Film inspection device, film inspection method, and program

Abstract

The invention relates to a film inspection apparatus, a film inspection method, and a program. The present invention easily detects defects generated in a thin film without manual monitoring or work. In a thin film inspection device for optically inspecting defects occurring in a thin film in an overlapping state, light is irradiated to the thin film by a light source (step S1), and at least diffused light among light reflected by the thin film is detected by a camera (optical sensor) (step S2). A thin film inspection device detects defects by extracting an inspection region at an inspection timing from first image data obtained from an output signal of a camera (step S5), and performing data processing on second image data corresponding to the inspection region (step S6).

Description

Technical Field

[0001] The present invention relates to a film inspection device, a film inspection method and a program. Background Art

[0002] Prior art literature

[0003] When a long resin film is rolled into a roll, various defects are generated due to the state of the film (film thickness deviation, residual stress, temperature, humidity) and the conditions of rolling (tension, speed, air entrapment). Defects in the film include, for example, gauge bands, longitudinal wrinkles, and oblique wrinkles.

[0004] A film inspection device has been proposed that detects defects in a film by taking an image of the film being wound with a camera or the like instead of manually monitoring the film to optically inspect the defects in the film (see Patent Document 1).

[0005] Patent Document 1: Japanese Patent Application Publication No. 2023-017169

[0006] However, for a long film roll, in order to observe it from the beginning to the end of winding, it is necessary to take a picture of the roll at each time. At this time, as the diameter of the roll changes, the distance between the roll surface and the fixed camera changes. As a result, the size of the film roll in the image obtained by the camera changes.

[0007] Therefore, it is necessary to extract the inspection area from the film rolls of different sizes in the image according to the timing of each inspection (shooting). In the above-mentioned prior art, a method for extracting the inspection area from the image obtained by shooting is described. Generally, as a method for extracting a range of interest from an image, the ROI function of the camera and the trimming of the image are listed. However, in the general method, a certain range can be extracted, but it is difficult to extract the correct inspection area. Alternatively, at each inspection timing, the user must manually specify the extraction range. Summary of the invention

[0008] The present invention has been made in view of the above-mentioned problems in the prior art, and an object of the present invention is to easily detect defects occurring in a thin film without requiring manual monitoring or work.

[0009] In order to solve the above-mentioned problems, the invention described in Technical Solution 1 is a film inspection device for optically inspecting defects generated in overlapping films, comprising: a light source for irradiating light to the film; an optical sensor for detecting at least diffuse light among the light reflected in the film; an inspection area extraction unit for extracting an inspection area at an inspection timing from the first image data obtained from the output signal of the optical sensor; and a defect detection unit for detecting the defect by performing data processing on the second image data corresponding to the inspection area.

[0010] The invention described in claim 2 is the thin film inspection device described in claim 1, wherein a plurality of the optical sensors are provided, and the inspection area extraction unit further removes overlapping ranges of the plurality of first image data obtained from each of the plurality of optical sensors.

[0011] The invention described in claim 3 is the thin film inspection device described in claim 1 or 2, wherein the inspection area extraction unit performs processing in the inspection area extraction unit by optical calculation using the size information of the thin film at the inspection timing and the setting information of the optical sensor.

[0012] The invention described in claim 4 is the thin film inspection device described in claim 1 or 2, wherein the film is wound in a roll shape, and the thin film inspection device uses the defects generated during the winding of the film as the inspection object.

[0013] The invention described in claim 5 is the thin film inspection device described in claim 1 or 2, wherein the optical sensor is an area sensor.

[0014] The invention described in Technical Solution 6 is provided with a reflection prevention plate in the thin film inspection device described in Technical Solution 1 or 2 so that the regular reflected light in the inspection area of ​​the thin film does not enter the optical sensor, and the reflection prevention plate is composed of a diffusion plate.

[0015] The invention described in claim 7 is provided with a display control unit in the thin film inspection device described in claim 1 or 2, which causes a display unit to display information on the inspection area extracted by the inspection area extraction unit and / or the defect detected by the defect detection unit.

[0016] The invention described in Technical Solution 8 is a film inspection method for optically inspecting defects generated in a film in an overlapping state, comprising: a process of irradiating light to the film through a light source; a process of detecting at least diffuse light in the light reflected in the film through an optical sensor; an inspection area extraction process, in which an inspection area extraction unit extracts an inspection area at an inspection timing from the first image data obtained from the output signal of the optical sensor; and a defect detection process, in which a defect detection unit performs data processing on the second image data corresponding to the inspection area, thereby detecting the defect.

[0017] The invention described in Technical Solution 9 is characterized in that in the thin film inspection method described in Technical Solution 8, there are multiple optical sensors, and in the inspection area extraction process, the overlapping ranges of the multiple first image data obtained from each of the multiple optical sensors are also removed.

[0018] The invention described in Technical Solution 10 is a thin film inspection method described in Technical Solution 8 or 9, wherein in the inspection area extraction step, the processing in the inspection area extraction step is performed by optical calculation using the size information of the thin film at the inspection timing and the setting information of the optical sensor.

[0019] The invention described in claim 11 is the thin film inspection method described in claim 8 or 9, wherein the film is wound into a roll shape, and in this thin film inspection method, the defects generated during the winding of the film are taken as the inspection object.

[0020] The invention described in Technical Solution 12 is the thin film inspection method described in Technical Solution 8 or 9, wherein the optical sensor is an area sensor.

[0021] The invention described in Technical Solution 13 is characterized in that, in the thin film inspection method described in Technical Solution 8 or 9, a reflection prevention plate is provided so that the regular reflected light in the light reflected in the inspection area of ​​the thin film does not enter the optical sensor, and the reflection prevention plate is composed of a diffusion plate.

[0022] The invention described in Technical Solution 14, in the thin film inspection method described in Technical Solution 8 or 9, includes a display control process, in which the display unit displays information on the inspection area extracted in the inspection area extraction process and / or the defects detected in the defect detection process.

[0023] The invention described in technical solution 15 is a program for causing a computer of a thin film inspection device that optically inspects defects generated in the thin film to function as an inspection area extraction unit and a defect detection unit, wherein the thin film inspection device comprises: a light source for irradiating light to the thin films in an overlapping state, and an optical sensor for detecting at least diffuse light in the light reflected in the thin film, the inspection area extraction unit extracts an inspection area at an inspection timing from the first image data obtained from the output signal of the optical sensor, and the defect detection unit detects the defect by performing data processing on the second image data corresponding to the inspection area.

