Processing method, processing device, and resin base material

Abstract

To provide a container 1 which is excellent in visibility of marking.SOLUTION: A processing method marks the surface of a container 1 as one example of a resin base material by irradiation with a processing laser beam 20, wherein the processing laser beam 20 has a beam profile so that a processing trace 111 is formed in the periphery of a projection 112 on the surface.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to a processing method, a processing device, and a resin substrate. [Background technology]

[0002] Patent Document 1 describes a substrate on which a highly visible pattern is formed, in which a predetermined shape constituting the pattern includes at least one of a predetermined recess or a predetermined protrusion, and at least one of the light transmittance and the light reflectance differs between a first region on the substrate in which the predetermined shape is formed and a second region on the substrate other than the first region. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-015739 A Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a resin substrate having excellent visibility of markings. [Means for solving the problem]

[0005] The processing method of the present invention is a processing method for marking the surface of a resin substrate by irradiating a laser, which has a region inside the laser beam irradiated to the resin substrate where the light intensity is below the processing threshold, and forms processing marks in a region surrounding the region below the processing threshold. Effect of the Invention

[0006] According to the present invention, a resin substrate having excellent visibility of markings can be provided. [Brief description of the drawings]

[0007] [Figure 1]1 is a diagram showing an example of the configuration of a container manufacturing device (optical marking device) and a laser irradiation unit according to an embodiment of the present invention. FIG. [Diagram 2] 1A and 1B are diagrams illustrating irradiation of laser light by a processed laser beam array. [Diagram 3] 2 is a block diagram showing an example of a hardware configuration of a control unit according to the embodiment; FIG. [Figure 4] 4 is a block diagram showing an example of a functional configuration of a control unit according to the embodiment; FIG. [Diagram 5] 4 is a flowchart illustrating an example of a manufacturing method according to the embodiment. [Figure 6] FIG. 4 is a diagram showing an example of pattern data. [Figure 7] FIG. 2 is a diagram illustrating an optical path according to an embodiment. [Figure 8] FIG. 4 is an explanatory diagram of a beam according to the embodiment. [Figure 9] 11 is a graph showing the relationship between irradiation intensity and processing amount according to the embodiment. [Figure 10] 11 is a photograph showing processing marks according to an embodiment. [Figure 11] FIG. 4 is a diagram showing the relationship between incident light and reflectance according to the embodiment. [Figure 12] 1 is a schematic diagram showing processing marks and the state of reflection of an incident beam. FIG. [Figure 13] FIG. 11 is an explanatory view showing details of a processed cross section according to the second embodiment. [Figure 14] 6 is a photograph showing processing marks for each area ratio of a protrusion portion according to an embodiment. [Figure 15] FIG. 13 is a schematic diagram showing the relationship between the dot pitch and the processing radius according to the embodiment; [Figure 16] FIG. 11 is an explanatory diagram showing the relationship between the pitch and the boundary wall height according to the second embodiment. [Figure 17] 11A and 11B are diagrams illustrating processing marks in a square arrangement according to the embodiment. [Figure 18] 10A to 10C are diagrams illustrating processing marks in a honeycomb arrangement according to an embodiment. [Figure 19] 13 is a graph showing the relationship between productivity ratio and quality evaluation results. [Figure 20]FIG. 2 is a diagram showing types of beam profile conversion elements. [Figure 21] 5A to 5C are schematic diagrams showing types of beam profiles according to the embodiment. [Figure 22] 5A to 5C are schematic diagrams showing intensity distributions near the image plane with and without wavefront aberration adjustment. [Diagram 23] FIG. 4 is a diagram showing the configuration of an aberration control mirror. [Figure 24] FIG. 11 is a diagram showing an optical adjustment flow. [Diagram 25] FIG. 13 is a diagram showing beam profiles with and without astigmatism adjustment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings, the same components are designated by the same reference numerals, and duplicated explanations may be omitted.

[0009] <Effects of container 1> Containers such as PET bottles are widely used due to their various advantages, such as preservation during distribution and sale of beverages. Containers distributed on the market are often affixed with labels indicating the product name, ingredients, expiration date, barcode, QR code (registered trademark), recycle mark, logo mark, etc. for management and sales promotion purposes. Labels can provide useful information to consumers. In addition, displaying designs to appeal to consumers on the label can help to demonstrate the individuality of the product and increase its competitiveness.

[0010] On the other hand, in recent years, the problem of marine plastic waste has come under scrutiny, and there has been a worldwide movement to eliminate environmental pollution caused by plastic waste. PET bottle containers are no exception to this, and measures to reduce plastic waste are being implemented from the perspective of environmentally friendly reduction.

[0011] Under these circumstances, there is an increasing demand for the closed-loop recycling of containers. Here, the closed-loop recycling of containers means that recycling companies convert used containers that have been separated and collected into flakes that can be used as the raw material for containers, and then remanufacture containers.

[0012] To facilitate this type of circular recycling, it is preferable to thoroughly separate and collect different materials such as container bodies, labels, and caps, etc., during the recycling process. To do so, consumers must separate the caps and labels from each container, and the task of removing the labels is particularly time-consuming for general consumers and local government resource recovery companies, as it is done manually. Therefore, the task of removing labels from containers is one of the constraints to thoroughly separate and collect them.

[0013] In response to this, technology to provide containers without labels is being considered. For example, a method of eliminating labels by printing a pattern displaying information on the container body using an inkjet method is being considered.

[0014] However, if the ink applied by printing remains in the bottle during the recycling process after collection, impurities increase, which may be undesirable. Also, if the ink is removed from the container body during the recycling process to reduce impurities, the management information will be lost, which may be undesirable.

[0015] In contrast, the present embodiment provides a container 1 in which a marking is formed on the surface by irradiating it with a laser.

[0016] <Configuration example of manufacturing apparatus 100> FIG. 1(a) is a diagram showing an example of the configuration of a manufacturing apparatus (optical marking apparatus) 100. The manufacturing apparatus (optical marking apparatus) 100 is an apparatus for integrally forming a first pattern composed of an aggregate of second patterns on at least one of the surface or interior of the substrate 1 by changing the properties of the substrate constituting the container. Here, the properties of the substrate refer to the nature or state of the substrate. The manufacturing apparatus 100 is an example of a processing apparatus.

[0017] As shown in FIG. 1(a), the manufacturing apparatus (optical marking apparatus) 100 includes a laser irradiation unit 2, a rotation mechanism 3 for recovering the workpiece, a holding unit 31, a moving mechanism 4, a dust collecting unit 5, and a control unit 6. The manufacturing apparatus 100 holds the container 1, which is a cylindrical container, rotatably around the cylindrical axis 10 of the container 1 via the holding unit 31. Then, the laser irradiation unit 2 irradiates the container 1 with laser light to change the properties of the base material constituting the container 1, thereby forming a first pattern composed of an assembly of second patterns on the surface of the container 1. Here, the cylindrical axis 10 is an example of a "predetermined axis." In the following, in order to simplify the explanation, the first pattern composed of an assembly of second patterns may be appropriately referred to as the first pattern.

[0018] A laser irradiation unit 2 as an example of an irradiation unit scans a laser light emitted from a laser light source in the Y direction in Fig. 1(a) and irradiates a processed laser beam 20 as an example of a laser beam toward the container 1 arranged in the positive Z direction. The laser irradiation unit 2 will be described in detail with reference to Fig. 1(b).

[0019] The rotation mechanism 3, which is an example of a rotating part, holds the container 1 via a holding part 31. The holding part 31 is a coupling member connected to a motor shaft of a motor (not shown) serving as a drive part of the rotation mechanism 3, and holds the container 1 by inserting one end into the mouth of the container 1. The rotation of the motor shaft rotates the holding part 31, and thereby rotates the container 1 held by the holding part 31 around the cylindrical axis 10.

