JP6480725B2 - Laser irradiation apparatus and laser irradiation method - Google Patents

Description

  The present invention relates to a laser irradiation apparatus and a laser irradiation method for irradiating an object with laser light.

  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. Various methods for aligning such optical axis deviations have been proposed.

  For example, in Patent Document 1, a laser beam is split in two directions using a beam splitter, and the position of one of the branched laser beams is detected by a two-dimensional position detection device, and the optical axis shift is obtained. The method of adjusting the optical axis by moving the mirror according to the above is described. A method for correcting an optical axis shift using a beam splitter is also described in Patent Document 2.

  On the other hand, Patent Documents 3 and 4 describe a method of correcting the deviation of the optical axis by using a laser light source having two or more wavelengths instead of using a beam splitter.

Special table 2013-202658 gazette JP 2008-203416 A JP 2008-293623 A International Publication No. 2012/108032 Pamphlet

  In the optical axis alignment method using a beam splitter, there is a problem in that energy loss of laser light irradiated to an object occurs due to branching of laser light generated by one light source. On the other hand, if the optical axis alignment method uses a laser light source having two or more wavelengths, there is no loss in the energy of the laser light applied to the object. However, when a laser light source having two or more wavelengths is used, the technique described in Patent Document 3 detects both return lights of laser light of two wavelengths, and the structure of the optical system becomes complicated. There are challenges. In the technique described in Patent Document 4, since the output when all the laser beams having different wavelengths are received by the light receiving element is acquired and the optical axis deviation is detected based on the output value, the wavelengths of those are detected. There is a problem that it is necessary to irradiate an object with all laser beams having different values.

  Therefore, the subject of this invention is providing the laser irradiation apparatus and laser irradiation method which can eliminate the fault which the prior art mentioned above has.

The present invention includes a first light source that generates irradiation laser light for irradiating an object;
A second light source for generating misalignment detection light having a wavelength different from that of the irradiation laser light;
A first reflecting member that changes the traveling direction of the misalignment detection light generated by the second light source;
A first dichroic mirror that reflects the misalignment detection light incident through the first reflecting member and transmits the irradiation laser light incident from the first light source so as to make both lights coaxial;
A second dichroic mirror that is disposed immediately before the final optical unit for irradiating the irradiation laser beam to the object and receives the coaxial irradiation laser beam and misalignment detection light. The second dichroic mirror that reflects the detection light and transmits the irradiation laser light and guides only the irradiation laser light to the final optical unit;
A two-dimensional detector that receives the misalignment detection light reflected by the second dichroic mirror;
Provided is a laser irradiation apparatus for determining whether or not an irradiation laser beam is irradiated on an irradiation target position of an object based on a detection position of a misalignment detection light received by a two-dimensional detector. is there.

In addition, the present invention generates an irradiation laser beam for irradiating an object with the first light source, and generates a misalignment detection light with a wavelength different from that of the irradiation laser beam with the second light source,
The traveling direction of the misalignment detection light generated by the second light source is changed by the first reflecting member,
The laser beam for irradiation and the misalignment detection light whose traveling direction is changed are made incident on the first dichroic mirror, the irradiation laser beam is transmitted and the misalignment detection light is reflected, and both lights are coaxial.
Coaxially irradiated irradiation laser light and misalignment detection light are incident on a second dichroic mirror disposed immediately before the final optical unit for irradiating the irradiation laser light onto the object, and the second dichroic mirror Reflecting the misalignment detection light and transmitting the irradiation laser light, leading only the irradiation laser light to the final optical unit,
A laser irradiation method in which a misalignment detection light reflected by a second dichroic mirror is received by a two-dimensional detector, and an irradiation laser beam guided to the final optical unit is irradiated to an object,
Provided a laser irradiation method for determining whether or not an irradiation laser beam is irradiated on a target irradiation position based on a detection position of a misalignment detection light received by a two-dimensional detector It is.

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
A laser beam for irradiating the sheet laminate is generated by a first light source, and a misalignment detection light having a wavelength different from that of the laser beam for irradiation is generated by a second light source,
The traveling direction of the misalignment detection light generated by the second light source is changed by the first reflecting member,
The laser beam for irradiation and the misalignment detection light whose traveling direction is changed are made incident on the first dichroic mirror, the irradiation laser beam is transmitted and the misalignment detection light is reflected, and both lights are coaxial.
The second dichroic light is incident on a second dichroic mirror disposed immediately before the final optical unit for irradiating the laser beam for irradiation to the sheet laminate, and the coaxial laser light for irradiation and misalignment detection light are incident on the second dichroic mirror. Reflecting the misalignment detection light by the mirror and transmitting the irradiation laser light, leading only the irradiation laser light to the final optical unit,
Receiving the misalignment detection light reflected by the second dichroic mirror with a two-dimensional detector, and irradiating the sheet laminate with the irradiation laser light guided to the final optical unit;
Manufacture of a sheet fusion body in which it is determined whether or not the irradiation position of the sheet laminate is irradiated based on the detection position of the misalignment detection light received by the two-dimensional detector. A method is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the shift | offset | difference of the optical axis of a laser beam can be easily detected, without producing the energy loss of a laser beam even in laser beam irradiation.

FIG. 1 is a schematic view showing an embodiment of a laser irradiation apparatus of the present invention. FIG. 2 is a schematic diagram (corresponding to FIG. 1) showing another embodiment of the laser irradiation apparatus of the present invention. FIG. 3 is a schematic view (corresponding to FIG. 1) showing still another embodiment of the laser irradiation apparatus of the present invention. FIG. 4 is a schematic diagram (corresponding to FIG. 1) showing still another embodiment of the laser irradiation apparatus of the present invention. FIG. 5 is a schematic diagram (corresponding to FIG. 1) showing still another embodiment of the laser irradiation apparatus of the present invention. FIG. 6 is a perspective view showing a pants-type disposable diaper as an example of a sheet fusion product manufactured by the laser irradiation apparatus and the laser irradiation method of the present invention. 7 is a cross-sectional view taken along line VI-VI in FIG. FIG. 8 is a schematic diagram showing a manufacturing process of the pants-type disposable diaper shown in FIG. FIG. 9 is a schematic view 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 an embodiment of the laser irradiation apparatus of the present invention. The laser irradiation apparatus 10 shown in the figure has a first light source 21 that generates an irradiation laser beam 20 that is applied to an irradiation target T. In addition, the irradiation apparatus 10 includes a second light source 22 that generates misalignment detection light 23 having a wavelength different from that of the irradiation laser light 20.

