JP2018036161A - Film inspection device, film inspection method, and film manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately inspect a defect of a film.SOLUTION: A film inspection device 1 includes: a light reception device 12 that by receiving light having been radiated to a film 2 and then having returned through the film 2, generates a signal for detecting a defect contained in the film 2; and a reflection roller 13 that in a visual field V of the light reception device 12, transports the film 2 while supporting the same from the opposite side to the light reception device 12.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a defect inspection of a film being conveyed.

  An optical technique is often used for defect inspection of a film being conveyed. In Patent Document 1, visible light and invisible light are irradiated from a light source to an inspection object such as a film, and the inspection object is inspected for defects by receiving these lights reflected by the inspection object. Defect inspection is disclosed. Patent Document 2 describes that a defect inspection is performed in which light applied to both surfaces of a film is captured by a camera and the image is processed. In film defect inspection using light reflection, the light source and the light receiving device are placed on the same side of the film, and the light that is irradiated from the light source to the film and reflected by defects such as foreign matter is collected on the light receiving device. doing.

Japanese Patent Publication “Japanese Unexamined Patent Application Publication No. 2014-20910 (published on February 3, 2014)” Japanese Patent Publication “JP 2008-116437 A (published on May 22, 2008)”

  The film being transported often shifts in a direction perpendicular to the film surface, so-called “fluttering”. This displacement can be suppressed to some extent by applying tension in the longitudinal direction of the film. However, the greater the tension, the greater the possibility that the film being transported will stretch or break, so it must be kept below a certain level. If the film flutters, the intensity of the reflected light collected on the light receiving device fluctuates regardless of the film defect, so that an accurate inspection result cannot be obtained. This tendency is particularly noticeable when the film is a porous secondary battery separator having a low mechanical strength. In the prior arts of Patent Documents 1 and 2, this problem is not considered. In view of the above problems, an object of the present invention is to accurately measure defects in a film being conveyed.

  In order to solve the above-described problems, the film inspection apparatus of the present invention receives a light irradiated on the film and returned through the film, thereby detecting a defect included in the film. And a first roller that conveys the film while supporting the film from the side opposite to the light receiving device within the field of view of the light receiving device.

  The film inspection method of the present invention includes a step of generating a signal for detecting a defect included in the film by receiving the light irradiated to the film and returning through the film with a light receiving device, And transporting the film while supporting the film from the side opposite to the light receiving device within the field of view of the light receiving device.

  The film manufacturing method of this invention includes each process which the above-mentioned film inspection method includes, and the process of removing the defect site | part of the said film examined based on the signal produced | generated in the said production | generation process.

  The present invention has an effect that a defect of a film can be inspected more accurately than before. Moreover, this invention has the effect that a film with few defects than before can be manufactured.

It is a side view and sectional view showing the composition of the film inspection device of Embodiment 1. It is a graph of the electric signal which the light-receiving device of the film test | inspection apparatus shown by FIG. 1 outputs. It is a side view explaining the arrangement | positioning and attitude | position which the light-receiving device and reflection roller of the film inspection apparatus shown by FIG. 1 can take. It is a side view which shows the structure of the film inspection apparatus of Embodiment 2. It is sectional drawing which shows the structure of the film inspection apparatus of Embodiment 3. It is a side view which shows the modification of the film test | inspection apparatus shown by FIG. It is sectional drawing which shows the other modification of the film inspection apparatus shown by FIG.

Embodiment 1
<< Configuration of Film Inspection Apparatus 1 >>
FIG. 1 is a diagram illustrating a configuration of a film inspection apparatus 1 according to the present embodiment, where (a) is a side view, and (b) is a light receiving device 12 and a reflection roller 13 (first roller) of (a). It is sectional drawing of the surface containing these. Note that the XYZ axes shown in FIG. 1 correspond to the XYZ axes shown in other drawings.

  The film inspection apparatus 1 is an apparatus for inspecting a defect of the film 2 being conveyed in the Y axis positive direction side. As shown in FIGS. 1A and 1B, the film inspection apparatus 1 includes light sources 11a and 11b, a light receiving device 12, a reflection roller 13, an inspection unit 14, and transport rollers 3a and 3b (second). Roller). In FIG. 1B, for the sake of brevity, the light sources 11a and 11b are indicated by broken lines, and the transport rollers 3a and 3b are omitted.

(Film 2)
The film 2 is a non-porous film before being processed into a secondary battery separator. The secondary battery separator is, for example, a porous film that allows lithium ions to move between the positive electrode and the negative electrode of a lithium ion secondary battery while separating them.

  Specifically, the film 2 is a polyethylene resin obtained by kneading ultra high molecular weight polyethylene and an inorganic filler (filler: for example, calcium carbonate, silica) or a plasticizer (for example, low molecular weight polyolefin, liquid paraffin). It is the film which shape | molded the composition. This polyethylene resin composition is obtained, for example, by kneading 100 parts by weight of ultrahigh molecular weight polyethylene, 100 to 400 parts by weight of an inorganic filler, and 5 to 200 parts by weight of a low molecular weight polyolefin having a weight average molecular weight of 10,000 or less.

In addition, the inspection object of the film inspection apparatus 1 is not limited to the above-mentioned film 2, and may be enumerated below. The inspection object is preferably one that transmits light to some extent. In this case, the effect of the reflection roller 13 described in the section “Effects of the color and surface roughness of the outer peripheral surface of the reflection roller 13” described later (in the electrical signal corresponding to the inspection light, Effect of increasing the contrast of the image and reducing the noise component). However, the inspection object may be a film that does not transmit light at all, such as a metal film having a certain thickness. Also in this case, the effect that the film 2 is prevented from being changed in position and posture with respect to the light receiving device 12 in the inspection region.
A film obtained by removing the inorganic filler or plasticizer from the film obtained by molding the above polyethylene resin composition. A stretched film obtained by uniaxially or biaxially stretching this film. A film obtained by applying a solution containing aramid to the stretched film, and A film in which a solution containing alumina / carboxymethylcellulose is applied to a laminated film or stretched film in which an aramid heat-resistant layer is formed on one or both sides by removing the solvent from the solution, and an alumina heat-resistant layer on one side by removing the solvent from the solution Alternatively, a film in which a solution containing polyvinylidene fluoride is applied to a laminated film / stretched film formed on both sides, and a laminated film / optical film / cloth, paper in which an adhesive layer is formed on one or both sides by removing the solvent from the solution , Pulp, cellulose Films and laminated films are used as secondary battery separators. In recent years, with the increase in capacity of secondary batteries, secondary battery separators are required to have a thinner film. Specifically, a separator for a secondary battery having a film thickness of 5 to 10 μm is required. Since such a film is particularly low in strength, there is a particular risk of fluttering, stretching or breaking during transportation. In other words, in the inspection of such a secondary battery separator, the present invention has particularly excellent effects described later.

