JPH1194766A - Method and apparatus for inspecting texture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and quantitatively evaluate the texture of an object to be ispected such as a nonwoven fabric or the like without stopping a manufacturing apparatus, by taking the image of the reflected or transmitted light of the object to be inspected and a use reference surface, and extracting a plurality of characteristic quantities of the object from the taken image of the object. SOLUTION: The object 10 such as a nonwoven fabric or the like is irradiated with the light from a luminaire 20, and reflected light is taken in by a CCD camera 30. An image processing and operating apparatus 40 operates and extracts a plurality of characteristic quantities from the images of the object 10 and a use reference surface taken by the CCD camera 30. A characteristic quantity operating and processing part extracts the image data of a part other than the region taking the image of the use reference surface, that is, a texture index operating region and operates and extracts a plurality of characteristic quantities characterizing the texture of the object 10 to be inspected. The texture index operating and processing part connects a plurality of the characteristic quantities operated in the characteristic quantity operating and processing part to operate the texture index to display the same on a display apparatus.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a formation inspection method and apparatus for inspecting the formation of a thin sheet-like inspection object such as a nonwoven fabric, and more particularly, to an inspection method for a nonwoven fabric or the like without stopping a manufacturing apparatus. TECHNICAL FIELD The present invention relates to a formation inspection method and apparatus capable of easily and quantitatively evaluating a combination.

[0002]

2. Description of the Related Art In recent years, with the growth of sanitary products,
Demand for nonwoven fabrics and the like is growing significantly.

Conventionally, the quality of a nonwoven fabric or the like is generally evaluated based on formation (fiber distribution state), but most quality inspections rely on visual inspection by an inspector.

Further, in an apparatus aiming at automation of quality inspection of a non-woven fabric or the like, transmitted light or reflected light of the non-woven fabric to be inspected is imaged by an image pickup device such as a CCD, and a standard deviation of image luminance and a histogram of luminance are obtained. An index based on spatial frequency analysis is used as the formation index, which is a measure of the quality of nonwoven fabric.

[0005] Further, an apparatus for producing this kind of non-woven fabric or the like has two
It is operated without stopping for 4 hours, and when the formation which is one of the quality indices of the product in the manufacturing apparatus of such a nonwoven fabric is measured by an optical method, conventionally, the following 2
Two methods are known.

[0006] 1) Relative measurement method A method of measuring only a change in a subsequent value based on a measured value at the start of measurement and measuring only a change in the degree of formation.

2) Absolute measurement method A method of calibrating a measuring instrument using some reference and absolutely measuring the degree of formation based on the reference.

[0008]

However, a formation inspection apparatus using a standard deviation of luminance of an image or a histogram of luminance cannot capture spatial features of formation. For example, in a test object having substantially the same standard deviation of luminance and a histogram of luminance of a captured image, the degree of formation is evaluated to be completely the same even if the degree of formation is completely different from human eyes, and the degree of formation to be measured is evaluated. Is different from the degree of formation felt by humans.

[0009] In addition, a formation inspection device based on spatial frequency requires a dedicated filtering device and high-speed image processing.
There is a problem that the formation index does not match the human sense even with only the spatial frequency.

Further, in order to quantitatively measure the formation of a nonwoven fabric or the like, it is necessary to obtain a clear state of the fibers of the nonwoven fabric with high contrast. 1) Apply strong light or heat accompanying light to the material. Difficult to obtain a clear image, or 2) it is difficult to install equipment to block disturbance light, and it is difficult to obtain a clear fiber state due to disturbance light. There is.

As a method of inspecting for a defect in such a thin film, there is a method of placing a measuring object between deflection plates as disclosed in Japanese Patent Application Laid-Open No. 6-148059. 3) There is a problem that all the crimping points are detected as defects.

Further, in the above-mentioned apparatus for manufacturing nonwoven fabric and the like which is operated without stopping for 24 hours, 1) When the above-described relative measurement method is adopted, a change in the degree of formation can be known. The absolute value of the degree cannot be known. Therefore, after manufacturing, it is necessary to compare the product with the measured value.

2) When the absolute measurement method is adopted, it is affected by disturbances, aging of the light source and the camera, temperature change, and the like.
However, it is difficult to calibrate the measuring device during the manufacture of a product in a manufacturing device that operates for 24 hours. For this reason, after manufacturing, it is necessary to sample and measure the product.

3) There is also a method of arranging a sensor such as a light receiving element on a measurement surface and performing calibration using the output.
This sensor is also affected by changes over time and changes in temperature.

4) Further, when the above calibration is performed with the aperture or illumination of the camera, the dynamic range of the camera changes (the sensitivity changes). For this reason, there is a need for a calibration method that is not affected by fluctuations in the dynamic range of the camera.

Accordingly, an object of the present invention is to provide a formation inspection method and apparatus capable of easily and quantitatively evaluating the formation of an object to be inspected such as a nonwoven fabric without stopping a manufacturing apparatus.

[0017]

In order to achieve the above object, the invention of claim 1 provides a formation inspection method for inspecting the formation of an object to be inspected, the method comprising the steps of: Of the inspection target, performs a calibration process based on the captured image of the operation reference plane, extracts a plurality of feature amounts of the inspection target from the captured image of the inspection target, and extracts the plurality of feature amounts from the extracted plurality of feature amounts. It is characterized by inspecting the formation to be inspected.

According to a second aspect of the present invention, in the formation inspection apparatus for inspecting the formation of the inspection object, a light source for irradiating the inspection object and the operation reference surface, and a light source for irradiating the inspection object and the operation reference surface with the light source are provided. Imaging means for capturing an image of reflected light or transmitted light from a surface; calibration control means for calibrating and controlling the imaging means from the image of the operation reference plane taken by the imaging means; and the inspection taken by the imaging means A feature amount extracting unit that extracts a plurality of feature amounts from a target image; and an inspecting unit that inspects the formation of the inspection target from the plurality of feature amounts extracted by the feature amount extracting unit. I do.

