JP2012202714A - Tool for appearance inspection of transparent sheet material and appearance inspection method for transparent sheet material using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tool for appearance inspection of a transparent sheet material and an appearance inspection method for transparent sheet material using the same that irradiate the sheet material with light for appearance inspection of the transparent sheet material and put a camera in focus on a surface of the sheet material with good reproducibility whichever of optical images by its transmitted light and reflected light is used.SOLUTION: There is provided the tool for inspection used to put the camera in focus on the surface of the transparent sheet material in a method of inspecting appearance of the transparent sheet material by irradiating the transparent sheet material with light and picking up an optical image of the transparent sheet material by the transmitted light and/or reflected light by the camera. The tool for inspection includes a rectangular frame member, which can be mounted at an appearance inspection position of the transparent sheet material in replacement with the transparent sheet material and at least one light-color thread member and/or at least one dark-color thread member extended on the frame member in level with the surface of the transparent sheet material when the frame member is mounted at the appearance inspection position.

Description

  The present invention relates to an inspection jig used for visual inspection of a transparent sheet material used for an optical filter or the like, in particular, an inspection jig used for focusing a camera on the surface of a sheet material, and the same. The present invention relates to an appearance inspection method.

  When manufacturing a transparent sheet material such as a transparent resin film used for an optical filter for a display panel or the like, defects such as foreign matter, streaks, unevenness, and coloring due to the quality of the raw material or the manufacturing process may occur. Since these appearance defects can cause the performance of the final product to deteriorate, appearance inspection is performed in the sheet material manufacturing process and fed back to the manufacturing process, or appearance inspection is performed in the product inspection process to eliminate defective products. It is necessary to do. In general, when visual inspection of a transparent sheet material is performed, light is irradiated to the transparent sheet material to be inspected, an optical image of the sheet material by transmitted light or reflected light is captured with a camera, etc., and the presence or absence of a defect in the inspection sheet material is checked. An analysis method is often used (for example, Patent Document 1).

JP 2008-233301 A

  However, in the case of a transparent sheet material, since the object is transparent, even if the sheet material is irradiated with light and an optical image based on the transmitted light is used, an optical image based on reflected light is used. It is difficult to focus the camera or the like on the surface of the sheet material. Therefore, the adjustment of the focus of the camera or the like may vary depending on the operator or the inspection apparatus, and it is difficult to ensure the reproducibility of the inspection under the same conditions.

  Therefore, the purpose of the present invention is to irradiate the sheet material with light when performing an appearance inspection of the transparent sheet material, and use either an optical image by the transmitted light or an optical image by the reflected light. An object of the present invention is to provide a transparent sheet material appearance inspection jig capable of focusing a camera on the surface of a sheet material with good reproducibility.

  Another object of the present invention is to provide a method for inspecting the appearance of a transparent sheet material using the inspection jig.

  The object is to focus the camera in a method for inspecting the appearance of a transparent sheet material by irradiating the transparent sheet material with light and taking an optical image of the transparent sheet material with transmitted light and / or reflected light with a camera. An inspection jig used to match the surface of a transparent sheet material, a rectangular frame member that can be placed in place of the transparent sheet material at a position for visual inspection of the transparent sheet material, and the appearance of the frame member At least one light-colored thread member and / or at least one dark-colored thread stretched on the frame member so as to have the same height as the surface of the transparent sheet material when placed at the inspection position This is achieved by an inspection jig having a member. It is difficult to focus the camera on the transparent sheet material because the object is transparent. In the inspection jig of the present invention, since the light-colored thread-like member and / or dark-colored thread-like member stretched so as to have the same height as the surface of the transparent sheet material is included, in the case of transmitted light, the dark color By focusing the camera on the thread-like member and focusing the camera on the bright-colored thread-like member in the case of reflected light, it is possible to accurately focus on the position of the surface of the transparent sheet material.

