JP2002031602A - Apparatus and method for inspecting defect - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus and a method for inspecting defects whereby a position of a joint part of an inspection object detected by a joint part- detecting means can be easily grasped in a transfer line where a storing means for storing the inspection object is set. SOLUTION: Image signals of the inspection object 2 are obtained by a line sensor 4 set to the lower stream side than a looper 10, and defect information is obtained from the image signals by an image processor 5. After the joint part is detected by the joint part detector 6 at the upper stream side than the looper 10, a length D of the object 2 from the joint part detector 6 to the line sensor 4 is computed by a sequencer 7 on the basis of a storage amount of the looper 10. A movement distance M of the joint part is computed by the sequencer 7 on the basis of a movement velocity of the object 2 at the side of an exit of the looper 10. When M>=D is held, defect information to be recorded in a control computer 8 is recorded distinctively from the defect information up to the time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a defect inspection apparatus for detecting defects such as flaws and stains, which is particularly suitably used for a band-like inspection object such as a metal plate, a metal plate, a film, a nonwoven fabric, and a resin plate. The present invention relates to a defect inspection method.

[0002]

2. Description of the Related Art Conventionally, metal plates, films, nonwoven fabrics,
2. Description of the Related Art There is known an apparatus for detecting defects such as flaws, dirt, and spots on the surface of a belt-like inspection object such as a resin plate. As this defect inspection apparatus, for example, light is irradiated to the surface of the inspection object, and the reflected light or transmitted light is captured as an image signal by a line sensor using a CCD camera or the like, and the image is processed by an image processing apparatus. Some of them detect a defect from a change in signal luminance.

In a line for continuously producing an inspection object, for example, a strip-shaped metal plate, as shown in FIG. 4, the end of the inspection object 2 and the beginning of the next inspection object 2 ′ are joined at a joint 51.
Welded in. A hole 52 is formed in the inspection object 2 on the line traveling direction side with respect to the joint 51 in order to grasp the position of the joint 51 on the transport line.
2 is detected by optical means provided at a WP (work point) somewhere on the transport line,
A method of detecting the joint 51 is employed. Hereinafter, the optical means for detecting the hole 52 is referred to as a joint detection device.

[0004] The defect inspection apparatus may be configured to change the position of the joint 51 between the position where the joint detecting device detects the joint 51 and the position where the line sensor obtains an image signal.
By grasping this, the joint 51 is used as a mark for switching when moving to the inspection of the next inspection object 2 ′. Further, the defect inspection apparatus has many defects such as flaws attached during welding work, and sets several m before and after the joint portion 51, which is a part cut and discarded at the time of coil winding, as an invalid range 53. Defect detection has been suspended.

[0005] FIG. 5 shows a schematic diagram for product inspection and shipping adjustment.
FIG. 3 is a diagram showing a positional relationship between a joint detection device 6 and a line sensor 4 in a transport line provided with a looper 10 for temporarily storing the inspection object 2 and adjusting the speed of the transport line before and after the inspection object 2. (A) is an example in which the joint detecting means 6 and the line sensor 4 are installed behind (downstream) the transport line with respect to the looper 10, and (b) is in front (upstream) of the transport line with respect to the looper 10. (C) shows an example in which the joint detection means 6 and the line sensor 4 are installed.
Is an example in which the joint detecting means 6 is provided in front of the transfer line with respect to the looper 10, and the line sensor 4 is provided behind the transfer line with respect to the looper 10.

The looper 10, as shown in FIG. 6, is composed of a combination of a plurality of rollers 61, 62, 63, 64, 65, and moves the rollers 63 up and down to change the interval between these rollers. This is a device that varies the storage distance of the belt-shaped inspection target 2 according to the following. This looper 10
During the operation of, the line speed on the exit side (or the entrance side) of the looper 10, that is, the moving speed of the inspection object 2 is not constant. For example, when the speed of the transport line on the entrance side of the looper 10 is faster than the speed of the transport line on the exit side of the looper 10, the storage amount of the inspection target 2 in the looper 10 increases. In the opposite case, the storage amount of the inspection object 2 in the looper 10 decreases.

[0007]

In such a transport line, it is desirable that the distance between the joint detecting means 6 and the line sensor 4 is sufficiently large. That is, a predetermined range around the joint 51 detected by the joint detecting means 6 is set as an invalid range 53, and the inspection of the inspection target 2 within the invalid range 53 is temporarily stopped. Before the head of the invalid range 53 arrives at the obtained position,
The joint 51 must be detected by the joint detecting means 6. Therefore, the distance between the joint detection unit 6 and the line sensor 4 needs to be at least １ ／ or more of the length of the invalid area 53.