  The movement direction of the misalignment detection light 23 generated by the second light source 22 is changed by the first reflecting member 30 </ b> A including the first mirror 31 and the second mirror 32. The misalignment detection light 23 whose traveling direction has been changed by the first reflecting member 30A is incident on the first dichroic mirror 41 via the first reflecting member 30A. On the other hand, the irradiation laser beam 20 generated by the first light source 20 is directly incident on the first dichroic mirror 41.

  The first dichroic mirror 41 reflects the misalignment detection light 23 incident through the first reflecting member 30A, and transmits the irradiation laser light 20 incident from the first light source 21. 23 is coaxial. “Coaxial” means that the optical axis of the irradiation laser beam 20 is coincident with the optical axis of the positional deviation detection light 23. The “optical axis” refers to the center line of the light beam passing from the light source to the target. In order to make the irradiation laser beam 20 and the displacement detection light 23 coaxial, the incident angles of the irradiation laser beam 20 and the displacement detection light 23 to the first dichroic mirror 41 are set to the first reflecting member 30A. It is necessary to adjust with. Further, whether or not the irradiation laser beam 20 and the positional deviation detection beam 23 are in a coaxial state by the first dichroic mirror 41 is determined downstream of the first dichroic mirror 41 from the first light source 21 to the irradiation target T. If a position having a distance equal to or longer than the optical path length is defined as point A, it varies depending on the wavelength band to be used. For example, it is a sensor in a wide wavelength range that can detect each of two wavelengths. It can be judged by sensing both lights 20 and 23 at a plurality of points in the optical path and making the detection positions the same at each position.

  The dichroic mirror is also called a multilayer optical functional reflecting mirror or dichroic mirror, and is a kind of mirror manufactured using a special optical material. The dichroic mirror has a characteristic of reflecting light of a specific wavelength and transmitting light of other wavelengths. As the first dichroic mirror 41 used in the present embodiment, as described above, a mirror having the property of reflecting the misalignment detection light 23 and transmitting the irradiation laser light 20 is used.

  The laser irradiation device 10 includes a second dichroic mirror 42 in addition to the first dichroic mirror 41. The second dichroic mirror 42 receives the irradiation laser light 20 and the displacement detection light 23 which are made coaxial by the first second dichroic mirror 41. The second dichroic mirror 42 is disposed immediately before the final optical unit 43 for irradiating the irradiation target T with the irradiation laser beam 20. “Arranged immediately before” means that no optical component is interposed between the second dichroic mirror 42 and the final optical unit 43. The “final optical unit” means an optical unit including a lens such as a lens or a mirror or a galvano scanner disposed immediately before the irradiation target T.

  As the final optical unit 43, various types can be adopted depending on the type of the irradiation object T and the purpose of irradiation with the laser beam 20. For example, as will be described later, the irradiation target T includes a thermoplastic resin, and when the irradiation target T in the conveyance process is melted and fused along one direction by irradiation of the laser beam 20, As the final optical unit 43, a galvano scanner provided with an Fθ lens can be used. Further, in the case of a general stage moving laser processing machine, a convex lens having an arbitrary focal length can be used as the final optical unit 43.

  Between the first dichroic mirror 41 and the second dichroic mirror 42, the irradiation laser light 20 and the positional deviation detection light 23 travel in a coaxial state. The irradiation laser beam 20 and the positional deviation detection beam 23 traveling in a coaxial state travel by at least one second reflecting member 30B disposed between the first dichroic mirror 41 and the second dichroic mirror 42. The direction is changed and guided from the first dichroic mirror 41 to the second dichroic mirror. In the present embodiment, the second reflecting member 30B is composed of a plurality of mirror groups 33-36.

  The irradiation laser beam 20 and the misalignment detection beam 23 traveling in a coaxial state on the optical path between the first dichroic mirror 41 and the second dichroic mirror 42 are incident on the second dichroic mirror 42 to be irradiated. The laser beam 20 is separated into the misalignment detection beam 23. For this purpose, as the second dichroic mirror 42, a mirror that reflects the displacement detection light 23 and transmits the irradiation laser light 20 is used. The second dichroic mirror 42 is the same type as the first dichroic mirror 41 as long as it can reflect the misalignment detection light 23 and transmit the irradiation laser light 20. It may be different or different.

  The misalignment detection light 23 reflected by being incident on the second dichroic mirror 42 is received by the two-dimensional detector 44. The two-dimensional detector 44 is composed of an optical sensor having a planar light receiving part. By making the misalignment detection light 23 incident on the planar light receiving section from a direction orthogonal thereto, the light receiving position of the misalignment detecting light 23 in the light receiving section, that is, the light receiving coordinates can be detected.

  As the two-dimensional detector 44, the same one as conventionally used as this kind of optical sensor can be used. For example, as the two-dimensional detector 44, for example, a semiconductor position detection element (PSD) or a charge coupled device (CCD) can be used. The resolution of the two-dimensional detector 44 affects the accuracy of detecting the positional deviation of the irradiation laser beam 20, and the higher the resolution, the higher the accuracy of detecting the positional deviation. The resolution of the two-dimensional detector 44 may be determined according to the beam diameter of the irradiation laser beam 20 irradiated on the irradiation target T and the required accuracy of the apparatus.

  In the laser irradiation apparatus 10 of this embodiment, in addition to the various optical members described above, other optical members may be arranged in the optical path formed by the second reflective member 30B described above as necessary. Good. For example, in the laser irradiation apparatus 10 shown in FIG. 1, a beam expander 45 is disposed as an additional optical member between the fourth mirror 34 and the fifth mirror 35.

A method of irradiating the irradiation target T with the laser beam 20 using the laser irradiation apparatus 10 having the above configuration will be described. First, an irradiation laser beam 20 for irradiating the object T is generated by the first light source 21. At the same time, the misalignment detection light 23 is generated by the second light source 22. As the irradiation laser beam 20, an appropriate one is used according to the type of irradiation object T and the purpose of irradiation. As the first light source 21 of the laser beam 20, a CO ₂ laser, a YAG laser, an LD laser (semiconductor laser). ), YVO ₄ laser, fiber laser or the like can be used.

