JP7019939B2 - Belt inspection device - Google Patents

Description

The present invention relates to a belt inspection device for inspecting the presence or absence of damage to the belt of a belt conveyor.

Conventionally, a belt conveyor has been used for excretion of soil for construction work and civil engineering work. If the belt conveyor is operated intermittently or continuously for a long time, cracks may occur in the belt. In particular, if the earth and sand loaded on the belt contains foreign matter, the foreign matter penetrates the belt and the belt is torn in the traveling direction, resulting in vertical tearing of the belt. In addition, the tension of the belt may cause cracks to grow and the belt to break. Therefore, there is a technique for detecting a crack in the belt by analyzing the captured image of the belt by an image processing technique (see, for example, Patent Document 1).

Hereinafter, the reference numerals used in Patent Document 1 are shown in parentheses, and the techniques described in Patent Document 1 will be described. According to the description of Patent Document 1, by illuminating the belt (1) with the laser oscillator (2), a linear bright portion (10) extending in the width direction of the belt (1) is formed on the lower surface of the belt (1). Then, the lower surface of the belt (1) is imaged by the digital camera (3) so that the linear bright portion (10) is included in the imaging range. In the captured image, the linear image corresponding to the linear bright portion (10) appears with high gradation. When a vertical tear occurs in the belt (1), the linear bright portion (10) is divided, so that a linear image having a high gradation is divided in the image, and a disconnection having a low gradation between them is divided. An image appears. In order to detect the presence or absence of such a disconnection image, the image captured by the digital camera (3) is binarized, then the noise in the binary image is removed, and then the disconnection image is subjected to the labeling process of the binary image. Is detected and recognized.

Japanese Unexamined Patent Publication No. 2007-230706

By the way, when the uneven portion by engraving is formed on the belt, if the technique described in Patent Document 1 is adopted, the shadow of the uneven portion is generated when the uneven portion passes through the illumination range of the laser oscillator (2). , The linear bright part (10) is divided by the shadow. Therefore, even though there are no vertical tears in the belt, the linear image with high gradation in the image is divided, and the shadow of the uneven portion is detected as the broken line image.
Further, when water adheres to the belt, it appears darker than the original color of the belt in the region where the water adheres. Therefore, when the technique described in Patent Document 1 is adopted, the gradation of the portion corresponding to the water adhesion region becomes low in the image when the water adhesion region passes through the illumination range of the laser oscillator (2). A linear image with high gradation is divided. Therefore, even though there is no vertical tear in the belt, the water adhesion region is detected as a disconnection image.

The present invention has been made in view of the above circumstances, and the problem to be solved by the present invention is to prevent erroneous detection of uneven portions on the surface of the belt and water adhesion regions as cracks in the belt. Is.

In order to solve the above problems, the belt inspection device according to the present invention is a belt inspection device that inspects a belt of a belt conveyor, and is imaged by an image pickup device that images a predetermined portion of the belt and the image pickup device. The image is binarized, and the determination unit for determining the presence or absence of a black damaged portion in the binarized image obtained by the binarization faces the image pickup range of the belt by the image pickup device, and the image pickup range is directed toward the image pickup range. A light guide plate type or surface light emitting element type planar light emitting device for irradiating diffused light is provided , and the belt is bridged between a pulley on the upstream side in the transport direction and a pulley on the downstream side in the transport direction. The upper conveyor belt portion in which the image pickup device and the planar light emitting device travel from the upstream pulley to the downstream pulley of the belt, and the upstream pulley from the downstream pulley. A translucent portion is formed in the central portion of the planar light emitting device, which is provided between the lower return belt portion traveling toward the surface and the image pickup device is more from the transport belt portion than the planar light emitting device. Installed separately, the planar light emitting device illuminates the lower surface of the transport belt portion, and the image pickup device images the lower surface of the transport belt portion through the translucent translucent portion.