[0024] The invention described in claim 16 is the program described in claim 15 , wherein the thin film inspection device includes a plurality of the optical sensors, and the inspection area extraction unit further removes overlapping ranges of the plurality of first image data obtained from each of the plurality of the optical sensors.

[0025] The invention described in claim 17 is the program described in claim 15 or 16, wherein the inspection area extraction unit performs processing by optical calculation using the size information of the film at the inspection timing and the setting information of the optical sensor.

[0026] The invention described in claim 18 is the program described in claim 15 or 16, wherein the film is wound into a roll shape, and the film inspection device takes the defects generated during the winding of the film as the inspection object.

[0027] The invention described in Technical Solution 19 is in the program described in Technical Solution 15 or 16, wherein the optical sensor is an area sensor.

[0028] The invention described in Technical Solution 20 is in the procedure described in Technical Solution 15 or 16, wherein a reflection prevention plate is provided in the film inspection device so that the regular reflected light in the inspection area of ​​the film does not enter the optical sensor, and the reflection prevention plate is composed of a diffuser.

[0029] The invention described in technical solution 21 enables the computer to function as a display control unit in the program described in technical solution 15 or 16, and the display control unit enables the display unit to display information on the inspection area extracted by the inspection area extraction unit and / or the defects detected by the defect detection unit.

[0030] According to the present invention, defects occurring in a thin film can be easily detected without requiring manual monitoring or work. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1It is a diagram showing the functional structure of the thin film inspection device in the first embodiment of the present invention.

[0032] Figure 2 A diagram for explaining the arrangement of light sources and cameras.

[0033] Figure 3 It is a perspective view showing the positional relationship between a light source and a camera with respect to a rolled film.

[0034] Figure 4 It is a diagram for explaining the arrangement of the reflection prevention plate.

[0035] Figure 5 1 is a flowchart showing a thin film defect detection process performed by the thin film inspection apparatus.

[0036] Figure 6 This is a flowchart showing the first inspection area extraction process.

[0037] Figure 7 is an example of a captured image.

[0038] Figure 8 It is a diagram for explaining the change in the size of the inspection area accompanying the change in the winding diameter of the film roll.

[0039] Fig. 9 This is a diagram for explaining a method of calculating a boundary position when extracting an inspection area from a captured image.

[0040] Fig. 10A This is a graph showing the relationship between the winding diameter of the film roll and the cutting position.

[0041] Fig. 10B This is a graph showing the relationship between the winding diameter of the film roll and the cut-off lower position.

[0042] Fig.11 This is a diagram for explaining the imaging range in the width direction of the film, etc.

[0043] Fig.12 It is a flowchart showing data processing.

[0044] Fig.13 This is an example of the inspection result screen.

[0045] Fig.14 This is a diagram for explaining the overlap amount of imaging ranges by three cameras included in the thin film inspection apparatus according to the second embodiment.

[0046] Fig.15 This is a flowchart showing the second inspection area extraction process.

[0047] Fig.16 This is a diagram for explaining a method for calculating the overlap amount of an imaging range.

[0048] Fig.17A This is a diagram for explaining the overlapping range with respect to the first image data obtained from three cameras respectively.

[0049] Fig. 17B This is a diagram showing the first image data after the overlapping range has been removed. DETAILED DESCRIPTION

[0050] Industrial Applicability

[0051] Hereinafter, embodiments of a thin film inspection apparatus, a thin film inspection method, and a program according to the present invention will be described with reference to the accompanying drawings. However, the scope of the present invention is not limited to the illustrated examples.

[0052] [First embodiment]

[0053] Figure 1 The functional structure of the thin film inspection device 10 in the first embodiment is shown. The thin film inspection device 10 includes a light source 11, a camera 12 as an optical sensor, and an information processing device 20. The thin film inspection device 10 is wound in a roll shape and optically inspects defects generated in the overlapped film F. The thin film inspection device 10 inspects defects generated in the winding of the long film F.

[0054] The material of film F is not particularly limited, but generally includes polycarbonate resin, polysulfone resin, acrylic resin, polyolefin resin, cyclic olefin resin, polyether resin, polyester resin, polyamide resin, polysulfide resin, unsaturated polyester resin, epoxy resin, melamine resin, phenolic resin, diallyl phthalate resin, polyimide resin, polyurethane resin, polyvinyl acetate resin, polyvinyl alcohol resin, styrene resin, cellulose acetate resin, vinyl chloride resin, etc.

[0055] Furthermore, for example, an example in which the thickness of the film F is 1 to 1000 μm and the width of the film F is 0.1 to 5 m is used.

[0056] Examples of defects in the film F include thickness bands, longitudinal wrinkles, and oblique wrinkles.

[0057] Thickness bands are defects that appear darker than the surroundings and are dark streaks in the circumferential direction of the roll. Thickness bands are caused by adhesion between films F. Thickness bands are also called black bands or convex stripes.

[0058] Longitudinal wrinkles are rib-like deformations in the circumferential direction of the roll. Longitudinal wrinkles are also called lantern-shaped buckling.

[0059] Oblique wrinkles are deformations in an oblique direction relative to the circumferential direction and the width direction of the roll, and have pyramid-shaped or chain-shaped concavities and convexities. Oblique wrinkles are also called diamond bends.

[0060] The light source 11 irradiates light to an area including the inspection area of ​​the film F. The light source 11 irradiates light uniformly in the width direction of the roll-shaped film F. Here, the width direction of the film F refers to a direction perpendicular to the long side direction of the film F and parallel to the film surface. In addition, uniform in the width direction means that the illuminance in the film F is substantially the same in the width direction of the film F. For example, the difference between the maximum value and the minimum value of the illuminance is less than a specified value.

[0061] The inspection area is an area to be detected as a defect at each inspection timing. The inspection area is a portion irradiated by the light source 11 and where diffuse light of light reflected by the film F is observed, without any surrounding reflection.

