Laser Marker Device

Abstract

To provide a laser marker device capable of keeping constant printing quality, when printing a pattern in which there is variation in a degree of coarseness and fineness of a printing pattern, to various printing objects.SOLUTION: A laser marker device is a laser marker device for printing by radiating a laser beam to a printing object, and comprises: a laser oscillator for oscillating the laser beam; and a control unit for controlling the laser beam oscillated from the laser oscillator. The control unit corrects the printing pattern on the basis of material characteristics of the printing object and a degree of coarseness and fineness of a set printing pattern, for generating a corrected printing pattern, then controls the laser beam oscillated from the laser oscillator and draws the corrected printing pattern on the printing object.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a laser marker device.

Background Art

[0002] There is known a laser marker device that uses high energy obtained by condensing laser light to melt, burn, or peel the surface of a printing object, and prints information such as characters like dates and manufacturing numbers, two-dimensional codes, and figures on the object (see Patent Document 1). Patent Document 1 discloses a technique of dividing each of a character area, an image area, and a graphic area such as a frame line included in a marking area into individual rectangular areas, performing marking by vector scanning of a laser on the character area and the graphic area such as a frame line, and performing marking by raster scanning of a laser on the image area.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] [[ID=...]] When marking patterns consisting of multiple printing patterns (characters, figures, symbols, etc.) include both sparse and dense printing patterns, keeping the printing parameters constant may result in variations in printing quality, such as line thickness and density, among the multiple marked patterns. When laser light is shone onto an object to be printed, the object absorbs the energy and is printed. Therefore, even with the same printing parameters set, the visibility after printing will vary greatly depending on whether the object has a high or low absorption rate. For example, if the printing parameters (laser power, laser repetition frequency, scan speed, printing resolution, etc.) are optimized to achieve high visibility for sparse printing patterns, heat from the laser will tend to accumulate more easily with dense printing patterns. As a result, depending on the material of the object to be printed, the printed line width may become thicker or blurred, reducing visibility. On the other hand, if the printing parameters are optimized to achieve high visibility for dense printing patterns, then with sparse printing patterns, the print line width becomes thinner or lighter, resulting in reduced visibility.

[0005] To ensure consistent print quality, it is possible to manually adjust the printing parameters according to the density of the print pattern. However, this requires the experience and effort of the laser marker device user. Therefore, there is a demand for a laser marker device that can mark with consistent print quality regardless of the user.

[0006] The present invention aims to provide a laser marker device that can maintain consistent print quality when printing patterns with varying degrees of density on various printing targets. [Means for solving the problem]

[0007] A laser marker device according to one aspect of the present invention is a laser marker device that performs printing by irradiating a printing target with laser light, comprising: a laser oscillator that emits laser light; and a control device that controls the laser light emitted from the laser oscillator. The control device calculates the degree of sparseness or sparseness of the arrangement of line segments constituting a set printing pattern, determines whether the set printing pattern is sparse or dense based on the degree of sparseness or sparseness, and if it is determined that the printing pattern is dense, based on the material properties of the printing target, The print line width is calculated, and if the calculated print line width is greater than a predetermined reference width, the width of the line segments constituting the print pattern becomes narrower as the difference between the print line width and the reference width increases. The entire line segment constituting the aforementioned printing pattern of Thin ku supplement A corrected printing pattern is generated by correcting the error, and the laser light emitted from the laser oscillator is controlled based on the generated corrected printing pattern to draw the corrected printing pattern on the object to be printed. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a laser marker device that can maintain consistent print quality when printing patterns with varying degrees of density on various printing targets. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a configuration diagram of a laser marker device according to the first embodiment. [Figure 2A] Figure 2A shows an example of a marking pattern formed on an object to be printed on. [Figure 2B] Figure 2B shows another example of a marking pattern formed on an object to be printed on. [Figure 3] Figure 3 is a functional block diagram of the control device according to the first embodiment. [Figure 4] Figure 4 shows the material table of the object to be printed. [Figure 5] Figure 5 shows a material properties table. [Figure 6]FIG. 6 is a flowchart showing an example of the flow of printing control processing executed by the control device according to the first embodiment. [Figure 7] FIG. 7 is a diagram showing a selection screen for the material of the printing object. [Figure 8A] FIG. 8A is a diagram showing an example of a printing pattern area and a printing pattern. [Figure 8B] FIG. 8B is a diagram showing another example of a printing pattern area and a printing pattern. [Figure 9A] FIG. 9A is a diagram showing an example of the interval between line segments of the printing pattern. [Figure 9B] FIG. 9B is a diagram showing another example of the interval between line segments of the printing pattern. [Figure 10A] FIG. 10A is a diagram showing an example of a preview screen of the display device. [Figure 10B] FIG. 10B is a diagram showing another example of a preview screen of the display device. [Figure 11] FIG. 11 is a diagram showing a modified example of the preview screen of the display device. [Figure 12] FIG. 12 is a configuration diagram of the laser marker device according to the second embodiment. [Figure 13] FIG. 13 is a flowchart showing an example of the flow of printing control processing executed by the control device according to the second embodiment. [Figure 14A] FIG. 14A is a diagram showing an example of a printing pattern area and a printing pattern in the beam modulation unit. [Figure 14B] FIG. 14B is a diagram showing another example of a printing pattern area and a printing pattern in the beam modulation unit. [Figure 15A] FIG. 15A is a diagram showing an example of the interval between line segments of the printing pattern in the beam modulation unit. [Figure 15B] FIG. 15B is a diagram showing another example of the interval between line segments of the printing pattern in the beam modulation unit. [Figure 16] FIG. 16 is a diagram for explaining the correction processing executed by the control device according to the first modified example of the second embodiment. [Figure 17] FIG. 17 is a diagram for explaining correction processing executed by a control device according to Modification 2 of the second embodiment. [Figure 18] FIG. 18 is a diagram for explaining correction processing executed by a control device according to Modification 3 of the second embodiment. [Figure 19] FIG. 19 is a diagram showing a selection screen of a material of a printing object displayed on a display device based on a control signal of a control device according to Modification 1-1. [Figure 20] FIG. 20 is a diagram showing a selection screen of a material of a printing object displayed on a display device based on a control signal of a control device according to Modification 1-2.

Mode for Carrying Out the Invention

[0010] <First Embodiment> The laser marker device 100 according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 10B.

[0011] FIG. 1 is a configuration diagram of the laser marker device 100 according to the first embodiment. As shown in FIG. 1, the laser marker device 100 is a device that irradiates a printing object 6 with laser light (laser beam) to print a marking pattern such as a character string. The laser marker device 100 includes a laser device 110 that outputs laser light, a control device 120 that controls the laser device 110, and a setting device 130 that sets output conditions of the laser and the like.

[0012] The laser device 110 includes a laser oscillator (laser light source) 1, a beam diameter adjustment unit 2, a galvanometer scanner 111, and a beam irradiation unit 5. The laser oscillator 1 oscillates laser light based on a control signal from the control device 120. The type of the laser oscillator 1 is not particularly limited. The laser oscillator 1 is, for example, a solid-state laser such as a YAG laser or a gas laser such as a CO2 laser. The laser light from the laser oscillator 1 may be pulsed light or continuous light.