  On the other hand, the misalignment detection light 23 is not limited to laser light as long as it has a wavelength that can be separated from the irradiation laser light 20 by the first and second dichroic mirrors. For example, a laser diode, a He—Ne laser, a light emitting diode (LED), a halogen light source, or the like can be used as the second light source 22 of the positional deviation detection light 23. When using a light emitting diode (LED) or a halogen light source, it is preferable to adjust the lens system to prevent light from diffusing. When the distance of the optical system is long, it is advantageous to use a laser light source such as a laser diode or a He—Ne laser. Further, the wavelength of the misalignment detection light 23 is preferably in the visible light region of, for example, 400 nm or more and 700 nm or less so that alignment is easy. On the other hand, when a wavelength in the visible light region is used for the irradiation laser beam 20, it is preferable to use a wavelength different from the visible region such as the far infrared region.

  The misalignment detection light 23 generated by the second light source 22 is changed in the traveling direction by the first reflecting member 30 </ b> A composed of the first mirror 31 and the second mirror 32 and is incident on the first dichroic mirror 41. reflect. On the other hand, the irradiation laser beam 20 generated by the first light source 21 directly enters the first dichroic mirror 41 and passes therethrough. As a result, the irradiation laser beam 20 and the positional deviation detection beam 23 are coaxial.

  The irradiation laser beam 20 and the positional deviation detection beam 23 in the coaxial state travel on an optical path formed by the second reflecting member 30B composed of a plurality of mirrors 33-36. If necessary, optical processing such as suppression of aberrations is performed by passing through an optical member disposed in the optical path, for example, a beam expander 45.

  The irradiation laser beam 20 and the positional deviation detection beam 23 that have traveled along the optical path formed by the second reflecting member 30B are then incident on the second dichroic mirror 42. As described above, the second dichroic mirror 42 reflects the irradiation laser light 20 and transmits the irradiation laser light 20, so that the irradiation laser light incident on the second dichroic mirror 42 in a coaxial state is used. 20 and the misalignment detection light 23, the misalignment detection light 23 is reflected by the second dichroic mirror 42 and does not pass through it. The misalignment detection light 23 reflected by the second dichroic mirror 42 is received by a two-dimensional detector 44 arranged in the reflection direction. On the other hand, the irradiation laser beam 20 is not reflected by the second dichroic mirror 42 but passes through it. Then, only the irradiation laser beam 20 is guided to the final optical unit 43.

  The irradiation laser light 20 guided to the final optical unit 43 passes through the lens 43 and is subjected to optical processing such as focusing, and then irradiated toward the irradiation target T. Usually, prior to the main irradiation of the irradiation target T with the laser beam 20, the irradiation is performed in advance for alignment of the irradiated portion, and the alignment of the optical axis of the laser beam 20 is performed. The laser beam 20 is correctly applied to the irradiation target position of the irradiation target T. However, depending on the case, the optical axis aligned in advance may change over time due to the temperature change of the optical member arranged in the laser oscillator or on the optical path, or the laser beam 20 light may change due to the aging of the apparatus 10. The axis may shift. In that case, the irradiation target position of the irradiation target T is not correctly irradiated with the laser beam 20, and the irradiation position is shifted. Whether or not this misalignment has occurred is determined using misalignment detection light 23 reflected by the second dichroic mirror 42 and incident on the two-dimensional detector 44. The specific method is as follows.

  As described above, the two-dimensional detector 44 has a planar light receiving portion (not shown), and the light receiving portion is arranged so as to be orthogonal to the misalignment detection light 23 incident thereon. By making the positional deviation detection light 23 incident on the planar light receiving part from a direction orthogonal thereto, the light receiving position of the positional deviation detection light 23 in the light receiving part, that is, the light receiving coordinates are detected. This light receiving coordinate is referred to as “detected light receiving coordinate”. The detected light receiving coordinates are obtained continuously while the irradiation target T is continuously irradiated with the laser beam 20, or are obtained intermittently at predetermined intervals.

  As described above, prior to the main irradiation of the laser beam 20 to the irradiation object T, prior irradiation is performed for alignment of the irradiated portion, and the optical axis of the laser beam 20 is aligned. At this time, in addition to the laser beam 20, the misalignment detection light 23 is also emitted in a coaxial state, the misalignment detection light 23 is received by the two-dimensional detector 44, and the received light coordinates in the alignment state are obtained. It is detected in advance. These light receiving coordinates are referred to as “standard light receiving coordinates”. Then, the detected light receiving coordinates described above are compared with the standard light receiving coordinates, and if the deviation of the coordinates is within a preset threshold value, the irradiation laser beam 20 is correctly positioned at the planned irradiation position of the object T. Judged to be irradiated. Conversely, if the deviation between the detected light receiving coordinates and the standard light receiving coordinates exceeds a threshold value, it is determined that the irradiation laser beam 20 is not correctly irradiated on the irradiation target position of the object T, and an alert is generated. Thus, it is possible to inform the user of the necessity of adjusting the optical axis.

The detected light receiving coordinates and the standard light receiving coordinates are both two-dimensional coordinates. When the detected light receiving coordinates are (x _d , y _d ) and the standard light receiving coordinates are (x _s , y _s ), the deviation between the two coordinates is within the threshold value. If the threshold value is L, √ { ^{_{(x d -x s) 2 +}} (y d -y s) 2} refers to a <L. On the other hand, the difference between the two coordinates exceeding the threshold means that {L (x _d −x _s ) ² + (y _d −y _s ) ² } ≧ L, where L is the threshold value.

  According to the above method, since the deviation of the optical axis of the irradiation laser light 20 is detected by using the positional deviation detection light 23 which is light different from the irradiation laser light 20, the irradiation laser light 20 It is possible to easily detect the deviation of the optical axis of the irradiation laser beam 20 without causing any energy loss.