[0062] The camera 12 is an optical sensor that optically reads an area including the inspection area of ​​the film F. The camera 12 includes an imaging element, a lens, etc. As the imaging element, a CCD (Charge Coupled Device), a CMOS (Complementary Metal Oxide Semiconductor), etc. are used. The camera 12 is an area sensor that generates two-dimensional image data from output signals of each imaging element. The camera 12 detects at least diffuse light of the light irradiated by the light source 11 and reflected by the film F.

[0063] In the first embodiment, the camera 12 has an imaging range covering the entire width direction of the film F. In other words, the camera 12 simultaneously reads the entire width direction of the film F through one imaging. The camera 12 can detect light in the visible light region and light in the infrared region.

[0064] The information processing device 20 includes a control unit 21, I / F (Interface) 22, 23, a communication unit 24, a display unit 25, an operation unit 26, a storage unit 27, a timing unit 28, a film size measuring unit 29, etc. The various units constituting the information processing device 20 are connected via a bus. The information processing device 20 is composed of a PC (Personal Computer) or the like.

[0065] The control unit 21 includes a CPU (Central Processing Unit), a RAM (Random Access Memory), etc. The control unit 21 uniformly controls the processing actions of each unit of the information processing device 20 (thin film inspection device 10). Specifically, the CPU reads various processing programs stored in the storage unit 27 and expands them to the RAM, and performs various processing in cooperation with the programs.

[0066] The I / F 22 is an interface for connecting to the camera 12. The I / F 22 transmits a control signal to the camera 12, and receives image data (first image data) obtained by imaging the film F from the camera 12.

[0067] The I / F 23 is an interface for connecting to the light source 11. The I / F 23 transmits a control signal for controlling irradiation of light by the light source 11 to the light source 11.

[0068] The communication unit 24 is composed of a network interface, etc. The communication unit 24 transmits and receives data to and from an external device connected via a communication network such as a LAN (Local Area Network).

[0069] The display unit 25 includes a monitor such as an LCD (Liquid Crystal Display) and displays various screens in accordance with instructions of a display signal input from the control unit 21 .

[0070] The operation unit 26 includes a keyboard having cursor keys, character and numeric input keys, and various function keys, and a pointing device such as a mouse. The operation unit 26 outputs an operation signal input by operating a key on the keyboard or operating the mouse to the control unit 21 .

[0071] The storage unit 27 is composed of a HDD (Hard Disk Drive), an SSD (Solid State Drive), etc. The storage unit 27 stores various processing programs, data necessary for executing the programs, and the like.

[0072] The storage unit 27 stores setting information (camera setting information) of the camera 12. The camera setting information includes the focal length of the camera lens, the sensor size, the number of sensor pixels, the distance between the camera lens and the winding center of the film roll, and the like.

[0073] The sensor size is the size of the imaging element of the camera 12. Here, the length of the imaging element in the width direction of the film F is used as the sensor size.

[0074] The number of sensor pixels is the number of pixels of the imaging element of the camera 12. Here, as the number of sensor pixels, the number of pixels of the imaging element in the width direction of the film F is used.

[0075] The film roll is a roll-shaped portion on which the film F is wound.

[0076] The timekeeping unit 28 includes a timekeeping circuit (RTC: Real Time Clock), and measures the current time with the timekeeping circuit and outputs the current time to the control unit 21 .

[0077] The film size measuring unit 29 measures the size of the film F during the winding of the film F. In other words, the film size measuring unit 29 acquires the size information (film size information) of the film F at the inspection timing. The film size information includes the film width, the winding diameter, and the like.

[0078] The film width is the length in the width direction of the film F. The film size measuring unit 29 measures the film width using a laser distance sensor, a photoelectric sensor, or the like.

[0079] The winding diameter is the diameter of the roll of the film F. The film size measuring unit 29 uses a rotary encoder or the like to measure the winding length of the film F. The winding length is the length of the long side direction of the wound film F. The film size measuring unit 29 uses a laser, ultrasonic wave or the like to measure the film thickness of the film F. The film size measuring unit 29 calculates the winding diameter based on the winding length and the film thickness. In addition, the control unit 21 may also obtain the winding length and the film thickness from the film size measuring unit 29 to calculate the winding diameter.

[0080] Furthermore, the film size measuring unit 29 may use data measured by an external measuring device during the film F winding process.

[0081] In addition, since the width of the film does not change while the film F having the same width is being wound, a value set in advance for the film F being wound can be used.

[0082] The control unit 21 extracts the inspection region at the inspection timing from the first image data (the entire imaging region) obtained from the output signal of the camera 12 (optical sensor). That is, the control unit 21 functions as an inspection region extraction unit.

[0083] The inspection timing may be set so that all areas of the film F along the entire length in the long side direction can be inspected without omission (full range inspection mode). Alternatively, the inspection timing may be set so that only a part of the area along the long side direction of the film F becomes the inspection object (sampling inspection mode). In the full range inspection mode, all areas on the film F are included in the inspection area at any inspection timing. The user may also specify whether to perform the inspection in the full range inspection mode or the sampling inspection mode.

[0084] The control unit 21 extracts the inspection area by optical calculation using the film size information and camera setting information at the inspection timing.

[0085] The control unit 21 detects defects of the film F by performing data processing on the second image data corresponding to the inspection area extracted from the first image data. That is, the control unit 21 functions as a defect detection unit. For example, the control unit 21 detects the type of defect of the film F, the position of the defect, the intensity of the defect, etc.

[0086] Data processing includes image processing, defect determination processing and quantitative evaluation processing.

[0087] Here, the image processing is processing of image data obtained from the output signal of the camera 12. Specifically, the second image data corresponding to the inspection area extracted from the first image data is the processing target.

[0088] The defect determination process is a process of determining defects based on the image-processed data.

[0089] The quantitative evaluation process is a process of quantitatively evaluating defects based on the image processed data.

[0090] The control unit 21 causes the display unit 25 to display the inspection region extracted from the first image data and / or the information on the detected defect. That is, the control unit 21 functions as a display control unit.

[0091] Next, refer to Figure 2 , the configuration of the light source 11 and the camera 12 is described.

[0092] When observing the regular reflected light emitted by the light source 11 and reflected by the inspection object (film F), the brightness component of the light source 11 is observed. Whether it is observed by human eyes or by machine vision such as the camera 12, it is difficult to detect defects in the film F with regular reflected light.