Preferred embodiments of the inspection jig of the present invention are as follows.
(1) An auxiliary light-colored thread shape at a position close to the camera and a position far from the camera before and after a direction perpendicular to the direction in which the light-colored thread-shaped member is stretched with respect to the light-colored thread-shaped member. At least one member is stretched. The auxiliary light-colored thread member is preferably stretched in parallel with the light-colored thread member.
(2) The frame member is provided with at least auxiliary dark thread-like members at positions near and far from the camera before and after a direction perpendicular to the direction in which the dark thread-like member is stretched. It is stretched one by one. The auxiliary dark thread member is preferably stretched in parallel with the dark thread member.
By providing the auxiliary thread-like member, the camera can be more accurately focused on the position of the surface of each thread-like member, that is, the sheet material.
(3) In (1) or (2), the difference in the position of the camera in the moving direction of the focal point of the light-colored thread member and the auxiliary light-colored thread member and / or the dark-colored thread member and the auxiliary dark-colored thread member The difference in position of the camera in the direction of focus movement is 0.2 to 10 mm.
(4) The frame member includes an inner frame member on which the light-colored and dark-colored thread members are stretched, and an outer frame member around the inner frame member that supports the inner frame member, and the outer frame member. The length of the long side is substantially the same as the width of the transparent sheet material, and the inner frame member is slidably disposed along a pair of plate-like members constituting the long side of the outer frame member. ing. As a result, at the appearance inspection position, each thread-like member can be arranged at any position in the width direction of the transparent sheet material under the same conditions, and the focus of the camera is accurately adjusted regardless of the position in the width direction of the camera. It can be adjusted to the position of the surface of the member, that is, the transparent sheet material.
(5) The light-colored thread-shaped member is a white thread-shaped member. In the case of reflected light, it is easiest to focus the camera.
(6) The dark-colored thread-shaped member is a black thread-shaped member. In the case of transmitted light, it is easiest to focus the camera.

  Further, the above object is a method for inspecting the appearance of a transparent sheet material by irradiating the transparent sheet material with light and taking an optical image of the transparent sheet material with transmitted light and / or reflected light with a camera, The light-colored thread-like member is mounted by the step of placing the inspection jig of the present invention at a position for inspecting the appearance of the transparent sheet material and focusing the camera on the dark-colored thread-like member by transmitted light and / or reflected light. A visual inspection of the transparent sheet material, including a step of focusing the camera on the camera and a step of placing the transparent sheet material at the visual inspection position and performing an visual inspection instead of the inspection jig. Achieved by the method.

  Thereby, the surface of the transparent sheet material is irradiated regardless of the operator or the inspection apparatus, regardless of whether the optical image by the transmitted light or the optical image by the reflected light is used. It is possible to perform an appearance inspection with reproducibility ensured by accurately focusing the camera on the position.

  In the jig for visual inspection of the transparent sheet material of the present invention, the light-colored thread-like member and the dark-colored thread-like member are stretched so as to have the same height as the surface of the transparent sheet material at the appearance inspection position. In either case of reflected light, the camera can be focused on the surface of the sheet material. Therefore, the transparent sheet material appearance inspection method of the present invention using this inspection jig allows the camera to be accurately focused on the position of the surface of the transparent sheet material regardless of the operator or the inspection apparatus, and the reproducibility. It is possible to perform an appearance inspection that is guaranteed.

FIG. 1 shows an example of the transparent sheet material appearance inspection jig of the present invention, FIG. 1 (a) is a schematic plan view, and FIG. 1 (b) is a broken line aa ′ in FIG. 1 (a). FIG. FIG. 2 is a diagram showing a monitor waveform when the camera is focused by transmitted light and reflected light using the inspection jig of FIG. FIG. 3 is a schematic plan view showing an example of a preferred embodiment of the transparent sheet material appearance inspection jig of the present invention. FIG. 4 is a schematic diagram for explaining an example of the transparent sheet material appearance inspection method of the present invention.

[Appearance inspection jig]
The transparent sheet material appearance inspection jig of the present invention irradiates the transparent sheet material with light, and captures an optical image of the transparent sheet material by transmitted light and / or reflected light with a camera. In this inspection method, the inspection jig is used for focusing the camera on the surface of the transparent sheet material. The transparent sheet material appearance inspection jig of the present invention will be described below with reference to the drawings.

  FIG. 1 shows an example of the transparent sheet material appearance inspection jig of the present invention, FIG. 1 (a) is a schematic plan view, and FIG. 1 (b) is a broken line aa ′ in FIG. 1 (a). It is a schematic sectional drawing. 1 has a rectangular frame member 103 that can be placed in place of the transparent sheet material at a position for visual inspection of the transparent sheet material, and a pair of supports between two opposing sides of the frame member 103. The white thread member 102W as a light thread member stretched horizontally by the portion 112W and the black thread member 102B as a dark thread member stretched horizontally by the pair of support portions 112B are provided.

  The white thread-like member 102W and the black thread-like member 102B have the same height as the surface of the transparent sheet material when the frame member 103 is placed at the appearance inspection position and the transparent sheet material is placed at the appearance inspection position. It is adjusted to become. For example, when the frame member 103 is placed at the appearance inspection position, the position of the bottom surface of the frame member 103 matches the position of the bottom surface of the transparent sheet material when the transparent sheet material is placed at the appearance inspection position. The height (H) from the bottom surface of the frame member 103 to the white thread-like member 102W and the black thread-like member 102B is adjusted to be the same as the thickness of the transparent sheet material. When the frame member 103 is placed at the appearance inspection position, the position of the bottom surface of the frame member 103 does not match the position of the bottom surface of the transparent sheet material when the transparent sheet material is placed at the appearance inspection position. The height (H) is adjusted in consideration of the position difference.