[0020] The moving mechanism 4, which is an example of a moving part, is a linear stage equipped with a table, and the rotation mechanism 3 is placed on the table of the moving mechanism 4. The moving mechanism 4 moves the table back and forth in the Y direction, thereby moving the rotation mechanism 3, the holding part 31, and the container 1 together back and forth in the Y direction.

[0021] The dust collection unit 5 is an air suction device arranged near the portion of the container 1 that is irradiated with the processing laser beam 20. By collecting the plume and dust generated when forming the first pattern by irradiating the processing laser beam 20 with air, the manufacturing apparatus 100, the container 1, and the surrounding area are prevented from being soiled by the plume and dust.

[0022] The control unit 6 is electrically connected to each of the laser light source 21, the scanning unit 23, the rotation mechanism 3, the moving mechanism 4 and the dust collection unit 5 via cables or the like, and controls the operation of each by outputting a control signal.

[0023] In the manufacturing apparatus 100, while rotating the container 1 by the rotation mechanism 3 under the control of the control unit 6, the laser irradiation unit 2 irradiates the container 1 with a processing laser beam 20 scanned in the Y direction. Then, a first pattern is two-dimensionally formed on at least one of the front and back surfaces or the inside of the base material in the container 1.

[0024] Here, the scanning area in the Y direction of the processing laser beam 20 by the laser irradiation unit 2 may be limited in range. Therefore, when forming the first pattern in a range wider than the scanning area, the manufacturing apparatus 100 shifts the irradiation position of the processing laser beam 20 on the container 1 in the Y direction by moving the container 1 in the Y direction with the movement mechanism 4. Thereafter, while rotating the container 1 again with the rotation mechanism 3, the laser irradiation unit 2 scans the processing laser beam 20 in the Y direction to form the first pattern on at least one of the surface or the inside of the base material in the container 1. This allows the first pattern to be formed in a wider area of ​​the container 1 (any area from the mouth to the bottom of the bottle).

[0025] <Configuration example of laser irradiation unit 2> Fig. 1(b) is a diagram showing an example of the configuration of the laser irradiation unit 2. As shown in Fig. 1(b), the laser irradiation unit 2 includes a laser light source 21, a beam expander 22, a scanning unit 23, a scanning lens 24, and a synchronization detection unit 25.

[0026] The laser light source 21 is, for example, a pulsed laser that emits laser light. The laser light source 21 emits laser light with an output (light intensity) suitable for changing the properties of at least one of the surface and the inside of the base material in the container 1 irradiated with the laser light.

[0027] The laser light source 21 is capable of controlling the on / off of laser light emission, the emission frequency, the light intensity, and the like.

[0028] Transparent resin is transparent to visible light and does not absorb it, but absorbs a large proportion of infrared and ultraviolet light. In the infrared region, a carbon dioxide gas laser with a wavelength of 10 um is suitable.

[0029] In the short wavelength region, the shorter the wavelength, the greater the absorption by transparent resin tends to be. In the UV-A (ultraviolet) region, which is in the wavelength range of 315 to 400 nm, both absorption and transmission occur. In the UV-C (deep ultraviolet) region, which is in the wavelength range of 100 to 280 nm, almost no transmission occurs and the light is absorbed.

[0030] Specifically, when the transmittance of a PET bottle was measured, it was 74% for 355 nm, which corresponds to the third harmonic of YAG, and almost 0% for 266 nm, which corresponds to the fourth harmonic of YAG. The absorption of 266 nm is about four times higher. In other words, there is a possibility that productivity will be improved by four times.

[0031] The laser light source 21 may be composed of one laser light source or may be composed of multiple laser light sources. When multiple laser light sources are used, the on / off control, emission frequency control, light intensity control, etc. may be performed independently for each laser light source, or may be shared.

[0032] The diameter of the parallel laser light emitted from the laser light source 21 is expanded by the beam expander 22 and enters the scanning unit 23 .

[0033] The scanning unit 23 is an example of a deflection means for deflecting a laser beam, and includes a scanning mirror that changes the reflection angle by a driving unit such as a motor. By changing the reflection angle of the scanning mirror, the incident laser light is scanned in the Y direction. A galvanometer mirror, a polygon mirror, a MEMS (Micro Electro Mechanical System) mirror, or the like can be used as this scanning mirror.

[0034] In the embodiment, the scanning unit 23 performs one-dimensional scanning with the laser light in the Y direction, but the present invention is not limited to this. The scanning unit 23 may perform two-dimensional scanning with the laser light in the XY directions using a scanning mirror that changes the reflection angle in two orthogonal directions.

[0035] However, when irradiating the surface of the cylindrical container 1 with laser light, two-dimensional scanning in the XY directions causes the beam spot diameter on the surface of the container 1 to change in response to scanning in the X direction, so one-dimensional scanning is preferable in such cases.

[0036] The laser light scanned by the scanning unit 23 is irradiated as a processing laser beam 20 onto at least one of the surface and the interior of the base material in the container 1 .

[0037] The scanning lens 24 is an example of a condenser lens and a scanning lens means, and is an fθ lens that keeps the scanning speed of the processing laser beam 20 scanned by the scanning unit 23 constant and converges the processing laser beam 20 to a predetermined position on at least one of the surface and the interior of the base material in the container 1. It is preferable that the scanning lens 24 and the container 1 are arranged so that the beam spot diameter of the processing laser beam 20 is minimized in the region in the container 1 where the properties of the base material are changed. Note that the scanning lens 24 may be configured by a combination of multiple lenses.

[0038] The synchronization detection unit 25 outputs a synchronization detection signal used to synchronize the scanning of the processing laser beam 20 and the rotation of the container 1 by the rotation mechanism 3. The synchronization detection unit 25 includes a photodiode that outputs an electrical signal according to the intensity of the received light, and outputs the electrical signal from the photodiode to the control unit 6 as a synchronization detection signal.

[0039] FIG. 1(b) shows an example of scanning a processing laser beam, but it is also possible to provide a number of processing laser beams within the range of the printing width to form a processing laser beam array, and rotate the container 1 to scan the container 1 with a number of laser beams in one direction.

[0040] FIG. 2 shows an example of this, showing a processing laser beam array 20a consisting of a plurality of parallel laser beams in a container 1. As shown in FIG.

[0041] <Example of hardware configuration of control unit 6> 3 is a block diagram showing an example of a hardware configuration of the control unit 6. The control unit 6 is constructed using a computer.

[0042] 3, the control unit 6 includes a CPU (Central Processing Unit) 501, a ROM (Read Only Memory) 502, a RAM (Random Access Memory) 503, a HD (Hard Disk) 504, a HDD (Hard Disk Drive) controller 505, and a display 506. The control unit 6 also includes an external device connection I / F (Interface) 508, a network I / F 509, a data bus 510, a keyboard 511, a pointing device 512, a DVD-RW (Digital Versatile Disk Rewritable) drive 514, and a media I / F 516.

[0043] Of these, the CPU 501 is a processor that controls the overall operation of the control unit 6. The ROM 502 is a memory that stores programs used to drive the CPU 501, such as an IPL (Initial Program Loader).

[0044] The RAM 503 is a memory used as a work area for the CPU 501. The HD 504 is a memory for storing various data such as programs. Digital data related to various fonts (Gothic, Ming, Arial, Times New Roman, etc.) expressing character information that can be expressed by various numbers such as Arabic numerals, Roman numerals, and Chinese numerals, Katakana, Hiragana, 26 uppercase and lowercase letters of the alphabet (abcd, ABCD), Chinese characters, Hangul characters, symbols, and characters having complex structures, which are formed integrally with the container as a first pattern, is stored in this HD 504. The HDD controller 505 controls the reading and writing of various data from and to the HD 504 under the control of the CPU 501.

