Inspection device

Abstract

Provided is an inspection device that contributes to improving workability in the adjustment of the position or orientation of a reflection surface that changes the orientation of an optical path from an illumination unit toward an imaging unit.　The present invention comprises: a conveyance unit that conveys an inspection object in a fixed direction, said inspection object being a package; an X-ray irradiation unit that irradiates the inspection object with X-rays; an X-ray detection unit that detects X-rays transmitted through the inspection object, and outputs X-ray detection data; an illumination unit that irradiates the inspection object with light; an imaging unit that images an optical image at the back of the inspection object which has been irradiated with the light, and outputs optical image data; a reflection member that is provided partway along the optical path from the illumination unit toward the imaging unit, and comprises a reflection surface for changing the orientation of the optical path; a reflection direction adjustment unit that has the reflection member attached thereto, and adjusts the position and / or orientation of the reflection surface; an image generation unit that generates an X-ray transmission image on the basis of the X-ray detection data, and generates an optical image on the basis of the optical image data; and an inspection unit that identifies the position of contents in the inspection object on the basis of the X-ray transmission image and the optical image.

Description

Inspection Equipment

[0001] The present invention relates to an inspection device that performs inspections such as checking for pinched seals from X-ray transmission images and optical images of an inspection object, which is a package.

[0002] By irradiating the package, which is the object to be inspected, with electromagnetic waves such as X-rays that have a high penetrating power, and detecting the transmitted electromagnetic waves, it is possible to obtain the distribution of transmitted light intensity according to the state of the package's interior. By generating a two-dimensional image (electromagnetic wave transmission image) that expresses this intensity distribution using pixel color tones (tones such as brightness, shading, and intensity of color), it is possible to visualize the state of the package's interior, which cannot be seen from the outside.

[0003] However, because X-rays and other inspections involve seeing through packaging to visualize the inside, it is difficult to identify the packaging itself in the image. For this reason, it is difficult to determine, for example, where the contents or their fragments are located inside the package, or whether the position has come into contact with the sealed portion of the package and become jammed.

[0004] Therefore, for example, Patent Document 1 discloses an inspection device that irradiates one side of a package with light that has low transmittance through objects, such as visible light or near-infrared light, and captures an image from the other side to obtain an optical image in which the position and outline shape of the package are expressed in the form of parts of the package being darker than the surrounding area, and by comparing this with an electromagnetic wave transmission image, the position of the contents etc. within the package can be identified, and it can be inspected to see if the identified position hits the seal, i.e., whether there is any jamming.

[0005] FIG. 2 shows an excerpt of the inspection device 100 disclosed in Patent Document 1, which is related to the present invention.

[0006] The inspection device 100 includes at least a conveying unit 110, an X-ray irradiation unit 120, an X-ray detection unit 130, an illumination unit 140, an imaging unit 150, a reflecting member 160, and a data processing unit 170. Of these components, at least the X-ray irradiation unit 120, the X-ray detection unit 130, the illumination unit 140, the imaging unit 150, and the reflecting member 160 are housed in a housing (not shown). The inspection object W is any package, which is placed on the conveying unit 110 that penetrates the housing, carried into the housing through an inlet provided in the housing, and after inspection, is carried out of the housing through an outlet provided in the housing.

[0007] The transport unit 110 is a belt conveyor, which has a width in the X-axis direction in the three-dimensional Cartesian coordinate system of the X-axis, Y-axis, and Z-axis shown in Figure 2, and by moving the belt in the Y-axis direction, the inspection object W placed on the belt is moved in the Y-axis direction.

[0008] The conveying section 110 is separated into an upstream conveying section 110a and a downstream conveying section 110b, which have the same conveying speed, and a gap section 110c is provided between the upstream conveying section 110a and the downstream conveying section 110b, which is a gap large enough to allow conveying to continue without the inspection object W falling.

[0009] The X-ray irradiation unit 120 irradiates the inspection object W being transported by the transport unit 110 with X-rays.

