JP2018099698A - Laser beam irradiation method, laser beam irradiation device, and manufacturing method of sheet fused body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a device which can directly monitor axis deviation of laser beam caused by a temperature drift and the like during laser irradiation, that is, during processing a work piece in a final optical unit including a galvano mirror optical system.SOLUTION: In a laser beam irradiation method, while a work piece 70 is supported on a support member 61 with an aperture 60, laser beam 13 is applied through the aperture 60 on the work piece 70. The work piece 70 is processed while an imaging device 30 images an irradiation state of the laser beam 13 on the work piece 70. A light source 12 and the imaging device 30 are arranged so that an irradiation axis of the laser beam 13 and an optical axis of the imaging device 30 are coaxial. An image of an irradiation sign of the laser beam 13 in the work piece 70 and the support member 61 in the coaxial state is simultaneously obtained by the imaging device 30, and a distance from a reference position to the irradiation sign 71 in the support member 61 is measured to obtain deviation amount of the irradiation position of the laser beam 13. Existence of the deviation is determined to correct it.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a laser light irradiation method and a laser light irradiation apparatus. The present invention also relates to a method for producing a sheet fusion body.

  When irradiating an object with laser light output from a laser oscillator, the preset optical axis may change over time due to temperature changes in the laser oscillator or the optical member placed on the optical path. The optical axis may shift due to aging of the device. A method for aligning such a deviation of the optical axis has been proposed.

  For example, Patent Document 1 discloses a laser oscillator 1 that generates laser light, an XY galvanomirror system that scans the laser light, and an XY galvanomirror for the purpose of automatically correcting a shift in laser beam irradiation position caused by secular change. A laser positioning processing apparatus having a laser head 2 provided with a scan lens that converges laser light emitted from the system is described. In this apparatus, it is possible to image the positioning reference mark 22 fixedly arranged corresponding to the processing plane, the workpiece fixed to the processing plane and the positioning reference mark 22, and the laser beam irradiation axis. The imaging camera 30 with which the optical axis is linked, the image processing device 23 for detecting the deviation amount of the laser light irradiation position from the image signal obtained by imaging the positioning reference mark 22 with the imaging camera 30, and the deviation amount are corrected in the XY galvanometer mirror system. And a control means such as a controller 4 for performing the scanning.

  The applicant first reflects the first light source 21 of the laser light 13, the second light source 22 that generates the misalignment detection light 23 having a wavelength different from that of the laser light 13, and the misalignment detection light 23. The first dichroic mirror 41 that transmits the laser beam 13 and coaxially transmits both the light and the displacement detection light 23 are reflected, the irradiation laser beam 13 is transmitted, and only the irradiation laser beam 13 is finally obtained. The irradiation apparatus 10 including the second dichroic mirror 42 guided to the optical unit 43 and the two-dimensional detector 44 that receives the misalignment detection light 23 reflected by the second dichroic mirror 42 has been proposed. In this irradiation apparatus 10, it is determined whether or not the laser beam 13 is irradiated on the irradiation target position of the object T based on the detection position of the misalignment detection light 23 received by the two-dimensional detector 44.

JP 11-309593 A Japanese Patent Laid-Open No. 2006-115829

  The technique described in Patent Literature 1 performs positioning in a state where the workpiece is fixed or stopped, and cannot determine whether the irradiation target position is accurately irradiated to the workpiece being conveyed. . Although the technique described in Patent Document 2 can determine and correct whether the optical axis of the laser beam up to the final optical unit including the galvanometer mirror optical system has shifted, the temperature drift or the like in the final optical unit If the optical axis shift occurs due to the above, the optical axis shift of the laser beam cannot be determined and corrected in principle.

  Therefore, the subject of this invention is providing the laser beam irradiation method and irradiation apparatus which can eliminate the fault which the prior art mentioned above has. Moreover, the subject of this invention is providing the manufacturing method of the sheet | seat fused body using these methods and apparatuses.

The present invention is a laser light irradiation method for irradiating a workpiece while scanning a laser beam emitted from a light source by controlling an irradiation head equipped with a galvanometer mirror optical system,
In a state where the workpiece is supported on a support member having an opening, a laser beam is irradiated from the side of the support member toward the workpiece through the opening, and the laser beam on the workpiece A process of processing the workpiece while imaging the irradiation state of
In the irradiation method, the laser light source and the imaging device are arranged so that the laser beam irradiation axis and the optical axis of the imaging device are coaxial.
In the step, the image of the laser beam irradiation trace on the workpiece and the image of the support member are simultaneously acquired in the coaxial state by the imaging device, and the distance from the reference position on the support member to the irradiation trace Thus, the present invention provides a laser light irradiation method that makes it possible to obtain the amount of displacement of the position of the laser light irradiation trace.

Further, the present invention has an irradiation head equipped with a galvanomirror optical system and a light source of laser light,
With the workpiece supported on a support member having an opening, irradiation is performed while scanning the laser beam from the support member side through the opening toward the workpiece. A laser beam irradiation device used for processing,
An imaging device for imaging an irradiation state of the laser beam on the workpiece;
The present invention provides a laser light irradiation device in which the light source of laser light and the imaging device are arranged so that the irradiation axis of the laser light and the optical axis of the imaging device are coaxial.

Furthermore, the present invention divides the sheet laminate by irradiating a laser beam onto the sheet laminate in which a plurality of sheets are stacked, and at the same time, cut edges of the plurality of sheets generated by the division. Is a method for producing a sheet fusion body, in which a seal edge is formed by fusing
The laser beam emitted from the light source is scanned from the side of the support member by controlling the irradiation head equipped with the galvanomirror optical system in a state where the sheet laminate is supported on the support member having an opening. While irradiating the sheet laminate, and processing the workpiece while imaging the irradiation state of the laser beam on the workpiece with an imaging device,
In the manufacturing method, the light source of the laser light and the imaging device are arranged so that the irradiation axis of the laser light and the optical axis of the imaging device are coaxial,
In the step, the image of the laser beam irradiation trace and the image of the support member in the sheet laminate are simultaneously acquired in the coaxial state by the imaging device, and from the reference position on the support member to the position of the irradiation mark. By obtaining the distance, it is possible to provide a method for manufacturing a sheet-fused body in which the amount of deviation of the position of the laser beam irradiation trace can be acquired.

