JP2019066314A - Inspection device, method for inspection, and program for inspection device - Google Patents

Abstract

To provide an inspection device, for example, that can detect defects of an inspection targe more accurately.SOLUTION: The present invention relates to an inspection device 10 for inspecting a conveyed sheet-like inspection target (S) on the basis of an image from imaging means (20) with a linear imaging region. The present invention also relates to acquiring an image from imaging means with the imaging region inclined with respect to the conveyance direction (y) and the right-angle direction (x); and detecting a defect of an inspection target from the image according to the angle (θ) of the inclination of the imaging region of the imaging means (S5).SELECTED DRAWING: Figure 5

Description

  The present invention relates to an inspection apparatus, an inspection method, and a program for the inspection apparatus.

  In the production of an optical film or the like, an ink is applied using a nozzle in order to impart optical characteristics to a film as a substrate. At this time, due to vibration or the like of a pump used to deliver the ink to the nozzles, unevenness in the film thickness of the applied ink may occur in the film transport direction. On the other hand, sheet-like products such as optical films are generally inspected for defects in a roll-to-roll condition on a rewinder, but unevenness is caused by vibration during transport or by flapping of sheet-like products. It affects the accuracy of detection of As a method of eliminating the influence of noise due to such vibration etc., for example, in Patent Document 1, a first illumination unit and a second illumination unit that irradiate light to an inspection object with a constant brightness at a constant speed Alternately turning on / off to obtain a first image and a second image of the inspection object illuminated by the first illumination unit and the second illumination unit, and when vibration noise is generated in the inspection object; A vibration noise correction device for an optical inspection system is disclosed that replaces the image of the image with a second image.

JP, 2013-108975, A

  However, in the prior art, in the method of switching on / off of two light sources for imaging, by using two light sources properly, the angles of illumination for illuminating the film to be inspected are different from each other. Therefore, even if the defect is the same, there may be differences in the intensity of light and dark of the defect shown in the image, and there may be differences in the ability to detect the defect depending on which illumination is used.

  Therefore, the present invention has been made in view of the above problems and the like, and an example of the problem is to provide an inspection device and the like which detects and inspects a defect of an inspection object with higher accuracy. .

  In order to solve the above problems, the invention according to claim 1 is an inspection apparatus for inspecting a sheet-like inspection object being conveyed based on an image from an imaging unit having a linear imaging area. Image acquisition means for acquiring an image from the imaging means arranged with the imaging area inclined with respect to the direction perpendicular to the direction of conveyance, and the image according to the angle of inclination of the imaging area of the imaging means And detection means for detecting a defect of the inspection object.

  The invention according to claim 2 is the inspection apparatus according to claim 1, wherein the shear deformation means performs shear deformation of the image acquired from the imaging means in accordance with the angle of inclination of the imaging area of the imaging means. And the detection means detects a defect of the inspection object from the sheared image.

  The invention according to claim 3 is the inspection apparatus according to claim 1 or 2, wherein averaging is performed on the image before the defect of the inspection object is detected by the detection means. It is characterized by further comprising filter means.

  The invention according to claim 4 is the inspection apparatus according to any one of claims 1 to 3, wherein the direction of photographing of the photographing means with respect to the vertical direction of the surface of the inspection object It is characterized in that the photographing means and the illumination means are arranged such that the direction of the illumination means illuminating the surface of the inspection object is the same.

  The invention according to claim 5 is the inspection method for inspecting the sheet-like inspection object being transported based on the image from the imaging unit having the linear imaging area, wherein the image acquiring unit is An image acquisition step of acquiring an image from the imaging means disposed by tilting the imaging area with respect to a direction perpendicular to the direction, and a detection means corresponding to an angle of inclination of the imaging area of the imaging means; And detecting the defect of the inspection object from the image.

  The invention according to claim 6 is a program for an inspection apparatus for inspecting a sheet-like inspection object being conveyed based on an image from an imaging unit having a linear imaging area, the computer comprising Image acquisition means for acquiring an image from the image pickup means disposed with the image pickup area inclined with respect to the direction perpendicular to the direction of the image, and the image according to the angle of inclination of the image pickup area of the image pickup means It is characterized by functioning as a detection means which detects the fault of the said test object from this.

  According to the present invention, the image from the imaging means disposed with the imaging area inclined with respect to the direction perpendicular to the transport direction is acquired, and the inspection object is inspected from the image according to the inclination angle of the imaging area of the imaging means. Since the noise due to vibration or rattling can be distinguished from the defect of the inspection object by detecting the defect of B, the defect of the inspection object can be detected with higher accuracy.