[0093] When the camera 12 is arranged at the position P1 receiving the regular reflected light (brightness component) from the light source 11, the camera 12 basically captures the inspection object in the state reflected by the light source 11 (the inspection object overlapping the posture of the light source 11), and is therefore not suitable for defect detection.

[0094] The position of the camera 12 is avoided from the position P1 receiving the regular reflection of the light irradiated from the light source 11. In addition, the position P2 near the position P1 is not suitable for defect detection. Here, the position P1 near refers to the range affected by the regular reflection of the light from the light source 11.

[0095] The camera 12 may be disposed at a position (such as position P3 to P6 ) other than the position P1 and the vicinity thereof (such as the position P2 ), that is, at a position that receives diffuse light among the light reflected by the inspection target object.

[0096] Furthermore, when photographing the surface of the inspection object from a low angle (positions P5, P6, etc.), aberration problems are likely to occur, so the camera 12 is preferably set at a position where the angle between the photographing direction of the camera 12 and the inspection object surface is greater than a specified value.

[0097] Figure 3 It is a perspective view showing the positional relationship of the light source 11 and the camera 12 with respect to the roll-shaped film F. The light source 11 and the camera 12 are arranged in the vicinity, and the roll surface of the wound film F (the film F in the overlapped state) is the inspection object.

[0098] In addition, if the background (regular reflection) is reflected on the film surface in the observation range (corresponding to the inspection area) of the camera 12, it becomes a major factor that reduces the accuracy of defect determination. Therefore, it is preferable to provide a reflection prevention plate in the film inspection device 10 so that the regular reflection light among the light reflected in the inspection area of ​​the film F does not enter the camera 12.

[0099] From the start of winding of the film F to the end of winding, the winding diameter of the roll gradually increases.

[0100] like Figure 4 As shown, the winding diameter of the roll 41 just after winding begins is the smallest during the period from being wound to the roll 42 at the end of winding. Therefore, for the roll 41 just after winding begins, the area that becomes the object of regular reflection (the area where the light regularly reflected by the film surface enters the camera 12) is the largest.

[0101] Straight lines 43 and 44 are drawn from the two ends 41A and 41B in the circumferential direction of the observation range of the camera 12 toward the roll 41 just after winding, and these two straight lines 43 and 44 respectively draw straight lines (referred to as reflection straight lines) 45 and 46 in the direction of regular reflection on the film surface. The range 47 between these two reflection straight lines 45 and 46 is reflected in the observation range of the camera 12. Therefore, it is preferable to have a reflection prevention plate 48 in this range 47.

[0102] In the analysis using images, it is necessary to ensure sufficient light quantity when photographing. If the light quantity is insufficient, the difference between the normal part and the abnormal part on the film F becomes small, and there is a concern that the accuracy of defect determination will be reduced.

[0103] To solve such a problem, the reflection preventing plate 48 is formed of a diffuser plate with uniform surface roughness and color. The surface of the reflection preventing plate 48 facing the film F is preferably a color with high reflectivity such as white, blue, or gray.

[0104] Next, the operation of the thin film inspection apparatus 10 will be described.

[0105] Figure 5 1 is a flowchart showing a film defect detection process performed by the film inspection device 10. The film defect detection process is a process for detecting defects from the film F in an overlapped state during winding. This process is implemented by software processing based on the cooperation between the control unit 21 and the program stored in the storage unit 27. The film F is wound in such a manner that the conveying speed (line speed) in the long side direction of the film F is constant.

[0106] First, the control unit 21 controls the light source 11 via the I / F 23 to irradiate the film F with light (step S1 ).

[0107] The control unit 21 controls the camera 12 via the I / F 22 to cause the camera 12 to capture an image of a region including the inspection region of the film F (step S2 ).

[0108] The control unit 21 acquires the two-dimensional first image data (entire imaging region) generated by the camera 12 via the I / F 22 (step S3 ).

[0109] The control unit 21 saves the acquired first image data to the storage unit 27 (step S4). Specifically, the control unit 21 acquires the current time from the timing unit 28 and sets it as the inspection date and time, and stores the first image data in the storage unit 27 in correspondence with the inspection date and time. The image data (first image data) acquired by one shot is data for a part of the area in the circumferential direction of the wound film F. Therefore, the inspection date and time associated with the first image data corresponds to the position in the long side direction of the film F.

[0110] Next, the control unit 21 performs a first inspection region extraction process on the first image data acquired from the camera 12 (step S5 ).

[0111] Here, refer to Figure 6 , the first inspection area extraction process is explained.

[0112] The control unit 21 obtains the film size information and camera setting information at the inspection timing (step S11). Specifically, the control unit 21 obtains the film size information from the film size measuring unit 29. The film size information includes the film width, winding diameter, etc. In addition, the control unit 21 obtains the camera setting information stored in the storage unit 27. The camera setting information includes the focal length of the camera lens, the sensor size, the number of sensor pixels, the distance between the camera lens and the winding center of the film roll, etc.

[0113] Next, the control unit 21 extracts the inspection area from the first image data by optical calculation using the film size information and the camera setting information (step S12 ).

[0114] Figure 7 An example of a captured image 51 is shown. The captured image 51 corresponds to the entire area of ​​the first image data obtained by the camera 12.

[0115] The film roll 52 (roll-shaped film F) and the winding shaft 53 are shown in the captured image 51. The captured image 51 includes an inspection area 54 at the inspection timing (at the time of capturing). The captured image 51 may also include an area 55 where a light source is reflected.

[0116] When the winding diameter of the film roll 52 increases, the distance between the camera 12 and the surface of the film F decreases, and the size and position of the inspection area 54 in the captured image 51 change.

[0117] Figure 8 The following are examples of captured images 51A, 51B, and 51C having different inspection timings. The reference numerals used in the captured images 51A, 51B, and 51C are the same as those in FIG. Figure 7 Similarly, among the captured images 51A, 51B, and 51C, the film roll 52 has the smallest winding diameter in the captured image 51A, and has the largest winding diameter in the captured image 51C. The larger the winding diameter of the film roll 52, the larger the size of the inspection area 54.