  According to the present invention, it is possible to directly monitor an irradiation position shift of laser light caused by a temperature drift or the like on a final optical unit including a galvanometer mirror optical system during laser irradiation, that is, during processing of a workpiece.

FIG. 1 is a schematic view showing a main part of a laser beam irradiation apparatus used in the present invention. FIG. 2A is a cross-sectional view in the thickness direction showing the positional relationship between the workpiece and the support member, and FIG. 2B is a plan view of the support member. FIG. 3 is an example of an image obtained by imaging a state when a workpiece is irradiated with laser light. FIG. 4 is a perspective view showing a pants-type disposable diaper as an example of a sheet fusion product manufactured according to the present invention. 5 is a cross-sectional view taken along line VI-VI in FIG. FIG. 6 is a schematic diagram showing a manufacturing process of the pants-type disposable diaper shown in FIG. FIG. 7 is a schematic diagram showing a laser-type joining device used for manufacturing the pants-type disposable diaper shown in FIG.

  The present invention will be described below based on preferred embodiments with reference to the drawings. FIG. 1 schematically shows the main part of a laser beam irradiation apparatus used in the present invention. The laser beam irradiation apparatus includes an irradiation head 10 as a final optical unit in the apparatus. The irradiation head 10 has an XY galvanometer mirror optical system 11. The XY galvanometer mirror optical system 11 includes a device with a mirror on a motor shaft, and is used to scan and irradiate laser light within an XY plane of a workpiece to be irradiated with laser light. It is. “Lasing and irradiating laser light” refers to irradiating laser light continuously or intermittently so that the scanning trajectory of the laser light is linear, curved, or a combination thereof. Such a structure of the galvanometer mirror optical system for irradiating the laser beam is well known in the art. An example of laser beam scanning trajectory includes a mode in which laser light is irradiated linearly. The scanning speed of the laser beam by the XY galvanometer mirror optical system 11 depends on the processing speed of the workpiece, the processing area, and the distance from the exit port of the final unit to the processing point, but the upper limit is about 10,000 mm / sec. is there. Thus, in order to scan a laser beam at high speed, the XY galvanometer mirror optical system 11 is required to be lightweight. Therefore, relatively low density materials such as beryllium, silicon and aluminum are used in the conventional XY galvanometer mirror optical system. Among them, it is preferable to use beryllium, which is a member having the lowest density and light weight, in applications for scanning at high speed. However, a low-density material is a material whose temperature is likely to rise because the amount of heat (heat capacity) required for an increase of 1 ° C. per unit volume is small. Therefore, an XY galvanometer mirror optical system using a low density material is likely to cause temperature drift. Although the XY galvanometer mirror optical system has such disadvantages, as described later, according to the present invention, even when the irradiation position is deviated from the irradiation position due to temperature drift or the like, the laser The light irradiation position can be easily returned to an appropriate position.

The irradiation head 10 includes a light source 12 that emits laser light. As the laser light source 12, an appropriate one is used according to the type of workpiece and the purpose of irradiation, such as CO ₂ laser, YAG laser, LD laser (semiconductor laser), YVO ₄ laser, fiber laser, and the like. Can be mentioned.

  The laser light 13 emitted from the light source 12 passes through the lens group 14 and the dichroic mirror 15 provided in the irradiation head 10 and reaches the XY galvanometer mirror optical system 11 as indicated by a long dotted line in FIG. The laser light 13 that has reached the XY galvanometer mirror optical system 11 is irradiated to a workpiece (not shown) with its traveling direction changed by the XY galvanometer mirror optical system 11. The lens group 14 forms a scan lens optical system in which a plurality of lenses are arranged in series. At least one of the plurality of lenses is a scan lens optical system 14a. The scan lens optical system 14 a is movable in the front-rear direction of the optical axis passing through the scan lens optical system 14 a according to the distance to the planned irradiation position of the laser light 13. As a result, when the laser beam is scanned during processing, the spot diameter of the laser beam 13 irradiated on the workpiece can be fixed even if the distance from the galvano mirror optical system to the planned irradiation position changes. It becomes.

  The dichroic mirror 15 is also called a multilayer optical function reflecting mirror or a dichroic mirror, and is a kind of mirror manufactured using a special optical material. The dichroic mirror 15 has a characteristic of reflecting light of a specific wavelength and transmitting light of other wavelengths. As the dichroic mirror 15 used in the present embodiment, a dichroic mirror 15 having a property of transmitting the laser light 13 emitted from the light source 12 and reflecting the light emitted from the illumination described later is preferably used. The laser beam 13 emitted from the light source 12 may be reflected and may have a property of transmitting light emitted from illumination described later.

  The laser beam irradiation apparatus including the irradiation head 10 has illumination 20 in addition to the irradiation head. The illumination 20 is used to illuminate the irradiation position of the laser beam 13 on the workpiece. It is advantageous that the wavelength of light emitted from the illumination 20 (hereinafter, this light is also referred to as “illumination light”) 21 is in the wavelength range that can be imaged by the imaging apparatus described later. As shown by a short dotted line in FIG. 1, the illumination light 21 is transmitted through the half mirror 22, reflected by the dichroic mirror 15, and enters the XY galvanometer mirror optical system 11. The illumination light 21 reflected by the XY galvanometer mirror optical system 11 illuminates the irradiated portion of the laser beam 13 on the workpiece.

  The laser light irradiation device further includes an imaging device 30. The imaging device 30 is used for imaging an irradiation state of laser light on a workpiece. The imaging device 30 can directly image a state in which the workpiece is irradiated with the laser beam 13 during laser irradiation. Examples of such an imaging device 30 include a CMOS camera and a CCD camera, among which an area camera and a line camera are mentioned, among which a camera called a high speed camera or a high speed camera is mentioned. However, it is not limited to these. When a high-speed camera is used as the imaging device 30, the frame rate of the high-speed camera depends on the spot diameter and the scanning speed. For example, when scanning at 2,000 mm / sec with a spot diameter of 1 mm, the frame rate is 2,000 fps or more. Preferably there is.

