TWI607212B - Image generation device, defect inspection device, and defect inspection method - Google Patents

Description

Image generating device, defect inspection device, and defect inspection method

The present invention relates to an image generating apparatus that generates image data for inspecting a defect of a sheet-shaped formed body, a defect inspecting apparatus including the image generating apparatus, and a defect inspecting method.

A method of using a camera has been known as a method for inspecting defects of a sheet-like formed body such as a polarizing film or a retardation film. For example, in Japanese Laid-Open Patent Publication No. 2007-333563 (Patent Document 1), a sheet-like molded body is irradiated with light by a light source, and transmitted through the sheet-shaped molded body by a line sensor camera. The light image is thereby used to inspect the defects of the sheet-shaped formed body. Further, a method of inspecting a defect of a sheet-shaped formed body by photographing a reflected light image instead of photographing a transmitted light image has been known.

An example of a method of detecting whether or not a dot-shaped concave defect is generated in a sheet-shaped formed body by a line sensor camera will be described with reference to FIG. The sheet-like formed body L shown in Fig. 10 has a pit-shaped concave defect L _{1 in the} center in the width direction X thereof. The sheet-like formed body L is conveyed to one side in the longitudinal direction Y. As a result, as shown in FIGS. 10( a ) to 10 ( c ), the concave defects L _{1 are} sequentially moved to one side in the longitudinal direction Y.

As shown in FIGS. 10(a) to 10(c), a bright portion L ₂ and a dark portion L ₃ are formed in the sheet-like formed body L by a light source (not shown) extending in the width direction X. The position of the light source is fixed, and by moving the sheet-shaped formed body L, the position of the bright portion L ₂ is sequentially moved on the other side of the sheet-shaped formed body L in the longitudinal direction Y. A line sensor camera (not shown) is provided so that the vicinity of the boundary line between the bright portion L ₂ and the dark portion L _{3 is the} imaging range B. As long as the line sensor camera, the position of the light source with respect to the fixed, the sheet material L is stably conveyed, and L recessed _{defect. 1} is not located near the imaging area, FIG. 10 (a) and 10 (C), The images near the boundary between the bright portion L ₂ and the dark portion L _{3 are} the same, and the images G ₁ and G ₃ obtained by the line sensor camera are also the same. However, in FIG. 10 (b), the concave defect in case L ₁ is located in the vicinity of the imaging region, the turn of the image line L ₃ L ₂ near the bright portion and the dark portion due to the recessed defect is generated change L _1, which is As a result, unlike the images G ₁ and G ₃ , the dark portion L ₃ is captured in the image G ₂ obtained by the line sensor camera. Thus, FIG. 10 (d), the acquisition of the image by using the line sensor camera are sequentially synthesized, the examination position can be synthesized represents L of the concave defect ₁ G ₄ by the dark image portion.

The method of detecting the defect described with reference to FIG. 10 is based on the assumption that the sheet-like molded body L is stably conveyed as described above. However, there is a case where the sheet-like formed body L is shaken during transportation, and it is not necessarily stably conveyed. When the sheet-like formed body L is shaken during conveyance, there is a case where the positional relationship between the sheet-like formed body L and the line sensor camera and the light source changes, and the defect cannot be smoothly found by the above-described defect inspection method.

In the present invention, the state in which the sheet-like molded body is swayed, for example, when the sheet-shaped formed body is conveyed in the horizontal direction, is a state in which part or all of the sheet-like formed body is vigorously rocked up and down, for example, When the sheet-like formed body is conveyed in the vertical direction, a part or all of the sheet-like formed body is violently shaken left and right.

The case where the sheet-like formed body L is shaken will be described with reference to Fig. 11 . In Figs. 11(a) and 11(b), no sway occurs, and the same state as in Figs. 10(a) and 10(b) is shown, and sway occurs in Fig. 11(c). FIG. 11 (c), the fluctuation when the sheet material L, even if the concave defect is not _{located. 1} L photographing region, bright image of the vicinity of the portion L ₂ and L ₃ at the turn of the dark portion caused by a fluctuation boundaries will be generated As a result, there is a case where, unlike the images G ₁ and G ₂ , the dark portion L ₃ is largely captured in the image G ₅ obtained by the line sensor camera. When in this case, as shown in FIG 11 (d) shall be as shown in the dark portion represents the check of the position of _a concave defect image L G, L ₆ generates _a concave defect unrelated to the dark portion, and there is determined erroneously There is also a flaw in the position unrelated to the concave defect L ₁ . Further, at the state of FIG 11 is different from the rock, is also present in the concave defect is located near the L ₁ region captured image acquired by the line sensor camera does not shoot the case where the dark portion of L _3, while the error It is judged that there is no defect in the sheet-like formed body L.

The present invention has been made to solve such a problem, and an object of the invention is to provide an image data for inspecting defects of a sheet-shaped formed body, and to prevent erroneous determination of the presence or absence of defects due to shaking of the sheet-shaped formed body or the like. An image generating device, a defect inspection device including the image generating device, and a defect inspection method.

The present invention provides an image generating apparatus that generates image data for inspecting a defect of a sheet-shaped formed body, and includes: a conveying portion that conveys the sheet-shaped formed body along a length direction of the sheet-shaped formed body; And a light source that linearly extends in the width direction of the sheet-like molded body, wherein the sheet-shaped molded body is irradiated with light by the light source, and the image capturing unit performs an image capturing operation on the sheet-shaped formed body during conveyance. Generating a two-dimensional image data representing a two-dimensional image, and performing a plurality of shots on the sheet-shaped formed body in a position corresponding to a bright portion of the light source and a dark portion having a lower brightness than the bright portion in the two-dimensional image And an inspection image data generation unit that generates inspection image data from a plurality of two-dimensional image data generated by the imaging unit, and includes: a boundary extraction unit that extracts each two-dimensional image a boundary line portion between the bright portion and the dark portion in each of the two-dimensional images represented by the data; and a re-extraction portion that connects the boundary portions to form an apparent boundary line on the apparent boundary line Appear The sharp peaks disappearance embodiment, the turn of the apparent boundary smoothing, configured to extract from the two-dimensional image data obtained by the smoothed boundaries of the original turn of pixels; and a synthesizing unit that generates one-dimensional image data including pixels extracted by the re-extraction unit, and synthesizes a plurality of one-dimensional image data obtained from the plurality of two-dimensional image data in the same manner to generate an inspection image data.