  When it is determined that a deviation has occurred in the optical axis of the irradiation laser beam 20, a reflection member installed in the optical path of the irradiation laser beam 20, particularly between the first dichroic mirror 41 and the second dichroic mirror 42. Alignment is performed by adjusting the direction of each mirror 33-36 constituting the second reflecting member 30B. When this alignment is performed, it is generally difficult to determine which optical system has caused the optical axis shift. Therefore, when using a plurality of optical systems, it is often necessary to realign from the most upstream side. However, in the present invention, a laser irradiation apparatus and a laser irradiation method capable of easily restoring the alignment state of the optical axis by using an optical axis adjustment assisting tool for assisting the optical axis adjustment of the irradiation laser beam 20. Is also provided. The embodiment is shown in FIG.

  The laser irradiation apparatus 10A according to the embodiment shown in FIG. 2 is such that the laser irradiation apparatus 10 shown in FIG. Therefore, in this embodiment, the optical axis adjustment assisting tool 50 and the optical axis adjustment method of the irradiation laser beam 20 using the same will be mainly described, and other points are shown in the embodiment shown in FIG. The description regarding is also applied to this embodiment.

  The optical axis adjustment assisting tool 50 includes a reflecting member 51 made of an optical member such as a mirror and a two-dimensional detector 52 accommodated in a housing 53, whereby the reflecting member 51 and the two-dimensional detector are arranged. 52 has an integrated structure. The optical axis adjustment assisting tool 50 can be detachably disposed at a position between at least one second reflecting member 30B and an optical member located immediately downstream of the second reflecting member 30B. “Between at least one second reflecting member 30B and an optical member located immediately downstream of the second reflecting member 30B” is 1 when the second reflecting member 30B is composed of one reflecting member. It means between the two reflecting members and the optical member located immediately downstream thereof. On the other hand, when the second reflecting member 30B is composed of two or more reflecting members, any one second reflecting member among the plurality of second reflecting members and the second reflecting member immediately. It means between another second reflecting member located downstream, or between the second reflecting member located on the most downstream side of the plurality of reflecting members and the optical member located immediately downstream thereof. I mean. Since the second reflecting member 30B in the laser irradiation apparatus 10A is composed of a plurality of mirrors 33-36, the optical axis adjustment assisting tool 50 is provided between two mirrors 33-36 adjacent to each other upstream and downstream. It can be detachably disposed at a position or a position between the mirror 36 and the second dichroic mirror 42. In the embodiment shown in FIG. 2, a state in which the optical axis adjustment assisting tool 50 is arranged at a position between the third mirror 33 and the fourth mirror 34 is shown.

  The reflecting member 51 in the optical axis adjustment assisting tool 50 is coaxial with the irradiation laser light 20 in a state where the optical axis adjustment assisting tool 50 is disposed at a position between the third mirror 33 and the fourth mirror 34. In addition, the optical path is switched within the optical path of the misalignment detection light 23 and guided to the two-dimensional detector 52 in the optical axis adjustment auxiliary tool 50. Therefore, when the optical axis adjustment assisting tool 50 is disposed in the optical path, the irradiation laser beam 20 and the positional deviation detection light 23 that are coaxial with the dichroic mirror 41 travel through the third mirror 33 and the reflecting member 51. The direction is changed and guided to the two-dimensional detector 52 so that it does not reach the second reflecting member 30B after the fourth mirror 34.

  The optical axis adjustment of the irradiation laser beam 20 using the optical axis adjustment auxiliary tool 50 is performed according to the following procedure. Prior to the main irradiation of the irradiation target T with the laser beam 20, pre-irradiation is performed to align the irradiation position of the laser beam 20 on the target T, and the first dichroic mirror 41 and the second dichroic mirror 42 are aligned. Adjustment is performed so that the irradiation laser beam 20 and the positional deviation detection beam 23 that are coaxial in the optical path between them are aligned in advance. This adjustment is performed by adjusting the direction of each mirror 33-36 which comprises the 2nd reflective member 30B. When the alignment is completed, the optical axis adjustment assisting tool 50 is disposed at a position between the third mirror 33 and the fourth mirror 34 which are one of the second reflecting members 30B under this aligned state. The arrangement position of the optical axis adjustment assisting tool 50 is preferably a position closer to the fourth mirror 34 between the third mirror 33 and the fourth mirror 34, since the deviation of the optical axis can be detected more sensitively. (The same applies between the fourth mirror 34 and the fifth mirror 35 described below, between the fifth mirror 35 and the sixth mirror 36, and between the sixth mirror 36 and the second dichroic mirror 42). At the same time, only the misalignment detection light 23 is generated by the second light source 22. The generated misalignment detection light 23 passes through the first and second mirrors 31 and 32 constituting the first reflecting member 30A, the first dichroic mirror 41, and the third mirror 33 constituting the second reflecting member 30B. The light enters the optical axis adjustment aid 50. The misalignment detection light 23 incident on the optical axis adjustment assisting tool 50 is reflected by the reflecting member 51 disposed in the optical axis adjustment assisting tool 50 and its traveling direction is changed. The light is received by the two-dimensional detector 52 arranged inside. In this way, the light receiving coordinates at the position between the third mirror 33 and the fourth mirror 34 in the alignment state are detected in advance and stored. This light receiving coordinate is referred to as “third mirror standard light receiving coordinate”.

  If it is determined that the optical axis of the irradiation laser beam 20 is deviated as a result of the comparison between the detected light receiving coordinates by the two-dimensional detector 44 described above and the standard light receiving coordinates, the irradiation laser beam 20 and the displacement detection light 23 are stopped, and the optical axis adjustment assisting tool 50 is disposed at a position between the third mirror 33 and the fourth mirror 34 which are one of the second reflecting members 30B. At the same time, only the misalignment detection light 23 is generated by the second light source 22. The generated misalignment detection light 23 is received by the two-dimensional detector 52 disposed in the optical axis adjustment auxiliary tool 50. Thereby, the light receiving coordinates which are the light receiving position of the positional deviation detecting light 23 in the light receiving portion of the two-dimensional detector 52 are detected. This light receiving coordinate is referred to as “third mirror detected light receiving coordinate”. The third mirror detection light receiving coordinate is obtained continuously while adjusting the optical axis of the irradiation laser beam 20, or is obtained intermittently at predetermined intervals.

