Laser processing device, and laser processing system

Abstract

To provide a laser processing device that can control a space between laser beams radiated onto a surface of an object with high accuracy.SOLUTION: A laser processing device has: a laser source; a light scanning part that causes laser beam emitted from the laser source to scan on a surface of an object; and a control part that controls emission timing of the laser beam by the laser source on the basis of a first signal which is a continuous signal having a first period, and a second signal which is a continuous signal having a second period shorter than the first period, thereby being capable of controlling a space between the laser beams radiated onto the surface of the object.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present disclosure relates to a laser processing apparatus and a laser processing system.

Background Art

[0002] Conventionally, a laser processing apparatus that performs processing by irradiating a surface of an object with laser light has been known.

[0003] As a laser processing apparatus, from the scanning speed of the irradiation point of laser light, an irradiation period of pulsed laser light required to irradiate the surface of a workpiece with pulsed laser light at spatially predetermined intervals is obtained, and the pulsed laser light is irradiated onto the surface of the workpiece at the irradiation period. A device that controls the switching of blocking or transmitting the pulsed laser light is disclosed (see, for example, Patent Document 1).

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the apparatus of Patent Document 1, the interval of the laser light irradiated on the surface of the workpiece is controlled by switching the blocking or transmitting of the pulsed laser light and thinning out the irradiation of the laser light irradiated at a predetermined period. For this reason, the pulsed laser light is irradiated only at a timing determined by a predetermined period, and the temporal control resolution is low. Therefore, there is room for improvement in the accuracy of controlling the interval of the laser light irradiated on the surface of an object such as a workpiece.

[0005] An object of the present disclosure is to provide a laser processing apparatus capable of highly accurately controlling the interval of laser light irradiated on the surface of an object.

Means for Solving the Problems

[0006] A laser processing apparatus according to one aspect of the present disclosure includes a laser light source, an optical scanning unit that scans the laser light emitted from the laser light source on the surface of an object, a first signal that is a continuous signal having a first period, and a second signal that is a continuous signal having a second period shorter than the first period. A control unit that controls the emission timing of the laser light by the laser light source based on the first signal and the second signal, and thereby controls the interval between the laser lights irradiated on the surface of the object.

Effect of the Invention

[0007] According to the present disclosure, it is possible to provide a laser processing apparatus capable of highly accurately controlling the interval between laser lights irradiated on the surface of an object.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Embodiments for Carrying Out the Invention

[0009] The laser processing apparatus and the laser processing system according to the embodiments of the present disclosure will be described in detail with reference to the drawings. However, the embodiments shown below are examples of a laser processing apparatus and a laser processing system for embodying the technical idea of the present embodiment, and are not limited thereto.

[0010] In addition, the dimensions, materials, shapes, relative arrangements, etc. of the components described in the embodiments are not intended to limit the scope of the present disclosure only thereto, but are merely illustrative examples unless otherwise specifically described. Note that the sizes, positional relationships, etc. of the members shown in each drawing may be exaggerated for clarity of explanation. Also, in the following description, the same names and reference numerals indicate the same or similar members, and detailed descriptions thereof will be omitted as appropriate.

[0011] [First Embodiment] <Configuration Example of Laser Processing Apparatus 100> (Overall Configuration) FIG. 1 is a schematic diagram showing an example of the configuration of a laser processing apparatus 100 according to the first embodiment of the present disclosure.

[0012] As shown in FIG. 1, the laser processing apparatus 100 includes a laser light source 1 and an optical scanning unit 2 that scans the laser light L emitted from the laser light source 1 on the surface of the object 200. Further, the laser processing apparatus 100 controls the emission timing of the laser light L by the laser light source 1 based on a first signal S1 that is a continuous signal having a first period and a second signal S2 that is a continuous signal having a second period shorter than the first period, and has a control unit 3 capable of controlling the interval of the laser light L irradiated on the surface of the object 200. In the example shown in FIG. 1, the laser processing apparatus 100 has a folding mirror 4.

[0013] In the example shown in FIG. 1, the laser light source 1 emits laser light L that is pulsed light. The laser light L emitted from the laser light source 1 is reflected by the folding mirror 4 and enters the reflecting surface 20 provided in the optical scanning unit 2. The optical scanning unit 2 scans the laser light L reflected by the reflecting surface 20 in the first direction X1 on the surface of the object 200 by swinging the reflecting surface 20 around the swing axis 21. The swing axis 21 is an axis substantially orthogonal to the first direction X1.

[0014] The laser processing apparatus 100 can form a desired image on the surface of the object 200 by controlling the emission of the laser light L from the laser light source 1 and switching between irradiation and non-irradiation of the laser light L scanned in the first direction X1 onto the surface of the object 200. The image formed on the surface of the object 200 includes characters, figures, photographs, codes, etc. The codes include barcodes or QR codes (registered trademarks), etc. The image formation may also be referred to as pattern formation or marking.

[0015] The swinging direction 22 represents the direction in which the reflecting surface 20 swings back and forth. The forward swinging direction 221 represents the swinging direction in the forward path of the reciprocating swing of the reflecting surface 20. In the example shown in FIG. 1, the optical scanning unit 2 scans the laser beam L in the X direction by swinging the reflecting surface 20 in the forward swinging direction 221. From another perspective, when the reflecting surface 20 swings in the reverse swinging direction, which is the direction opposite to the forward swinging direction 221, the laser processing apparatus 100 does not scan the laser beam L from the laser light source 1 by turning off the emission of the laser beam L from the laser light source 1.