It is a schematic diagram which shows the outline | summary structural example of the test | inspection system which concerns on embodiment of this invention. It is a schematic diagram which shows an example of the arrangement | positioning relationship between the illuminating device with respect to the sheet | seat of test object, and an imaging device. It is a schematic diagram which shows an example of the arrangement | positioning direction of the imaging device with respect to the sheet | seat of test object. It is a block diagram which shows an example of a outline | summary structure of the test | inspection apparatus of FIG. It is a flowchart which shows the operation example of a test | inspection apparatus. It is a schematic diagram which shows an example of an image. It is a schematic diagram which shows an example of an image. It is a schematic diagram which shows an example of the image after shear deformation. It is a schematic diagram which shows an example of the image after shear deformation. It is a schematic diagram which shows an example of a smoothing filter. It is a schematic diagram which shows an example of the various line from which an angle differs. It is a schematic diagram which shows an example of the image after the smoothing process of the image of FIG. 9A.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiment described below is an embodiment when the present invention is applied to an inspection system.

[1. Configuration and Function of Inspection System 1]
(1.1 Configuration and Function of Inspection System 1)
First, a configuration and an outline function of an inspection system according to an embodiment of the present invention will be described using FIGS. 1 to 3.

  FIG. 1 is a schematic view showing an example of a schematic configuration of an inspection system according to an embodiment of the present invention. FIG. 2 is a schematic view showing an example of the arrangement relationship between the illumination device and the photographing device with respect to the sheet to be inspected. FIG. 3 is a schematic view showing an example of the arrangement direction of the photographing device with respect to the sheet to be inspected.

  As shown in FIG. 1, the inspection system 1 includes a conveyance device 3 for conveying the sheet S unwound from the roll, an inspection device 10 for inspecting the sheet S which is an example of a sheet-like inspection object, and The imaging apparatus 20 which image | photographs the surface, and the illuminating device 30 which illuminates the sheet | seat S for imaging | photography are provided. Here, the ink is applied to the surface of the film sheet S as a base material using a nozzle in the previous step in order to impart optical characteristics. The inspection apparatus 10 may perform inspection after applying the ink to the unwound sheet S by a nozzle (not shown).

  As shown in FIG. 2, the transport device 3 has a roll 3a for unwinding the sheet S, a roll 3b for winding the inspected sheet S, and a guide roll 3c for guiding the unwound sheet S. The sheet S is conveyed in the y-axis direction.

  As shown in FIG. 2, the inspection device 10 is connected to the transport device 3, the photographing device 20, the lighting device 30 and the like. The inspection device 10 acquires positional information of the unwound sheet S from the conveyance device 3. The inspection device 10 acquires image data from the imaging device 20. The inspection device 10 controls the illumination of the illumination device 30.

  The imaging device 20 is, for example, a color or black and white line sensor having an imaging element such as a charge coupled device (CCD) sensor or a complementary metal oxide semiconductor (CMOS) sensor. The imaging device 20 is an example of an imaging unit having a linear imaging region with respect to a subject. The linear imaging region may have one pixel in a direction perpendicular to the linear direction or may have a plurality of pixels. As shown in FIG. 3, the sheet S is disposed so as to be inclined at an angle θ with respect to the width direction (x-axis direction) of the sheet S which is a direction perpendicular to the conveyance direction (y-axis direction). For example, an angle θ of 15 ° to 45 ° is preferable. The photographing device 20 only needs to cover the width direction (x-axis direction) of the sheet S, and may be one or more. When the number of imaging devices 20 is small, a line sensor with a long line direction is required.

  The imaging apparatus 20 may be an area sensor having a two-dimensional imaging element instead of a line sensor having a one-dimensional imaging element. In this case, the imaging area is one as an example of the imaging unit having a linear imaging area. By restricting the dimensions to dimensions, it is possible to shoot as in the line sensor. The area sensor may be arranged with the x-axis and y-axis areas of the imaging area of the area sensor tilted at an angle θ with respect to the x-axis, and the imaging area may be limited to one-dimensional pixels in parallel to the x-axis . The area sensor is not inclined, that is, the x axis of the imaging area of the area sensor is parallel to the width direction of the sheet S, and the x axis and the y axis of the imaging area of the area sensor to the x axis In contrast, the imaging region may be limited to one-dimensional pixels in parallel to the straight line of the angle θ.