However, even if an attempt is made to ensure a sufficient space between the joint detecting means 6 and the line sensor 4, the joint detecting means 6 and the line sensor 4 are not arranged as shown in FIG. In the case where the installation can be performed only in the positional relationship of (c), since the looper 10 capable of changing the length of the inspection object 2 exists between the joint detection means 6 and the line sensor 4, the joint detection is performed. Means 6
It is difficult to ascertain the position of the joint 51 that is detected by and passes through the looper 10. Therefore, when the positional relationship between the joint detecting means 6 and the line sensor 4 is as shown in FIG. 5C, the position of the joint 51 detected by the joint detecting means 6 and passing through the looper 10 is determined. It has been an issue to be able to grasp with a defect inspection device.

Accordingly, an object of the present invention is to provide a light receiving unit which detects an image signal from a position where a joint detecting unit detects a joint of an inspection object in a transport line provided with a storage unit for storing the inspection object. The position of the joint between the positions where the image signal is obtained can be easily grasped. When the joint arrives at the position where the light receiving means is obtaining the image signal, the next inspection object is inspected. It is an object of the present invention to provide a defect inspection apparatus and a defect inspection method which can be shifted to the above.

[0010]

A defect inspection apparatus according to the present invention is a defect inspection apparatus for inspecting a strip-shaped inspection object moving in a predetermined direction on a transport line provided with a storage means for storing the inspection object. A light receiving means for receiving light from the inspection object moving on the transport line behind the storage line than the storage means and obtaining an image signal thereof; and Image processing means for acquiring defect information from an image signal, joint detecting means for detecting a joint between the end of the inspection object and the beginning of the next inspection object ahead of the storage means, and storage means Based on the storage amount data of the inspection object from the, the length D of the inspection object from the position where the joint detecting means is detecting the joint to the position where the light receiving means is obtaining an image signal, At least the outlet side of the storage means The moving distance M of the joint from the position where the joint is detected by the joint detecting means is calculated based on the moving speed of the object to be inspected, and the moving distance M of the joint is the length D of the inspection object. In the above case, there is provided a data processing unit for recording the defect information of the inspection object acquired by the image processing unit thereafter, separately from the defect information so far.

Further, the data processing means may further include a defect information in the image processing means while an inspection object in a predetermined range before and after the joint exists at a position where the light receiving means obtains an image signal. It is desirable to interrupt the acquisition of the information. Further, it is preferable that the data processing means further updates the inspection standard of the inspection object stored in the image processing unit to the inspection standard of the next inspection object.

Further, the defect inspection method according to the present invention is a defect inspection method for inspecting a belt-shaped inspection object moving in a fixed direction on a transport line provided with a storage means for storing the inspection object. Receiving light from the inspection object moving on the transport line behind the transport line to obtain an image signal thereof; and acquiring defect information from the image signal based on an inspection standard of the inspection object. And detecting the joint between the end of the inspection object and the beginning of the next inspection object ahead of the storage means on the transport line, based on the storage amount data of the inspection object in the storage means,
Calculating the length D of the inspection object from the position where the joint is detected to the position where the image signal of the inspection object is obtained, and the moving speed of the inspection object at least on the exit side of the storage means. Calculating the moving distance M of the joint from the position where the joint is detected, and acquiring the moving distance M of the joint when the moving distance M becomes longer than the length D of the inspection object. And recording the detected defect information of the inspection object separately from the previous defect information.

Further, the defect inspection method of the present invention further comprises:
It is desirable to include a step of interrupting the step of obtaining defect information from the image signal while the inspection object in a predetermined range before and after the joint exists at the position where the image signal of the inspection object is obtained. Further, in the defect inspection method of the present invention, furthermore, the moving distance M of the joint is the length D
In the case described above, it is desirable to have a step of updating the inspection standard of the inspection object to the inspection standard of the next inspection object.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
FIG. 1 is a block diagram showing an example of the defect inspection apparatus of the present invention. The defect inspection apparatus 1 includes an illuminating device 3 that irradiates light on the surface of an inspection object 2 that moves in a predetermined direction along a transport line behind a looper 10, and receives light from the inspection object 2 to generate an image of the illumination device 3. A line sensor 4 (light receiving means) for obtaining a signal, an image processing device 5 (image processing means) for processing this image signal, and a joint detecting device 6 (for detecting a joint of the inspection object 2 in front of the looper 10) It is schematically configured to include a joint detecting means), a sequencer 7 (data processing means) for processing various data and signals, and a control computer 8 (data processing means) for controlling the entire apparatus.

The inspection object 2 is made of a long, band-shaped metal plate, film, cloth, nonwoven fabric, resin plate, or the like, and moves on a transport line so as to be perpendicular to the length direction of the line sensor 4. ing. For the defect inspection using the defect inspection apparatus 1, a metal plate such as a steel plate, a plated steel plate, a pickled steel plate, a coated steel plate, a copper plate, and an aluminum plate is suitably used.