(Defects in film 2)
The defect of the film 2 inspected by the film inspection apparatus 1 is, for example, the following foreign substances mixed in the film 2.
・ Metals (iron, stainless steel, aluminum, copper, zinc, brass, etc.)
・ Gel (ultra high molecular weight polyethylene, etc.)
・ Filler (calcium carbonate, etc.) agglomerates, oil droplets, roller abrasives, metal oxides (aluminum oxide, chromium oxide, etc.)
・ Anti-seizure agent (metal salt)
As described above, the foreign matter of the film 2 to be inspected by the film inspection apparatus 1 is different from the film 2 in optical characteristics. Note that holes, wrinkles, unevenness, etc. of the film 2 are also included in the defects of the film 2 that the film inspection apparatus 1 inspects.

(Conveyance rollers 3a and 3b)
The transport rollers 3a and 3b are rollers that transport the film 2 to the Y-axis direction side by contacting and rotating the film 2. As shown in FIG. 1A, the transport rollers 3a and 3b have a cylindrical shape and are rotatably supported. When the external transport apparatus is transporting the film 2, the film inspection apparatus 1 may not include the transport rollers 3a and 3b. In addition, the conveyance roller 3a may be an unwinding roller for unwinding the film 2 wound around a cylindrical core fitted to itself. Moreover, the conveyance roller 3b may be a winding roller for winding the film 2 around a cylindrical core fitted to itself.

(Light sources 11a and 11b)
The light sources 11a and 11b irradiate the film 2 with light. The light emitted from the light source 11a is visible light. The light irradiated by the light source 11b is ultraviolet light or infrared light.

  As shown in (b) of FIG. 1, the light sources 11 a and 11 b irradiate light over the entire X-axis direction of the film 2. Note that the X-axis direction is a direction perpendicular to the longitudinal direction and the thickness direction of the film 2. In addition, the light sources 11 a and 11 b irradiate the same portion of the film 2 with light. In order to irradiate light as described above, the light sources 11a and 11b are diffused with, for example, a plurality of light emitting diodes (LEDs) arranged in the X-axis direction, other light emitting elements, or LEDs or other light emitting elements. A combination of a plate or a wavelength filter is provided.

  In addition, when the light irradiated to the film 2 from the outside of the film inspection apparatus 1 can be used as the light for irradiating the film 2, the film inspection apparatus 1 does not need to include the light sources 11a and 11b.

(Light receiving device 12)
The light receiving device 12 detects a defect included in the film 2 by receiving light irradiated to the film 2 by the light sources 11a and 11b and returning to the Z axis positive direction side through the film 2. A device for generating a signal.

  The light returned from the film 2 includes light reflected on the surface or inside of the film 2, light scattered on the surface or inside of the film 2, and reflected or scattered by the reflection roller 13 through the film 2 and again. Light transmitted through the film 2 is included. Hereinafter, these lights are referred to as “inspection light”.

  The light receiving device 12 includes a lens for condensing the inspection light, and condenses the inspection light from almost the entire X-axis direction of the film 2 as shown in FIG. The depth of field of this lens is set so as to roughly include the front and back surfaces of the film 2 on the reflection roller 13.

  The light receiving device 12 further includes two charge coupled devices (CCD) and two optical filters corresponding thereto. Each of the two CCDs converts the collected inspection light into an electrical signal. Two optical filters are provided for each of the two CCDs. One CCD can convert a light component from the light source 11a into an electric signal, and the other CCD can convert a light component from the light source 11b into an electric signal. Thus, each transmits only specific light. Thereby, the light receiving device 12 can divide the collected inspection light into a light component from the light source 11a and a light component from the light source 11b, and convert each component into an electric signal.

(Reflection roller 13)
As shown in FIGS. 1A and 1B, the reflection roller 13 is disposed at a position facing the light receiving device 12 through the film 2 and is in contact with one surface of the film 2 on the Z-axis negative direction side. The film 2 is supported and rotated in the direction in which the film 2 is conveyed.

  Therefore, the inspection light received by the light receiving device 12 is a portion of the film 2 that is supported from one surface by the reflecting roller 13, that is, the inspection light that passes through a portion in which the change in position and orientation relative to the light receiving device 12 is suppressed. Become.

  In addition, the conveyance rollers 3a and 3b for conveying the film 2 are respectively disposed on the same side as the reflection roller 13 with respect to the film 2 and immediately before and after the reflection roller 13 along the conveyance path of the film 2. .

  The reflection roller 13 reflects or scatters the light transmitted through the film 2 among the light irradiated on the film 2 by the light sources 11a and 11b. The outer peripheral surface in contact with the film 2 in the reflection roller 13 is made of white to ivory vinyl chloride that has not been matted.

  “Non-matte treatment” in the present application means that the glossiness (surface state) of the outer peripheral surface in contact with the film 2 in the reflection roller 13 is measured using, for example, GORI's GlossChecker IG-331 manufactured by HORIBA. In the case of 60-degree specular gloss, which is the type of specular gloss measurement method in -Z8741, this means that the gloss is 10 or more and less than 76 when the gloss is 100 when the reflectance is 10%.

  On the other hand, “matte processing” means that the glossiness is 0 or more and less than 10. When the glossiness is 76 or more, the outer peripheral surface is defined as a mirror surface. For example, the glossiness of the outer peripheral surface made of vinyl chloride is 60 or more and 70 or less.