  The state of the irradiated portion of the laser beam 13 on the workpiece is reflected by the dichroic mirror 15 and the half mirror 22 after being reflected by the XY galvanometer mirror optical system 11 as shown by a one-dot chain line in FIG. It enters the device 30.

  The operations of the XY galvanometer mirror optical system 11 and the scan lens optical system 14a in the irradiation head 10 of the laser beam irradiation apparatus described above are controlled by the control unit 40 provided in the irradiation apparatus. The control unit 40 is a device composed of computer hardware and software. The XY galvanometer mirror optical system 11 and the scan lens optical system 14a are electrically connected to the control unit 40, and are configured to operate by receiving a command generated from the control unit 40. In addition, the imaging device 30 described above and, if necessary, the illumination light 21 are also electrically connected to the control unit 40. Imaging data acquired by the imaging device 30 is transmitted to the control unit 40. The imaging data transmitted to the control unit 40 is processed by an image processing unit 41 that forms part of the control unit 40. By this processing, the irradiation position of the laser beam on the workpiece is calculated, and the position information is sent to the controller 42 that forms a part of the control unit 40. The controller 42 stores the position information in the coordinate storage unit 43 and calculates the appropriate positions of the XY galvanometer mirror optical system 11 and the scan lens optical system 14 a in the position command unit 44. The position information calculated by the position command unit 44 is sent to a driver unit 45 that forms part of the control unit 40. The driver unit 45 sends an operation instruction to the XY galvanometer mirror optical system 11 and the scan lens optical system 14a based on the position information.

  An external encoder 50 is also connected to the control unit 40. The external encoder 50 is used to specify the position and moving speed of the workpiece to be conveyed. For example, in an embodiment shown in FIG. 7 to be described later, the rotation of the cylindrical support member 121 is counted by an external encoder 50 attached in the vicinity of the support member 121 to generate a position signal. The controller 40 is notified of the position of the opening 127 and the moving speed of the workpiece 70. In addition to the external encoder 50, a processing start position detector 51 is also connected to the controller 40. The processing start position detection unit 51 is configured by, for example, an optical sensor, a fiber sensor, or the like, and transmits a timing signal for irradiating the workpiece 70 with the laser beam 13, that is, a processing start signal to the control unit 40. It is configured.

  In the present invention, as shown in FIG. 2A, the workpiece 70 is supported on the workpiece 70 through the opening 60 from the support member 61 side in a state where the workpiece 70 is supported on the support member 61 having the opening 60. The laser beam 13 is irradiated toward the target. And the irradiation trace of the laser beam 13 is imaged by the imaging device 30 described above while processing the workpiece 70. Although there is no restriction | limiting in particular in the shape of the opening part 60, In embodiment shown, it is preferable to employ | adopt a slit-shaped opening part. The number of openings 60 is not limited, and one or more openings may be used. In the case where a plurality of openings are used, it is preferable that the laser beam is irradiated intermittently. Specific examples of processing of the workpiece 70 include, but are not limited to, fusing, fusing, or a combination thereof. As shown in FIG. 2B, the opening 60 shown in FIG. 2 has a slit-like linear shape. However, the shape of the opening 60 is not limited to a straight line, and may be another shape, for example, a curved line, or a combination of a curved line and a straight line. The width R of the opening 60, that is, the upper limit value of the distance between the end portions 62a and 62b (see FIG. 2A) of the opening 60 is not particularly limited as long as it falls within the field of view of the camera. The lower limit of the width is determined by the relationship with the spot diameter of the laser beam 13, and is generally about the same as the spot diameter.

  When irradiating the workpiece 70 with the laser beam 13 according to the present invention, as shown in FIG. 1, the light source of the laser beam 13 is arranged so that the irradiation axis of the laser beam 13 and the optical axis 31 of the imaging device 30 are coaxial. 12 and the imaging device 30 are arranged. In addition, the illumination 20, the light source 12 of the laser light 13, and the imaging device 30 are arranged so that the optical axis of the illumination light 21, the irradiation axis of the laser light 13, and the optical axis 31 of the imaging device 30 are coaxial. Arrange it. “Coaxial” means that the irradiation axis of the laser beam 13, the optical axis 31 of the imaging device 30, and the optical axis of the illumination light 21 are matched. The “optical axis” refers to a symmetry axis that passes through the center of the optical imaging system.

  As shown in FIG. 1, the optical axis 31 (one-dot chain line) of the imaging device 30 and the illumination light 21 (short dotted line) are merged by the half mirror 22 to be coaxial, and the irradiation axis (long dotted line) of the laser light 13 is The dichroic mirror 15 joins and becomes coaxial, and these three are coaxially directed toward the workpiece. In order to make these three states coaxial, it is necessary to adjust the incident angles of the optical axis 31 of the imaging device 30 and the optical axis of the illumination light 21 to the dichroic mirror 15. Further, it is necessary to adjust the incident angle of the optical axis 31 of the imaging device 30 to the half mirror 22.

  In the state where the optical axes of the three parties are coaxial, the laser beam 13 is irradiated from the support member 61 side toward the workpiece 70 through the opening 60 as shown in FIG. . At this time, the workpiece 70 may be stationary or moved. Regarding the support member 61, when the workpiece 70 is stationary, the support member 61 is also stationary. When the workpiece 70 is moved, the support member 61 is The movement is the same as the movement of the object 70. When the work piece 70 and the support member 61 are in a moved state, the moving speed may be constant speed or constant acceleration. In either case, the irradiation position on the workpiece 70 is monitored by the external encoder 50 described above. When the work piece 70 and the support member 61 are in a moved state, it is over 0 m / s and about 10 m / s or less.