[0045] The display 506 displays various information such as a cursor, a menu, a window, characters, or an image. The external device connection I / F 508 is an interface for connecting various external devices. In this case, the external devices are the laser light source 21, the scanning unit 23, the synchronization detection unit 25, the rotation mechanism 3, the movement mechanism 4, and the dust collection unit 5. However, other devices such as a USB (Universal Serial Bus) memory and a printer can also be connected.

[0046] The network I / F 509 is an interface for data communication using a communication network means. It may be an interface for a communication network such as a wireless LAN such as WiFi or a wired LAN using an Ethernet cable. Using this network I / F 509 or the communication network means, material data of the workpiece such as a container, processing parameter information according to the material such as the material of the container, font data of various characters and symbols formed integrally with the container, etc. can be input from the outside to the control unit 6. The bus line 510 is an address bus, a data bus, etc. for electrically connecting each component such as the CPU 501 shown in FIG. 3.

[0047] The keyboard 511 is a type of input means having a plurality of keys for inputting characters, numbers, various instructions, etc. The pointing device 512 is a type of input means for selecting and executing various instructions, selecting a processing target, moving a cursor, etc.

[0048] A DVD-RW drive 514 controls reading and writing of various data from and to a DVD-RW 513 as an example of a removable recording medium. Note that the medium is not limited to a DVD-RW, and may be a DVD-R or the like. A media I / F 516 controls reading and writing (storing) of data from and to a recording medium 515 such as a flash memory.

[0049] <Example of functional configuration of control unit 6> FIG. 4 is a block diagram showing an example of a functional configuration of the control unit 6. As shown in FIG.

[0050] 4, the control unit 6 includes a first pattern data input unit 61, a second pattern parameter designation unit 62, a storage unit 63, a processing data generation unit 64, a laser irradiation control unit 65, a laser scanning control unit 66, a container rotation control unit 67, a container movement control unit 68, and a dust collection control unit 69. The material data of the workpiece stores processing parameter information corresponding to the material, such as resin.

[0051] Among these, the functions of the first pattern data input unit 61, the second pattern parameter designation unit 62, the processing data generation unit 64, the laser irradiation control unit 65, the laser scanning control unit 66, the container rotation control unit 67, the container movement control unit 68, and the dust collection control unit 69 are all realized by the CPU 501 in Fig. 3 executing a predetermined program and outputting a control signal via the external device connection I / F 508. However, an electronic circuit or an electric circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-Programmable Gate Array) may be added to the hardware configuration of the control unit 6 to realize some or all of the functions of each of the above components by the electronic circuit or the electric circuit. The function of the storage unit 63 is realized by the HD 504, etc.

[0052] The first pattern data input unit 61 inputs pattern data of a first pattern to be formed on at least one of the surface or the inside of the base material in the container 1 from an external device such as a PC (Personal Computer) or a scanner. The pattern data of the first pattern is electronic data including information indicating a pattern such as a code such as a barcode or a QR code, a character, a figure, a photograph, etc., and information indicating the type of the first pattern.

[0053] However, the pattern data is not limited to data input from an external device. A user of the manufacturing apparatus 100 may input the pattern data of the first pattern generated using the keyboard 511 or the pointing device 512 of the control unit 6.

[0054] The first pattern data input unit 61 outputs the input pattern data of the first pattern to the processing data generation unit 64 and the second pattern parameter designation unit 62, respectively.

[0055] The second pattern parameter designation unit 62 designates processing parameters for forming the second pattern. As described above, the second pattern is a line or a dot having a length or width smaller than that of the first pattern, or a length and a width smaller than that of the first pattern, and acts to increase the contrast of the first pattern and improve visibility.

[0056] The processing parameters of the second pattern are information that specifies the type, length, thickness, processing depth of the lines as the second pattern, or the spacing or arrangement, density, etc. between adjacent lines in a collection of lines, or the type, size, processing depth of the dots as the second pattern, or the spacing or arrangement, density, etc. between adjacent dots in a collection of dots.

[0057] The line type is information indicating a straight line, a curve, etc. The point type is information indicating a shape of a point, such as a circle, an ellipse, a rectangle, a diamond, etc. In the collection of second patterns, the second patterns may be configured to have periodicity or may be configured to be non-periodic. However, configuring the second patterns to have periodicity is preferable because it simplifies the specification of parameters.

[0058] Processing parameters for the second pattern suitable for improving visibility corresponding to the type of the first pattern, such as characters, codes, figures, or photographs, are determined in advance through experiments and simulations. The storage unit 63 stores a table showing the correspondence between such types of first patterns and processing parameters. The outer frame of the first pattern may or may not be processed. Processing makes the outline clearer. Not processing improves drawing efficiency.

[0059] The second pattern parameter designation unit 62 can refer to the storage unit 63 based on information indicating the type of the first pattern input from the first pattern data input unit 61, and acquire and designate processing parameters for the second pattern.

[0060] However, the method of designation by the second pattern parameter designation unit 62 is not limited to the above. The second pattern parameter designation unit 62 may receive a user instruction via the keyboard 511 or the pointing device 512 of the control unit 6, and refer to the storage unit 63 based on the instruction to acquire the processing parameters of the second pattern.

[0061] Furthermore, the second pattern parameter designation unit 62 may acquire processing parameters of the second pattern generated by a user of the manufacturing apparatus 100 using the keyboard 511 or the pointing device 512 of the control unit 6.

[0062] The processing data generating unit 64 generates processing data for forming the first pattern constituted by a collection of the second patterns, based on the pattern data of the first patterns and the processing parameters of the second patterns.

[0063] The processing data includes rotation condition data for the rotation mechanism 3 to rotate the container 1, scanning condition data for the laser irradiation unit 2 to scan the processing laser beam 20, and irradiation condition data for the laser irradiation unit 2 to irradiate the processing laser beam 20 in synchronization with the rotation of the container 1. The processing data also includes movement condition data for the movement mechanism 4 to move the container 1 in the Y direction, and dust collection condition data for the dust collection unit 5 to perform a dust collection operation.

[0064] The processing data generating unit 64 outputs the generated processing data to each of the laser irradiation control unit 65, the laser scanning control unit 66, the container rotation control unit 67, the container movement control unit 68, and the dust collection control unit 69.

[0065] The laser irradiation control unit 65 includes a light intensity control unit 651 and a pulse control unit 652, and controls the irradiation of the processing laser beam 20 onto the container 1 by the laser light source 21 based on the irradiation condition data. The laser irradiation control unit 65 also controls the timing of irradiation of the processing laser beam 20 onto the container 1 in synchronization with the rotation of the container 1 by the rotation mechanism 3 based on a synchronization detection signal from the synchronization detection unit 25. Note that, since the known technology disclosed in JP 2008-073894 A and the like can be applied to the irradiation timing control using the synchronization detection signal, a detailed description thereof will be omitted here.

[0066] When the laser light source 21 is composed of a plurality of laser light sources, the laser irradiation control unit 65 performs the above control independently for each of the plurality of laser light sources.

[0067] The light intensity control unit 651 controls the light intensity of the processing laser beam 20 , and the pulse control unit 652 controls the pulse width and irradiation timing of the processing laser beam 20 .

[0068] The laser scanning control unit 66 controls the scanning of the processing laser beam 20 by the scanning unit 23 based on the scanning condition data. Specifically, it controls the on / off of driving the scanning mirror, controls the driving frequency, and the like.

[0069] Based on the rotation condition data, the container rotation control unit 67 controls the on / off of the rotation drive of the container 1 by the rotation mechanism 3, the rotation angle, the rotation direction, the rotation speed, etc. Note that the container rotation control unit 67 may continuously rotate the container 1 in a predetermined rotation direction, or may rotate (swing) the container 1 back and forth within a predetermined angle range such as ±90 degrees while switching the rotation direction.