The illuminating device 3 is a linear illuminating device arranged such that the longitudinal direction of the light irradiation range on the inspection object 2 is orthogonal to the moving direction of the inspection object 2. Rod illumination, optical fiber illumination, and the like. In the illustrated example, the illumination device 3 is arranged on the same surface side of the inspection target 2 as the line sensor 4, but the arrangement of the illumination device in the present invention is not limited to this. For example, the illumination device may be arranged on the back side of the inspection target 2 opposite to the line sensor 4, irradiate light from the back of the inspection target 2, and receive the transmitted light by the line sensor 4.

The line sensor 4 is a line-shaped optical sensor arranged so that the longitudinal direction of the imaging range is orthogonal to the moving direction of the inspection object 2, and receives the reflected light from the inspection object 2 and performs inspection. It outputs an image signal corresponding to the light intensity distribution on the surface of the inspection object 2 in units of lines (inspection lines) orthogonal to the moving direction of the object 2. As the line sensor 4, for example, the number of elements (the number of pixels) is 2048 or 50.
00 CCD camera or the like is used.

The image processing device 5 processes the image signal output from the line sensor 4 in accordance with a predetermined program, detects a defect existing in the inspection object 2, and transmits the detected defect information to the control computer 8. Is output to As the image processing device 5, a known image processing device used in a defect inspection device can be used.

FIG. 2 is a block diagram showing an example of the configuration of the image processing device 5. The image processing device 5 includes an A / D conversion unit 21 that converts an image signal from an analog signal to a digital signal, a binarization unit 22 that binarizes a digital signal according to a set threshold, and a binarization unit. A run-length encoding unit 23 for run-length encoding the digital signal; and a connectivity processing unit 2 for joining the run-length encoded image signal for each inspection line in the moving direction of the inspection object 2
4 and inspection criteria for the inspection object 2 (threshold, defect size, etc.)
And a storage unit 25 for storing the information.

The A / D converter 21 outputs an image signal Ai (i: pixel No) for each pixel output from the line sensor 4.
Is converted into a digital signal Bi representing, for example, an 8-bit density value (256 gradations). Binarization unit 22
Is for binarizing the digital signal Bi converted by the A / D converter 21 in accordance with the threshold value Di stored in the storage unit 25. For example, when trying to detect a defect (bright defect) brighter than the normal part, the binarization unit 22 converts the binarized digital signal Bi ′ to “1” when the digital signal Bi is equal to or larger than the threshold Di. And the digital signal Bi is equal to the threshold D
If it is less than i, the digital signal Bi 'after binarization is set to "0". The binarization unit 22 may be configured to detect a defect (dark defect) darker than the normal part.
Here, the threshold value Di is a boundary value that determines a portion of the digital signal Bi having a density difference (unit%) as compared with a normal portion to be detected as a defective portion.

The run-length encoding section 23 compresses the digital signal after binarization in order to further reduce the memory capacity. The connectivity processing unit 24 joins the compressed image signals for each inspection line in the moving direction of the inspection object 2, and compares the compressed image signal with the defect size that exists in the inspection object 2 and is stored in the storage unit 25. A large defect is detected, the area of the detected defect, the length of the inspection object 2 in the moving direction, the length of the inspection object 2 in the width direction, the center position (defect position) in the width direction, the rank (large or small), This is for acquiring defect information such as the type.

The joint detecting device 6 detects a hole formed in the vicinity of the joint of the inspection object 2 by optical means using a WP (work point). As the joint detecting device 6, a known joint detecting device used for a defect inspection device, for example, a laser sensor, an area CCD sensor, or the like can be used.

The sequencer 7 is based on the stored amount data 30 of the inspection object 2 in the looper 10 and the exit side moving speed 32 of the inspection object 2 detected by the exit length meter 12 provided on the exit side of the looper 10. The position of the joint detected by the joint detecting device 6 is grasped at any time. As the sequencer 7, a known sequencer used in a defect inspection apparatus can be used.

Specifically, the sequencer 7 includes a looper 10
From the position at which the joint detection device 6 detects the joint to the position at which the line sensor 4 obtains image information, based on the stored amount data 30 of the test object 2 from FIG.
Of the inspection object 2 on the exit side of the looper 10
The moving distance M of the joint from the position where the joint detecting device 6 detects the joint is calculated based on the outgoing side moving speed 32 of the joint, and the moving distance M of the joint and the length of the inspection object 2 are calculated. When D satisfies a specific relationship described later, an inspection management signal 37 is output to the control computer 8.

Here, the output side length meter 12 is used for the inspection object 2.
Is a device that measures the moving distance of the object and outputs a length measurement pulse (for example, a signal of 10 mm / pulse) every time the inspection object 2 moves a predetermined distance. The moving speed of the inspection target 2 can be calculated from the interval at which the length measuring pulse is output from the exit length measuring device 12.