  When the workpiece 70 moves, when starting the operation of the laser beam irradiation apparatus, the control unit 40 (see FIG. 1) sets zero as the initial value of the current position and the moving speed of the workpiece 70. Keep it. Also, zero is set as an initial value of an offset amount B described later of the irradiation position of the laser beam 13. The operation of the apparatus is started from this state, a signal from the machining start position detector 51 (see FIG. 1) is acquired, and information on the current position and phase velocity of the workpiece 70 is continuously obtained by the external encoder 50 (see FIG. 1). Get A. Then, a processing position command value is created based on the information A and an offset amount B described later. Based on this command value, the laser beam 13 is irradiated.

  While the workpiece 70 is being processed by the irradiation of the laser beam 13, the image of the irradiation mark of the laser beam 13 on the workpiece 70 and the image of the support member 61 are simultaneously acquired in the coaxial state by the imaging device 30. “Acquire in the coaxial state” means to acquire an image in a state where the irradiation axis of the laser beam 13, the optical axis 31 of the imaging device 30, and the optical axis of the illumination light 21 are coaxial as described above. Say. Acquisition of these images is performed continuously or intermittently during processing of the workpiece 70. “Continuous” means that, for example, when an image is captured by an area camera, if a spot diameter is 1 mm and scanning is performed at 2,000 mm / s, image acquisition is performed at a frame rate of 2,000 fps or more. Furthermore, when acquiring images continuously, a line camera may be used. FIG. 3 shows an example of an irradiation mark of the laser beam 13 and an image of the support member 61 obtained according to the present invention. In FIG. 3, the laser beam 13 is scanned from the top to the bottom in the figure, and the laser beam 13 is irradiated in a straight line. In FIG. 3, a region between the ends of the openings indicated by reference numerals 62 a and 62 b is an opening, and the workpiece 70 is exposed in the opening. On the workpiece 70, an irradiation mark 71 caused by the irradiation of the laser beam 13 is shown as a black region. In the black region, the workpiece 70 is thermally decomposed and melted by the irradiation of the laser beam 13.

  When the image shown in FIG. 3 is acquired, the image data is processed by the image processing unit 41 in the control unit 40. The image processing unit 41 uses a known shading process, binarization process, or the like, and obtains the distance from the reference position on the support member 61 to the irradiation mark 71 by such a process. “Irradiation trace” means not only an irradiation trace (position P in FIG. 3) at the moment of laser light irradiation, but also immediately after laser light irradiation, and a hole is formed in the workpiece 70 by the laser light. It also means an irradiation mark (position Q in FIG. 3) reflected in the field of view of the acquired image in a state where is formed.

  There is no restriction | limiting in particular in the reference position in 61 in a supporting member. For example, one end 62a of the opening 60 formed in the support member 61 is used as a reference line as a reference position, and an irradiation mark 71 (FIG. 3) at the moment when laser light is irradiated from the end 62a as the reference line. The distance D1 from the end 62b to the outer edge of the irradiation mark 71 and the distance D2 from the end 62b to the outer edge of the irradiation mark 71 can be obtained. When the distance D1 and the distance D2 are within a predetermined value range, that is, the deviation amount is within a set threshold value range, the irradiation position of the laser beam 13 is appropriate, and deviation occurs in the irradiation position. Judge that it is not. This determination is made in the image processing unit 41. On the other hand, when the distance D1 and the distance D2 are outside the predetermined value range, that is, the deviation amount is outside the set threshold value range, the irradiation position of the laser beam 13 is not appropriate and the irradiation position is shifted. Judge that it has occurred. In this case, the image processing unit 41 calculates a correction amount corresponding to the degree of deviation, that is, an offset amount B, and based on the offset amount B, the driver unit 45 corrects the irradiation position of the laser light 13. Is transmitted to the irradiation head 10. Upon receiving this command, the irradiation head 10 corrects the operation of the XY galvanometer mirror optical system 11 and / or the scan lens optical system 14a so that the laser beam 13 irradiates an appropriate position. Further, based on the offset amount B and the information A regarding the current position and phase velocity of the workpiece 70 and the support member 61 acquired from the external encoder 50 (see FIG. 1), a new processing position, that is, irradiation of the laser beam 13 is performed. A position command value is created by the control unit 40 (see FIG. 1).

  When obtaining the above-mentioned distance D1 and distance D2, as described above, the position at the moment of irradiating the workpiece 70 with the laser beam 13 in the irradiation mark 71 can be targeted. This position is the position indicated by the symbol P in FIG. 3 as described above. Instead of this position or in addition to this position, the position of the irradiation mark observed in the imaging field immediately after the position indicated by the symbol P of the laser beam 13 in the field imaged by the imaging device 30 is targeted. The above-mentioned distance D3 and distance D4 can be obtained. This position is the position indicated by the symbol Q in FIG. Whether the position of P or the position of Q is employed when obtaining the distance from the reference position to the irradiation mark 71 on the support member 61 depends on the type of the workpiece 70, the width R of the opening 60, the laser beam. However, if the position of P is adopted, the material around the processed portion is less likely to sink in the width R direction of the opening 60 than when the position of Q is adopted. This is advantageous in terms of ease of determination when the process proceeds quickly. On the other hand, when the position of Q is adopted, the position of the laser beam is shifted as compared with the case where the position of P is adopted, and stray light such as arc light is generated by irradiating the support member 61 and affects image processing. It is advantageous in some cases.

  In the acquisition of an image by the imaging device 30, the boundary between the workpiece 70 and the support member 61 is further clarified, and from the viewpoint of measuring the distance D1 and the distance D2 more accurately, the workpiece 70 and the support member 61 are However, it is preferable that they have colors that can be distinguished from each other in the imageable wavelength range of the imaging device 30. For example, when the imaging device 30 is capable of imaging the visible light wavelength region, it is preferable that the difference in brightness L value between the workpiece 70 and the support member 61 is large. For example, when the brightness difference between them is 8 bits and 50 or more, the boundary between the workpiece 70 and the support member 61 becomes even clearer.

