JP2024076965A - Laser processing method and laser processing device - Google Patents

Abstract

[Problem] To provide a laser processing method that can suppress the occurrence of defective products when at least a first object and a second object are transported in that order and the objects are processed with laser light. [Solution] The laser processing method according to the present invention is a method for processing a plurality of objects with laser light by transporting a first object and a second object in that order, and includes a first detection step for detecting that the first object has been transported to a predetermined position when laser processing the first object, a second detection step for detecting that the second object has been transported to the predetermined position when laser processing the second object, a determination step for determining a processing start position for the second object, and an irradiation step for scanning the laser light at the determined processing start position for the second object within the effective diameter of a focusing means and irradiating the laser light to a processing end position. [Selected Figure] None

Description

The present invention relates to a laser processing method and a laser processing device.

Patent Document 1 discloses a method for processing a workpiece that can process the workpiece even when the transport speed of the workpiece is different. However, Patent Document 1 does not take into consideration highly accurate processing of the workpiece, and when transporting at least a first object and a second object in that order and processing the objects with laser light, there are cases where a sufficient time cannot be secured between the end of processing the first object and the start of processing the second object, which may result in defectively processed products.

One aspect of the present invention aims to provide a laser processing method that can suppress the occurrence of defective products when conveying at least a first object and a second object in that order and processing the objects with laser light.

One aspect of the present invention is
A laser processing method for processing a plurality of objects including at least a first object and a second object by conveying the first object and the second object in this order and processing the plurality of objects including the first object and the second object with a laser beam, comprising:
a first detection step of detecting, by a detection means, that the first object has been transported to a predetermined position when the first object is to be laser processed;
a second detection step of detecting, by the detection means, that the second object has been transported to the predetermined position when the second object is to be laser processed;
a determination step of determining a processing start position of the second object based on a time from a time when the first object is detected in the first detection step to a time when the second object is detected in the second detection step and a transport speed of the first object and the second object;
an irradiation step of scanning the laser light at the processing start position of the second object determined in the determination step within an effective diameter of a focusing means, and irradiating the laser light to a processing end position;
A laser processing method comprising the steps of:

Another aspect of the present invention is
A laser processing apparatus that conveys at least a first object and a second object in this order and processes a plurality of objects including the first object and the second object with a laser beam,
A conveying means for conveying at least the first object and the second object in that order;
a processing means for processing the object with the laser light;
A detection means for detecting the object;
A determination means for determining a processing start position of the second object;
having
the detection means detects that the first object has been transported to a predetermined position when the first object is to be laser processed, and detects that the second object has been transported to the predetermined position when the second object is to be processed with the laser light from a processing start position to a processing end position,
the determining means determines the processing start position of the second object based on a time from when the first object is detected by the detecting means to when the second object is detected and a transport speed of the first object and the second object;
The processing means is a laser processing device that scans the laser light at the processing start position of the second object determined by the determination means within the effective diameter of the focusing means, and irradiates the laser light up to the processing end position.

According to one aspect of the present invention, it is possible to suppress the occurrence of defective products when processing the objects with laser light by conveying at least a first object and then a second object in that order.

FIG. 1 is a schematic diagram showing an example of a laser processing apparatus according to a first embodiment. FIG. 2 is a schematic diagram showing an example of a focusing means in a laser processing apparatus. FIG. 3 is an explanatory diagram showing an example of a change in property of a container body which is an object. FIG. 4 is a schematic diagram showing an example of a processing start position of a first object in the laser processing method according to the first embodiment. FIG. 5 is a schematic diagram showing an example of a state after machining of the first object. FIG. 6 is a schematic diagram showing conditions for the distance L0 from the processing start position to the processing end position in the laser processing method according to the first embodiment. FIG. 7 is a flowchart showing an example of a process flow in the laser processing method according to the second embodiment. FIG. 8 is a schematic diagram showing an example of a processed state in the laser processing method according to the second embodiment. FIG. 9 is a schematic diagram showing another example of a processed state in the laser processing method according to the second embodiment. FIG. 10 is a schematic diagram showing another example of a processed state in the laser processing method according to the second embodiment. FIG. 11 is a schematic view showing another example of a processed state in the laser processing method according to the second embodiment. FIG. 12 is a schematic diagram showing an example of the relationship between the lens effective diameter L3 and the minimum value L1min in the laser processing method according to the second embodiment. FIG. 13 is a schematic diagram showing an example of the relationship between the lens effective diameter L3 and the maximum value L1max in the laser processing method according to the second embodiment. FIG. 14 is a schematic diagram showing an example of the arrangement of objects when a plurality of laser devices are arranged in the transport direction in the laser processing method according to the second embodiment. FIG. 15 is a schematic diagram showing an example of an arrangement of objects in the laser processing method according to the third embodiment using a plurality of laser devices.

The following is a detailed description of the embodiments of the present invention. In this specification, unless otherwise specified, the numerical range "to" means that the numerical range includes the numerical range before and after it as the lower and upper limits.

(Laser processing method and laser processing device)
A laser processing method according to an embodiment of the present invention is a laser processing method in which at least a first object and a second object are transported in this order, and a plurality of objects including at least the first object and the second object are processed with a laser beam,
a first detection step of detecting, by a detection means, that the first object has been transported to a predetermined position when the first object is to be laser processed;
a second detection step of detecting, by the detection means, that the second object has been transported to the predetermined position when the second object is to be laser processed;
a determination step of determining a processing start position of the second object based on a time from a time when the first object is detected in the first detection step to a time when the second object is detected in the second detection step and a transport speed of the first object and the second object;
an irradiation step of scanning the laser light at the processing start position of the second object determined in the determination step within an effective diameter of a focusing means, and irradiating the laser light to the processing end position;
including.

A laser processing apparatus according to an embodiment of the present invention is a laser processing apparatus that conveys at least a first object and a second object in this order and processes a plurality of objects including at least the first object and the second object with a laser beam,
A conveying means for conveying at least the first object and the second object in that order;
a processing means for processing the object with the laser light;
A detection means for detecting the object;
A determination means for determining a processing start position of the second object;
having
the detection means detects that the first object has been transported to a predetermined position when the first object is to be laser processed, and detects that the second object has been transported to the predetermined position when the second object is to be processed with the laser light from a processing start position to a processing end position,
the determining means determines the processing start position of the second object based on a time from when the first object is detected by the detecting means to when the second object is detected and a transport speed of the first object and the second object;
The processing means scans the laser light at the processing start position of the second object determined by the determination means within an effective diameter of the focusing means, and irradiates the laser light up to the processing end position.

In one embodiment of the laser processing method, when a first object is laser processed, a first detection step is performed by a detection means to detect that the first object has been transported to a predetermined position, and when a second object is laser processed, a second detection step is performed by a detection means to detect the second object, a determination step is performed by a determination step of a processing start position of the second object based on the time from when the first object is detected in the first detection step to when the second object is detected in the second detection step and the transport speed of the first object and the second object, and an irradiation step is performed by scanning the laser light to the processing start position of the second object within the effective diameter of the focusing means and irradiating the laser light to the processing end position. As a result, according to the laser processing method of one embodiment, even if there is a variation in the distance L1 between the first object and the second object (hereinafter sometimes referred to as "distance L1"), the variation in the distance L1 can be absorbed and laser processing can be performed without being affected by the variation in the distance L1, thereby suppressing the occurrence of defective products. Furthermore, to absorb the variation in distance L1, it is necessary to increase the effective lens diameter by the amount of absorption, but even in this case, laser processing can be performed within the effective lens diameter without being affected by the variation in distance L1, so the non-processing time becomes constant, and productivity can be significantly improved.

