JP7030914B1 - Manufacturing method of sheet-shaped member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stable method for manufacturing a sheet-like member capable of improving the inspection accuracy of a coating state of a coating layer formed on a base sheet in a production line. SOLUTION: This is a method for manufacturing a sheet-like member, in which a step of forming a coating layer 52 on a base sheet 51 being transferred in one direction and a vertical line LP with respect to the surface of the coating layer at an inspection position of the coating layer. The step of irradiating the coating layer at the inspection position with a plurality of pattern lights from an oblique direction and the coating layer at the inspection position are imaged from another diagonal direction different from the diagonal direction with respect to the vertical line. A step of extracting and synthesizing positive reflection components from a plurality of images acquired in the step of imaging to generate an inspection image, and a step of setting at least one inspection region for the inspection image, and the above-mentioned step. Manufacture of a sheet-shaped member including a step of calculating a measured value indicating a coated state of a coated layer and a step of comparing the measured value with a preset threshold value to determine whether or not the coated state of the coated layer is good or bad. Method. [Selection diagram] Fig. 1

Description

The present invention relates to a method for manufacturing a sheet-like member in which a coating layer is provided on a base sheet.

Conventionally, various techniques for forming a coating layer on a base material and performing an in-line inspection to manufacture a member having a desired coating layer have been proposed.

For example, Patent Document 1 describes an apparatus for inspecting the quality of a plurality of hot melt adhesives applied to a box body. The hot-melt adhesive contains a light-emitting material that emits light by ultraviolet light, and the apparatus irradiates the hot-melt adhesive-coated surface of the box with ultraviolet light to take an image from a vertical direction. Based on the captured image, the quality of the hot melt is determined by obtaining the relative ratio or difference of the number of pixels between the coated portions of the hot melt adhesive.

Patent Document 2 describes an apparatus for inspecting the surface state of a transparent coating layer provided on a substrate. The device includes a light source that irradiates the surface of the coating layer with irradiation light at an angle that is totally reflected, and an observation device that receives the reflected light that is totally reflected by the irradiation light at a position facing the light source. The irradiation angle (angle of the vertical line with respect to the coating layer) of the irradiation light is 85 ° to 87 °, so that the light is incident on the surface of the coating layer almost in parallel.

Patent Document 3 describes an adhesive coating portion extraction method for acquiring and inspecting two types of edge data of an adhesive coated on a substrate. In this method, the object to be inspected is irradiated with light by two ring lights having different heights installed above the object to be inspected. Further, an image is taken from above to acquire image data, and the above two types of edge data are acquired based on the image data.
Patent Document 4 describes a method for inspecting a transparent adhesive applied to a rough surface of a substrate. In this inspection method, light is irradiated in the horizontal direction along the surface of the substrate, and the diffusely reflected light of the irradiated light is used to perform imaging from above in the vertical direction.

Japanese Unexamined Patent Publication No. 2015-13753 Japanese Unexamined Patent Publication No. 2003-247950 Japanese Unexamined Patent Publication No. 2006-162274 Japanese Unexamined Patent Publication No. 2011-102759

The sheet-like member obtained by providing the coating layer on the base sheet is incorporated into various articles to exhibit desired performance. From the viewpoint of maintaining its performance, it is necessary to uniformly form the coating layer at a predetermined position. The formation of the coating layer is generally performed continuously on a production line for continuously transporting (transferring) the base material sheet, and it is required to accurately detect the quality of the formation of the coating layer in-line. .. In addition, there are various coating materials for the coating layer, and inspection and control that can handle all of them are required.
In this respect, the technique described in Patent Document 1 cannot inspect a hot melt adhesive that does not contain a light emitting material that emits light by ultraviolet light, and the inspection target is limited. In addition, strong ultraviolet light is required for the inspection, and there are restrictions on the realization of a good inspection.
In the inspection technique described in Patent Document 2 using total reflected light without using ultraviolet light, it is necessary that not only the irradiation angle of the irradiation light but also the imaging angle is almost parallel to the surface of the coating layer. However, in the production line, it is necessary to avoid contact between the continuously transported object to be processed and the lighting or the imaging device, and it is often difficult to optimize the conditions such as the imaging angle and the irradiation angle. Even if it can be optimized, there is a possibility of erroneous detection depending on the coating state because the difference in shade between the region of the coating layer and the region of the base material other than that on the image is not sufficiently obtained. The problem that the difference in shade is not sufficiently obtained is the same in the inspection technique using diffuse reflected light described in Patent Document 4. Further, since only the edge data of the adhesive can be extracted by the technique described in Patent Document 3, it is difficult to grasp the coating state in the region of the coating layer.

In view of the above points, the present invention relates to a method for manufacturing a stable sheet-like member capable of improving the inspection accuracy of the coating state of the coating layer formed on the base sheet in the production line.

The present invention is a method for manufacturing a sheet-like member, in which a step of forming a coating layer on a base sheet being transferred in one direction and a diagonal direction with respect to a perpendicular line with respect to the coating layer surface at an inspection position of the coating layer. A step of irradiating a plurality of pattern lights toward the coating layer at the inspection position, and a step of imaging the coating layer at the inspection position from another diagonal direction different from the diagonal direction with respect to the vertical line. A step of extracting and synthesizing a normal reflection component from a plurality of images acquired in the step of imaging to generate an inspection image, and a step of setting at least one inspection region for the inspection image and setting the coating layer. Provided is a method for manufacturing a sheet-shaped member, which comprises a step of calculating a measured value indicating a coated state and a step of comparing the measured value with a preset threshold value to determine the quality of the coated state of the coated layer. do.

