JP5001815B2 - Film inspection equipment - Google Patents

Description

  The present invention relates to a film inspection apparatus for performing an in-line inspection in a line for producing a film having a fine line on the surface.

  There is a mesh film in which a mesh is formed with fine metal wires on a transparent film such as PET. The mesh film transmits light because the fine metal wire has a line width of several tens of μm and an interval of several hundreds of μm. Moreover, electromagnetic waves can be shielded by the mesh. Therefore, it is attached to the surface of various electronic devices such as a plasma display, a computer, and a mobile phone.

  Examples of methods for forming fine metal wires include photo-etching a metal foil bonded to a transparent film to form fine metal wires, and then forming an adhesive film thereon by thermocompression bonding, or metal particles and a binder resin. There is a method in which a conductive paste containing a solvent and a solvent is printed on the surface of a film and dried. It is necessary to inspect whether or not the mesh is formed in a desired shape. As described above, the mesh is of the micron order, and it is necessary to inspect the mesh with a microscope or the like. Since the inspection is based on an enlarged image, the depth of field of a microscope or the like is reduced. Since the mesh film on the in-line vibrates in the direction of the depth of field, the enlarged image is out of focus and becomes out of focus, and it is difficult to inspect with the enlarged image. At present, it is difficult to inspect the mesh film in-line.

  Therefore, the currently employed inspection is an in-line final process, which is an off-line inspection using a microscope placed on a desk after extracting a sample of the mesh film. This method is a destructive inspection for extracting a sample, which is not preferable in manufacturing. If it is a visual inspection, there are individual differences and an extra work process is required. Also, if the mesh film is produced in a roll rather than a single sheet, the first and last portions of the roll can be extracted, but the middle of the roll cannot be extracted. If an abnormality occurs during the manufacturing process, defective products may continue to be manufactured until the end of the roll.

  Patent Document 1 discloses a method for accurately inspecting the line width of a mesh film by image processing. However, this is not an in-line inspection for producing a mesh film, but an off-line inspection on a desk. Therefore, there are problems as described above.

JP 2004-333355 A

  An object of the present invention is to provide a film inspection apparatus capable of performing in-line whether or not fine lines formed on a film are formed in a predetermined shape.

  The film inspection apparatus of the present invention is in close contact with the transparent film side of the film, rotates in synchronization with the moving speed of the film, and has a surface subjected to light non-reflective treatment, and a thin wire of the film in close contact with the roller A means to magnify and shoot a part of the film, a light source that irradiates the film with light that erases the shadow of the fine line when the filming means shoots the film, and an image captured by the means to shoot And a means for performing arithmetic processing on the thin film and detecting an abnormality of the thin line formed on the film.

  The film is transferred while being in close contact with the roller. At this time, the fine line is on the top, and the photograph is taken by means of photographing while enlarging a part of the film while focusing on the fine line. At the time of shooting, light is irradiated on the film from above and from the thin line, so that it is possible to shoot without making a shadow on the thin line against the background of the dark color of the roller by the light non-reflection process. The brightness difference between the roller and the thin line is increased, and the arithmetic processing can be easily performed.

  The light non-reflection treatment applied to the roller is preferably a black matte treatment. Also, a micrometer for adjusting the focus is attached to the photographing means. Further, the fine line is a thin metal line, and in order to determine abnormality, means for extracting the fine metal line forming the mesh from the film image photographed by the photographing means and obtaining the width and interval of the extracted fine metal line; The computer functions as means for storing predetermined values of the width and interval of the fine metal wires and determining that an abnormality occurs if the width and interval of the extracted fine metal wires do not fall within the predetermined values.

  According to the present invention, since the film is in close contact with the roller, it is possible to shoot an image in which a fine line is in focus even in the case of enlarged shooting with a very shallow depth of field. By applying a light non-reflective treatment to the roller that forms the back of the thin line, it is possible to make the thin line that reflects the light without creating a shadow stand out, and it is easy to determine the abnormality of the thin line.

  An inspection apparatus for a film on which a thin line of the present invention is formed will be described with reference to the drawings. As the film to be inspected, a mesh film in which a mesh is formed with fine metal wires on the transparent film described in the prior art is used. As an example of the mesh film, the line width of the fine metal wire is about 5 to 30 μm, and the interval is about 100 to 500 μm. As shown in FIG. 3 (a), the mesh film 12 has a mesh formed with fine metal wires 18 in rectangular regions 16 provided at regular intervals in a band-shaped transparent film 14. After the mesh is formed on the transparent film 14, the inspection is performed in the middle of winding the mesh film 12 in a roll shape.