  In addition, the color of the outer peripheral surface of the reflection roller 13 in this embodiment does not need to be what is called achromatic white, and should just be a color which reflects or scatters light sufficiently. Specifically, when expressed in the Munsell color system, the hue is not particularly defined, but the lightness is preferably 7.0 or more and 9.5 or less, and the saturation is preferably 0.5 or more and 3 or less. For example, in the first embodiment, the hue of the outer peripheral surface is 5Y, the lightness is 9, and the saturation is 0.5. In Embodiment 2 described later, the hue of the outer peripheral surface is 2.5Y, the lightness is 7.5, and the saturation is 2.

(Inspection unit 14)
As shown in FIGS. 1A and 1B, the inspection unit 14 is connected to the light receiving device 12 and receives an electronic signal converted by the light receiving device 12. This electric signal reflects the intensity of the inspection light received by the light receiving device 12 from almost the entire X-axis direction of the film 2. The inspection unit 14 inspects the film 2 for defects from this electrical signal. Note that the film inspection apparatus 1 may be connected to an external inspection unit having the same function as the inspection unit 14. At this time, the film inspection apparatus 1 may not include the inspection unit 14.

  The inspection unit 14 may be realized by a logic circuit (hardware) formed in an integrated circuit (IC chip) or the like, or may be realized by software using a CPU (Central Processing Unit).

  In the latter case, the inspection unit 14 includes a CPU that executes instructions of a program that is software that realizes the function, and a ROM (Read Only Memory) in which the above-described program and various data are recorded so as to be readable by the computer (or CPU). Alternatively, a storage device (these are referred to as “recording media”), a RAM (Random Access Memory) that expands the above-described program, and the like are provided. And the objective of this invention is achieved when a computer (or CPU) reads and runs the above-mentioned program from the above-mentioned recording medium. As the above-described recording medium, a “non-temporary tangible medium” such as a tape, a disk, a card, a semiconductor memory, a programmable logic circuit, or the like can be used. Further, the above-described program may be supplied to the above-described computer via an arbitrary transmission medium (such as a communication network or a broadcast wave) that can transmit the program. The present invention can also be realized in the form of a data signal embedded in a carrier wave in which the above-described program is embodied by electronic transmission.

<< Operation of Film Inspection Apparatus 1 >>
(Inspection for defects)
The intensity of the electrical signal that the inspection unit 14 receives from the light receiving device 12 corresponds to the intensity of the inspection light from the film 2. When the film 2 has a defect, the intensity of the inspection light changes. Therefore, the inspection unit 14 holds, as a reference value, an electrical signal corresponding to the intensity of inspection light from the film 2 having no defect acquired in advance, and the reference value and from the film 2 to be inspected for the presence or absence of a defect. By comparing with the electric signal to be inspected corresponding to the intensity of the inspection light, it is possible to inspect the film 2 for defects. For example, the inspection unit 14 can inspect for the presence or absence of a defect when a value obtained by dividing the electric signal to be inspected by a reference value becomes smaller than a certain value.

  Note that the inspection unit 14 may receive a plurality of electrical signals from the light receiving device 12 a plurality of times, and the average of these electrical signals may be the above-described reference value or the electrical signal to be inspected. Here, the electrical signal fluctuates reflecting the surface state of the film 2 even when the film 2 has no defect. The inspection unit 14 can obtain an electrical signal in which this variation is suppressed by averaging a plurality of electrical signals.

(Inspection of defect location)
FIG. 2 is a graph of an electrical signal output from the light receiving device 12 of the film inspection apparatus 1 shown in FIG. 1, and (a) to (d) use a reflection roller 13 having a different surface color or processing method. It is a graph of time. The horizontal axis “inspection width” of these graphs corresponds to the position of the film 2 in the X-axis direction. The vertical axis “signal intensity” of the graph corresponds to the intensity of the inspection light reflected at the position of the film 2 in the X-axis direction corresponding to the horizontal axis and received by the light receiving device 12. The value of the origin on the vertical axis is the lower limit value of the electrical signal that can be output by the light receiving device 12.

  As shown in FIG. 2A, the intensity of the inspection light from the central portion of the film 2 in the X-axis direction is smaller than the intensity of the inspection light from the end portion of the film 2 in the X-axis direction. Therefore, the inspection unit 14 receives the electrical signal shown in the graph of FIG. 2A, and “the defect that reduces the amount of inspection light exists in the central portion of the film 2 in the X-axis direction” and the position of the defect. Can be inspected.

(Inspection of defect dimensions)
As the defect of the film 2 increases in the X-axis direction, the range in which the electric signal intensity shown in the graph of FIG. Therefore, the inspection unit 14 can inspect the dimension of the defect in the X-axis direction based on the waveform of the electric signal shown in the graph of FIG. Specifically, the inspection unit 14 obtains an inspection width range in which the intensity of the electric signal becomes smaller than a certain value, and multiplies the magnification of the lens of the light receiving device 12 to convert it into the length of the film 2 in the X-axis direction. By doing, the dimension of the X-axis direction of the film 2 can be test | inspected.

  Further, as the defect of the film 2 increases in the Y-axis direction, the period during which the electric signal intensity shown in the graph of FIG. Therefore, the inspection unit 14 can inspect the dimension of the defect in the Y-axis direction based on the waveform of the electrical signal shown in the graph of FIG. Specifically, the inspection unit 14 obtains a period in which the intensity of the electric signal is smaller than a certain value, and multiplies the film 2 by the conveyance speed to convert the film 2 into the length in the Y-axis direction. 2 in the Y-axis direction can be inspected.

  As described above, the inspection unit 14 can inspect the dimensions of the film 2 in the X and Y axis directions.