According to the present invention, when the uneven portion is formed on the belt, the planar light emitting device emits light from a wide range, so that the uneven portion is irradiated with light from a wide range. Therefore, the shadow of the uneven portion is not generated or is thinly generated. Then, when the belt is imaged by the image pickup device so that the uneven portion is included in the imaging range, the shadow of the uneven portion does not appear in the image, or even if it appears, the shadow is thin. Therefore, when the image is binarized by the determination unit and the presence or absence of the black damaged portion in the binary image is determined by the determination unit, it is possible to prevent the uneven portion from being determined as the damaged portion.
Further, when water is attached to the belt, the planar light emitting device emits light from a wide range, so that the water is irradiated from a wide range and easily reflected on the surface of the water. Then, when the belt is imaged with an image pickup device so that the water adhering to the belt is included in the image pickup range, the portion corresponding to the water appears brightly in the image. Therefore, when the image is binarized by the determination unit and the determination unit determines the presence or absence of the black damaged portion in the binary image, it is possible to prevent water from being determined as the damaged portion.

Further , since the light emitted from the planar light emitting device is diffused light, the light is incident on the uneven portion formed on the belt from a wide range. Therefore, the shadow of the uneven portion hardly appears in the image, and it is possible to prevent the uneven portion from being determined as a damaged portion. Similarly, it is possible to prevent the water adhering to the belt from being determined as a damaged portion.

According to the present invention, even if an uneven portion such as an engraved portion is formed on the belt or water adheres to the belt, the uneven portion or water does not appear in the binary image, and the uneven portion or the uneven portion is damaged. It is possible to prevent the determination as a part.

FIG. 1 is a side view showing a belt conveyor and a belt inspection device. FIG. 2 is a schematic cross-sectional view seen in the transport direction of the belt. FIG. 3 is a plan view of the belt. FIG. 4 is a block diagram showing a belt inspection device. FIG. 5 is a drawing showing images before and after binarization processing when a planar light emitting device is used. FIG. 6 is a drawing showing images before and after binarization processing when a planar light emitting device is used. FIG. 7 is a drawing showing images before and after binarization processing when a linear light emitting device is used. FIG. 8 is a perspective view showing a linear light emitter assembly, an image pickup device, and a belt.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, although the embodiments described below are provided with various technically preferable limitations for carrying out the present invention, the scope of the present invention is not limited to the following embodiments and illustrated examples.

1. 1. Belt Conveyor and Belt Inspection Device FIG. 1 is a schematic side view showing the belt conveyor 20 and the belt inspection device 10. FIG. 2 is a schematic cross-sectional view showing a surface along II-II shown in FIG. 1 in the direction of an arrow.

The belt inspection device 10 and the belt conveyor 20 are used during tunnel excavation work. In the tunnel excavation work, the face 2 of the tunnel 1 is excavated using an excavator (not shown) such as a shield machine or a tunnel boring machine, and the earth and sand generated during the excavation of the face 2 is removed by the belt conveyor 20 at the wellhead of the tunnel 1. Transport up to 3. The belt conveyor 20 is operated when excavating the face 2 or when the excavation work is interrupted, but the belt inspection device 10 is used to crack (particularly, longitudinally tear) or break the belt 21 during the operation of the belt conveyor 20. inspect. The vertical tear means a crack extending in the transport direction of the belt 21.

The belt conveyor 20 includes a belt 21, a drive pulley 22, a tail pulley 23, a snap pulley 24, a return roller 25, a carrier roller 26, a motor 27, a scraper 28, and an injector 29. The tail pulley 23 is located at the rear of the excavator, the drive pulley 22 is located at the wellhead 3, and the snap pulley 24 is located closer to the face 2 than the drive pulley 22. The belt 21 is hung on the pulleys 22 and 23, and the return belt portion 21b on the lower side of the pulleys 22 and 23 of the belt 21 is in a state of being pushed up by the snap pulley 24 in the vicinity of the drive pulley 22. It is supported by a return roller 25 provided on the lower side. Of the belts 21, the upper conveyor belt portions 21a of the pulleys 22 and 23 are supported by the lower carrier roller 26. A motor 27 is connected to the drive pulley 22, and the drive pulley 22 is rotationally driven by the motor 27, so that the belt 21 rotates in a direction in which the upper transport belt portion 21a moves from the tail pulley 23 to the drive pulley 22.