  The inspection apparatus 10 of the present invention shown in FIG. 1 and FIG. 2 focuses the mesh on the inspection roller 20 on which the mesh film 12 closely contacts and rotates in synchronization with the moving speed of the mesh film 12. A camera 22 that shoots while enlarging a part of the mesh film 12, a light source 24 that irradiates the mesh film 12 with light from the periphery of the camera 22, and a computer 40 that performs arithmetic processing on the captured image to determine an abnormality in the mesh. With. In FIG. 1 and FIG. 2, the fine metal wires 18 are omitted.

  The surface of the inspection roller 20 is subjected to non-reflecting treatment for light. An example of the light non-reflective process is a black matte process. This is because the mesh formed by the fine metal wires 18 reflects light and the transparent film 14 transmits light, so that it is possible to capture an image that highlights the mesh against a dark background. Unnecessary reflected light from the inspection roller 20 can be eliminated by the non-reflective processing of light, and noise during photographing can be reduced.

  The diameter of the inspection roller 20 is about 150 to 300 mm. If the diameter is reduced, it will not be possible to shoot in a plane. Since the magnified shooting is performed, the depth of field becomes shallow, and if the shooting range is a curved surface, the entire mesh cannot be focused. Therefore, the diameter of the inspection roller 20 needs to be a certain size.

  A guide roller 26 is provided to bring the mesh film 12 into close contact with the inspection roller 20. The guide roller 26, the inspection roller 20, and the guide roller 26 are arranged in this order to run the mesh film 12 as shown in FIG. At the position of the inspection roller 20, the transparent film 14 is in close contact with the inspection roller 20, and the thin metal wire 18 is not in close contact with the inspection roller 20. The rollers 20 and 26 rotate in synchronization with the moving speed of the mesh film 12. By bringing the mesh film 12 into close contact with the inspection roller 20, fluttering of the mesh film 12 is suppressed.

  The camera 22 includes a lens 28 for enlarging a part of the mesh film 12, a two-dimensional sensor 30 that receives light, and a microscope tube 32 that couples the lens 28 and the two-dimensional sensor 30. As the lens 28, an objective lens used for a microscope, a microscope, or the like is used. The magnification is about 3 to 30 times. The two-dimensional sensor 30 is a CCD or CMOS two-dimensional image sensor. The two-dimensional sensor 30 shoots at a speed (light reception time) at which the moving mesh film 12 is stopped so as not to shake the photographed mesh film 12. The light quantity value received by the two-dimensional sensor 30 is converted into image data and sent to the computer 40. A microscope cylinder 32 used in a microscope, a microscope, or the like is used between the lens 28 and the two-dimensional sensor 30, and an image enlarged by the lens 28 is sent to the two-dimensional sensor 30.

  A micrometer 34 is attached to the camera 22 so that the camera 22 can be moved in the direction of depth of field. In FIG. 2, it is the vertical direction. The micrometer 34 is used to adjust the focus to the mesh. As shown in FIG.3 (b), the mesh (metal fine wire 18) is formed on the transparent film 14, and it focuses on the vertex of a mesh. The micrometer 34 may be configured to focus by autofocus.

  A linear motor 36 is attached to the micrometer 34 so that the camera 22 can move in the width direction of the mesh film 12. The camera 22 is attached to a linear motor 36 via a micrometer 34. The linear motor 36 is supported by a linear motor guide 38. The movement of the linear motor 36 may be controlled by the computer 40. Further, in order to obtain the position of the mesh abnormality, the position of the camera 22 in the width direction of the mesh film 12 may be obtained by a linear scale, and the data of the position may be sent to the computer 40.

  A plurality of light sources 24 are provided around the camera 22 so that the shadow of the fine metal wires 18 of the mesh film 12 does not appear in the photographed image. The plurality of light sources 24 are arranged around the microscope tube 32 and are square or circular. The light source 24 emits light in synchronization with the timing at which the two-dimensional sensor 30 receives light. Since light is irradiated from above the mesh film 12 and in each direction of the mesh film 12, the image is taken by the camera 22 without shadows on the fine metal wires 18. In addition, since the inspection apparatus 10 is used in a room such as a factory, the light source 24 secures an amount of light sufficient for the two-dimensional sensor 30 to image the mesh film 12.

  The camera 22 takes images at regular intervals. One point or a plurality of points may be photographed for each region 16 of the mesh film 12 in FIG. 3A, or one region 16 may be selected from the plurality of regions 16 and one point may be photographed. good.

  The image data of the mesh film 12 photographed by the camera 22 is sent to the computer 40. In order to determine the abnormality by the arithmetic processing, the fine metal wires 18 forming the mesh are extracted, the means for obtaining the width and interval of the extracted fine metal wires 18, and the predetermined values of the width and interval of the fine metal wires 18 are stored. If the width and interval of the extracted thin metal wires 18 do not fall within the predetermined values, the computer 40 is operated as means for determining that there is an abnormality.