Further, the present invention is a sheet-shaped member manufacturing apparatus for a coating device for forming a coating layer on a base sheet being transferred in one direction and a vertical line with respect to the coating layer surface at an inspection position of the coating layer. An illuminating device that irradiates a plurality of pattern lights from an oblique direction toward the inspection position, and an image pickup device that images the coating layer at the inspection position from another oblique direction different from the diagonal direction with respect to the vertical line. A sheet-like image including an image processing device that extracts and processes a specular reflection component from image data at the inspection position irradiated with the plurality of pattern lights obtained by imaging with the image pickup device and determines whether the coating state is good or bad. Provided is a member manufacturing apparatus.

According to the method for manufacturing a sheet-shaped member of the present invention, the inspection accuracy of the coated state of the coated layer formed on the base sheet can be improved, and the sheet-shaped member can be stably manufactured.

It is a device block diagram which showed an example of the sheet-shaped member manufacturing apparatus preferable for carrying out the sheet-shaped member manufacturing method which concerns on this invention. As an example of the striped pattern illumination, it is an illumination pattern diagram which showed the example of 8 patterns of the striped pattern light which irradiates with one line. It is a schematic block diagram which showed the lighting apparatus and the image pickup apparatus at the inspection position on the roll surface. It is a top view which shows the example of the inspection image (the specular reflection component composite image) schematically. It is a top view which showed an example which applied the hot melt adhesive on the base material sheet. When the irradiation angle θ _L of the illumination light of the lighting device and the image pickup angle θ _C of the image pickup device are 15 ° (Fig. (A)), 30 ° (Fig. (B)), and 45 ° (Fig. (C)). A plan view schematically showing the inspection image (upper part of each figure), and shading shown by the frequency (vertical axis) of the base sheet and the hot melt adhesive (vertical axis) and the gray scale (horizontal axis) of 256 gradations. It is a figure (lower part of each figure). It is a flowchart which showed a preferable example of an inspection process. It is a top view which showed an example of the inspection area arranged in the inspection image of FIG. It is a drawing explaining the setting method of the threshold, (A) figure shows the characteristic value of a base sheet on the vertical axis, and the horizontal axis shows the basis weight of a hot melt adhesive, (B) figure shows. The vertical axis shows the area value of the white pixel, and the horizontal axis shows the basis weight of the hot melt adhesive. The figure (A) is a graph showing the area value of white pixels on the vertical axis and the trend of measured values showing the number of inspections on the horizontal axis, and the figure (B) is a graph showing the cause of contamination by paper dust. It is a plan view which shows the inspection image which included the defective part schematically, and the figure (C) is a plan view which showed the inspection image which included the defective part which is caused by air biting.

A preferred embodiment of the method for manufacturing a sheet-shaped member of the present invention will be described below with reference to the drawings.
In the method for manufacturing a sheet-shaped member of the present invention, a base sheet made of various materials can be used. For example, examples of the material of the base material sheet include a polymer sheet, a non-woven fabric, a mount (paper), a resin film, and the like. As the coating material used for forming the coating layer, various materials that can be applied to the base material sheet can be used. For example, examples of the coating material include functional agents such as adhesives (hot melt adhesives and various other adhesives), lotions and skin care agents. Further, the coating layer may be transparent, may be transparent, or may be chromatic (chromatic or achromatic), as long as the illumination light is specularly reflected.

The method for manufacturing a sheet-shaped member of the present invention has the following steps (I) to (VI) (hereinafter, simply referred to as steps (I) to (VI), respectively).
(I) A step of forming a coating layer on a base sheet being transferred in one direction.
(II) A step of irradiating a plurality of pattern lights from an oblique direction with respect to a perpendicular line to the surface of the coating layer at the inspection position of the coating layer toward the coating layer at the inspection position.
(III) A step of imaging the coating layer at the inspection position from another diagonal direction different from the diagonal direction with respect to the vertical line.
(IV) A step of extracting a specular reflection component from a plurality of images acquired in the image pickup step and synthesizing them to generate an inspection image.
(V) A step of setting at least one inspection area for the inspection image and calculating a measured value indicating a coating state of the coating layer.
(VI) A step of comparing the measured value with a preset threshold value to determine the quality of the coating state of the coating layer.
By going through the above steps, the specular reflection component of the reflected light in the coating layer can be suitably generated and captured, and the difference in shade between the coating layer and the base sheet in the acquired image data can be increased. Based on this, the inspection accuracy of the coating state in the entire region of the coating layer can be improved, and a stable sheet-like member can be manufactured.
Since the method for manufacturing a sheet-shaped member of the present invention utilizes the specular reflection component described above, it can be applied to various coating layers, and even if the coating layer is transparent, it is colored. The above effect can also be realized.