[0016] When the reflecting surface 20 swings, when the swinging direction switches from the forward swing to the reverse swing, or from the reverse swing to the forward swing, the swing of the reflecting surface 20 decelerates from the constant speed state, and after the swinging direction switches, it accelerates to a predetermined swinging speed so as to return to the constant speed state again. During the period when the reflecting surface 20 is moving at a constant speed, the laser beam L reflected by the reflecting surface 20 is scanned at a constant speed on the surface of the object 200. Therefore, when the laser beam L is emitted from the laser light source 1 at a substantially constant period, the intervals between the laser beams L irradiated on the surface of the object 200 are substantially equal. Note that the interval of the laser beam L in the embodiment of the present disclosure means the interval between the laser beams L irradiated adjacent to each other on the surface of the object 200.

[0017] On the other hand, during the period when the reflecting surface 20 is performing either acceleration motion or deceleration motion, the laser beam L reflected by the reflecting surface 20 is scanned non-uniformly on the surface of the object 200. Therefore, when the laser beam L is emitted from the laser light source 1 at a substantially constant period, the intervals between the laser beams L irradiated on the surface of the object 200 vary according to the acceleration or deceleration of the scanning of the laser beam L. For example, the slower the swinging speed of the reflecting surface 20 becomes with respect to the predetermined swinging speed, the narrower the intervals between the laser beams L irradiated on the surface of the object 200 become.

[0018] Due to the variation in the interval of the laser beam L on the surface of the object 200, the processing position on the surface of the object 200 deviates from the desired position, thereby reducing the processing accuracy of the laser processing apparatus, such as the image formation accuracy. On the other hand, in order to reduce the reduction in processing accuracy caused by the non-uniform speed scanning of the laser beam L, when the reflecting surface 20 is accelerating and decelerating, the emission of the laser beam L from the laser light source 1 is turned off so that processing is not performed, the processing productivity decreases due to the longer period during which processing cannot be performed.

[0019] The laser processing apparatus 100 can control the interval of the laser beam L irradiated on the surface of the object 200 by controlling the emission timing of the laser beam L by the laser light source 1. Thereby, the laser processing apparatus 100 can reduce the reduction in processing accuracy. Further, the laser processing apparatus 100 controls the emission timing of the laser beam L by the laser light source 1 based on a first signal S1 that is a continuous signal having a first period and a second signal S2 that is a continuous signal having a second period shorter than the first period. Thereby, in the laser processing apparatus 100, compared with the case where the emission timing of the laser beam L is controlled by using only the first signal S and thinning out the first signal S by switching the blocking or transmission of the laser beam L, the interval of the laser beam L irradiated on the surface of the object 200 can be controlled with high precision.

[0020] As described above, in the embodiment of the present disclosure, it is possible to provide a laser processing apparatus 100 that can control the interval of the laser beam L irradiated on the surface of the object 200 with high precision. Further, by controlling the interval of the laser beam L irradiated on the surface of the object 200 with high precision, the processing accuracy of the laser processing apparatus 100 can be increased. Furthermore, since processing can be performed even during the period when the reflecting surface 20 is accelerating and decelerating, the processing productivity of the laser processing apparatus 100 can be improved.

[0021] In the laser processing apparatus 100, correspondence information regarding the relationship between the timing of the first signal S1 with respect to the reference signal Sg and the number of signals of the second signal S2 corresponding to the time shift from the timing of the first signal S1 can be determined in advance. Based on the timing of the first signal S1 with respect to the reference signal Sg, the control unit 3 causes the laser light source 1 to emit the laser light L at a timing shifted from the timing of the first signal S1 according to the number of signals of the second signal S2 obtained by referring to the above correspondence information. Thereby, the laser processing apparatus 100 can control the emission timing of the laser light L by the laser light source 1 with high precision.

[0022] In FIG. 1, the object 200 is an object whose surface is to have an image formed thereon by the laser processing apparatus 100. Note that FIG. 1 schematically shows only the surface of the object 200. The object 200 is, for example, a container made of resin (hereinafter referred to as a resin container). More specifically, the object 200 is a PET (Polyethylene Terephthalate) bottle or the like. The PET bottle is a resin container for storing beverages and the like.

[0023] Here, in recent years, resin containers such as PET bottles are required to take measures to reduce the resin containers discarded into the ocean and the like and to realize a sustainable society. If a resin container that is easy to recycle or a technology for promoting the recycling of resin containers can be established, the resin containers discarded into the ocean and the like can be reduced, and the recyclability of the resin containers can be improved. Then, a recycling-based society that effectively uses limited resources can be realized. Note that the term "recycle" in this specification means that a recycling company collects and flakes used resin containers that have been sorted and recycled, and manufactures resin containers again.

[0024] In order to promote the recycling of resin containers, it is desirable to thoroughly separate and collect resin containers by raw material. On the other hand, resin containers are often provided with sheet-like labels that display product information such as the manufacturer, production location, and contents. For separate collection, it is necessary to remove the sheet-like label from the resin container. However, since the operation of removing the label from the resin container is time-consuming, the resin container may be collected without the label being removed. Therefore, the sheet-like label on the resin container is one of the factors that inhibits the separate collection of resin containers.

[0025] The laser processing apparatus 100 can directly form an image including product information on the surface of a resin container such as a PET bottle. Thereby, product information can be displayed on the resin container without attaching a sheet-like label. As a result, the operation of removing the label from the resin container, which inhibits separate collection, can be eliminated, and the recycling of resin containers can be promoted. Note that the object 200 is not limited to a resin container such as a PET bottle, and may be an object composed of various materials.