According to a third aspect of the present invention, in the formation inspection method for inspecting the formation of the inspection object, the light from the light source is firstly transmitted.
A color filter for irradiating the inspection object with the deflection filter through the deflection filter and extracting a component of a specific color with the transmitted light of the inspection object, and a second deflection set to the same deflection angle as the first deflection filter. The image of the inspection target is captured from the light that has passed through the filter and the color filter and the second deflection filter, and the formation of the inspection target is inspected based on the captured image.

According to a fourth aspect of the present invention, in the formation inspection method for inspecting the formation of the inspection object, the light from the light source is transmitted to the first light source.
Irradiating the object to be inspected through the deflecting filter, and passing the transmitted light of the object to be inspected through a second deflecting filter set at a deflection angle orthogonal to the first deflecting filter. And picking up the image of the inspection target from the light that has passed through and inspecting the formation of the inspection target based on the captured image.

According to a fifth aspect of the present invention, in the fourth aspect of the present invention, the captured image is binarized, and the crimping point of the inspection object is detected by pattern matching of the binarized image. The formation of the object to be inspected is evaluated using the number of the crimped points as the formation index.

According to a sixth aspect of the present invention, in the formation inspection method for inspecting the formation of the inspection object, the light from the light source is firstly transmitted.
Irradiating the inspection target through a deflection filter, and extracting a component of a specific color from transmitted light of the inspection target,
The extracted light is separated into two lights, one of the separated lights is passed through a second deflection filter set at the same deflection angle as the first deflection filter, and the other light is separated. Is passed through a third deflection filter set at a deflection angle orthogonal to the first deflection filter, and the light passing through the second deflection filter is converted into a first beam of the inspection target.
And the second image of the inspection target is captured from the light that has passed through the third deflection filter, and the inspection target is determined based on an image obtained by subtracting the second image from the first image. Inspection of the formation is characterized.

According to a seventh aspect of the present invention, in the formation inspection apparatus for inspecting the formation of an inspection object, a first light source irradiating the inspection object and a first light source arranged between the light source and the inspection object are provided. , A color filter for extracting a component of a specific color from the transmitted light of the inspection target, and a second deflection filter set to the same deflection angle as the first deflection filter for transmitting the transmitted light of the inspection target. A deflection filter, imaging means for capturing the image of the inspection object from light passing through the color filter and the second deflection filter, and inspecting the formation of the inspection object based on the image captured by the imaging means. Inspection means.

According to an eighth aspect of the present invention, in the formation inspection apparatus for inspecting the formation of an inspection object, a first light source irradiating the inspection object and a first light source disposed between the light source and the inspection object are provided. , A second deflecting filter set at a deflection angle orthogonal to the first deflecting filter for transmitting the transmitted light of the object to be inspected, and the object to be inspected from light passing through the second deflecting filter. And an inspection unit that inspects the formation of the inspection target based on the image captured by the imaging unit.

According to a ninth aspect of the present invention, in accordance with the eighth aspect of the present invention, there is provided a binarizing means for binarizing an image picked up by the image pickup means, and a pattern matching of the image binarized by the binarizing means. It is characterized by comprising a crimping point detecting means for detecting the crimping point to be inspected, and an output means for outputting the number of crimping points detected by the crimping point detecting means as a formation index.

According to a tenth aspect of the present invention, in the formation inspection apparatus for inspecting the formation of an inspection object, a first light source irradiating the inspection object and a first light source disposed between the light source and the inspection object are provided. A deflection filter, a color filter that extracts a specific color component from the transmitted light of the inspection target, a beam splitter that separates the light extracted by the color filter into two lights, and a beam splitter that separates the light extracted by the beam splitter. A second deflection filter set to the same deflection angle as that of the first deflection filter that allows the light to pass through, and a deflection angle orthogonal to the first deflection filter that allows the other light split by the beam splitter to pass through A third deflection filter, a first imaging unit that captures a first image of the inspection target from light that has passed through the second deflection filter, and a third deflection filter. A second imaging unit that captures a second image of the inspection target from light that has passed through, and a second imaging unit that is captured by the second imaging unit from the first image that is captured by the first imaging unit. 2. Subtracting means for subtracting the two images, and inspection means for inspecting the formation of the inspection object based on the image obtained by the subtraction processing by the subtracting means.

[0027]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a schematic block diagram showing one embodiment of a formation inspection apparatus to which the formation inspection method and apparatus according to the present invention are applied.

In FIG. 1, the formation inspection apparatus irradiates an inspection object 10 such as a non-woven fabric wound in a roll form with an illumination 20 as a light source, and reflects a reflected light from the inspection object 10 with a CCD camera 30. Inspection object 1
Then, an image of the inspection target 10 captured by the CCD camera 30 is passed to the image processing operation device 40, thereby inspecting the formation of the inspection target 10.

Further, the inspection object 10 is not touched, and
An operation reference plane 50 is disposed at a position that partially enters the field of view of the CCD camera 30 (the field of view 30a of the CCD camera shown in FIG. 4), and the operation reference plane 50 enters the depth of focus of the CCD camera 30. Are arranged as follows.

The object 10 to be inspected such as a nonwoven fabric is several hundred meters.
/ Min speed.

The image processing operation device 40 includes the CCD camera 3
A plurality of feature amounts are calculated and extracted from the images of the inspection target 10 and the operation reference plane 50 taken at 0.

FIG. 2 is a block diagram showing the processing of the image processing arithmetic unit 40.

In FIG. 2, an image of the inspection object 10 captured by the CCD camera 30 is captured by an image capture processing unit 41 as image data on a memory (not shown) of the image processing arithmetic unit 40.

The image data fetched by the image fetching unit 41 into the memory of the image processing unit 40 is passed to a reference luminance calculation unit 42 and a feature amount calculation unit 44.