[0013] The beam diameter adjustment unit 2 adjusts the diameter of the laser beam emitted from the laser oscillator 1 (hereinafter also referred to as the beam diameter).

[0014] The galvanometer scanner 111 scans the laser beam emitted from the laser oscillator 1 in two dimensions in the X-axis direction and the Y-axis direction which is orthogonal to the X-axis direction. The galvanometer scanner 111 has a first laser beam scanning unit 3 that scans the laser beam in the X-axis direction and a second laser beam scanning unit 4 that scans the laser beam in the Y-axis direction. The first laser beam scanning unit 3 has a first scanning mirror and a first galvanometer motor, and the first scanning mirror is rotated by driving the first galvanometer motor. As the first scanning mirror rotates, the laser beam is scanned in the X-axis direction. The second laser beam scanning unit 4 has a second scanning mirror and a second galvanometer motor, and the second scanning mirror is rotated by driving the second galvanometer motor. As the second scanning mirror rotates, the laser beam is scanned in the Y-axis direction.

[0015] The beam irradiation unit 5 has a focusing lens (fθ lens) and focuses the laser light scanned in two dimensions by the galvanometer scanner 111 and irradiates the scanning area of ​​the object to be printed 6. Therefore, in the laser device 110 according to this embodiment, the laser light (laser beam) irradiated onto the object to be printed 6 by the beam irradiation unit 5 is scanned in two dimensions in the X-axis and Y-axis directions by the galvanometer scanner 111.

[0016] The control device 120 consists of a computer equipped with processing units 121 such as a CPU (Central Processing Unit), MPU (Micro Processing Unit), and DSP (Digital Signal Processor), non-volatile memory 122 such as ROM (Read Only Memory), flash memory, and hard disk drive, volatile memory 123 known as RAM (Random Access Memory), input interfaces, output interfaces, and other peripheral circuits. These hardware components work together to run software and realize multiple functions. The control device 120 may consist of one computer or multiple computers.

[0017] The non-volatile memory 122 stores a program capable of performing various calculations. In other words, the non-volatile memory 122 is a storage medium (device) from which the program realizing the functions of this embodiment can be read. The volatile memory 123 is a storage medium (device) that temporarily stores the calculation results from the processing unit 121 and signals input from the input interface. The processing unit 121 is a device that loads the program stored in the non-volatile memory 122 into the volatile memory 123 and performs calculations, and performs predetermined calculation processing on data taken in from the input interface, the non-volatile memory 122 and the volatile memory 123 according to the program.

[0018] The input interface converts signals received from the setting device 130, etc., into data that can be processed by the processing device 121. The output interface generates output signals according to the calculation results of the processing device 121 and outputs these signals to the various drive units of the laser device 110 (laser oscillator 1, first and second galvanometer motors, etc.) and the setting device 130, etc.

[0019] The setting device 130 includes an input device 131 operated by the user and a display device 132 that displays an image on a display screen. The display device 132 is a monitor such as a liquid crystal display. The input device 131 is an operating device such as a keyboard or mouse. The input device 131 may also be a touch sensor provided on the display screen of the display device 132.

[0020] The laser marker device 100 prints a marking pattern on the object to be printed 6 based on the marking pattern set by the setting device 130. Here, "printing" refers to irradiating the object to be printed 6 with laser light to form a marking pattern, i.e., laser processing. The marking pattern consists of one or more printing patterns. The printing patterns include letters, symbols such as marks, and patterns.

[0021] Figure 2A shows an example of a marking pattern formed on the object to be printed 6, and Figure 2B shows another example of a marking pattern formed on the object to be printed 6. When the thermal conductivity of the object to be printed 6 is assumed, highly visible marking patterns 61a and 61b are formed as shown in Figure 2A. The upper marking pattern 61a is composed of four printing patterns 62, and the lower marking pattern 61b is composed of eight printing patterns 62.

[0022] In contrast, if the thermal conductivity of the object to be printed 6 is greater than expected, a marking pattern 63a with low visibility may be formed, as shown in Figure 2B. The upper marking pattern 63a is composed of four printing patterns 64, and the lower marking pattern 63b is composed of eight printing patterns 64. In the example shown in Figure 2B, the heat from the laser is transmitted not only to the line segments that make up the upper marking pattern 63a, but also to the gaps between the line segments, causing the width of the printed line segments (printed line width) to be larger than the set value. As a result, in the upper marking pattern 63a, multiple line segments that should be independent are not separated but become integrated, reducing visibility. The lower marking pattern 63b, however, has wider spacing between the line segments, so the line segments do not become integrated, resulting in high visibility.

[0023] Thus, when the spacing between line segments is small, i.e., when the density of line segments is high, the visibility of the printed marking pattern may deteriorate. Conventionally, users have improved visibility by adjusting the printing parameters (laser power, laser repetition frequency, scan speed, print resolution, etc.). However, adjusting to the appropriate printing parameters according to the object to be printed 6 requires the user's experience and effort.

[0024] Therefore, in this embodiment, the control device 120 corrects the printing pattern based on the degree of density of the set printing pattern and the material properties (thermal conductivity) of the object to be printed 6, generates a corrected printing pattern, and controls the laser light emitted from the laser oscillator 1 to draw the corrected printing pattern on the object to be printed 6. The functions of the control device 120 according to this embodiment will be described in detail below.

[0025] Figure 3 is a functional block diagram of the control device 120. As shown in Figure 3, the control device 120 has the functions of a print coordinate generation unit 140, a coordinate storage unit 144, a print control unit 145, a parameter setting unit 146, a parameter storage unit 147, and a display control unit 148. The print coordinate generation unit 140 has an initial coordinate setting unit 141, a coordinate correction unit 142, a characteristic storage unit 143, and a pattern database 149.

[0026] The parameter storage unit 147 stores the printing parameters, the material table 71 of the object to be printed 6 (see Figure 4), the density threshold De0, and the interval threshold d0. The parameter setting unit 146 sets various parameters such as the printing parameters, the material table of the object to be printed 6, the density threshold De0, and the interval threshold d0 based on the input signal from the input device 131.

[0027] Printing parameters include laser power [W], laser repetition frequency [kHz], scan speed [mm / s], and print resolution [dots / mm]. Repetition frequency refers to the number of pulsed laser pulses generated per second at a constant cycle. These printing parameters can be changed by the user operating the input device 131. When the parameter setting unit 146 receives printing parameter information from the input device 131, it updates the setting values ​​of the printing parameters stored in the parameter storage unit 147 based on the input information.