Note that distance L1 represents the shortest distance between the centers of adjacent first and second objects.

In the prior art, when the focusing means is a lens, there are various constraints such as the focal length of the lens, the effective lens diameter, and the beam diameter, and even if at least the first object and the second object are transported in this order and there is variation in the distance L1, it has not been possible to perform continuous laser processing while following the transported object without being affected by the variation in the distance L1.

In general, pulse laser processing is defined by the following formulas (1) and (2): The pulse energy E per pulse is the value obtained by dividing the average output P by the repetition frequency ν, and the fluence F is the value obtained by dividing the pulse energy E by the beam spot diameter area S.
P = E · v ... Formula (1)
(In formula (1), P represents the average output (unit: W), E represents the pulse energy (unit: J), and ν represents the repetition frequency (unit: Hz).)

F = E / S ... Formula (2)
(In formula (2), F represents fluence (unit: J/cm ² ), S represents beam spot diameter area (unit: cm ² ), and E represents pulse energy (unit: J).)

The parameters used in laser processing are defined by the laser specifications used and the beam spot diameter during processing using formulas (1) and (2).

The pulse width represents the time during which one pulse of laser light is irradiated onto the target. With a pulse width on the order of nanoseconds (1 x ^10-9 seconds), laser processing is performed by thermal denaturation according to the absorption spectrum of the target. With a pulse width on the order of picoseconds ( ^10-12 seconds) or less, in addition to thermal denaturation of the target, a phenomenon occurs in which the state of electrons and atoms transitions to a higher energy level due to the simultaneous absorption of multiple photons at 1/2 to 1/3 of the wavelength of the laser light used. As a result, the target in a solid state is sublimated without going through a molten state, and processing marks can be obtained.

The target machining diameter d depends on the incident beam radius ω ₀ and the pulse energy E of the irradiated laser according to the following formula (3).
d ² =2·ω ₀ ² ·ln(F/Fth) ...Equation (3)
(In formula (3), d represents the processing diameter [cm ² ], ω ₀ represents the incident beam radius [unit: cm ² ], F represents the fluence [unit: J/cm ² ], and Fth represents the processing threshold [unit: J/cm ² ].)

In one embodiment of the laser processing method, the laser processing is performed while following the object being transported. Therefore, the laser light needs to be irradiated at a processing distance where the object is laser processed while being transported.

There is a trade-off between the irradiation range of the laser light (lens effective diameter) and the lens focal length, so for example, in terms of lens design, it is impossible to have a wide lens effective diameter in a lens with a short focal length.

Furthermore, one of the required specifications for laser processing is resolution. To satisfy the required resolution, a processing diameter d equivalent to the resolution is required. For example, if the resolution is 600 dpi, the processing diameter d is 42.3 μm. To obtain the required processing diameter d, the required incident beam radius ω ₀ is calculated from formula (3) and the lens focal length is determined. When the lens focal length is determined, the lens effective diameter L3 is also determined.

In one embodiment of the laser processing method, when a first object is laser processed, it is necessary to detect that the first object has been transported to a predetermined position, and when a second object is laser processed, the second object is detected by a detection means, the processing start position of the second object is determined from the time from detection to detection of the second object and the transport speed of the first object and the second object, and the laser light is scanned to the processing start position of the second object within the effective diameter of the focusing means, and the laser light is irradiated to the processing end position.

In addition, in the laser processing method according to one embodiment, when processing a first object from the processing start position to the processing end position with a laser beam, it is preferable that the distance L0 (unit: mm) from the processing start position to the processing end position of the first object is equal to or less than the distance L1 (hereinafter sometimes referred to as "distance L0") (unit: mm) between the first object and the second object (see the following formula (i)), and that the distance L0 is less than the lens effective diameter L3 (see the following formula (ii)). In the laser processing method according to one embodiment, by satisfying the following formulas (i) and (ii), it is possible to sufficiently secure the time from the processing end point of the first object to the processing start point of the second object, and it is possible to appropriately correct the scanning time of the scanning means, the position information of the object, and the posture information of the object, and the like, and to suppress the occurrence of defective processed products.
L0≦L1 (i)
L0<L3 (ii)

Note that distance L0 represents the shortest distance between the center of the first object at the processing start position and the center of the first object at the processing end position.

It is also preferable to satisfy the lens effective diameter L3 with a lens of the desired focal length.

In one embodiment, the distance L1 is the average value L1ave of the distances of multiple objects, and the average value L1ave is an average value including at least the minimum value L1min (unit: mm) of the distance L1 and the maximum value L1max (unit: mm) of the distance L1.

In one embodiment, it is preferable that the minimum value L1min and the distance L0 satisfy the following formula (I).
L0≦L1min (I)

When formula (I) above is satisfied, distance L1 is always greater than distance L0, so that the time from the end of processing the first object to the start of processing the second object can be sufficiently secured, making it possible to appropriately correct the scanning time of the scanning means, the position information of the object, and the attitude information of the object, etc., thereby reducing the occurrence of defectively processed products.

In one embodiment, it is preferable that the minimum value L1min, the distance L0, and the maximum value L1max satisfy the following formula (II).
L1min≦L0≦L1max (II)

When formula (II) above is satisfied, the variation in the multiple objects creates a condition L1 that is smaller than the distance L0. With conventional methods, the second object passes the processing start position and cannot be processed, resulting in reduced productivity. However, with the laser processing method according to one embodiment, the detection means can measure the distance between the first object and the second object, and the position of the second object can be calculated from the known conveying speed when processing of the first object is completed. Therefore, even when a distance L1 that includes variation occurs, processing is possible and the occurrence of defective products can be suppressed.

In one embodiment, when processing a first object using multiple laser beams from the processing start position to the processing end position, it is preferable that the distance L0 (unit: mm) and the distance L1 (unit: mm) satisfy the following formula (III).
L0≦N·L1 (III)
(In the formula, N represents the number of laser beams and is an integer of 2 or more.)

When formula (III) above is satisfied, even when multiple laser beams are used, it is possible to ensure sufficient time between the end of processing of the first object and the start of processing of the second object, and it is possible to appropriately correct the scanning time of the scanning means, the position information of the object, and the attitude information of the object, thereby reducing the occurrence of defectively processed products.

＜Target Object＞
The object is not particularly limited and can be appropriately selected depending on the purpose, but is preferably a container. The container has a container body and a cap that seals the contents inside the container body.

- Container body -
The container body is not particularly limited in terms of material, shape, size, structure, color, etc., and can be appropriately selected depending on the purpose.

The material of the container body is not particularly limited and can be appropriately selected depending on the purpose. Examples include resin, glass, etc. Among these, transparent resin or transparent glass is more preferable, and transparent resin is particularly preferable.