(Defect type inspection)
If the types of defects of the film 2 are different, the intensity of inspection light corresponding to visible light from the light source 11a (hereinafter referred to as “first intensity”) and the intensity of inspection light corresponding to infrared light or ultraviolet light from the light source 11b. (Hereinafter referred to as “second intensity”), a difference occurs in the degree of intensity change due to the presence or absence of defects. When the defect of the film 2 is, for example, a metal, the first strength and the second strength change to the same extent. On the other hand, when the defect is, for example, oil, the rate of change is greater for the second strength than for the first strength. Therefore, the light receiving device 12 simultaneously measures the first intensity of visible light emitted from the light source 11a and the second intensity of infrared light or ultraviolet light emitted from the light source 11b, and the inspection unit 14 compares them. The type of defect in the film 2 can be specified.

  When the defect type inspection is not performed, the film inspection apparatus 1 may include one light source instead of two light sources.

<< Effect of film inspection apparatus 1 >>
As shown in FIGS. 1A and 1B, when the film inspection apparatus 1 includes the reflection roller 13, the film 2 has a position and posture with respect to the light receiving device 12 in the inspection area of the film inspection apparatus 1. Change is suppressed. Therefore, in the film inspection apparatus 1, the light receiving device 12 can output an electric signal reflecting the defect of the film 2 more accurately as compared with a conventional film inspection apparatus that does not include the reflection roller 13.

  Therefore, the film inspection apparatus 1 has an effect of being able to inspect defects of the film 2 more accurately than before. This effect is not achieved only when the light receiving device 12 and the reflection roller 13 are arranged as shown in FIG.

(Relationship between field of view of light receiving device 12 and arrangement of reflecting roller 13)
FIG. 3 is a side view for explaining the arrangement and posture that the light receiving device 12 and the reflection roller 13 of the film inspection apparatus 1 shown in FIG. In FIG. 3, the light sources 11a and 11b, the inspection unit 14, and the transport rollers 3a and 3b are omitted for the sake of brevity.

  As indicated by a broken line in FIG. 3, the light receiving device 12 collects the inspection light from the field of view V that is a range in which the lens of the light receiving device 12 can collect the inspection light on the CCD. The film 2 in the visual field V is conveyed while being supported from the side opposite to the light receiving device 12 by the reflection roller 13 at the center in the Y-axis direction.

  However, the relationship between the visual field V of the light receiving device 12 and the arrangement of the reflection rollers 13 is not limited to the above, and the film 2 is supported while being supported from the opposite side of the light receiving device 12 within the visual field of the light receiving device 12. It only has to be done.

  For example, the light receiving device 12 may be moved to the position 12a. In this case, the visual field V changes to the visual field Va, but the film 2 in the visual field Va is conveyed while being supported from the side opposite to the light receiving device 12 by the reflection roller 13 at the end in the Y-axis direction. In addition, although the position 12a in FIG. 3 has moved to the Y-axis negative direction side with respect to the light receiving device 12, it may be moved to the Y-axis positive direction side.

  Further, the light receiving device 12 may be moved to the position 12b and the posture may be inclined. Also in this case, the visual field V changes to the visual field Va, but as described above, the film 2 in the visual field Va is transported while being supported from the opposite side to the light receiving device 12 by the reflection roller 13 at the end in the Y-axis direction. Has been. In addition, although the position 12b in FIG. 3 has moved to the Y axis positive direction side with respect to the light receiving device 12, it may be moved to the Y axis negative direction side.

  In these cases, the inspection light received by the light receiving device 12 is transmitted through the portion P of the film 2 supported by the reflecting roller 13, that is, the portion P in which the change in position and posture relative to the light receiving device 12 is suppressed. The returned inspection light will be included. As a result, compared to a configuration that does not include the reflection roller 13, in the inspection light received by the light receiving device 12, light intensity fluctuations that are unrelated to defects in the film 2 are less likely to occur. Therefore, in the film inspection apparatus 1, the light receiving device 12 can output a signal reflecting the defect of the film 2 more accurately as compared with a conventional film inspection apparatus that does not include the reflection roller 13.

  Therefore, the film inspection apparatus 1 has an effect of being able to inspect defects of the film 2 more accurately than before.

(Relationship between optical axis of light receiving device 12 and arrangement of reflection roller 13)
The light receiving device 12 condenses the inspection light about the optical axis OA that is a straight line connecting the center of the lens of the light receiving device 12 and the focal point, as indicated by a one-dot chain line in FIG. The optical axis OA passes through the portion P of the film 2 supported by the reflection roller 13.

  Further, the optical axis OA is in a positional relationship perpendicularly intersecting the rotation axis of the reflection roller 13, but the light receiving device 12 is moved to the position 12c and the posture is inclined, so that the optical axis OA changes to the optical axis OAa. Also good. In addition, although the position 12c in FIG. 3 moves to the Y-axis positive direction side with respect to the light receiving device 12 and the posture is inclined in the right-rotating direction around the X-axis, the position 12c is on the Y-axis negative direction side. The posture may be tilted in the direction of left rotation about the X axis as the center axis.

  In these cases, in the inspection light received by the light receiving device 12, the ratio of the inspection light that has returned through the portion P of the film 2 in which the change in position and orientation relative to the light receiving device 12 is suppressed increases. Therefore, fluctuations in light intensity unrelated to defects in the film 2 are less likely to occur.

  The optical axis OA passes through the contact position between the film 2 and the reflection roller 13 and is perpendicular to the rotation axis of the reflection roller 13, that is, the reflection roller 13 passes through the film 2 with respect to the light receiving device 12. In the inspection light received by the light receiving device 12, the ratio of the inspection light returned through the portion P of the film 2 is further increased. Therefore, the fluctuation of the light intensity that is unrelated to the defect of the film 2 is further less likely to occur.

(Influence of the color and surface roughness of the outer peripheral surface of the reflection roller 13)
The effect that the change in the position and posture of the film 2 with respect to the light receiving device 12 in the inspection region is suppressed is that the inspection light includes light that is transmitted through the film 2 and reflected or scattered by the reflection roller 13 and transmitted through the film 2 again. Even if not, it is played.