[0118] Reference Fig. 9 Next, a method of calculating the boundary position when extracting the inspection area 54 from the captured image 51 will be described. Since the position of the inspection area 54 changes according to the winding diameter of the film roll 52, the cut-out range is changed for each winding diameter.

[0119] As a preliminary preparation, the cut-out upper position 56 and the cut-out lower position 57 for each winding diameter are recorded based on images acquired in advance (from the start to the end of winding of the roll).

[0120] Fig. 10A The relationship between the winding diameter [mm] of the film roll 52 and the cut-out upper position [pixel position] is shown. Based on this relationship, a linear approximation formula is created.

[0121] Cut-out upper position [pixel position] = 0.24 × winding diameter [mm] + 338

[0122] Fig. 10B The relationship between the winding diameter [mm] of the film roll 52 and the cut-out lower position [pixel position] is shown. A linear approximation formula is created based on this relationship.

[0123] Cut-out lower position [pixel position] = 0.34 × winding diameter [mm] + 325

[0124] The control unit 21 inputs the winding diameter into the created linear approximation formula for the inspection area 54 on the captured image 51, and obtains the upper cutout position 56 and the lower cutout position 57. In other words, the control unit 21 calculates the pixel position of the end of the film roll 52 in the circumferential direction of the inspection area 54 using the winding diameter.

[0125] Next, the control unit 21 obtains the cutting width positions 58 and 59 in the width direction of the film F (see FIG. 5 ) for the inspection area 54 on the captured image 51. Fig. 9 ).

[0126] like Fig.11 As shown in FIG. 1 , the imaging range [mm] of the width direction of the film F on the surface of the film F at the inspection timing is denoted as h range In addition, when the distance [mm] between the camera lens and the winding center of the film roll 52 is set to L r , the winding radius [mm] of the film roll 52 at the inspection timing is r. In addition, the focal length [mm] of the camera lens is f, and the sensor size [mm] in the width direction of the film F is s s When h is obtained by equation (1) range In addition, the winding radius r uses a value that is half of the winding diameter (roll diameter) included in the film size information.

[0127]

Number 1

[0128]

[0129] When the resolution [pix / mm] at the inspection timing is set to resol, the number of sensor pixels [pix] in the width direction of the film F is set to s pWhen , resol is obtained by equation (2).

[0130]

Number 2

[0131]

[0132] When the cut-out amount [pix] in the width direction is tpix, the film width [mm] at the inspection timing is w (refer to Fig.11 ), tpix is ​​calculated by equation (3). Tpix is ​​the number of pixels corresponding to the film width w.

[0133]

Number 3

[0134] t pix =w×resol…(3)

[0135] The control unit 21 sets the positions ±tpix / 2 from the image center position in the width direction of the film F of the first image data as the cut-out width positions 58 and 59. In other words, the control unit 21 uses the winding radius r, the film width w, the focal length f, the distance L between the camera lens and the winding center, and the cut-out width positions 58 and 59. r , sensor size s , the number of sensor pixels sp, to calculate the pixel position of the end portion of the inspection area 54 in the width direction of the film roll 52.

[0136] The control unit 21 extracts the inspection region 54 from the first image data (captured image 51 ) based on the cutout upper position 56 , the cutout lower position 57 , and the cutout width positions 58 and 59 obtained in this way.

[0137] Next, the control unit 21 stores the second image data corresponding to the examination region in the storage unit 27 (step S13). Specifically, in step S4, the control unit 21 stores the second image data in the storage unit 27 in association with the examination date and time associated with the first image data.

[0138] After the first inspection area extraction process, return to Figure 5 The control unit 21 performs data processing on the second image data corresponding to the extracted inspection area (step S6).

[0139] Here, refer to Fig.12 , the data processing is explained.

[0140] The control unit 21 divides the second image data into a plurality of regions in the width direction of the film F (step S21 ). Specifically, the control unit 21 divides the second image data into n regions a1 to an.

[0141] Next, the control unit 21 acquires image data of the area a1 (step S22), and performs mathematical processing on the image data of the area a1 (step S23). According to the type of defect to be inspected (thick band, longitudinal wrinkle, oblique wrinkle, etc.), appropriate mathematical processing is prepared.

[0142] Mathematical processing includes preprocessing, emphasis processing, signal processing, image feature extraction, etc.

[0143] As preprocessing, there are image retouching, low-pass filter, high-pass filter, Gaussian filter, median filter, bilateral filter, morphological transformation, color transformation (L*a*b*, sRGB, HSV, HSL), contrast adjustment, noise removal, restoration of blurred / shaked images, mask processing, Hough transform, projection transformation, etc.

[0144] Examples of the emphasis processing include a Sobel filter, a Scharr filter, a Laplacian filter, a Gabor filter, and a Canny method.

[0145] Signal processing includes basic statistics (maximum value, minimum value, mean value, median value, standard deviation, variance, quartiles), square sum and square root, difference, sum, product, ratio, processing for obtaining distance matrix, differential integration, threshold processing (binarization, adaptive binarization, etc.), Fourier transform, wavelet transform, peak detection (peak value, number of peaks, half-value width, etc.), etc.

[0146] As image feature extraction, template matching, SIFT feature, etc. can be cited.

[0147] The mathematical processing in step S23 corresponds to “image processing” on the second image data.

[0148] Specifically, the detection of the thickness band uses values ​​of a low-pass filter, a Gaussian filter, a median filter, a morphological transformation, a mask process, etc. as preprocessing, and basic statistics and threshold processing are used in signal processing.

[0149] Longitudinal wrinkles and oblique wrinkles are preprocessed using high-pass filters, emphasized using Sobel filters and Gabor filters, and signal processed using square sum square root, Fourier transform, basic statistics, etc.

[0150] Next, the control unit 21 performs threshold processing on the value (feature quantity) obtained by mathematical processing for the image data of the area a1 (step S24). The threshold processing is a process of determining whether it is a defect of the detection object based on one or more thresholds predetermined for each type of the defect of the detection object, and also determining the level (intensity) of the defect.

[0151] In the threshold processing of step S24, determining the presence and type of a defect corresponds to “defect determination processing.” In addition, in the threshold processing of step S24, classifying the defect into a plurality of levels according to the threshold value corresponds to “quantitative evaluation processing.”