The method for manufacturing a sheet-shaped member of the present invention having such a step can be carried out by using, for example, the manufacturing apparatus 1 as shown in FIG.
First, the base material sheet 51 is continuously transferred in one direction from the raw fabric roll to the upstream of the manufacturing apparatus 1, and the coating material is applied to the base material sheet during the transfer to form the coating layer 52 (step). It is provided with a mechanism (not shown).
Then, as shown in FIG. 1, the manufacturing apparatus 1 inspects at the inspection positions of the transfer mechanism 10, the manufacturing line control unit 20, and the coating layer 52 that transfer the base sheet 51 on which the coating layer 52 is formed in one direction. It has an inspection system 30. These steps (II) to (VI) are performed.

Further, the manufacturing apparatus 1 has a cutting portion 41 for cutting the sheet-shaped member into a desired size after the inspection, and a discharging device 46 for the defective member. As a result, among the sheet-shaped members judged to be good or bad in the coating layer in the above step (VI), the sheet-shaped members judged to be defective are excluded from the production line, and the sheet-shaped members judged to be non-defective are taken as they are in the downstream process. Can be transferred to. The sheet-shaped member manufactured as a non-defective product in this way is incorporated together with other members to manufacture a predetermined product (sheet-shaped article). For example, the sheet-shaped member is incorporated into a predetermined product (sheet-shaped article) by laminating, joining, cutting, or the like with other members, if necessary.

As long as the transfer mechanism 10 transfers the base material sheet 51 to the inspection position 53, the configuration of the transfer mechanism 10 does not matter. For example, the transfer mechanism 10 includes two rolls 11 and 12 and a conveyor belt 13 wound around them and rotatably arranged. It is preferable that at least one of the rolls, for example, the roll 12, is provided with a motor 14 as a driving device for rotating the rolls. As shown in the figure, the drive method by the motor 14 is a direct drive in which the roll shaft is directly driven by the motor shaft even if it is a belt drive connecting the motor shaft (not shown) and the roll shaft (not shown). However, it may be another drive system.

The motor 14 is driven by a drive signal from the motor control unit 21. It is preferable that the motor amplifier 16 that amplifies the drive signal to an appropriate drive voltage is arranged between the motor control unit 21 and the motor 14. An encoder 15 is further connected to the motor 14.

The encoder 15 outputs the change in the mechanical position as an electric signal. For example, the pulse signal _SP is output in accordance with the rotation of the motor 14. Further, the encoder 15 measures the rotation position (for example, rotation angle) and rotation speed (for example, angular velocity) of the drive shaft (not shown) of the motor 14 with a sensor (not shown), and outputs the measurement result as an electric signal. It may be something to do. If the rotation position and rotation speed of the motor 14 can be measured, the position and transfer speed of the coating layer 52 coated on the base sheet 51 on the conveyor belt 13 of the transfer mechanism 10 that moves in conjunction with the motor 14 can be obtained. For example, a rotary encoder can be used as the encoder 15.

The motor amplifier 16 receives an operation signal from the motor control unit 21 of the production line control unit 20 described later, amplifies the voltage to an appropriate voltage for driving the motor 14, and sends the voltage to the motor 14. Further, the motor amplifier 16 transmits the electric signal (pulse signal) SP output by the _encoder 15 to the image processing device 31 included in the inspection system 30 described later.

The production line control unit 20 includes a motor control unit 21, a timing control unit 22, and an emission control unit 23.
As described above, the motor control unit 21 sends an operation signal of a target value such as the rotation speed and the rotation speed of the motor 14 to the motor amplifier 16.
The timing control unit 22 receives a signal generated for processing of each article from the position detector 45 described later, and transmits the signal to the image processing device 31 as a trigger signal _ST which is a signal for starting inspection. After receiving the trigger signal _ST , the image processing apparatus 31 receives the pulse signal _SP and performs imaging. That is, after the trigger signal _{ST transmitted} for each article is input, the image pickup is performed according to the pulse signal SP. The pulse signal _SP is transmitted from the encoder 15 each time the base sheet 51 advances a preset distance, and is transmitted a plurality of times for a length corresponding to one article. When a line scan camera is used as described later, imaging is performed by a preset number of lines, and a pulse signal Sp is set to match the number of lines.
The discharge control unit 23 determines that the coating layer 52 is defective based on the presence / absence (ON and OFF) of transmission of the determination signal _SJ by the image processing device 31, and the discharge signal _SE of the sheet-like member 54. Is transmitted to the discharge device 46. Further, the discharge control unit 23 is based on the presence / absence (ON and OFF) of transmission of the determination signal _SJ by the image processing device 31, based on the distance from the inspected place to the discharge device 46 and the transport speed of the production line. When it passes, it is judged whether to discharge it.

The inspection system 30 is positive from the lighting device 32 that illuminates the coating layer 52 at the inspection position 53, the image pickup device 33 that images the coated coating layer 52 at the illuminated inspection position 53, and the image data obtained by imaging with the image pickup device 33. It has an image processing device 31 that extracts and processes a reflection component and determines the quality of the coating layer 52.