  On the other hand, when the inspection light includes light that is transmitted through the film 2 and reflected or scattered by the reflection roller 13 and then transmitted through the film 2 again, characteristics of the outer peripheral surface (color, By adjusting the surface roughness, etc., as shown in the graph of FIG. 2A, in the electrical signal corresponding to the inspection light, the contrast between the normal portion and the defective portion of the film 2 is increased, or noise is increased. Components can be reduced. Below, the influence of the characteristic of the outer peripheral surface which touches the film 2 of the reflection roller 13 is demonstrated.

  As described above, the electrical signal shown in the graph of FIG. 2A is obtained when the outer peripheral surface in contact with the film 2 is white and the reflective roller 13 that is not matted (small surface roughness) is used. , An electric signal output from the light receiving device 12. The foreign matter on the film 2 is often a dark color. According to the said structure, since the contrast with such a foreign material and the film 2 increases on the reflective roller 13, the film inspection apparatus can test | inspect the defect of a film more correctly.

  The electric signal shown in the graph of FIG. 2B is an electric signal output from the light receiving device 12 when the reflection roller 13 that has a white outer peripheral surface in contact with the film 2 and has been matted is used. . As shown in the graph of FIG. 2B, the waveform of the electrical signal is the same as the waveform of the electrical signal shown in the graph of FIG. At the end of, there is a relatively large fluctuation due to noise components. At this time, the inspection unit 14 may not detect a significant difference even if the above-described reference value is compared with the electrical signal to be inspected. Therefore, in the inspection of the defect of the film 2, it is desirable that the outer peripheral surface in contact with the film 2 of the reflection roller 13 is not subjected to the matt treatment.

  The electric signal shown in the graph of FIG. 2C is an electric signal output from the light receiving device 12 when the outer peripheral surface in contact with the film 2 is gray and the reflection roller 13 that is not matted is used. . As shown in the graph of (c) of FIG. 2, the waveform of this electric signal has a “signal intensity” reaching a lower limit value at the center of the inspection width. The “signal strength” is generally lower than the “signal strength” of the electric signal shown in the graph of FIG. At this time, the inspection unit 14 may not detect a significant difference even if the above-described reference value is compared with the electrical signal to be inspected. Therefore, in the inspection of the defect of the film 2, the outer peripheral surface in contact with the film 2 of the reflection roller 13 tends to be desirably white.

  The electric signal shown in the graph of FIG. 2D is an electric signal output from the light receiving device 12 when the reflection roller 13 that is matt and has a gray outer peripheral surface in contact with the film 2 is used. . As shown in the graph of FIG. 2D, the waveform of the electrical signal is the same as the waveform of the electrical signal shown in the graph of FIG. There is a relatively large fluctuation at the end of the. At this time, the inspection unit 14 may not detect a significant difference even if the above-described reference value is compared with the electrical signal to be inspected. Therefore, in the inspection of the defect of the film 2, the outer peripheral surface in contact with the film 2 of the reflection roller 13 has a tendency that it is desirable that the outer peripheral surface is not matted and is white.

(Film inspection method)
A film inspection method executed by the film inspection apparatus 1 is also included in the present invention. The film inspection method includes a step of generating a signal for detecting a defect included in the film 2 by receiving the inspection light irradiated to the film 2 and returned through the film 2 by the light receiving device 12. And the step of transporting the film 2 while supporting the film 2 from the side opposite to the light receiving device 12 in the field of view V or Va of the light receiving device 12.

  As shown in FIGS. 1 (a) and 1 (b), the generating step means that the light received by the light source 11a / 11b on the film 2 is received by the light receiving device 12, and is shown in the graph of FIG. 2 (a). Generating an electrical signal. The step of transporting is a step of transporting the film 2 to the Y axis positive direction side along the trajectory defined by the transport rollers 3a and 3b, as shown in FIG.

  By the above film inspection method, the defect of the film 2 can be inspected more accurately than before.

(Film production method)
A film manufacturing method using the above-described film inspection method is also included in the present invention. This film manufacturing method includes a step of removing defective portions of the film based on the light reception result of the light receiving step in addition to the generating step and the conveying step included in the above-described film inspection method.

  The removing step is a step performed on the Y axis positive direction side of the film inspection apparatus 1 shown in FIGS. In this removing step, the defective part of the film 2 inspected based on the light reception result of the light receiving step is cut and removed. The cut film is connected to, for example, another film.

  By the above film manufacturing method, the film 2 with fewer defects than before can be manufactured.

[Embodiment 2]
In the present embodiment, members having the same functions as those described in the above-described embodiments are denoted by the same reference numerals and description thereof is omitted. The same applies to other embodiments described later.

<< Configuration of Film Inspection Apparatus 1A >>
FIG. 4 is a side view showing the configuration of the film inspection apparatus 1A of the present embodiment. As shown in FIG. 4, the film inspection apparatus 1 </ b> A includes the same members as the members included in the film inspection apparatus 1. However, in the film inspection apparatus 1 </ b> A, unlike the film inspection apparatus 1, the transport rollers 3 a and 3 b are in contact with the Z axis positive direction side of the film 2. In addition, the Z-axis positive direction side is the side opposite to the reflection roller 13 with respect to the film 2.

<< Operation and Effect of Film Inspection Apparatus 1A >>
The film inspection apparatus 1A operates in the same manner as the film inspection apparatus 1, and can inspect defects of the film 2 more accurately than before. Further, in the film inspection apparatus 1A, since the transport rollers 3a and 3b act so as to press the film 2 against the reflection roller 13, changes in the position and posture of the film 2 with respect to the light receiving device 12 are further suppressed. Therefore, 1 A of film inspection apparatuses can test | inspect the defect of the film 2 more correctly.

  However, in the film inspection apparatus 1, the transport rollers 3 a and 3 b and the reflection roller 13 are arranged on the same side with respect to the film 2. For this reason, in the film inspection apparatus 1, the space in which the light sources 11a and 11b and the light receiving device 12 are provided can be secured wider than the film inspection apparatus 1A. Therefore, in the film inspection apparatus 1, the freedom degree when providing the light sources 11a * 11b and the light-receiving device 12 increases.

  In addition, the above-mentioned film inspection method implemented using 1 A of film inspection apparatuses and the above-mentioned film manufacturing method using this film inspection method are also contained in this invention.