[0026] In FIG. 1, the laser light source 1 emits pulsed laser light L in accordance with an emission control signal Dr supplied from the control unit 3. As the laser light source 1, a solid laser such as a YAG laser, a semiconductor laser, a fiber laser, etc. can be appropriately selected according to the material of the object 200 and the like. The repetition frequency of the emission of the laser light L, the output (light intensity) of the laser light source 1, the wavelength of the laser light L, etc. can also be appropriately determined according to the material of the object 200 and the required processing time and the like.

[0027] For the optical scanning unit 2, a galvanometer mirror, a MEMS (Micro Electro Mechanical Systems) mirror, or the like can be used. From the perspective of reducing damage caused by the laser beam L, it is preferable to use a galvanometer mirror that has resistance to high-power laser light. Also, an acousto-optic element, a polygon mirror, or the like can be used for the optical scanning unit 2. Even when the laser processing apparatus 100 uses an acousto-optic element or a polygon mirror for the optical scanning unit 2, it can reduce the variation in the interval of the laser beam L on the surface of the object 200 due to these non-uniform motions.

[0028] In addition, the optical scanning unit 2 can scan the laser beam L not only in the first direction X1 but also in a direction orthogonal to the X1 direction, for example, in the direction along the swing axis 21. The laser processing apparatus 100 can form a two-dimensional image on the surface of the object 200 by scanning the laser beam L in each of the first direction X1 and the direction along the swing axis 21. However, the laser processing apparatus 100 can also form a two-dimensional image on the surface of the object 200 by scanning the laser beam L in the first direction X1 and relatively moving the object 200 in the direction along the swing axis 21. Note that the optical scanning unit 2 may be driven under the control of the control unit 3 or may be independently driven with respect to the control unit 3.

[0029] The control unit 3 can control the emission of the laser beam L from the laser light source 1 based on the image data Im, the reference signal Sg, the first signal S1, etc. supplied from an external device such as an external controller. Details of the configuration of the control unit 3 will be described below with reference to FIGS. 2 and 3.

[0030] The image data Im is data that serves as the basis for the image to be formed on the object 200. The control unit 3 can control the emission of the laser beam L by the laser light source 1 based on the image data Im in addition to the first signal S1 and the second signal S2. Thereby, the laser processing apparatus 100 can form an image corresponding to the image data Im on the surface of the object 200.

[0031] The reference signal Sg is, for example, a pulse signal that determines the image formation start position on the surface of the object 200 in the first direction X1. The reference signal Sg is supplied to the control unit 3 once for each single scan of the laser beam L in the first direction X1. By supplying the reference signal Sg to the control unit 3, the control unit 3 can be given the image formation timing in the first direction X1.

[0032] The first signal S1 is, for example, a continuous pulse signal having a first period. The first period is predetermined such that the laser beam L is irradiated on the surface of the object 200 at a predetermined interval when the reflecting surface 20 moves at a constant speed with a predetermined swinging speed.

[0033] The folding mirror 4 guides the laser beam L from the laser light source 1 to the reflecting surface 20 by reflecting it. The folding mirror 4 preferably has a high reflectivity with respect to the laser beam L in order to reduce damage caused by the laser beam L. For example, a dielectric multilayer mirror can be used for the folding mirror 4. However, the configuration for guiding the laser beam L to the reflecting surface 20 is not limited to the folding mirror 4, and one or more optical elements may be used, or the laser beam L may be directly incident on the reflecting surface 20.

[0034] (Configuration of the control unit 3) ((Hardware configuration)) FIG. 2 is a block diagram showing an example of the hardware configuration of the control unit 3 included in the laser processing apparatus 100 according to the first embodiment of the present disclosure. As shown in FIG. 2, the control unit 3 includes an FPGA (field programmable gate array) 301 and a ROM (Read Only Memory) 302. The control unit 3 also includes a RAM (Random Access Memory) 303 and an I / F (Interface) 304. These are connected to be communicable with each other via a system bus B.

[0035] The FPGA 301 executes control processing including various arithmetic operations. The ROM 302 can store data used to drive the FPGA 301 and various information such as correspondence information described later. The RAM 303 is used as a work area for the FPGA 301. The I / F 304 is an interface for connecting the control unit 3 to various devices. The devices here include the laser light source 1 and an external controller that supplies the first signal S1 etc. to the control unit 3.

[0036] ((Functional Configuration)) FIG. 3 is a block diagram showing an example of the functional configuration of the control unit 3 included in the laser processing apparatus 100 according to the first embodiment of the present disclosure. As shown in FIG. 3, the control unit 3 includes a second signal generation unit 31, a storage unit 32, a determination unit 33, an emission control unit 34, and an output unit 35. The function of the output unit 35 is realized by the I / F 304 etc. The function of the storage unit 32 is realized by a non-volatile memory such as the ROM 303. The functions of the second signal generation unit 31, the determination unit 33, and the emission control unit 34 are realized by the FPGA 301 etc. Note that a part of the above functions may be realized by an external device such as a PC (Personal Computer) or a server, or may be realized by distributed processing between the control unit 3 and the external device.

[0037] Also, each function included in the control unit 3 can also be realized by one or a plurality of processing circuits. Here, the "processing circuit" in this specification includes a processor such as a CPU (Central Processing Unit) programmed to execute each function by software like a processor implemented by an electronic circuit, an ASIC (Application Specific Integrated Circuit), a DSP (digital signal processor) designed to execute each function described above, and devices such as conventional circuit modules.