  The illumination device 30, which is an example of illumination means for illuminating the surface of the inspection target, is, for example, a linear light emitter such as a fluorescent lamp or a light emitting diode (LED) element. As shown in FIG. 1, the illumination device 30 is disposed parallel to the imaging device 20. Furthermore, as shown in FIG. 2, the lighting device 30 is configured such that the incident angle φ and the reflection angle φ are the same with respect to the sheet S so that the photographing device 20 can easily receive the reflected light by the lighting device 30. It is preferred that the

  As described above, in the photographing device 20 and the lighting device 30, the photographing direction of the photographing unit and the direction of the lighting unit illuminating the surface of the inspection target with respect to the vertical direction of the surface of the inspection target are It is an example of the imaging | photography means and illumination means arrange | positioned so that it may become the same in the relationship of an incident angle and a reflection angle.

(1.2 Configuration and Function of Inspection Device 10)
Next, the configuration and function of the inspection apparatus 10 will be described with reference to FIG.

  FIG. 4 is a block diagram showing an example of a schematic configuration of the inspection apparatus 10.

  As shown in FIG. 2, the inspection apparatus 10, which is a computer, has a control unit 11 that controls the inspection apparatus 10, a storage unit 12 that stores data, a communication unit 13 that communicates with the imaging apparatus 20 and the like, and information An output unit 14 for displaying and an operation unit 15 for receiving an input are provided.

  The control unit 11 includes, for example, a central processing unit (CPU), a read only memory (ROM), and a random access memory (RAM). In the control unit 11, the CPU reads various control programs stored in the ROM and the RAM, and executes various image processing. The control unit 11 controls each unit such as the storage unit 12 of the inspection device 10. The control unit 11 may read out and execute a recording medium or the like storing these programs.

  The storage unit 12 is configured of, for example, a hard disk drive, a silicon disk, or the like. The storage unit 12 stores captured image data, a filter for image processing, and the like.

  The storage unit 12 may also store various programs such as an operating system and a server program. The various programs may be acquired from, for example, another server or the like via a network, or may be recorded on a recording medium and read via a drive device.

  The communication unit 13 controls communication with the conveyance device 3, the photographing device 20, the lighting device 30, and the like.

  The output unit 14 is configured of, for example, a liquid crystal display element or an EL (Electro Luminescence) element.

  The operation unit 15 includes, for example, a keyboard and a mouse.

[2. Operation of inspection system]
Next, the operation of the inspection system according to an embodiment of the present invention will be described using FIGS. 2 to 8.

(2.1 Operation example of inspection system)
First, an operation example of the inspection system 1 will be described with reference to FIGS. 5 to 9B.

  FIG. 5 is a flowchart showing an operation example of the inspection apparatus. 6A and 6B are schematic diagrams showing an example of an image. 7A and 7B are schematic views showing an example of an image after shear deformation. FIG. 8 is a schematic view showing an example of the smoothing filter. FIG. 9A is a schematic view showing an example of various lines having different angles. FIG. 9B is a schematic view showing an example of the image after the smoothing processing of the image of FIG. 9A.

  The transport device 3 of the inspection system 1 unwinds the sheet S from the roll 3a by a predetermined amount. The sheet S unwound from the roll 3a passes through the guide roll 3c at a predetermined speed and is taken up by the roll 3b.

  The inspection device 10 acquires data of the encoder of the roll 3 a from the transport device 3.

  The photographing device 20 photographs the sheet S illuminated by the lighting device 30 being conveyed at a predetermined speed between the guide rolls 3c.

  As shown in FIG. 5, the inspection apparatus 10 acquires an image (step S1). Specifically, the control unit 11 of the inspection device 10 acquires, from the imaging device 20, image data of the sheet S being conveyed at a predetermined speed. The control unit 11 acquires, as a two-dimensional image, image data of the sheet S which has passed through the linear imaging region of the imaging device 20 for a predetermined time. The control unit 11 may acquire the image data buffered in the imaging device 20 at predetermined time intervals and acquire the image data so as to be a two-dimensional image.

  In the case where there is no unevenness in the application of ink and there is vibration of the imaging device 20 or fluttering of the sheet S, as shown in FIG. 6A, a bright and dark line L1 appears in a black band in the x-axis direction. On the other hand, when uneven application of ink occurs, as shown in FIG. 6B, a bright and dark line L2 of the angle θ of inclination of the imaging region appears in a black band with respect to the x axis. The line L2 is a nonuniformity defect and is an example of a defect to be inspected.

  As described above, the inspection apparatus 10 functions as an example of an image acquisition unit that acquires an image from the imaging unit disposed with the imaging region inclined with respect to the direction perpendicular to the transport direction.