<Lighting device>
The lighting device 32 carries out the step (II).
The lighting device 32 irradiates the illumination light from an oblique direction (a direction tilted by an angle θ _L with respect to the vertical line _LP ) with respect to the vertical line _LP with respect to the surface of the coating layer at the inspection position 53 of the coating layer 52 on the base sheet 51. Arranged to do. This angle θ _L is also referred to as an irradiation angle θ _L. The angle θ _L is appropriately set according to the material used, but is preferably in the following range. That is, the angle θ _L is set as an angle at which the illumination light can effectively generate a specular reflection component of the light reflected on the surface of the coating layer 51. The angle θ _L is set in the range of more than 0 degrees and less than 90 degrees with respect to the perpendicular line Lp. The angle θ _L effectively generates a specular reflection component, and from the viewpoint of clarifying the difference in shading on the image between the coating layer 52 and the base sheet 51 in the inspection image generated from the acquired image data described later. 15 degrees or higher is preferable, and 25 degrees or higher is more preferable. Further, the angle θ _L is 45 from the viewpoint of preventing the ratio of information in the height (thickness) direction of the coating layer 52 and the base sheet 51 from increasing too much in the inspection image generated from the acquired image data described later. The degree or less is preferable, and 35 degrees or less is more preferable.
Further, the position of the lighting device 32 is not particularly limited as long as it can accurately irradiate the coating layer 52 at the inspection position 53. From the viewpoint of suitably grasping the entire coating state of the coating layer 52 in the width direction (direction orthogonal to the transfer direction, hereinafter also referred to as X direction), along the same direction as the transfer direction (hereinafter, also referred to as Y direction). It is preferable to irradiate with.
The perpendicular line _LP at the inspection position 53 on the plane shown in FIG. 1 is a line perpendicular to the plane at the inspection position 53.

The lighting device 32 can sequentially irradiate illumination light composed of a plurality of pattern lights (lights having atypical patterns). For example, a striped pattern illuminating device capable of sequentially irradiating patterned light having a striped illuminance distribution while changing the phase of the illuminance distribution can be used. This striped pattern illuminating device can emit light while changing the phase in synchronization with imaging of 20,000 lines or more per second. Then, the pattern light of all the illuminance distributions can be irradiated to one line in the width direction (X direction) at the inspection position 53.
The coating layer 53 is irradiated with a plurality of pattern lights as described above to generate a specular reflection component, which is imaged by the image pickup apparatus 33 described later on the image of the coating layer 52 and the base sheet 51. The shade difference can be generated uniformly over the entire region.
As an example of the striped pattern illuminating device, for example, as shown in FIG. 2, an apparatus capable of irradiating eight patterns of striped pattern light with one line can be mentioned. Patterns 1 to 4 change the phase of the striped illuminance distribution in the width direction (X direction) of the base sheet 51. Patterns 5 to 8 change the phase of the striped illuminance distribution in the transfer direction (Y direction) of the base sheet 51. As an example of such a lighting device, there is a striped pattern lighting device CA-DZW30X manufactured by KEYENCE CORPORATION. In this striped pattern illuminating device, a plurality of line illuminations extending in the width direction (X direction) are arranged in the transfer direction (Y direction), and the illuminating is performed by the striped pattern light shown in FIG. Is.
The timing of light emission of the lighting device 32 is controlled by the timing control unit 22 included in the production line control unit 20. That is, the image processing device 31 controls the light emission triggered by the trigger signal _ST from the timing control unit 22. At the same time, the image processing apparatus 31 is controlled so that the timing of imaging is synchronized with the timing of the light _emission according to the pulse signal SP.

<Image pickup device>
The image pickup apparatus 33 carries out the step (III).
The image pickup apparatus 33 is the coating layer 52 from an oblique direction with respect to the perpendicular line LP with respect to the coating layer surface at the inspection position 53 of the coating layer 52 on the base sheet 51 (direction _tilted by an angle _{θ C} with respect to the vertical line LP). It is arranged to capture the reflected light. This diagonal direction (direction tilted by an angle θ _C with respect to the vertical line _{LP) is a different diagonal direction from the diagonal direction of the lighting device 32 (direction tilted by an angle θ L with} respect to the vertical line _LP ). This angle θ _C is also referred to as an imaging angle θ _C.
The angle θ _C in the image pickup apparatus 33 is set as an angle capable of preferably capturing the specular reflection component reflected on the surface of the coating layer 51 by the irradiation of the illumination device 32 and suppressing the capture of other reflection components. The angle θ _C is appropriately set according to the material used, but is preferably in the following range. That is, the angle θ _C is set in a range of more than 0 degrees and less than 90 degrees with respect to the perpendicular line Lp. The angle θ _C is 15 from the viewpoint of effectively capturing the specular reflection component and clarifying the difference in shading on the image between the coating layer 52 and the base sheet 51 in the inspection image generated from the acquired image data described later. More than 25 degrees is preferable, and more than 25 degrees is more preferable. Further, θ _C is 45 degrees from the viewpoint of preventing the ratio of information in the height (thickness) direction of the coating layer 52 and the base sheet 51 from increasing too much in the inspection image generated from the acquired image data described later. The following is preferable, and 35 degrees or less is more preferable.
As shown in FIG. 1, the image pickup apparatus 33 is arranged at a position opposite to the lighting apparatus 32 with the perpendicular line LP at the inspection position 53 interposed _therebetween , from the viewpoint of clearly imaging the coating layer 52 at the inspection position 53. Is preferable. Further, the image pickup apparatus 33 has a transfer direction (hereinafter, also referred to as Y direction) from the viewpoint of preferably grasping the coating state of the entire width direction (direction orthogonal to the transfer direction; hereinafter, also referred to as X direction) of the coating layer 52. It is preferable to take an image along the same direction as (.).