[0038] The second signal generation unit 31 generates a second signal S2 and supplies it to the determination unit 33. The second signal S2 is, for example, a clock signal generated by a clock oscillation circuit provided in the FPGA 301. The clock signal is used not only as the second signal S2 but also for timing alignment among a plurality of circuits when the logic circuits provided in the FPGA 301 and the like operate. In the embodiment of the present disclosure, by using a clock signal as the second signal S2, the clock oscillation circuit provided in the FPGA 301 can be used for generating the second signal S2. As a result, since there is no need to provide a dedicated circuit for generating the second signal S2, the configuration of the control unit 3 can be simplified.

[0039] The storage unit 32 stores the correspondence information 320. The correspondence information 320 is information regarding the relationship between the timing of the first signal S1 with respect to the reference signal Sg and the number of signal counts of the second signal S2 corresponding to the time shift from the timing of the first signal S1. Table 1 shown below shows an example of the correspondence information between the timing of the first signal S1 and the number of signal counts of the second signal S2 in the laser processing apparatus 100.

Table 1

[0040] The correspondence information 320 is determined in advance and stored in the storage unit 32. Note that the storage unit 32 may be provided in an external device such as a PC communicably connected to the control unit 3 by wire or wirelessly, or an external server communicably connected to the control unit 3 via a network. However, when the control unit 3 of the laser processing apparatus 100 has the storage unit 32, it is not necessary to prepare an environment for communicating with an external device, so the configuration of the laser processing apparatus 100 can be simplified.

[0041] The determination unit 33 determines the emission timing of the laser beam L by the laser light source 1 based on the first signal S1 and the second signal S2. In the example shown in FIG. 3, the determination unit 33 inputs the image data Im, the reference signal Sg, and the first signal S1 respectively from an external controller.

[0042] During the period when the reflecting surface 20 of the optical scanning unit 2 shown in FIG. 1 is moving at a constant speed, the determination unit 33 determines the emission timing of the laser beam L according to the first signal S1. On the other hand, during the period when the reflecting surface 20 of the optical scanning unit 2 is moving at a non-constant speed such as accelerating or decelerating, the determination unit 33 refers to the correspondence information 320 based on the timing of the first signal S1 with respect to the reference signal Sg, and determines the emission timing as the timing shifted from the timing of the first signal S1 according to the number N of signals of the second signal S2 obtained.

[0043] For example, let the first period in the first signal S1 be 1 μs and the second period in the second signal S2 be 0.01 μs. In Table 1, assume that the timing t13 of the first signal S1 with respect to the reference signal Sg is one timing during the period when the reflecting surface 20 is moving at a non-constant speed. When the deviation of the timing of the first signal S1 corresponding to the accelerating or decelerating motion of the reflecting surface 20 is 0.03 μs, the number N13 of signals of the second signal S2 corresponding to this timing deviation is 0.03 / 0.01 = 3 (pieces). The determination unit 33 acquires the number N13 of signals of the second signal S2 by referring to the correspondence information 320 based on the timing t13. The determination unit 33 can determine the timing shifted from the first signal S1 by 0.03 μs corresponding to the acquired number N13 of signals as the emission timing.

[0044] The length of the second period can be appropriately selected as long as it is shorter than the length of the first period. However, from the viewpoint of precisely controlling the interval of the laser beam L irradiated on the surface of the object 200, the length of the second period is preferably 1 / 10 or less of the length of the first period.

[0045] The emission control unit 34 controls the emission of the laser beam L from the laser light source 1. For example, the emission control unit 34 controls the emission of the laser beam L from the laser light source 1 so that the laser beam L is emitted at the timing determined by the determination unit 33.

[0046] The output unit 35 can control the communication between the control unit 3 and the laser light source 1 according to the command from the emission control unit 34.

[0047] <Operation Example of Laser Processing Apparatus 100> With reference to FIGS. 4 to 10, the operation of the laser processing apparatus 100 will be described. Here, the specifications of the laser processing apparatus 100 that are premised in the description of the operation of the laser processing apparatus 100 are shown in Table 2 below. However, the present disclosure is not limited to the specification values shown in Table 2 at all. [Table 2]

[0048] FIG. 4 is a diagram showing an example of a scanning region A in the first direction X1 of the laser processing apparatus 100 according to the first embodiment of the present disclosure. FIG. 4 schematically shows the surface of the object 200 viewed from a direction orthogonal to the cylindrical axis when the object 200 is a cylindrical resin container.

[0049] In FIG. 4, the scanning region A is a region where the laser beam L is scanned in the first direction X1 by the optical scanning unit 2. The scanning region A includes a first region A1 where the scanning of the laser beam L is accelerated, a second region A2 where the scanning speed of the laser beam L is constant, and a third region A3 where the scanning of the laser beam L is decelerated.

[0050] FIG. 5 is a diagram showing an example of the scanning position of the laser beam L during the scanning period Ta in the first direction X1 of the laser processing apparatus 100 according to the first embodiment of the present disclosure. In FIG. 5, the horizontal axis represents time t, and the vertical axis represents the position X of the laser beam L. The graph Ga represents the position of the laser beam L according to time t. The slope of the graph Ga corresponds to the scanning speed of the laser beam L.

[0051] The relationship between time t and position X is represented by the following formula (1). In formula (1), the speed v0 represents the scanning speed when the laser beam L is scanned at a constant speed on the surface of the object 200. The acceleration a represents the acceleration when the scanning of the laser beam L is accelerated or decelerated on the surface of the object 200. Note that the acceleration is variable during the scanning period Ta, and the speed itself undergoes state transitions of acceleration, constant speed, and deceleration. [Equation]

[0052] The scanning period Ta is the period during which the laser beam L is scanned in the first direction X1. The laser beam L scans the scanning area A during the scanning period Ta. That is, the scanning period Ta and the scanning area A correspond to each other. The scanning period Ta includes a first period Ta1 during which the scanning speed of the laser beam L is accelerated, a second period Ta2 during which the scanning speed of the laser beam L is constant, and a third period Ta3 during which the scanning speed of the laser beam L is decelerated. The first period Ta1 corresponds to the scanning area A1, the second period Ta2 corresponds to the scanning area A2, and the third period Ta3 corresponds to the scanning area A3, respectively.