[0028] Figure 4 shows the material table 71 for the printable object 6. The material table 71 for the printable object 6 is a data table that associates the type of material of the printable object 6 with its material property, thermal conductivity [W / m·K]. The types of materials for the printable object 6 include resin materials such as polyvinyl chloride resin (PVC), polyvinyl acetate resin (PVAC), polyvinyl alcohol (PVAL), polycarbonate (PC), polyvinyl butyral (PVB), polystyrene (PS), ABS resin (ABS), polymethyl methacrylate (PMMA), polyphenylene oxide (PPO), and polyurethane (PUR). The types of materials for the printable object 6 also include metal materials such as aluminum, stainless steel, iron, and copper. Furthermore, the types of materials for the printable object 6 also include glass materials such as soda-lime glass, quartz glass, and aluminosilicate glass.

[0029] The material table 71 can be modified by the user operating the input device 131. For example, when a new material type and its thermal conductivity are input from the input device 131, the parameter setting unit 146 adds the newly input information to the material table 71. Also, when information about a change in thermal conductivity is input for a material type that is already stored, the parameter setting unit 146 updates the thermal conductivity of the material stored in the parameter storage unit 147. The parameter setting unit 146 may also obtain new material types and their thermal conductivity via the internet and update the material table 71.

[0030] The characteristic memory unit 143 shown in Figure 3 stores the material characteristic table 143a. Figure 5 is a diagram of the material characteristic table 143a. In Figure 5, the horizontal axis represents thermal conductivity [W / m·K], and the vertical axis represents the print line width [μm]. The material characteristic table 143a is a data table that defines the relationship between the thermal conductivity of the object to be printed 6 and the print line width. The material characteristic table 143a is determined by performing a printing process on objects 6 of various materials with a predetermined line width (reference width) as a set value, and then determining the relationship between the measured print line width (actual width) and the thermal conductivity of the object to be printed 6. At a predetermined thermal conductivity (reference thermal conductivity), the actual width matches the reference width. For materials with a thermal conductivity greater than the reference thermal conductivity, the actual width is greater than the reference width. Also, for materials with a thermal conductivity less than the reference thermal conductivity, the actual width is smaller than the reference width. The print line width defined by material properties table 143a is a correction parameter used in the correction process described later.

[0031] The initial coordinate setting unit 141 shown in Figure 3 sets the printing pattern that constitutes a marking pattern such as a string of characters based on the input signal from the input device 131. Specifically, the initial coordinate setting unit 141 sets the initial coordinates of the line segments that constitute the printing pattern. The initial coordinates set by the initial coordinate setting unit 141 are the X-axis coordinate and the Y-axis coordinate. The pattern database 149 stores the printing pattern and the coordinate data set in association for each of the multiple printing patterns. The initial coordinate setting unit 141 reads the coordinate data set associated with the set printing pattern from the pattern database 149 and sets it as the initial coordinate.

[0032] The coordinate correction unit 142 calculates the degree of density of the print pattern set by the initial coordinate setting unit 141. Based on the calculated degree of density, the coordinate correction unit 142 determines whether the set print pattern is sparse or dense. Based on the determination result of whether the set print pattern is sparse or dense, the coordinate correction unit 142 decides whether or not to correct the set print pattern. If the coordinate correction unit 142 decides to correct the set print pattern, it corrects the initial coordinates that constitute the set print pattern based on the material properties of the object to be printed 6 and generates a corrected print pattern. The corrected coordinates that constitute the corrected print pattern are stored in the coordinate storage unit 144 as print coordinates. If the coordinate correction unit 142 decides not to correct the set print pattern, it stores the initial coordinates in the coordinate storage unit 144 as print coordinates without generating a corrected print pattern.

[0033] The coordinate correction unit 142 refers to the material property table 143a stored in the property storage unit 143 and calculates the print line width as a correction parameter based on the material properties of the print target object 6 selected by the user. If the calculated print line width is greater than the reference width, the coordinate correction unit 142 corrects the initial coordinates so that the width of the line segments of the print pattern becomes narrower as the difference between the print line width and the reference width increases. It is preferable that the coordinate correction unit 142 takes into account the deviation of the setting value of the print parameter that affects the print line width when making corrections. For example, if the setting value of the laser power is greater than the reference value, it is preferable to correct the initial coordinates so that the print line width is narrowed by that amount.

[0034] The display control unit 148 displays a predicted image (hereinafter referred to as a preview image) of the marking pattern after laser processing on the display screen of the display device 132, based on the print coordinates and print parameters stored in the coordinate storage unit 144.

[0035] The printing control unit 145 controls the laser beam emitted from the laser oscillator 1 by controlling the operation of the beam diameter adjustment unit 2 and the galvanometer scanner 111 of the laser device 110 based on the printing coordinates stored in the coordinate storage unit 144. As a result, a marking pattern containing multiple printing patterns is drawn on the object to be printed 6. In other words, if the printing control unit 145 decides not to correct the set printing pattern, it controls the laser beam emitted from the laser oscillator 1 based on the set printing pattern (initial coordinates) to draw the set printing pattern on the object to be printed 6. On the other hand, if the printing control unit 145 decides to correct the set printing pattern, it controls the laser beam emitted from the laser oscillator 1 based on the corrected printing pattern (corrected coordinates) to draw the corrected printing pattern on the object to be printed 6.

[0036] Figure 6 is a flowchart showing an example of the print control process performed by the control device 120. The flowchart shown in Figure 6 is started, for example, when the start switch of the laser marker device 100 is turned on.

[0037] In step S110, the parameter setting unit 146 sets the material of the object to be printed 6, the density threshold De0, and the spacing threshold d0 based on the input signal from the input device 131.

[0038] Figure 7 shows the material selection screen 160 for the object to be printed 6. As shown in Figure 7, the material selection screen 160 for the object to be printed 6 displays the material types from the material table 71 stored in the parameter storage unit 147. The display mode of the selection screen 160 in this embodiment is a hierarchical display mode. The material types are classified into metal materials, glass materials, and resin materials, and when each classification is selected, the material types of the selected classification are displayed. When the user wants to change the material, they select the material type using the input device 131. When a material type is selected, the parameter setting unit 146 stores the selected material type in the parameter storage unit 147. For example, the parameter setting unit 146 turns on the setting flag corresponding to the selected material type and turns off the setting flags corresponding to other material types. Since material properties are defined according to the material type (see Figure 4), the input device 131 of the setting device 130 functions as a selection device that selects one from among the material properties of multiple objects to be printed 6 stored in the control device 120.

[0039] When the user wishes to change the thresholds, they input the density threshold De0 and interval threshold d0 using the input device 131 shown in Figure 3. When the parameter setting unit 146 receives the input density threshold De0 and interval threshold d0, it sets the input density threshold De0 and interval threshold d0 in the parameter storage unit 147. In other words, it updates the thresholds that are pre-stored in the parameter storage unit 147 to the input values. Once the update is complete, the process proceeds to step S115 shown in Figure 6. If the user does not wish to change the density threshold De0 and interval threshold d0 that are pre-stored in the parameter storage unit 147, they perform a skip operation using the input device 131 without changing the thresholds. In this case, the parameter setting unit 146 proceeds to step S115 without changing the thresholds.