The reference luminance calculation processing section 42 converts the image data stored in the memory of the image processing
Only the region where the operation reference plane 50 is imaged, that is, only the operation surface average luminance calculation region 50a shown in FIG. 4 is extracted, and the average of the extracted operation surface average luminance calculation region 50a which images the operation reference surface 50 is extracted. Calculate the luminance (operational surface average luminance).

The aperture value calculation processing unit 43 refers to a reference brightness (set value) composed of the average brightness of the operation surface held in the image processing calculation device 40 or the average brightness set value input from the input device 47. The operation surface average brightness (reference brightness) calculated by the brightness calculation processing unit 42 is compared. If the absolute value of the difference between the set value and the reference brightness is equal to or larger than the measurement error δ, the CCD camera 30 An aperture control signal is output in response.

The aperture of the CCD camera 30 is controlled in accordance with the aperture control signal output from the aperture value processing unit 43.

In the comparison between the set value and the reference brightness in the aperture value calculation processing unit 43, if the absolute value of the difference between the set value and the reference brightness is smaller than the range of the measurement error δ, the feature value calculation processing unit 44 Calculation and extraction of the feature amount of the inspection target 10 are performed.

The feature amount calculation processing section 44 uses the image data fetched on the memory of the image processing calculation device 40 to obtain a portion other than the area where the operation reference plane 50 is imaged, that is, the feature amount calculation section shown in FIG. Area (formation index calculation area) 1
The image data 0a is extracted, and a plurality of feature amounts characterizing the formation of the inspection target 10 are calculated and extracted from the extracted image data of the feature amount calculation region (formation index calculation region) 10a.

Here, the plurality of feature amounts characterizing the formation of the inspection object 10 include: 1) uniformity of an image (standard deviation of luminance data of an image) 2) lightness of an image (average luminance of luminance data of an image) 3) The coarse density of the image (sum of the number of pixels within a certain range of the first derivative of the image data) and the like can be used.

The formation index calculation processing section 45 linearly combines the plurality of feature amounts calculated by the feature amount calculation processing section 44 to calculate the formation index of the inspection target 10. In the formation index calculation processing by the formation index calculation processing unit 45, the weight (coupling coefficient) at the time of combination can be configured to be designated from the input device 47.

The formation index calculated by the formation index calculation processing section 46 is passed to a display device 47, where it is displayed.

FIG. 3 is a flowchart showing the processing of the image processing arithmetic unit 40.

In FIG. 3, first, the image capturing processing unit 41 captures an image of the inspection target 10 captured by the CCD camera 30 as image data on a memory (not shown) of the image processing arithmetic unit 40 (step 101). ).

Next, the reference luminance calculation processing section 42 calculates the reference luminance, that is, the average luminance (operation plane average luminance) of the operation plane average luminance calculation area 50a shown in FIG. 4 (step 102).

Then, the reference luminance and the set value calculated in step 102, that is, the operation surface average luminance or the input device 4 held inside the image processing operation device 40
A comparison is made with the set value consisting of the average brightness set value input from step 7 (step 103).

If it is determined that the reference luminance is not equal to the set value, that is, if the absolute value of the difference between the set value and the reference luminance is equal to or larger than the measurement error δ (NO in step 103), In the aperture value calculation processing unit 43, an aperture control value for the CCD camera 30 is calculated (step 10).
4) Return to step 101.

If it is determined in step 103 that the reference luminance is equal to the set value, that is, if the absolute value of the difference between the set value and the reference luminance is smaller than the range of the measurement error δ (step 103). YES), the feature value calculation processing unit 44 performs feature value calculation for calculating a plurality of feature values of the inspection target 10 (step 105).

The plurality of feature values calculated in step 105 are passed to the formation index calculation processing unit 45, where the plurality of feature values are linearly combined to calculate the formation index of the inspection object 10. That is, formation index calculation is performed (step 106).

The formation index calculated in step 106 is passed to the display device 47, where the formation index is displayed (step 107), and the process is terminated.

Note that, in the processing shown in FIG.
Calibration processing for controlling the aperture of D camera 30 and inspection object 1
Although the operation example in which the measurement processing for calculating the formation index of 0 is performed at the same time has been described, the following operation is also possible.

1) The calibration process is executed every time the inspection apparatus is started. 2) The calibration process is performed each time before the formation index measurement process is performed. 3) The calibration process is performed at regular intervals regardless of the formation index measurement process.

In the above configuration, the operation reference plane 5
Although 0 is arranged at the upper end of the screen of the CCD camera 30, the following arrangement is also possible.

1) The operation reference plane 50 is arranged at the lower end of the screen of the CCD camera 30. 2) The operation reference plane 50 is arranged at the right or left end of the screen of the CCD camera 30. 3) The operation reference plane 50 is divided and arranged at four corners of the screen of the CCD camera 30.

In the above configuration, the CCD camera 3
Although the case where an area CCD camera is used is shown as 0, the same configuration can be made by using a line CCD camera. Further, in the above configuration, the reflected light from the inspection target is used. However, the same configuration can be made by using the transmitted light.

FIG. 5 is a schematic configuration diagram showing another embodiment of a formation inspection apparatus to which the formation inspection method and apparatus according to the present invention are applied.

In FIG. 5, the parts performing the same functions as those of the formation inspection apparatus shown in FIG. 1 are denoted by the same reference numerals for convenience of explanation.

In the formation inspection apparatus shown in FIG.
Is configured using a linear CCD camera 300, whereas the CCD camera 30 shown in FIG. 1 is an area camera, and the operation reference surface 50 shown in FIG. On the other hand, in the configuration shown in FIG.
Are arranged along the transport direction of
It differs from the configuration shown in FIG. 1 in that a rotary encoder 60 is provided on a roller around which 0 is wound.