[0152] For example, the control unit 21 classifies the defect into a plurality of levels according to a parameter (feature quantity) having a value of 1 to 100. Specifically, the control unit 21 classifies the defect as follows: when the value of the parameter is 1 to 10, it is level 1; when it is 11 to 30, it is level 2; when it is 31 to 60, it is level 3; and when it is 61 to 100, it is level 4.

[0153] The same processing is performed on the areas other than the area a1. For example, the processing of steps S25 to S27 performed on the image data of the area an is the same as the processing of steps S22 to S24.

[0154] After processing each area a1 to an, the control unit 21 integrates the results of each area a1 to an (step S28), and the data processing ends. Specifically, the control unit 21 generates data that associates each area (each position in the width direction of the film F) with the type and level of the detected defect.

[0155] After data processing, return to Figure 5 , the control unit 21 saves the processing results of the first inspection area extraction processing and / or data processing to the storage unit 27, and causes the display unit 25 to display the processing results (step S7). For example, the control unit 21 causes the display unit 25 to display the inspection area extracted in the first inspection area extraction processing. In addition, the control unit 21 stores the processing results of the data processing in the storage unit 27 in correspondence with the inspection date and time corresponding to the second image data. The processing results of the data processing include the type and level of defects detected in each area (position) divided along the width direction. The control unit 21 causes the display unit 25 to display information such as the type, position, level (intensity) of the detected defects.

[0156] The above is the end of the thin film defect detection process.

[0157] also, Figure 5 The film defect detection process shown is a process for inspecting the range corresponding to one shot. The film defect detection process is repeated by changing the inspection area in the long side direction of the film F as the wound film F moves, thereby obtaining the inspection result for each position in the long side direction of the film F.

[0158] In addition, Figure 5 In the process, the first inspection area extraction process is performed every time a picture is taken (refer to Figure 6 ) and data processing (see Fig.12 Alternatively, the control unit 21 may store image data obtained by multiple shootings in advance, and then perform the first inspection area extraction processing and data processing in a centralized manner.

[0159] Fig.13 An example of the inspection result screen 251 displayed on the display unit 25 is shown. The inspection result screen 251 displays the inspection result of the wound film F in real time. The inspection result screen 251 includes an inspection region image column 251A and a defect level column 251B.

[0160] The inspection area image column 251A displays the image of the inspection area extracted at each inspection timing. Specifically, the control unit 21 arranges the inspection areas that are longer in the width direction of the film F along the winding length (corresponding to the inspection time). Here, the control unit 21 adjusts the magnification of the second image data corresponding to each inspection area at each inspection timing so that the length of each inspection area in the width direction is consistent.

[0161] In the inspection area image column 251A, the horizontal direction indicates the position in the width direction of the film F. The vertical direction indicates the inspection timing according to the position in the long side direction of the film F (winding length). In addition, the inspection is performed on the entire range of the film F and every 100m of the winding length. Fig.13 Display of inspection results in .

[0162] The defect level column 251B displays the maximum level of defects generated at each inspection timing. The control unit 21 plots the maximum value of the level of defects detected from the inspection area obtained at each inspection timing with the horizontal axis being the winding length (corresponding to the inspection time). Here, the defect level is shown according to the type of each defect (thickness band, oblique wrinkle).

[0163] In the defect level column 251B, the defect level is also displayed every 100 m of the winding length. The displayed defect level value may be the maximum value of the defect level detected from the inspection area obtained at the inspection timing corresponding to the winding length. Alternatively, the inspection area image column 251A also includes the inspection area that is not displayed, and the maximum value of the defect level detected by the inspection of the winding length of 100 m may also be displayed in the defect level column 251B.

[0164] In addition to the above-mentioned examples, the control unit 21 may cause the display unit 25 to display the life and death monitoring information of the thin film inspection device 10. For example, the control unit 21 causes the display unit 25 to display the status information (operating / stopped / error) of each inspection process in the thin film inspection device 10. In addition, when an error occurs, the control unit 21 may notify the error by an alarm sound or the like.

[0165] Furthermore, the control unit 21 may cause the display unit 25 to display a search screen of past inspection results, search results, and the like.

[0166] As described above, according to the first embodiment, the control unit 21 extracts the inspection area at the inspection timing from the first image data obtained from the output signal of the camera 12 (optical sensor). Thus, the control unit 21 can extract the inspection area whose size and position change in the first image data.

[0167] Furthermore, since the control unit 21 detects defects of the film F based on the second image data corresponding to the inspection region, defects can be detected efficiently.

[0168] Therefore, the thin film inspection apparatus 10 can easily detect defects generated in the thin film F without requiring manual monitoring or work.

[0169] In addition, the control unit 21 extracts the inspection area by optical calculation using the film size information and camera setting information at the inspection timing. Thus, the control unit 21 can extract the inspection area by simple calculation.

[0170] Furthermore, by providing the reflection prevention plate 48 in the film inspection apparatus 10, it is possible to prevent a decrease in the detection accuracy of defects caused by reflection in the inspection area. The reflection prevention plate 48 prevents reflection of the background by preventing regular reflected light of the light reflected in the inspection area of ​​the film F from entering the camera 12.

[0171] Furthermore, the light reflected by the diffusion plate (reflection prevention plate 48) reaches the film F, is diffused in the film F, and reaches the camera 12 as diffused light. Thus, a larger amount of light can be secured compared to a case where there is no reflection prevention plate 48.

[0172] In addition, the control unit 21 causes the display unit 25 to display the extracted inspection area, information on detected defects, etc. Thus, the user can confirm the quality of the film F in real time. Therefore, it is possible to provide real-time feedback to the production process when the quality deteriorates, and improve the process based on data analysis, which is conducive to quality improvement and stable production.

[0173] Furthermore, the control unit 21 stores the inspection area image, defect detection results, and the like in the storage unit 27 so that past data can be searched and used.

[0174] [Second embodiment]

[0175] Next, a second embodiment to which the present invention is applied will be described.

[0176] Due to the restrictions on the installation position of the camera or the viewing angle of the camera lens, it is necessary to use a plurality of cameras in order to ensure the imaging range in the width direction of the film.