A scraper 28 is provided on the outer peripheral surface of the drive pulley 22. The folded portion of the belt 21 by the drive pulley 22 slides into contact with the scraper 28, and the earth and sand adhering to the belt 21 is removed by the scraper 28. In the vicinity of the scraper 28, an injector 29 for injecting water onto the scraper 28 and the belt 21 is provided. When water is sprayed on the belt 21, the earth and sand adhering to the belt 21 is washed off or softened by water absorption, so that the efficiency of removing the earth and sand is improved.
FIG. 3 is a plan view of a part of the belt 21. As shown in FIG. 3, an uneven portion 21c formed by engraving characters, symbols, numbers, etc. is formed on the inner surface of the belt 21.

As shown in FIGS. 1 and 2, the belt inspection device 10 includes a planar light emitting device (plane lighting device) 30, an image pickup device 40, a controller unit (determination unit) 50, and an alarm device 60.

2. 2. Alarm device The alarm device 60 is installed in the vicinity of the belt conveyor 20 or in the tunnel 1. The alarm device 60 is a warning light, a warning display, or a warning speaker.

3. 3. Surface light emitting device The surface light emitting device 30 is arranged between the transport belt portion 21a and the return belt portion 21b of the belt 21, and faces the lower surface of the transport belt portion 21a. The planar light emitting device 30 irradiates the lower surface of the transport belt portion 21a with light (for example, visible light), and the light emitting surface 31 of the planar light emitting device 30 is formed in, for example, a rectangular shape. Since the planar light emitting device 30 faces the lower surface of the transport belt portion 21a, the illuminated portion on the lower surface of the transport belt portion 21a is bright in a wide range and the uniformity of the illuminance distribution is improved. It is preferable that the brightness distribution on the light emitting surface 31 of the planar light emitting device 30 is uniform.
A translucent portion 32 is provided in the central portion of the planar light emitting device 30. The translucent portion 32 is an opening formed in the central portion of the planar light emitting device 30. A transparent plate may be fitted in this opening.

Examples of the planar light emitting device 30 include a point light source array type, a light guide plate type, and a planar light emitting element type. Hereinafter, the point light source array type, the light guide plate type, and the planar light emitting element type will be described.
The point light source array type planar light emitting device 30 includes point light sources (for example, LEDs) arranged in a grid pattern along a plane between the transport belt portion 21a and the return belt portion 21b, and these point light sources and the transport belt portion. It has a diffuser plate that is arranged between the 21a and faces the group of these point light sources. The light emitted from the point light source is diffused when passing through the light diffusing plate, and the diffused light passing through the light diffusing plate is irradiated to the lower surface of the transport belt portion 21a. The light diffusing plate makes the luminance distribution on the light emitting surface 31 of the planar light emitting device 30 uniform. By dividing the diffuser plate into each point light source, a small diffuser plate may be provided for each point light source, and these small diffuser plates may be connected to form a single diffuser plate. In this case, the combination of the point light source and the small diffuser plate is the point light emitter.

The light guide plate type planar light emitting device 30 is arranged between the transport belt portion 21a and the return belt portion 21b, and is aligned with the light guide plate facing the lower surface of the transport belt portion 21a and the outer peripheral end surface of the light guide plate. It has a point light source (for example, an LED) arranged in a row. The light emitted from the point light source is incident on the inside of the light guide plate from the outer peripheral end surface of the light guide plate, and the light incident on the inside of the light guide plate is repeatedly reflected by the surface of the light guide plate to be diffused and guided, and the diffused light is diffused and guided. It emits light from the upper surface of the light guide plate and irradiates the lower surface of the transport belt portion 21a. The light guide plate makes the luminance distribution on the light emitting surface 31 of the planar light emitting device 30 uniform.