  By continuously performing the above operations, even if the laser beam irradiation position is shifted due to temperature drift in the final optical unit including the galvanometer mirror optical system, the shift can be monitored directly even during laser irradiation. Can do. Further, the irradiation position can be quickly corrected to an appropriate position. Therefore, the workpiece 70 can be processed successfully.

  The laser light irradiation method and laser light irradiation apparatus of the present invention can be applied to various workpieces. As an example, an embodiment in which the present invention is applied to a method for manufacturing a sheet fusion body will be described below.

  4 and 5 show a pants-type disposable diaper 1 which is an example of a sheet fusion body. The diaper 1 includes an absorbent main body 2 and an exterior body 3 that is disposed on the non-skin contact surface side of the absorbent main body 2 and fixes the absorbent main body 2. The side edge portions of the body 3 and the side edge portions of the exterior body at the back side portion 1B are joined to form a pair of side seal portions 4a and 4b, a waist opening portion 8 and a pair of leg opening portions 9a and 9b. A pants-type disposable diaper. The exterior body 3 includes an outer layer sheet 3a and an inner layer sheet 3b. This diaper 1 divides the sheet laminate by irradiating a laser beam onto a sheet laminate in which a plurality of sheets are stacked, and at the same time, cut edges of a plurality of sheets generated by the division. 6 and 7 according to the method for manufacturing a sheet fusion product, in which a sealing edge is formed by fusing the sealant.

  As shown in FIG. 6, between the strip-shaped outer layer sheet 3a continuously supplied from the original fabric roll (not shown) and the strip-shaped inner layer sheet 3b continuously supplied from the original fabric roll (not shown). In addition, a plurality of waist elastic members 5 forming waist gathers, waist elastic members 6 forming waist gathers, and leg elastic members 7 forming leg gathers are extended to a predetermined extension rate. Arrange. At this time, a hot melt adhesive is applied to the waist elastic member 5 and the waistline elastic member 6 continuously or intermittently by an adhesive coating machine (not shown), and the leg elastic member 7 is They are arranged while forming a predetermined leg-circumferential pattern via a known swing guide (not shown) that reciprocates perpendicular to the sheet flow direction. In addition, before the belt-like outer layer sheet 3a and the belt-like inner layer sheet 3b are overlaid, an adhesive coating machine (not shown) is attached to a predetermined part of one or both surfaces of both sheets. ) To apply hot melt adhesive.

  And as shown in FIG. 6, between the pair of nip rolls 111, 111, a belt-like outer layer sheet 3a in which a waist elastic member 5, a waistline elastic member 6 and a leg elastic member 7 are sandwiched in an expanded state and a belt-like outer layer sheet 3a. By feeding and pressurizing the inner layer sheet 3b, a band-shaped exterior body 3 is formed in which a plurality of elastic members 5, 6, and 7 are arranged in an expanded state between the band-shaped sheets 3a and 3b. After that, by using an elastic member pre-cutting means (not shown), the plurality of waistline elastic members 6 and the plurality of leg elastic members 7 are pressed so as to correspond to positions where the absorbent main body 2 described later is disposed. Then, it is divided into a plurality of pieces so that the contractile function is not expressed. Examples of the elastic member precut means include an elastic member dividing portion used in the method for manufacturing a composite elastic member described in JP-A-2002-253605.

  Next, as shown in FIG. 6, an adhesive such as a hot melt adhesive is applied in advance to the absorbent main body 2 manufactured in a separate process, and the absorbent main body 2 is rotated by 90 degrees to form a belt-shaped outer package. 3 is intermittently supplied and fixed on the inner layer sheet 3 b constituting the sheet 3. The adhesive for fixing the absorbent main body may be applied in advance to the planned arrangement position of the absorbent main body 2 in the inner layer sheet 3b instead of the absorbent main body 2.

  Subsequently, as shown in FIG. 6, a leg hole LO ′ is formed inside the annular portion that is annularly surrounded by the leg elastic member 7 in the strip-shaped exterior body 3 in which the absorbent main body 2 is disposed. This leg hole forming step can be carried out by using a technique similar to that in a conventional method for manufacturing this type of article, such as a rotary cutter and a laser cutter. In the present embodiment, the leg holes are formed after the absorbent main body 2 is arranged on the belt-shaped outer package 3, but the leg holes may be formed before the absorbent main body 2 is arranged.

  Next, the belt-shaped exterior body 3 is folded in the width direction (a direction orthogonal to the conveyance direction of the exterior body 3). More specifically, as shown in FIG. 6, both side portions 3 ′ and 3 ′ along the conveying direction of the strip-shaped exterior body 3 are folded back so as to cover both ends in the longitudinal direction of the absorbent body 2. After fixing both longitudinal ends of 2, the exterior body 3 is folded in two along the width direction together with the absorbent main body 2. In this way, the diaper continuous body 1 'is obtained.

  The diaper continuum 1 ′ thus manufactured is irradiated with laser light using the laser bonding apparatus 120 shown in FIG. 7 including the laser light irradiation apparatus of the present invention, and a pair of side seal portions 4a and 4b. The pants-type disposable diaper 1 as a sheet fusion body comprising the outer package 3 having the above is continuously manufactured.

  The laser bonding apparatus 120 will be described. As shown in FIG. 7, the apparatus 120 includes a hollow cylindrical roll 123 including a cylindrical support member 121 that is rotationally driven in the direction of arrow S, and the cylindrical roll 123. The irradiation head 10 which irradiates the laser beam 13 toward the cylindrical support member 121 which is distribute | arranged to the hollow part and forms the surrounding surface part of the cylindrical roll 123 is provided. The cylindrical support member 121 has a first surface 121a facing outward and a second surface 121b facing inward. The irradiation head 10 is disposed on the second surface 121 b side of the support member 121.

  The support member 121 forms a peripheral surface portion of the cylindrical roll 123, and is sandwiched and fixed between a pair of annular frames (not shown) that form the left and right side edges of the cylindrical roll 123. The support member 121 is composed of a single annular member having the same length as the circumferential length of the annular frame, for example, a metal material such as iron, aluminum, stainless steel, copper, or a material having heat resistance such as ceramics. Consists of.