In the configuration shown in FIG. 5,
The image capturing process 41 shown in FIG. 2 is performed in synchronization with the output pulse of the rotary encoder 60,
In the processing of the image processing arithmetic unit 500, the calculation and evaluation method of the formation index is the same as the configuration shown in FIG. 1 except that the image data is only one-dimensional.

That is, in FIG. 5, the formation inspection apparatus irradiates an inspection object 10 such as a non-woven fabric wound in a roll form with a light source 20 as a light source, and reflects a reflected light from the inspection object 10 into a linear CCD. The inspection object 10 is captured by the camera 300 and the image of the inspection object 10 captured by the linear CCD camera 300 is passed to the image processing arithmetic unit 400 to inspect the formation of the inspection object 10.

Further, without touching the inspection object 10,
An operation reference plane 500 is arranged at a position that falls within a part of the field of view synthesized by the linear CCD camera 300 (the field of view 300a synthesized from the linear CCD in FIG. 6). It is arranged so as to be inside the depth of focus.

The object 10 to be inspected such as a nonwoven fabric is several hundred meters.
/ Min speed.

The image processing operation device 400 is a linear CCD
A plurality of feature amounts are calculated and extracted from the images of the inspection target 10 and the operation reference plane 500 captured by the camera 300.

Further, the image processing operation device 400 synchronizes with the output pulse of the rotary encoder
The image data output from the D camera 300 is stored.

In this case, the image processing operation device 400 starts to accumulate the image data output from the linear CCD camera 300 at the image data accumulation start point shown in FIG.
At the image data accumulation end point shown in FIG.
The accumulation of one line of image data output from 00 is ended.

That is, in this configuration, the image processing unit 400 converts the one-dimensional image output from the linear CCD camera 300 in synchronization with the output pulse of the rotary encoder 60 and the image data of the image processing unit 400 (not shown). It accumulates in a contiguous area of memory. Thereby, the same output as the area CCD is obtained from the linear CCD in a pseudo manner. By obtaining the same output as that of the area CCD in a pseudo manner, the same image data processing as the configuration shown in FIG. 1 can be performed.

FIG. 7 is a schematic configuration diagram showing still another embodiment of a formation inspection apparatus to which the formation inspection method and apparatus according to the present invention are applied.

In FIG. 7, the parts having the same functions as those of the formation inspection apparatus shown in FIG. 1 are denoted by the same reference numerals for convenience of explanation.

In the formation inspection apparatus shown in FIG.
Is different from the configuration shown in FIG. 1 in that the operation reference surface 50 shown in FIG. 1 is divided into a black operation reference surface 51 and a white operation reference surface 52.

That is, in FIG. 7, this formation inspection apparatus irradiates an inspection object 10 such as a non-woven fabric wound in a roll shape with a light source 20 as a light source, and reflects a reflected light from the inspection object 10 with a CCD camera. The inspection object 10 is imaged by taking it in at 30, and the formation of the inspection object 10 is inspected by passing the image of the inspection object 10 imaged by the CCD camera 30 to the image processing arithmetic unit 401.

Further, without touching the inspection object 10,
The field of view of the CCD camera 30 (CCD camera field of view 3 in FIG. 10)
0a), operation reference surfaces 51 and 52 are arranged at positions that enter a part of the operation reference surfaces 51 and 52.
It is arranged so as to enter inside the depth of focus of the CD camera 30.

The object 10 to be inspected such as a nonwoven fabric is several hundred meters.
/ Min speed.

The image processing arithmetic unit 401 includes the inspection object 10 and the operation reference surfaces 51, 5 taken by the CCD camera 30.
A plurality of feature values are arithmetically extracted from the two images.

FIG. 8 is a block diagram showing the processing of the image processing arithmetic unit 401.

In FIG. 8, the parts having the same functions as those in the block diagram shown in FIG. 2 are denoted by the same reference numerals for convenience of explanation.

In FIG. 8, an image of the inspection object 10 picked up by the CCD camera 30 is fetched as image data into a memory (not shown) of the image processing arithmetic unit 401 by the image fetch processing unit 41.

The image data fetched by the image fetch processing section 41 into the memory of the image processing operation device 401 is passed to the reference luminance calculation processing section 48 and the normalization processing section 49.

The reference luminance calculation processing section 48 converts the image data fetched into the memory of the image processing
The area where the operation reference plane 52 is imaged, that is, FIG.
Only the operation surface average luminance calculation area 52a shown in (1) is extracted, and the average luminance (operation surface average luminance) of the operation surface average luminance calculation area 52a capturing the extracted operation reference plane 52 is calculated.

The aperture value calculation processing section 43 refers to the reference brightness (set value) composed of the average brightness of the operation surface held in the image processing calculation device 40 or the average brightness set value input from the input device 47. The operation surface average luminance (reference luminance) calculated by the luminance calculation processing section 48 is compared with the CCD camera 30 if the absolute value of the difference between the set value and the reference luminance is equal to or larger than the range of the measurement error δ. An aperture control signal is output in response.

The aperture of the CCD camera 30 is controlled in accordance with the aperture control signal output from the aperture value calculation processing section 43.

In comparison between the set value and the reference luminance in the aperture value calculation processing section 43, if the absolute value of the difference between the set value and the reference luminance is smaller than the range of the measurement error δ, the processing of the normalization processing section 49 Is performed.

The normalization processing section 49 normalizes the image data of the feature amount calculation area (formation index calculation area) 10a shown in FIG. 10 using the difference between the average luminances of the operation reference plane 51 and the operation reference plane 52. I do.

In this configuration, since the image data has 256 gradations, the average luminance of the operation reference surface 51 is normalized to be 0, and the average luminance of the operation reference surface 52 is to be 255.

That is, the image data of the feature amount calculation area (formation index calculation area) 10a shown in FIG.
y), if the normalized image data is f ′ (x, y), the average luminance of the operation reference plane 51 is V1, and the average luminance of the operation reference plane 52 is V2, FIG. The image data of the indicated feature amount calculation area (formation index calculation area) 10a is normalized.