[0070] The container movement control unit 68 controls the on / off, movement direction, movement amount, movement speed, etc. of the movement drive of the container 1 by the movement mechanism 4 based on the movement condition data.

[0071] The dust collection control unit 69 controls the on / off of dust collection by the dust collection unit 5, the amount of air to be sucked or the flow rate, etc., based on the dust collection condition data. Note that a mechanical unit for moving the dust collection unit 5 may be provided, and the movement of the dust collection unit 5 by the mechanical unit may be controlled so that the dust collection unit 5 is located near the position where the processing laser beam 20 is irradiated.

[0072] <Example of manufacturing method using manufacturing apparatus 100> FIG. 5 is a flow chart showing a manufacturing method using the manufacturing apparatus 100 as an example of the processing method according to the present invention.

[0073] First, in step S51, the first pattern data input unit 61 inputs pattern data of the first pattern from an external device such as a PC, a scanner, etc. The first pattern data input unit 61 outputs the input pattern data of the first pattern to each of the processing data generation unit 64 and the second pattern parameter designation unit 62.

[0074] Next, in step S52, the second pattern parameter designation unit 62 designates processing parameters for forming the second pattern. The second pattern parameter designation unit 62 acquires and designates processing parameters for the second pattern by referring to the storage unit 63 based on the information indicating the type of the first pattern input from the first pattern data input unit 61.

[0075] The order of the operations in steps S51 and S52 may be changed as appropriate, and these steps may be executed in parallel.

[0076] Next, in step S53, the processing data generating unit 64 generates processing data for forming a first pattern constituted by an aggregate of second patterns based on the pattern data of the first pattern and the processing parameters of the second pattern, and outputs the generated processing data to each of the laser irradiation control unit 65, the laser scanning control unit 66, the container rotation control unit 67, the container movement control unit 68, and the dust collection control unit 69.

[0077] Next, in step S54, the laser scanning control unit 66 causes the scanning unit 23 to start scanning in the Y direction with the processing laser beam 20 based on the scanning condition data. In the embodiment, in response to the start of scanning, the scanning unit 23 continues scanning in the Y direction with the processing laser beam 20 until an instruction to stop the scanning is given.

[0078] Next, in step S55, the container rotation control unit 67 causes the rotation mechanism 3 to start rotating the container 1 based on the rotation condition data. In this embodiment, in response to the start of the rotation, the rotation mechanism 3 continues to rotate the container 1 until an instruction to stop the rotation is given.

[0079] Next, in step S56, the container movement control unit 68 causes the movement mechanism 4 to move the container 1 to an initial position in the Y direction based on the movement condition data so that the processing laser beam 20 is irradiated to a predetermined position of the container 1. After the container 1 has been moved to the initial position, the container movement control unit 68 stops the movement mechanism 4.

[0080] The order of the operations from step S54 to step S56 may be changed as appropriate, and these steps may be executed in parallel.

[0081] Subsequently, in step S57, the laser irradiation control unit 65 starts controlling the irradiation of the processing laser beam 20 onto the container 1.

[0082] Specifically, the laser irradiation unit 2 scans one line along the Y direction and irradiates the container 1 with the processing laser beam 20. Then, the rotation mechanism 3 rotates a predetermined angle around the cylindrical axis 10 of the container 1. After rotating by the predetermined angle, the laser irradiation unit 2 scans the next line and irradiates the container 1 with the processing laser beam 20. Then, the rotation mechanism 3 rotates a predetermined angle around the cylindrical axis 10 of the container 1. By repeating such operations, a first pattern is sequentially formed on at least one of the surface or interior of the base material in the container 1.

[0083] Subsequently, in step S58, the laser irradiation control unit 65 determines whether or not the formation of the first pattern has been completed on a predetermined area of ​​the container 1 in the Y direction.

[0084] If it is determined in step S58 that the process has not ended (No in step S58), the process from step S56 onwards is repeated again.

[0085] On the other hand, if it is determined in step S58 that the process has ended (Yes in step S58), then in step S59, the rotation mechanism 3 stops the rotational driving of the container 1 in response to a stop instruction from the container rotation control unit 67.

[0086] Subsequently, in step S60, the scanning unit 23 stops scanning with the processing laser beam 20 in response to a stop instruction from the laser scan control unit 66. The laser light source 21 stops irradiating the processing laser beam 20 in response to a stop instruction from the laser irradiation control unit 65.

[0087] The order of the operations in steps S59 and S60 may be changed as appropriate, and these steps may be performed in parallel.

[0088] In this manner, the manufacturing apparatus 100 can form a first pattern composed of an assembly of second patterns on at least one of the surface and the interior of the base material in the container 1.

[0089] <Examples of various data> Next, an example of various data used in the manufacture of the container 1 will be described.

[0090] (Pattern data example) FIG. 6 is a diagram showing an example of the pattern data of the first pattern input by the first pattern data input unit 61. As shown in FIG.

[0091] 6, the pattern data 611 includes character data 612, "LABELLESS," and the character data 612 is to be formed on the container 1 as a first pattern. A set of multiple lines constituting the five characters of "LABELLESS" corresponds to data for the first pattern. Data in the pattern data 611 other than the character data 612 is not to be formed on the container 1.

[0092] The pattern data 611 is provided as an image file such as a bitmap file, for example. The header information of the image file that provides the pattern data 611 includes information indicating the type of the first pattern. In this example, the type of the first pattern is "character."

[0093] The first pattern data input unit 61 outputs pattern data 611 including information indicating “characters” to each of the second pattern parameter designation unit 62 and the processed data generation unit 64.

[0094] The base material of the container 1 described above may be polyvinyl alcohol (PVA), polybutylene adipate / terephthalate (PBAT), polyethylene terephthalate succinate, polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polyvinyl chloride (PVC), polystyrene (PS), polyurethane, epoxy, biopolybutylene succinate (PBS), polylactic acid blend (PBAT), starch blend polyester resin, polybutylene terephthalate succinate, polylactic acid (PLA), polyhydroxybutyrate / hydroxyhexanoate (PHBH), polyhydroxyalkanoic acid (PHA), bioPET30, biopolyamide (PA) 610, 410, 510, bioPA1012, 10T, bioPA11T, MXD10, biopolycarbonate, Bio-polyurethane, bio-PE, bio-PET100, bio-PA11, bio-PA1010, etc. can be used.

[0095] Here, a Gaussian beam is generally used as the processing laser beam 20 described above. However, with a Gaussian beam, the energy is excessively concentrated at the center of the optical axis, resulting in a narrow processing area and a problem in productivity.

[0096] Furthermore, when attempting to form fine dots so as to increase the amount of diffusely reflected light in order to improve visibility, there is a problem that productivity decreases.

[0097] In view of the above problems, the present embodiment aims to provide a container 1 that has excellent visibility of surface markings while increasing productivity by enabling a larger area to be processed with the same irradiation energy as a Gaussian beam.

[0098] FIG. 7 is a diagram showing an optical path according to the embodiment, and shows details of the laser irradiation unit 2 described in FIG. 1(b).

[0099] The laser irradiation unit 2 shown in FIG. 7 includes five reflecting mirrors M1 to M5, but may include ten or more mirrors.

[0100] The laser irradiation section 2 includes a wavefront aberration control unit 30 and a beam profile conversion element 40 in this order downstream of the beam expander 22 along the optical path, and a damper 50 downstream of the movement mechanism 4.

[0101] The wavefront aberration control unit 30 controls the wavefront 20A of the incident light to the wavefront 20B of the outgoing light, thereby reducing the problem of changes in the light intensity distribution near the image plane caused by the inherent aberrations of the laser oscillator and optical components.

[0102] FIG. 8 is an explanatory diagram of a beam according to the embodiment.