[0010] The X-ray detection unit 130 periodically detects transmitted X-rays, which are X-rays that have passed through the inspection object W, among the X-rays irradiated onto the inspection object W from the X-ray irradiation unit 120, and outputs X-ray detection data. The X-ray detection unit 130 is an X-ray line sensor in which a plurality of X-ray detection elements are linearly arranged in the X-axis direction, and periodically detects transmitted X-rays while moving the inspection object W, and sequentially collects linear X-ray detection data across the entire width of the inspection object W, thereby obtaining X-ray detection data for the entire inspection object W.

[0011] The X-ray irradiation unit 120 and the X-ray detection unit 130 are arranged opposite each other on one side and the other side in the Z-axis direction, with a gap 110c sandwiched between them.

[0012] The illumination unit 140 irradiates light onto the inspection object W being transported by the transport unit 110 .

[0013] The imaging unit 150 periodically captures optical images behind the light-irradiated inspection object W and outputs optical image data. The imaging unit 150 is an optical line sensor in which a plurality of photodetection elements are linearly arranged in the X-axis direction, and periodically captures optical images while moving the inspection object W, and sequentially collects the linear optical image data across the entire width of the inspection object W, thereby obtaining optical image data of the entire inspection object W.

[0014] The illumination unit 140 and the imaging unit 150 are disposed on one side and the other side of the gap 110c in the Z-axis direction, respectively.

[0015] The X-ray irradiation unit 120, the X-ray detection unit 130, the illumination unit 140, and the imaging unit 150 are arranged so that an optical path L1 from the X-ray irradiation unit 120 to the X-ray detection unit 130 and an optical path L2 from the illumination unit 140 to the imaging unit 150 pass parallel to each other in the Z-axis direction in the gap 110c, as shown in Fig. 2. Furthermore, the X-ray irradiation unit 120 and the imaging unit 150 are arranged on one side of the transport unit 110 in the Z-axis direction, and the X-ray detection unit 130 and the illumination unit 140 are arranged on the other side.

[0016] In addition, on the side where the X-ray irradiation unit 120 is provided, a reflecting member 160 having a reflecting surface inclined at 45 degrees with respect to the XZ plane is provided in the optical path L2 to change the direction of the optical path L2 from the Z-axis direction to the Y-axis direction, and the imaging unit 150 is disposed at the end of the changed direction of the optical path L2. That is, the light irradiated from the illumination unit 140 is irradiated toward the inspection object W passing over the gap 110c, and is further reflected in a different direction by the reflecting surface of the reflecting member 160 to reach the imaging unit 150.

[0017] The data processing unit 170 generates an X-ray transmission image of the inspection object W based on the X-ray detection data collected by the X-ray detection unit 130, and generates an optical image of the inspection object W based on the optical image data collected by the imaging unit 150. Then, based on the outline of the inspection object W, which is a package, grasped from the optical image, the data processing unit 170 identifies the position of the contents, etc. within the inspection object W, and inspects whether the identified position corresponds to the seal portion, i.e., whether there is any jamming.

[0018] Patent No. 5884145

[0019] In the case of the inspection device 100 shown in FIG. 2 , the position and orientation of the reflective surface of the reflective member 160 are adjusted before shipment so that the imaging unit 150 can properly capture an optical image. However, due to circumstances after shipment, such as vibrations during transportation, vibrations at the installation site, or loosening of the reflective member 160, misalignment in the position or orientation may occur, resulting in an inability to obtain a normal image. One method for dealing with this misalignment is to use software to compensate for the misalignment through image processing. However, if the misalignment is large, image processing alone cannot adequately compensate, and it is therefore necessary to adjust the position and orientation of the reflective surface. However, because the reflective member is generally fixed with screws or the like, adjustment requires removing the screws or the like to release the fixation, adjusting the position and orientation, and then re-fixing the screws or the like, which requires skill and effort and reduces workability.