[0053] As shown in FIG. 5, in the second period Ta2, since the scanning speed of the laser beam L is substantially constant, the graph G becomes substantially linear. On the other hand, in the first period Ta1 and the third period Ta3, since the scanning of the laser beam L is accelerated or decelerated, the graph Ga becomes non-linear.

[0054] Next, FIG. 6 is a timing chart showing an example of the emission timing of the laser beam L in the first area A1 of the laser processing apparatus 100 according to the first embodiment of the present disclosure. FIG. 6 shows the timings of the second signal S2, the reference signal Sg, the first signal S1, and the emission control signal Dr in order from the upper stage to the lower stage. Note that the periods of the signals shown in FIG. 6 are modified for easy viewing and may not accurately represent the actual periods. This also applies to the timing charts shown hereinafter. The emission control signal Dr includes an emission control signal Dr11, an emission control signal Dr120, an emission control signal Dr121, an emission control signal Dr122, and an emission control signal Dr13. The emission control signal Dr11 and the emission control signal Dr120 represent the emission control signal Dr in the first period Ta1 during which the scanning of the laser beam L is accelerated. The emission control signal Dr121 and the emission control signal Dr13 represent the emission control signal Dr in the second period Ta2 during which the laser beam L is scanned at a constant speed. The first signal S12 represents one pulse signal in the first signal S1.

[0055] In the second period Ta2, the period of the injection control signal Dr is approximately equal to the first period P1. On the other hand, in the first period Ta1, the injection control signal Dr is supplied to the laser light source 1 (see FIG. 1) at a timing shifted from the first period P1 in accordance with the acceleration of the scanning of the laser beam L. For example, the injection control signal Dr120 is supplied to the laser light source 1 at a delayed timing by a time shift δ1 with respect to the first signal S12. In the example shown in FIG. 6, the time shift δ1 corresponds to 13 signal numbers corresponding to the first signal S12 defined in the correspondence information 320. The laser light source 1 emits the laser beam L at a delayed timing by the time shift δ1.

[0056] The following Table 3 shows the time differences between the injection control signal Dr11 and the injection control signal Dr120, between the injection control signal Dr120 and the injection control signal Dr121, and between the injection control signal Dr121 and the injection control signal Dr122, respectively. Note that each value of the time differences shown in Table 3 is calculated based on the above-described formula (1) and the specification values in Table 2. The number of signals of the second signal S2 obtained by dividing each time difference by the second period P2 is associated with the first signal S1 and stored in the correspondence information 320.

Table 3

[0057] FIG. 7 is a timing chart showing an example of the emission timing of the laser beam L in the third region A3 of the laser processing apparatus 100 according to the first embodiment of the present disclosure. Each signal shown in FIG. 7 is the same as that in FIG. 6. The emission control signal Dr includes an emission control signal Dr21, an emission control signal Dr22, an emission control signal Dr230, an emission control signal Dr231, an emission control signal Dr232, and an emission control signal Dr233. The emission control signal Dr21 and the emission control signal Dr22 represent the emission control signals in the second period Ta2 during which the laser beam L is scanned at a constant speed. The emission control signal Dr230, the emission control signal Dr231, the emission control signal Dr232, and the emission control signal Dr233 represent the emission control signals in the third period Ta3 during which the scanning of the laser beam L is decelerated. The first signal S24 represents one pulse signal in the first signal S1.

[0058] In the second period Ta2, the period of the emission control signal Dr is substantially equal to the first period P1. On the other hand, in the third period Ta3, the emission control signal Dr is supplied to the laser light source 1 (see FIG. 1) at a timing shifted from the first period P1 in response to the deceleration of the scanning of the laser beam L. For example, the emission control signal Dr231 is supplied to the laser light source 1 at a timing delayed by a time shift δ2 with respect to the first signal S24. The time shift δ2 corresponds to one signal number corresponding to the first signal S24 defined in the correspondence information 320. The laser light source 1 emits the laser beam L at a timing delayed by the time shift δ2.

[0059] Table 4 below shows the time differences between the emission control signal Dr230 and the emission control signal Dr231, between the emission control signal Dr231 and the emission control signal Dr232, and between the emission control signal Dr232 and the emission control signal Dr233, respectively. Note that each value of the time differences shown in Table 4 is calculated based on the above-described formula (1) and the specification values in Table 2. The signal numbers of the second signal S2 obtained by dividing each time difference by the second period P2 are associated with the first signal S1 and stored in the correspondence information 320.

Table 4

[0060] FIG. 8 is a diagram showing the interval Δ between laser beams L irradiated on the surface of the object 200 in the laser processing apparatus 100 according to the first embodiment of the present disclosure. As shown in FIG. 8, in the laser processing apparatus 100, the interval Δ between the laser beams L irradiated on the surface of the object 200 is substantially equal in any of the first period Ta1, the second period Ta2, and the third period Ta3.