Moreover, the present invention provides a defect inspection apparatus including: the image generation device; and a display unit that displays an inspection image data generated by the inspection image data generation unit of the image generation device The image.

Further, the present invention provides a defect inspection method for inspecting defects of a sheet-shaped formed body, and comprising: a photographing step of illuminating the light source by a light source extending linearly in a width direction of the sheet-shaped formed body The sheet-shaped molded body is irradiated with light, and the sheet-like formed body is imaged in the longitudinal direction of the sheet-like formed body, and the sheet-shaped molded body is imaged to generate two-dimensional image data representing the two-dimensional image. And the plurality of imaging operations are performed on the sheet-shaped formed body corresponding to the bright portion of the light source and the dark portion having a lower brightness than the bright portion in the two-dimensional image; and the boundary extraction step is performed by the above-mentioned shooting Each of the two-dimensional image data generated in the step represents a boundary line between the bright portion and the dark portion in each of the two-dimensional images; and a re-extraction step of connecting the boundary portions to form an apparent boundary The line smoothes the apparent boundary line in the manner that the sharp peak appearing on the apparent boundary line disappears, and extracts the original result obtained by smoothing from the two-dimensional image data. a pixel of a line; a synthesis step of generating a plurality of one-dimensional image data obtained by including one of the pixels extracted in the above-mentioned re-extraction step, and synthesizing the plurality of two-dimensional image data in the same manner And generating image data for inspection; and displaying a step of displaying an image represented by the image data for inspection generated in the above-described synthesis step.

According to the present invention, in the image forming apparatus, a plurality of two-dimensional image data are generated by performing a plurality of imaging operations on the sheet-shaped molded body in a state where light is applied to the sheet-shaped molded body during conveyance. Further, a boundary line portion between the bright portion and the dark portion in each of the two-dimensional images indicated by the respective two-dimensional image data is extracted. Then, the boundary line portions are connected to form an apparent boundary line, and the apparent boundary line is smoothed in such a manner that the sharp peak appearing on the apparent boundary line disappears. The pixels constituting the original boundary line obtained by smoothing in this manner are re-extracted from the two-dimensional image data, and one-dimensional image data including pixels constituting the original boundary line is generated. The inspection image data is generated by synthesizing a plurality of one-dimensional image data obtained from a plurality of two-dimensional image data in the same manner.

When the sheet-like formed body is defective, when the sheet-shaped formed body is stably conveyed and the defect is located in the vicinity of the boundary portion, the apparent boundary line becomes a curved curve in which a sharp peak appears due to the defect. . Therefore, the original boundary line obtained by smoothing the apparent boundary line is different from the apparent boundary line. Further, when the sheet-like formed body is defective, when the sheet-shaped formed body is shaken during conveyance and the defect is not located in the vicinity of the boundary portion, the apparent boundary line becomes due to the sway of the sheet-shaped formed body. A gentle curve. Therefore, the original boundary line obtained by smoothing the apparent boundary line is a curve substantially the same as the apparent boundary line or the same curve as the apparent boundary line.

Thereby, one-dimensional image data including pixels constituting the original boundary line is generated from each two-dimensional image data, and a plurality of one-dimensional image data obtained in this manner are synthesized and used as inspection image data. The inspection image data indicating the position of the defect by the positional relationship between the bright part and the dark part can be generated. As a result, it is possible to determine whether or not the sheet-shaped formed body is defective based on the inspection image data, and it is possible to prevent an erroneous determination of the presence or absence of the defect due to the sway of the sheet-shaped formed body.

Moreover, according to the present invention, the defect inspection apparatus includes the image generation apparatus of the present invention described above and a display unit. The display unit displays an image indicated by the inspection image data generated by the inspection image data generating unit of the image generating device. By observation based on the display By checking the image displayed by the image data, it is possible to determine whether or not there is a defect, and it is possible to prevent the occurrence of an erroneous determination of the presence or absence of the defect due to the shaking of the sheet-shaped formed body.

Further, according to the present invention, in the image capturing step, the sheet-like molded body is subjected to a plurality of imaging operations in a state in which light is applied to the sheet-shaped molded body during conveyance, and a plurality of two-dimensional images are generated. Like information. Further, in the boundary extraction step, a boundary line portion between the bright portion and the dark portion in each of the two-dimensional images indicated by the respective two-dimensional image data is extracted. Then, in the re-extraction step, the boundary line portions are connected to form an apparent boundary line, and the apparent boundary line is smoothed in such a manner that the sharp peak appearing on the apparent boundary line disappears. . The pixels constituting the original boundary line obtained by smoothing in this manner are re-extracted from the two-dimensional image data. Further, in the synthesizing step, generating one-dimensional image data including one of the pixels constituting the original boundary line, and synthesizing a plurality of one-dimensional image data obtained from the plurality of two-dimensional image data in the same manner, and generating The positional relationship between the bright part and the dark part indicates the image data for inspection of the position of the defect, and in the display step, the image indicated by the image data for inspection is displayed. By observing the image represented by the inspection image data displayed in the display step, it is possible to determine whether or not there is a defect, and it is possible to prevent an erroneous determination of the presence or absence of the defect due to the sway of the sheet-shaped molded body or the like.

