure 14.

[0193] For example, if the printing pattern Pp is the number "1" as shown in Figure 9, when thickening the line, the scanning lines are added in the order of the second scanning line Le22 ​​and the first scanning line Le21, starting from the single-line data (printing data Dp consisting of one scanning line) consisting only of the third scanning line Le23, and moving outwards. The marking control unit 104 according to this disclosure can set the scanning order to be the reverse of this scanning line addition order. In this case, the scanning lines will be scanned in the order of the first scanning line Le21, the second scanning line Le22, and the third scanning line Le23, starting with the earliest scanning timing. This scanning order matches the scanning order shown in Example 2-1 and prioritizes the scanning line that forms the outline of the character (first scanning line Le21).

[0194] Furthermore, if the printing pattern Pp is the number "0" as shown in Figure 7, for example, when thickening the line, scan lines will be added in the following order, starting from a single line data consisting only of the third scan line Le13: for example, the fourth scan line Le14, the second scan line Le12, the fifth scan line Le15, and the first scan line Le11. The marking control unit 104 according to this disclosure can set the scan order to be the reverse of this scan line addition order. In this case, each scan line will be scanned in the order of the earliest scanning timing: the first scan line Le11, the fifth scan line Le15, the second scan line Le12, the fourth scan line Le23, and the third scan line Le13. This scan order matches the scan order shown in Example 1-1.

[0195] Figure 14 is a flowchart showing another example of the procedure for determining the scanning order.

[0196] First, in step S101 of Figure 14, the marker controller 100 displays the setting plane R2 on the display unit 301 and places an input interface Iu on the setting plane R2 to receive input of the print pattern Pp.

[0197] Next, in step S102 of Figure 14, the marker controller 100 accepts the input of the print pattern Pp via the input interface Iu as shown in Figures 12 and 13. At this time, the marker controller 100 also accepts other settings that constitute the print data Dp, such as the thickness of the characters.

[0198] In the following step S103, the print data generation unit 103 generates print data Dp associated with the setting plane R2 based on the print pattern Pp received in step S102. In this step S103, the print data generation unit 103 generates print data Df for thick lines by adding scan lines outward from the single line data according to settings such as the thickness of the characters.

[0199] In the following step S104, as explained with reference to Figure 5, the print data generation unit 103 or the marking control unit 104 determines the scanning order so that it is in the reverse order of the scanning line addition used in step S103.

[0200] In the subsequent step S105, the marking control unit 104 scans the UV laser beam along each scan line according to the scanning order determined in step S104. This makes it easier to print thick lines with sufficient line width than in the conventional method, similar to the embodiment described above.

[0201] As previously described, the reception unit 101 and the print data generation unit 103 may be provided in the operation terminal 300, which functions as a print setting device. In this case, the operation terminal 300 is electrically connected to the laser marker, which consists of the marker head 1 and the marker controller 100. In this case, the operation terminal 300, which functions as a print setting device, includes a print data transmission unit that transmits the print data (print data for thick lines) generated by the print data generation unit 103 to the laser marker. [Explanation of Symbols]

[0202] S Laser Marking System L Laser Marking Device 1 Marker head 2. Excitation light generation unit 3. Laser light output section 4. Laser beam scanning unit 100 Marker Controllers 102 Storage section 103 Print Data Generation Unit 104 Marking Control Unit 300 Operating terminals 301 Display section (display means) Li inner scan line Lo outer scan line The center line of the letter Mc Dp Print Data Df Print data for thick lines Dw character width direction Gp gap Iu Input Interface (Character Input Method) R1 Irradiation area (printing surface) R2 setting plane Double job X UV reactive layer

Claims

1. A solid-state laser crystal that generates fundamental wave laser light based on excitation light, The system comprises a nonlinear optical crystal that generates UV laser light based on the fundamental wave laser light generated by the solid laser crystal, A laser light output unit that outputs UV laser light generated by the nonlinear optical crystal, A laser beam scanning unit scans the UV laser beam output from the laser beam output unit on the surface of the workpiece. A storage unit that stores print data having scan lines along the line elements of characters to be marked, and thick line print data having multiple scan lines arranged in the direction in which the line elements become thicker, A laser marking apparatus comprising: a marking control unit that controls the laser beam output unit and the laser beam scanning unit to mark characters by scanning UV laser light along the scanning lines of the print data stored in the storage unit, The marking control unit, When a character corresponding to the thick line printing data has an outer contour and an inner contour, the laser beam scanning unit is controlled so that, among the multiple scan lines constituting the thick line printing data, the scan line forming the outer contour of the character and the scan line forming the inner contour of the character are scanned with UV laser light before the scan line that is close to the center line of the character's line element. A laser marking apparatus characterized by the following features.

2. In the laser marking apparatus described in claim 1, A display means for displaying a set plane defined by a Cartesian coordinate system, A character input means is provided which is placed on the setting plane displayed by the display means and accepts input of characters to be marked, The system includes a print data generation unit that generates thick line print data having multiple scan lines arranged in a direction that thickens the line elements of the characters input by the character input means, The storage unit stores the thick line printing data generated by the printing data generation unit. A laser marking apparatus characterized by the following features.

3. In the laser marking apparatus according to claim 1 or 2, The direction in which the line element thickens is the direction perpendicular to the center line of the line element. A laser marking apparatus characterized by the following features.