  Next, the inspection apparatus 10 shears and deforms the image (step S2). Specifically, the control unit 11 inclines the x-axis by an angle θ so that the image captured by the imaging device 20 in which the imaging region is arranged by inclining the angle θ in the width direction of the sheet S Image processing of transformation shear deformation. That is, the control unit 11 shifts the pixel in the y direction according to the value of the x 'axis.

  As shown in FIG. 7A, after image processing of shear deformation at an angle θ, the light and dark line L1 is inclined at an inclination angle θ of the imaging region with respect to the x ′ axis after conversion of the x axis. On the other hand, as shown in FIG. 7B, after image processing of shear deformation at an angle θ, the light and dark lines L2 become parallel to the x ′ axis after conversion of the x axis.

  As described above, the inspection apparatus 10 functions as an example of a shear deformation unit that shears and deforms the image acquired from the imaging unit according to the angle of inclination of the imaging region of the imaging unit.

  Next, the inspection apparatus 10 performs an averaging filter process (step S3). As shown in FIG. 8, the control unit 11 is a filter having a high aspect ratio with respect to the x ′ axis direction (for example, x ′: y = 512: 15, 8: 1, 16: 1, 32: 1, etc.) Perform processing using When the filter processing is performed, for example, in FIG. 7A and FIG. 7B, since the image is integrated in the x 'axis direction, the angled unevenness disappears, and only the unevenness defect parallel to the x' axis remains in the image become.

  Although it is not an image after shear deformation, as shown in FIG. 9A, when the averaging filter process is performed on light and dark lines at various angles with respect to the x axis, as shown in FIG. 9B, the x axis Although light and dark lines close to parallel to each other remain in the image, light and dark lines moving away from the direction of the x-axis tend to be averaged and blurred.

  As shown in FIG. 9B, when the angle θ is too small (0 to 10 °), noise due to vibration or the like can not be eliminated, so the angle θ is preferably 15 ° or more.

  In addition, as the angle θ is increased, the inspection range becomes narrower by cos θ times than when θ = 0 °, and becomes approximately 0.71 times when θ = 45 °. As the number of imaging devices required for the inspection increases as the inspection range narrows, the cost for the device increases accordingly, so the angle θ is preferably 45 degrees or less.

  When the averaging filter is applied to the image after shear deformation, the light and dark lines L of the unevenness defects parallel to the x ′ axis remain but the light and dark lines L1 inclined at the angle θ with respect to the x ′ axis Becomes blurry and thinly spread in the y-axis direction.

  Thus, the inspection apparatus 10 functions as an example of an averaging filter unit that performs averaging filter processing on an image before the detection unit detects a defect of the inspection target.

  Next, the inspection apparatus 10 extracts the nonuniform defect candidate (step S4). Specifically, the control unit 11 extracts line segments that are parallel to the x ′ axis after the conversion of the x axis, that is, candidates for unevenness defects. The control unit 11 extracts a dark portion of the bright and dark line as a nonuniformity defect candidate. For example, the averaged image is converted into a negative image and differentiated in the y-axis direction to extract line segments parallel to the x'-axis direction.

  Next, the inspection apparatus 10 determines an inspection target (step S5). Specifically, the control unit 11 determines that the extracted line segment parallel to the x'-axis direction is a line having a predetermined length (a length of 1/3, 2/3, etc. with respect to the width of the image) Determine whether it is a minute or not.

  As described above, the inspection apparatus 10 functions as an example of a detection unit that detects a defect of the inspection target from the image according to the inclination angle of the imaging region of the imaging unit. In addition, the inspection apparatus 10 functions as an example of a detection unit that detects a defect of the inspection object from the sheared image.

  If the length is longer than the predetermined length, the control unit 11 combines the unrolling information from the transport device 3 with the position information of the y component because the information of the position of the y component corresponds to the position of the sheet S. It is stored in the storage unit 12 in association with the identified ID.

  Next, the inspection apparatus 10 determines whether or not the process ends (step S6). For example, the control unit 11 determines whether or not the conveyance of the sheet S by the conveyance device 3 has ended based on the data from the conveyance device 3. Further, the control unit 11 may determine the power supply of the inspection apparatus 10 or the end of the program.

  If not (step S6; NO), the inspection apparatus 10 returns to step S1 and acquires an image of the sheet S being conveyed.

  If not (step S6; YES), the inspection apparatus 10 ends the inspection.

  The control unit 11 may extract a line segment inclined at an angle θ with respect to the x-axis in step S4 without determining the shear deformation process in step S2, and determine the inspection target in step S5.