Examples of resins that can be used for the container body include polyvinyl alcohol (PVA), polybutylene adipate/terephthalate (PBAT), polyethylene terephthalate succinate, polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polyvinyl chloride (PVC), polystyrene (PS), polyurethane, epoxy, bio-polybutylene succinate (PBS), polylactic acid blend (PBAT), starch blend polyester resin, polybutylene terephthalate succinate, polylactic acid (PLA), polyhydroxybutyrate/hydroxyhexanoate (PHBH), polyhydroxyalkanoic acid (PHA), Bio-PET 30, Bio-polyamide (PA) 610, 410, 510, Bio-PA 1012, 10T, Bio-PA 11T, MXD 10, Bio-polycarbonate, Bio-polyurethane, Bio-PE, Bio-PET 100, Bio-PA 11, Bio-PA 1010, etc. These may be used alone or in combination of two or more. Among these, biodegradable resins such as polyvinyl alcohol, polybutylene adipate/terephthalate, and polyethylene terephthalate succinate are preferred from the viewpoint of environmental load.

The shape of the container body is not particularly limited and can be appropriately selected depending on the purpose. Examples include a cylindrical shape, a square prism shape, a box shape, a cone shape, a bottle shape, and the like. Among these, a cylindrical shape is preferred from the viewpoint of marking accuracy. When the container body has a bottle-like shape, the bottle-like container body may have a mouth, a shoulder connected to the mouth, a body connected to the shoulder, and a bottom connected to the body.

There are no particular limitations on the size of the container body, and it can be selected appropriately depending on the use of the container.

There are no particular limitations on the structure of the container body and it can be selected appropriately depending on the purpose. For example, it can be a single-layer structure or a multi-layer structure.

The color of the container body may be, for example, colorless and transparent, colored and transparent, colored and opaque, etc. Of these, colorless and transparent is preferred.

-cap-
The material, shape, size, structure, color, etc. of the cap are not particularly limited and may be appropriately selected depending on the purpose.

The material of the cap is not particularly limited and can be selected appropriately depending on the purpose. Examples include resin, glass, metal, ceramics, etc. Among these, resin is preferred from the viewpoint of moldability.

The resin for the cap can be the same as that for the body of the container.

There are no particular limitations on the shape and size of the cap, so long as it is capable of sealing (closing) the opening of the container body, and it can be selected appropriately depending on the purpose.

There are no particular limitations on the structure of the cap and it can be selected appropriately depending on the purpose, but for example, it is preferable for the cap to have a first part that separates from the container body when opened and a second part that remains on the container body.

It is preferable that the side of the first part has an uneven surface to prevent the hand from slipping when opening the package. It is preferable that the side of the second part does not have an uneven surface and has a flat surface.

The cap color can be, for example, colored and opaque, colored and transparent, etc. Among these, colored and opaque is preferred from the standpoint of image readability.

-Contents-
Examples of the contained object include liquid, gas, granular solids, and the like.

Examples of liquids include water, tea, coffee, black tea, soft drinks, liquid detergents, liquid cosmetics, etc. When the contents are liquid beverages, they are often transparent, white, black, brown, yellow, or other colors.

Examples of gases include oxygen, hydrogen, nitrogen, etc.

Examples of granular solids include pieces or particles of fruit pulp, vegetables, nata de coco, tapioca, jelly, konjac, etc., powder detergents, cosmetics, etc.

<Transportation process and transport means>
The conveying step is a step of conveying at least a first object and a second object in this order, and is performed by a conveying means.

Examples of the transport means include a belt conveyor.

There are no particular limitations on the speed at which the object is transported by the transport means, and it can be selected appropriately depending on the purpose.

<Decision process and decision means>
The determining step is a step of determining the processing start position of the second object from the time from the detection of the first object to the detection of the second object in the detecting step and the transport speed of the first object and the second object, and is performed by a determining means. As a result, even if the distance L1 varies, the variation in the distance L1 can be absorbed by the determining step, and the occurrence of defective processed products can be suppressed.

<Detection process and detection means>
The detection step is a step of detecting the position of an object, and is performed by a detection means.

When a first object is to be laser processed, the detection means detects that the first object has been transported to a predetermined position, and when a second object is to be laser processed, the detection means detects that the second object has been transported to a predetermined position.

The detection means is equipped with a light-emitting unit and a light-receiving unit.

The light projecting section may be of either a transmissive or reflective type.

The type of detection method is not important.

As a detection means, various means can be used depending on the transparency or shape of the object. Also, detection means may be used in combination.

The detection process includes a first detection process and a second detection process.

In the first detection step, when a first object is to be laser processed, the detection means detects that the first object has been transported to a predetermined position.

In the second detection step, when a second object is to be laser processed, the detection means detects that the second object has been transported to a predetermined position.

<Processing steps and processing means>
The processing step is a step of processing an object with laser light, and is performed by a processing means.

The processing means includes, for example, a laser light source, a scanning means, and a focusing means.

The laser light source is a light source that emits laser light. The laser light source is included in the laser device. The laser light source is not particularly limited and can be appropriately selected depending on the purpose, and examples of the laser light source include an excimer laser, a Nd:YAG laser, a Nd: _YVO4 laser, and a semiconductor laser.

The laser light source can repeatedly output short pulses of laser light with a constant peak intensity.

The short-pulse laser light is composed of a pulse train including a plurality of pulses with a constant peak intensity. The short-pulse laser light means a light having a pulse width of nanoseconds (1×10 ⁻⁹ seconds) or less. The pulse width of the short-pulse laser light is preferably on the order of femtoseconds (10 ⁻¹⁵ seconds) to picoseconds (10 ⁻¹² seconds). The repetition frequency of the short-pulse laser light is preferably 10 kHz to 1 MHz, and more preferably 500 kHz to 1 MHz.

<Scanning Means>
The scanning means is a means for scanning the laser light incident from the laser light source in a predetermined direction. Examples of the scanning means include a rotating polygonal mirror such as a galvanometer mirror, a polygon mirror, a MEMS (Micro Electro Mechanical System) mirror, and a polygon scanner.

<Light Concentration Means>
The focusing means focuses the laser light. For example, a lens or the like can be used as the focusing means, which keeps the scanning speed of the laser light scanned by the scanning means constant and converges the laser light at least at any predetermined position on the target object. Examples of such lenses include an fθ lens and an arc sine lens.

<Irradiation step>
The irradiation step is a step of scanning the laser light within the effective diameter of the focusing means at the processing start position of the second object determined in the determination step, and irradiating the laser light to the processing end position. The effective diameter of the focusing means means the irradiation range of the laser light, and is the diameter of the focusing lens through which the laser light can pass. If simplified to a single lens, the diameter (= maximum diameter) of the single lens becomes the effective diameter.

<Other measures>
The other means is not particularly limited and can be appropriately selected depending on the purpose. For example, a control means and the like can be mentioned.

The control means is not particularly limited as long as it can control the movement of each of the means, and can be appropriately selected depending on the purpose. For example, devices such as a sequencer and a computer can be mentioned.

Here, a laser processing method and a laser processing device according to one embodiment will be described in detail with reference to the drawings. Note that in each drawing, the same components are given the same reference numerals, and duplicated explanations may be omitted. Furthermore, the number, position, shape, etc. of the components described below are not limited to this embodiment, and may be of any number, position, shape, etc. that is preferable for implementing the laser processing method and laser processing device according to one embodiment.

First Embodiment
Fig. 1 is a schematic diagram showing an example of a laser processing apparatus according to the first embodiment. As shown in Fig. 1, the laser processing apparatus 10 includes, as an optical system, a laser device 11, a beam expander 12, a scanning means 13, an irradiation control means 14, a focusing means 15, and a detection means 16, and irradiates an object 18 with a laser beam 20.