1‧‧‧Image generating device

11‧‧‧Transportation Department

12‧‧‧Lighting Department

13‧‧‧Photography Department

14‧‧‧Information processing device

21‧‧‧Display Department

100‧‧‧ Defect inspection device

141‧‧‧Image data generation department for inspection

1411‧‧The Border Extraction Department

1412‧‧‧Re-extraction department

1413‧‧‧Combination Department

A‧‧‧ two-point chain

B‧‧‧ Shooting range

G ₁ ‧‧‧ image

G ₂ ‧‧‧ image

G ₃ ‧‧‧ image

G ₄ ‧‧‧Image for inspection

G ₅ ‧‧‧ image

G ₆ ‧‧‧Image for inspection

j ₁ ‧‧ ‧ boundary line

j ₂ ‧‧ ‧ boundary line

j ₃ ‧‧ ‧ boundary line

j ₄ ‧‧ ‧ boundary line

K‧‧‧Fabric shaped body

K ₁ ‧‧‧ concave defect

K ₂ ‧‧ ‧Ministry

K ₃ ‧‧‧Dark Department

L‧‧‧Fabric shaped body

L ₁ ‧‧‧ concave defect

L ₂ ‧‧ ‧Ministry

L ₃ ‧‧‧Dark Department

P ₁ ‧ ‧ pixels

P ₂ ‧ ‧ pixels

P ₃ ‧ ‧ pixels

P ₄ ‧ ‧ pixels

P ₅ ‧ ‧ pixels

P ₆ ‧ ‧ pixels

P ₇ ‧ ‧ pixels

P ₈ ‧ ‧ pixels

P ₉ ‧ ‧ pixels

S1‧‧‧ steps

S2‧‧‧ steps

S3‧‧‧ steps

S4‧‧‧ steps

S5‧‧ steps

X‧‧‧ direction

Y‧‧‧ direction

Fig. 1 is a perspective view showing a defect inspection apparatus 100 of the present invention.

Fig. 2 is a block diagram showing the defect inspection apparatus 100 of the present invention.

Fig. 3 is a view showing the steps of the defect inspection method of the present invention.

4(a) to 4(c) are views showing the state of the sheet-shaped formed body K.

5(a) to 5(c) are views showing an image obtained by photographing the sheet-shaped formed body K.

6(a) to 6(d) are views showing an image obtained by photographing the sheet-shaped formed body K.

7(a)-(c) show images obtained by photographing the sheet-shaped formed body K. Figure.

Fig. 8 is a view showing an image obtained by photographing the sheet-shaped formed body K.

9(a) to 9(e) are diagrams for explaining a specific example of processing by the re-extraction unit 1412.

FIGS. 10(a) to 10(d) are views for explaining an example of a method of detecting whether or not a dot-shaped concave defect is formed in the sheet-like formed body L by a line sensor camera.

11(a) to 11(d) are views for explaining a case where the sheet-like formed body L is shaken.

Hereinafter, an image generating apparatus, a defect inspecting apparatus, and a defect inspecting method of the present invention will be described. Fig. 1 is a perspective view showing a defect inspection apparatus 100 of the present invention. Fig. 2 is a block diagram showing the defect inspection apparatus 100 of the present invention. Fig. 3 is a view showing the steps of the defect inspection method of the present invention. The defect inspection device 100 is a device for inspecting a defect of a sheet-shaped formed body, and is a device for inspecting the defect, that is, the method of the defect inspection method of the present invention. The defect inspection apparatus 100 can inspect an optical film such as a polarizing film or a retardation film which is a sheet-shaped molded body, and is particularly suitable for inspection of a long optical film which is wound into a mesh shape for storage and transportation.

The sheet-like formed body contains, for example, a resin such as a thermoplastic resin. For example, a sheet-shaped molded body containing a resin is formed by subjecting a thermoplastic resin extruded from an extruder to a surface of a roll to impart smoothness or gloss to the surface, and to convey the surface. The cooling side of the roll is taken up by a take-up roll. The thermoplastic resin which becomes a material of the sheet-shaped formed body is, for example, a methacrylic resin, a methyl methacrylate-styrene copolymer, a polyolefin such as polyethylene or polypropylene, a polycarbonate, a polyvinyl chloride, a polystyrene, or a poly Vinyl alcohol, cellulose triacetate resin, and the like. The sheet-like formed body may contain only one of the thermoplastic resins, or may be a plurality of layers of the thermoplastic resins.

The sheet-shaped formed body may have any thickness. For example, the sheet-like formed body may be a relatively thin thickness such as a polarizing film or a retardation film, which is generally called a "film", and may also be It is a relatively thick thickness as commonly referred to as a "plate".

Examples of the defects of the sheet-like formed body include dot-shaped defects (point defects) such as bubbles, fisheye, foreign matter, tire marks, dents, and scratches generated during molding, and creases. A so-called crack (knick) which is caused by the like, and a linear defect (line defect) such as a so-called original stripe which is caused by a difference in thickness.

As shown in FIGS. 1 and 2, the defect inspection apparatus 100 includes the image generation apparatus 1 and the display unit 21 of the present invention. The image generation device 1 of the defect inspection device 100 includes a conveyance unit 11 that conveys the sheet-shaped formed body K to one side in the longitudinal direction (hereinafter referred to as "Y direction"), and the light irradiation unit 12 has The light source extending linearly in the width direction of the sheet-like formed body K (hereinafter referred to as "X direction"), and the imaging unit 13 performs an imaging operation on the sheet-shaped formed body K to generate a two-dimensional image representing a two-dimensional image. Image data; and information processing device 14. The information processing device 14 includes an inspection image data generation unit 141 including a boundary extraction unit 1411, a re-extraction unit 1412, and a synthesizing unit 1413. The information processing device 14 also includes a transport control unit (not shown) that controls the operation of the transport unit 11. The information processing device 14 is realized by a PC (Personal Computer) or the like. Furthermore, the inspection image data generating unit 141 in the information processing device 14 can also use an FPGA (Field-programmable gate array) or a GPGPU (General-purpose computing on graphics processing units). The processor or the like is implemented by an image processing board or an internal hardware of the imaging unit 13.

As shown in FIG. 3, the defect inspection method of the present invention includes a shooting step S1, a boundary extraction step S2, a re-extraction step S3, a synthesis step S4, and a display step S5.

In the imaging step S1, the sheet-like molded body is conveyed to one side in the Y direction by the transport unit 11 while the sheet-like molded body K is irradiated with light by the light source of the light-irradiating portion 12, and is in a two-dimensional view. The imaging unit 13 performs a plurality of imaging operations on the sheet-shaped formed body K by the imaging unit 13 so as to include a bright portion corresponding to the light source of the light-irradiating portion 12 and a dark portion having a lower brightness than the bright portion.

The boundary extraction step S2 is a step of extracting from the bright portion to the dark portion in each two-dimensional image represented by each two-dimensional image data generated by the imaging unit 13 in the imaging step S1 by the boundary extraction unit 1411. The boundary line portion or the dark portion becomes the boundary line portion of the Ming Dynasty.