The image pickup apparatus 33 can sequentially image the reflected light composed of a plurality of pattern lights. For example, it consists of a line scan camera (line sensor). As an example of such a line scan camera, there is a line scan camera CA-HL02MX manufactured by KEYENCE CORPORATION.

It is preferable that the values of the angle (illumination angle) θ _L in the lighting device 32 and the angle (imaging angle) θ _C in the image pickup device 33 are equal to each other. Equal means that the angle difference Δθ (= | θ _L − θ _C |) is 5 degrees or less, preferably 1 degree or less, and more preferably 0 degrees. As a result, the image pickup angle θ _L of the image pickup device 33 can be matched with the specular reflection angle of the specular reflection component from the coating layer 52 at the irradiation angle θ _L of the lighting device 32, and the specular reflection component can be captured more preferably. be able to. Further, in the inspection image generated from the acquired image data described later, it is possible to clarify the difference in shading on the image between the coating layer 52 and the base sheet 51.

The inspection position 53 is preferably on the curved surface of the roll peripheral surface rather than on the flat surface of the conveyor belt 13. For example, as shown in FIG. 3, the inspection position 53 of the coating layer 52 of the base sheet 51 transferred on the peripheral surface of the roll 70 is arranged on a curved surface in the transfer direction. Since the base sheet 51 arranged on the curved surface is in a state of being tensioned, the base sheet is less likely to wrinkle. Further, since the illumination light is reflected only at the apex of the roll, stray light is unlikely to occur. Therefore, the specular reflection component of the coating layer 52 at the inspection position 53 can be more preferably captured by the image pickup apparatus 33. From this point of view, the inspection position 53 is preferably on the curved surface of the peripheral surface of the roll.
When the inspection position 53 is on a curved surface, as shown in FIG. 3, the perpendicular line LP at the inspection position 53 on the surface _70S (roll surface) of the roll 70 is the roll peripheral surface (roll rotation direction) at the inspection position 53. It becomes a line perpendicular to the _tangent line LT of the peripheral surface along the line.

<Image processing device>
The image processing apparatus 31 carries out the steps (IV) to (VI).
The image processing device 31 generates a plurality of images corresponding to the plurality of pattern lights acquired by the image pickup device 33 at the inspection position 53. The plurality of images are two-dimensional images generated by combining line images (one _- dimensional images) continuously generated according to the pulse signal SP. More specifically, a line image (one-dimensional image) is imaged as many as the number of pattern lights for one line, and a plurality of two-dimensional images in which the line images are combined are generated as many as the number of pattern lights. The specular reflection component is extracted from the plurality of images (two-dimensional images). Then, the specular reflection components extracted individually are combined to generate a specular reflection component composite image. This specular reflection component composite image becomes an inspection image. For example, an inspection image (specular reflection component composite image) as shown in FIG. 4 is generated.
In the inspection image shown in FIG. 4, as shown in FIG. 5, the hot melt adhesive is transferred onto the base sheet 51 in a strip shape along the transfer direction (Y direction) and intermittently in the width direction (X direction). It is an image obtained by taking an image from the coating layer 52 side of what was coated on the coating layer 52 to form the coating layer 52. However, the arrangement configuration of the coating layer 52 shown in FIG. 5 is only one example, and the present invention is not limited to this, and various arrangement configurations can be adopted. Further, FIGS. 4 to 6 and 8 to 10 show an example in which a polymer sheet is used as the base sheet 51 and a hot melt adhesive is used as the coating layer 52. However, this is only one example and can be used for various materials in the present invention.

Further, the image processing device 31 includes a measured value calculation means (not shown). This measured value calculating means sets at least one inspection area on the inspection image, performs binarization processing, and then calculates the measured value indicating the coating state of the coating layer. For example, the number of white pixels (area and width (length in the X direction)) corresponding to the coating layer 52 in the inspection area of the inspection image can be calculated as a measured value. At this time, the portion corresponding to the base sheet 51 has the number of black pixels.
Further, the image processing device 31 includes a quality (measured value) determination means (not shown). This quality determination means determines the quality of the coating state of the coating layer 52 by comparing the measured value with a preset threshold value.

In this way, the image processing device 31 can generate an inspection image by extracting a specular reflection component from the reflected light of the plurality of pattern lights captured by the image pickup device 33. Further, an inspection area is set for the inspection image, binarization processing is performed, and for example, the number of white pixels in the inspection area is measured to obtain a measured value indicating the coating layer 52. The quality of the inspection area can be determined by comparing this measured value with a preset threshold value. For example, the inspection image can be divided into a plurality of inspection regions, a threshold value can be set for each inspection region, and the quality of the inspection regions at a plurality of locations can be individually determined in one inspection image. The inspection area at this time can be arbitrarily set as appropriate, and can be set, for example, according to the arrangement of the coating layer 52.