In FIG. 1, the conveying direction of the object 18 is the X direction, and the direction perpendicular to the conveying direction of the object 18 and different from the traveling direction of the laser light 20 is the Y direction. FIG. 1 shows a state in which the object 18 is conveyed downstream in the conveying direction (X direction) at a conveying speed V. The arrows in FIG. 1 represent the optical system and the conveying direction of the object 18 when the laser light 20 is irradiated to the object 18.

The object 18 is irradiated with the laser light 20 emitted from the laser device 11 while being transported.

There are no particular limitations on the object 18 as long as it is irradiated with the laser light 20, and it can be selected appropriately depending on the purpose, but it is preferable that it is a container, for example. If the object 18 is a resin container, it is preferable that the laser light 20 causes a change in the properties of the container body.

The laser device 11 is a device that emits laser light 20. The laser device 11 emits laser light 20 with an output (light intensity) suitable for changing at least one of the properties of the surface and the interior of the base material of the object 18 irradiated with the laser light 20.

There are no particular limitations on the type of laser light 20, but from the standpoint of intensity, a pulsed laser is preferred.

The laser device 11 can control the emission of the laser light 20 by turning it on or off, controlling the emission frequency, and controlling the light intensity. As an example of the laser device 11, for example, a laser device having a wavelength of 355 nm, a pulse width of the laser light 20 of 10 picoseconds, and an average output of 30 W to 50 W can be used.

The diameter of the laser light 20 in the area of the object 18 where the properties of the base material are to be changed is preferably 1 μm to 200 μm.

In FIG. 1, one laser device 11 is shown, but multiple laser devices 11 may be provided. When multiple laser devices 11 are used, each laser device 11 may be independently controlled to be turned on or off, to have an emission frequency that is equal to or smaller than the light intensity, and the like.

The beam expander 12 expands the laser light. The parallel laser light 20 emitted from the laser device 11 has its diameter expanded by the beam expander 12 and enters the scanning means 13.

The scanning means 13 scans the laser light 20. The scanning means 13 has a mirror 13a and a mirror 13b. The mirrors 13a and 13b have a function of changing the reflection angle by a driving unit such as a motor.

Mirror 13a is a scanning mirror that scans the incident laser light 20 in the X direction by changing its reflection angle. Mirror 13a can be a galvanometer mirror, a polygon mirror, a MEMS (Micro Electro Mechanical System) mirror, or the like.

In this embodiment, the mirrors 13a and 13b perform one-dimensional scanning of the laser light 20 in the X direction, but the present invention is not limited to this. For example, the mirrors 13a and 13b may be scanning mirrors that change the reflection angle in two orthogonal directions to perform two-dimensional scanning of the laser light 20 in the X and Y directions.

The laser light 20 scanned by mirror 13a and mirror 13b is irradiated onto at least one of the surface or the interior of the substrate of the object 18.

The irradiation control means 14 outputs a signal to the laser device 11 to control the laser output, and outputs a signal to the mirror 13b to scan the laser light 20.

The irradiation control means 14 is connected to the light receiving unit 16b, which is part of the detection means 16, and can control the light receiving unit 16b and perform calculation and storage processing.

The focusing means 15 focuses the laser light. The focusing means 15 is a lens that keeps the scanning speed of the laser light 20 scanned by the mirrors 13a and 13b constant and converges the laser light 20 to a predetermined position on at least one of the surface and the interior of the substrate of the object 18. For example, an fθ lens, an arc sine lens, or other lens that keeps the scanning speed constant can be used as the focusing means 15. The focusing means 15 may be composed of a combination of multiple lenses.

It is preferable that the focusing means 15 is positioned so that the beam spot diameter of the laser light 20 is minimized in the area in the object 18 where the properties of the base material are to be changed.

Figure 2 is a schematic diagram showing an example of the focusing means 15 in the laser processing device 10. Regarding the relationship between the lens effective diameter L3 and the scanning of the laser light 20, the laser processing of the object 18 is performed within the lens effective diameter L3 of the focusing means 15. That is, the laser light 20 is scanned by the mirror 13b within the range of the dashed line indicating the lens effective diameter L3 of the focusing means, irradiating the object 18 with the laser light, and the laser processing of the object 18 is performed.

To obtain the energy required for laser processing, the smaller the beam diameter of the irradiated laser light 20, the more the energy is concentrated, making laser processing easier. On the other hand, the larger the beam diameter of the laser light 20, the more difficult it is to laser process. Since the beam diameter changes depending on the lens focal length, the longer the lens focal length, the wider the effective lens diameter. On the other hand, the shorter the lens focal length, the narrower the effective lens diameter. Therefore, since there is a trade-off between the effective lens diameter and the lens focal length, it is important to design while achieving a balance between the lens focal length and the effective lens diameter.

As shown in FIG. 1, the detection means 16 detects the position of the target object 18. The detection means 16 has a light projecting unit 16a and a light receiving unit 16b. The light projecting unit 16a and the light receiving unit 16b detect the position of the target object 18 upstream of the laser device 11 in the conveying direction.

The detection means 16 may be of a transmission type or a reflection type, and there is no particular limit to the type of detection method used by the detection means 16. In the case of a reflection type, the detection means 16 projects light from the light-projecting unit 16a onto the object 18. The detection means 16 detects the position of the object 18 based on the position at the light-receiving unit 16b and the time it takes for the light to be received. In the case of a transmission type, the detection means 16 projects light from the light-projecting unit 16a onto the object 18 and receives the transmitted light at the light-receiving unit 16b to detect the position of the object.

The installation positions of the various sensors and the transport location and transport speed V of the target object 18 are known parameters, so the timing of irradiation with the laser light 20 can be determined from these existing parameters.

In the case of a container body which is the object 18, an example of the change in the properties of the object 18 when the object 18 is laser processed will be described. FIG. 3 is an explanatory diagram showing an example of the change in the properties of the container body which is the object 18. As shown in FIG. 3(a), a part of the surface of the container body which is the object 18 is irradiated with a laser beam 20 to evaporate a part of the surface of the container body, thereby forming a concave shape on the surface of the container body. As shown in FIG. 3(b), a part of the surface of the container body which is the object 18 is irradiated with a laser beam 20 to melt a part of the surface of the container body, thereby forming a concave shape on the surface of the container body, and the peripheral part of the concave is formed in a shape that is more raised than that in FIG. 3(a). As shown in FIG. 3(c), a part of the surface of the container body which is the object is irradiated with a laser beam 20 to crystallize a part of the surface of the container body, thereby changing a part of the surface of the container body to a crystallized state. As shown in FIG. 3(d), a part of the surface of the container body which is the object is irradiated with a laser beam 20 to generate bubbles inside or on the surface of the container body, thereby changing a part of the inside or surface near the surface of the container body to a foamed state. As shown in (a) to (d) of FIG. 3, the properties of the container body can be changed by irradiating the target container body with laser light 20.

In this way, by changing the shape of a portion of the surface of the container body (the target object) or by changing the properties of the container body, such as by crystallizing a portion of the surface of the container body or forming bubbles inside the container body, it is possible to bring about a change in the properties of the surface or inside of the container body.

As shown in Figures 3(a) and (b), one method of forming a recessed shape by evaporating a part of the surface of the container body, which is the object, is to irradiate it with a pulsed laser having a wavelength of 355 nm to 1,064 nm and a pulse width of 10 fs to 500 ns. This causes the part of the surface of the container body irradiated with the laser light to evaporate, forming a minute recess in that part of the surface of the container body.