  The support member 121 has an opening 127 that penetrates the support member 121 in the thickness direction, which is a light passage portion through which laser light can pass. The opening 127 has a rectangular shape in plan view, and its longitudinal direction coincides with the width direction of the support member 121, that is, the direction indicated by the symbol X in FIG. 7, so as to extend in the circumferential direction of the cylindrical support member 121. A plurality are formed at predetermined intervals. In other words, the opening 127 extends on the circumferential surface of the cylinder so as to coincide with a direction parallel to the axial length direction of the rotation axis of the cylinder. The support member 121 allows the laser light 13 to pass through the opening 127, but does not allow the laser light 13 to pass through the portion other than the opening 127. As a method of forming the opening 127 in the support member 121, 1) a method of drilling the opening 127 in a predetermined portion of the support member 121 by etching, punching, laser processing, or the like, or 2) a single support member 121 is used. In place of the annular member, a plurality of curved rectangular members are used, and the plurality of members are arranged between a pair of frame bodies (not shown) at a predetermined interval in the circumferential direction of the frame bodies. Is mentioned.

  The laser-type bonding apparatus 120 includes a plurality of pressure heads 126 in addition to the support member 121 and the irradiation head 10 described above. The pressure head 126 is used to press the diaper continuous body 1 ′ supported on the first surface 121 a of the support member 121 described above. Each pressure head 126 has a rotation axis on an extension line of the rotation axis of the cylindrical roll 123, and is arranged on the peripheral surface of the second cylindrical roll 125 arranged adjacent to the cylindrical roll 123. The second cylindrical roll 125 rotates in synchronization with the cylindrical roll 123. In FIG. 7, each pressure head 126 is attached to a second cylindrical roll 125, which is a separate member from the cylindrical roll 123. Instead, each pressure head 126 is attached to the cylindrical roll 123. It is also possible to attach.

  As the second cylindrical roll 125 rotates in synchronization with the cylindrical roll 123, each pressure head 126 is rotated in the same direction as the rotation direction of the support member 121 constituting the cylinder of the cylindrical roll 123 and around the support member 121. It is possible to go around the peripheral surface of the support member 121 at the same speed as the speed. Details of the laser-type bonding apparatus 120 having such a structure are described in, for example, Japanese Patent Application Laid-Open No. 2016-112166 related to an earlier application of the present applicant.

  An irradiation head 10 that irradiates the laser beam 13 toward the support member 121 that forms the peripheral surface portion of the cylindrical roll 123 is provided in the hollow portion of the hollow cylindrical roll 123 that is the support member 121. The irradiation point can be arbitrarily moved in both the circumferential direction of the cylindrical roll 123 and the direction orthogonal to the circumferential direction. This irradiation head 10 corresponds to the final optical unit.

  When manufacturing the diaper 1 using the laser-type bonding apparatus 120 having the above-described configuration, the diaper continuous body 1 ′ is continuously conveyed, and one surface thereof is formed with the peripheral surface portion of the cylindrical roll 123 and the laser beam 13. The diaper continuous body 1 ′ having an opening 127 through which the pressure can be passed and brought into contact with the outer surface of the support member 121 and pressed by the pressure head 126 is opened from the support member 121 side. By irradiating the laser beam 13 through 27, the diaper continuous body 1 'is divided, and at the same time, the cut edges of the plurality of sheets in the pressurized state generated by the division are fused. Side seal portions 4a and 4b are formed. Examples of the configuration of the outermost surface of the diaper continuous body 1 ′ include, but are not limited to, a film-like or fibrous resin, or a combination of the shapes. From the viewpoint of successfully performing this fusion, it is preferable that the outermost surface of the diaper continuous body 1 ′, which is a workpiece, be composed of a nonwoven fabric. If this nonwoven fabric is composed of thermoplastic resin fibers, the fusion can be performed even more successfully.

  Whether or not the laser beam 13 is properly irradiated to the irradiation position T (see FIG. 7) of the laser beam 13 in the diaper continuous body 1 ′ when the side seal portions 4a and 4b are formed, that is, the irradiation position of the laser beam 13 Whether or not there is a deviation can be determined by the above-described operation. When it is determined that the laser beam 13 is not irradiated to the irradiation scheduled position T, the irradiation of the laser beam 13 is returned to an appropriate position by performing the correction as described above. According to the present embodiment, the peripheral surface of the cylindrical support member 121 rotating around the axis is irradiated with the laser beam 13 in parallel with the axial direction and the processing position is imaged. There is an advantage that the changeable focal length of the device 30 is small, and a large imageable area that satisfies the depth of field can be obtained without changing the focus of the camera. In contrast, when the laser beam is irradiated while the planar workpiece is conveyed in one direction, the change in the focal length of the laser beam 13 and the imaging device 30 becomes large. The imageable area that satisfies the depth of field is reduced.

  As mentioned above, although this invention was demonstrated based on the preferable embodiment, this invention is not restrict | limited to the said embodiment. For example, in the embodiment shown in FIGS. 4 to 7, the laser light irradiation method and the laser light irradiation device of the present invention are applied to the manufacture of a pants-type disposable diaper that is an example of an article having a sheet fusion body. It can also be applied to the manufacture of other articles. Examples of other articles include absorbent articles other than the above-described pants-type disposable diapers, such as articles in which the sheet fusion body constitutes a part of the absorbent article, such as sanitary napkins and incontinence pads. Can be mentioned. In addition to absorbent articles, floor cleaning sheets, body wiping sheets, body warming heating tools, and the like can be given. As a sheet fusion body which constitutes an absorptive article, a) A surface sheet which forms a skin contact surface of an absorptive article, and a back sheet which forms a non-skin contact surface extend from a peripheral part of an absorber B) In the sanitary napkin, the top sheet and the wing part forming sheet, the wing part forming sheet and the back sheet, or the top sheet, the wing part forming sheet and the back sheet are fused. And the like.