The re-extraction step S3 is a step of connecting the boundary line portions obtained in the boundary extraction step S2 by the re-extraction portion 1412 to form an apparent boundary line on which the sharp peak appears on the apparent boundary line. The disappearing method smoothes the apparent boundary line, and extracts pixels constituting the original boundary line obtained by smoothing from the two-dimensional image data.

The synthesizing step S4 is a step of: generating, by the synthesizing unit 1413, one-dimensional image data of the pixels extracted by the re-extracting unit 1412 in the re-extracting step S3, and synthesizing the two-dimensional image data obtained in the same manner from the plurality of two-dimensional image data. The plurality of one-dimensional image data is generated to generate inspection image data indicating the position of the concave defect or the convex defect by the change in brightness. For example, in the boundary line portion when the bright portion is changed from the bright portion, the position of the concave defect is indicated by the portion where the brightness is dark.

The display step S5 is a step of displaying the inspection image indicated by the inspection image data generated by the synthesizing unit 1413 in the synthesis step S4 on the display unit 21.

Each of steps S1 to S5 will be described with reference to Figs. 4 to 8 . 4 is a view showing a state of the sheet-like formed body K, and FIGS. 5 to 8 are views showing an image obtained by photographing the sheet-shaped formed body K. As shown in Fig. 4, a concave defect K _{1 having} a bit shape is generated in the sheet-like formed body K. Further, the sheet-like formed body K is conveyed to one side in the Y direction in the order shown in Figs. 4(a), 4(b), and 4(c).

As shown in Fig. 4 (a), the light source of the light-irradiating portion 12 extending linearly in the X direction causes the sheet-shaped molded body K to have a bright portion K ₂ extending linearly in the X direction, and the brightness is higher than that. bright portion of a dark portion of low K ₂ K _3. The bright portion K ₂ is linearly extended when the sheet-shaped formed body K is stably conveyed, and the sheet-shaped formed body K is not shaken, and the concave defect K _{1 is} not located in the vicinity of the bright portion K ₂ . 4 (b), when the concave defect K ₁ K ₂ is located in the bright portion, the bright portion K ₂ is no longer a linear shape as shown in FIG. FIG. 4 (c) and FIG. 4 (a) and FIG. 4 (b) is different in the case shown in conveying the sheet material K of shaking, when in this case, although concave defects K ₁ K is not near the bright portion _2, However, due to the sway of the sheet-like formed body K, the bright portion K _{2 is} no longer linear.

The two-dot chain line A shown in FIG. 4 indicates the imaging range of the imaging unit 13. Shooting at step S1, the imaging unit 13, and bright portions K ₂ K adjacent to the bright portions of the dark portion ₂ K ₃ enters into the imaging range of the mode for photographing operation. The two-dimensional image as the result of the photographing in FIG. 4(a) is the two-dimensional image shown in FIG. 5(a), and the two-dimensional image as the photographing result in FIG. 4(b) is FIG. 6(a). The two-dimensional image shown as the two-dimensional image of the photographing result in Fig. 4(c) is the two-dimensional image shown in Fig. 7(a). Each of the pixels constituting each of the two-dimensional images is assigned an X coordinate value which becomes an integer which continuously increases toward the right side in the X direction in FIG. 5, FIG. 6, and FIG. 7, and continuously changes toward the lower side in the Y direction. The Y coordinate value of the large integer. In addition, in FIGS. 5(a), 6(a), and 7(a), the bright portion is a white portion, and the dark portion is a diagonal portion.

In the boundary extraction step S2, the boundary extraction unit 1411 extracts the boundary line portion from each of the two-dimensional images shown in FIGS. 5(a), 6(a), and 7(a). The boundary line portion is, for example, a portion of a portion of the bright portion in the two-dimensional image that changes to a dark portion that is adjacent to the bright portion and has a larger Y coordinate value than the bright portion. The boundary line portion can be extracted by a previously known edge extraction method. For example, for the data of one row of pixel rows in the Y direction in the two-dimensional image, the pixel having the smallest value of the Y coordinate is sequentially set as the pixel of interest, as long as the luminance value of the pixel whose Y coordinate value is larger than the pixel of interest is 1 When the brightness value of the pixel of interest is larger than a certain threshold value, a pixel having a Y coordinate value larger than the target pixel may be extracted as a pixel constituting the boundary line portion. Hereinafter, the pixels extracted in this way are referred to as extracted pixels. The boundary line portions formed by the pixels extracted from the respective two-dimensional images shown in FIGS. 5(a), 6(a), and 7(a) are shown in FIG. 5(b) and FIG. 6(b), respectively. And Figure 7(b). An apparent boundary line is obtained by connecting the boundary lines of adjacent pixel rows.

When there is a defect near the boundary between the bright part and the dark part, the apparent boundary line obtained in this way is affected by the defect and a sharp peak appears. Re-extract Step S3 is a step of obtaining a boundary line portion which forms an original boundary line after the influence of the defect is excluded. Therefore, in the re-extraction step S3, first, the apparent boundary line is smoothed so that the apparent boundary line has no sharp peaks. For example, a peak whose peak height is a specific multiple of the width of the peak (for example, 1/2 times to 2 times) is regarded as a sharp peak, and the line of the bottom side of the peak is set such that the sharp peak disappears. The original boundary line. In the re-extraction step S3, the pixels constituting the original boundary line obtained in this way are extracted from the original two-dimensional image data. Hereinafter, the pixels extracted in this way are referred to as re-extracted pixels.

In the case where there is no defect near the boundary line between the bright portion and the dark portion, the apparent boundary line obtained in the boundary extraction step S2 does not have a sharp peak, thereby obtaining the original in the re-extraction step S3. The boundary line is the same as the apparent boundary line obtained in the boundary extraction step S2. Therefore, there is no defect near the boundary line between the bright portion and the dark portion, and when the apparent boundary line obtained in the boundary extraction step S2 does not have a sharp peak, the re-extraction step can be substantially skipped. S3.