F '(x, y) = (255 / (V2-V
1)) × f (x, y) −255 / (V2−V1)

In the above equation, the linear normalization is performed with the minimum being 0 and the maximum being 255. However, the minimum and maximum values and the normalization method (linear or non-linear) take into account the characteristics of the CCD camera 30. To decide.

The characteristic amount calculation processing section 44 uses the image data fetched in the memory of the image processing calculation device 40 to a portion other than the area where the operation reference surfaces 51 and 52 are imaged, that is, the characteristic shown in FIG. The image data of the quantity calculation area (formation index calculation area) 10a is extracted, and a plurality of pieces of data that characterize the formation of the inspection target 10 are obtained from normalized data of the extracted image data of the feature quantity calculation area (formation index calculation area) 10a. The feature amount of is calculated and extracted.

Here, a plurality of feature amounts characterizing the formation of the inspection object 10 include: 1) uniformity of an image (standard deviation of luminance data of an image) 2) lightness of an image (average luminance of luminance data of an image) 3) The coarse density of the image (sum of the number of pixels within a certain range of the first derivative of the image data) and the like can be used.

The formation index calculation processing section 45 linearly combines the plurality of feature values calculated by the feature value calculation processing section 44 and calculates the formation index of the inspection target 10. In the formation index calculation processing by the formation index calculation processing unit 45, the weight (coupling coefficient) at the time of combination can be configured to be designated from the input device 47.

The formation index calculated by the formation index calculation processing section 46 is passed to the display device 47, where it is displayed.

FIG. 9 is a flowchart showing the processing of the image processing arithmetic unit 401.

Referring to FIG. 9, first, the image capture processing unit 41 captures an image of the inspection target 10 captured by the CCD camera 30 into image data on a memory (not shown) of the image processing arithmetic unit 401 (step 201). ).

Next, the reference luminance calculation processing section 48 calculates the reference luminance, that is, the average luminance (operation plane average luminance) of the operation plane average luminance calculation area 52a shown in FIG. 10 (step 202).

Then, the reference luminance and the set value calculated in step 202, that is, the image processing arithmetic unit 401
Is compared with the operation surface average luminance stored in the storage unit or the set value including the average luminance set value input from the input device 47 (step 203).

If it is determined that the reference luminance is not equal to the set value, that is, if the absolute value of the difference between the set value and the reference luminance is greater than or equal to the range of the measurement error δ (NO in step 203), In the aperture value calculation processing section 43, an aperture control value for the CCD camera 30 is calculated (step 20).
4) Return to step 201.

If it is determined in step 203 that the reference luminance is equal to the set value, that is, if the absolute value of the difference between the set value and the reference luminance is smaller than the range of the measurement error δ (step 203). YES), the feature amount calculation area (formation index calculation area) 10 shown in FIG.
A normalization process for normalizing the image data a is performed (step 205).

Next, a feature value calculation for calculating a plurality of feature values of the inspection object 10 using the image data subjected to the normalization process by the feature value calculation processing section 44 is performed (step 2).
06).

The plurality of feature values calculated in step 206 are passed to the formation index calculation processing unit 45, where the plurality of feature values are linearly combined to calculate the formation index of the inspection object 10. That is, formation index calculation is performed (step 207).

The formation index calculated in step 207 is passed to the display device 47, where the formation index is displayed (step 208), and the process is terminated.

Note that, in the processing shown in FIG.
Calibration processing for controlling the aperture of D camera 30 and inspection object 1
Although the operation example in which the measurement processing for calculating the formation index of 0 is performed at the same time has been described, the following operation is also possible.

1) The calibration process is executed every time the inspection apparatus is started. 2) The calibration process is performed each time before the formation index measurement process is performed. 3) The calibration process is performed at regular intervals regardless of the formation index measurement process.

In the above configuration, the operation reference plane 5
Although 1, 52 are arranged at the upper end of the screen of the CCD camera 30, the following arrangements are also possible.

1) The operation reference surfaces 51 and 52 are arranged at the lower end of the screen of the CCD camera 30. 2) The operation reference surfaces 51 and 52 are arranged at the right end or the left end of the screen of the CCD camera 30. 3) Divide the operation reference surfaces 51 and 52, and
0 is divided and arranged on the screen.

FIG. 11 is a schematic configuration diagram showing another embodiment of a formation inspection apparatus to which the formation inspection method and apparatus according to the present invention are applied.

In the configuration shown in FIG. 11, the nonwoven fabric 330 to be inspected is irradiated by the transmitted light source 310 through the deflection filter 320 as the first deflection filter.
The light transmitted through the non-woven fabric 330 passes through a color filter 340 and a deflection filter 350 as a second deflection filter, and the light is transmitted through the non-woven fabric 330.
The image is taken into the CD camera 360, and a transmission image of the nonwoven fabric 330 is captured by the CCD camera 360.

The image of the nonwoven fabric 330 captured by the CCD camera 360 is taken into the image processing device 370, and the image processing device 370 performs a predetermined process for inspecting the formation of the nonwoven fabric 330.

Here, the deflection filter 350 as the second deflection filter is disposed so as to have the same deflection angle as the deflection filter 320 as the first deflection filter.

As the color filter 340, a red color filter that selectively transmits red light is used.

In the configuration shown in FIG. 11, the arrangement relationship between the deflection filter 350 and the color filter 340 may be reversed.

By the way, according to such a configuration, the light incident on the non-woven fabric 330 to be inspected is
20, the polarization directions are aligned.

When the light having the same polarization direction collides with the fiber of the non-woven fabric 330, the light is scattered into light in various deflection directions.

Here, in the thin portion of the fiber of the nonwoven fabric 330, the scattering effect is small, and the component in which the deflection direction changes is small.

In the thick part of the nonwoven fabric 330, a component whose deflection direction changes due to the scattering effect is generated.