[Embodiment 3]
<< Configuration of Film Inspection Apparatus 1B >>
FIG. 5 is a cross-sectional view showing the configuration of the film inspection apparatus 1B of the present embodiment. FIG. 5 corresponds to (b) of FIG. As FIG. 5 shows, the film inspection apparatus 1B is provided with the same member as the member with which the film inspection apparatus 1 is provided except the concave reflective roller 13A (1st roller).

  Unlike the reflective roller 13, the concave reflective roller 13 </ b> A has a diameter at the center in the direction of the rotation axis that is gradually smaller than the diameter at both ends. The roller having such a shape is sometimes referred to as a “reverse crown roller”. Thus, the concave reflection roller 13A has a shape that extends the film 2 in the rotation axis direction of the concave reflection roller 13A.

  The depth of the central part of the concave reflection roller 13A is a value obtained by dividing the difference between the diameters of both ends and the central part by two. The optimum depth in the defect inspection of the film 2 depends on the length of the concave reflecting roller 13A in the rotation axis direction. For example, if the length in the rotation axis direction is 1000 mm, the depth is desirably 1 mm or less. In addition, the outer peripheral surface facing the film 2 of the concave reflection roller 13 </ b> A is made of white vinyl chloride that has not been matted, like the reflection roller 13.

<< Operation and Effect of Film Inspection Apparatus 1B >>
The film 2 is conveyed while being in contact with the outer peripheral surfaces on both ends in the rotation axis direction of the concave reflection roller 13A. Thereby, the film 2 conveyed in the outer peripheral surface of a both end part side is extended outside, and the wrinkle etc. which arose in the film 2 during conveyance can be extended. As a result, generation of wrinkles and the like in the film 2 can be suppressed, and the surface state can be made more uniform. Therefore, in the film inspection apparatus 1B, the fluctuation of the surface state at the defect inspection position of the film 2 can be suppressed, and the defect of the film 2 can be inspected more accurately.

  In addition, even if the reflection roller of the film inspection apparatus 1B is a convex reflection roller, generation | occurrence | production of a wrinkle etc. in the film 2 can be suppressed and a surface state can be brought closer to constant. The convex reflection roller is a reflection roller in which the diameter of the central portion in the rotation axis direction is gradually larger than the diameter of both end portions. The above-described film inspection method implemented using the film inspection apparatus 1B and the above-described film manufacturing method using this film inspection method are also included in the present invention.

(Replacement of the transport roller 3a with a concave roller)
A film inspection apparatus in which the transport roller 3a of the film inspection apparatus 1 shown in FIG. 1A is replaced with a concave roller, a convex roller (crown roller), or an expander roller is also included in the present invention. That is, the transport roller 3a is disposed at a position immediately before the reflection roller 13 along the transport path of the film 2, and may have a shape or a mechanism for extending the film 2 in the direction of the rotation axis of the transport roller 3a. . In this film inspection apparatus, before the film 2 is transported to the reflection roller 13, wrinkles and the like of the film 2 are reliably stretched by the transport roller 3a. Therefore, in this film inspection apparatus, the fluctuation of the surface state at the defect inspection position of the film 2 can be reliably suppressed, and the defect of the film 2 can be inspected more accurately.

  In addition, a film inspection device in which the transport roller 3a of the film inspection device 1B is replaced with a concave roller, a convex roller, or an expander roller is also included in the present invention. In this film inspection apparatus, the variation of the surface state at the defect inspection position of the film 2 can be more reliably suppressed, and the defect of the film 2 can be inspected more accurately.

  However, when the wrinkle-stretching function of the film 2 works sufficiently in the transport roller 3a, it is better to use the normal (outer peripheral surface cylindrical surface) reflecting roller 13 instead of the concave reflecting roller 13A having the wrinkle-stretching function. Sometimes it is good. This is because when the concave reflection roller 13A is used, the wrinkle stretching function causes the wrinkles of the film 2 to be stretched in the inspection region, and accordingly, the defects are slightly displaced in the inspection region. As a result, the inspection unit 14 In some cases, an error is included in the position and size of the defect measured in step (b). On the other hand, when the normal reflection roller 13 is used, the above error hardly occurs.

[Modification 1]
FIG. 6 is a side view showing a modification of the film inspection apparatus 1 shown in FIG. 1, wherein (a) is a film inspection apparatus 1 </ b> C in which the transport roller 3 b is arranged on the Z-axis positive direction side with respect to the film 2. (B) shows film inspection apparatus 1D by which the conveyance roller 3a was arrange | positioned with respect to the film 2 at the Z-axis positive direction side. As shown in FIGS. 6A and 6B, one of the transport rollers 3 a and 3 b is arranged on the reflection roller 13 side with respect to the film 2, and the other side is opposite to the reflection roller 13 with respect to the film 2. The film inspection apparatuses 1C and 1D arranged in the above are also included in the present invention. The film inspection devices 1C and 1D have the effect of achieving both the effect exhibited by the film inspection device 1 and the effect exhibited by the film inspection device 1A.

[Modification 2]
(Film inspection device with multiple light receiving devices)
FIG. 7 is a cross-sectional view showing another modification of the film inspection apparatus 1 shown in FIG. 1, wherein (a) shows a configuration in which a plurality of light receiving devices 12 are arranged in the X-axis direction, and (b) shows FIG. 5C shows a configuration in which a pair of light receiving devices 12A and 12B having different wavelengths of inspection light to be detected are arranged in the X-axis direction, and FIG. 8C shows a plurality of light receiving devices 12A and 12B shown in FIG. The arrangement is shown in FIG. 7 corresponds to (b) of FIG. In FIG. 7, the light sources 11a and 11b, the inspection unit 14, and the transport rollers 3a and 3b are omitted for the sake of brevity.

  As shown in FIG. 7A, the film inspection apparatus 1E includes a plurality of light receiving devices 12. The film inspection apparatus 1E has the same configuration as the film inspection apparatus 1 except that the number of light receiving devices 12 is different. Each light receiving device 12 collects the inspection light from a part of the film 2 in the X-axis direction. The plurality of light receiving devices 12 are arranged in the X-axis direction, thereby collecting the inspection light from almost the entire X-axis direction of the film 2 as a whole. The inspection unit 14 is connected to each light receiving device 12 (not shown).