  In the embodiment, the illumination 20, the light source 12 of the laser light 13, and the imaging device are arranged so that the optical axis of the illumination light 21, the irradiation axis of the laser light 13, and the optical axis 31 of the imaging device 30 are coaxial. 30 is disposed, but instead of using the illumination 20, the light source 12 of the laser beam 13 and the imaging device 30 are arranged so that the irradiation axis of the laser beam 13 and the optical axis 31 of the imaging device 30 are coaxial. May be arranged. Alternatively, although the illumination 20 is used, the irradiation axis of the laser light 13 and the optical axis 31 of the imaging device 30 are coaxial, but the optical axis of the illumination light 21 is not coaxial. The light source 12 and the imaging device 30 may be disposed. However, when these three components are condensed on the workpiece 70 so that the optical axis of the illumination light 21, the irradiation axis of the laser beam 13, and the optical axis 31 of the imaging device 30 are coaxial, the workpiece 70 is processed. This is advantageous in that the irradiation mark generated on the object 70 becomes clearer.

The present invention further discloses the following laser beam irradiation method, laser beam irradiation apparatus, sheet fused body manufacturing method, and absorbent article manufacturing method with respect to the above-described embodiment.
<1>
A laser light irradiation method for irradiating a workpiece while scanning a laser beam emitted from a light source by controlling an irradiation head equipped with a galvanometer mirror optical system,
In a state where the workpiece is supported on a support member having an opening, a laser beam is irradiated from the side of the support member toward the workpiece through the opening, and the laser beam on the workpiece A process of processing the workpiece while imaging the irradiation state of
In the irradiation method, the laser light source and the imaging device are arranged so that the laser beam irradiation axis and the optical axis of the imaging device are coaxial.
In the step, the image of the laser beam irradiation trace on the workpiece and the image of the support member are simultaneously acquired in the coaxial state by the imaging device, and the distance from the reference position on the support member to the irradiation trace A laser beam irradiation method that makes it possible to obtain the amount of deviation of the position of the laser beam irradiation trace.

<2>
The laser beam irradiation method according to <1>, wherein a threshold value of the shift amount is set to determine whether or not the position of the irradiation mark of the laser beam is shifted.
<3>
The laser light irradiation method according to <1> or <2>, wherein the laser light irradiation position is corrected when it is determined that a deviation has occurred in the laser light irradiation position.
<4>
The irradiation head further comprises a scan lens optical system;
The laser beam irradiation method according to any one of <1> to <3>, wherein the scan lens optical system and the galvanometer mirror optical system are controlled to scan the laser beam.
<5>
The laser beam irradiation according to any one of <1> to <4>, wherein the workpiece and the support member have colors that allow them to be distinguished from each other in an imageable wavelength range of the imaging device. Method.
<6>
The imaging device is capable of imaging the wavelength region of visible light;
The laser light irradiation method according to any one of <1> to <5>, wherein a difference in brightness between the workpiece and the support member is 50 or more in 8 bits.

<7>
The laser beam irradiation method according to any one of <1> to <6>, wherein an outermost surface on the irradiation head side of the workpiece is made of a resin.
<8>
The laser beam irradiation method according to any one of <1> to <7>, wherein an outermost surface on the irradiation head side of the workpiece is made of a nonwoven fabric.
<9>
Further using illumination that illuminates the irradiation position of the laser beam on the workpiece,
<1> thru | or which arrange | positions the said illumination, the said light source of a laser beam, and the said imaging device so that the optical axis of the said illumination, the irradiation axis | shaft of a laser beam, and the optical axis of the said imaging device may become coaxial. The laser beam irradiation method according to any one of <8>.
<10>
The laser light irradiation method according to any one of <1> to <9>, wherein a CMOS camera or a CCD camera is used as the imaging device.
<11>
The laser light irradiation method according to any one of <1> to <10>, wherein a high-speed camera is used for the imaging device.

<12>
The laser beam irradiation method according to any one of <1> to <11>, wherein the laser beam is irradiated when the workpiece is stationary or moved.
<13>
The laser light irradiation method according to any one of <1> to <12>, wherein the laser light is irradiated linearly.
<14>
The support member has a first surface facing outward and supporting the workpiece, and a second surface facing inward, and is made of a cylinder that can rotate in one direction,
A plurality of slit-like openings extending in a direction parallel to the axial length direction of the rotation axis of the cylinder are provided on the circumferential surface of the cylinder at predetermined intervals in the circumferential direction of the cylinder. The laser beam irradiation method according to any one of <1> to <13>.
<15>
The irradiation mark at the moment when the laser beam is irradiated is obtained, and by determining the distance from the reference position on the support member to the position of the irradiation mark, the presence or absence of deviation of the irradiation position of the laser beam is determined. 1> thru | or the laser beam irradiation method of any one of <14>.
<16>
Obtaining the position of the irradiation mark observed in the field of view immediately after irradiating the laser beam in the field of view imaged by the imaging device, and determining the distance from the reference position on the support member to the position of the irradiation mark The laser light irradiation method according to any one of the above items <1> to <14>, wherein the presence or absence of a shift in the irradiation position of the laser light is determined by obtaining.