[0177] The second embodiment is different from the thin film inspection device 10 shown in the first embodiment in that it includes a plurality of cameras. The characteristic structure and processing of the second embodiment will be described below. Figure 1 The same results as those of the first embodiment are omitted in the description. In addition, the premise is that the plurality of cameras including lenses are identical and are disposed at the same distance from the film roll.

[0178] like Fig.14 As shown, the thin film inspection apparatus 10 in the second embodiment includes three cameras 12 .

[0179] The shooting range of each of the three cameras 12 covers the entire width direction of the film F. The distance between the camera 12 and the film surface changes with the change in the winding diameter of the film roll 52. As a result, the overlap amount of the first image data (shooting range) obtained by the adjacent cameras 12 changes according to the winding diameter of the film roll 52. Specifically, the overlap amount d1 of the shooting range when the winding radius r1 of the film roll 52 is relatively small is greater than the overlap amount d2 when the winding radius r2 is relatively large.

[0180] The camera setting information stored in the storage unit 27 also includes the inter-camera distance of the plurality of cameras 12. The inter-camera distance is the distance between the adjacent cameras 12 in the width direction of the film F.

[0181] The control unit 21 (inspection region extraction unit) removes overlapping ranges of a plurality of first image data obtained from a plurality of cameras 12 (optical sensors) respectively. In addition, the control unit 21 removes the overlapping ranges so that each region included in the overlapping range remains in any one of the first image data.

[0182] The control unit 21 combines the plurality of first image data in the width direction of the film F except for the overlapping range.

[0183] The control unit 21 extracts the inspection region at the inspection timing from the combined first image data.

[0184] Furthermore, the removal of duplicate ranges and the extraction of inspection areas may be performed before any processing.

[0185] The control unit 21 extracts the inspection area and removes the overlapping range by optical calculation using the film size information and camera setting information at the inspection timing.

[0186] Next, the operation of the thin film inspection apparatus 10 according to the second embodiment will be described. Figure 5 ) are described in detail below.

[0187] In the second embodiment, the control unit 21 acquires the first image data from each of the plurality of cameras 12 in step S3 of the thin film defect detection process.

[0188] In addition, the control unit 21 performs the following operation instead of step S5 of the thin film defect detection process: Fig.15 The second inspection area extraction process is shown.

[0189] In the second inspection area extraction process, first, the control unit 21 obtains the film size information and camera setting information at the inspection timing (step S31). Specifically, the control unit 21 obtains the film size information from the film size measuring unit 29. The film size information includes the film width, winding diameter, etc. In addition, the control unit 21 obtains the camera setting information stored in the storage unit 27. The camera setting information includes the focal length of the camera lens, the sensor size, the number of sensor pixels, the distance between the camera lens and the winding center of the film roll, the distance between cameras, etc.

[0190] Next, the control unit 21 removes the overlapping range from the first image data by optical calculation using the film size information and the camera setting information (step S32 ).

[0191] Reference Fig.16 , the method of calculating the overlap amount of the shooting range is explained.

[0192] When the repetition amount [mm] expressed as length (distance) is d mm , the imaging range [mm] of the film F surface in the width direction of the film F at the inspection timing is set to h range , Set the distance between cameras [mm] to L c When , we can use formula (4) to find d mm .

[0193]

Number 4

[0194] d mm =h range- L c …(4)

[0195] In addition, h is obtained by the above formula (1): range .

[0196] When the repetition amount [pix] expressed in pixels is set to d pix , when the resolution [pix / mm] at the inspection timing is set to resol, d is obtained by equation (5) pix .

[0197]

Number 5

[0198] d pix =d mm×resol…(5)

[0199] Furthermore, resol is obtained by the above formula (2).

[0200] In other words, the control unit 21 uses the winding radius r, the focal length f, the distance L between the camera lens and the winding center r , sensor size s 、Number of sensor pixels p , distance between cameras L c To calculate the repetition amount d pix calculate.

[0201] like Fig.17A As shown in FIG. 1 , the control unit 21 removes the overlapping ranges from the first image data 61, 62, and 63 obtained by each of the three cameras 12. Specifically, the control unit 21 removes the overlapping range 61A from the first image data 61. The control unit 21 removes the overlapping ranges 62A and 62B from the first image data 62. The control unit 21 removes the overlapping range 63A from the first image data 63. As the overlapping ranges 61A, 62A, 62B, and 63A, d pix / 2. For each first image data obtained by each camera 12, the overlapping range is removed from the boundary side in the width direction by d pix / 2, thereby preventing omission of data in the width direction of the film F.

[0202] Fig. 17B , which represents the first image data 61, 62, and 63 after removing the overlapping range. Fig.17A as well as Fig. 17B In the figure, flower-shaped and star-shaped marks are added to make it clear that the removed parts are not actually shown in the image.

[0203] Next, the control unit 21 combines the first image data with the overlapped range removed in the width direction of the film F (step S33). The image data generated by combining can be handled in the same manner as a series of image data (first image data of the first embodiment).

[0204] Next, the control unit 21 extracts the inspection area from the combined image data by optical calculation using the film size information and the camera setting information (step S34). The processing of step S34 is similar to the first inspection area extraction processing (see Figure 6 ) is processed in the same manner as step S12.

[0205] Next, the control unit 21 stores the second image data corresponding to the inspection region in the storage unit 27 (step S35). The process of step S35 is similar to the first inspection region extraction process (see Figure 6) is processed in the same manner as step S13.

[0206] The second inspection area extraction process is completed as described above.

[0207] As described above, according to the second embodiment, in the thin film inspection apparatus 10 having the plurality of cameras 12, the control unit 21 removes overlapping ranges of the plurality of first image data obtained from the plurality of cameras 12. Thus, the control unit 21 obtains the inspection area from the plurality of first image data in the correct amount.

[0208] The above-described embodiments are examples of the thin film inspection apparatus, thin film inspection method, and program of the present invention, and are not limited thereto. The detailed structure and detailed operation of each component constituting the apparatus can be appropriately changed within the scope of the present invention.

[0209] For example, the structures or processes in the above-described embodiments may be combined.

[0210] In the above-described embodiments, the case of detecting defects generated when the film F is wound into a roll shape has been described. Alternatively, the film inspection device 10 may detect defects generated when films F cut into a predetermined size are overlapped.