4. In a laser marking apparatus according to any one of claims 1 to 3, The marking control unit, The laser beam scanning unit is controlled such that, among the multiple scan lines constituting the thick line printing data, one of the scan lines forming the outer contour of the character and the scan line forming the inner contour of the character is scanned with UV laser light first, and the other is scanned with UV laser light second. A laser marking apparatus characterized by the following features.

5. In the laser marking apparatus described in claim 4, The plurality of scan lines constituting the thick line printing data include scan lines that form the outline of the character. The marking control unit, The laser beam scanning unit is controlled to scan the UV laser beam sequentially, starting with the scan line that forms the outer contour of the character, among the multiple scan lines that constitute the thick line printing data. A laser marking apparatus characterized by the following features.

6. In the laser marking apparatus according to claim 4 or 5, The workpiece is composed of a sheet-like multilayer film, The multilayer film includes at least a surface layer, a UV reaction layer that chemically reacts with the UV laser light, and a sealant layer that sandwiches the UV reaction layer between itself and the surface layer. A laser marking apparatus characterized by the following features.

7. In a laser marking apparatus according to any one of claims 4 to 6, The plurality of scan lines constituting the thick line printing data include scan lines that extend along the center line of the character. A laser marking apparatus characterized by the following features.

8. In a laser marking apparatus according to any one of claims 4 to 7, The marking control unit, The laser beam scanning unit is controlled such that in each of the multiple scan lines constituting the thick line printing data, the portion constituting the end of the character is divided. A laser marking apparatus characterized by the following features.

9. In a laser marking apparatus according to any one of claims 4 to 8, The multiple scan lines that constitute the print data for the thick lines include closed curves. The marking control unit controls the laser beam scanning unit to create a gap between the start and end points of the closed curve when the UV laser beam is scanned along the closed curve. A laser marking apparatus characterized by the following features.

10. In a laser marking apparatus according to any one of claims 4 to 9, The laser output unit adjusts the laser power of the UV laser beam within the range of 0.8 W to 1.6 W. A laser marking apparatus characterized by the following features.

11. In a laser marking apparatus according to any one of claims 1 to 10, The marking control unit, If some of the multiple scan lines constituting the thick line printing data intersect, the second and subsequent intersection points are treated as invalid portions, and when the laser beam is scanned over these invalid portions by the laser beam scanning unit, the laser beam output unit is controlled so that a smaller amount of laser beam is output compared to the non-invalid portions. A laser marking apparatus characterized by the following features.

12. In a laser marking apparatus according to any one of claims 1 to 11, It is equipped with means for acquiring movement information of a moving workpiece, The marking control unit, Based on the movement speed and direction of the workpiece as determined by the workpiece movement information, the laser beam scanning unit is controlled so that the multiple scan lines constituting the thick line printing data follow the movement of the workpiece. A laser marking apparatus characterized by the following features.

13. A marking method for marking characters on the surface of a workpiece using a laser marking apparatus comprising: a solid laser crystal that generates fundamental wave laser light based on excitation light; a nonlinear optical crystal that generates UV laser light based on the fundamental wave laser light generated by the solid laser crystal; a laser light output unit that outputs UV laser light generated by the nonlinear optical crystal; a laser light scanning unit that scans the UV laser light output from the laser light output unit on the surface of a workpiece; a storage unit that stores thick line printing data having scan lines along the line elements of characters to be marked, wherein the scan lines are arranged in a direction that makes the line elements of the characters thicker; and a marking control unit that controls the laser light output unit and the laser light scanning unit to scan the UV laser light along the scan lines of the printing data based on the printing data stored in the storage unit to mark the characters; The marking control unit controls the laser beam output unit and the laser beam scanning unit so that, when a character corresponding to the thick line printing data has an outer contour and an inner contour, the UV laser beam is scanned before the scan lines that are close to the center line of the line element of the character, among the multiple scan lines constituting the thick line printing data, for the scan lines that form the outer contour of the character and the scan lines that form the inner contour of the character. A marking method characterized by the following.

14. A printing setting device is connected to a laser marker comprising a solid laser crystal that generates fundamental wave laser light based on excitation light, a nonlinear optical crystal that generates UV laser light based on the fundamental wave laser light generated by the solid laser crystal, a laser light output unit that outputs UV laser light generated by the nonlinear optical crystal, and a laser light scanning unit that scans the UV laser light output from the laser light output unit on the surface of a workpiece, and the laser light scanning unit generates printing data having scanning lines along the line elements of characters to be marked, A display means for displaying a set plane defined by a Cartesian coordinate system, A character input means is provided which is placed on the setting plane displayed by the display means and accepts input of characters to be marked, A print data generation unit generates thick line print data having multiple scan lines arranged in a direction that makes the line elements of the characters input by the character input means thicker, The system includes a print data transmission unit that transmits the thick line print data generated by the print data generation unit to the laser marker, The print data generation unit, When a character corresponding to the aforementioned thick line printing data has an outer and inner contour, the thick line printing data is generated such that, among the multiple scan lines constituting the thick line printing data, the scan lines forming the outer contour of the character and the scan lines forming the inner contour of the character are scanned by UV laser light before the scan lines adjacent to the center line of the character's line elements. A printing setting device characterized by the following features.

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