<17>
An irradiation head equipped with a galvanometer mirror optical system and a laser light source;
With the workpiece supported on a support member having an opening, irradiation is performed while scanning the laser beam from the support member side through the opening toward the workpiece. A laser beam irradiation device used for processing,
An imaging device for imaging an irradiation state of the laser beam on the workpiece;
A laser light irradiation apparatus in which the light source of laser light and the imaging device are arranged so that an irradiation axis of laser light and an optical axis of the imaging device are coaxial.
<18>
Further comprising illumination for illuminating the irradiation position of the laser beam on the workpiece,
<17> in which the illumination, the light source of the laser light, and the imaging device are arranged so that the optical axis of the illumination, the irradiation axis of the laser light, and the optical axis of the imaging device are coaxial. The laser beam irradiation apparatus as described.
<19>
By irradiating a laser beam onto a sheet laminate in which a plurality of sheets are stacked, the sheet laminate is divided, and at the same time, the cut edges of the plurality of sheets generated by the division are fused together. A method for manufacturing a sheet fusion body, which forms a seal edge,
The laser beam emitted from the light source is scanned from the side of the support member by controlling the irradiation head equipped with the galvanomirror optical system in a state where the sheet laminate is supported on the support member having an opening. While irradiating the sheet laminate, and processing the workpiece while imaging the irradiation state of the laser beam on the workpiece with an imaging device,
In the manufacturing method, the light source of the laser light and the imaging device are arranged so that the irradiation axis of the laser light and the optical axis of the imaging device are coaxial,
In the step, the image of the laser beam irradiation trace and the image of the support member in the sheet laminate are simultaneously acquired in the coaxial state by the imaging device, and from the reference position on the support member to the position of the irradiation mark. A method for manufacturing a sheet fusion product, in which it is possible to obtain the amount of deviation of the position of the irradiation mark of the laser beam by obtaining the distance of the laser beam.
<20>
The method for producing a sheet fusion body according to <19>, wherein a threshold value of the deviation amount is set, and whether or not there is a deviation in the irradiation position of the laser beam is determined.
<21>
The method for producing a sheet-fused body according to <19> or <20>, wherein the laser light irradiation position is corrected when it is determined that there is a deviation in the laser light irradiation position.

<22>
Manufacture of an absorbent article, wherein the sheet fusion body comprises a part of the absorbent article, comprising the step of producing the sheet fusion body by the production method according to any one of <19> to <21>. Method.
<23>
The absorbent article includes an absorbent main body and an exterior body that is disposed on the non-skin contact surface side of the absorbent main body and fixes the absorbent main body, A pants-type disposable diaper in which a pair of side seal parts is formed by joining both side edges of the exterior body at both side edges and a back side part,
The sheet fusion body constitutes a part of the pants-type disposable diaper,
Folding the strip-shaped exterior body in the width direction and irradiating a predetermined portion of the folded strip-shaped exterior body with laser light, the side seal portion is formed at the same time as the strip-shaped exterior body is divided. The method for producing an absorbent article according to <22>, wherein the sheet fusion body is used.

DESCRIPTION OF SYMBOLS 10 Irradiation head 11 XY galvanometer mirror optical system 12 Light source 13 Laser light 14 Lens group 15 Dichroic mirror 20 Illumination 21 Illumination light 30 Imaging device 40 Control part 50 External encoder 60 Opening part 61 Support member 62a, 62b Opening part 70 Covered Workpiece 71 Irradiation trace of laser light

Claims (9)

A laser light irradiation method for irradiating a workpiece while scanning a laser beam emitted from a light source by controlling an irradiation head equipped with a galvanometer mirror optical system,
In a state where the workpiece is supported on a support member having an opening, a laser beam is irradiated from the side of the support member toward the workpiece through the opening, and the laser beam on the workpiece A process of processing the workpiece while imaging the irradiation state of
In the irradiation method, the laser light source and the imaging device are arranged so that the laser beam irradiation axis and the optical axis of the imaging device are coaxial.
In the step, the image of the laser beam irradiation trace on the workpiece and the image of the support member are simultaneously acquired in the coaxial state by the imaging device, and the distance from the reference position on the support member to the irradiation trace A laser beam irradiation method that makes it possible to obtain the amount of deviation of the position of the laser beam irradiation trace.   The laser beam irradiation method according to claim 1, wherein a threshold value of the shift amount is set to determine whether or not the position of the irradiation mark of the laser beam is shifted.   The laser light irradiation method according to claim 1 or 2, wherein the laser light irradiation position is corrected when it is determined that a deviation occurs in the laser light irradiation position.   The laser beam irradiation method according to any one of claims 1 to 3, wherein the workpiece and the support member have colors that allow them to be distinguished from each other in an imageable wavelength range of the imaging device. Further using illumination that illuminates the irradiation position of the laser beam on the workpiece,
5. The illumination, the light source of laser light, and the imaging device are arranged so that an optical axis of the illumination, an irradiation axis of laser light, and an optical axis of the imaging device are coaxial. The laser beam irradiation method according to any one of the above. An irradiation head equipped with a galvanometer mirror optical system and a laser light source;
With the workpiece supported on a support member having an opening, irradiation is performed while scanning the laser beam from the support member side through the opening toward the workpiece. A laser beam irradiation device used for processing,
An imaging device for imaging an irradiation state of the laser beam on the workpiece;
A laser light irradiation apparatus in which the light source of laser light and the imaging device are arranged so that an irradiation axis of laser light and an optical axis of the imaging device are coaxial. Further comprising illumination for illuminating the irradiation position of the laser beam on the workpiece,
The said illumination, the said light source of a laser beam, and the said imaging device are arrange | positioned so that the optical axis of the said illumination, the irradiation axis | shaft of a laser beam, and the optical axis of the said imaging device may become coaxial. Laser light irradiation device. By irradiating a laser beam onto a sheet laminate in which a plurality of sheets are stacked, the sheet laminate is divided, and at the same time, the cut edges of the plurality of sheets generated by the division are fused together. A method for manufacturing a sheet fusion body, which forms a seal edge,
The laser beam emitted from the light source is scanned from the side of the support member by controlling the irradiation head equipped with the galvanomirror optical system in a state where the sheet laminate is supported on the support member having an opening. While irradiating the sheet laminate, and processing the workpiece while imaging the irradiation state of the laser beam on the workpiece with an imaging device,
In the manufacturing method, the light source of the laser light and the imaging device are arranged so that the irradiation axis of the laser light and the optical axis of the imaging device are coaxial,
In the step, the image of the laser beam irradiation trace and the image of the support member in the sheet laminate are simultaneously acquired in the coaxial state by the imaging device, and from the reference position on the support member to the position of the irradiation mark. A method for manufacturing a sheet fusion product, in which it is possible to obtain the amount of deviation of the position of the irradiation mark of the laser beam by obtaining the distance of the laser beam.   The manufacturing method of the absorbent article in which this sheet fusion body comprises a part of absorbent article including the process of manufacturing the said sheet fusion body by the manufacturing method of Claim 8.