When the light that has passed through the nonwoven fabric 330 passes through the deflection filter 350, the light that has passed through the thin portions of the fibers of the nonwoven fabric 330 has the following effects: 1) little attenuation due to fiber absorption 2) scattering Due to the fact that the component of the light whose deflection direction has changed is small, the attenuation of the light is small.

Conversely, light that has passed through the thick portion of the fiber of the nonwoven fabric 330 has the following two effects: 1) the attenuation is large due to the absorption of the fiber; and 2) the component of the light whose deflection direction is changed due to the scattering is small. Increase in attenuation.

Further, the disturbance light has components in all deflection directions, but the disturbance light passes through the deflection filter 320,
Further, while the light is reflected by the nonwoven fabric 330, a component different from the deflection angle of the deflection filter 320 is dropped by the deflection filter 320, so that the influence of disturbance light can be suppressed.

With such an operation, the CCD camera 36
At 0, a transmitted light image with improved contrast can be obtained.

Next, the operation will be described.

In general, in the nonwoven fabric 330, the light that has passed through the deflection filter 320 is largely scattered at the compression point of the nonwoven fabric 330 (the press-bonded portion of the fiber). Therefore, when the color filter 340 is not used, the compression point is imaged by the CCD camera 360 as a black point.

This phenomenon is considered to be because light emitted from the transmitted light source 310 contains components of many wavelengths and is easily affected by scattering. Therefore, a red color filter 340 is inserted into the optical path to the CCD camera 360, and the red color filter 340 is configured to transmit only a long wavelength component having a small influence of scattering. It is possible to minimize it.

Instead of the color filter, a red transmitted light source or only the R output of a 3CCD camera can be used.

According to such a configuration, it is possible to suppress the influence of disturbance light and obtain an image with high contrast.

The processing for inspecting the formation of the nonwoven fabric 330 in the image processing device 370 includes, for example, the image processing operation device 40 described with reference to FIGS.
The same processing as 400 and 401 can be adopted.

In the embodiment of the present invention shown in FIG. 11, the following effects can be expected.

1) The deflection filter 320 as the first deflection filter and the deflection filter 35 as the second deflection filter
By setting the deflection angle to 0 to be the same, it is possible to obtain a clear transmitted light image that suppresses the influence of disturbance light even with a weak transmitted light source.

2) By using the red color filter 34, it is possible to obtain an image with light having a wavelength that is hardly scattered at the compression point of the non-woven fabric 330.
It is possible to obtain an image that suppresses the effect of 30 crimp points,
This enables highly accurate formation quality inspection.

FIG. 12 is a schematic configuration diagram showing still another embodiment of a formation inspection apparatus to which the formation inspection method and apparatus according to the present invention are applied.

The structure shown in FIG. 12 is different from the structure shown in FIG. 11 in that the light transmitted through the color filter 340 is split into two lights by a beam splitter 830, and one of the lights passes through a deflection filter 350 which is a second deflection filter. Then, a transmission image (first image) of the nonwoven fabric 330 is captured by the CCD camera 360, and the other light is transmitted through the reflecting mirror 381 and the deflection filter 351 which is the third deflection filter. The image is captured by the CCD camera 361, and a transmission image (second image) of the nonwoven fabric 330 is captured by the CCD camera 361.

Here, the deflection filter 350 as the second deflection filter is arranged so as to have the same deflection angle as the deflection filter 320 as the first deflection filter, as in FIG. The deflection filter 351 which is the first deflection filter is the deflection filter 32 which is the first deflection filter.
They are arranged to have a deflection angle orthogonal to 0.

In such a configuration, the CCD camera 3
The first image picked up by 60 is mainly an image formed by transmitted light using the transmitted light source 310 as in the configuration shown in FIG.

However, the second image picked up by the CCD camera 361 is because the deflection angles of the deflection filter 320 and the deflection filter 351 are orthogonal to each other. 1) Disturbance light reflected on the surface of the nonwoven fabric to be inspected 2) is a composite image of the transmitted light image due to the change in the deflection angle due to the scattering of the light from the transmitted light source by the fibers of the nonwoven fabric.

Here, the image of the transmitted light due to the change in the deflection angle due to the scattering of the light from the transmitted light source by the fibers of the non-woven fabric in the above 2) is such that the thick portions of the fibers are bright and the thin portions of the fibers are dark.

Therefore, in this embodiment, CC
After the D camera 360 and the CCD camera 361, C
CC from the first image taken by CD camera 360
A subtraction circuit 390 for subtracting the second image captured by the D camera 361 is provided.

The image obtained by the subtraction by the subtraction circuit 390 is different from that of the CCD camera 360 in which the thin portion of the nonwoven fabric 330 to be inspected is bright and the thick portion is dark, and the image of the CCD camera 361 in which the thin portion is dark and the thick portion is bright. Since the image is drawn, the contrast between the bright part and the dark part can be greatly improved.

In the subtraction circuit 390, when the subtraction result becomes negative, zero is output.

As a result, it is possible to suppress the influence of disturbance light and obtain an image with a high contrast.

As described above, according to the embodiment shown in FIG. 12, the following effects can be expected.

1) By using the red thread color filter 340, it is possible to obtain an image with light having a wavelength that is hardly scattered at the crimping point.
It is possible to obtain an image in which the influence of the crimping point of 0 is suppressed.

2) The image obtained by the CCD camera 360 mainly includes a large amount of transmitted light, and the image obtained by the CCD camera 361 mainly includes a large amount of reflected light due to disturbance light. From the CCD camera 361
By subtracting the image, the influence of disturbance light can be reduced from the image, and a very high-contrast image reflecting the state of the fibers of the nonwoven fabric 330 to be inspected can be obtained. Inspection of quality becomes possible.

FIG. 13 is a schematic configuration diagram showing still another embodiment of a formation inspection apparatus to which the formation inspection method and apparatus according to the present invention are applied.

