JP4589349B2 - Fuel cladding tube barcode reading method and reader - Google Patents

Description

  The present invention relates to a barcode reading method and a reading apparatus for identifying and managing a fuel cladding tube and the like.

  In order to identify and manage fuel rods and fuel cladding tubes (hereinafter simply referred to as “cladding tubes”) when the fuel rods are used in the manufacturing process of a fuel rod or loaded into a nuclear reactor, A bar code is provided in which each bar is provided in a direction perpendicular to the axial direction of the cladding tube (hereinafter referred to as “circumferential direction”). However, the barcode is divided in the circumferential direction and written on the surface of the cladding tube, and a space or an overlapping portion is generated between the barcode and the barcode.

  As a method for reading a barcode, there are two mainstream methods: a method in which a barcode is irradiated with laser light and the reflected light is read, and a method in which a barcode is read into an image processing apparatus by a camera and read by image processing.

  In the method of reading a barcode with a laser beam, the width that the laser can scan at one time is narrow, so if the area to be scanned is the space or overlap between the barcode and the barcode, the barcode Cannot be read. Further, even if the laser light scanning area is to be expanded, it takes time to scan the laser light, increasing the reading time, and a mechanism for scanning the laser light in the circumferential direction of the cladding tube.

  On the other hand, in the reading method based on image processing, it is necessary to obtain an image having a contrast suitable for reading. However, if the camera's readable range is in the space or overlap between the barcodes described above, an image with a contrast suitable for scanning cannot be obtained, and Difficult to read. In addition, since the surface of the cladding tube has a metallic luster and is cylindrical, it is easily affected by external light and an image with a contrast suitable for reading cannot be obtained. Is difficult to read accurately.

In addition, as a method of reading a barcode by marking using the difference in surface roughness, a detector that detects diffused light from the target is installed in a direction deviating from the direction of regular reflection by irradiation light. There is a method of reading based on the difference in the intensity of diffused light due to the difference (Patent Document 1), but in this case, if the reading surface is a cylindrical surface such as a cladding tube, the configuration of the apparatus becomes complicated.
JP-A-9-218910

  It is an object of the present invention to provide a barcode reading method capable of reliably reading a barcode even when there is a space or an overlapping portion between the barcode and the barcode in the readable range of the camera. It is another object of the present invention to provide a barcode reader for carrying out the reading method.

As a result of intensive studies to solve the above problems, the present inventor has arranged the barcode of the cladding tube in the cylindrical hood that shields external light, and the axis of the cladding tube from the light source provided on the cylindrical hood. Even if there is a space or overlap between barcodes in the readable range of the camera by irradiating light parallel to the direction and processing the image data of the illuminated barcode image, The inventors have found that it is possible to reliably read a barcode, and have completed the present invention.
Hereinafter, the invention of each claim will be described.

The invention described in claim 1
A barcode reading method for reading a barcode in which each bar is provided on the surface of the fuel cladding tube in a direction perpendicular to the axial direction of the fuel cladding tube,
A barcode of the fuel cladding tube is provided in a cylindrical hood having an inner light source, an inner surface for regularly reflecting light from the light source, and an opening, and shielding external light from other than the opening. Place and
In the cylindrical hood, irradiate light from the light source parallel to the axial direction of the fuel cladding tube,
The image data of the barcode irradiated with light from the light source is acquired by a camera disposed facing the opening,
A barcode reading method, wherein the obtained image data is subjected to image processing to read the barcode.

  In the invention of this claim, the barcode provided in the circumferential direction of the cladding tube is covered with a cylindrical hood that blocks light from the outside, and the light source provided in the cylindrical hood is parallel to the axial direction of the cladding tube. Since the light is irradiated, an image having a clear contrast can be obtained, and the barcode can be read reliably.

  As the cylindrical hood, a stainless steel pipe whose inner surface is mirror-finished can be used, and its diameter is preferably about 50 to 80 mm. The length is not particularly limited as long as it is a length that can shield external light from other than the opening. Here, shielding external light means shielding external light to the extent that there is no problem in obtaining an image having sufficient contrast. If the length of the cylindrical hood cannot be taken sufficiently, a light shielding plate for shielding external light may be provided on both sides of the cylindrical hood as necessary.

The inner surface of the cylindrical hood is, for example, mirror-finished or has a metallic luster so that the light from the light source is regularly reflected in multiple directions and the light from the light source is uniformly applied over the entire circumference of the cladding tube. is doing.
The opening is a window for reading a barcode, and faces the camera.