[0040] In step S115, the initial coordinate setting unit 141 generates initial coordinates based on the input signal from the input device 131. The user inputs a marking pattern, such as a string of characters to be printed, using the input device 131. The initial coordinate setting unit 141 sets the marking pattern based on the input signal from the input device 131. The marking pattern consists of one or more print patterns. The initial coordinate setting unit 141 obtains a set of coordinate data defined for each print pattern from the pattern database 149 and sets it as the initial coordinates for the print pattern.

[0041] Once the initial coordinates of the marking pattern are set, a loop process is executed that repeatedly performs the steps between steps S117 and S157. This loop process terminates when processing is completed for all the print patterns that make up the marking pattern.

[0042] In step S120, the coordinate correction unit 142 calculates the area Sa of the printing pattern region based on the initial coordinates of the marking pattern set in step S115. Specifically, as shown in Figures 8A and 8B, the coordinate correction unit 142 calculates the area (hereinafter also referred to as region area) Sa of the printing pattern region 161A, 161B, which is enclosed by a rectangle formed by connecting the outermost coordinates of the line segments constituting the set printing pattern. The outermost coordinates refer to the outermost coordinates in the X-axis direction and the outermost coordinates in the Y-axis direction of the printing pattern. The printing pattern region 161A, 161B is formed by a pair of straight lines parallel to the X-axis direction passing through the outermost coordinates in the Y-axis direction and a pair of straight lines parallel to the Y-axis direction passing through the outermost coordinates in the X-axis direction. Once the processing in step S120 shown in Figure 6 is completed, the process proceeds to step S125.

[0043] In step S125, the coordinate correction unit 142 calculates the total area (hereinafter also referred to as the line segment area) S of the line segments (the black-filled parts shown) within the print pattern areas 161A and 161B shown in Figures 8A and 8B. Specifically, the coordinate correction unit 142 calculates the total area S based on the coordinate data group that constitutes the print pattern. Once the processing in step S125 shown in Figure 6 is completed, the process proceeds to step S130.

[0044] In step S130, the coordinate correction unit 142 calculates the line segment density De by dividing the line segment area S calculated in step S125 by the region area Sa calculated in step S120 (De = S / Sa). The line segment density De corresponds to the proportion that the line segment area S occupies within the region area Sa. The line segment density De is the first parameter that represents the degree of density of the printed pattern. Once the processing in step S130 is completed, the process proceeds to step S135.

[0045] In step S135, the coordinate correction unit 142 performs a first density determination process to determine whether the set printing pattern is sparse or dense. In the first density determination process, the coordinate correction unit 142 determines whether the line segment density De calculated in step S130 is less than the density threshold De0 set in step S110. If the line segment density De is less than the density threshold De0, the coordinate correction unit 142 determines that the printing pattern is sparse and proceeds to step S140. If the line segment density De is greater than or equal to the density threshold De0, the coordinate correction unit 142 determines that the printing pattern is dense and proceeds to step S150.

[0046] In step S140, the coordinate correction unit 142 calculates the spacing between line segments that constitute the print pattern, as shown in Figures 9A and 9B. The spacing between line segments includes the distance between line segments in the X-axis direction and the distance between line segments in the Y-axis direction. The coordinate correction unit 142 sets the minimum value of the calculated spacing as the spacing parameter d, which represents the spacing between line segments that constitute the set print pattern. The spacing parameter d is a second parameter that represents the degree of density of the print pattern. Once the processing in step S140 shown in Figure 6 is completed, the process proceeds to step S145.

[0047] In step S145, the coordinate correction unit 142 performs a second density determination process to determine whether the set printing pattern is sparse or dense. In the second density determination process, the coordinate correction unit 142 determines whether the interval parameter d calculated in step S140 is greater than or equal to the interval threshold d0 set in step S110. If the interval parameter d is greater than or equal to the interval threshold d0, the coordinate correction unit 142 determines that the printing pattern is sparse and proceeds to step S157. If the interval parameter d is less than the interval threshold d0, the coordinate correction unit 142 determines that the printing pattern is dense and proceeds to step S150.

[0048] In step S150, the coordinate correction unit 142 corrects the print pattern based on the material properties of the object to be printed 6 so that the gaps between the line segments constituting the print pattern drawn on the object to be printed 6 are visible. As a result, a corrected print pattern is generated, and the process proceeds to step S157.

[0049] The coordinate correction unit 142 corrects the initial coordinates that constitute the set printing pattern, and the printing pattern composed of the corrected coordinates is designated as the corrected printing pattern. The coordinate correction unit 142 refers to the material properties table 143a and calculates the printing line width Lw corresponding to the thermal conductivity of the object to be printed 6 set in step S110. If the printing line width Lw is greater than a predetermined reference width Lw0, the coordinate correction unit 142 corrects the initial coordinates so as to narrow the current line width (set line width) defined by the initial coordinates. In other words, the coordinate correction unit 142 performs a correction to make the line segments thinner.

[0050] In step S157, the coordinate correction unit 142 determines whether processing has been completed for all printing patterns constituting the marking pattern. If it is determined that processing has been completed for all printing patterns constituting the marking pattern, the process proceeds to step S160. If it is determined that processing has not been completed for all printing patterns constituting the marking pattern, the process returns to step S117.

[0051] In step S160, the display control unit 148 displays a preview screen 170 of the marking pattern on the display screen of the display device 132. Figure 10A is a diagram showing an example of the preview screen 170 of the display device 132, and Figure 10B is a diagram showing another example of the preview screen 170 of the display device 132. As shown in Figures 10A and 10B, the preview screen 170 includes a preview image 171A, 171B of the marking pattern, a setting image 172 of the marking pattern, a setting image 173 of the print parameters, a print execution button 174, and a reset button 175.

[0052] While the preview screen 170 is displayed, the control device 120 accepts print execution operations and reset operations. For example, if the user determines that the visibility of the preview image 171A on the preview screen 170 shown in Figure 10A is poor, they perform a reset operation using the input device 131. If a reset operation is performed on the input device 131 in step S165 shown in Figure 6, the process returns to step S110. In this case, the user can improve the visibility of the marking pattern by changing the density threshold De0 and the interval threshold d0. Alternatively, for example, if the user determines that the visibility of the preview image 171B on the preview screen 170 shown in Figure 10B is good, they perform a print execution operation using the input device 131. If a print execution operation is performed on the input device 131 in step S165 shown in Figure 6, the process proceeds to step S170.

[0053] In step S170, the printing control unit 145 controls the laser light emitted from the laser oscillator 1 to draw a marking pattern based on the printing coordinates (initial coordinates or corrected coordinates) stored in the coordinate storage unit 144. The process of drawing the marking pattern is also called the printing process. Once the printing process (step S170) is completed, the process shown in the flowchart of Figure 6 is finished.

[0054] As described above, the control device 120 according to this embodiment determines that the printed pattern is dense because the line segment density De is greater than or equal to the density threshold De0, or because the line segment spacing parameter d is less than the spacing threshold d0, and decides to correct the printed pattern. On the other hand, the control device 120 determines that the printed pattern is sparse because the line segment density De is less than the density threshold De0 and the line segment spacing parameter d is greater than or equal to the spacing threshold d0, and decides not to correct the printed pattern. The control device 120 corrects the initial coordinates so that the line segments become thinner when at least one of the following conditions is met: the line segment density De is greater than or equal to the density threshold De0 (first condition), and the spacing parameter d is less than the spacing threshold d0 (second condition). Therefore, it is possible to prevent the printed pattern printed on the object to be printed 6 from becoming distorted or the line segments from becoming connected. In other words, when the printing pattern is dense, it is possible to prevent the visibility of the printing pattern printed on the object 6 from deteriorating.