[0061] As described above, in the laser processing apparatus 100, the scanning region A of the laser beam on the surface of the object 200 includes a first region A1 where the scanning of the laser beam L is accelerated, a second region A2 where the scanning speed of the laser beam L is constant, and a third region A3 where the scanning of the laser beam L is decelerated. In the second region A2, the control unit 3 causes the laser light source 1 to emit the laser beam L based on the first signal S1. In the first region A1 and the third region A3, the control unit 3 causes the laser light source 1 to emit the laser beam L based on the first signal S1 and the second signal S2. Thereby, in the laser processing apparatus 100, the interval between the laser beams L irradiated on the surface of the object 200 can be controlled with high precision, and the intervals between the laser beams L irradiated on the surface of the object 200 can be made substantially equal over the entire scanning region A. Further, in the laser processing apparatus 100, by controlling the interval between the laser beams L irradiated on the surface of the object 200 with high precision, the processing accuracy by the laser processing apparatus 100 can be increased. Furthermore, since processing can be performed even during the period when the reflecting surface 20 is performing accelerated and decelerated motions, the productivity of processing by the laser processing apparatus 100 can be improved. Note that, as will be described later, in the second region A2 as well, the laser light source 1 may emit the laser beam L based on the first signal S1 and the second signal S2. Details will be described later.

[0062] Next, FIG. 9 is a diagram showing an example of interval control of the laser beam L at the boundary between the first region A1 and the second region A2 of the laser processing apparatus 100 according to the first embodiment of the present disclosure. In the example shown in FIG. 9, on the surface of the object 200, the laser beam L11 is irradiated on the first region A1, and the laser beams L22 and L23 are irradiated on the second region A2. The region between the laser beam L11 and the laser beam L12 straddles the first region A1 and the second region A2.

[0063] In FIG. 9, the distance d11 is the distance between the boundary between the first region A1 and the second region A2 and the center of the laser beam L11. The distance d21 is the distance between the boundary between the first region A1 and the second region A2 and the center of the laser beam L21. When the distance d11 is 90 μm and the distance d21 is 10 μm, the time from when the laser beam L11 is irradiated until the laser beam L enters the second region A2 is 0.908 μs. The timing of irradiating the next laser beam L at a position 10 μm from the start position of the second region A2 is 0.100 μs after the laser beam L enters the second region A2. Therefore, the time difference between the laser beam L11 and the laser beam L21 is 0.908 + 0.100 = 1.008 μs.

[0064] Table 5 below shows the time differences between the laser beam L11 and the laser beam L21, and between the laser beam L21 and the laser beam L22, respectively. Note that each value of the time differences shown in Table 5 is calculated based on the above-described formula (1) and the specification values in Table 2. The number of signals of the second signal S2 obtained by dividing each time difference by the second period P2 is associated with the first signal S1 and stored in the correspondence information 320.

Table 5

[0065] By emitting the laser beam L with the time differences shown in Table 5, the laser processing apparatus 100 can make the interval between the laser beams L on the surface of the object 200 approximately 100 μm even when the region between adjacent laser beams L straddles the first region A1 and the second region A2.

[0066] Next, FIG. 10 is a diagram showing an example of interval control of the laser beam L at the boundary between the second region A2 and the third region A3 of the laser processing apparatus 100 according to the first embodiment of the present disclosure. In the example shown in FIG. 10, on the surface of the object 200, the laser beam L23 is irradiated onto the second region A2, and the laser beam L31 is irradiated onto the third region A3. The region between the laser beam L23 and the laser beam L31 straddles the second region A2 and the third region A3.

[0067] In FIG. 10, the distance d22 is the distance between the boundary between the second region A2 and the third region A3 and the center of the laser beam L23. The distance d31 is the distance between the boundary between the second region A2 and the third region A3 and the center of the laser beam L31. When the distance d22 is 50 μm and the distance d31 is 50 μm, the time from when the laser beam L23 is irradiated until the laser beam L enters the third region A3 is 0.500 μs. The timing of irradiating the next laser beam L at a position 50 μm from the start position of the third region A3 is 0.503 μs after the laser beam L enters the third region A3. Therefore, the time difference between the laser beam L11 and the laser beam L21 is 0.500 + 0.503 = 1.003 μs. The number of signals of the second signal S2 obtained by dividing each time difference calculated in the same manner as above by the second period P2 is associated with the first signal S1 and stored in the correspondence information 320.

[0068] In the description of the first embodiment of the present disclosure, the case where the acceleration and deceleration in the scanning of the laser beam L are at a constant acceleration is exemplified, but the present disclosure is not limited thereto. The time difference and the number of signals of the second signal S2 can also be calculated according to the characteristics of the optical scanning unit 2 shown in FIG. 1.

[0069] [Second Embodiment] Next, a laser processing apparatus according to the second embodiment of the present disclosure will be described. Note that the same names and reference numerals as those in the above-described embodiment denote the same or similar members, and detailed descriptions thereof will be omitted as appropriate.

[0070] FIG. 11 is a diagram showing scanning in the first direction X1 and the second direction X2 of the laser processing apparatus according to the second embodiment of the present disclosure. In the present embodiment, the light scanning unit included in the laser processing apparatus according to the second embodiment of the present disclosure can scan laser light in each of the first direction X1 and the second direction X2 which is the direction opposite to the first direction X1, which is different from the first embodiment described above. In the second embodiment of the present disclosure, since the laser light can be scanned in both the first direction X1 and the second direction X2, processing can be performed in both the first direction X1 and the second direction X2, so that the productivity of processing by the laser processing apparatus can be improved.

[0071] FIG. 12 is a diagram showing the scanning positions of the laser light in the scanning period Ta in the first direction X1 and the scanning period Tb in the second direction X2 of the laser processing apparatus according to the second embodiment of the present disclosure. In FIG. 12, the horizontal axis represents time t, and the vertical axis represents the position X of the laser light on the surface of the object 200. The graph Ga represents the position of the laser light on the surface of the object 200 according to the time t during the scanning period Ta. The graph Gb represents the position of the laser light on the surface of the object 200 according to the time t during the scanning period Tb. The slopes of the graph Ga and the graph Gb correspond to the scanning speed of the laser light. The relationship between the time t and the position X is represented by the above-described formula (1).