  When inspecting the appearance of a transparent sheet material, it is difficult to focus the camera on the transparent sheet material because the object is transparent, and variations may occur depending on the operator and the inspection apparatus. By using the appearance inspection jig of the present invention, the camera and the inspection apparatus are focused by focusing the camera on the black thread-like member 102B in the case of transmitted light and focusing the camera on the white thread-like member 102W in the case of reflected light. Regardless of this, the camera can be accurately focused on the position of the surface of the transparent sheet material. In the white thread-like member 102W, the thread-like member cannot be seen in the case of transmitted light, and the camera cannot be focused. In the black thread-like member 102B, the thread-like member cannot be seen in the case of reflected light, and the focus of the camera. Cannot be matched. In the appearance inspection jig of the present invention, it is sufficient that at least one white thread-like member 102W and black thread-like member 102B are provided, and a plurality of them may be provided. Since the camera can be focused more accurately, it is preferable that there are a plurality of white thread members 102W and a plurality of black thread members 102B. When the appearance inspection apparatus is an apparatus that uses only transmitted light or reflected light, only one of the white thread-like member 102W and the black thread-like member 102B may be provided. Considering versatility, it is preferable that both the white thread-like member 102W and the black thread-like member 102B are provided.

  The white thread-like member 102W may not be white as long as it is a light-colored thread-like member that can be detected by reflected light. A light color generally refers to a color with a high lightness and a low saturation. A white color that is most easily detected by reflected light is preferred. Further, the black thread-like member 102B may not be black as long as it is a dark thread-like member that can be detected by transmitted light. The dark color generally refers to a color having a low lightness and saturation. A black color that is most easily detected by transmitted light is preferred. These thread-like members may be anything as long as they have a diameter that allows the camera to be focused. The diameter of the thread member is preferably 0.05 to 0.3 mm.

  Further, in the appearance inspection jig shown in FIG. 1, an upper position (in the appearance inspection position) is set on the front side and the rear side in the direction orthogonal to the direction in which the white thread member 102W is stretched with respect to the white thread member 102W. Auxiliary white thread-like member 106W is stretched between a position close to the camera when placed and a lower position (position far from the camera when placed at the appearance inspection position). Each auxiliary white thread-like member 106 </ b> W is stretched horizontally by each pair of support portions 116 </ b> W provided on the frame member 103. The white thread-like member 102W and the auxiliary white thread-like member 106W may not be parallel as long as they do not intersect with each other. .

  Similarly, an upper position (a position close to the camera when placed at the appearance inspection position) on the front side and the rear side in the direction orthogonal to the direction in which the black thread member 102B is stretched with respect to the black thread member 102B. The auxiliary black thread-like member 106B at the lower position (position far from the camera when placed at the appearance inspection position) is stretched. Each auxiliary black thread-like member 106 </ b> B is stretched horizontally by each pair of support portions 116 </ b> B provided on the frame member 103. The black thread-like member 102B and the auxiliary black thread-like member 106B do not have to be parallel as long as they do not intersect with each other, but are preferably stretched in parallel because the distance does not change at any position and they are easy to use. .

  FIG. 2 is a diagram showing a monitor waveform when the focus position of the camera is adjusted using the inspection jig shown in FIG. As shown in the figure, in the case of reflected light, the monitor waveform peak of the white filamentous member 102W can be grasped more clearly by referring to the monitor waveform of the auxiliary white filamentous member 106W. In the case of transmitted light, the monitor waveform peak of the black thread-like member 102B can be grasped more clearly by referring to the monitor waveform of the auxiliary black thread-like member 106B.

  In the appearance inspection jig of the present invention, the auxiliary white thread-like member 106W and the auxiliary black thread-like member 106B may be omitted, but as described above, the white thread-like member 102W and the black thread-like member 102B are more accurately connected to the camera. It is preferable that these auxiliary thread-like members are provided in terms of easy focusing. A plurality of auxiliary thread-like members may be provided.

  The difference (d) between the positions of the white thread-like member 102W and the auxiliary white thread-like member 106W in the vertical direction (that is, the camera's focal movement direction) and / or the vertical direction of the black thread-like member 102B and the auxiliary black thread-like member 106B (ie The position difference (d) in the camera's focus movement direction) is not particularly limited, and is set at an interval that can be easily referred to when the focus position is adjusted to each thread-like member. Preferably, it is 0.2-10 mm, More preferably, it is 0.2-2 mm.