  The adjustment of the optical axis of the irradiation laser beam 20 is performed by comparing the third mirror detection light receiving coordinates with the third mirror standard light receiving coordinates stored in advance. Specifically, a second mirror disposed immediately upstream of the optical axis adjustment assisting tool 50 so that the value of the third mirror detection light receiving coordinate returns to the value of the third mirror standard light receiving coordinate stored in advance. The direction of the third mirror 33 that is the reflecting member 30B is adjusted. This adjustment can be done manually or mechanically automated. As described above, since the irradiation laser beam 20 and the misregistration detection beam 23 are already aligned coaxially, if this confirmation or adjustment is performed with respect to the misregistration detection beam 23, the irradiation laser beam is consequently obtained. By identifying which optical system causes the positional deviation of the 20 optical axes, and adjusting only that optical system, the alignment state that has been adjusted in advance is restored. Therefore, after that, if the laser irradiation apparatus 10 is operated in a normal state, the irradiation laser beam 20 is appropriately irradiated to the irradiation target position of the object T. As described above, according to the present embodiment, it is possible to identify which optical system is causing the positional deviation by sequentially examining from the upstream side, and other optical systems in which no deviation occurs are unnecessary. There is an advantage that only the optical system can be adjusted and restored without moving it.

  In the optical axis adjustment of the irradiation laser beam 20 using the optical axis adjustment assisting tool 50, it is advantageous that the optical axis adjustment assisting tool 50 can be easily and detachably disposed in the optical path. In addition to this, it is also advantageous to prevent misalignment in the arrangement state. From these viewpoints, the positioning member capable of positioning when the optical axis adjustment assisting tool 50 is disposed at a position between the second reflecting member 30B and the optical member positioned downstream of the second reflecting member 30B is provided as the first member. It is preferable to provide the optical path between the dichroic mirror 41 and the second dichroic mirror 42. In the present embodiment, a plurality of positioning pins 54a to 54d are projected from a support plate (not shown) having a plane parallel to the paper surface in FIG. 2, and optical axis adjustment assistance is performed using these positioning pins 54a to 54d. The tool 50 is detachably held in the optical path.

  By the above method, the deviation of the optical axis generated in the irradiation laser beam 20 is corrected, and the optical axis of the irradiation laser beam 20 is brought into the alignment state in the optical path between the first dichroic mirror 41 and the third mirror 33. Can be restored. However, in some cases, there is no deviation in the optical axis of the irradiation laser beam 20 between the first dichroic mirror 41 and the third mirror 33, but the irradiation laser beam in the optical path downstream of the third mirror 33. There may be a deviation in the 20 optical axes. In this case, after performing the operation shown in FIG. 2 to bring the optical axis of the irradiation laser beam 20 into the alignment state in the optical path between the first dichroic mirror 41 and the third mirror 33, as shown in FIG. The arrangement position of the optical axis adjustment assisting tool 50 may be arranged at a position between the fourth mirror 34 and the fifth mirror 35, and the same operation as that shown in FIG. Details are as follows.

  First, similarly to the operation shown in FIG. 2, prior to the main irradiation of the laser beam 20 to the irradiation target T, the irradiation is performed in advance for alignment of the irradiation position, and the first dichroic mirror 41 and the second dichroic mirror are performed. In the optical path to 42, adjustment is performed so that the irradiation laser beam 20 and the displacement detection light 23 in a coaxial state are aligned in advance. When the alignment is completed, the optical axis adjustment assisting tool 50 is disposed at a position between the fourth mirror 34 and the fifth mirror 35 under the aligned state. At the same time, only the misalignment detection light 23 is generated by the second light source 22. The generated misalignment detection light 23 enters the optical axis adjustment aid 50. The misalignment detection light 23 incident on the optical axis adjustment assisting tool 50 is received by a two-dimensional detector 52 disposed in the optical axis adjustment assisting tool 50. In this way, the light receiving coordinates at the position between the fourth mirror 34 and the fifth mirror 35 in the alignment state are detected in advance and stored. This light receiving coordinate is referred to as “fourth mirror standard light receiving coordinate”.

  When it is determined that a deviation has occurred in the optical axis of the irradiation laser beam 20 while the laser irradiation apparatus 10A is operated and the irradiation laser beam 20 and the positional deviation detection beam 23 are irradiated, irradiation is performed. Irradiation of the laser beam 20 and the misalignment detection light 23 is stopped, and the optical axis adjustment assisting tool 50 is disposed at a position between the fourth mirror 34 and the fifth mirror 35. At the same time, only the misalignment detection light 23 is generated by the second light source 22. The generated misalignment detection light 23 is received by the two-dimensional detector 52 disposed in the optical axis adjustment auxiliary tool 50. As a result, a fourth mirror detection light receiving coordinate which is a light receiving coordinate of the light receiving position of the positional deviation detecting light 23 in the light receiving unit of the two-dimensional detector 52 is obtained. Then, the optical axis of the irradiation laser beam 20 is adjusted by comparing the fourth mirror detection light receiving coordinates with the previously stored fourth mirror standard light receiving coordinates. Specifically, the direction of the fourth mirror 34 is adjusted so that the value of the fourth mirror detection light receiving coordinate returns to the value of the fourth mirror standard light receiving coordinate stored in advance.

  In the operation shown in FIG. 3, the optical axis adjustment auxiliary tool 50 is disposed between the fourth mirror 34 and the fifth mirror 35, and irradiation is performed in the optical path between the first dichroic mirror 41 and the fourth mirror 34. 4, the operation shown in FIG. 4 is performed by placing an optical axis adjustment auxiliary tool 50 between the fifth mirror 35 and the sixth mirror 36. The optical axis of the irradiation laser beam 20 is aligned in the optical path from the first dichroic mirror 41 to the fifth mirror 35. When the operation shown in FIG. 4 is performed, prior to that, the operation shown in FIG. 2 is performed to adjust the optical axis of the irradiation laser beam 20 to the alignment state in the optical path between the first dichroic mirror 41 and the third mirror 33. Subsequently, the operation shown in FIG. 3 is performed to adjust the optical axis of the irradiation laser beam 20 in the alignment state in the optical path between the third mirror 33 and the fourth mirror 34. Thereafter, the operation shown in FIG. 4 is performed in the same manner as the operation shown in FIG.