[0211] Furthermore, the control unit 21 may use a learning result based on machine learning when detecting defects from the second image data corresponding to the inspection region.

[0212] Specifically, the control unit 21 uses a machine learning model constructed by using the image-processed data as an explanatory variable and the result of human defect determination as a target variable in the defect determination process.

[0213] In addition, the control unit 21 uses a machine learning model constructed by using the image processed data as an explanatory variable and the quantitative evaluation result of the defect by a person as a target variable in the quantitative evaluation process. The control unit 21 classifies the defects into multiple levels by quantitatively evaluating the defects based on the image processed data using the machine learning results.

[0214] Furthermore, the defect determination process and the quantitative evaluation process do not need to be performed separately. The control unit 21 can perform defect determination process and quantitative evaluation process together using the result of machine learning using the image processed data as input data and the combination of the type and level of defects evaluated by humans as output data.

[0215] The computer-readable medium storing the program for executing each process is not limited to the above-mentioned example, and a portable recording medium can also be applied. In addition, as a medium for providing program data via a communication line, a carrier wave (carrier frequency) can also be applied.

[0216] Description of Reference Numerals

[0217] 10 film inspection device; 11 light source; 12 camera; 20 information processing device; 21 control unit; 25 display unit; 26 operation unit; 27 storage unit; 28 timing unit; 29 film size measuring unit; 48 reflection prevention plate; 51 captured image; 52 film roll; 53 winding shaft; 54 inspection area; 56 cut out upper position; 57 cut out lower position; 58, 59 cut out width positions; 251 inspection result screen; F film.

Claims

1. A thin film inspection device for optically inspecting defects occurring in thin films in an overlapped state, comprising: a light source, irradiating light toward the film; an optical sensor that detects at least diffuse light among the light reflected in the film; an inspection region extraction unit that extracts an inspection region at an inspection timing from first image data obtained from an output signal of the optical sensor; and The defect detection unit detects the defect by performing data processing on the second image data corresponding to the inspection area.

2. The thin film inspection device according to claim 1, wherein: having a plurality of the optical sensors, The inspection region extraction unit further removes overlapping ranges of the plurality of first image data obtained from each of the plurality of optical sensors.

3. The thin film inspection device according to claim 1 or 2, wherein: The inspection region extraction unit performs processing therein by optical calculation using the size information of the film at the inspection timing and the setting information of the optical sensor.

4. The thin film inspection device according to claim 1 or 2, wherein: The film is wound into a roll. The thin film inspection device inspects the defects generated during the winding of the film.

5. The thin film inspection device according to claim 1 or 2, wherein: The optical sensor is an area sensor.

6. The thin film inspection device according to claim 1 or 2, wherein: A reflection prevention plate is provided so that regular reflected light among the light reflected in the inspection area of ​​the film does not enter the optical sensor. The reflection preventing plate is formed of a diffusion plate.

7. The thin film inspection device according to claim 1 or 2, wherein: A display control unit is provided for causing a display unit to display information on the inspection area extracted by the inspection area extraction unit and / or the defect detected by the defect detection unit.

8. A thin film inspection method for optically inspecting defects generated in thin films in an overlapped state, comprising: a step of irradiating light to the film through a light source; The step of detecting at least diffuse light among the light reflected in the film by an optical sensor; an inspection region extraction step of extracting, by an inspection region extraction unit, an inspection region at an inspection timing from first image data obtained from an output signal of the optical sensor; as well as In the defect detection step, the defect detection unit performs data processing on the second image data corresponding to the inspection area, thereby detecting the defect.

9. The thin film inspection method according to claim 8, wherein: There are a plurality of said optical sensors, In the inspection region extraction step, overlapping ranges of the plurality of first image data obtained from each of the plurality of optical sensors are removed.

10. The thin film inspection method according to claim 8 or 9, wherein: In the inspection region extraction step, processing in the inspection region extraction step is performed by optical calculation using the size information of the film at the inspection timing and the setting information of the optical sensor.

11. The thin film inspection method according to claim 8 or 9, wherein: The film is wound into a roll. In the film inspection method, the defects generated during the winding of the film are taken as the inspection object.

12. The thin film inspection method according to claim 8 or 9, wherein: The optical sensor is an area sensor.

13. The thin film inspection method according to claim 8 or 9, wherein: A reflection prevention plate is provided so that regular reflected light among the light reflected in the inspection region of the thin film does not enter the optical sensor, and the reflection prevention plate is composed of a diffusion plate.

14. The thin film inspection method according to claim 8 or 9, wherein: The method includes a display control step of causing a display unit to display information on the inspection area extracted in the inspection area extraction step and / or the defect detected in the defect detection step.

15. A procedure, A computer of the thin film inspection device for optically inspecting defects generated in the thin film functions as an inspection region extraction unit and a defect detection unit, wherein: The thin film inspection device includes: a light source for irradiating light to thin films in a stacked state; and an optical sensor for detecting at least diffuse light among the light reflected by the thin films. The inspection region extraction unit extracts the inspection region at the inspection timing from the first image data obtained from the output signal of the optical sensor. The defect detection unit detects the defect by performing data processing on the second image data corresponding to the inspection area.

16. The program according to claim 15, wherein: The thin film inspection device includes a plurality of the optical sensors. The inspection region extraction unit further removes overlapping ranges of the plurality of first image data obtained from each of the plurality of optical sensors.

17. The program according to claim 15 or 16, wherein: The inspection region extraction unit performs processing therein by optical calculation using the size information of the film at the inspection timing and the setting information of the optical sensor.

18. The program according to claim 15 or 16, wherein: The film is wound into a roll. The film inspection device inspects the defect generated during the winding of the film.

19. The program according to claim 15 or 16, wherein: The optical sensor is an area sensor.

20. The program according to claim 15 or 16, wherein: The film inspection device is provided with a reflection prevention plate so that regular reflected light among the light reflected in the inspection area of ​​the film does not enter the optical sensor. The reflection prevention plate is formed of a diffusion plate.

21. The program according to claim 15 or 16, wherein: The computer is caused to function as a display control unit that causes a display unit to display information on the inspection area extracted by the inspection area extraction unit and / or the defect detected by the defect detection unit.

Images