  With the above configuration, the range of the film 2 on which the individual light receiving devices 12 collect the inspection light can be fitted, for example, the diameter of the lens of the light receiving device 12 can be reduced. Thereby, distortion of the field of view of the lens and chromatic aberration are suppressed. Therefore, the film inspection apparatus 1E can inspect defects of the film 2 more clearly than the film inspection apparatuses 1.1A to 1D including only one light receiving device 12.

  As shown in FIG. 7B, the film inspection apparatus 1F includes a pair of light receiving devices 12A and 12B. The film inspection device 1F has the same configuration as the film inspection device 1 except for the light receiving device 12. The light receiving devices 12 </ b> A and 12 </ b> B include a lens that condenses the inspection light, and condenses the inspection light from almost the entire X-axis direction of the film 2.

  The light receiving device 12 includes two sets of CCDs and two sets of optical filters corresponding thereto, but each of the light receiving devices 12A and 12B includes one pair of a CCD and an optical filter. ing. Then, the optical filter of the light receiving device 12A transmits only the inspection light from the light source 11a. For this reason, the light receiving device 12A can detect only the inspection light from the light source 11a. The optical filter of the light receiving device 12B transmits only the inspection light from the light source 11b. For this reason, the light receiving device 12B can detect only the inspection light from the light source 11b. As described above, the wavelengths of the inspection light received by the light receiving devices 12A and 12B are different from each other. The inspection unit 14 is connected to the light receiving devices 12A and 12B (not shown).

  As shown in FIG. 7C, the film inspection apparatus 1G includes a plurality of sets of light receiving devices 12A and 12B shown in FIG. The film inspection apparatus 1G has the same configuration as the film inspection apparatus 1 except for the light receiving device 12. Each set of the light receiving devices 12 </ b> A and 12 </ b> B collects inspection light from a part of the film 2 in the X-axis direction. The plurality of sets are arranged in the X-axis direction, thereby collecting the inspection light from almost the entire X-axis direction of the film 2 as a whole. The inspection unit 14 is connected to each of the light receiving devices 12A and 12B (not shown).

  With the above configuration, the film inspection apparatus 1G can inspect defects of the film 2 more clearly and more accurately than the above-described film inspection apparatuses 1 and 1A to 1D including only one light receiving device 12.

(Other light receiving devices)
The light receiving device 12 may be configured to include a light receiver including a lens and a spectroscope that separates the inspection light collected by the light receiver. In this configuration, the spectroscope splits the inspection light into a spectrum, divides it into light components from the light source 11a and light components from the light source 11b, and converts each component into an electrical signal.

  The light receiving device 12 may be a contact sensor (CIS) module. The CIS module includes a plurality of imaging elements (for example, CCDs) arranged in one direction, an optical filter, and a lens array. The optical filter is provided for each image sensor, and transmits only specific light so that the specific image sensor can convert only specific light into an electric signal. The lens array is obtained by arranging small lenses in one direction described above. With the above configuration, the CIS module can divide the collected inspection light into the light component from the light source 11a and the light component from the light source 11b, and convert each component into an electrical signal.

[Summary]
The film inspection apparatus according to the present invention includes a light receiving device that generates a signal for detecting a defect included in the film by receiving light irradiated to the film and returned through the film, and the light receiving device. A first roller for conveying the film while supporting the film from the side opposite to the light receiving device within the field of view of the device.

  According to the above configuration, the light receiving device receives the light irradiated to the film and returned through the film. This film is conveyed while being supported by the first roller from the side opposite to the light receiving device within the field of view of the light receiving device.

  Therefore, the light received by the light receiving device includes light returned through a portion of the film that is supported by the first roller, that is, a portion in which a change in position and posture with respect to the light receiving device is suppressed. become. As a result, according to the said structure, compared with the structure which is not equipped with a 1st roller, the fluctuation | variation of the light intensity unrelated to a film defect does not occur easily in the light which a light-receiving device receives. Therefore, in this film inspection apparatus, compared with the conventional film inspection apparatus which does not have a 1st roller, the light-receiving device can output the signal which reflected the defect of the film more correctly.

  Therefore, the film inspection apparatus can inspect defects of the film more accurately than before.

  The “light returned through the film” includes the light returned by being reflected on the surface or inside of the film, the light returned by being scattered on the surface or inside of the film, and the film. For example, light that has been transmitted and reflected or scattered by the first roller and then transmitted again through the film is applicable.

  Moreover, in the film inspection apparatus of this invention, it is desirable for the said 1st roller to support the part through which the optical axis of the said light-receiving device passes in the said film.

  According to the above configuration, in the light received by the light receiving device, the ratio of the light that has returned through the portion of the film in which the change in position and posture with respect to the light receiving device is suppressed increases. For this reason, fluctuations in light intensity that are unrelated to the film defects are less likely to occur. Moreover, it becomes possible to test | inspect, conveying a film at high speed because the said fluctuation | variation becomes difficult to occur.

  In the film inspection apparatus of the present invention, it is desirable that the first roller is disposed at a position facing the light receiving device via the film.

  According to the said structure, in the light which a light-receiving device receives, the ratio of the light which returned through the part by which the change of the position with respect to a light-receiving device and the attitude | position with respect to the light-receiving device was suppressed becomes still larger. Therefore, the fluctuation of the light intensity that is unrelated to the film defect is further less likely to occur.

  In the film inspection apparatus of the present invention, it is preferable that the light received by the light receiving device includes light transmitted through the film, reflected or scattered by the first roller, and transmitted again through the film.

  According to the said structure, a said 1st roller can be functioned as a reflection roller. Therefore, by adjusting the characteristics (color, surface roughness, etc.) of the outer peripheral surface of the first roller in contact with the film, the contrast between the normal part and the defective part of the film can be increased in the light received by the light receiving device. The noise component contained in the light can be reduced. As a result, the film inspection apparatus can inspect defects of the film more accurately.