In FIGS. 5(b), 6(b), and 7(b), the apparent boundary lines j ₁ , j ₂ , and j ₃ are respectively indicated by two-dot chain lines. The boundary line j ₁ shown in Fig. 5(b) is a straight line, and the boundary line j ₃ shown in Fig. 7(b) is a gentle curve without a sharp peak. Therefore, for the two-dimensional image shown in FIG. 5(a) and the two-dimensional image shown in FIG. 7(a), it is not necessary to perform re-extraction of pixels in the re-extraction step S3 to form an apparent boundary line. The pixel becomes a pixel that constitutes the original boundary line. On the other hand, the boundary line j ₂ shown in FIG. 6(b) is a curve having a sharp peak. The curve obtained by smoothing the boundary j _{2 of} the distortion is a straight line j ₄ indicated by a broken line in Fig. 6(b). Therefore, the original boundary line is the same as j _{2 which is the} apparent boundary line at the X coordinate values 1 to 4 and 8 to 10, and becomes the straight line j ₄ at the X coordinate value 5 to 7. In the re-extraction step S3, the data constituting the pixels of the obtained original boundary line is extracted from the original two-dimensional image data. The re-extracted pixels extracted from the two-dimensional image shown in Fig. 6(a) are shown in Fig. 6(c). The pixel of the X coordinate value 5 to 7 in the re-extraction pixel corresponds to the boundary line portion which is distorted due to the defect portion included in the original two-dimensional image data, and has a brightness value which is brighter or darker than other pixels.

In the synthesizing step S4, the one-dimensional image data representing the one-dimensional image is generated by the re-extracting pixels extracted from the respective two-dimensional images by the re-extracting portion 1412 in the re-extracting step S3 by the synthesizing portion 1413. The one-dimensional image data is obtained by re-extracting the X coordinate value of the pixel and the brightness value to establish corresponding image data. 5(c), 6(d), and 7(c) show the respective two-dimensional images corresponding to those shown in Figs. 5(a), 6(a), and 7(a). One-dimensional image.

Further, in the synthesizing step S4, a plurality of one-dimensional image data obtained from a plurality of pieces of two-dimensional image data in the same manner are synthesized to generate inspection image data. The synthesis is performed by the method of having a smaller Y coordinate value corresponding to one of the two-dimensional image data generated by the imaging unit 13 first, corresponding to the two-dimensional image generated by the imaging unit 13. One of the image data has a larger Y coordinate value, and the X coordinate value of each one-dimensional image data remains unchanged, and a plurality of one-dimensional image data are continuously arranged in the Y direction. And combined. FIG. 8 shows an inspection image obtained by representing one-dimensional image data of one of the dimensional images shown in FIGS. 5(c), 6(d), and 7(c). The synthetic inspection is represented by image data.

In the synthesizing step S4, each one-dimensional image data may also be binarized. The luminance value which becomes the threshold of binarization is set so that the pixel of the bright part in the one-dimensional image and the pixel of the dark part in the one-dimensional image are binarized and become mutually different values. For example, the threshold of binarization is the sum of the maximum luminance value and the minimum luminance value in the one-dimensional image data. In the case of binarization, after the one-dimensional image data is binarized, the image data for inspection is synthesized. Furthermore, the order of binarization is not limited to the above-described order, and the image data for inspection may be generated by binarizing the two-dimensional image data synthesized after synthesizing the one-dimensional image data.

In the display step S5, the inspection image indicated by the inspection image data is displayed on the display unit 21. The inspection image is based on, for example, the brightness value of each pixel, and the dark portion becomes black. The display unit 21 is displayed in a manner that the color and the bright portion are white.

According to such embodiment 100 by the defect inspection apparatus comprising the defect inspection method of the steps S1 ~ S5, the sheet-K in the molded article produced in the recess when the case of the defective K ₁ in FIG. 4 (b) as shown in the when the sheet-shaped molded body K is conveyed stably and concave defect portion is located near the boundary line, because of the concave defect caused by K ₁ in FIG. 6 (b) as shown in the turn of the apparent distortion of a curved line j _2. Therefore, the pixels in the two-dimensional image constituting the straight line j ₄ obtained by smoothing the boundary line j ₂ include dark portions as shown in FIG. 6(c). Further, in the sheet material to yield K K concave defects of _a case, in FIG. 4 (c) as shown in K of the sheet material conveyed in the concave defect and shaking K is not near _a boundary line portion When the sheet-like formed body K is shaken, the apparent boundary line j ₃ becomes a gentle curve as shown in Fig. 7(b). Thus, j is approximately the same as the profile of the boundary line ₃ of the smoothing curve obtained with the boundary line j _3, the same or boundary line j of curve _3, corresponding to the pixels within the two-dimensional image of the curve does not largely The deviation from the boundary portion which is a part of the bright portion is the same as that shown in Fig. 7(b). Thereby, each of the one-dimensional image data shown in FIGS. 6(d) and 7(c) is generated from the respective portions, and a plurality of one-dimensional image data are synthesized and used as inspection image data. It is possible to generate inspection image data indicating the position of the defect by the dark portion. As a result, it is possible to determine the presence or absence of a defect by observing the inspection image shown in FIG. 8 displayed based on the inspection image data, and it is possible to prevent the occurrence of defects due to the shaking of the sheet-shaped formed body K and the like. The judgment of the error.

Hereinafter, the defect inspection device 100 will be described in more detail. The conveying unit 11 shown in Fig. 1 and Fig. 2 is a device for conveying the sheet-shaped formed body K continuous in the Y direction in the Y direction. The conveyance unit 11 includes, for example, a feed roller and a take-up roller that convey the sheet-shaped formed body K in the Y direction, and can measure the conveyance distance by a rotary encoder or the like. The conveyance speed of the sheet-like molded body K conveyed by the conveyance part 11 in the Y direction is set to 2 m/min - 30 m / minute, for example.

The light-irradiating portion 12 includes a linear light source extending in a direction orthogonal to the Y direction, that is, an X-direction, and a position where the position of the light source is fixed to a fixed position of the delivery roller and the receiving roller of the conveying portion 11. The fixed member shown. The light source is formed by a sheet-shaped formed body K The reference is arranged such that the surface of the sheet-like formed body K can be irradiated with light on the same side as the imaging unit 13 or on the opposite side of the imaging unit 13. The light source is disposed such that the distance from the bright portion on the surface of the sheet-shaped formed body K is, for example, 200 mm. The light source is not particularly limited as long as it emits light that does not affect the composition and properties of the sheet-like formed body K, such as a metal halide lamp, a halogen linear lamp, or a fluorescent lamp.