  In addition, the smoothing filter process of step S3 may be performed on an image which has not been subjected to the shear deformation process of step S2. In this case, the smoothing filter process is set so that the line L2 remains and the line L1 disappears in FIG. 6B in accordance with the inclination angle θ of the imaging region of the imaging device 20. For example, the smoothing filter in step S3 is a filter that is sheared. Thus, the inspection apparatus 10 functions as an example of an averaging filter unit that performs averaging filter processing on an image before the detection unit detects a defect of the inspection target.

  As described above, according to the present embodiment, the image from the imaging device 20 disposed with the imaging region inclined with respect to the direction (x-axis direction) perpendicular to the transport direction is acquired, and the imaging region of the imaging device 20 is inclined. Noises due to vibration of the imaging device 20 or the illumination device 30, fluttering of the sheet S, etc. and defects of the inspection object by detecting defects of the inspection object such as the sheet S from the image according to the angle of It appears and can be distinguished according to the angle of the 20 imaging regions, so that the defect of the inspection object can be detected with higher accuracy.

  Since the imaging device 20 is disposed with the imaging region inclined with respect to the direction (x-axis direction) perpendicular to the transport direction, erroneous detection of unevenness due to vibration of the imaging device 20 or the like and flapping of the sheet S is prevented. ing.

  When the image acquired from the imaging device 20 is sheared according to the angle of inclination of the imaging area of the imaging device 20 and a defect of the sheet S is detected from the sheared image, the defect of the sheet S in a desired direction Can be made to appear. In particular, the defect of the sheet S can appear in the direction perpendicular to the transport direction, and the defect of the sheet S can be easily detected.

  When the averaging filter process is performed on the image before detecting the defect of the inspection object, one of the noise due to the vibration of the photographing device 20 and the illumination device 30 and the flapping of the sheet S and the defect of the inspection object is averaged. It will be easier to distinguish because it will disappear.

  In the vertical direction (z-axis direction) of the surface of the sheet S, which is an example of the inspection target, the photographing direction of the photographing device 20 and the direction of the illumination device 30 illuminating the surface of the inspection target are the same In the case where the imaging device 20 and the illumination device 30 are arranged, the light reflected by the normal surface to be inspected becomes easy to enter the imaging device 20, and the distinction between the noise and the defect portion becomes easy to be clear. , Makes it easy to detect defects with high accuracy.

1: Inspection system 10: Inspection device 20: Imaging device (imaging means)
30: Lighting device (lighting means)
S: Sheet (subject to inspection)

Claims (6)

An inspection apparatus for inspecting a sheet-like inspection object being conveyed based on an image from an imaging unit having a linear imaging area,
An image acquisition unit configured to acquire an image from the imaging unit disposed by inclining the imaging region with respect to a direction perpendicular to the transport direction;
Detection means for detecting a defect of the inspection object from the image according to the angle of inclination of the imaging area of the imaging means;
An inspection apparatus comprising: In the inspection apparatus according to claim 1,
It further comprises shear deformation means for shearing the image acquired from the photographing means in accordance with the angle of inclination of the photographing area of the photographing means.
The inspection apparatus characterized in that the detection means detects a defect of the inspection object from the sheared image. In the inspection apparatus according to claim 1 or 2,
An inspection apparatus further comprising averaging filter means for performing averaging filter processing on an image before the detection means detects a defect of the inspection object. The inspection apparatus according to any one of claims 1 to 3.
The direction of photographing of the photographing means and the direction of the illumination means for illuminating the surface of the inspection object are the same in the relation of the incident angle and the reflection angle with respect to the vertical direction of the surface of the inspection object. An inspection apparatus characterized in that the photographing means and the illumination means are disposed. In an inspection method for inspecting a sheet-like inspection object being conveyed based on an image from an imaging unit having a linear imaging area,
An image acquisition step of acquiring an image from the imaging unit disposed by tilting the imaging area with respect to a direction perpendicular to the direction of conveyance;
A detection step of detecting a defect of the inspection object from the image according to an angle of inclination of the imaging area of the imaging unit;
An inspection method characterized by including. In a program for an inspection apparatus for inspecting a sheet-like inspection object being conveyed, based on an image from an imaging unit having a linear imaging area,
Computer,
An image acquisition unit configured to acquire an image from the imaging unit disposed by inclining the imaging region with respect to a direction perpendicular to the transport direction;
A program for an inspection apparatus characterized in that it functions as a detection unit that detects a defect of the inspection object from the image according to an angle of inclination of the imaging region of the imaging unit.