The cladding tube is arranged so that the barcode is located in the cylindrical hood.
A light source is attached to the cylindrical hood so as to illuminate the entire circumference of the cladding tube by irradiating light parallel to the axial direction of the cladding tube. As the light source, a bar light source made of a light emitting diode or the like can be used, and has an illuminance necessary to irradiate the entire barcode. Since the cylindrical hood shields external light from other than the opening, the surface of the cladding tube becomes brighter by irradiating light, and the contrast necessary for reading the barcode can be obtained.

  The barcode irradiated with the light from the light source is acquired as image data by a camera arranged opposite to the opening, and the acquired image data is read by the image processing apparatus. Since the light source irradiates light parallel to the axial direction of the cladding tube and illuminates the entire circumference of the cladding tube, the regular reflection light from the cladding tube does not enter the camera, and a clear contrast is obtained. Since the cladding tube is cylindrical and the bar code is provided on the circumferential surface, regular reflection light enters the camera when light is irradiated from the circumferential direction, and a clear contrast cannot be obtained.

  The barcode reading method described above can also read a barcode provided by marking using a difference in surface roughness.

  That is, when reading a barcode provided by marking using the difference in surface roughness, the regular reflected light from the barcode is not incident on the camera, and the difference in diffuse reflected light from the barcode is detected. There is a need to. Diffuse reflection is likely to occur in a portion having a rough surface, so that diffuse reflection light incident on the camera increases. On the other hand, when the surface is clean, the opposite is the case. Diffuse reflection is less likely to occur, so that less diffused reflected light is incident on the camera. For this reason, a difference in surface roughness becomes a difference in contrast, so that a barcode can be detected. If the inner surface of the cylindrical hood is prone to diffuse reflection (rough surface), diffuse reflection light from the cylindrical hood enters the circumferential direction of the cladding tube, resulting in regular reflection entering the camera. Since the amount of light increases and sufficient contrast cannot be obtained, the inner surface of the cylindrical hood is mirror finished.

The invention described in claim 2
A barcode reader for reading a barcode in which each bar is provided on the surface of the fuel cladding tube in a direction perpendicular to the axial direction of the fuel cladding tube,
A cylindrical hood that has an inner surface that regularly reflects light and an opening, and that shields external light from other than the opening,
A light source that is located inside the cylindrical hood and irradiates light parallel to an axial direction of the fuel cladding tube disposed in the cylindrical hood;
A camera that is arranged opposite to the opening and acquires image data of the barcode irradiated with light from the light source;
A barcode reading apparatus comprising: an image processing apparatus that performs image processing on acquired image data.

  The invention of this claim captures the invention of claim 1 which is an invention of a method from the aspect of an apparatus.

The invention according to claim 3 is the bar code reader,
The bar code reader is characterized in that the light source is arranged in the vicinity of the fuel cladding tube arranged in the cylindrical hood on the camera side.

  In the invention of this claim, since the light source is arranged on the camera side of the cladding tube and the distance between the light source and the cladding tube is closer, the barcode is more irradiated and a barcode image with clearer contrast is obtained. It can be obtained and is preferable.

The invention according to claim 4 is the bar code reader,
The bar code reader according to claim 1, wherein the light source is arranged on both sides of a bar code of the fuel cladding tube arranged in the cylindrical hood.

  In the invention of this claim, since the light sources are arranged on both sides of the barcode, the barcode is more illuminated and a barcode image with clearer contrast can be obtained.

  In the present invention, even when there is a space between the barcode and the barcode or an overlapping portion in the readable range of the camera, the barcode can be reliably read.

  Hereinafter, the present invention will be described based on the best mode. In addition, this invention is not limited to the following embodiment. Various modifications can be made to the following embodiments within the same and equivalent scope as the present invention.

(Example)
FIG. 1 is a configuration diagram showing an embodiment of the present invention. In FIG. 1, a cylindrical hood 1 is made of a stainless steel pipe having a diameter of about 50 mm, a length of about twice the length of the barcode 4 and a mirror-finished inner surface, and an opening for reading the barcode 4. 5 is provided. At both ends of the cylindrical hood 1, light shielding plates 1a and 1b for shielding external light are arranged. Further, bar light sources 3a and 3b made of light emitting diodes are attached to both ends (light shielding plates) 1a and 1b of the cylindrical hood 1.