[0055] According to the first embodiment, the following effects are achieved.

[0056] (1) The control device 120 corrects the printed pattern and generates a corrected printed pattern based on the degree of density of the set printed pattern and the material properties of the object to be printed 6. Specifically, the control device 120 calculates the degree of density of the set printed pattern. Based on the degree of density, the control device 120 determines whether the set printed pattern is sparse or dense. Based on the determination result of whether the printed pattern is sparse or dense, the control device 120 decides whether or not to correct the printed pattern. If the control device 120 decides not to correct the printed pattern, it controls the laser light emitted from the laser oscillator 1 based on the set printed pattern to draw the printed pattern on the object to be printed 6 without generating a corrected printed pattern. If the control device 120 decides to correct the printed pattern, it generates a corrected printed pattern based on the material properties of the object to be printed 6, and controls the laser light emitted from the laser oscillator 1 based on the corrected printed pattern to draw the corrected printed pattern on the object to be printed 6.

[0057] With this configuration, for example, if the printing pattern is dense and the material properties of the object to be printed 6 are such that they are highly susceptible to the influence of laser light (i.e., the thermal conductivity is greater than the standard thermal conductivity), the printing pattern can be corrected to reduce the number of printed areas, thereby preventing the width of the line segments printed on the object to be printed 6 from becoming too thick. In other words, the laser marker device 100 according to this embodiment can maintain consistent printing quality when printing patterns with varying degrees of density on various objects to be printed 6.

[0058] (2) The control device 120 corrects the initial coordinates that constitute the set printing pattern, and the printing pattern composed of the corrected coordinates is used as the corrected printing pattern. In this embodiment, if the printing pattern is dense, the initial coordinates are corrected so that the width of the line segments of the printing pattern becomes narrower. With this configuration, a highly visible marking pattern can be formed on the object to be printed 6 by correcting the coordinates.

[0059] (3) The control device 120 calculates the degree of density as the ratio of the area of ​​the line segments (line segment area) S to the area (region area) Sa enclosed by a rectangle formed by connecting the outermost edges of the line segments that constitute the set printing pattern. The control device 120 determines that the printing pattern is sparse if the line segment density De is less than the density threshold De0. The control device 120 determines that the printing pattern is dense if the line segment density De is equal to or greater than the density threshold De0. In this configuration, when the line segment density De is high, the printing pattern is corrected to make the line segments of the printing pattern thinner, thereby reducing the effect of heat generated by the laser light irradiated onto the printing pattern areas 161A and 161B, and preventing characters and other symbols in the printing pattern areas 161A and 161B from becoming distorted.

[0060] (4) The control device 120 calculates the degree of density as the interval parameter d, which represents the interval between line segments constituting the set printing pattern. The control device 120 determines that the printing pattern is sparse if the interval parameter d is greater than or equal to the interval threshold d0. The control device 120 determines that the printing pattern is dense if the interval parameter d is less than the interval threshold d0. In this embodiment, the interval parameter d is the minimum value of the interval between line segments. Therefore, in parts of the printing pattern areas 161A and 161B where the interval between line segments is locally narrow, it is possible to prevent the visibility of the printing pattern formed on the object to be printed from deteriorating due to line segments connecting with each other.

[0061] (5) The control device 120 stores the material properties of multiple objects to be printed 6. The laser marker device 100 includes a selection device (setting device 130) that selects one of the material properties of the multiple objects to be printed 6. The control device 120 generates a corrected printing pattern based on the material property (thermal conductivity) selected by the selection device (setting device 130). With this configuration, the user can easily select the material property of the object to be printed 6 using the input device 131 of the setting device 130.

[0062] <Modification 1 of the first embodiment> An example has been described in which steps S135 and S145 shown in Figure 6 are performed as a process to determine whether the printing pattern is sparse or dense, but the present invention is not limited to this. Either step S135 or step S145 may be omitted. If the process of step S135 is omitted, the processes of steps S120, S125, and S130 are also omitted. If the process of step S145 is omitted, the process of step S140 is also omitted.

[0063] <Modification 2 of the first embodiment> In the above embodiment, an example of correcting the printing pattern when it is determined that the printing pattern is dense was described. However, the present invention is not limited to this. The printing pattern may also be corrected when it is determined that the printing pattern is sparse. In this case, the control device 120 corrects the initial coordinates so that the line segments become thicker. In other words, if the printing pattern is sparse and the material properties of the object to be printed 6 are such that they are less affected by laser light (when the thermal conductivity is less than the reference thermal conductivity), the control device 120 corrects the printing pattern so that the number of printed areas increases. This prevents the width of the line segments printed on the object to be printed 6 from becoming too thin.

[0064] Furthermore, if the line segment density De is greater than or equal to the first density threshold De1, or if the interval parameter d is less than the first interval threshold d1, the initial coordinates may be corrected so that the line segments become thinner. Conversely, if the line segment density De is less than the second density threshold De2, or if the interval parameter d is greater than or equal to the second interval threshold d2, the initial coordinates may be corrected so that the line segments become thicker. Note that the first density threshold De1 is greater than the second density threshold De2, and the first interval threshold d1 is less than the second interval threshold d2.

[0065] <Modification 3 of the First Embodiment> As shown in Figure 11, the preview screen 170C may be configured to accept changes to the printing parameters. The print parameter setting image 173C on the preview screen 170C includes a setting value bar that shows the current setting value of the printing parameter. The setting value bar also shows the lower and upper limits of the printing parameter. If the input device 131 is a touch sensor, the setting value may be changed by directly touching this setting value bar. This makes it easy to adjust the visibility of the marking pattern formed on the object to be printed 6 by adjusting the printing parameters.

[0066] <Second Embodiment> Referring to Figures 12 to 15B, a laser marker apparatus 200 according to the second embodiment of the present invention will be described. Components identical or equivalent to those described in the first embodiment will be given the same reference numerals, and the differences will be explained primarily.

[0067] Figure 12 is a configuration diagram of the laser marker device 200 according to the second embodiment. As shown in Figure 12, the laser device 210 of the laser marker device 200 according to the second embodiment includes a laser oscillator 1, a beam diameter adjustment unit 203, a beam modulation unit 204, and a beam irradiation unit 5. The beam diameter adjustment unit 203 widens the laser light (laser beam) in the X-axis direction and the Y-axis direction.