  Moreover, in the film inspection apparatus of this invention, the brightness in the Munsell color system of the outer peripheral surface which contact | connects the said film of the said 1st roller is 7 or more and 9.5 or less, and the saturation in the Munsell color system of the said outer peripheral surface Is preferably 0.5 or more and 3 or less.

  In the film inspection apparatus of the present invention, the glossiness of the outer peripheral surface in contact with the film of the first roller is 60% specular gloss, which is a type of specular gloss measurement method in Japanese Industrial Standard JIS-Z8741, and the reflectivity. When the glossiness when 100% is 10% is 100, it is preferably 10 or more.

  Film foreign matter is often dark in color. According to the said structure, since the contrast mentioned above can be raised, the said film inspection apparatus can test | inspect the defect of a film more correctly.

  Moreover, the film inspection apparatus of this invention has the 2nd roller arrange | positioned in the position immediately before or immediately after the said 1st roller along the conveyance path | route of the said film, and the said 1st roller with respect to the said film. It is desirable to further provide.

  According to the above configuration, the first roller and the second roller are arranged on the same side with respect to the film. For this reason, a wide space for providing the light receiving device can be secured. Therefore, in the said film inspection apparatus, the freedom degree when providing a light-receiving device increases.

  Moreover, the film inspection apparatus of this invention is the 2nd roller arrange | positioned in the position just before or immediately after the said 1st roller along the conveyance path | route of the said film, and the said 1st roller with respect to the said film. It is desirable to provide further.

  According to the said structure, since a 2nd roller acts so that a film may be pressed on a 1st roller, the change of the position and attitude | position with respect to the light-receiving device of a film is suppressed more. Therefore, the film inspection apparatus can inspect defects of the film more accurately.

  Moreover, in the film inspection apparatus of this invention, the said 2nd roller is arrange | positioned in the position immediately before the said 1st roller along the conveyance path | route of the said film, The said film is made into the rotating shaft direction of the said 2nd roller. It is desirable to have an extending shape or mechanism.

  According to the said structure, before a film is conveyed to a 1st roller, a wrinkle etc. of a film are reliably extended by a 2nd roller. Therefore, in this film inspection apparatus, the fluctuation of the surface state at the defect inspection position of the film can be surely suppressed, and the defect of the film can be inspected more accurately.

  In the film inspection apparatus of the present invention, it is desirable that the first roller has a shape that extends the film in the rotation axis direction of the first roller.

  According to the said structure, the 1st roller can extend the wrinkles etc. which arose in the film during conveyance. As a result, the generation of wrinkles and the like in the film can be suppressed, and the surface state can be made more uniform. Therefore, in the said film inspection apparatus, the fluctuation | variation of the surface state in the defect inspection position of a film is suppressed, and the defect of a film can be test | inspected more correctly.

  The film inspection method of the present invention includes a step of generating a signal for detecting a defect included in the film by receiving the light irradiated to the film and returning through the film with a light receiving device, And transporting the film while supporting the film from the side opposite to the light receiving device within the field of view of the light receiving device.

  According to the above method, the defect of the film can be inspected more accurately than before.

  The film manufacturing method of this invention includes each process which the above-mentioned film inspection method includes, and the process of removing the defect site | part of the said film examined based on the signal produced | generated in the said production | generation process.

  According to the said manufacturing method, a film with few defects than before can be manufactured.

[Additional Notes]
The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

1.1A-1G Film inspection device 2 Film 3a / 3b Conveyance roller (second roller)
11a, 11b Light source 12, 12A, 12B Light receiving device 13 Reflection roller (first roller)
13A concave reflective roller (first roller)
14 Inspection Department

Claims (12)

A light receiving device that generates a signal for detecting a defect included in the film by receiving light irradiated to the film and returned through the film;
A first roller for conveying the film while supporting the film from the side opposite to the light receiving device in the field of view of the light receiving device;
A film inspection apparatus comprising:   The film inspection apparatus according to claim 1, wherein the first roller supports a portion of the film through which an optical axis of the light receiving device passes.   The film inspection apparatus according to claim 1, wherein the first roller is disposed at a position facing the light receiving device via the film.   4. The light received by the light receiving device includes light that is transmitted through the film, reflected or scattered by the first roller, and transmitted again through the film. 5. The film inspection apparatus according to item. The brightness in the Munsell color system of the outer peripheral surface in contact with the film of the first roller is 7 or more and 9.5 or less,
5. The film inspection apparatus according to claim 1, wherein a saturation of the outer peripheral surface in the Munsell color system is 0.5 or more and 3 or less.   The glossiness of the outer peripheral surface in contact with the film of the first roller is the glossiness when the reflectivity is 10% in the 60 ° specular gloss which is a kind of the specular gloss measurement method in Japanese Industrial Standard JIS-Z8741. The film inspection apparatus according to claim 1, wherein the film inspection apparatus is 10 or more when 100 is set.   2. The apparatus according to claim 1, further comprising a second roller disposed immediately before or immediately after the first roller along the film conveyance path and on the same side as the first roller with respect to the film. To 6. The film inspection apparatus according to any one of claims 1 to 6.   The apparatus further comprises a second roller disposed immediately before or immediately after the first roller along the film conveyance path and on the opposite side of the film from the first roller. The film inspection apparatus according to any one of 1 to 6. The second roller is
It is arranged at a position just before the first roller along the film transport path,
Having a shape or mechanism for extending the film in the direction of the rotation axis of the second roller,
The film inspection apparatus according to claim 7 or 8, wherein   The said 1st roller has a shape which extends the said film to the rotating shaft direction of the said 1st roller, The film inspection apparatus as described in any one of Claim 1 to 9 characterized by the above-mentioned. Receiving a light irradiated to the film and returned through the film by a light receiving device to generate a signal for detecting a defect included in the film;
Transporting the film while supporting the film from the opposite side of the light receiving device within the field of view of the light receiving device;
A film inspection method comprising: Each process included in the film inspection method according to claim 11;
Removing the defective portion of the film inspected based on the signal generated in the generating step;
The film manufacturing method characterized by including.

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