[0072] The scanning period Ta is the period during which the laser light is scanned in the first direction X1. The scanning period Ta and the graph Ga are the same as those shown in FIG. 5. The direction switching period Cr is the period for switching the direction in which the laser light is scanned from the first direction X1 to the second direction X2, or from the second direction X2 to the first direction X1.

[0073] The scanning period Tb is the period during which the laser beam is scanned in the second direction X2. The laser beam scans the scanning region A shown in FIG. 4 during the scanning period Tb. That is, the scanning period Tb and the scanning region A correspond to each other. The scanning period Tb includes a first period Tb1 during which the scanning speed of the laser beam is accelerated, a second period Tb2 during which the scanning speed of the laser beam L is constant, and a third period Tb3 during which the scanning speed of the laser beam L is decelerated. The first period Tb1 and the scanning region A3 correspond to each other. The second period Tb2 and the scanning region A2 correspond to each other. The third period Tb3 and the scanning region A1 correspond to each other.

[0074] In the second period Tb2, since the scanning speed of the laser beam is substantially constant, the graph Gb becomes substantially linear. On the other hand, in the first period Tb1 and the third period Tb3, since the scanning of the laser beam is accelerated or decelerated, the graph Gb becomes non-linear.

[0075] In the second embodiment of the present disclosure, as shown in FIGS. 11 and 12, even when the laser beam is scanned in each of the first direction X1 and the second direction X2, the same operational effects as those of the first embodiment can be obtained.

[0076] Here, in the optical scanning unit included in the laser processing apparatus, the acceleration and deceleration characteristics may be different between the scanning of the laser beam in the first direction X1 and the scanning of the laser beam in the second direction X2. Therefore, in the embodiment of the present disclosure, the correspondence information regarding the relationship between the timing of the first signal with respect to the reference signal Sg and the number of signals of the second signal S2 corresponding to the time shift from the timing of the first signal can be made different between the scanning of the laser beam in the first direction X1 and the scanning of the laser beam in the second direction X2. In other words, in the embodiment of the present disclosure, the correspondence information referred to in the scanning in the first direction X1 may be the first correspondence information, and the correspondence information referred to in the scanning in the second direction X2 may be second correspondence information different from the first correspondence information. Here, the first correspondence information is information regarding the relationship between the timing of the first signal and the number of signals of the second signal S2 in the scanning in the first direction X1. The second correspondence information is information regarding the relationship between the timing of the first signal and the number of signals of the second signal S2 in the scanning in the second direction X2.

[0077] Table 6 shown below shows an example of the second correspondence information.

Table 6

[0078] In the embodiments of the present disclosure, by varying the correspondence information between the scanning in the first direction X1 and the scanning in the second direction X2, even when the acceleration and deceleration characteristics are different between the scanning of the laser beam in the first direction X1 and the scanning of the laser beam in the second direction X2, the interval between the laser beams irradiated on the surface of the object can be controlled with high precision.

[0079] Note that the operational effects other than those described in the embodiments of the present disclosure are the same as those described in the first embodiment of the present disclosure.

[0080] Although the preferred embodiments have been described in detail above, the present disclosure is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope described in the claims.

[0081] The numbers such as ordinal numbers and quantities used in the description of the embodiments are all exemplified for specifically explaining the technology of the present disclosure, and the present disclosure is not limited to the exemplified numbers. In addition, the connection relationship between the components is exemplified for specifically explaining the technology of the present disclosure, and the connection relationship for realizing the functions of the present disclosure is not limited thereto.

[0082] The division of the blocks in the functional block diagram is an example, and a plurality of blocks may be realized as one block, one block may be divided into a plurality of blocks, or some functions may be transferred to other blocks. In addition, the functions of a plurality of blocks having similar functions may be processed by a single piece of hardware or software in parallel or in time division. Further, some or all of the functions may be distributed among a plurality of computers.