  Further, the difference between the positions of the white thread member 102W and the auxiliary white thread member 106W in the direction perpendicular to the direction in which the white thread member 102W is stretched, and / or the black thread member of the black thread member 102B and the auxiliary black thread member 106B. There is no particular limitation on the position difference in the direction orthogonal to the direction in which 102B is stretched. Preferably it is 5-20 mm, More preferably, it is 5-10 mm.

  The frame member 103 may be made of any material as long as the frame member 103 has robustness that does not deform even when each thread-like member is stretched. In consideration of the thickness of the transparent sheet material, it is preferable to use a metal having a fastness even if it is thin.

  FIG. 3 is a schematic plan view showing an example of a preferred embodiment of the transparent sheet material appearance inspection jig of the present invention. In FIG. 3, the frame member includes an inner frame member 203 and an outer frame member 223 around the inner frame member 203 that supports the inner frame member 203. In the inner frame member 203, as in the case of FIG. 1, a white thread member 202W as a light thread member is horizontally stretched by a pair of support portions 212W, and a black thread member 202B as a dark thread member is a pair of support portions 212B. Is stretched horizontally. Further, the auxiliary white thread-like member 206W and the auxiliary black thread-like member 206B are also provided in the same manner as in FIG. On the other hand, the outer frame member 223 includes a pair of plate-like members 223L constituting long sides and a pair of plate-like members 223S constituting short sides, and the length (L) of the long sides performs an appearance inspection. It is set to be substantially the same as the width of the transparent sheet material. The inner frame member 203 is disposed inside the outer frame member 223 so as to be slidable in the arrow direction along the pair of plate-like members 223L. The slide moving mechanism may have any configuration. For example, there is a mechanism in which a rail-shaped groove is formed on the side surface of the plate-shaped member 223L, and the inner frame member 203 slides along the groove. In FIG. 3, the inner frame member 203 can be fixed at an arbitrary position of the plate-like member 223 </ b> L by the holding member 213 and the fastener 214.

  According to the appearance inspection jig of FIG. 3, when the outer frame member 223 is placed at the appearance inspection position of the transparent sheet material, it can be placed with the same width as when the transparent sheet material is placed at the appearance inspection position. Then, the white frame member 202W and the black thread member 202B are arranged under the same conditions at any position in the width direction of the transparent sheet material at the appearance inspection position by sliding the inner frame member 203 and arranging it at an arbitrary position. be able to. Therefore, regardless of the position of the camera of the appearance inspection apparatus, the camera can be accurately focused on the position of the surface of each filamentous member, that is, the transparent sheet material, under the same conditions.

[Appearance inspection method for transparent sheet]
The appearance inspection method for a transparent sheet material according to the present invention is an inspection method by irradiating light to a transparent sheet material and taking an optical image of the transparent sheet material by transmitted light and / or reflected light with a camera. Is used, the transparent sheet material appearance inspection jig of the present invention is used.

  FIG. 4 is a schematic diagram for explaining an example of the appearance inspection method for the transparent sheet material of the present invention. 4 includes a camera 41, an appearance inspection table 51, and a transmitted light source 61 (FIGS. 4A and 4C) and / or a camera 42, an appearance inspection table 52, and a reflection. It has the light source 62 for light (FIG.4 (b), (d)). The camera 41 and / or the camera 42 may be anything. A normal line sensor camera or area sensor camera can be used. The appearance inspection table 51 and / or the appearance inspection table 52 are usually provided by being incorporated in a part of a conveying device that conveys the transparent sheet material. The light source 61 for transmitted light and / or the light source 62 for reflected light only needs to be bright enough to detect a defect in the transparent sheet material by visual inspection. You may use the light source which passed the polarization process and the slit as needed.

  First, the appearance inspection jig 31 of the transparent sheet material of the present invention is placed on the appearance inspection table 51. At this time, the transparent sheet material is accurately placed at an appearance inspection position for appearance inspection. In the appearance inspection jig 31, a white thread member 32 W as a light thread member and a black thread member 32 B as a dark thread member are stretched on the frame member 33 in the same manner as described above for the appearance inspection jig. Yes. The position A in the camera focal point moving direction (height direction in FIG. 4) of the white thread member 32W and the black thread member 32B is the transparent sheet material when the transparent sheet material to be inspected is placed at the appearance inspection position. It is adjusted to the same height as the surface.