In the method for manufacturing a sheet-shaped member of the present invention, as described above, the specular reflection component of the reflected light is suitably generated and captured for imaging. Therefore, in calculating the measured value, the base sheet 51 and the coating layer 52 are used. It is possible to increase the difference in shading on the image with. The larger the shade difference, the easier it is to perform the binarization process or the like more accurately, and the inspection based on the inspection image obtained thereby becomes highly accurate and stable.
From this point of view, the irradiation angle θ _L and the imaging angle θ _C are appropriately set according to the material used, and are more preferably within the above-mentioned ranges. For example, as shown in FIG. 6, when θ _C = θ _L = 30 ° (Fig. (B)) or θ _C = θ _L , compared to the case where θ _C = θ _L = 15 ° (Fig. (A)). In the case of = 45 ° (Fig. (C)), the difference between the gray scale value at which the number of pixels indicating the coating layer 52 peaks and the gray scale value at which the number of pixels indicating the base sheet 51 peaks. Is large, and the difference in shade is larger. In FIG. 6, PS means a polymer sheet as a base sheet 51, and HM indicates a layer of hot melt adhesive as a coating layer 52.

From the viewpoint of increasing the density difference, it is preferable to arrange a low-reflection material having a reflectance lower than that of the coating layer 52 portion on the side opposite to the coating surface (back surface side) of the base sheet 51 for imaging. As a result, the influence of the reflection of the background of the base sheet 51 can be suppressed to a small extent, and the information on the outermost surface can be suitably acquired. The light reflectance of the reflective material is preferably 30% or less, more preferably 10% or less, further preferably 5% or less, and particularly preferably 0%. This light reflectance refers to the light reflectance of a low-reflection material when exposed to light (for example, white light) composed of the wavelength band of the illumination light to be used. Specifically, examples of the low-reflection material include a matte material and a black material. Further, the black color may be blackish brown or dark gray.

Further, from the viewpoint of increasing the concentration difference, it is preferable that the surface of the coating layer 52 has less unevenness than the base sheet 51. As a result, the specular reflection component of the reflected light on the surface of the coating layer 52 becomes stronger than that of the surface of the base sheet, and the region of the coating layer 52 becomes whiter in the inspection image. On the other hand, the diffuse reflection component is dominant in the reflected light on the surface of the base sheet 51 as compared with the surface of the coating layer 52, and the region of the base sheet 51 becomes blacker in the inspection image. As a result, in the inspection image, the difference in shade between the base sheet 51 and the coating layer 52 on the image becomes larger.
For this reason, it is preferable that the coating layer 52 is smoothly formed on the surface of the base sheet 51 so as to fill the unevenness of the base sheet 51. Therefore, although it depends on the density of the base sheet 51, the higher the viscosity of the coating layer 52, the easier it is to stay on the surface of the base sheet 51, which is effective in increasing the shade difference of the inspection image. For example, in the case of a hot melt adhesive, it is preferable to have a viscosity of about 1000 to 50,000 MPa · s.

Further, the manufacturing apparatus 1 has a cutting portion 41 that cuts a continuum of sheet-shaped members having a coating layer 52 formed on a base sheet 51 into individual sheet-shaped members 54 after the above inspection is completed. Examples of the cutting portion 41 include a rotary cutter and the like. The rotary cutter is composed of opposite rolls 42 and 43, and the cutter 44 is arranged on one of the rolls 43. A position detector 45 is connected to the roll 43 having the cutter 44. The position detector 45 transmits a signal generated for machining of each article to the timing control unit 22.

Next, a preferable example of the method for manufacturing a sheet-shaped member of the present invention using the manufacturing apparatus 1 shown in FIG. 1 will be described more specifically.
First, in the above-mentioned step (I), as shown in FIG. 5, a hot melt adhesive is applied onto the base sheet 51 to form the coating layer 52.
Next, the above-mentioned steps (II) to (IV) are carried out according to the flowchart shown in FIG.

First, the "imaging process" is performed. In the "imaging step", the above-mentioned steps (II) and (III) are performed. Specifically, the pulse signal _{SP (FIG. 1) generated corresponding to the transfer distance of the base sheet 51 triggered by the trigger signal ST (} see FIG. 1) generated for the processing of each article. 1), a plurality of pattern lights are sequentially irradiated to the inspection position 53 to perform imaging. Here, eight pattern lights are irradiated to one line in the width direction (X direction) at the inspection position 53, and an image is taken by a line scan camera.
At this time, the irradiation angle θ _L and the imaging angle θ _C are angles that are oblique to the vertical line _LP with respect to the coating layer surface at the inspection position 53, respectively. The oblique direction of irradiation and the oblique direction of imaging are different directions from each other. It is preferable that the irradiation angle θ _L and the imaging angle θ _C are equal to each other, although the directions are different from each other. Further, it is preferable to set the irradiation angle θ _L and the imaging angle θ _C to the above-mentioned preferable ranges, respectively.

Next, an "image generation step" is performed. As a result, the above-mentioned step (IV) is performed. Specifically, in the "image generation step", the specular reflection component is extracted from a plurality of images obtained by imaging the coating layer 52 at the inspection position 53 irradiated with the plurality of pattern lights, and the specular reflection component is synthesized. Generate a composite image.