The light irradiation unit 12 may include a long member disposed between the light source and the sheet-shaped formed body K. The elongate member is, for example, a member having a light-shielding plate-like base material containing a resin and forming a light-shielding region having a light-shielding property and extending in the X direction at a predetermined interval in the Y direction. When the light-irradiating portion 12 is provided with such a long member, a light-dark pattern in which the bright portion and the dark portion extending in the X direction are alternately repeated on the surface of the sheet-shaped formed body K can be formed, and the light-dark pattern can be used for inspection. Image data.

The imaging unit 13 includes a region sensor of a CCD (Charge Coupled Device) or a CMOS (Complementary Metal-Oxide Semiconductor). The imaging unit 13 is disposed so as to receive the surface of the sheet-shaped formed body K on the same side as the light source or the opposite side of the light source, and receives the transmitted light from the sheet-shaped formed body K with reference to the sheet-shaped molded body K. Or reflect light to produce two-dimensional image data. The imaging unit 13 can generate two-dimensional image data by one area sensor, or can generate two-dimensional image data based on data acquired by a plurality of area sensors arranged in the X direction. The imaging unit 13 is disposed such that the imaging range is the entire area of the X-direction of the sheet-shaped formed body K.

The length W in the Y direction of the imaging range shown in FIG. 1 is preferably at least twice or more the conveyance distance of the sheet-shaped formed body K conveyed during the shutter time of the imaging unit 13. In other words, the length W in the Y direction of the imaging range is preferably set so that the same portion of the sheet-shaped formed body K is subjected to the imaging operation twice or more. For example, when the shutter time of the imaging unit 13 is 1/30 second to 1 second, the length W in the Y direction of the imaging range is set to about 5 mm to 50 mm. In this way, the number of times of photographing the same portion of the sheet-shaped formed body K is increased, whereby the height can be increased. Check defects accurately.

The display unit 21 is, for example, a liquid crystal display, an EL (Electroluminescence) display, a plasma display or the like. The display unit 21 displays an inspection image indicated by the inspection image data on the display screen.

The inspection image data generation unit 141 includes a control arithmetic circuit such as a CPU (Central Processing Unit) or a DDR SDRAM (Double Data Rate Synchronous Dynamic Random Access Memory). Memory, and Flash ROM (Read Only Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory), HDD (Hard Disk Drive) ) and other non-volatile memory. The program data for functioning as the boundary extraction unit 1411, the re-extraction unit 1412, and the synthesis unit 1413 is stored in the non-volatile memory of the inspection image data generation unit 141, and the inspection image data is used in accordance with the program data. The generating unit 141 functions as the boundary extracting unit 1411, the re-extracting unit 1412, and the synthesizing unit 1413. Furthermore, the inspection image data generation unit 141 can also be realized by an image processing board such as an FPGA or a GPGPU or a hardware inside the imaging unit 13.

The boundary extraction unit 1411 extracts the boundary line portion from the two-dimensional image indicated by the two-dimensional image data generated by the imaging unit 13 by the previously known edge extraction method. The re-extraction unit 1412 connects the boundary line portions to form an apparent boundary line, and smoothes the apparent boundary line in such a manner that the sharp peaks appearing on the apparent boundary line are smoothed, from the two-dimensional image. The data is re-extracted to form pixels of the original boundary line obtained by smoothing. The synthesizing unit 1413 generates one-dimensional image data including one of the re-extracted pixels, and synthesizes a plurality of one-dimensional image data obtained from the plurality of two-dimensional image data in the same manner, thereby generating inspection image data.

Hereinafter, the re-extraction by the re-extraction unit 1412 will be described in detail. The re-extraction unit 1412 performs re-extraction of pixels from the two-dimensional image by the following processes (1) to (8).

(1) The pixel having the smallest X coordinate value among the extracted pixels extracted by the boundary extraction unit 1411 is set as the first pixel of interest. After the processing of (1), the processing of (2) is entered.

(2) It is assumed that the extracted pixels constituting the boundary line portion are from the pixel of interest to the +X direction to a specific number (for example, 1/40 to 1/ of all the pixels in the X direction of the two-dimensional image to be extracted) The extracted pixels in the range up to the number of 20) and the extracted pixels in the range from the -X direction to the specific number determine whether the following conditions are satisfied: <1> The Y coordinate value of all the extracted pixels in the range is The target pixel has a Y coordinate value or more, and at least one of the extracted pixels in the range of <2>+X direction and at least one of the extracted pixels in the range of the -X direction have greater than the attention. The Y coordinate value of the Y coordinate value of the pixel.

In the case where the conditions of both <1> and <2> are satisfied, the current attention pixel is set as the peak vertex pixel, and the process proceeds to (3).

In the case where the conditions of either or both of <1> and <2> are not satisfied, the X coordinate value is compared with the current pixel when there is an extracted pixel whose X coordinate value is larger than the current target pixel. The extracted pixel of the big 1 is changed to the next pixel of interest, and the processing of (2) is performed again.

In the case where the conditions of either or both of <1> and <2> are not satisfied, when there is no extracted pixel whose X coordinate value is larger than the current target pixel, the process proceeds to (5).

A specific example of the processing performed by the re-extracting unit 1412 will be described with reference to Fig. 9 . Fig. 9(a) shows a part of the two-dimensional image, and Fig. 9(b) shows a part of the extracted pixels extracted from the two-dimensional image by the boundary extracting unit 1411. The extracted pixel within the above range including the target pixel when the specific number is set to 3 and the pixel P _{1 of} FIG. 9(b) is set as the target pixel is shown in FIG. 9(c). Further, the extracted pixel within the above range including the target pixel when the specific number is set to 3 and the pixel P _{2 of} FIG. 9(b) is the target pixel is shown in FIG. 9(d). In FIG. 9 (c) of extracting the pixel shown, which comprises less than the Y coordinate is extracted as the pixel value of target pixel P Y coordinate values of _a pixel. Therefore, the pixel P _{1 is not} set as the peak vertex pixel, and the extracted pixel whose X coordinate value is larger than the pixel P _{1 is} changed to the next target pixel. The Y coordinate value of all the extracted pixels shown in FIG. 9(d) is larger than the Y coordinate value of the pixel P _{2 which is} the target pixel. Therefore, the pixel P ₂ is set as the peak vertex pixel, and the processing of (3) is entered.