[0083] Aspects of the present disclosure are, for example, as follows. <1> A laser processing apparatus, comprising: a laser light source; an optical scanning unit that scans laser light emitted from the laser light source on the surface of an object; a first signal that is a continuous signal having a first period; and a second signal that is a continuous signal having a second period shorter than the first period, wherein a control unit controls the emission timing of the laser light by the laser light source based on the first signal and the second signal, so as to control the interval between the laser light irradiated on the surface of the object. <2> Corresponding information regarding the relationship between the timing of the first signal with respect to a reference signal and the number of signals of the second signal corresponding to the time shift from the timing of the first signal is predetermined. The control unit, based on the timing of the first signal with respect to the reference signal, causes the laser light source to emit the laser light at a timing shifted from the timing of the first signal according to the number of signals of the second signal obtained by referring to the corresponding information. The laser processing apparatus according to <1>. <3> The laser processing apparatus according to <2>, further comprising a storage unit that stores the corresponding information. <4> The laser processing apparatus according to any one of <1> to <3>, wherein the second signal is a clock signal. <5> The laser processing apparatus according to any one of <1> to <4>, wherein the length of the second period is 1 / 10 or less of the length of the first period. <6> The scanning region of the laser light on the surface of the object includes a first region where the scanning of the laser light is accelerated, a second region where the scanning speed of the laser light is constant, and a third region where the scanning of the laser light is decelerated. In the second region, the control unit causes the laser light source to emit the laser light based on the first signal, and in the first region and the third region, the control unit causes the laser light source to emit the laser light based on the first signal and the second signal. The laser processing apparatus according to any one of <1> to <5>. <7> The scanning region of the laser beam on the surface of the object includes a first region where the scanning of the laser beam is accelerated, a second region where the scanning speed of the laser beam is constant, and a third region where the scanning of the laser beam is decelerated. The control unit causes the laser light source to emit the laser beam based on the first signal and the second signal in each of the first region, the second region, and the third region. The laser processing apparatus according to any one of <1> to <5> above. <8> The control unit controls the emission of the laser beam by the laser light source further based on image data. The laser processing apparatus according to any one of <1> to <7> above. <9> The optical scanning unit can scan the laser beam in each of a first direction and a second direction opposite to the first direction. The laser processing apparatus according to any one of <1> to <8> above. <10> The optical scanning unit can scan the laser beam in each of a first direction and a second direction opposite to the first direction. The correspondence information referred to in the scanning in the first direction is first correspondence information, and the correspondence information referred to in the scanning in the second direction is second correspondence information different from the first correspondence information. The laser processing apparatus according to <2> or <3> above. <11> The object is a container configured to include a resin. The laser processing apparatus according to any one of <1> to <10> above. <12> The object is a PET bottle. The laser processing apparatus according to any one of <1> to <11> above. <13> A laser processing system having the laser processing apparatus according to any one of <1> to <12> above and a transport mechanism for transporting the object, wherein the optical scanning unit scans the laser beam on at least one of the surface of the object being transported by the transport mechanism and the surface of the object that has stopped after being transported by the transport mechanism.

Explanation of Reference Signs

[0084] 1 Laser light source 2 Optical Scanning Unit 20 Reflective Surface 21 Swing Axis 22 Swing Direction 221 Forward Swing Direction 3 Control Unit 31 Second Signal Generation Unit 32 Storage Unit 320 Corresponding Information 33 Decision Unit 34 Injection Control Unit 35 Output Unit 4 Retroreflector 100 Laser Processing Device 200 Object A Scanning Area A1 First Area A2 Second Area A3 Third Area B System Bus Cr Direction Switching Period Dr Injection Control Signal Ga, Gb Graph Im Image Data L Laser Light N Number of Signals P1 First Period P2 Second Period S1 First Signal S2 Second Signal Sg Reference Signal Ta, Tb Scanning Period Ta1, Tb1 First Period Ta2, Tb2 Second Period Ta3, Tb3 Third Period X1 First Direction X2 Second Direction δ1, δ2 Time Shift Δ Interval

Prior Art Documents

Patent Documents

[0085]

Patent Document 1

Claims

1. a laser light source that irradiates the surface of an object; an optical scanning unit that scans the laser light emitted from the laser light source on the surface of the object; a control unit that can control the interval between the laser lights irradiated on the surface of the object by controlling the emission timing of the laser light by the laser light source based on a first signal that is a continuous signal having a first period and a second signal that is a continuous signal having a second period shorter than the first period; a laser processing apparatus.

2. Corresponding information regarding the relationship between the timing of the first signal with respect to a reference signal and the number of signals of the second signal corresponding to the time shift from the timing of the first signal is predetermined, The control unit emits the laser light to the laser light source at a timing shifted from the timing of the first signal according to the number of signals of the second signal obtained by referring to the corresponding information based on the timing of the first signal with respect to the reference signal. The laser processing apparatus according to claim 1.

3. The laser processing apparatus according to claim 2, further comprising a storage unit that stores the corresponding information.

4. The second signal is a clock signal. The laser processing apparatus according to claim 1 or claim 2.

5. The length of the second period is 1 / 10 or less of the length of the first period. The laser processing apparatus according to claim 1 or claim 2.

6. The scanning area of the laser light on the surface of the object is a first area where the scanning of the laser light is accelerated; a second area where the scanning speed of the laser light is constant; a third area where the scanning of the laser light is decelerated; and includes, In the second area, the control unit emits the laser light to the laser light source based on the first signal, and in the first area and the third area, the control unit emits the laser light to the laser light source based on the first signal and the second signal. The laser processing apparatus according to claim 1 or claim 2.

7. The scanning area of the laser light on the surface of the object is a first area where the scanning of the laser light is accelerated; a second area where the scanning speed of the laser light is constant; a third area where the scanning of the laser light is decelerated; and includes, The laser processing apparatus according to claim 1 or claim 2, wherein the control unit causes the laser light source to emit the laser light based on the first signal and the second signal in each of the first region, the second region, and the third region.

8. The laser processing apparatus according to claim 1 or claim 2, wherein the control unit further controls the emission of the laser light by the laser light source based on the image data.

9. The laser processing apparatus according to claim 1 or claim 2, wherein the optical scanning unit is capable of scanning the laser light in each of a first direction and a second direction opposite to the first direction.

10. The optical scanning unit is capable of scanning the laser light in each of a first direction and a second direction opposite to the first direction, the corresponding information referred to in the scanning in the first direction is first corresponding information, and the corresponding information referred to in the scanning in the second direction is second corresponding information different from the first corresponding information. The laser processing apparatus according to claim 2.

11. The laser processing apparatus according to claim 1 or claim 2, wherein the object is a container configured to include a resin.

12. The laser processing apparatus according to claim 1 or claim 2, wherein the object is a PET bottle.

13. A laser processing apparatus according to claim 1 or claim 2, and a transport mechanism for transporting the object, wherein the optical scanning unit scans the laser light on at least one of the surface of the object being transported by the transport mechanism and the surface of the object that has stopped after being transported by the transport mechanism. A laser processing system.

Images