It is also possible to form a recess in a part of the surface of the container body by irradiating a part of the surface of the container body with a CW (Continuous Wave) laser light having a wavelength of 355 nm to 1,064 nm to melt the part. In addition, by continuing to irradiate the laser light even after the part of the surface of the container body has melted, the inside and surface of the container body can be foamed and clouded, as shown in FIG. 3(d).

As shown in Figure 3(c), when part of the surface of the container body is changed to a crystallized state, for example, the container body can be made of polyethylene terephthalate (PET) resin, and a CW laser beam with a wavelength of 355 nm to 1,064 nm can be irradiated to raise the temperature of the container body in one go, and then the laser power can be reduced to allow it to gradually cool. This allows part of the PET resin on the surface of the container body to be brought into a crystallized state, causing it to become opaque. Note that if the temperature is raised and then the laser beam is turned off to rapidly cool the PET resin, it will become amorphous and transparent.

The change in the properties of the target container body is not limited to those shown in (a) to (d) of FIG. 3. The properties of the container body made of a resin material may be changed by yellowing, oxidation reaction, surface modification, etc.

It is also possible to apply an absorbent (conversion material) that absorbs the irradiated laser light 20 and converts the light energy into thermal energy to the container body in advance, and then perform heating control to form recesses or protrusions in the container body using the thermal energy converted by the absorbent. By forming recesses or protrusions in the container body, letters, symbols, figures, etc. can be expressed.

A laser processing method according to the first embodiment is described below, in which an object 18 is laser-processed using a laser processing device according to the first embodiment shown in FIG. 1. FIG. 4 is a schematic diagram showing the processing start position of a first object in the laser processing method according to the first embodiment. Note that in FIG. 4, of the objects 18 shown in FIG. 1, the first object is referred to as the first object 18a, the second object is referred to as the second object 18b, and the first object 18a and the second object 18b are collectively referred to as the objects 18.

In the first embodiment, when laser processing is performed from the processing start position to the processing end position of the first object 18a, the distance L0 (unit: mm) from the processing start position to the processing end position and the distance L1 (unit: mm) between the first object 18a and the second object 18b satisfy the following formula (i).
L0≦L1 (i)

According to the laser processing method of the first embodiment, the time from the end of processing of the first object 18a to the start of processing of the second object 18b can be sufficiently secured, and the scanning time of the scanning means, the position information of the object 18, and the attitude information of the object 18, etc. can be appropriately corrected, thereby suppressing the occurrence of defectively processed products.

As shown in FIG. 4, the first object 18a and the second object 18b are transported in this order in the transport direction (the direction of the arrow in FIG. 4). In FIG. 4, the solid line indicates the processing start position of the first object 18a, and the dashed line indicates the processing end position of the first object 18a. The two-dot chain line indicates the lens center (this also applies to the other figures below). Distance L0 indicates the distance from the processing start position to the processing end position of the first object 18a, and distance L1 indicates the distance between the first object 18a and the second object 18b.

Figure 5 is a schematic diagram showing an example of the end state of the processing of the first object 18a. As shown in Figure 5, following the first object 18a and the second object 18b, the third object 18c is transported in the transport direction. The distance L1 between the first object 18a and the second object 18b is equal to the distance L1 between the second object 18b and the third object 18c. Figure 5 shows a state in which, at the end of the processing of the first object 18a, the second object 18b is located upstream of the processing start position of the first object 18a. By maintaining this positional relationship, if the object transport speed is V [m/s] and the standby distance is L2 [m], the time from the laser processing of the first object 18a to the laser processing of the second object 18b is the value (L2/V [s]) obtained by dividing the standby distance L2 of the object by the transport speed V of the object.

Furthermore, if the time it takes for the galvanometer mirror to jump from the processing end position to the processing start position is t1 [s], and the time it takes to calculate the processing data according to the detected position and attitude of the object 18 after detecting the position and attitude of the object 18 is t2 [s], then the maximum respective processing times are t1 x L2 [s] and t2 x L2 [s].

The distance L1 between the first object 18a and the second object 18b varies depending on the placement accuracy of the object on the conveying means side. When distance L0>distance L1, the waiting distance L2 is less than 0 (waiting distance L2<0). Since the laser processing device 10 is equipped with the detection means 16, the waiting time L2[s] can be calculated from the time t3[s] between the first object 18a and the second object 18b when passing the detection means 16 and the conveying speed V[m/s]. That is, the waiting distance L2[m] is calculated by multiplying the conveying speed V[m/s] by the time t3[s], and the waiting time L2[s] is calculated by dividing the calculated waiting distance L2[m] by the conveying speed V[m/s].

If the waiting distance L2 is less than 0 (waiting distance L2<0), laser processing is not performed on the object 18, and the object 18 is transported downstream as is, where it is judged to be a rejected product by the downstream inspection device and is not shipped.

Figure 6 is a schematic diagram showing the conditions for the distance L0 from the processing start position to the processing end position in the laser processing method according to the first embodiment. As shown in Figure 6, if the lens effective diameter is L3 and the processing width is W, the maximum distance L0max of the distance L0 is L3 + W (= L3 + 1/2 W + 1/2 W). Since the processing width W is the lens effective diameter L3, the maximum distance L0max is 2 x L3. For example, in the f920 lens, the lens effective diameter L3 is 470 mm, so the maximum distance L0max is 940 mm (= 470 mm x 2). On the other hand, the minimum distance L0min of the distance L0 is 0 mm, since it is a condition for not tracking and processing the target object.

Second Embodiment
The laser processing method of the second embodiment, when laser processing a second object, includes a detection step of detecting the second object by a detection means, a determination step of determining a processing start position of the second object from the time from when the first object is detected in the detection step to when the second object is detected and the transport speeds of the first object and the second object, and an irradiation step of scanning a laser beam to the processing start position of the second object within the effective diameter of a focusing means and irradiating the laser beam to a processing end position, and further includes other steps as necessary.

According to the laser processing method of the second embodiment, even if there is variation in the distance L1, the variation in the distance L1 can be absorbed and laser processing can be performed without being affected by the variation in the distance L1, thereby reducing the occurrence of defective products. Furthermore, when the variation in the distance L1 is absorbed, it is necessary to increase the effective lens diameter by the amount of the absorption, but even in this case, laser processing can be performed within the effective lens diameter without being affected by the variation in the distance L1, so that the non-processing time becomes constant and a significant improvement in productivity can be achieved.

The second embodiment will be described in detail below with reference to the drawings. Note that in the second embodiment, the same configurations as those in the first embodiment already described will be given the same reference numerals and the description thereof will be omitted.

Figure 7 is a flow chart showing an example of the process flow in the laser processing method according to the second embodiment. Below, the process flow of the laser processing method according to the second embodiment executed by the irradiation control means 14 in Figure 1 will be described with reference to Figure 7. The process flow in Figure 7 is executed repeatedly as the first object 18a and the second object 18b are transported in this order, and some steps are executed in parallel.

The following description will focus on the second object 18b, with the first object 18a detected in step S1, the processing start position determined in step S2 from the detected position and transport speed of the first object 18a, and the irradiation process in step S3 and the transport process in step S4 being carried out. Following this processing flow of the first object 18a, the process returns to step S1 to start detecting the second object 18b.