  When the alignment state of the optical axis of the irradiation laser beam 20 is restored by the method shown in FIGS. 2 to 4 using the optical axis adjustment assisting tool 50 described above, prior to that, the second light source 22 of the misalignment detection light 23 is used. In the optical path from the second reflecting member 30B to the second reflecting member 30B, specifically, in the optical path from the second light source 22 to the third mirror 33, the optical axis of the misalignment detection light 23 may be in an aligned state. preferable. By performing this operation, it is possible to reliably restore the optical axis of the irradiation laser beam 20 in which the alignment state is shifted. Specifically, the following operation is performed.

  First, prior to the main irradiation of the irradiation target T with the irradiation laser beam 20, pre-irradiation is performed for alignment of the irradiation position of the laser beam 20 on the target T, and the first dichroic mirror 41 and the second dichroic are aligned. Adjustment is performed so that the irradiation laser light 20 and the positional deviation detection light 23 in the coaxial state in the optical path to the mirror 42 are aligned in advance. When the alignment is completed, the optical axis adjustment assisting tool 50 is disposed at a position between the second light source 22 and the first mirror 31, as shown in FIG. At the same time, the second light source 22 generates misalignment detection light 23. The generated misalignment detection light 23 is received by a two-dimensional detector 52 disposed in the optical axis adjustment aid 50. In this way, the light receiving coordinates at the position between the second light source 22 and the first mirror 31 in the alignment state are detected in advance and stored. The light receiving coordinates are referred to as “first mirror standard light receiving coordinates”.

  When the first mirror standard light receiving coordinates can be acquired, the optical axis adjustment auxiliary tool 50 is removed from the apparatus 10A, the laser light irradiation apparatus 10A is operated, and the irradiation target T is irradiated with the irradiation laser light 20. As a result of comparison between the detected light receiving coordinates by the two-dimensional detector 44 and the standard light receiving coordinates during the main irradiation of the laser light 20, it was determined that a deviation occurred in the optical axis of the irradiation laser light 20. In this case, the irradiation of the irradiation laser beam 20 and the positional deviation detection light 23 is stopped, and the optical axis adjustment auxiliary tool 50 is placed at a position between the second light source 22 and the first mirror 31 as shown in FIG. Deploy. At the same time, only the misalignment detection light 23 is generated by the second light source 22. The generated misalignment detection light 23 is received by the two-dimensional detector 52 disposed in the optical axis adjustment auxiliary tool 50. Thereby, the light receiving coordinates which are the light receiving position of the positional deviation detecting light 23 in the light receiving portion of the two-dimensional detector 52 are detected. This light receiving coordinate is referred to as “first mirror detected light receiving coordinate”.

  The adjustment of the optical axis of the misalignment detection light 23 is performed by comparing the first mirror detection light receiving coordinates with the first mirror standard light receiving coordinates stored in advance. Specifically, the direction of the second light source 22 is adjusted so that the value of the first mirror detection light receiving coordinate returns to the value of the first mirror standard light receiving coordinate stored in advance.

  The same operation as described above is performed using the optical axis adjustment assisting tool 50 between the first mirror 31 and the second mirror 32, between the second mirror 32 and the first dichroic mirror 41, and between the first dichroic mirror 41 and the third mirror. This is also performed at a position between the mirror 33 and the direction of the first mirror 31, the second mirror 32, and the first dichroic mirror is adjusted. As a result, the optical axis of the misalignment detection light 23 can be brought into an alignment state in the optical path from the second light source 22 to the third mirror 33. Thereafter, the operations shown in FIGS. 2 to 4 are performed to bring the optical axis of the irradiation laser beam 20 into an alignment state.

  The laser irradiation apparatus and laser irradiation method of the present invention can be applied to various irradiation objects T. 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.

  6 and 7 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. A pants-type disposable in which both side edges of the body 3 and both side edges of the exterior body in the back side 1B are joined to form a pair of side seal parts 4, a waist opening 8 and a pair of leg openings 9. A 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. 8 and 9 according to the method for manufacturing a sheet fusion product, in which a seal edge portion is formed by fusing the sealant.

  As shown in FIG. 8, 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 waist elastic member 6 continuously or intermittently by an adhesive coating machine (not shown), and the leg elastic member 7 is These 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. 8, the belt-shaped outer layer sheet 3a and the belt-shaped outer layer sheet 3a in which the waist elastic member 5, the waistline elastic member 6 and the leg elastic member 7 are sandwiched between the pair of nip rolls 111, 111 in a stretched state. 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. 8, 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 strip-shaped outer package. It is intermittently supplied and fixed on the inner layer sheet 32 constituting the body 3. The adhesive for fixing the absorbent main body may be applied in advance to the position where the absorbent main body 2 is to be arranged in the inner layer sheet 32 instead of the absorbent main body 2.

  Subsequently, as shown in FIG. 8, a leg hole LO ′ is formed inside the annular portion surrounded by the leg elastic member 7 in the belt-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 hole is formed after the absorbent main body 2 is arranged on the belt-shaped outer package 3, but the leg hole 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. 8, 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 main body 2. After fixing both longitudinal ends of 2, the exterior body 3 is folded in half in the width direction together with the absorbent main body 2. In this way, the diaper continuous body 1 'is obtained.

  The diaper continuous body 1 ′ thus manufactured is irradiated with laser light using the laser bonding apparatus 120 shown in FIG. 9 including the laser irradiation apparatus of the present invention, so that the pair of side seal portions 4, 4 is formed. The underpants-type disposable diaper 1 as a sheet fusion body comprising the exterior body 3 having the outer body 3 is continuously manufactured.

  The laser bonding apparatus 120 will be described. As shown in FIG. 9, the apparatus 120 includes a hollow cylindrical roll 123 having a cylindrical support member 121 that is rotationally driven in the direction of arrow A, and the support member 121. An irradiation head 135 that has a lens 134 that condenses the laser light 20 and is disposed in the hollow portion, an endless pressure belt 124 as a pressure unit, and a plurality of rotations that rotate in a state where the pressure belt 124 is bridged. Belt type pressurizing device 126 provided with rolls 125a, 125b, and 125c. The laser type bonding apparatus 120 includes a tension adjusting mechanism (not shown) that can adjust the tension of the pressure belt 124 wound around the outer peripheral surface of the annular support member 121, that is, the peripheral surface portion of the cylindrical roll 123. By the adjustment, the pressure applied to the diaper continuous body 1 ′ can be appropriately adjusted by the support member 121 and the pressure belt 124.