In the present invention, the outgoing side moving speed 3
Since the movement distance M of the joint can be ascertained from 2, the data of the entry-side movement speed is not necessarily required. However, in order to accurately grasp the moving distance of the joint between the position where the joint detecting device 6 detects the joint and the entrance of the looper 10, the sequencer 7 needs to be positioned at the entrance of the looper 10. It is desirable to calculate the moving distance M of the joint on the entrance side of the looper 10 based on the entrance side moving speed 31 from the side length meter 11. In addition, storage amount data 3
When 0 cannot be obtained by the sequencer 7, the movement distance (storage amount data) in the entrance length meter 11 to the looper 10 on the entrance side of the looper 10 can be calculated.

The control computer 8 controls the defect inspection apparatus 1, records defect information from the image processing apparatus 5, processes defect information from the image processing apparatus 5, outputs defect information to the outside, and controls the image processing apparatus 5. The inspection criteria used (threshold Di,
This is an apparatus for setting a defect size and the like. FIG.
FIG. 3 is a block diagram illustrating an example of a configuration of a control computer 8. The control computer 7 is schematically configured including a storage unit 41, a processing unit 42, and an interface unit (I / F unit) 43.

The storage section 41 mainly stores defect information from the image processing apparatus 5. Note that the storage unit 42
It is composed of a volatile memory such as a RAM (Random Access Memory), a nonvolatile memory such as a hard disk device, a magneto-optical disk device, a flash memory, or a combination thereof.

The processing unit 42 distinguishes the defect information of the inspection object 2 acquired by the image processing device 5 from the defect information obtained up to that point, after the reception of the joint arrival signal 37 from the sequencer 7. Is recorded. Further, the processing unit 42 interrupts the acquisition of the defect information by the image processing device 5 while the invalid range of the inspection object 2 exists at the position where the line sensor 4 obtains the image signal. In addition,
When the position where the line sensor 4 obtains the image signal is far away from the front surface position and the back surface position, it is necessary to include this distance in the invalid range.

When the processing unit 42 receives the inspection management signal 37 from the sequencer 7, the processing unit 42 changes the inspection standard of the inspection object 2 stored in the storage unit 25 of the image processing apparatus 5 to the next inspection object 2. 'Is updated to the inspection standard. This inspection criterion may be transmitted from a higher-level computer connected to the control computer 8 by communication means such as serial communication or Ethernet (registered trademark). Processing unit 4
Numeral 2 converts the defect information stored in the storage unit 41 into an output format to an external monitor, printer, or the like, and outputs the format to the outside.

The processing section 42 may be realized by dedicated hardware. The processing section 42 is constituted by a memory and a central processing unit (CPU). The function may be realized by loading a program for realization into a memory and executing the program.

The interface unit (I / F unit) 43
The communication is performed between the image processing apparatus 5, the sequencer 7, the peripheral devices, and the processing unit 42. As the interface unit 43, for example, a general-purpose interface bus (GPIB) is used. Further, it is assumed that an input device, a display device, and the like are connected to the control computer 8 as peripheral devices. Here, the input device refers to an input device such as a display touch panel, a switch panel, and a keyboard, and the display device is a CRT.
And a liquid crystal display device.

In this embodiment, the calculation of the length D of the inspection object 2 from the position at which the joint detection device 6 detects the joint to the position at which the line sensor 4 obtains image information, Although the sequencer 7 calculates the moving distance M of the joint from the position where the joint detecting device 6 detects the joint, the defect inspection apparatus of the present invention is not limited to this example. Instead, these operations may be performed by the processing unit 42 in the control computer 8.

In such a defect inspection apparatus 1, the line sensor 4 detects the position where the joint detection device 6 detects the joint based on the storage amount data 30 from the variable storage amount looper 10. The joint detection unit 6 calculates the length D of the inspection object 2 up to the position where the image signal is obtained, and based on the exit side moving speed 30 of the inspection object 2 on the exit side of the looper 10, Since the sequencer 7 for calculating the moving distance M of the joint from the position where the part is detected is provided,
In the transfer line provided with the looper 10, the position of the joint between the position where the joint detecting device 6 detects the joint and the position where the line sensor 4 obtains the image signal can be easily grasped. be able to.

The processing section 42 of the control computer 8
Is to interrupt the acquisition of the defect information in the image processing device 5 while the invalid range of the inspection object exists at the position where the line sensor 4 is obtaining the image signal. Labor saving. Further, when the processing unit 42 receives the inspection management signal 37 from the sequencer 7, the inspection standard of the inspection target 2 stored in the storage unit 25 of the image processing apparatus 5 is changed to the inspection standard of the next inspection target 2 ′. , It is possible to continuously inspect different inspection objects such as surface conditions, types, materials, and inspection standards for each user.

Next, the operation of the defect inspection apparatus 1 will be described. The light emitted from the illumination device 3 to the surface of the inspection target 2 at the detection position and reflected by the surface of the inspection target 2 is received by the line sensor 4. The light received by the line sensor 4 is output to the image processing device 5 as an image signal.