The planar light emitting device type 30 has a planar light emitting element (for example, an organic EL element or an inorganic EL element) facing the conveyor belt portion 21a. For example, the planar light emitting device 30 of the planar light emitting element type is called an organic EL sheet or an inorganic EL sheet.

4. Imaging device The imaging device 40 is installed so as to face the lower surface of the transport belt portion 21a, and the imaging range of the image pickup device 40 includes the entire width direction of the lower surface of the transport belt portion 21a. Further, the imaging range of the imaging device 40 is included in the irradiation range of the planar light emitting device 30 on the lower surface of the transport belt portion 21a.

Preferably, the image pickup apparatus 40 is installed between the return belt portion 21b and the planar light emitting device 30, and the optical axis of the image pickup apparatus 40 passes through the translucent portion 32 and has a planar shape on the lower surface of the transport belt portion 21a. It intersects the center of the irradiation range of the light emitting device 30. Therefore, the image pickup apparatus 40 images the lower surface of the transport belt portion 21a through the translucent portion 32 without blocking the light emitted from the light emitting surface 31 of the planar light emitting device 30. The image pickup device 40 may be arranged in the translucent portion 32 so as not to project above the light emitting surface 31.

The image pickup device 40 converts an area-type solid-state image sensor, an optical lens that forms an image of the belt 21 on the solid-state image sensor, and a belt 21 image imaged (photoelectrically converted) by the solid-state image sensor into a digital image. It is provided with an image processing unit and an image processing unit.

The image pickup apparatus 40 periodically executes an image pickup process while the belt conveyor 20 is in operation. The cycle of the image pickup process by the image pickup apparatus 40 is set so that the image pickup range of the belt 21 in the image by one image pickup process and the image pickup range of the belt 21 in the image by the next image pickup process partially overlap each other. The imaging range of is set to be continuous without interruption. The point light source (LED) of the planar light emitting device 30 also blinks at high speed, but since the blinking cycle is sufficiently shorter than the cycle of the imaging process of the imaging device 40, the high speed blinking of the planar light emitting device 30 is continuous. It can be regarded as light emission.

The image obtained by the image pickup process of the image pickup apparatus 40 is a monochrome gradation image in which each pixel value represents a monochrome gradation (for example, a black and white gradation image in which each pixel value represents a white gradation (so-called gray scale image). )). The image obtained by the imaging process of the image pickup apparatus 40 may be a multicolor gradation image (so-called color image), but the multicolor gradation image is converted into a monochrome gradation image by the controller unit 50 described later. Will be converted.

5. The controller unit FIG. 4 is a block diagram showing the configuration of the belt inspection device 10.
The controller unit 50 is a computer having a CPU, GPU, ROM, RAM, a hardware interface, and the like. A surface light emitting device 30, an image pickup device 40, an alarm device 60, a motor driver 27a, and a storage unit 51 are connected to the controller unit 50.

The storage unit 51 is a storage device including a semiconductor memory, a hard disk drive, or the like. The storage unit 51 is readable and writable for the controller unit 50. The storage unit 51 may be built in the housing of the controller unit 50 or may be externally attached. The storage unit 51 stores a program 51a that can be executed by the controller unit 50. The program 51a may be stored in the ROM of the controller unit 50.

6. Processing of the controller unit The processing executed by the controller unit 50 based on the program 51a during the operation of the belt conveyor 20, that is, when the motor 27 is driven by the motor driver 27a will be specifically described below.