  In FIG. 4A, the camera 41 is focused on the black thread-like member 32B by the transmitted light at the appearance inspection position including the transmitted light source 61. In FIG. 4B, the camera 42 is focused on the white thread-like member 32W by the reflected light at the appearance inspection position including the reflected light source 62. Thereby, at each appearance inspection position, the focus of the camera can be accurately adjusted with good reproducibility to the position of the surface of the transparent sheet material to be inspected. Thereafter, in place of the appearance inspection jig 31, the transparent sheet material 11 is placed at the appearance inspection position of the appearance inspection table 51, and the appearance inspection is performed by transmitted light (FIG. 4C), and / or the transparent sheet material. 11 is placed at the appearance inspection position of the appearance inspection table 52, and the appearance is inspected by reflected light (FIG. 4D).

  According to the method for inspecting the appearance of a transparent sheet material of the present invention, it is possible to irradiate the transparent sheet material with light and use either an optical image by the transmitted light or an optical image by the reflected light. Regardless of the inspection device, it is possible to perform an appearance inspection with reproducibility ensured by accurately focusing the camera on the position of the surface of the transparent sheet material.

  In addition, this invention is not limited to the structure of said embodiment, A various deformation | transformation is possible within the range of the summary of invention.

  According to the present invention, it is possible to accurately perform an appearance inspection in a manufacturing process or product inspection of a transparent sheet material used for an optical filter for display or the like, and it is possible to provide a high-quality transparent sheet material.

11 Transparent sheet material 31 Appearance inspection jig 32W, 102W, 202W White thread member 32B, 102B, 202B Black thread member 33, 103 Frame member 41, 42 Camera 51, 52 Appearance inspection table (conveyance device)
61 Light source for transmitted light 62 Light source for reflected light 106W, 206W Auxiliary white thread member 106B, 206B Auxiliary black thread member 112W, 212W White thread member support part 112B, 212B Black thread member support part 116W, 216W Auxiliary white Threaded member support part 116B, 216B Auxiliary black threaded member support part 203 Inner frame member 213 Holding member 214 Fastener 223 Outer frame member 223L, 223S Plate member

Claims (8)

In the method of inspecting the appearance of the transparent sheet material by irradiating the transparent sheet material with light and taking an optical image of the transparent sheet material by the transmitted light and / or reflected light with the camera, the camera is focused on the transparent sheet material. An inspection jig used to match the surface,
A rectangular frame member that can be placed in place of the transparent sheet material at a position for visual inspection of the transparent sheet material, and the same surface as the surface of the transparent sheet material when the frame member is placed at the visual inspection position An inspection jig comprising at least one light-colored thread-like member and / or at least one dark-colored thread-like member stretched on the frame member so as to have a height.   The frame member has at least auxiliary light-colored thread members at positions near and far from the camera before and after the light-colored thread-shaped member in a direction perpendicular to the direction in which the light-colored thread member is stretched. The inspection jig according to claim 1, wherein the inspection jig is stretched one by one.   The frame member has at least one auxiliary dark thread-like member at a position close to the camera and at a position far from the camera before and after the dark thread-like member in a direction perpendicular to the direction in which the dark thread-like member is stretched. The inspection jig according to claim 1, wherein the inspection jig is stretched.   The difference in position of the camera in the focal movement direction of the light-colored thread member and the auxiliary light-colored thread member, and / or the difference in position of the dark-colored thread member and the auxiliary dark-colored thread member in the focus movement direction of the camera, The inspection jig according to claim 2 or 3, wherein the inspection jig is 0.2 to 10 mm. The frame member comprises an inner frame member on which the light-colored thread-like member and dark-colored thread-like member are stretched, and an outer frame member around the inner frame member that supports the inner frame member;
The length of the long side of the outer frame member is substantially the same as the width of the transparent sheet material,
The inspection jig according to any one of claims 1 to 4, wherein the inner frame member is slidably disposed along a pair of plate-like members constituting the long side of the outer frame member. .   The inspection jig according to claim 1, wherein the light-colored thread-shaped member is a white thread-shaped member.   The inspection jig according to claim 1, wherein the dark thread-like member is a black thread-like member. A method for inspecting the appearance of a transparent sheet material by irradiating light to the transparent sheet material and capturing an optical image of the transparent sheet material by transmitted light and / or reflected light with a camera,
Mounting the inspection jig according to any one of claims 1 to 7 at a position for visual inspection of the transparent sheet material, and focusing the camera on the dark-colored filamentous member by transmitted light; Or, the step of focusing the camera on the light-colored thread-like member by reflected light, and the step of inspecting the appearance by placing a transparent sheet material at the appearance inspection position instead of the inspection jig,
A method for inspecting the appearance of a transparent sheet material, comprising:

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