[0068] The beam modulation unit 204 modulates the intensity distribution of the shaped laser beam in the X-axis and Y-axis directions. The beam modulation unit 204 can be constructed using elements such as a DMD (Digital Micromirror Device) or LCOS (Liquid Crystal On Silicon), which consist of multiple tiny mirrors (micromirrors) arranged in the X-axis and Y-axis directions. The micromirrors of the DMD can be in one of two states, ON or OFF, by driving electrodes located below the mirrors. In other words, the control method of the beam modulation unit 204 is a binary ON-OFF control method. When the micromirror is ON, the angle of the micromirror is controlled so that the laser beam reflected by the micromirror is irradiated onto the object to be printed 6. On the other hand, when the micromirror is OFF, the angle of the micromirror is controlled so that the laser beam reflected by the micromirror is not irradiated onto the object to be printed 6. In this way, by irradiating the DMD with a laser spot all at once and switching the ON-OFF state for each pixel, the laser beam can be irradiated onto the object to be printed on a pixel-by-pixel basis.

[0069] The object to be printed on, 6, is movable by a transport mechanism such as a belt conveyor. With the object to be printed on, 6 is irradiated with laser light from the beam irradiation unit 5 for a predetermined time, thereby forming a marking pattern on the object to be printed on, 6.

[0070] Figure 13 is a diagram similar to Figure 6, and is a flowchart showing an example of the print control process flow executed by the control device 220 according to the second embodiment. In the flowchart of Figure 13, the processes in steps S215, S220-S230, and S240 are executed instead of the processes in steps S115, S120-S130, and S140 of the flowchart in Figure 6. The processes that differ from the first embodiment will be explained in detail below, and the explanation of processes that are the same as in the first embodiment will be omitted.

[0071] In step S215, the initial coordinate setting unit 141 sets the initial coordinates of a marking pattern, such as a string of characters, based on the input signal from the input device 131. The initial coordinates set by the initial coordinate setting unit 141 correspond to information that identifies the micromirrors arranged in the X-axis and Y-axis directions (for example, an identification number assigned to each micromirror). The initial coordinates may also be a combination of the element array number in the X-axis direction and the element array number in the Y-axis direction.

[0072] In step S220, the coordinate correction unit 142 calculates the total number of pixels Na within the print pattern area based on the initial coordinates of the marking pattern. Specifically, as shown in Figures 14A and 14B, the coordinate correction unit 142 defines the print pattern area 261A, 261B as the area enclosed by a rectangle formed by connecting the outermost pixels of the pixels that display the line segments constituting the set print pattern, and calculates the total number of pixels (hereinafter also referred to as the area pixel count) Na within that area. The outermost pixels refer to the pixels in the X-axis direction and the outermost pixels in the Y-axis direction of the print pattern. The print pattern area 261A, 261B is formed by a straight line parallel to the X-axis direction that includes the upper edge of the uppermost pixel in the Y-axis direction, a straight line parallel to the X-axis direction that includes the lower edge of the lowermost pixel in the Y-axis direction, a straight line parallel to the Y-axis direction that includes the left edge of the leftmost pixel in the X-axis direction, and a straight line parallel to the Y-axis direction that includes the right edge of the rightmost pixel in the X-axis direction. Once the process in step S220 shown in Figure 13 is completed, the process proceeds to step S225.

[0073] In step S225, the coordinate correction unit 142 calculates the total number of pixels (hereinafter also referred to as the number of line segment pixels) N that display line segments (the blacked-out parts shown) within the print pattern areas 261A and 261B shown in Figures 14A and 14B. Once the processing in step S225 shown in Figure 13 is completed, the process proceeds to step S230.

[0074] In step S230, the coordinate correction unit 142 calculates the line segment density De by dividing the number of line segment pixels N calculated in step S225 by the number of region pixels Na calculated in step S220 (De = N / Na). In the second embodiment, the line segment density De corresponds to the proportion of pixels in the print pattern region that display line segments. The line segment density De is a first parameter that represents the degree of density of the print pattern. When the processing in step S230 is completed, the process proceeds to step S135.

[0075] In step S240, the coordinate correction unit 142 calculates the number of pixels between line segments constituting the print pattern, as shown in Figures 15A and 15B. The number of pixels between line segments includes the number of pixels between line segments in the X-axis direction and the number of pixels between line segments in the Y-axis direction. The coordinate correction unit 142 sets the minimum value of the calculated number of pixels as the interval parameter d, which represents the spacing between line segments constituting the set print pattern. The interval parameter d is a second parameter that represents the degree of density of the print pattern. Once the processing in step S240 shown in Figure 13 is completed, the process proceeds to step S145.

[0076] As described above, the laser marker device 200 according to the second embodiment includes a beam modulation unit 204 that switches the laser light emitted from the laser oscillator 1 ON and OFF on a pixel-by-pixel basis, and a control device 220 that controls the beam modulation unit 204. The control device 220 calculates the degree of sparseness as the line segment density De, which is the ratio of pixels that display line segments to pixels enclosed by a rectangle formed by connecting the outermost pixels of a plurality of pixels that display line segments constituting a set printing pattern. The control device 220 determines that the printing pattern is sparse if the line segment density De is less than the density threshold De0. The control device 220 determines that the printing pattern is dense if the line segment density De is greater than the density threshold De0. Furthermore, the control device 220 determines that the printing pattern is sparse if the interval parameter d is greater than or equal to the interval threshold d0. The control device 220 determines that the printing pattern is dense if the interval parameter d is less than the interval threshold d0. When the control device 220 determines that it is necessary to correct the printing pattern, it generates a corrected printing pattern based on the material properties of the object to be printed 6, and controls the beam modulation unit 204 based on the corrected printing pattern. In this configuration, when the line segment density De is higher than the density threshold De0, the printing pattern is corrected so that the line segments of the printing pattern become thinner as the thermal conductivity of the object to be printed 6 increases. This reduces the effect of heat generated by the laser light irradiated onto the printing pattern areas 161A and 161B, and prevents characters and other symbols in the printing pattern areas 161A and 161B from becoming distorted.

[0077] <Modified form of the second embodiment> The correction process for the printing pattern is not limited to the example described in the second embodiment above. Modifications of the correction process are described below.

[0078] <Modification 1 of the second embodiment> Figure 16 illustrates the correction process performed by the control device 220 according to Modification 1 of the second embodiment. As shown in Figure 16, the control device 220 draws line segments of the corrected printing pattern on the object to be printed 6 by controlling the beam modulation unit 204 so that the ON pixels (blacked-out areas) and OFF pixels (white areas) are arranged in a staggered pattern.

[0079] The correction process that arranges ON and OFF pixels in a staggered pattern (hereinafter referred to as the arrangement correction process) may be performed instead of the correction process that changes the line width (hereinafter referred to as the line width correction process) described above, or it may be performed after the line width correction process has been performed. The arrangement correction process is performed when the thermal conductivity of the object to be printed 6 is equal to or greater than a predetermined value, and is not performed when the thermal conductivity of the object to be printed 6 is less than a predetermined value.

[0080] By performing this alignment correction process, similar to the above embodiment, it is possible to prevent the print line width from becoming thicker and the visibility from deteriorating when the print pattern is dense.