The configuration shown in FIG. 13 is different from the configuration shown in FIG. 11 in that the deflection angle is orthogonal to the deflection filter 320 as the first deflection filter instead of the deflection filter 350 as the second deflection filter shown in FIG. The configuration shown in FIG. 11 differs from the configuration shown in FIG. The other configuration is the same as the configuration shown in FIG.

According to the configuration shown in FIG. 13, in the image of the nonwoven fabric 330 taken by the CCD camera 360, the pressure-bonded point of the nonwoven fabric 330 looks white and clear.

Here, this crimping point is determined by the nonwoven fabric 3 to be inspected.
When the condition of 30 formations is good, the image looks good with respect to the background.

Conversely, when the condition of the nonwoven fabric 330 to be inspected is poor, the contrast with the background is low.
It doesn't look sharp.

Therefore, the formation of the nonwoven fabric 330 to be inspected can be evaluated by counting the number of the clear pressure bonding points.

FIG. 14 is a flowchart showing a process of evaluating the formation in the image processing device 370 in the embodiment shown in FIG.

In FIG. 14, first, the CCD camera 36
The captured image according to 0 is captured as image data (step 401).

Next, the captured image data is subjected to smoothing filter processing to remove noise (step 40).
2). Then, the image data from which the noise has been removed is
The image is divided into regions of × m pixels, an average value of the luminance of each of the divided regions is obtained, and binarization is performed using the average value of the luminance as a threshold (step 403).

Next, in order to search for a compression point from the binarized image, pattern matching is performed using a reference pattern as shown in FIG. 15 (step 404).

As a result of this pattern matching, the number of points having a degree of conformity of 75% or more is obtained, and this is detected as the number of crimping points (step 405).

Then, the number of crimping points detected in step 405 is output as formation index (step 406),
This processing ends.

According to such a configuration, a clear image of the crimping point of the nonwoven fabric 330 to be inspected can be obtained clearly, so that formation can be easily measured.

According to the embodiment shown in FIG. 13, the following effects can be expected.

1) As a rule of thumb, when the nonwoven fabric is well-formed, the crimping point can be clearly detected, and when the nonwoven fabric is poorly formed, the crimping point becomes unclear. By arranging at right angles, it is possible to obtain a very clear image of the crimping points of the nonwoven fabric. Here, if the number of crimping points detected by pattern matching is counted, the formation of the nonwoven fabric can be obtained with a certain number. Can be evaluated indirectly.

2) The formation quality of the nonwoven fabric can be easily evaluated by using the crimping point which is an obstacle in measurement in reverse.

[0157]

As described above, according to the present invention,
The following effects can be obtained.

1) Since the aperture is adjusted based on the luminance from the camera image, measurement can be performed without being affected by the aging / temperature change of the light source, the CCD, and the like.

2) The operation reference plane can be arranged irrespective of the state of the manufacturing apparatus, and can be calibrated based on the operation reference plane while the manufacturing apparatus is operating.

3) Since calibration can be performed during the operation of the manufacturing apparatus, the absolute value of formation can be measured.

4) By setting the deflection angles of the first deflection filter and the second deflection filter to be the same, it is possible to obtain a clear transmitted light image in which the influence of disturbance light is suppressed even with a weak transmitted light source. It becomes possible.

5) By using a red color filter, it is possible to obtain an image with light having a wavelength that is hardly scattered at the compression point, so that it is possible to obtain an image in which the influence of the compression point is suppressed, and to obtain a high accuracy. Inspection of high formation quality becomes possible.

6) By using a red color filter, an image can be obtained with light having a wavelength that is hardly scattered at the compression point, and an image with less influence of the compression point can be obtained.

7) The image obtained by the first image pickup means mainly includes much influence of transmitted light, and the image obtained by the second image pickup means
Since the influence of the reflected light mainly due to disturbance light is largely included, the influence of disturbance light is reduced from the image by subtracting the image of the second imaging means from the image of the first imaging means, and the state of the fiber of the nonwoven fabric is reduced. , An image having a very high contrast can be obtained, thereby enabling highly accurate formation quality inspection.

8) As a rule of thumb, when the nonwoven fabric is well-formed, the crimping point can be clearly detected, and when the nonwoven fabric is poorly formed, the crimping point becomes unclear. Are arranged orthogonally, so that the image of the crimping points of the nonwoven fabric can be obtained very clearly, and if the number of crimping points detected by pattern matching is counted, the Can be evaluated indirectly.

9) The formation quality of the nonwoven fabric can be easily evaluated by using the crimping point which is an obstacle in measurement in reverse.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing one embodiment of a formation inspection apparatus configured by applying a formation inspection method and apparatus according to the present invention.

FIG. 2 is a block diagram for explaining processing of the image processing operation device shown in FIG. 1;

FIG. 3 is a flowchart for explaining processing of the image processing operation device shown in FIG. 1;

FIG. 4 is a view for explaining processing of the image processing operation device shown in FIG. 1;

FIG. 5 is a schematic configuration diagram showing another embodiment of the formation inspection apparatus configured by applying the formation inspection method and apparatus according to the present invention.

FIG. 6 is a view for explaining processing of the image processing operation device shown in FIG. 5;

FIG. 7 is a schematic configuration diagram showing still another embodiment of a formation inspection apparatus formed by applying the formation inspection method and apparatus according to the present invention.

FIG. 8 is a block diagram for explaining processing of the image processing operation device shown in FIG. 7;

FIG. 9 is a flowchart for explaining processing of the image processing operation device shown in FIG. 7;

FIG. 10 is a view for explaining processing of the image processing operation device shown in FIG. 7;

FIG. 11 is a schematic configuration diagram showing another embodiment of a formation inspection apparatus to which the formation inspection method and apparatus according to the present invention are applied.

FIG. 12 is a schematic configuration diagram showing still another embodiment of a formation inspection apparatus configured by applying the formation inspection method and apparatus according to the present invention.