[0020] An object of the present invention is to provide an inspection device that contributes to improving the workability of adjusting the position and orientation of a reflecting surface that changes the direction of the optical path from the illumination unit to the imaging unit.

[0021] The inspection device of the present invention comprises a transport unit that transports the inspection object, which is a package, in a certain direction; an X-ray irradiation unit that irradiates X-rays onto the inspection object; an X-ray detection unit that detects X-rays that have passed through the inspection object and output X-ray detection data; an illumination unit that irradiates light onto the inspection object; an imaging unit that captures an optical image behind the inspection object irradiated with light and outputs optical image data; a reflective member that is provided midway along the optical path from the illumination unit to the imaging unit and has a reflective surface that changes the direction of the optical path; a reflection direction adjustment unit to which the reflective member is attached and that adjusts the position and / or orientation of the reflective surface; an image generation unit that generates an X-ray transmission image of the inspection object based on the X-ray detection data and generates an optical image of the inspection object based on the optical image data; and an inspection unit that identifies the position of the contents within the inspection object based on the X-ray transmission image and the optical image.

[0022] The X-ray irradiation unit, the imaging unit, and the reflecting member may be located on one side of the transport unit, and the X-ray detection unit and the illumination unit may be located on the other side.

[0023] The imaging device may further include an image adjustment unit that corrects the optical image and / or the X-ray transmission image by image processing.

[0024] According to the present invention, the position and inclination of the reflecting surface can be easily changed without attaching or detaching the reflecting member, thereby improving the workability of adjustment.

[0025] 1 is a diagram showing an example of the configuration of an inspection device 200 according to the present invention; and FIG. 2 is a diagram showing an example of the configuration of a conventional inspection device 100.

[0026] Hereinafter, each embodiment of the present invention will be described with reference to the drawings. In the following description and drawings, the same functional units are denoted by the same reference numerals, and the description of functional units that have already been described will be omitted or will be described only to the extent necessary.

[0027] 1 is a diagram showing an example of the configuration of an inspection device 200 of the present invention. The inspection device 100 includes a transport unit 110, an X-ray irradiation unit 120, an X-ray detection unit 130, an illumination unit 140, an imaging unit 150, a reflecting member 160, a reflection direction adjustment unit 210, and a data processing unit 270.

[0028] Of these components, at least the X-ray irradiation unit 120, the X-ray detection unit 130, the illumination unit 140, the imaging unit 150, the reflecting member 160, and the reflection direction adjustment unit 210 are housed in a housing (not shown). The inspection object W is placed on a transport unit 110 that passes through the housing, and is carried into the housing through an inlet provided in the housing. After inspection, the inspection object W is carried out of the housing through an outlet provided in the housing. The inspection object W is any package, and examples of the contents include food and various products, and it is expected that foreign matter may be mixed in.

[0029] The conveying unit 110 is a type of conveyor capable of continuously conveying the placed inspection object W in a fixed direction. The conveying unit 110 has a width in the X-axis direction in a three-dimensional Cartesian coordinate system of the X-axis, Y-axis, and Z-axis shown in FIG. 1 , and moves the placed inspection object W in the positive Y-axis direction by moving a placement surface, which is an XY plane, in the positive Y-axis direction. The placement surface of the conveying unit 110 may be a physical surface, such as a belt conveyor, that moves the placed inspection object W along with it, or a virtual surface, such as a drive roller conveyor, that applies power to the placed inspection object W to move it in the positive Y-axis direction. The conveying speed depends on the detection period of the detection element, etc., but is generally from several meters / min to several hundred meters / min in the case of package inspection.

[0030] The conveying section 110 is separated into an upstream conveying section 110a and a downstream conveying section 110b, which have the same conveying speed, and a gap section 110c is provided between the upstream conveying section 110a and the downstream conveying section 110b, which is a gap large enough to allow conveying to continue without the inspection object W falling.

[0031] The X-ray irradiation unit 120 irradiates the inspection object W being transported by the transport unit 110 with X-rays.