[0103] Fig. 8(a) is a diagram showing the cross-sectional shape of the beam profile according to the embodiment, and Fig. 8(b) is a diagram showing the light intensity S1 and beam diameter D1 of the non-Gaussian beam according to the embodiment and the light intensity S0 and beam diameter D0 of the Gaussian beam according to the comparative example, where the vertical axis represents the relative light intensity under the same energy condition.

[0104] FIG. 8(c) is a schematic diagram showing a processed cross section according to the embodiment, in which a protrusion 112 is formed at the center of a processed mark 111 on the surface of the container 1.

[0105] As shown in Figures 8(a) and (b), the beam profile of the embodiment is set so that the central light intensity is less than the processing threshold value t, and as shown in Figure 8(c), a protrusion 112 is formed corresponding to the region in the beam profile where the light intensity is less than the processing threshold value.

[0106] That is, the protrusion 112 is a region that remains unprocessed because the light intensity is less than the processing threshold value t.

[0107] The presence of such protrusions 112 makes it possible to realize a small and steep recess shape, and when viewed in cross section, the diameter of the recess is halved if the depth is constant, so the aspect ratio of the recess is simply slightly more than doubled. FIG. 9 is a graph showing the relationship between the irradiation intensity (fluence) and the amount of processing of the processed area or volume according to the embodiment.

[0108] If the fluence is small, no processing occurs. When the fluence exceeds a certain size (threshold), the energy is exchanged on the material surface for electronic, thermal, photochemical and mechanical energy, and processing begins. This threshold is defined as the processing threshold. The processing threshold depends on the material, but for PET bottles it is 0.2 to 0.8 J / cm2.

[0109] For this reason, the area below the processing threshold is not processed, and the surrounding area is processed and recessed, resulting in a protrusion in the center of the irradiated area.

[0110] In addition, as shown in Fig. 8(b), the outer diameter of the beam can be increased for the same energy. The Gaussian beam has too much energy concentrated in the center, resulting in large energy loss, whereas the beam of the embodiment is advantageous for large area processing and can improve productivity.

[0111] Fig. 10 is a photograph showing the processing marks according to the embodiment. Fig. 10 is a photograph taken by microscope showing the processing result of an isolated dot shape, in which a picosecond laser with a wavelength of 355 nm was used to irradiate the target object with a circular ring with an aspect ratio of 5% or less with an energy of 35 uJ. As a result of processing, the diameter of the processing mark 111 was 70 um, and the central protrusion 112 was 5 um or more and the area was 3% of the entire processing mark 111.

[0112] The protrusions 112 are observed under epi-illumination with a microscope with approximately the same brightness as the non-processed regions 113. Since the processed marks 111 are recessed relative to the non-processed regions 113, the protrusions 112 appear as convex relative to the processed marks 111.

[0113] Fig. 11 is a diagram showing the relationship between incident light and reflectance according to the embodiment. Fig. 11 shows the theoretical relationship between the angle of incidence and reflectance, and shows the reflectance of P polarized light, S polarized light, and R (random) polarized light calculated with a refractive index of n = 1.65, assuming a PET bottle. It can be seen that the reflected component is large when the incident angle is as large as possible, i.e., when the light is incident at a shallow angle. To achieve this, it is advisable to create an uneven structure that is as fine as possible.

[0114] FIG. 12 is a schematic diagram showing the processing marks and the state of reflection of the incident beam.

[0115] FIG. 12(a) is a schematic diagram showing the processing mark caused by a Gaussian beam in a comparative example and the state of reflection of the incident beam. Since the processing area indicated by the size of the processing mark 111 is wide, the incident angle with respect to the surface of the processing area is small, i.e., the incident beam is close to the perpendicular side with respect to the surface, so that the refracted light is large and the reflected light is relatively small.

[0116] FIG. 12(b) is a schematic diagram showing the processing mark and the reflection state of the incident beam in Example 1 of the embodiment. The processing area is divided by the protrusion 112 in the center of the processing mark 111, and the recess related to the processing mark 111 has a steep shape. Therefore, the incident angle with respect to the surface of the processing area is large, i.e., the incident beam is nearly parallel to the surface, and therefore the reflected light is large.

[0117] Furthermore, since the protrusion 112 is positioned at the center of the processing mark 111, diffuse reflected light is easily obtained, improving visibility.

[0118] FIG. 12(c) is a schematic diagram showing the state of the processing mark and the reflection of the incident beam in Example 2 of the embodiment, in which the height of the protrusion 112 in the center of the processing mark 111 is higher than the height of the non-processed area 113 surrounding the processing mark 111, which has the same effect as making the processing mark 111 deeper, and the reflected light is further increased.

[0119] Furthermore, by increasing the height of the protrusion 112 located at the center of the processing mark 111, it becomes easier to obtain diffuse reflected light, and visibility is further improved.

[0120] 12(c), by irradiating the periphery, the molten material moves toward the center, pushing up the unprocessed area in the center, and the protrusion 112 can be made higher than the height of the unprocessed area 113. In actual measurements, the height of the processing mark 111 from the bottom surface of the protrusion 112 is 2 to 6 um, and if the protrusion 112 is made thinner, a height of 10 um can be achieved.

[0121] FIG. 13 is an explanatory diagram showing details of the processed cross section according to the second embodiment shown in FIG. 12(c).

[0122] Fig. 13(a) shows the processed surface, and Pw is the width of the protrusion 112. Fig. 13(b) shows the processed cross section corresponding to Fig. 13(a), and Hp is the height of the protrusion 112 from the bottom of the processed mark 111, Dp is the depth of the bottom of the processed mark 111 relative to the non-processed region 113, and Hb is the height of the boundary between the outer periphery of the processed mark 111 and the non-processed region 113 from the bottom of the processed mark 111. Dp is usually 2 to 8 um, and 3 to 6 um is said to be preferable.

[0123] 13(c) is a diagram in which the processed cross section when Pw is Pw1 and the processed cross section when Pw is Pw2 are overlapped. As shown in FIG. 13(c), the applicant has found that Hp can be increased by narrowing Pw.

[0124] Specifically, the experimental results were as follows: when Pw=25um, Hp=3um, when Pw=15um, Hp=5um, when Pw=12um, Hp=8um, when Pw=10um, Hp=10um, and when Pw=9um or less, Hp=10um or more.

[0125] As mentioned above, this is thought to be because the melted material caused by irradiating the periphery of the protrusion 112 moves toward the center and pushes up the central unprocessed area, and the amount of pushing up against the protrusion 112 increases due to the small volume of the protrusion 112.

[0126] FIG. 14 is a photograph showing processing marks for each area ratio of the protrusion portion according to the embodiment.

[0127] The area ratio of the protrusion 112 to the processing mark 111 of the isolated dot was 0.1% in Figure 14(a), 3% in Figure 14(b), 6% in Figure 14(c), and 22% in Figure 14(d), and it was found that visibility decreased significantly when it exceeded 10%.

[0128] That is, as already mentioned, protrusions are good, but if the area of ​​the protrusions is too large, the transmitted components in that area will increase, causing reduced visibility. If the protrusion area ratio (area of ​​protrusions / area of ​​processing marks) exceeds 10%, the difference in visibility becomes significantly noticeable even in processed areas. It is good for the protrusion area ratio to be 10% or less, and it is desirable for the area to be 4% or less.

[0129] FIG. 15 is a schematic diagram showing the relationship between the dot pitch and the processing radius according to the embodiment.

[0130] Fig. 15(a) shows the radius ri of the protrusion 112 and the radius r0 of the processing mark 111. Fig. 15(b) shows the dot pitch P when performing solid processing.

[0131] Here, it is desirable that the pitch P is greater than the diameter 2ri of the protrusions 112. This prevents adjacent protrusions 112 from interfering with each other, and maintains the elongated shape of the protrusions 112.