  As the pressure belt 124, a metal or resin belt having heat resistance capable of withstanding the heat generated during processing can be used. For example, the pressure belt 124 is made of a metal material such as iron, aluminum, and stainless steel. Further, as the pressure belt 124, a belt that does not have the transparency of the laser beam 20 irradiated to the diaper continuous body 1 ′ that is a workpiece is usually used, but the belt having the transparency is used. You can also.

  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 122 and 122 that form both left and right edge portions 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 122, and has heat resistance such as a metal material such as iron, aluminum, stainless steel, copper, or ceramics. Made of material.

  The support member 121 has a slit-shaped opening 127 that penetrates the support member 21 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. 9, so that the opening 127 extends in the circumferential direction of the cylindrical support member 121. A plurality are formed at predetermined intervals. The support member 121 allows the laser light 20 to pass through the opening 127, but does not transmit the laser light 20 at portions 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 the pair of frame bodies 122, 122 at a predetermined interval in the circumferential direction of the frame body 122. Can be mentioned. In the method 2), the interval between two adjacent members is a slit-shaped opening 127.

  An irradiation head 135 that irradiates the laser beam 20 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 head 135 is provided with a lens 134 that condenses the laser light 20. The irradiation head 135 includes a galvano scanner that freely scans the laser beam 20, that is, a device having a mirror on the motor shaft. The irradiation head 135 is a mechanism for moving the laser beam 20 forward and backward in a direction parallel to the rotation axis of the cylindrical roll 123, that is, a direction indicated by a symbol X in FIG. A mechanism for moving the irradiation point in the circumferential direction of the cylindrical roll 123, a mechanism for making the spot diameter of the laser light 20 constant on the circumferential surface of the cylindrical roll 123, and the like. By having such a configuration, the irradiation head 135 can arbitrarily move the irradiation point of the laser light 20 in both the circumferential direction of the cylindrical roll 123 and the direction orthogonal to the circumferential direction. This irradiation head 135 corresponds to the final optical unit 43 shown in FIGS.

  When the diaper 1 is manufactured using the laser-type bonding apparatus 120 having the above-described configuration, the peripheral surface of the cylindrical roll 123 is formed on one surface of the diaper continuous body 1 ′ while the laser light 20 The diaper continuum 1 ′ having a slit-shaped opening 127 through which can pass through and abutting on the outer surface of the support member 121 and being in a pressurized state from the support member 121 side through the opening 27. By irradiating the light 20, the diaper continuum 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 to form the side seal portion 4. Form.

Whether or not the laser beam 20 is appropriately irradiated to the irradiation planned position P (see FIG. 9) of the laser beam 20 in the diaper continuous body 1 ′ during the formation of the side seal portion 4
This can be determined by the operation shown in FIG. When it is determined that the irradiation laser beam 20 is not irradiated at the irradiation scheduled position P, the light of the irradiation laser beam 20 is obtained by the operation shown in FIGS. Align the axes.

  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. 6 to 9, the laser irradiation apparatus and the laser irradiation method 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.

10, 10A Laser irradiation apparatus 20 Irradiation laser light 21 First light source 22 Second light source 23 Position shift detection light 30A First reflection member 30B Second reflection member 31 First mirror 32 Second mirror 33 Third mirror 34 Fourth Mirror 35 Fifth mirror 36 Sixth mirror 41 First dichroic mirror 42 Second dichroic mirror 43 Final optical unit 44 Two-dimensional detector 50 Optical axis adjustment auxiliary tool 51 Reflective member 52 Two-dimensional detector T Irradiation target

Claims (5)