In step S1, when the second object 18b is detected by the detection means 16 of the laser processing device 10, the process proceeds to step S2.

In step S2, the processing start position for the second object 18b is determined based on the time from when the first object 18a is detected to when the second object 18b is detected in the previous flow process and the transport speeds of the first object 18a and the second object 18b, and then the process proceeds to step S3.

In step S3, within the effective diameter of the focusing means in the laser processing device 10, the scanning means scans the laser light 20 at the processing start position of the second object 18b, and irradiates the laser light 20 to the processing end position, and then the process proceeds to step S4.

In step S4, the second object 18b is transported to a predetermined position by the transport means in the laser processing device 10. If there is a third object 18c (see FIG. 8) following the second object 18b, the process returns to step S1 again and continues. If there is no third object 18c following the second object 18b, the process ends.

The flowchart shown in FIG. 7 is preferably implemented as follows. The detection step in step S1 in FIG. 7 includes a first detection step in which the detection means detects that the first object 18a has been transported to a predetermined position when the first object 18a is laser processed, and a second detection step in which the detection means detects that the second object 18b has been transported to a predetermined position when the second object 18b is laser processed. The determination step in step S2 in FIG. 7 determines the processing start position of the second object 18b from the time from when the first object 18a is detected in the first detection step to when the second object 18b is detected in the second detection step, and the transport speeds of the first object 18a and the second object 18b. The irradiation step in step S3 in FIG. 7 scans the laser light 20 at the processing start position of the second object 18b determined in the determination step within the effective diameter of the focusing means, and irradiates the laser light 20 to the processing end position.

In the laser processing method according to the second embodiment, the distance L1 between the first object 18a and the second object 18b is the average value L1ave [m] of the distances of the multiple objects 18, and the average value L1ave is an average value including at least the minimum value L1min [mm] of the distance L1 and the maximum value L1max [mm] of the distance L1.

It is preferable that the minimum value L1min, the distance L0, and the maximum value L1max satisfy the following formula (II).
L1min≦L0≦L1max (II)

As a result, the L1 condition occurs, which is smaller than the distance L0, due to the variation in the multiple objects 18. Conventionally, processing would not be possible because the processing start position of the second object 18b would be passed, resulting in a drop in productivity. However, the laser processing method according to the second embodiment is capable of measuring the distance between the first object 18a and the second object 18b using the detection means 16, and is also capable of calculating the position of the second object 18b at the end of processing of the first object 18a from the known conveying speed. Therefore, the laser processing method according to the second embodiment is capable of processing even when the distance L1, which includes variation, occurs, thereby suppressing the occurrence of defective products.

An example of the processing state in the laser processing method according to the second embodiment is shown in FIG. 8. In (a) and (b) of FIG. 8, a first object 18a and a second object 18b are transported in this order in the direction of the arrows as the transport direction. In FIG. 8, the solid line indicates the processing start position of the first object 18a, the dashed line indicates the processing end position of the first object 18a, and the two-dot chain line indicates the lens center (this also applies to the other figures below).

Figure 8 (a) shows the minimum value L1min indicating the minimum value of the distance between the first object 18a and the second object 18b, and the condition where minimum value L1min≦distance L0.

Figure 8 (b) shows a state in which the third object 18c is transported in the transport direction following the first object 18a and the second object 18b. The minimum value L1min is the minimum value of the distance between the first object 18a and the second object 18b, and L1 indicates the distance between the second object 18b and the third object 18c. When the processing of the first object 18a is completed, the second object 18b is located downstream of the processing start position of the first object 18a (see Figure 8 (b)).

The conveying speed V [m/s] of the conveying means is constant. Therefore, by monitoring the time taken to detect the second object 18b after the position of the first object 18a is detected by the detection means 16, the processing start position of the second object 18b can be identified. In other words, the processing start position of the second object 18b can be identified and the laser irradiation processing can be controlled according to the detection of the first object 18a and the detection of the second object 18b, which is the object to be next irradiated and processed with the laser light 20.

Another example of the processing state in the laser processing method according to the second embodiment is shown in Figs. 9 to 11. As shown in Figs. 9(a) and (b), the laser light 20 is scanned at the processing start position of the identified second object 18b, and the laser light 20 is irradiated onto the second object 18b up to the processing end position to perform laser processing. As a result, the lens effective diameter L3 becomes larger by the amount that the variation in the distance L1 is absorbed, but laser processing is possible within the lens effective diameter L3 without being affected by the variation in the distance L1.

As shown in (a) and (b) of FIG. 10, in (a) and (b) of FIG. 10, the first object 18a and the second object 18b are transported in the transport direction (the direction of the arrow in FIG. 10). FIG. 10(a) shows the condition where the maximum value L1max indicates the maximum distance between the first object 18a and the second object 18b, and the maximum value L1max is equal to or greater than the distance L0 (L0≦L1max).

Figure 10 (b) shows a state in which a third object 18c is transported in the transport direction following the first object 18a and the second object 18b. L1max is the maximum distance between the first object 18a and the second object 18b, and the distance L1 is the distance between the second object 18b and the third object 18c.

When processing of the first object 18a is completed, the second object 18b is located upstream of the processing start position of the first object 18a (see FIG. 10(b)).

Since the conveying speed V [m/s] of the conveying means is constant, the processing start position of the second object 18b can be identified by detecting the detection time of the second object 18b after the detection means 16 detects the first object 18a.

As shown in (a) and (b) of FIG. 11, the laser beam 20 is scanned at the specified processing start position of the second object 18b, and the laser beam 20 is irradiated onto the second object 18b up to the processing end position to perform laser processing. As a result, the lens effective diameter L3 becomes larger by the amount that the variation in the distance L1 is absorbed, but laser processing is possible within the lens effective diameter L3 without being affected by the variation in the distance L1.

12 is a schematic diagram showing an example of the relationship between the lens effective diameter L3 and the minimum value L1min in the laser processing method according to the second embodiment. (a) and (b) of FIG. 12 show the relationship between the lens effective diameter L3 and the minimum value L1min. The minimum value L1min is the diameter D of the object, which is the shortest distance between the adjacent first object 18a and second object 18b, as shown in (a) of FIG. 12. At this time, the distance L0 required to laser process the second object 18b adjacent to the first object 18a is as shown in (b) of FIG. 12, as shown in (4) of FIG. 12. δ in the formula (4) can be calculated from the following formula (5).
L0=δ+L3/2+W/2 ... Formula (4)
δ=D−L0/2 ... Formula (5)

The two-dot chain line in FIG. 12(b) represents the center of the lens. In FIG. 12(b), the first object 18a is at the processing end position. The minimum value L1min means that the first object 18a and the second object 18b are in contact. The distance between the center of the second object 18b and the center of the lens in this state is δ.

From the formulas (4) and (5), the following formula (4)' is derived.
L0=D-L0/2+L3/2+W/2 ... formula (4)'

The lens effective diameter L3 can be expressed as shown in the following formula (6).
L3 = 3 L0 - 2 D - W ... Formula (6)

Figure 13 is a schematic diagram showing an example of the relationship between the lens effective diameter L3 and the maximum value L1max in the laser processing method according to the second embodiment. (a) and (b) of Figure 13 show the relationship between the lens effective diameter L3 and the maximum value L1max of the distance L1 between the first object 18a and the second object 18b. Note that the maximum value L1max is the maximum distance between the second object 18b and the first object 18a when the third object 18c and the second object 18b are adjacent to each other.