[0081] <Modification 2 of the second embodiment> Figure 17 illustrates the correction process performed by the control device 220 according to Modification 2 of the second embodiment. The correction process according to this modification is performed when the printed pattern is a Chinese character. Similar to the second embodiment, the control device 220 determines that the printed pattern is dense and decides to correct the printed pattern. Furthermore, the control device 220 according to this modification divides the Chinese character as a printed pattern into multiple elements.

[0082] The elements of a kanji character refer to the elements that make up the character's form and can be broken down into left, right, top, bottom, inside, and outside parts. Examples of kanji elements include the left-hand radical (hen), the right-hand component (bō), the top part (kan), the bottom part (kyaku), the inside and outside components (kō), the outside part (kō), the top and left-hand components (sue), and the left and bottom parts (furo).

[0083] The control device 220 calculates the degree of density of each of the divided elements. The degree of density includes the line segment density De and the spacing parameter d, as in the example described above. The control device 220 determines the degree of correction for the elements according to the degree of density of the elements. For example, if the line segment density De of an element is greater than or equal to the first density threshold De1, the control device 220 arranges ON pixels in a staggered pattern across all pixels that make up the line segments of the initial printed pattern before correction. Also, if the line segment density De of an element is greater than or equal to the second density threshold De2 but less than the first density threshold De1, the control device 220 arranges ON pixels in a staggered pattern across some of the pixels that make up the line segments of the initial printed pattern before correction. In other words, when the line segment density De of an element is less than the first density threshold De1, the degree of correction is smaller than when the line segment density De is greater than or equal to the first density threshold De1.

[0084] With this modification, appropriate corrections are made to each element of the Chinese character, further improving the legibility of the printed marking pattern.

[0085] <Modification 3 of the second embodiment> In the second embodiment described above, an example of printing performed by binary ON-OFF control of the beam modulation unit 204 was explained, but the present invention is not limited thereto. The beam modulation unit 204 may be configured to rapidly switch between ON and OFF of pixels, adjust the time ratio of the ON state of the pixels, and enable gradation expression of line segments printed on the object 6. Furthermore, in the case of LCOS, it is not limited to binary control.

[0086] Figure 18 illustrates the correction process performed by the control device 220 according to Modification 3 of the second embodiment. Modification 3 of the second embodiment explains the differences from Modification 2 of the second embodiment described above. In this modification, if the thermal conductivity of the object to be printed 6 is equal to or greater than the first thermal conductivity threshold, the beam modulation unit 204 performs binary control of ON-OFF of the micromirrors. That is, in binary control, the micromirrors that are turned ON reflect the laser light toward the object to be printed 6 for the entire duration of the predetermined irradiation time ti, and the micromirrors that are turned OFF reflect the laser light toward the absorber for the entire duration of the irradiation time ti. On the other hand, if the thermal conductivity of the object to be printed 6 is less than the first thermal conductivity threshold, the micromirrors that were controlled OFF in the example of Figure 17 are controlled ON at a predetermined time ratio in the plurality of micromirrors constituting the line segment. In this case, the multiple micromirrors constituting the line segments of the printed pattern include micromirrors that reflect the laser light toward the object to be printed 6 for the entire duration of the irradiation time ti, and micromirrors that reflect the laser light toward the object to be printed 6 for a predetermined time (predetermined time ratio × irradiation time ti) within the entire duration of the irradiation time ti.

[0087] As described above, the control device 220 in this modified example adjusts the ON time ratio of a predetermined micromirror (pixel) among a plurality of micromirrors (pixels) that constitute the line segments of the printing pattern (initial printing pattern or printing pattern after line width correction) according to the thermal conductivity of the object to be printed 6. This further improves the visibility of the printed marking pattern.

[0088] <Modification 4 of the second embodiment> Similar to Modification 2 of the First Embodiment, if it is determined that the printing pattern is sparse, the micromirrors to be ON-controlled may be determined to make the line segments thicker. In other words, if the printing pattern is sparse and the material properties of the object to be printed 6 are such that they are less affected by laser light (when the thermal conductivity is less than the reference thermal conductivity), the control device 220 corrects the printing pattern to increase the number of printed areas. This prevents the width of the line segments printed on the object to be printed 6 from becoming too thin.

[0089] Furthermore, if the line segment density De is greater than or equal to the first density threshold De1, or if the interval parameter d is less than the first interval threshold d1, the initial coordinates may be corrected so that the line segments become thinner. If the line segment density De is less than the second density threshold De2, or if the interval parameter d is greater than or equal to the second interval threshold d2, the initial coordinates may be corrected so that the line segments become thicker.

[0090] The following modifications are also within the scope of the present invention, and it is possible to combine the configurations shown in the modifications with the configurations described in the embodiments described above, or to combine the configurations described in the different embodiments described above, or to combine the configurations described in the following different modifications.

[0091] <Example 1> In the above embodiment, an example was described in which the type of material of the object to be printed 6 is directly selected. However, the present invention is not limited thereto.

[0092] <Variation 1-1> The type of material may be indirectly selected by selecting information that can identify the type of material of the object to be printed 6. Figure 19 shows the material selection screen 360 for the object to be printed 6 displayed on the display device 132 based on the control signal of the control device according to this modified example 1-1. As shown in Figure 19, the selection screen 360 displays information from multiple manufacturers (food manufacturer names in the illustrated example). The selection screen 360 allows selection of one manufacturer from among multiple manufacturers. When one manufacturer is selected from among multiple manufacturers by the input device 131, information on the classification of multiple products handled by the selected manufacturer (food classifications in the illustrated example) is displayed. The selection screen 360 allows selection of one classification from among multiple product classifications.

[0093] When an input device 131 selects a product category from among multiple product categories, information on multiple products included in the selected category (product names in the illustrated example) is displayed. The selection screen 360 allows the selection of one product from among multiple products. When an product is selected from among multiple products by the input device 131, an image showing the appearance of the selected product, the material of the package which is the print target 6 for that product, and a confirmation button 376 are displayed. In this state, when the input device 131 performs a confirmation operation, the material of the print target 6 stored in association with the selected product and its material properties are selected.

[0094] With this configuration, even if the user does not know the type of material of the object to be printed 6, they can appropriately select the type of material of the object to be printed 6 if they know the manufacturer and product category of the object to be printed 6. In this modified example, an example was described in which the material properties of the object to be printed 6 are selected when the product of the object to be printed 6 is selected. However, when the product of the object to be printed 6 is selected, only the material of the object to be printed 6 may be displayed. In this case, the user confirms the material of the object to be printed 6 and then selects the type of material from the selection screen 160 shown in Figure 7.

[0095] <Variation 1-2> As shown in Figure 20, the control devices 120 and 220 may select a type of material from the material table 71 based on the input information when part or all of the name of the material of the object to be printed 6 is entered into the search window 377 displayed on the display screen of the display device 132.

[0096] <Modification 2> In a modified example of the second embodiment, the control device 220 divides a kanji character as a printing pattern into multiple elements and determines the degree of correction of the elements according to the degree of density of each of the divided elements. The method of determining the degree of correction according to the degree of density of each element may also be applied in the first embodiment. In this case, the control device 120 corrects the initial coordinates so that when the degree of density of the elements is high (dense), the width of the line segment becomes narrower compared to when it is low (sparse).