A laser beam for irradiating an object is generated by the first light source, and a misalignment detection light having a wavelength different from that of the laser beam for irradiation is generated by the second light source.
The traveling direction of the misalignment detection light generated by the second light source is changed by the first reflecting member,
The laser beam for irradiation and the misalignment detection light whose traveling direction is changed are made incident on the first dichroic mirror, the irradiation laser beam is transmitted and the misalignment detection light is reflected, and both lights are coaxial.
Coaxially irradiated irradiation laser light and misalignment detection light are incident on a second dichroic mirror disposed immediately before the final optical unit for irradiating the irradiation laser light onto the object, and the second dichroic mirror Reflecting the misalignment detection light and transmitting the irradiation laser light, leading only the irradiation laser light to the final optical unit,
A laser irradiation method in which a misalignment detection light reflected by a second dichroic mirror is received by a two-dimensional detector, and an irradiation laser beam guided to the final optical unit is irradiated to an object,
The first dichroic mirror and the second dichroic are connected to the second reflecting member that changes the traveling direction of the coaxially irradiated laser beam and the positional deviation detection light emitted from the first dichroic mirror and leads them to the second dichroic mirror. Under the condition of being arranged between the mirrors, irradiate the irradiation laser light and the position shift detection light in a coaxial state,
Based on the detection position of the misalignment detection light received by the two-dimensional detector, determine whether or not the irradiation laser beam is irradiated on the target irradiation position of the object ,
When it is determined that the irradiation laser beam is not irradiated on the target irradiation position of the object, the step of adjusting the optical axis of the irradiation laser beam by adjusting the direction of the mirror constituting the second reflecting member is performed,
Prior to the step of adjusting the optical axis of the irradiation laser light, the step of adjusting the optical axis of the misalignment detection light using the optical axis adjustment assisting tool in the optical path from the second light source to the second reflecting member. And
The optical axis adjustment auxiliary tool has a structure in which the reflecting member and the two-dimensional detector are integrated, and can be detachably disposed at a position between the second light source and the second reflecting member.
The reflecting member in the optical axis adjustment assisting tool is positioned in the optical path of the misalignment detection light in a state where the optical axis adjustment assisting tool is disposed at a position between the second light source and the second reflecting member. The optical path is switched and guided to the two-dimensional detector in the optical axis adjustment aid.
Prior to performing the step of adjusting the optical axis of the misalignment detection light, the irradiation laser beam and misalignment detection light that are coaxial in the optical path between the first dichroic mirror and the second dichroic mirror are aligned in advance. In this state, the optical axis adjustment assisting tool is arranged at a position between the second light source and the second reflecting member, and only the positional deviation detection light is generated, and this is detected by the two-dimensional detection of the optical axis adjustment assisting tool. Received in advance, and stored in advance the detection position of the misalignment detection light in the aligned state,
In the step of adjusting the optical axis of the misalignment detection light, when it is determined that the irradiation laser beam is not irradiated on the irradiation target position of the object, between the second light source and the second reflecting member, An optical axis adjustment assisting tool is disposed at the position, and only a positional deviation detection light is generated. This light is received by the two-dimensional detector of the optical axis adjustment assisting tool, and the optical path from the second light source to the second reflecting member is aligned. Then, the laser irradiation method for returning the detection position of the misalignment detection light received by the two-dimensional detector to the pre-stored detection position of the misalignment detection light in the aligned state . In the step of adjusting the optical axis of the irradiating laser beam, have use optical axis adjustment aid for the assistance of optical axis adjustment of the irradiation laser beam,
Optical axis adjustment aid, positioned between the reflective member and having a two-dimensional detector and is integrated structure, and a second reflecting member, the optical member located immediately downstream of the second reflecting member It can be detachably placed on the
The reflecting member in the optical axis adjustment aid, and the optical axis adjusting aid is a second reflecting member, in a state arranged at a position between the optical member located immediately downstream of the second reflecting member, coaxial Is positioned in the optical path of the irradiation laser light and the misalignment detection light in the state, is switched to the optical path, and is guided to the two-dimensional detector in the optical axis adjustment assisting tool,
Prior to performing the step of adjusting the optical axis of the irradiating laser beam are previously aligned irradiated laser beam and the positional shift detection light coaxial state light path between the first dichroic mirror and the second dichroic mirror state and to keep the optical axis adjusting aid and the second reflecting member to generate only the positional deviation detecting light with disposed at a position between the optical member located immediately downstream of the second reflecting member, which Is received by the two-dimensional detector of the optical axis adjustment auxiliary tool, and the detection position of the misalignment detection light in the aligned state is stored in advance,
In the step of adjusting the optical axis of the irradiation laser beam, when it is determined that the irradiation laser beam is not irradiated to the irradiation target position of the object, the second reflecting member and the second reflecting member immediately It is generated only positional deviation detecting light with arranging the optical axis adjustment aid to the position between the optical member located downstream, second reflection with receiving this two-dimensional detector of the optical axis adjustment aid Aligning the optical path from the member to the second reflecting member , and detecting the position of the position detection light received by the two-dimensional detector in a previously stored alignment state The laser irradiation method according to claim 1 , wherein the laser is returned to the light detection position. 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,
A laser beam for irradiating the sheet laminate is generated by a first light source, and a misalignment detection light having a wavelength different from that of the laser beam for irradiation is generated by a second light source,
The traveling direction of the misalignment detection light generated by the second light source is changed by the first reflecting member,
The laser beam for irradiation and the misalignment detection light whose traveling direction is changed are made incident on the first dichroic mirror, the irradiation laser beam is transmitted and the misalignment detection light is reflected, and both lights are coaxial.
The second dichroic light is incident on a second dichroic mirror disposed immediately before the final optical unit for irradiating the laser beam for irradiation to the sheet laminate, and the coaxial laser light for irradiation and misalignment detection light are incident on the second dichroic mirror. Reflecting the misalignment detection light by the mirror and transmitting the irradiation laser light, leading only the irradiation laser light to the final optical unit,
Receiving the misalignment detection light reflected by the second dichroic mirror with a two-dimensional detector, and irradiating the sheet laminate with the irradiation laser light guided to the final optical unit;
The first dichroic mirror and the second dichroic are connected to the second reflecting member that changes the traveling direction of the coaxially irradiated laser beam and the positional deviation detection light emitted from the first dichroic mirror and leads them to the second dichroic mirror. Under the condition of being arranged between the mirrors, irradiate the irradiation laser light and the position shift detection light in a coaxial state,
Based on the detection position of the misalignment detection light received by the two-dimensional detector, determine whether the irradiation laser beam is irradiated to the irradiation position of the sheet laminate ,
When it is determined that the irradiation laser beam is not irradiated to the irradiation position of the sheet laminate, the step of adjusting the optical axis of the irradiation laser beam by adjusting the direction of the mirror constituting the second reflecting member is performed. ,
Prior to the step of adjusting the optical axis of the irradiation laser light, the step of adjusting the optical axis of the misalignment detection light using the optical axis adjustment assisting tool in the optical path from the second light source to the second reflecting member. And
The optical axis adjustment auxiliary tool has a structure in which the reflecting member and the two-dimensional detector are integrated, and can be detachably disposed at a position between the second light source and the second reflecting member.
The reflecting member in the optical axis adjustment assisting tool is positioned in the optical path of the misalignment detection light in a state where the optical axis adjustment assisting tool is disposed at a position between the second light source and the second reflecting member. The optical path is switched and guided to the two-dimensional detector in the optical axis adjustment aid.
Prior to performing the step of adjusting the optical axis of the misalignment detection light, the irradiation laser beam and misalignment detection light that are coaxial in the optical path between the first dichroic mirror and the second dichroic mirror are aligned in advance. In this state, the optical axis adjustment assisting tool is arranged at a position between the second light source and the second reflecting member, and only the positional deviation detection light is generated, and this is detected by the two-dimensional detection of the optical axis adjustment assisting tool. Received in advance, and stored in advance the detection position of the misalignment detection light in the aligned state,
In the step of adjusting the optical axis of the misalignment detection light, when it is determined that the irradiation laser beam is not irradiated on the irradiation target position of the object, between the second light source and the second reflecting member, An optical axis adjustment assisting tool is disposed at the position, and only a positional deviation detection light is generated. This light is received by the two-dimensional detector of the optical axis adjustment assisting tool, and the optical path from the second light source to the second reflecting member is aligned. Then, the sheet fusion for returning the detection position of the misalignment detection light received by the two-dimensional detector to the pre-stored detection position of the misalignment detection light in the aligned state Body manufacturing method . 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 3 . 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 the laser beam to a predetermined portion of the folded strip-shaped exterior body, the band-shaped exterior body is divided and the side seal portion is formed at the same time. The method for producing an absorbent article according to claim 4 , wherein the sheet fusion body is used.

Images