Next, a "measurement step" is performed. In the "measurement step", the above-mentioned step (V) is performed. Specifically, for the inspection image, for example, inspection regions A1 to A9 divided in the width direction (X direction) are set according to the coating pattern as shown in FIG. 8, and binarized for each inspection region. After the treatment, the measured value indicating the coating state of the coating layer is calculated. In the illustrated example, the measured value is calculated based on the area of each inspection area. In this case, the number of white pixels existing in each of the binarized inspection areas A1 to A9 is measured. That is, the total area of the white image is obtained from the number of white pixels. The total area of this white image is a measured value of the area of the coating layer 52 in each inspection area. When the width is used as the measured value instead of the area of the coating layer 52, for example, the coating width is measured by extracting the edge portion of the white image in the inspection area and calculating each edge width. Black pixels may be measured instead of white pixels.

Next, a "determination step" is performed. In the "determination step", the above-mentioned step (VI) is performed. Specifically, the quality of the coating state of the coating layer 52 is determined by comparing the above measured value with a preset threshold value. It is preferable to set the threshold value, which is the reference value for pass / fail judgment, for each inspection area in terms of improving the inspection accuracy.
This threshold value is appropriately set according to the relative relationship between each inspection area and the characteristic value of the coating layer 52. The characteristic value is a value that satisfies the functional condition required for the article to which the sheet-shaped member is applied. For example, when the coating layer 52 is a layer of a hot melt adhesive, it is a characteristic value that satisfies the functional condition of imparting sufficient adhesive strength to the base sheet.
Further, when the coating layer 52 is not an adhesive but a functional agent (for example, a skin care agent), the characteristic value can be a value that satisfies the functional condition required for the action exerted on the skin.
In this way, the threshold value for quality determination is set, and if the measured value (number of white pixels) exceeds the threshold value, it is determined to be a good product, and if it is equal to or less than the threshold value, it is determined to be defective.

For example, in the example of the inspection image shown in FIG. 8, the threshold value can be set as follows.
That is, as shown in FIG. 9A, when the basis weight of the coating layer of the hot melt adhesive applied to the base sheet 51 is more than 80 g / m ² , the characteristic value in the sheet-like member is satisfied. Therefore, as shown in FIG. 9B, the white pixel area value 4 × 10 ⁵ pixel corresponding to the boundary 80 g / m ² of the basis weight of the hot melt adhesive satisfying the above characteristic value is set as the threshold value. Can be done. As shown in the graph of FIG. 9B, if the white pixel area value exceeds the white pixel area value 4 × 10 ⁵ pixels set as the threshold value, the basis weight of the hot melt adhesive is sufficiently high and the coated state is in a coated state. It shows that it is good.
In this way, by setting a threshold value based on the characteristic value and determining whether the coating state is good or bad based on whether or not the threshold value is exceeded, whether or not a sheet-like member on which a good coating layer is actually formed is manufactured. Can be determined.

When a defect is determined, the sheet-shaped member 54NG determined to be defective is identified from the sheet-shaped members 54 individually cut after the inspection, and discharged from the production line as follows. Is preferable.
First, when it is determined that the product is non-defective, the image processing device 31 sets the determination signal _SJ to "ON". The determination signal _SJ is transmitted from the image processing device 31 of the inspection system 30 to the emission control unit 23 of the production line control unit 20. That is, a signal is transmitted to transmit "OK" information to the emission control unit 23. On the other hand, if it is determined to be defective, the image processing device 31 turns the determination signal _SJ to "OFF". That is, by not transmitting a signal, the information of "NG" is transmitted to the emission control unit 23.
When the discharge control unit 23 receives the determination signal SJ that has been turned “ON”, the discharge device 46 does not operate, and the sheet-shaped member _54OK determined to be a non-defective product is sent to the next step. When the determination signal _SJ is set to "OFF", the discharge control unit 23 transmits a discharge signal SE to the discharge device 46, and the discharge device 46 identifies and discharges the defective sheet-shaped member _54NG . Discharge is preferably performed by flowing the defective member through a line for collecting the defective member.

In this determination step, if the defect determination (determination signal is “OFF”) detected based on the measured value occurs frequently, an alarm notifying the coating abnormality can be output to, for example, the image display device 34. If it continues further, the manufacturing apparatus 1 can be stopped.

The event determined to be defective as described above is a white pixel, as seen in the portions indicated by reference numerals 91 and 92 in the graph of FIG. 10A in the steps of continuous transfer and continuous coating on the production line. Appears as a decrease in area value.
For example, depending on the type of base sheet, there are sheets that are prone to generate paper dust, and in such sheets, paper dust collects at the tip of the hot melt gun (not shown), and the hot melt adhesive is continuously missing. (See the region of reference numeral 91 in the inspection image of FIG. 10 (B)).
Further, air biting in the hose of the hot melt gun may cause the hot melt adhesive to come off in a large area (see the region of reference numeral 92 in the inspection image of FIG. 10C). The omission in this case occurs suddenly, unlike the clogging such as paper dust contamination.
When such an abnormality occurs, a defective product is detected by a good / bad judgment as described above. Defective products can be discharged based on this detection result. Further, when the defect determination occurs frequently, it is possible to output an alarm for notifying an abnormality such as a clogging alarm or an air biting alarm. If it continues, the manufacturing apparatus 1 can be stopped for confirmation.