[0097] <Variation 3> The material properties table 143a is not limited to those described in the above embodiments. The material properties table 143a may be a data table that defines the relationship between thermal conductivity and the deviation from a reference width.

[0098] <Modification 4> In the above embodiment, an example was described in which the degree of correction is varied according to the thermal conductivity of the object to be printed 6. However, the present invention is not limited thereto. The material properties of the object to be printed 6 used to determine the degree of correction may be at least one of the following: thermal conductivity, laser light absorption rate, laser light transmittance, and laser light reflectance. In this case, the material property table 143a is a data table that defines the relationship between at least one of the thermal conductivity, absorption rate, transmittance, and reflectance and the correction parameter (printing line width, etc.) used for correction.

[0099] <Modification 5> In the first embodiment, an example was described in which the interval parameter d is the minimum value of the interval between line segments of the print pattern within the print pattern area. However, the interval parameter d can be any parameter that represents the interval between line segments. For example, the interval parameter d may be the average value of the interval between line segments of the print pattern within the print pattern area. Similarly, in the second embodiment, the interval parameter d may be the average value of the number of pixels between line segments within the print parameter area.

[0100] <Variation 6> In the above embodiment, an example was described in which the density of the printed pattern is determined by the line segment density De and the line segment spacing parameter d. However, the present invention is not limited thereto. For example, the density of the printed pattern may be determined by the combination of a character and the typeface of that character. In this case, data tables are stored in the control devices 120 and 220 in advance, which associate printed patterns consisting of combinations of characters and typefaces with information on whether the printed pattern is sparse or dense. According to this modified example, both the calculation process for the line segment density De and the calculation process for the spacing parameter d can be omitted.

[0101] Although embodiments of the present invention have been described above, these embodiments only represent a part of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments. [Explanation of Symbols]

[0102] 1...Laser oscillator, 2...Beam diameter adjustment unit, 3...First laser light scanning unit, 4...Second laser light scanning unit, 5...Beam irradiation unit, 6...Print target object, 71...Material table, 100...Laser marker device, 110...Laser device, 111...Galvanometer scanner, 120...Control device, 121...Processing device, 122...Non-volatile memory (storage device), 123...Volatile memory (storage device), 130...Setting device (selection device), 131...Input device (selection device), 132...Display device, 140...Print coordinate generation unit, 141...Initial coordinate setting unit, 142...Coordinate correction unit, 143...Characteristic storage unit, 143a...Material characteristic table, 144...Coordinate storage unit, 145...Print control unit, 146...Parameter setting unit, 1 47...Parameter storage unit, 148...Display control unit, 149...Pattern database, 160...Selection screen, 161A,161B...Print pattern area, 170,170C...Preview screen, 171A,171B...Preview image, 200...Laser marker device, 203...Beam diameter adjustment unit, 204...Beam modulation unit, 210...Laser device, 220...Control device, 261A,261B...Print pattern area, 360...Selection screen, d...Interval parameter, d0...Interval threshold, d1...First interval threshold, d2...Second interval threshold, De...Line segment density, De0...Density threshold, De1...First density threshold, De2...Second density threshold, N...Number of line segment pixels, Na...Number of area pixels, S...Line segment area, Sa...Area area

Claims

1. A laser marker device that prints by irradiating an object to be printed with laser light, The system comprises a laser oscillator that emits laser light, and a control device that controls the laser light emitted from the laser oscillator. The control device is The degree of density of the arrangement of line segments that make up the set printing pattern is calculated, Based on the degree of density, it is determined whether the set printing pattern is sparse or dense. If the printing pattern is determined to be dense, the printing line width is calculated based on the material properties of the object to be printed. If the calculated printing line width is greater than a predetermined reference width, a corrected printing pattern is generated by thinning the entire line segment constituting the printing pattern so that the width of the line segment constituting the printing pattern becomes narrower as the difference between the printing line width and the reference width increases. Based on the generated corrected printing pattern, the laser light emitted from the laser oscillator is controlled to draw the corrected printing pattern on the object to be printed. Laser marker device.

2. In the laser marker apparatus according to claim 1, If the control device determines that the printing pattern is sparse, it generates a corrected printing pattern by correcting the printing pattern based on the material properties of the object to be printed on, so that all the line segments constituting the printing pattern become thicker, and controls the laser light emitted from the laser oscillator based on the generated corrected printing pattern to draw the corrected printing pattern on the object to be printed on. Laser marker device.

3. In the laser marker apparatus according to claim 1, The control device corrects the initial coordinates that constitute the set print pattern, and the print pattern composed of the corrected coordinates becomes the corrected print pattern. Laser marker device.

4. In the laser marker apparatus according to claim 1, The control device is The degree of density is calculated as the ratio of the area occupied by the line segments to the area enclosed by the rectangle formed by connecting the outermost edges of the line segments that constitute the set printing pattern. If the line segment density is less than the density threshold, it is determined that the print pattern is sparse. If the line segment density is equal to or greater than the density threshold, it is determined that the printing pattern is dense. Laser marker device.

5. In the laser marker apparatus according to claim 1, The control device is The interval parameter representing the interval between line segments constituting the set printing pattern is calculated as the degree of density, If the interval parameter is greater than or equal to the interval threshold, it is determined that the print pattern is sparse. If the interval parameter is less than the interval threshold, it is determined that the print pattern is dense. Laser marker device.

6. In the laser marker apparatus according to claim 1, The laser oscillator is equipped with a beam modulation unit that switches the laser light emitted from the laser oscillator ON and OFF on a pixel-by-pixel basis. The control device is The degree of density is calculated as the ratio of pixels that display the line segments to pixels that display the line segments, within the rectangle formed by connecting the outermost pixels of the multiple pixels that display the line segments constituting the set print pattern. If the line segment density is greater than the density threshold, it is determined that the printing pattern is dense. If the printing pattern is determined to be too dense, a corrected printing pattern is generated by correcting the printing pattern so that the entire line segment constituting the printing pattern becomes thinner based on the material properties of the object to be printed on, and the beam modulation unit is controlled based on the generated corrected printing pattern. Laser marker device.

7. In the laser marker apparatus according to claim 6, The control device controls the beam modulation unit so that the ON pixels and OFF pixels are arranged in a staggered pattern, thereby drawing the line segments of the corrected printing pattern on the object to be printed. Laser marker device.

8. In the laser marker apparatus according to claim 6, The control device adjusts the ON time ratio of the plurality of pixels according to the material properties of the object to be printed. Laser marker device.

9. In the laser marker apparatus according to claim 1, The control device stores the material properties of multiple objects to be printed, The system includes a selection device that selects one of the material properties of the aforementioned multiple objects to be printed, The control device generates the corrected printing pattern based on the material properties selected by the selection device. Laser marker device.

10. In the laser marker apparatus according to claim 1, The aforementioned material properties are at least one of thermal conductivity, absorptivity, transmittance, and reflectance. Laser marker device.

Images