Every time an image is transferred from the image pickup device 40 to the controller unit 50, the controller unit 50 acquires the image transferred from the image pickup device 40, records the image in the storage unit 51, and further performs a damaged portion presence / absence determination process. Execute. The damaged portion presence / absence determination process is performed by performing various image processes on the image acquired from the image pickup device 40 by the controller unit 50, and the damaged portion in the image (the damaged portion is a crack generated in the belt 21 or the like. The process of determining the presence or absence of (referring to the region where the fracture is an image) is, for example, as follows. When the image transferred from the image pickup apparatus 40 to the controller unit 50 is a multicolor gradation image (color image), the controller unit 50 converts the multicolor gradation image into a monochrome gradation image, which will be described later. Executes the process of determining the presence or absence of damaged parts.

The damaged portion presence / absence determination process includes a binarization process and a subsequent determination process. First, the binarization process will be described, and then the determination process will be described.
In the binarization process, the controller unit 50 converts the image acquired from the image pickup apparatus 40 into a binary image (for example, a black-and-white image). Specifically, the controller unit 50 compares the pixel value with the predetermined threshold value for each pixel of the image acquired from the image pickup device 40, and if the pixel value is equal to or higher than the predetermined threshold value, the pixel value is set to 1 (white) of 1 bit. If the pixel value is less than a predetermined threshold value, it is converted to 1 bit of 0 (black). Therefore, this predetermined threshold value is a value that serves as a boundary for determining whether or not the pixels in the image acquired from the image pickup apparatus 40 constitute the damaged portion.

Here, the images before and after the binarization process will be described with reference to FIGS. 5 and 6. FIG. 5 is a drawing for explaining how cracks and water are reflected before and after the binarization process, and the monochrome gradation image shown in FIG. 5A adheres to the cracks generated in the belt 21 and the belt 21. It is an image obtained by imaging the belt 21 on the image pickup apparatus 40 so that water is included in the image pickup range, and the binary image shown in FIG. 5 (b) is the monochrome gradation image of FIG. 5 (a). It is an image obtained by binarization processing. FIG. 6 is a drawing for explaining how the uneven portion 21c is captured before and after the binarization process, and the monochrome gradation image shown in FIG. 6A includes the uneven portion 21c of the belt 21 in the imaging range. As described above, the image obtained by imaging the belt 21 on the image pickup apparatus 40, and the binary image shown in FIG. 6 (b) is an image obtained by the binarization process of the image of FIG. 6 (a). be.

As shown in FIGS. 5A and 6A, in the monochrome gradation image, the value (gradation) of the pixels constituting the normal portion 91 representing the surface of the belt 21 is high and is equal to or higher than the predetermined threshold value. , The values of those pixels are converted into 1 (white) of 1 bit, and become a white normal portion 92 on the binary image as shown in FIGS. 5 (b) and 6 (b). On the other hand, as shown in FIG. 5A, since the values of the pixels constituting the damaged portion 93 representing the crack of the belt 21 are low and less than the predetermined threshold value, the values of those pixels are 0 (black) of 1 bit. As shown in FIG. 5 (b), it becomes a black damaged portion 94 on the binary image. Further, as shown in FIG. 5A, since the values of the pixels constituting the noise unit 95 representing the water adhering to the belt 21 are low but equal to or higher than the predetermined threshold, the values of those pixels are 1 bit (1). By converting to white), the noise portion becomes the same as the normal portion 92 as shown in FIG. 5 (b), and the noise portion does not exist in the binary image. Similarly, as shown in FIG. 6, the value of the pixel constituting the noise portion 97 representing the uneven portion 21c of the belt 21 is also converted to 1 (white) of 1 bit, so that the noise portion is present in the binary image. do not do.

By the way, when a crack is formed in the belt 21, when the light of the planar light emitting device 30 is applied to the belt 21, a shadow is generated in the crack, and further, a difference in brightness between the crack and the surface of the belt 21 around the crack is generated. Because it is large, the shadow of the crack appears clearly. The deeper the crack, the clearer the shadow of the crack. In particular, when the crack penetrates the belt 21, the light of the planar light emitting device 30 passes through the crack, and there is no reflected light from the crack toward the image pickup device 40. Therefore, the value of the pixel constituting the damaged portion 93 representing the crack becomes less than a predetermined threshold value, and the crack appears as the damaged portion 94 in the binary image. This is also clear from FIG. 5 (b).