(3) The extracted pixel in which the X coordinate value is smaller than the peak pixel of the peak and the Y coordinate value is larger than the peak pixel of the peak and the X coordinate value is the largest is the candidate pixel of the left end of the peak. Moreover, the extracted pixel in which the X coordinate value is larger than the peak pixel of the peak and the Y coordinate value is larger than the peak vertex pixel and the X coordinate value is the smallest is set as the peak right end candidate pixel. When the pixel P ₂ shown in FIG. 9(b) is set as the peak apex pixel, the pixel P ₃ becomes the peak left end candidate pixel, and the pixel P ₄ becomes the peak right end candidate pixel. After the processing of (3), the processing of (4) is entered.

(4) The following processes (4-1) and (4-2) are performed in sequence or in parallel.

(4-1) It is determined whether the Y coordinate value of the extracted pixel whose X coordinate value is smaller than the candidate pixel of the left end of the current peak is larger than the Y coordinate value of the candidate pixel of the left end of the current peak.

When the condition is satisfied, the extracted pixel whose X coordinate value is smaller than the candidate peak of the left end of the current peak is changed to the candidate pixel of the left peak of the next peak, and the processing of (4-1) is performed again. When the condition is not satisfied, the candidate peak at the left end of the current peak is set to correspond to the left end pixel of the peak of the current peak vertex pixel (the most recently set peak apex pixel).

(4-2) It is determined whether the Y coordinate value of the extracted pixel whose X coordinate value is larger than the right end candidate pixel of the current peak is larger than the Y coordinate value of the candidate pixel of the right peak of the current peak.

When the condition is satisfied, the extracted pixel whose X coordinate value is larger than the right end candidate pixel of the current peak is changed to the next peak candidate pixel of the next peak, and the processing of (4-2) is performed again. When the condition is not satisfied, the right-end candidate pixel of the current peak is set to correspond to the peak right-end pixel of the current peak vertex pixel (the peak peak pixel set directly).

After the processing of (4-1) and (4-2), the pixel corresponding to the peak of the peak of the current peak and the pixel of the right end of the peak are set, and it is determined whether the pixel at the left end of the current peak or the pixel at the right end of the current peak has been set to The pixel or wave at the left end of the peak corresponding to the peak of the other peak The pixel at the right end of the peak.

When the left end pixel of the current peak or the right end pixel of the current peak has been set to correspond to the peak left end pixel or the right end pixel of the peak of the other peak peak pixel, the current peak peak pixel and the left end pixel corresponding to the current peak and the right end pixel of the current peak are cancelled. set up. When the left end pixel of the current peak or the right end pixel of the current peak is not set to correspond to the peak left end pixel or the right end pixel of the peak of the other peak peak pixel, the current peak peak pixel and the left peak pixel corresponding to the current peak and the right peak of the current peak are not cancelled. Set it to stay the same.

After the pixel of the current peak is removed, the pixel at the left end of the current peak, and the pixel at the right end of the current peak are set or maintained as they are, if there is an extracted pixel whose X coordinate value is larger than the current pixel, the X coordinate value is larger than the current pixel. The extracted pixel is changed to the next target pixel, and the processing of (2) is performed again. If there is no extracted pixel whose X coordinate value is larger than the current target pixel, the process proceeds to (5).

In the case of the example shown in FIG. 9(b), the pixel P _{2 is} set as the peak vertex pixel by the processing of the above (1) to (4), and the pixel P ₅ and the pixel P ₆ are respectively set to correspond to The peak at the left end of the peak and the pixel at the right end of the peak. Further, the pixel P _{7 is} set to another peak apex pixel, and the pixel P ₈ and the pixel P ₉ are respectively set to correspond to the peak left end pixel and the peak right end pixel.

(5) The pixel with the smallest X coordinate value in the peak of the peak is set as the first pixel of interest.

After the processing of (5), the processing of (6) is entered.

(6) It is determined whether the following condition is satisfied: the distance in the X direction corresponding to the peak of the peak of the pixel of interest and the pixel of the right end of the peak (the X coordinate value of the pixel at the right end of the peak - the X coordinate value of the pixel at the left end of the peak) is a specific number of pixels (for example) It is equal to or less than the number of all pixels in the X direction of the extracted two-dimensional image (1/20 to 1/5).

When the condition is satisfied, the process proceeds to (7).

In the case where the condition is not satisfied, there is a wave having an X coordinate value larger than the current pixel of interest. In the case of the peak vertex pixel, the peak vertex pixel whose X coordinate value is larger than the current target pixel and whose X coordinate value is the closest is changed to the next target pixel, and the processing of (6) is performed again.

When the condition is not satisfied, when there is no peak vertex pixel whose X coordinate value is larger than the current pixel of interest, the series of processing ends.

(7) It is determined whether the following condition is satisfied: the distance between the current pixel of interest and the Y-direction of the peak of the peak corresponding to the current pixel of interest (the Y coordinate value of the pixel at the left end of the peak - the Y coordinate value of the peak of the peak peak), or the current pixel of interest The shorter distance in the Y direction corresponding to the right end pixel of the peak corresponding to the current pixel (the Y coordinate value of the pixel at the right end of the peak - the Y coordinate value of the peak pixel of the peak) is in the X direction of the pixel at the left end of the peak and the pixel at the right end of the peak. The distance (the X coordinate value of the pixel at the right end of the peak - the X coordinate value of the pixel at the left end of the peak) is a specific multiple (for example, 1/2 times to 2 times).

When the condition is satisfied, the process proceeds to (8).

When the condition is not satisfied, when there is a peak vertex pixel whose X coordinate value is larger than the current target pixel, the peak value of the peak with the X coordinate value larger than the current target pixel and the X coordinate value being the closest is changed to the next target pixel, and then performed again. (6) Processing.