13B, the maximum value L1max is reached when the second object 18b is in contact with the third object 18c, and can be expressed as shown in the following formula (7). At the maximum value L1max, the second object 18b and the third object 18c are in contact with each other, and the distance between the first object 18a and the third object 18c is 2·distance L1, and can be expressed as shown in the following formula (8).
L1max=W/2+L3/2+L0/2 ... Formula (7)
2 L1 = D + L1max ... Formula (8)

13B, a lens effective diameter L3 is required that enables writing of the second object 18b. By eliminating the maximum value L1max from the above formula (8), the following formula (9) is derived.
L3 = 4 L1 - L0 - 2 D - W ... Formula (9)

Since the maximum processing width Wmax is equal to the diameter D of the object, the effective lens diameter L3 can be expressed by the following formula (10).
L3 = 4 L1 - L0 - 3 D ... Formula (10)

In (a) and (b) of Figure 13, since distance L1 is greater than distance L0 (distance L1 > distance L0), the required lens effective diameter L3 must satisfy the above formula (10).

For example, the effective lens diameter L3 of an f920 lens is 470 mm, the distance L1 is 160 mm, and the diameter D of the target object is 20 mm, so the distance L0 is 70 mm. As a processing lens, the f920 lens has a large beam diameter. Therefore, when higher-precision laser processing is required, it is preferable to use a lens with a short focal length, such as an f100 lens. However, a lens with a short focal length has a narrow effective lens diameter L3, so the desired laser processing can be performed by changing the distance L1 and the distance L0 within the range that satisfies the above formula (10).

Figure 14 is a diagram showing an example of the arrangement of objects when multiple laser devices are arranged in the transport direction in the laser processing method according to the second embodiment. (a) of Figure 14 shows the respective processing start positions of a first object 18a1 (1-1st) to be laser processed by a first laser device 11 and a second object 18b1 (2-1st) to be laser processed by a second laser device 11 when multiple laser devices 11 are arranged in the transport direction and laser processing is performed.

Figure 14(b) shows the state in which the first object 18a1 (1-1st) and the second object 18b1 (2-1st) in Figure 14(a) have moved a distance L0. Figure 14(b) shows the processing start positions of the first object 18a2 (1-2nd) and the second object 18b2 (2-2nd) that are to be laser processed second by the laser light from each of the multiple laser devices 11.

As shown in FIG. 14, when multiple laser devices 11 are arranged in the transport direction, the first object 18a1 (1-1st) to be laser processed by the first laser device 11 and the second object 18b1 (2-1st) to be laser processed by the second laser device 11 must each be transported to a position that is a standby distance L2 away from the position of the laser light 20 at the processing start position.

In addition, the first object 18a2 (1-2nd) to be laser processed by the first laser device 11 and the second object 18b2 (2-2nd) to be laser processed by the second laser device 11 must each be transported to a position that is a standby distance L2 away from the position of the laser light 20 at the processing start position.

In this case, assuming that there are N laser devices 11 (where N is an integer equal to or greater than 2) and the distance laser processed by the same laser device 11 is L0, as shown in FIG. 14(a), the first object 18a1 (1-1st) to be laser processed by the first laser device 11 and the second object 18b1 (2-1st) to be laser processed by the second laser device 11 are positioned at a distance L1/N apart. Also, as shown in FIG. 14(b), the first object 18a2 (1-2nd) to be laser processed by the first laser device 11 and the second object 18b2 (2-2nd) to be laser processed by the second laser device 11 are also positioned at a distance L1/N apart.

Therefore, the laser processing method according to this embodiment satisfies the distance L0/N when the number of laser devices 11 is N (where N is an integer of 2 or more) and the distance laser processed by the same laser device 11 is L0, and satisfies the above formula (6) or formula (7). As a result, the first object 18a to be laser processed by the first laser device 11 and the second object 18b to be laser processed by the second laser device 11 can be transported to a position that is a standby distance L2 away from the position of the laser light 20 at the processing start position. Therefore, the laser processing method according to this embodiment can laser process multiple objects 18 using multiple laser devices 11. At this time, the required lens effective diameter L3 can be minimized by setting the laser optical axis distance of each laser device 11 to the distance L1.

Third Embodiment
The laser processing method of the third embodiment is a laser processing method in which at least a first object and a second object are transported in that order and the multiple objects are processed with multiple laser beams, and when the first object is processed with multiple laser beams from the processing start position to the processing end position, the distance L0 [mm] from the processing start position to the processing end position and the distance L1 [mm] between the first object and the second object satisfy the following formula (III).
L0≦N·L1 (III)
(Here, N represents the number of laser beams and is an integer of 2 or more.)

According to the laser processing method of this embodiment, even when multiple objects 18 including multiple first objects 18a and second objects 18b are laser processed using multiple laser beams 20, the time from the end of processing the multiple first objects 18a to the start of processing the multiple second objects 18b can be sufficiently secured, and the scanning time of the scanning means, the position information of the multiple objects 18, and the attitude information of the multiple objects 18 can be appropriately corrected, thereby suppressing the occurrence of defectively processed products.

The third embodiment will be described in detail below with reference to the drawings. Note that in the third embodiment, the same configurations as those in the first and second embodiments already described will be given the same reference numerals and the description thereof will be omitted.

Figure 15 is a schematic diagram showing an example of the arrangement of objects in the laser processing method of the third embodiment using multiple laser devices 11. In Figure 15, multiple laser devices 11 are arranged in the conveying direction, and a first object 18a1 (1-1st) to be laser processed by a first laser device 11 and a first object 18a2 (1-2nd) to be laser processed by a second laser device 11 are conveyed in this order.

The first object 18a1 (1-1st) to be laser processed by the first laser device 11 and the first object 18a2 (1-2nd) to be laser processed by the second laser device 11 are each laser processed simultaneously.

At the time when processing of the first first object 18a1 (1-1st) and the second first object 18a2 (1-2nd) is completed, the first second object 18b1 (2-1st) and the second second object 18b2 (2-2nd) are located upstream of the processing start positions of the first first object 18a1 (1-1st) and the second first object 18a2 (1-2nd), respectively. By maintaining this positional relationship, if the conveying speed of the object 18 is V [m/s] and the standby distance is L2 [m], then the time from when the first object 18a1 (1-1st) and the second object 18a2 (1-2nd) are laser processed until the first object 18b1 (2-1st) and the second object 18b2 (2-2nd) are laser processed is the conveying speed V [m/s] multiplied by the standby distance L2 [m] (V·L2 [s]).

Furthermore, if the time it takes for mirror 13a (scanning mirror), such as a galvanometer mirror, to return (jump) from the processing end position to the processing start position is t1, and the time it takes to calculate the processing data according to the detected object position and object orientation after detecting the object position and object orientation is t2, then the maximum of each processing time is V·L2 [s].

The distance L1 between the first object 18a and the second object 18b varies depending on the accuracy of object placement on the conveying means side. When the distance L0 is greater than the distance L1 (L0>L1), the waiting distance L2 is less than 0 (L2<0). Since the laser processing device 10 is equipped with a detection means 16, the waiting time L2 can be calculated from the time t3 between the first object 18a and the second object 18b when passing through the detection means 16 and the conveying speed V [m/s].

If the waiting distance L2 is less than 0 (L2<0), laser processing is not performed on the object 18, and the object 18 is transported downstream as is, where it is judged to be a rejected product by the downstream inspection device and is not shipped.