According to the method for manufacturing a sheet-shaped member of the present invention, a specular reflection component of reflected light in the coating layer can be suitably generated and captured, and the difference in shading on the image between the coating layer and the base sheet in the acquired image data. Can be increased. Based on this, it is possible to improve the inspection accuracy of the coating state in the entire region of the coating layer, and it is possible to manufacture a stable sheet-shaped member. Further, since the above specular reflection component is used, it is possible to deal with various coating layers regardless of the presence or absence of a light emitting material that emits light by ultraviolet light, and the range (type) of the coating layer that can be inspected can be determined. Can be expanded.
Further, according to the apparatus for manufacturing a sheet-shaped member of the present invention, the above-mentioned method for manufacturing a sheet-shaped member of the present invention can be suitably carried out.

1 Manufacturing equipment 10 Transfer mechanism 20 Manufacturing line control unit 21 Motor control unit 22 Timing control unit 23 Emission control unit 30 Inspection system 31 Image processing device 32 Lighting device 33 Imaging device 34 Image display device 41 Cutting section 42, 43 Roll 44 Cutter 51 Base sheet 52 Coating layer 53 Inspection position 54 Sheet-like member 54OK Good sheet-like member 54NG Defective sheet-like member A1 to A9 Inspection area L _P Vertical line _LT Tangent line θ _L Irradiation angle θ _C Imaging angle

Claims (12)

It is a manufacturing method of sheet-shaped members.
The process of forming a coating layer on the base sheet being transferred in one direction,
A step of irradiating a plurality of pattern lights from an oblique direction with respect to a perpendicular line to the surface of the coating layer at the inspection position of the coating layer toward the coating layer at the inspection position.
A step of imaging the coating layer at the inspection position from another diagonal direction different from the diagonal direction with respect to the vertical line.
A step of extracting a specular reflection component from a plurality of images acquired in the step of imaging and synthesizing them to generate an inspection image, and a step of generating an inspection image.
A step of setting at least one inspection area for the inspection image and calculating a measured value indicating a coating state of the coating layer is included.
A method for manufacturing a sheet-shaped member. Angle θ with respect to the perpendicular in the diagonal direction to irradiate the pattern light _L And the angle θ with respect to the vertical line in the other diagonal direction in which the image is taken. _C Difference from Δθ ＝ ｜ θ _L -Θ _C The method for manufacturing a sheet-shaped member according to claim 1, wherein | is 0 ° or more and 5 ° or less. The method for manufacturing a sheet-like member according to claim 1 or 2 , wherein a low-reflection material having a reflectance lower than that of the coating layer portion is arranged on the side of the base material sheet opposite to the coating surface, and an image is taken. The method for manufacturing a sheet-shaped member according to any one of claims 1 to 3 , wherein any one or more of the area and the width of the coating layer in the inspection area of the inspection image is used for the calculation of the measured value. The method for manufacturing a sheet-shaped member according to any one of claims 1 to 4, which comprises a step of comparing the measured value with a preset threshold value to determine the quality of the coating state of the coating layer. The method for manufacturing a sheet-shaped member according to claim 5 , further comprising a step of discharging the sheet-shaped member whose coating state of the coating layer is determined to be defective by the step of determining the quality. The method for manufacturing a sheet-shaped member according to claim 5 or 6 , wherein an alarm for notifying a coating abnormality is output or the manufacturing apparatus is stopped when a defect is detected in the step of determining the quality. The method for manufacturing a sheet-shaped member according to any one of claims 1 to 7 , wherein the coating layer is an adhesive. A method for manufacturing a sheet-shaped article, wherein the sheet-shaped article is manufactured by incorporating the sheet-shaped member obtained by the method for manufacturing the sheet-shaped member according to any one of claims 1 to 8 . It is a manufacturing device for sheet-shaped members.
A coating device that forms a coating layer on a substrate sheet that is being transferred in one direction,
An illuminating device that irradiates a plurality of pattern lights from an oblique direction toward the inspection position with respect to a perpendicular line to the surface of the coating layer at the inspection position of the coating layer.
An image pickup device that images the coating layer at the inspection position from another diagonal direction different from the diagonal direction with respect to the vertical line.
The image processing apparatus includes an image processing apparatus that extracts and processes a specular reflection component from image data at the inspection position irradiated with the plurality of pattern lights obtained by imaging with the imaging apparatus and determines whether the coating state is good or bad.
Sheet-shaped member manufacturing equipment. The image processing device is
An inspection image generation means for generating an inspection image by extracting a specular reflection component from the image data composed of a plurality of line images acquired by the image pickup apparatus and synthesizing the specular reflection component.
A measurement value calculation means for setting at least one inspection area for the inspection image and calculating a measurement value indicating a coating state of the coating layer.
It includes a quality determination means for determining the quality of the coating state of the coating layer by comparing the measured value with a preset threshold value.
The apparatus for manufacturing a sheet-shaped member according to claim 10 . The manufacturing apparatus has a transfer mechanism for the base sheet, and a member of the transfer surface of the transfer mechanism, which is arranged on the side opposite to the coating surface of the base sheet, has a reflectance in the coating layer. The apparatus for manufacturing a sheet-like member according to claim 10 or 11, which is a lower reflective material.

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