On the other hand, when water adheres to the belt 21, it tends to appear darker than the original color of the belt 21 at the portion where the water adheres. However, since the light of the planar light emitting device 30 is diffused light and the light emitting surface 31 of the planar light emitting device 30 spreads in a planar manner, the light is incident on the water adhering to the belt 21 from a wide range. Then, the light is reflected on the surface of the water adhering to the belt 21, and the value of the pixels constituting the noise portion 95 representing the water becomes equal to or more than a predetermined threshold value, and the water does not appear in the binary image. This is also clear from FIG. 5 (b).

Further, since the light of the planar light emitting device 30 is diffused light and the light emitting surface 31 of the planar light emitting device 30 spreads in a planar manner, light is incident on the uneven portion 21c from a wide range, and the uneven portion 21c It is difficult for shadows to appear, or even if they do occur, the shadows are thin. Therefore, the value of the pixel constituting the noise portion 97 representing the uneven portion 21c becomes equal to or higher than a predetermined threshold value, and the uneven portion 21c does not appear in the binary image. This is also clear from FIG. 6 (b).

In particular, since the planar light emitting device 30 emits light in a planar manner, the uniformity of the illuminance distribution in the irradiation range on the lower surface of the belt 21 is high, and even when the uneven portion 21c or water is on the peripheral edge of the irradiation range, the unevenness is uneven. It is possible to prevent the uneven portion 21c or the image of water from appearing brightly in the monochrome gradation image and the uneven portion 21c or water from appearing in the binary image.

FIG. 7 shows images before and after binarization processing when the planar light emitting device 30 is replaced with a single linear light emitting device (comparative example). In this comparative example, the linear light emitting device is installed below the transport belt portion 21a so as to extend in the width direction of the belt 21 on the upstream side or the downstream side of the image pickup device 40, and light is directed toward the lower surface of the transport belt portion 21a. Was irradiated. The monochrome gradation image shown in FIG. 7 (a) is an image obtained by imaging the belt 21 on the image pickup apparatus 40 so that the crack generated in the belt 21 is included in the image pickup range, and is an image obtained in FIG. 7 (b). The binary image shown in FIG. 7 is an image obtained by the binarization process of the monochrome gradation image of FIG. 7A. As shown in FIG. 7, in the monochrome gradation image, the damaged portion 81 representing the crack of the belt 21 and the noise portion 83 representing the water adhering to the belt 21 appear dark, and the monochrome gradation image is converted into a binary image. Even after conversion, the damaged portion 82 and the noise portion 84 appear black. Comparing the linear light emitting device and the planar light emitting device 30 from FIGS. 5 to 7 above, it is clear that the water adhering to the belt 21 is less likely to appear in the binary image in the planar light emitting device 30. ..

The binary image converted by the binarization process as described above is associated with the image before conversion by the controller unit 50 and recorded in the storage unit 51.
Then, after the binarization process as described above, the controller unit 50 executes a determination process for determining the presence or absence of a damaged portion in the binary image. Specifically, the controller unit 50 recognizes a black region (a region consisting of 0 pixels having a value of 1 bit) in the binary image, and calculates the area of the recognized black region (that is, the number of pixels). , The calculated area is compared with a predetermined second threshold. Then, if the area of the black region is equal to or larger than the second threshold value, the presence or absence of the damaged portion is determined by the controller unit 50 as if the black region is the damaged portion. On the other hand, if the area of the black region is less than the second threshold value, the absence of the damaged portion is determined by the controller unit 50 as if the black region is not the damaged portion. Since such processing is performed, it is possible to prevent minute noise or the like on the image from being erroneously determined as a damaged portion (crack).