In the laser processing method according to the third embodiment, even if the laser processing device 10 is equipped with multiple laser devices 11, if the lens effective diameter is L3 and the processing width is W, the maximum distance L0max of the distance L0 is the sum of the lens effective diameter L3 and the processing width W (L0max = L3 + W). Since the maximum processing width W is the lens effective diameter L3, the maximum distance L0max is the lens effective diameter L3 multiplied by 2 (L0max = 2 · L3). For example, since the lens effective diameter L3 of the f920 lens is 470 mm, the maximum distance L0max is 940 mm (= 470 mm × 2). On the other hand, the minimum distance L0min of the distance L0 is 0 mm (L0min = 0 mm) because it is a condition in which the target object is not tracked and processed.

Therefore, even when multiple objects 18 are laser-processed using multiple laser beams 20, the laser processing method according to this embodiment can ensure sufficient time between the end of the laser processing of the multiple objects 18 and the start of the processing of the next multiple objects 18 to be laser-processed, and can appropriately correct the scanning time of the scanning means, the position information of the multiple objects 18, and the attitude information of the multiple objects 18, thereby suppressing the occurrence of defectively processed products.

Although the embodiments of the present invention have been described above, the above embodiments are presented as examples, and the present invention is not limited to the above embodiments. The above embodiments can be embodied in various other forms, and various modifications can be made without departing from the gist of the present invention. These embodiments and their variations are included within the scope and gist of the invention, and are included in the scope of the invention and its equivalents set forth in the claims.

Examples of aspects of the embodiment of the present invention are as follows.
<1> A laser processing method in which at least a first object and a second object are transported in this order, and a plurality of objects including the first object and the second object are processed with a laser beam,
a first detection step of detecting, by a detection means, that the first object has been transported to a predetermined position when the first object is to be laser processed;
a second detection step of detecting, by the detection means, that the second object has been transported to the predetermined position when the second object is to be laser processed;
a determination step of determining a processing start position of the second object based on a time from a time when the first object is detected in the first detection step to a time when the second object is detected in the second detection step and a transport speed of the first object and the second object;
an irradiation step of scanning the laser light at the processing start position of the second object determined in the determination step within an effective diameter of a focusing means, and irradiating the laser light to a processing end position;
A laser processing method comprising:
<2> The distance L1 is an average value L1ave of the distances of multiple objects,
The laser processing method according to <1>, wherein the average value L1ave is an average value including at least a minimum value L1min of the distance L1 and a maximum value L1max of the distance L1.
<3> The laser processing method according to <2>, wherein the minimum value L1min and the distance L0 from the processing start position to the processing end position satisfy the following formula (I):
L0≦L1min (I)
<4> The laser processing method according to <2> or <3>, wherein the distance L0 from the processing start position to the processing end position, the minimum value L1min, and the maximum value L1max satisfy the following formula (II):
L1min≦L0≦L1max (II)
<5> In the case where the first object is processed from a processing start position to a processing end position by using a plurality of the laser beams,
The laser processing method according to any one of <1> to <4>, wherein a distance L0 from the processing start position to the processing end position and a distance L1 between the first object and the second object satisfy the following formula (III):
L0≦N·L1 (III)
(In the formula, N represents the number of laser beams and is an integer of 2 or more.)
<6> The laser processing method according to any one of <1> to <5>, wherein the object is a container.
<7> A laser processing apparatus that conveys at least a first object and a second object in this order and processes a plurality of objects including the first object and the second object with a laser beam,
A conveying means for conveying at least the first object and the second object in that order;
a processing means for processing the object with the laser light;
A detection means for detecting the object;
A determination means for determining a processing start position of the second object;
having
the detection means detects that the first object has been transported to a predetermined position when the first object is to be laser processed, and detects that the second object has been transported to the predetermined position when the second object is to be processed with the laser light from a processing start position to a processing end position,
the determining means determines the processing start position of the second object based on a time from when the first object is detected by the detecting means to when the second object is detected and a transport speed of the first object and the second object;
The processing means is a laser processing device that scans the laser light at the processing start position of the second object determined by the determination means within the effective diameter of the focusing means, and irradiates the laser light up to the processing end position.

The laser processing method described in any one of <1> to <6> and the laser processing device described in <7> can solve the problems of the past and achieve the object of the present invention.

REFERENCE SIGNS LIST 10 laser processing device 11 laser device 12 beam expander 13 scanning means 13a mirror 13b mirror 14 irradiation control means 15 focusing means 16 detection means 16a light projecting section 16b light receiving section 18 object 18a, 18a1, 18a2, 18a1 (1-1st), 18a2 (1-2nd) first object 18b, 18b1, 18b2, 18b1 (2-1st), 18b2 (2-2nd) second object 18c third object 20 laser light

JP 2021-037685 A

Claims (7)

A laser processing method for processing a plurality of objects including at least a first object and a second object by conveying the first object and the second object in this order and processing the plurality of objects including the first object and the second object with a laser beam, comprising:
a first detection step of detecting, by a detection means, that the first object has been transported to a predetermined position when the first object is to be laser processed;
a second detection step of detecting, by the detection means, that the second object has been transported to the predetermined position when the second object is to be laser processed;
a determination step of determining a processing start position of the second object based on a time from a time when the first object is detected in the first detection step to a time when the second object is detected in the second detection step and a transport speed of the first object and the second object;
an irradiation step of scanning the laser light at the processing start position of the second object determined in the determination step within an effective diameter of a focusing means, and irradiating the laser light to a processing end position;
A laser processing method comprising: The distance L1 is the average value L1ave of the distances of multiple objects,
2. The laser processing method according to claim 1, wherein the average value L1ave is an average value including at least a minimum value L1min of the distance L1 and a maximum value L1max of the distance L1. 3. The laser processing method according to claim 2, wherein the minimum value L1min and a distance L0 from the processing start position to the processing end position satisfy the following formula (I):
L0≦L1min (I) 3. The laser processing method according to claim 2, wherein the distance L0 from the processing start position to the processing end position, the minimum value L1min, and the maximum value L1max satisfy the following formula (II):
L1min≦L0≦L1max (II) When processing the first object from a processing start position to a processing end position with a plurality of the laser beams,
2. The laser processing method according to claim 1, wherein a distance L0 from the processing start position to the processing end position and a distance L1 between the first object and the second object satisfy the following formula (III):
L0≦N·L1 (III)
(In the formula, N represents the number of laser beams and is an integer of 2 or more.) The laser processing method according to claim 1, wherein the object is a container. A laser processing apparatus that conveys at least a first object and a second object in this order and processes a plurality of objects including the first object and the second object with a laser beam,
A conveying means for conveying at least the first object and the second object in that order;
a processing means for processing the object with the laser light;
A detection means for detecting the object;
A determination means for determining a processing start position of the second object;
having
the detection means detects that the first object has been transported to a predetermined position when the first object is to be laser processed, and detects that the second object has been transported to the predetermined position when the second object is to be processed with the laser light from a processing start position to a processing end position,
the determining means determines the processing start position of the second object based on a time from when the first object is detected by the detecting means to when the second object is detected and a transport speed of the first object and the second object;
The processing means is a laser processing device that scans the laser light at the processing start position of the second object determined by the determination means within the effective diameter of the focusing means, and irradiates the laser light up to the processing end position.

Images