[0132] Furthermore, it is desirable that the pitch P>the radius ri of the protrusion 112+the radius r0 of the processing mark 111. This prevents the protrusion 112 from interfering with the adjacent processing mark 111, and maintains the shape of the protrusion 112.

[0133] Furthermore, by making the pitch P≦the diameter r1 of the processing marks 111, adjacent processing marks 111 can be formed continuously, thereby preventing a decrease in visibility due to the non-processed areas 113 between adjacent processing marks 111.

[0134] FIG. 16 is an explanatory diagram showing the relationship between the pitch and the boundary wall height according to the second embodiment shown in FIG. 12(c).

[0135] It was found that when the pitch P1 shown in FIG. 16(a) is larger than the pitch P2 shown in FIG. 16(b), the height Hb1 of the boundary shown in FIG. 16(a) is larger than the height Hb2 of the boundary shown in FIG. 16(b).

[0136] Specifically, when the diameter of the processing mark 111 of the isolated dot is 72 um and Dp=4 um, the experimental results are that Hb=3.0 um when the pitch P=70 um, and Hb=1.8 um when the pitch P=60 um.

[0137] FIG. 17 is a diagram illustrating processing marks in a square arrangement according to the embodiment.

[0138] Figure 17(a) is a schematic diagram of the processing marks arranged in a square plane filling structure, showing that the scanning was first performed from the upper left to the upper right, and then shifted down by one row. In this way, by setting the dot pitch appropriately, walls can be created at the boundary between dots, and processing marks can be created without gaps.

[0139] Figure 17(b) shows a cross section taken along the dashed line in Figure 17(a). The central protrusion is the highest, followed by the boundary walls between the dots.

[0140] Fig. 17(d) is a microscope image of the processing marks arranged in a square shape to create a solid image area. Fig. 17(c) is an image of the extracted features of the protrusions and boundary walls in Fig. 17(d).

[0141] The UV picosecond laser had a pulse energy of 35 uJ, a frequency of 500 kHz, a scanning speed of 30 m / sec, and main and sub-scanning pitches of 60 um.

[0142] The height difference Hp between the bottom of the processed mark and the protrusion was 9 um, the height difference Hb between the bottom of the processed mark and the boundary wall was 2 um, and the height difference (Hp-Dp) between the non-processed area and the protrusion was 4 um.

[0143] In this way, by irradiating the laser in an arrangement that allows for plane tessellation, it is possible to achieve processing that balances visibility and productivity. There are three types of regular polygons that can be tessellated: equilateral triangles, regular squares, and regular hexagons.

[0144] FIG. 18 is a diagram illustrating processing marks in a honeycomb arrangement according to an embodiment.

[0145] Figure 18(a) is a schematic diagram of the processing marks arranged in a honeycomb structure by shifting the drawing start position by half a dot for even and odd lines, and shows that the scanning was first performed from the top left to the bottom left, and then shifted by one row to the right. A honeycomb structure is a structure in which regular hexagons or regular hexagonal prisms are arranged without gaps. Figure 18(b) shows a cross section at the position of the dashed line in Figure 18(a).

[0146] Fig. 18(d) is a microscope image of the processing marks, and Fig. 18(c) is a diagram of the feature values ​​of the protrusions and boundary walls in Fig. 18(d), which shows that a regular hexagonal boundary wall has been formed. The scanning pitch is 64 um, which is a wider condition than Fig. 18.

[0147] A pulse energy of 20 to 60 uJ, a frequency of 500 k to 2 MHz, and main scanning and sub-scanning pitches of 40 to 100 um provide a good balance between productivity and visibility, and are therefore suitable.

[0148] By using such a structure, it is possible to realize marking with large reflected light and diffuse reflected light, or with high productivity.

[0149] FIG. 19 is a graph showing the relationship between the productivity ratio and the quality evaluation result.

[0150] Regarding the relationship between the productivity ratio and the quality evaluation result, the conventional Gaussian beam method is indicated by a square, and the embodiment is indicated by a black circle. The productivity ratio was calculated using main scanning pitch x sub scanning pitch.

[0151] Under the same productivity conditions as the conventional method, the quality (brightness) was about 15% higher, and under the same quality conditions as the conventional method, productivity was up 50%, meaning that a 1.5-fold productivity improvement can be expected.

[0152] The lightness, which indicates the quality, is expressed as L*=116*R^(1 / 3)-16, where R is the diffuse reflectance. It follows the law that the 1 / 3 power of a physical quantity matches human senses, and lightness of 30 or more is visible, and lightness of 40 or more is easily distinguishable and can be said to have good visibility.

[0153] Visibility value = b0 L*0 (1-exp(b1 ΔL*)) Formula (1) In formula (1), L*0 represents the brightness of the image, ΔL* represents the difference between the brightness of the image and the brightness of the portion other than the image, b0 is a positive real number, and b1 is a negative real number.

[0154] FIG. 20 is a diagram showing types of beam profile conversion elements.

[0155] The beam profile conversion element 40 shown in FIG. 7 is an optical element for converting a Gaussian beam into a desired wavefront, such as a circular ring beam or an elliptical ring beam, and may be a DOE (diffractive optical element), a liquid crystal phase modulator (SLM), a radial polarization element, an axial polarization element, an axicon lens, an aspheric lens, or the like.

[0156] In particular, in the case of radial polarization elements, axial polarization elements, axicon lenses, and optical vortex elements, which have a singularity in the center of the beam, the area of ​​the singularity is narrow, making them suitable for creating very thin protrusions.

[0157] The DOE is an element capable of generating a two-dimensional phase distribution pattern, and may be an optical vortex wavefront, a conical wavefront, a multi-beam, an aberration, or a composite superposition of these.

[0158] Optical elements using a wavefront having a singular point within the effective area of ​​an incident beam are roughly divided into a polarization conversion type and a phase conversion type.

[0159] FIG. 20(a) shows a polarization conversion type, which is made by dividing a normally circular λ / 2 plate at equal angles and combining pieces with different crystal axis directions to form a circle.

[0160] FIG. 20(a) shows an example of eight divisions. With eight divisions, the crystal axis direction can be changed by 22.5 degrees for each section, and the sections can be arranged so that they form a 90-degree angle with the opposite side.

[0161] As shown in Figure 20(b), when the incident polarization plane is horizontal, radial polarization can be created, and as shown in Figure 20(c), when the incident polarization plane is vertical, azimuth polarization can be created.

[0162] As shown in the figure, the center becomes a singular point, so the intensity is greatly reduced and the intensity on the image plane becomes below the processing threshold. The light intensity passing through this singular point and its vicinity decreases, and if it is below the processing threshold, it is possible to create an area where no processing occurs.

[0163] Figure 20(d) is a schematic diagram of a vortex beam transformation as a phase transformation type. Figure 20(d) shows a phase distribution pattern produced by an SLM, etc., and the white stripes are discontinuous in the center, forming a singular point.

[0164] When a plane wave is passed through the phase distribution pattern shown in Fig. 20(d), a spiral wavefront is created with a singularity at the center, as shown in Fig. 20(e), and the wave is converted into a spiral vortex beam.

[0165] FIG. 20(f) shows an example of a beam profile conversion element using a conical lens, with the apex being the singular point.

[0166] A ring beam can also be created using an aspheric lens, but in the case of an element with a singular point, the area of ​​the singular point is narrow, so it is suitable for creating a very thin protrusion, which is suitable for visibility.

[0167] In addition, if you use a DOE or liquid crystal element, even if a singular point does not occur during element fabrication, the light intensity will decrease in the vicinity of the singular point of the design. And if it is below the processing threshold, it will not be processed.

[0168] FIG. 21 is a schematic diagram showing types of beam profiles according to the embodiment.