FIG. 13 is a schematic configuration diagram showing still another embodiment of a formation inspection apparatus to which the formation inspection method and apparatus according to the present invention are applied.

FIG. 14 is a flowchart showing processing for evaluating the formation in the image processing apparatus shown in FIG. 13;

FIG. 15 is a view showing an example of a reference pattern used in pattern matching in the flowchart shown in FIG. 13;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Inspection object 20 Illumination 30 CCD camera 40, 400, 401 Image processing operation unit 41 Image capture processing unit 42, 48 Reference luminance operation processing unit 43 Aperture value operation processing unit 44 Feature amount operation processing unit 45 Formation index operation processing unit 46 Display device 47 Input device 49 Normalization processing unit 310 Transmitted light source 320 Deflection filter 330 Non-woven fabric 340 Color filter 350 Deflection filter 351 Deflection filter 360 CCD camera 361 CCD camera 370 Image processing device 380 Beam splitter 381 Reflecting mirror

Claims (10)

[Claims] 1. A formation inspection method for inspecting the formation of an inspection object, wherein an image of reflected light or transmitted light of the inspection object and the operation reference surface is captured, and a calibration process is performed based on the captured image of the operation reference surface. And extracting a plurality of feature amounts of the inspection target from the captured image of the inspection target, and inspecting the formation of the inspection target from the extracted plurality of feature amounts. 2. A formation inspection apparatus for inspecting the formation of an inspection object, comprising: a light source for irradiating the inspection object and the operation reference surface; and reflected light or transmission from the inspection object and the operation reference surface due to irradiation of the light source. Imaging means for capturing an image of light; calibration control means for calibrating and controlling the imaging means from the image of the operation reference plane captured by the imaging means; and a plurality of features from the image of the inspection object captured by the imaging means. A formation inspection apparatus, comprising: a feature amount extraction unit that extracts a quantity; and an inspection unit that inspects the formation of the inspection target from a plurality of feature amounts extracted by the feature amount extraction unit. 3. A formation inspection method for inspecting the formation of an inspection object, wherein the inspection object is irradiated with light from a light source via a first deflecting filter, and transmitted light of the inspection object has a specific color. The light is passed through a color filter for extracting components and a second deflection filter set at the same deflection angle as the first deflection filter, and from the light passed through the color filter and the second deflection filter, A formation inspection method, comprising taking an image and inspecting the formation of the inspection object based on the taken image. 4. A formation inspection method for inspecting the formation of an inspection object, wherein the inspection object is irradiated with light from a light source via a first deflection filter, and transmitted light of the inspection object is transmitted to the first object. The light passes through a second deflection filter set at a deflection angle orthogonal to the deflection filter, captures an image of the inspection target from light passing through the second deflection filter, and performs inspection of the inspection target based on the captured image. A formation inspection method characterized by inspecting formation. 5. The image picked-up image is binarized, the crimping point of the inspection target is detected by pattern matching of the binarized image, and the number of the detected crimping points is used as a formation index to determine the ground of the inspection target. 5. The formation inspection method according to claim 4, wherein the combination is evaluated. 6. A formation inspection method for inspecting the formation of an inspection object, wherein the inspection object is irradiated with light from a light source via a first deflection filter, and a specific color of light is transmitted from the inspection object. A component is extracted, the extracted light is separated into two lights, and one of the separated lights is passed through a second deflection filter set at the same deflection angle as the first deflection filter, The other separated light passes through a third deflection filter set at a deflection angle orthogonal to the first deflection filter, and the first image of the inspection object is converted from the light passing through the second deflection filter. A second image of the inspection target is captured from the light that has passed through the third deflection filter, and the formation of the inspection target is determined based on an image obtained by subtracting the second image from the first image. Inspecting Formation testing method which is characterized. 7. A formation inspection apparatus for inspecting the formation of an inspection object, a light source for irradiating the inspection object, a first deflection filter disposed between the light source and the inspection object, A color filter for extracting a component of a specific color from the transmitted light of the object, a second deflection filter set at the same deflection angle as the first deflection filter for transmitting the transmitted light of the inspection object, Imaging means for capturing the image of the inspection target from light having passed through the filter and the second deflection filter; and inspection means for inspecting the formation of the inspection target based on the image captured by the imaging means. A formation inspection device characterized by the above-mentioned. 8. A formation inspection apparatus for inspecting formation of an inspection object, a light source for irradiating the inspection object, a first deflection filter arranged between the light source and the inspection object, and the inspection A second deflecting filter set at a deflection angle orthogonal to the first deflecting filter that allows the transmitted light of the object to pass therethrough, and an imaging unit that captures the image of the inspection target from the light that has passed through the second deflecting filter And an inspection means for inspecting the formation of the inspection object based on the image picked up by the image pickup means. 9. A binarizing unit for binarizing an image taken by the imaging unit, and a crimping point detection for detecting the crimping point of the inspection object by pattern matching of the image binarized by the binarizing unit. 9. The formation inspection device according to claim 8, further comprising: means, and output means for outputting the number of compression points detected by the compression point detection means as a formation index. 10. A formation inspection apparatus for inspecting the formation of an inspection object, a light source for irradiating the inspection object, a first deflection filter arranged between the light source and the inspection object, A color filter that extracts a specific color component from the transmitted light of the target, a beam splitter that separates the light extracted by the color filter into two lights, and a light beam that passes one of the lights separated by the beam splitter. A second deflection filter set to the same deflection angle as the first deflection filter, and a third deflection filter set to a deflection angle orthogonal to the first deflection filter that passes the other light separated by the beam splitter. A deflecting filter, a first imaging unit that captures the first image of the inspection target from the light that has passed through the second deflecting filter, and a light that has passed through the third deflecting filter. A second imaging unit that captures a second image of the inspection target, and a second image that is captured by the second imaging unit is subtracted from the first image that is captured by the first imaging unit. 1. A formation inspection device, comprising: a subtraction unit that performs the subtraction processing;