An analog image signal Ai (i: pixel No) for each pixel output from the line sensor 4 is converted into an 8-bit density value (256 gradations) by the A / D converter 21 in the image processing device 5. Into a digital signal Bi.
The digital signal Bi converted by the A / D converter 21 is input from the control computer 8, set, and binarized by the binarizer 22 in accordance with the threshold Di stored in the storage 25. The digital signal after binarization is run-length encoded by the run-length encoding unit 23. The image signal for each test line that has been run-length coded is connected to the connectivity processing unit 2.
At 4, the inspection objects 2 are joined in the moving direction. From the combined image signals, defects that are input and set from the control computer 8 and are equal to or larger than the inspection criterion (size) stored in the storage unit 25 are detected.
Defect information such as the length of the inspection object 2 in the moving direction, the length of the inspection object 2 in the width direction, the center position (defect position) in the width direction, the rank (large or small), and the type is acquired. The defect information thus obtained by the image processing device 5 is stored in the storage unit 41 of the control computer 8.

When the sequencer 7 receives the joint detection signal 36 output from the joint detector 6 by detecting the joint of the inspection object 2 by the joint detector 6,
The sequencer 7 detects the position where the joint detection device 6 detects the joint by using the following (formula 1) based on the exit moving speed 32 (length measurement pulse) from the exit length measuring instrument 12 of the looper 10. Of the joint moving distance M (hereinafter referred to as joint moving distance M) from the joint and the stored amount data 30 from the looper 10, the joint detecting device 6 using the following (Equation 2) The calculation of the length LD of the inspection object 2 from the position where the part is detected to the looper 10 (hereinafter referred to as the looper length LD) is started. (Equation 1) M (m) = Length measurement pulse (pulse) on the exit side of looper × Pulse resolution (m / pulse) (Equation 2) LD (m) = Storage amount data (%) × Maximum storage amount of looper (m ) + ID Here, the ID in the expression is the inspection object 2 from the position where the joint detection device 6 detects the joint to the entrance of the looper 10.
Is a fixed length (m).

The sequencer 7 reads out the outgoing movement speed 32 (length measuring pulse) from the outgoing length measuring meter 12 at any time, adds the read out moving speed 32, and calculates the joint moving distance M. When the storage amount data 30 from the looper 10 changes, the looper inner length LD is recalculated based on the storage amount data 30. Looper length LD and looper 10
From the exit of the inspection object 2 to the position where the line sensor 4 obtains the image signal (hereinafter referred to as the looper exit side length OD).
), The joint moving distance M, and the invalid range NM (m).
Satisfies the relationship of the following (Equation 3), that is,
The head of the invalid area NM of the inspection object 2 is the line sensor 4
Arrives at the position where the image signal is obtained, the sequencer 7 outputs to the control computer 8 an inspection management signal 37 for stopping the defect inspection of the inspection object. (Equation 3) 0 ≧ (LD + OD−NM / 2) −M

The control computer 8 which has received the inspection management signal 37 for stopping the defect inspection stops the acquisition of the defect information in the image processing apparatus 5. Also, when the relationship of the above (Equation 3) is established, the sequencer 7 initializes the joint moving distance M to 0, and sets the outlet moving speed 32 from the outlet measuring meter 12 to 32.
Based on the (length measurement pulse), the calculation of the joint moving distance M using the following (Equation 3) is restarted. Then, when the joint moving distance M and the invalid range NM satisfy the relationship of the following (Equation 4), that is, the invalid range NM of the inspection object 2 is:
When the line sensor 4 has completely passed the position where the image signal is obtained, the sequencer 7 outputs to the control computer 8 an inspection management signal 37 for restarting the defect inspection of the inspection object 2. (Equation 4) 0 ≧ NM−M

After the control computer 8 receives the inspection management signal 37 from the sequencer 7, the defect information of the inspection object 2 'obtained by the image processing apparatus 5 is different from the defect information of the inspection object 2 up to that time. Separately, it is recorded in the storage section 41 of the control computer. Also, between the reception of the inspection management signal 37 for stopping the defect inspection and the reception of the inspection management signal 37 for restarting the defect inspection, the information is stored in the storage unit 25 of the image processing apparatus 5 as necessary. The inspection standard of the inspection object 2 is updated by the control computer 8 to the inspection standard of the next inspection object 2 ′.

In this embodiment, the output side moving speed 3
2 is obtained as a length measurement pulse from the output side length meter 12, but is not limited to this in the present invention.
As will be described later, data of the moving speed obtained by converting the voltage (0 to 10 V) measured by the line speed detecting means into a digital value (0 to 255 bits) may be obtained.