[0169] Figure 21(a) shows a beam profile with a large area where the central light intensity is below the processing threshold. This has the characteristic that a large ring can be processed with the same energy, but visibility tends to decrease.

[0170] Figure 21(b) shows a beam profile with a rectangular outer shape. The processing marks made by the laser with this beam profile are the highest protrusion in the center, followed by the sides. This is suitable for filling in gaps without gaps, such as solid processing.

[0171] Figure 21(c) shows an elliptical beam profile, which is suitable for processing containers with a large curvature and concave surface.

[0172] FIG. 21(d) shows the dashed ring beam profile.

[0173] The beam profile is not limited to these, and the region where the light intensity is less than the processing threshold may be arranged eccentrically from the center, or a plurality of regions may be arranged independently.

[0174] FIG. 22 is a schematic diagram of the intensity distribution near the image plane with and without wavefront aberration adjustment.

[0175] When astigmatism is superimposed on the laser, the intensity distribution shape changes from a vertically elongated ellipse to a horizontally elongated ellipse before and after the focal plane, as shown in the upper part of the figure. When marking a three-dimensional shape such as a bottle container, the target object straddles the focal position, so there is a risk of brightness change occurring due to changes in the vertical and horizontal pitch of the solid image. In other words, it is ideal for the intensity distribution shape to remain unchanged before and after the focal plane, and it is desirable for the aspect ratio to change as little as possible.

[0176] Therefore, using the wavefront aberration control unit 30 shown in FIG. 7, the focal position shift amount derived from the three-dimensional shape and effective range of the workpiece is calculated, and the aspect ratio is adjusted within that range so that it falls within the desired range, as shown in the lower part of the figure.

[0177] By disposing the wavefront aberration control unit 30 in front of the beam profile conversion element 40, it becomes possible to change the beam to an ideal light intensity, thereby improving visibility and productivity.

[0178] As an optical system for correcting the aberration of the incident beam, there are methods that use spatial light modulators (SLMs) and lenses and mirrors. SLMs have the advantage of being able to generate any two-dimensional phase wavefront. However, there are issues with light utilization efficiency and light resistance. As for lenses, there is a method that combines multiple cylindrical lenses. There is also a method that generates an aberration wavefront by combining aspheric lenses. The lens method is suitable for light utilization efficiency and light resistance, but there is an issue that wavefront adjustment is difficult.

[0179] Among the wavefront aberrations, the ones that have the greatest effect on the low-orders are the 0 and 45 degree astigmatism. Tilt and spherical aberration can be adjusted by changing the mirror and lens positions, but astigmatism cannot be corrected.

[0180] FIG. 23 is a diagram showing the configuration of an aberration control mirror as an example of the wavefront aberration control unit 30, in which the mirror is intentionally deformed by pressing in order to control the wavefront aberration, particularly astigmatism.

[0181] Fig. 23(a) shows a front view, and Fig. 23(b) shows a cross-sectional view. Pressing members 310 for pressing the mirror 300 are arranged in the up, down, left and right directions on the beam incident surface side of the holding member 320 of the mirror 300. In addition, pressing members 310 are arranged in the center of the mirror 300 on the back side of the holding member 320. Each of the pressing members 310 is configured so that the amount of pressing can be changed by a screw or the like.

[0182] In the above configuration, the amount of pressure applied to the pressing member 310 is adjusted based on a beam profiler or wavefront sensor placed on the image plane or on a target near the image plane so that the wavefront at the target becomes a desired wavefront.

[0183] When the top and bottom of the mirror 300 are strongly pressed, the generatrix of the mirror 300 is deformed in the vertical direction, and a vertical cylindrical wavefront is superimposed on the incident beam in the reflected light. When the left and right of the mirror 300 are strongly pressed, a horizontal cylindrical wavefront is superimposed. In this way, a combination of pressure from the top, bottom, left and right generates 45-degree astigmatism.

[0184] FIG. 24 is a diagram showing the optical adjustment flow.

[0185] First, a drawing area to be scanned by the laser is set (step S101), and a processing area in the optical axis direction is derived (step S102). The processing area corresponds to the focal position shift amount derived from the three-dimensional shape and effective range of the processing object described in FIG.

[0186] Next, the beam profile in the processing area derived in step S102 is measured (step S103), and the aspect ratio of the profile measured in step S103 is calculated (step S104).

[0187] It is determined whether the aspect ratio calculated in step S104 is within an allowable range (step S105), and if it is within the allowable range, the process ends.

[0188] On the other hand, if the aspect ratio calculated in step S104 is outside the allowable range, the wavefront aberration generation amount is adjusted as described with reference to FIG. 23 (step S106), and the process returns to step S103 to continue.

[0189] FIG. 25 is a diagram showing beam profiles with and without astigmatism adjustment, and shows a ring-shaped profile with an average minor axis and major axis of 60 μm.

[0190] In Fig. 25, Fig. 25(a) shows a profile without astigmatism adjustment. The beam shape is a vertically elongated ellipse, and the ellipse aspect ratio, which is the ratio of the minor axis to the major axis of the elliptical beam, is 0.81.

[0191] Figure 25(b) shows the beam profile with astigmatism adjustment. The ellipse aspect ratio is 1.03, which is a good result, and it can be seen that the circularity is better than without adjustment. The ellipse aspect ratio should be 15% or less, and 10% or less is even better.

[0192] ●Summary● [First aspect] A processing method according to one embodiment of the present invention is a processing method for marking the surface of a container 1, which is an example of a resin substrate, by irradiating a processing laser beam 20, in which the processing laser beam 20 has a beam profile such that processing marks 111 are formed on the surface around the protrusion 112, specifically in the area continuously surrounding the protrusion 112.

[0193] Specifically, the surface of the container 1 has an area where the light intensity inside the laser beam irradiated thereon is equal to or less than the processing threshold, and processing marks are formed in an area surrounding the area where the light intensity is equal to or less than the processing threshold.

[0194] This makes it possible to provide a container 1 that is more productive and has excellent visibility of the markings on the surface, as compared to a case using a Gaussian beam.

[0195] Specifically, compared to a Gaussian beam of the same beam diameter, the protrusions 112 and processing marks 111 form a fine uneven structure, making it possible to increase the component of diffuse reflected light, thereby improving the visibility of the marking.

[0196] Furthermore, compared to a Gaussian beam with the same irradiation energy, a larger area can be processed for the same visibility of the marking, thereby improving productivity.

[0197] [Second aspect] In the first embodiment, the wavefront aberration of the processing laser beam 20 is corrected in the optical path of the processing laser beam 20 .

[0198] This makes it possible to eliminate wavefront aberration inherent to the laser oscillator and optical components, and to maintain similarity in the light intensity distribution even at positions far from the focal position, enabling high-quality marking even if the container 1 has a three-dimensional shape such as a PET bottle.

[0199] [Third aspect] In the first or second embodiment, an optical system for generating wavefront aberration is provided in the optical path of the laser, and the relative distance between a focusing lens provided in the optical path of the laser and the laser irradiation position on the surface of container 1 is adjusted so that the aspect ratio of the laser light intensity distribution is approximately constant even when it changes due to the three-dimensional shape of container 1.

[0200] [Fourth aspect] In any of the first to third embodiments, an optical element having a singular point within the effective beam diameter of the processing laser beam 20 is provided in the optical path of the processing laser beam 20, thereby forming a beam profile.

[0201] This makes it possible to process very thin protrusions based on singular points in narrow areas while reducing laser energy loss, thereby improving the visibility of the marking.

[0202] [Fifth aspect] In any of the first to fourth embodiments, the processing laser beam 20 is irradiated onto the container 1 at a pitch such that the protrusions 112 remain.

[0203] This makes it possible to improve the visibility of the marking based on the protrusions 112 and also improve productivity.