Then, when the controller unit 50 confirms the existence of the damaged portion in the binary image, the controller unit 50 activates the alarm device 60. Then, if the alarm device 60 is a warning light, the alarm device 60 lights up or blinks, if the alarm device 60 is an alarm speaker, a warning sound is emitted from the alarm device 60, and the alarm device 60 is a warning display device. For example, an alarm is displayed by the alarm device 60. As a result, the worker can be notified of the warning.

Along with the operation of the alarm 60, the controller unit 50 turns off the motor driver 27a and stops the motor 27. As a result, the belt conveyor 20 is stopped.

7. Effect Since the belt 21 is illuminated by the planar light emitting device 30, as described with reference to FIGS. 5 and 6, the uneven portion 21c formed on the belt 21 by the water adhering to the belt 21 is 0 (1 bit). Black) does not appear in the binary image. Therefore, the water and the uneven portion 21c are not erroneously detected as cracks, and the presence or absence of cracks in the belt 21 can be accurately inspected.

8. Modification Example As shown in FIG. 8, the planar light emitting device 30 may be a linear light emitting device aggregate. That is, the planar light emitting device 30 includes a plurality of linear light emitting devices 36 installed between the transport belt portion 21a and the return belt portion 21b so as to extend in the width direction of the belt 21. These linear light emitting devices 36 are arranged in the transport direction of the belt 21 so that they are adjacent to each other, and the entire aggregate of the linear light emitting devices 36 is arranged on the lower surface of the transport belt portion 21a (particularly within the imaging range of the image pickup device 40). Face to face). When these linear light emitting devices 36 irradiate the lower surface of the transport belt portion 21a with light, it can be regarded as planar light emission as a whole. Here, the linear light emitting device 36 includes a plurality of point light sources (for example, LEDs) arranged in the width direction of the belt 21 between the transport belt portion 21a and the return belt portion 21b, and these point light sources and the transport belt portion 21a. It has a strip-shaped diffuser that is arranged between the two and faces the group of these point light sources. Therefore, the directivity of the linear light emitting device 36 is low, and the light emitted from the linear light emitting device 36 is diffused light. A translucent portion 32 is formed in the central portion of the linear light emitter assembly, and the optical axis of the image pickup apparatus 40 arranged under the linear light emitter aggregate passes through the translucent portion 32 and is a transport belt portion. It intersects the center of the irradiation range of the planar light emitting device 30 on the lower surface of 21a.

10 ... belt inspection device, 20 ... belt conveyor, 21 ... belt, 30 ... planar light emitting device, 36 ... linear light emitting device, 40 ... image pickup device, 50 ... controller unit (judgment unit)

Claims (1)

A belt inspection device that inspects belts on conveyor belts.
An image pickup device that captures a predetermined location on the belt, and an image pickup device.
A determination unit that binarizes the image captured by the image pickup device and determines the presence or absence of a black damaged portion in the binary image obtained by the binarization.
A light guide plate type or surface light emitting element type planar light emitting device that faces the image pickup range of the belt by the image pickup device and irradiates diffused light toward the image pickup range.
The belt is bridged between the pulley on the upstream side in the transport direction and the pulley on the downstream side in the transport direction.
The image pickup device and the planar light emitting device move from the upstream pulley to the downstream pulley of the belt on the upper conveyor belt portion, and from the downstream pulley to the upstream pulley. It is provided between the lower return belt and the lower return belt that runs toward it.
A translucent portion is formed in the central portion of the planar light emitting device, and the imaging device is installed farther from the transport belt portion than the planar light emitting device.
The planar light emitting device illuminates the lower surface of the transport belt portion, and the surface light emitting device illuminates the lower surface of the transport belt portion.
A belt inspection device, wherein the image pickup apparatus images the lower surface of the conveyor belt portion through the translucent portion .

Images