An entrance length measuring instrument 11 is provided at the entrance side of the looper 10.
Is installed, and based on the entry-side moving speed 31 from the entry-side length meter 11, the junction movement distance IM on the entry side of the looper 10 is calculated until the relationship of the following (Equation 5) is satisfied, that is, the junction This IM may be used instead of M while the joint exists between the position where the detection device 6 detects the joint and the entrance of the looper 10. (Equation 5) 0 ≧ ID-IM As described above, the entry side movement speed 31 and the exit side movement speed 32
By calculating the joint moving distance M based on both data, the joint moving distance M from the position where the joint detecting device 6 detects the joint can be more accurately grasped. become.

In such a defect inspection method, based on the storage amount data 30 from the variable storage amount looper 10, the line sensor 4 detects an image from the position where the joint detection device 6 detects the joint. The joint detection device calculates the length D (= LD + OD) of the inspection object 2 up to the position where the information is obtained, and based on the exit side moving speed 32 of the inspection object 2 at the exit side of the looper 10. 6 calculates the moving distance M of the joint from the position where the joint is detected.
0 in the transfer line provided with the
The position of the joint between the position where the joint is detected and the position where the line sensor 4 obtains the image signal can be easily grasped, and the position where the line sensor 4 obtains the image signal. When the joint arrives at the next inspection object 2 ', inspection can be performed.

Further, the step of interrupting the step of acquiring defect information from the image signal while the inspection object within a predetermined range before and after the joint is present at the position where the image signal of the inspection object is obtained. Therefore, labor saving such as printout of defect information can be achieved. Further, when moving to the inspection of the next inspection object 2 ′, the inspection standard of the inspection object 2 stored in the storage unit 25 of the image processing device 5 is updated to the inspection standard of the next inspection object 2 ′. Thereby, it is possible to continuously inspect different inspection objects such as surface conditions, types, materials, and inspection standards for each user. Further, according to such a defect detection method, even if a plurality of joints (holes) detected by the joint detecting device 6 are present in the looper 10 at the same time, the positions of the joints can be easily grasped. Can be.

[0046]

Embodiments Hereinafter, specific embodiments will be described. The length (ID) of the inspection object 2 from the position where the joint detection device 6 detects the joint to the entrance of the looper 10 is 4.3.
m, and the length of the inspection object 2 in the looper 10 is 0 to 5
02m, which is variable between 0 m and 2 m, and the inspection object 2 from the exit of the looper 10 to the position where the line sensor 4 obtains an image signal.
Inspection device 1 shown in FIGS. 1 to 3 for defect inspection of a cold rolled steel plate having a width of 1650 mm in a line having a length of 0 m.
This was performed using

[Devices and Settings] As the lighting device 3,
A 110 W lamp manufactured by Kyoto Electric Co., Ltd. was used. As the line sensor 4, an SCD-2048-pixel having 2048 pixels is used.
20 (manufactured by Mitsubishi Rayon Co., Ltd., CCD camera) were prepared, and used in a configuration in which these were arranged in the width direction of the inspection object 2. At this time, the resolution in the width direction of the line sensor 4 was 0.5 mm / pixel, and the resolution in the traveling direction was 0.5 mm / scan. As the image processing device 5, LSC-300 manufactured by Mitsubishi Rayon Co., Ltd. was used. FX2NC of Mitsubishi Electric Corporation was used as the sequencer 7. Further, the sequencer 7 has an A / D for converting an analog voltage into a digital signal.
The D extension unit FX0N-3A was attached.

The image signal output from the line sensor 4 is set to be digitized in 8 bits by the A / D converter 21 of the image processing device 5. The invalid range NM before and after the joint is set to 20 m.

The exit moving speed 32 was measured as a voltage of 0 to 10 V at the exit of the looper 10. That is, a voltage of 10 V was measured at the maximum speed of 250 m / min. This voltage was subjected to A / D conversion so that the maximum voltage of 10 V became a digital value of 255 bits, and then input to the sequencer 7. Outgoing side moving speed 32 100mse
When the sequencer 7 is set to read at c intervals,
Since the inspection object 2 moving at the maximum speed moves 416.7 mm in 100 msec, the inspection object 2 moves 100 msec.
1 after A / D conversion when reading at intervals of sec
The amount of movement per bit is 1.6341 (mm / bit)
It was calculated.

The stored data 30 of the inspection object 2 in the looper 10 was measured as a voltage of 0 to 5V.
That is, a voltage of 5 V was measured when the maximum storage amount was 502 m. The maximum voltage of 5 V is 25
After being A / D converted to be a 5-bit digital value, it was input to the sequencer 7. Here, the storage amount per bit was calculated to be 1.968 (m / bit).

[Implementation of Defect Inspection] First, moving speed 0 to 2
From the inspection object 2 moving at 50 m / min to the line sensor 4
The image signal obtained in the above is converted into an A / D
Transformation, binarization, run-length encoding, and connectivity processing were performed to detect a defect on the inspection object 2, and to acquire defect information. The obtained defect information was stored in the storage unit 41 of the control computer 8.