[0204] [Sixth aspect] In the fifth embodiment, the pitch P is larger than the diameter 2ri of the protrusions 112. This prevents adjacent protrusions 112 from interfering with each other, and maintains the shape of the protrusions 112.

[0205] [Seventh aspect] In the sixth embodiment, the pitch P is larger than the radius ri of the protrusion 112 plus the radius r0 of the processing mark 111. This prevents the protrusion 112 from interfering with the adjacent processing mark 111, and maintains the shape of the protrusion 112.

[0206] [Eighth aspect] In the sixth or seventh embodiment, the processing laser beam 20 is irradiated in a raster scan manner by a deflector having a deflection surface, and the pitch is the length in at least one of the main scanning direction and the sub-scanning direction.

[0207] [Ninth aspect] In any of the first to eighth embodiments, marking is performed using a pulsed processing laser beam 20 having an ultraviolet or deep ultraviolet wavelength.

[0208] This allows the markings to be formed with a small amount of energy, ensuring visibility of the markings and improving productivity.

[0209] [Tenth aspect] A processing apparatus according to one embodiment of the present invention is a processing apparatus that marks the surface of a container 1 by irradiating a processing laser beam 20, and is equipped with a beam profile conversion element 40 that converts the beam profile of the processing laser beam 20 so that a processing mark 111 is formed around a protrusion 112 on the surface.

[0210] Specifically, the device comprises a laser light source 1 that emits a laser having a wavelength that is optically absorbed toward the surface of the container 1, a scanning lens 24 that uses a scanning unit 23 that deflects the laser beam to form an image on an image plane on the surface of the container 1, and a beam profile conversion element 40 that has an area where the light intensity inside the laser beam is below the processing threshold and that forms processing marks so as to surround the area below the processing threshold.

[0211] [Eleventh aspect] In the tenth embodiment, a wavefront aberration control unit 30 is provided as an example of an optical system for correcting the wavefront aberration of the processing laser beam 20 before the beam profile conversion element 40 in the optical path of the processing laser beam 20 .

[0212] [12th aspect] In the tenth or eleventh embodiment, the intensity of the laser at the center of the optical axis is below the processing threshold, and a processing mark is formed surrounding the optical axis to diffusely reflect the resin in the laser irradiated area on the surface of the container 1, so that a wavefront aberration control unit 30 is provided as an example of a means for controlling astigmatism before the beam profile conversion element 40 in the optical path of the laser.

[0213] [13th aspect] In any of the tenth to twelfth aspects, the beam profile conversion element 40 is an optical element having a singular point within the effective beam diameter of the processing laser beam 20 .

[0214] [14th aspect] In one embodiment of the present invention, the container 1 has markings that are visible due to processing marks 111 formed on the surface, and the processing marks 111 are formed around the protrusion 112, specifically in a region that continuously surrounds the protrusion 112.

[0215] [15th aspect] In the fourteenth embodiment, the height of the protrusion 112 is equal to or greater than the height of the non-processed region 113 surrounding the processing mark 111 .

[0216] This can further increase the component of diffusely reflected light due to the protrusions 112, thereby further improving the visibility of the marking.

[0217] [16th aspect] In the fourteenth or fifteenth embodiment, the area of ​​the protrusions 112 is 10% or less of the area of ​​the processing marks 111 .

[0218] This reduces the reduction in diffuse reflected light caused by the reduction in the area of ​​the processing marks 111, while increasing the component of diffuse reflected light based on the protrusions 112, thereby improving the visibility of the marking. [Explanation of symbols]

[0219] 1 Container 10 Cylinder shaft 111 Machining marks 112 Protrusion 113 Non-processing area 2 Laser irradiation unit (example of the irradiation unit) 20 Processing laser beam 21 Laser light source 22 Beam Expander 23 Scanning unit (an example of a deflection means) 24 Scanning lens (an example of a scanning lens means) 25 Synchronous detection unit 30 Wavefront aberration control unit (an example of an optical system that corrects wavefront aberration) 40 Beam profile conversion element (an example of a beam profile conversion means) 3 Rotation mechanism (example of a rotating part) 4. Moving mechanism (an example of a moving part) 5 Dust collection section 6 Control section 61 First pattern data input section 62 Second pattern parameter specification section 621 Processing parameters 63 Storage area 631 Compatible Table 64 Processing data generation unit 641 Processing Data 65 Laser irradiation control unit 651 Light Intensity Control Unit 652 Pulse control section 66 Laser scanning control unit 67 Container rotation control unit 68 Container movement control section 69 Dust collection control section 100 Manufacturing equipment

Claims

1. A processing method for marking a surface of a resin substrate by irradiating the surface with a laser, comprising the steps of: The processing method has an area inside the laser beam irradiated to the resin substrate where the light intensity is below a processing threshold, and forms processing marks in an area surrounding the area below the processing threshold.

2. 2. The processing method according to claim 1, further comprising the step of correcting wavefront aberration of the laser in the optical path of the laser.

3. 2. The processing method according to claim 1, further comprising: an optical system for generating wavefront aberration in an optical path of the laser; and adjusting a relative distance between a focusing lens provided in the optical path of the laser and an irradiation position of the laser on the resin base material so that an aspect ratio of the light intensity distribution of the laser is approximately constant even when the relative distance changes in accordance with a three-dimensional shape of the resin base material.

4. 2. The processing method according to claim 1, wherein the beam profile is formed by providing an optical element having a singular point within an effective beam diameter of the laser in an optical path of the laser.

5. 2. The processing method according to claim 1, wherein the resin base material is irradiated with the laser at a pitch such that the protrusions remain.

6. The processing method according to claim 5 , wherein the pitch is larger than a diameter of the protrusions.

7. The processing method according to claim 6 , wherein the pitch is larger than a sum of a radius of the protrusion and a radius of the processing mark.

8. 8. The processing method according to claim 6, wherein the laser is irradiated in a raster scan manner by a deflector having a deflecting surface, and the pitch is a length in at least one of a main scanning direction and a sub-scanning direction.

9. 2. The method according to claim 1, wherein marking is performed using a pulsed laser having a wavelength of ultraviolet or deep ultraviolet.

10. A processing device that marks a surface of a resin substrate by irradiating the surface with a laser, a laser light source that emits a laser having a wavelength that is optically absorbed by the resin base material; a scanning lens means for forming an image on an image plane of the resin substrate using a deflection means for deflecting the laser beam; a beam profile conversion means for converting a processed mark having a region inside the laser beam where the light intensity is equal to or less than a processing threshold value and surrounding the region equal to or less than the processing threshold value; A processing device equipped with the above.

11. 11. The processing apparatus according to claim 10, further comprising an optical system for correcting wavefront aberration of the laser, the optical system being provided before the beam profile conversion means in the optical path of the laser.

12. The processing apparatus according to claim 10, further comprising a means for controlling astigmatism before the beam profile conversion means in the optical path of the laser, so that the intensity of the laser at the center of the optical axis is below a processing threshold value, and a processing mark is formed surrounding the optical axis to diffusely reflect the resin in the laser irradiated area of ​​the resin substrate.

13. 11. The processing apparatus according to claim 10, wherein the beam profile conversion means is an optical element having a singular point within an effective beam diameter of the laser.

14. A resin substrate having a marking visible due to a processing mark formed on the surface, The processing mark is formed in a region surrounding the protrusion in the resin substrate.

15. The resin substrate according to claim 14 , wherein the height of the protrusion is equal to or greater than the height of the non-processed area surrounding the processing mark.

16. The resin substrate according to claim 14, wherein the area of ​​the protrusions is 10% or less of the area of ​​the processing marks.

17. A processing method for marking a surface of a resin substrate by irradiating the surface with a laser, comprising the steps of: The laser has a beam profile such that a processing mark is formed in an area surrounding a protrusion on the surface.

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