When the condition is not satisfied, when there is no peak vertex pixel whose X coordinate value is larger than the current pixel of interest, the series of processing ends.

In the case of the example shown in FIG. 9(b), the peak vertex pixel P ₂ and the peak left end pixel P ₅ and the peak right end pixel P ₆ satisfy the condition of (6) and the condition of (7). The peak vertex pixel P ₇ , and the peak left end pixel P ₈ and the peak right end pixel P ₉ corresponding thereto are the distance in the Y direction from the peak vertex pixel P ₇ and the peak left end pixel P ₈ , and the peak vertex pixel P ₇ and the peak right end the distance in the X direction ₉ of the left peak to the peak pixel P ₈ on the right end of the pixel from the pixel P P ₉ of the Y direction is 1/5 instead of a specific value or more (e.g., 1/2 - 2) times, therefore, is not Meet the conditions of (7).

Thus, according to the conditions of (6) and the conditions of (7), only the sharp peaks considered to be caused by the defects are selected, and the peaks considered to be not caused by the defects are not selected.

(8) Calculate an expression indicating that a line segment corresponding to the peak of the peak of the current pixel and the pixel of the right end of the peak is connected, and extract the pixel on the line as the re-extracted pixel. However, the line segment passes through two pixels M(x _p , y _q ), N(x _p , y _q +1) which are located between the pixel at the left end of the peak and the pixel at the right end of the peak in the X direction and are adjacent in the Y direction. In the inter-time, the pixel N(x _p , y _q +1) is taken as the re-extracted pixel. Regarding the extracted pixel having the same X coordinate value as the re-extracted pixel and having the Y coordinate value different from the re-extracted pixel among the extracted pixels extracted by the boundary extracting portion 1411, as the pixels constituting the boundary line portion, the re-extracted pixel replacement is performed. Extract pixels. In this way, the boundary portion obtained by replacing one of the extracted pixels with the re-extracted pixel forms an original boundary line after the influence of the defect is excluded. As shown in FIG. 9(e), the extracted pixel after replacement is a dark portion corresponding to the boundary line portion which is distorted due to the concave defect included in the original two-dimensional image data, and the concave portion can be represented by the dark portion. The location.

The re-extraction unit 1412 performs re-extraction by the above processes (1) to (8), but the method of re-extraction is not limited thereto. For example, as another method of re-extracting, a curve expressed by a function may be fitted to a boundary line portion extracted by the boundary extracting unit 1411 to obtain a fitting curve (function curve), and then the fitting curve may be obtained. The resulting smoothing curve is smoothed, and finally, the pixels in the two-dimensional image fitted to the smoothing curve are set as extracted pixels. As a function for fitting, an n-th order function, a Gaussian function, a Lorentz function, a Voigt function, a combination of these functions, and the like can be cited. As the evaluation method of the fitting used in the fitting, for example, the least square method can be used.

1‧‧‧Image generating device

11‧‧‧Transportation Department

12‧‧‧Lighting Department

13‧‧‧Photography Department

14‧‧‧Information processing device

21‧‧‧Display Department

100‧‧‧ Defect inspection device

141‧‧‧Image data generation department for inspection

1411‧‧The Border Extraction Department

1412‧‧‧Re-extraction department

1413‧‧‧Combination Department

Claims (3)

An image generating device that generates image data for inspecting a defect of a sheet-shaped formed body, and includes: a conveying portion that conveys the sheet-shaped formed body along a longitudinal direction of the sheet-shaped formed body; and a light-irradiating portion A light source that linearly extends in the width direction of the sheet-like formed body, and the sheet-shaped molded body is irradiated with light by the light source, and the image capturing unit performs an image capturing operation on the sheet-shaped formed body during conveyance to generate a representation a two-dimensional image data of the dimensional image, and the plurality of imaging operations performed on the sheet-shaped formed body corresponding to the position of the bright portion of the light source and the dark portion having a lower brightness than the bright portion in the two-dimensional image; and inspection The image data generating unit generates inspection image data from a plurality of pieces of two-dimensional image data generated by the imaging unit, and includes a boundary extraction unit that extracts and displays the two-dimensional image data. a boundary line portion between the bright portion and the dark portion in each two-dimensional image; and a re-extraction portion that connects the boundary portion to form an apparent boundary line, and the sharp line appears on the apparent boundary line Wave peak elimination In the manner of smoothing the apparent boundary line, extracting pixels constituting the original boundary line obtained by smoothing from the two-dimensional image data; and synthesizing the portion including the extraction by the re-extraction unit One-dimensional image data of the pixel, and a plurality of one-dimensional image data obtained from the plurality of two-dimensional image data in the same manner are synthesized to generate inspection image data. A defect inspection device comprising: the image generation device of claim 1; and a display portion displayed by the inspection image data generated by the inspection image data generation portion of the image generation device image. A defect inspection method for inspecting a defect of a sheet-shaped formed body, comprising: a photographing step of irradiating the sheet-shaped formed body with a light source extending linearly in a width direction of the sheet-shaped formed body In the state in which the sheet-like formed body is conveyed in the longitudinal direction of the sheet-like formed body, the sheet-shaped formed body is imaged to generate two-dimensional image data representing a two-dimensional image, and The two-dimensional image includes a plurality of imaging operations on the sheet-shaped formed body corresponding to a bright portion of the light source and a dark portion having a lower brightness than the bright portion; and an interface extraction step of extracting the image forming step a boundary line between the bright portion and the dark portion in each two-dimensional image represented by each two-dimensional image data; and a re-extraction step of connecting the boundary portions to form an apparent boundary line, The way in which the sharp peaks appearing on the boundary line disappears, smoothes the boundary line of the apparent view, and extracts pixels from the two-dimensional image data that constitute the original boundary line obtained by smoothing; a step of generating a one-dimensional image data including one of the pixels extracted in the above-mentioned re-extraction step, and synthesizing a plurality of one-dimensional image data obtained from the plurality of two-dimensional image data in the same manner to generate an inspection map An image data; and a display step of displaying an image represented by the inspection image data generated in the above-described synthesis step.