A pulse signal of 100 msec output from the joint detection device 6 by the joint detection device 6 detecting the joint of the inspection object 2 (the joint detection signal 36).
Is received by the sequencer 7, thereafter, the outgoing side moving speed 32 (bits) is changed at intervals of 100 msec.
, And this bit value was added in the sequencer 7. And the joint moving distance M is
In the sequencer 7, the calculation is performed by multiplying the value obtained by the bit addition by 1.6341 (mm / bit).

When a 100 msec pulse signal (junction detection signal 36) is received by the sequencer 7, the length LD inside the looper is equal to the length of the looper 1 read by the sequencer 7.
It was calculated by the sequencer 7 based on the stored amount data 30 at 0. At this time, the voltage measured by the looper 10 is 2.5 V, and the A / D converted bit value is 12 V.
Since it was 7 bits, the length LD inside the looper was 127
(Bit) × 1.968 (m / bit) + ID = 249
+4.3 (m).

Looper length LD (= 249 + 4.3 m)
When the looper exit side length OD (= 0 m), the joint moving distance M (m), and the invalid range NM (= 20 m) satisfy the relationship of the following (formula 3), the control computer 8 is notified. An inspection management signal 37 for stopping the defect inspection of the inspection object is output from the sequencer 7. (Equation 3) 0 ≧ (LD + OD−NM / 2) −M = (249 + 4.3 + 0−20 / 2) −M

When the control computer 8 receives the inspection management signal 37 for stopping the defect inspection, the acquisition of the defect information in the image processing apparatus 5 is interrupted by the control computer 8. Further, when the relationship of (Equation 3) was established, the joint moving distance M was initialized to 0 by the sequencer 7. Thereafter, the joint moving distance M is set to 100 msec.
It was read at c intervals and computed by the sequencer 7 based on the bit-added value.

The joint moving distance M and the invalid range NM (= 2
0m) satisfies the following expression (Equation 4), the sequencer 7 outputs an inspection management signal 37 to the control computer 8 to restart the defect inspection of the inspection object. (Equation 4) 0 ≧ NM−M = 20−M The control computer 8 sends the inspection management signal 3 from the sequencer 7
7, the defect information of the inspection object 2 ′ acquired by the image processing device 5 is recorded in the storage unit 41 of the control computer, distinguished from the defect information of the inspection object 2 up to that time.

[0057]

As described above, the defect inspection apparatus according to the present invention receives light from an inspection object moving on a transport line behind the transport line with respect to the storage means, and obtains an image signal thereof. Means, image processing means for acquiring defect information from an image signal from the light receiving means based on the inspection standard of the inspection object, and the end of the inspection object and the next inspection object in front of the transport line relative to the storage means A light-receiving means for detecting an image signal from a position at which the joint detecting means detects a joint based on data on the amount of storage of the inspection object from the storage means; The length D of the inspection object up to the obtained position is calculated, and based on the moving speed of the inspection object at least on the exit side of the storage means, the position from the position where the joint detection means detects the joint is calculated. Calculate the moving distance M of the joint, Data processing means for, when the moving distance M of the section becomes equal to or greater than the length D of the inspection object, discriminating the defect information of the inspection object acquired by the image processing means thereafter from the previous defect information Therefore, it is possible to easily grasp the position of the joint between the position where the joint detecting means detects the joint of the inspection object and the position where the light receiving means obtains the image signal. When the joint arrives at the position where the light receiving means obtains the image signal, the inspection can be shifted to the next inspection object.

In addition, the data processing means further includes, while the inspection object within a predetermined range before and after the joint exists at the position where the light receiving means obtains the image signal, the defect information in the image processing means. If the acquisition of the defect information is interrupted, labor saving such as printing out the defect information can be achieved. Further, the data processing means may further update the inspection standard of the inspection object stored in the image processing unit to the inspection standard of the next inspection object, if the surface state, the kind, the material, the color, etc. Can be inspected successively.

Further, the defect inspection method of the present invention is a defect inspection method for inspecting a strip-shaped inspection object moving in a predetermined direction on a transport line provided with a storage means for storing the inspection object. Receiving light from the inspection object moving on the transport line behind the transport line to obtain an image signal thereof; and acquiring defect information from the image signal based on an inspection standard of the inspection object. And detecting the joint between the end of the inspection object and the beginning of the next inspection object ahead of the storage means on the transport line, based on the storage amount data of the inspection object in the storage means,
Calculating the length D of the inspection object from the position where the joint is detected to the position where the image signal of the inspection object is obtained, and the moving speed of the inspection object at least on the exit side of the storage means. Calculating the moving distance M of the joint from the position where the joint is detected, and acquiring the moving distance M of the joint when the moving distance M becomes longer than the length D of the inspection object. And recording the defect information of the inspected object separately from the defect information up to that point, so that the defect information is located between the position where the joint of the inspected object is detected and the position where the image signal is obtained. The position of the joint can be easily grasped, and when the joint arrives at the position where the image signal is obtained, the inspection can be shifted to the next inspection object.