  The cladding tube 2 is passed from the center of the light shielding plates 1a and 1b, and the barcode 4 is set so as to face the camera with the opening 5 interposed therebetween. The light sources 3 a and 3 b irradiate light toward the barcode 4 in parallel with the axial direction of the cladding tube 2. The illuminance is the illuminance necessary to irradiate the entire barcode 4.

The barcode 4 irradiated with light is read as an image by a camera 6 installed at a position where the barcode 4 can be seen through the opening 5, and the obtained image data is subjected to image processing in the image processing device 7.
The result of the image processing is shown in FIG.

  As shown in FIG. 2, in this case, an image having a clear contrast is obtained over the entire barcode. This is because the influence of external light is blocked by attaching a cylindrical hood, and the light reflected from the surface of the cladding tube is almost incident on the camera by irradiating light parallel to the axial direction of the cladding tube. It is thought that there was not.

(Comparative Example 1)
The cylindrical hood 1 is removed from FIG. 1, the cladding tube 2 is irradiated with light from its circumferential direction, the image of the barcode 4 is acquired by the camera 6, and the obtained image data is imaged in the image processing device 7. Processed.
The result of the image processing is shown in FIG. In FIG. 3, the shaded area indicates the position of the bar code in this cladding tube, indicating that an image with clear contrast was not obtained.

  As shown in FIG. 3, in this case, since the image is not clear in contrast over the entire barcode, the barcode cannot be identified at all even if image processing is performed. This is considered to be because specularly reflected light from the surface of the cladding tube was incident on the camera by irradiating light from the circumferential direction in addition to the influence of external light.

(Comparative Example 2)
The cylindrical hood 1 is removed from FIG. 1, the cladding tube 2 is irradiated with light parallel to the axial direction thereof, an image of the barcode 4 is acquired by the camera 6, and the obtained image data is converted into an image processing device 7. In FIG.
The result of the image processing is shown in FIG. In FIG. 4, the solid line portion represents a portion showing a clear contrast, and the hatched portion represents a portion not showing a clear contrast.

  As shown in FIG. 4, in this case, only a part of the barcode is an image with a clear contrast. If there is a break in the barcode and an overlapping part in this part, even if image processing is performed, the barcode It is difficult to identify the code. This is considered to be due to the influence of external light, and the specularly reflected light is incident on the camera except for the portion irradiated with the light.

  As described above, when there is no cylindrical hood, the influence of light from the outside is large and a clear contrast can be obtained only in the illuminated part. In some cases, the influence of light from the outside is eliminated, and a clear contrast is obtained over the entire barcode.

1 is a conceptual diagram of a barcode reading apparatus according to the present invention. In an Example, it is a figure which shows the image processing result of the obtained barcode image. In Comparative Example 1, it is a figure which shows the image processing result of the obtained barcode image. In Comparative Example 2, it is a figure which shows the image processing result of the obtained barcode image.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cylindrical hood 1a, 1b Light-shielding plate 2 Fuel cladding tube 3a, 3b Light source 4 Barcode 5 Opening part 6 Camera 7 Image processing apparatus

Claims (4)

A barcode reading method for reading a barcode in which each bar is provided on the surface of the fuel cladding tube in a direction perpendicular to the axial direction of the fuel cladding tube,
A barcode of the fuel cladding tube is provided in a cylindrical hood having an inner light source, an inner surface for regularly reflecting light from the light source, and an opening, and shielding external light from other than the opening. Place and
In the cylindrical hood, irradiate light from the light source parallel to the axial direction of the fuel cladding tube,
The image data of the barcode irradiated with light from the light source is acquired by a camera disposed facing the opening,
A barcode reading method comprising: processing the acquired image data to read the barcode. A barcode reader for reading a barcode in which each bar is provided on the surface of the fuel cladding tube in a direction perpendicular to the axial direction of the fuel cladding tube,
A cylindrical hood that has an inner surface that regularly reflects light and an opening, and that shields external light from other than the opening,
A light source that is located inside the cylindrical hood and irradiates light parallel to an axial direction of the fuel cladding tube disposed in the cylindrical hood;
A camera that is arranged opposite to the opening and acquires image data of the barcode irradiated with light from the light source;
An apparatus for reading a barcode, comprising: an image processing apparatus that performs image processing on acquired image data.   The barcode reading apparatus according to claim 2, wherein the light source is disposed in the vicinity of the camera side of the fuel cladding tube disposed in the cylindrical hood.   4. The barcode reader according to claim 2, wherein the light source is disposed on both sides of the barcode of the fuel cladding tube disposed in the cylindrical hood.

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