  As described above, the image data 44 includes the thin metal wire 18 that reflects white against the background of the dark color of the inspection roller 20 (FIG. 4). As described above, the thin metal wire 18 is copied so that there is no shadow. Therefore, the extraction of the thin metal wire 18 may be performed by extracting the data of the white portion from the image data 44. There is little preprocessing for extracting the data of the white portion, and the image data 44 is digital data, which is very easy. Further, the outer edges of the thin metal wires 18 are determined from the average of the widths of the extracted white portions, and the distance between the outer edges arranged in parallel may be used as the width or interval of the thin metal wires 18 to remove noise during photographing. it can. Furthermore, a process of removing noise may be performed before extracting the white part.

  If an abnormality is detected, a signal may be sent to the warning lamp to turn on the warning lamp or stop the mesh film 12 manufacturing apparatus. The computer 40 may display image data in which an abnormality is detected on the monitor 42. Furthermore, an abnormal position may be specified from the production speed of the mesh film 12, the imaging cycle of the sensor 30, the position of the linear scale, and the like, and the position may be displayed on the monitor 42.

  If the image is out of focus when image processing is performed, intermediate colors of white and black increase. When extracting white color from the image data 44, a means for determining that the camera 22 is out of focus may be included if a certain amount or more of intermediate colors are detected. This can be dealt with when the focus of the camera 22 is deviated due to some factor when winding the mesh film 12, and can be adjusted again so as to return to normal inspection.

  With the above-described configuration, the mesh film 12 can be photographed and inspected at regular intervals. The inspection can be performed even while the mesh film 12 is being wound up in a roll shape, and the apparatus for manufacturing the mesh film 12 can be stopped if an abnormality that the mesh is cut in the middle of the roll is detected.

  The mesh film 12 to be inspected has a mesh in the region 16 at regular intervals in the transparent film 14, but the apparatus of the present invention can be applied even if the mesh is continuously provided on the transparent film 14. .

  The metal film 18 is not limited to the mesh film 12 as long as the fine metal wires 18 are formed on the transparent film 14. The fine metal wire 18 is not limited to a mesh shape, and various shapes may be formed by the fine metal wire 18. Although the computer 40 inspects the line width and the interval, only one of them may be used depending on the contents of the inspection. Further, the metal thin wire 18 can be changed to various thin wires. In this case, it is necessary that the difference in brightness between the inspection roller 20 and the thin line when photographing is increased.

  When the inspection roller 20 vibrates, the inspection roller 20 and the camera 22 may be indirectly connected by an arbitrary member so that the camera 22 vibrates in the same manner. The focus shift due to the vibration of the inspection roller 20 can be corrected.

  In addition, the present invention can be carried out in a mode in which various improvements, modifications, and changes are added based on the knowledge of those skilled in the art without departing from the gist thereof.

It is a perspective view which shows the structure of the test | inspection apparatus of this invention. It is the figure which expanded the inspection roll vicinity of the inspection apparatus of this invention. It is a figure which shows a mesh film, (a) is a front view of a strip | belt-shaped mesh film, (b) is a partial cross section figure of a mesh film. It is a figure which shows an example of the image | photographed image data.

Explanation of symbols

10: Film inspection device 12: Mesh film 14: Transparent film 16: Area 18: Metal thin wire 20: Inspection roller 22: Camera 24: Light source 26: Guide roller 28: Lens 30: Two-dimensional sensor 32: Microscope tube 34: Micro Meter 36: Linear motor 38: Linear motor guide 40: Computer 42: Monitor 44: Image

Claims (4)

A film inspection device in which a thin line is formed on one side of a transparent film,
A roller that is in close contact with the transparent film side of the film and rotates in synchronization with the moving speed of the film, and the surface is subjected to a light non-reflective treatment;
A means for focusing on the fine line of the film in close contact with the roller and enlarging a part of the film for photographing;
A light source for irradiating the film with light that erases the shadow of the fine line when the means for photographing shoots the film;
Means for performing an arithmetic process on the image taken by the photographing means and detecting an abnormality of a thin line formed on the film;
Inspection device with The inspection apparatus according to claim 1, wherein the light non-reflective process is a black matte process. The inspection apparatus according to claim 1, wherein a micrometer for adjusting a focus is attached to the photographing unit. The fine wire is a metal fine wire, and a mesh is formed by the metal fine wire,
The means for detecting the abnormality comprises
Means for extracting the fine metal wires forming the mesh from the image taken by the photographing means and obtaining the width and interval of the extracted fine metal wires;
Means for storing a predetermined value of the width and interval of the thin metal wire, and determining that the width and the interval of the extracted thin metal wire are abnormal if they do not fall within the predetermined value;
4. The inspection apparatus according to claim 1, further comprising:

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