Further, the defect inspection method of the present invention further comprises:
At the position where the image signal of the inspection object is obtained, while the inspection object in the predetermined range before and after the joint is present, if there is a step of interrupting the step of acquiring the defect information from the image signal In addition, labor saving such as printout of defect information can be achieved. In addition, the defect inspection method of the present invention further comprises the step of:
If there is a step of updating the inspection standard of the inspection object to the inspection standard of the next inspection object, it is possible to continuously inspect the inspection objects having different surface conditions, types, materials, colors, etc. it can.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an example of a defect inspection apparatus according to the present invention.

FIG. 2 is a block diagram illustrating an example of an image processing apparatus used in the defect inspection apparatus according to the present invention.

FIG. 3 is a block diagram showing an example of a control computer used in the defect inspection device of the present invention.

FIG. 4 is a top view showing an example of a connection portion of an inspection object.

FIG. 5 is a schematic diagram showing a positional relationship between a line sensor and a connection detecting device on a transfer line provided with a looper.

FIG. 6 is a schematic diagram illustrating an example of a looper.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Defect inspection apparatus 2 Inspection object 4 Line sensor (light receiving means) 5 Image processing apparatus (image processing means) 7 Sequencer (data processing means) 8 Control computer (data processing means) 10 Looper (storage means) 51 Joining part 53 Invalid range

 ──────────────────────────────────────────────────続 き Continuing on the front page F term (reference) 2F065 AA03 AA15 AA17 AA21 AA22 AA49 AA61 BB13 BB15 CC02 CC06 FF42 GG03 GG08 GG14 GG16 HH15 JJ02 JJ25 LL03 MM03 QQ03 QQ04 QQ23 QQ24 QQ31 AA13 CB02 EB01 EB02 ED08 5B057 AA02 BA12 BA29 CG04 CH18 DA03 DA07 DB02 DB08 DC03 DC04

Claims (6)

[Claims] 1. A defect inspection apparatus for inspecting a strip-shaped inspection object moving in a predetermined direction on a transport line provided with a storage means for storing the inspection object, wherein the defect is transported behind the transport line with respect to the storage means. A light receiving unit that receives light from the inspection object moving along the line and obtains an image signal thereof; and an image processing unit that acquires defect information from the image signal from the light receiving unit based on an inspection standard of the inspection object. A joint detecting means for detecting a joint between the end of the inspection object and the beginning of the next inspection object in front of the transport line with respect to the storage means, and based on the storage amount data of the inspection object from the storage means. ,
The length D of the inspection object from the position where the joint detecting means detects the joint to the position where the light receiving means obtains the image signal.
Based on the moving speed of the inspection object at least on the exit side of the storage means, the moving distance M of the joint from the position where the joint detecting means detects the joint is calculated. When the moving distance M is equal to or longer than the length D of the inspection object, data processing means for separately recording defect information of the inspection object acquired by the image processing means from the previous defect information is provided. A defect inspection device, comprising: 2. The image processing device according to claim 1, wherein said data processing unit further includes a defect information processing unit that detects an image signal in a predetermined range before and after the joint at a position where the light receiving unit obtains an image signal. The defect inspection apparatus according to claim 1, wherein acquisition of the defect is interrupted. 3. The apparatus according to claim 1, wherein said data processing means further updates an inspection standard of the inspection object stored in the image processing unit to an inspection standard of the next inspection object. The defect inspection apparatus according to claim 2. 4. A defect inspection method for inspecting a strip-shaped inspection object moving in a predetermined direction on a transport line provided with a storage means for storing the inspection object, wherein the transportation is performed behind the transportation line with respect to the storage means. Receiving light from the inspection object moving along the line and obtaining an image signal thereof; acquiring defect information from the image signal based on an inspection standard of the inspection object; Detecting the joint between the end of the inspection object and the beginning of the next inspection object in front of the object; and inspecting from the position where the joint is detected based on the storage amount data of the inspection object in the storage means. Calculating the length D of the inspection object up to the position where the image signal of the object is obtained; and detecting the joint based on the moving speed of the inspection object at least on the exit side of the storage means. position Calculating the moving distance M of the joints, and when the moving distance M of the joints becomes equal to or greater than the length D of the inspection object, the defect information of the inspection object acquired after that is obtained. And recording the information separately from the defect information. 5. A step of acquiring defect information from an image signal while an inspection object in a predetermined range before and after a joint exists at a position where an image signal of the inspection object is obtained. The defect inspection method according to claim 4, further comprising a step. 6. The defect inspection method according to claim 4, further comprising the step of updating the inspection standard of the inspection object to the inspection standard of the next inspection object.