[0032] The X-ray detection unit 130 periodically detects transmitted X-rays, which are X-rays that have passed through the inspection object W, among the X-rays irradiated onto the inspection object W from the X-ray irradiation unit 120, and outputs X-ray detection data. The X-ray detection unit 130 is an X-ray line sensor in which a plurality of X-ray detection elements are linearly arranged in the X-axis direction. The X-ray line sensor may be one in a single row, or one in which multiple rows are arranged in the Y-axis direction.

[0033] The X-ray irradiation unit 120 and the X-ray detection unit 130 are disposed opposite each other on one side in the Z-axis direction, sandwiching the gap 110c therebetween. As a result, while the inspection object W is transported in the positive direction of the Y-axis, transmitted X-rays are periodically detected until the entire width passes over the gap 110c, thereby obtaining a plurality of X-ray detection data linearly slicing the inspection object W in the X-axis direction, and by arranging these in chronological order, X-ray detection data for the entire inspection object W can be obtained.

[0034] It should be noted that the radiation and detection do not necessarily have to be X-rays, and any electromagnetic wave that has a relatively high permeability to the packaging of the object to be inspected and a relatively low permeability to the contents or foreign matter can be applied. In this case, it is sufficient to configure an irradiation unit and a detection unit that are compatible with the selected electromagnetic wave.

[0035] The illumination unit 140 irradiates light onto the inspection object W being transported by the transport unit 110. The illumination unit 140 is, for example, a line illumination unit in which a plurality of light-emitting elements are linearly arranged in the X-axis direction. The line illumination unit may be a single line illumination unit, or may be an array of multiple lines in the Y-axis direction. Examples of the light-emitting elements include light-emitting diodes that emit visible light or near-infrared light.

[0036] The imaging unit 150 periodically captures optical images behind the light-irradiated inspection object W and outputs optical image data. The imaging unit 150 is an optical line sensor in which a plurality of photodetection elements are linearly arranged in the X-axis direction. The optical line sensor may be arranged in a single row or in multiple rows in the Y-axis direction.

[0037] The illumination unit 140 and the imaging unit 150 are disposed on one side and the other side of the gap 110c in the Z-axis direction. As a result, while the inspection object W is transported in the positive direction of the Y-axis, images of the light that reaches it are periodically captured until the entire width passes over the gap 110c, thereby obtaining a plurality of optical image data in which the inspection object W is linearly sliced ​​in the X-axis direction, and by arranging these in chronological order, optical image data of the entire inspection object W can be obtained.

[0038] The X-ray irradiation unit 120, the X-ray detection unit 130, the illumination unit 140, and the image capturing unit 150 are arranged so that an optical path L1 from the X-ray irradiation unit 120 to the X-ray detection unit 130 and an optical path L2 from the illumination unit 140 to the image capturing unit 150 pass parallel to each other in the Z-axis direction in the gap 110c, as shown in Fig. 1. This makes it possible to acquire X-ray detection data and optical image data under the same conditions when the inspection object W passes through the gap 110c.

[0039] In order to acquire X-ray detection data and optical image data of the inspection object W passing through the gap 110c under the same conditions, it is desirable to position the optical paths L1 and L2 as close as possible in the gap 110c. However, if the X-ray irradiator 120 and the illumination unit 140 are positioned on one side of the gap 110c in the Z-axis direction and the X-ray detector 130 and the image capture unit 150 are positioned on the other side, X-rays irradiated from the X-ray irradiator 120 may enter the image capture unit 150, or light irradiated from the illumination unit 140 may enter the X-ray detector 130, which may interfere with the inspection. Therefore, as shown in FIG. 1, the X-ray irradiator 120 and the image capture unit 150 may be positioned on one side of the Z-axis direction and the X-ray detector 130 and the illumination unit 140 may be positioned on the other side.

[0040] Furthermore, because the X-ray irradiation unit 120 is generally large in volume, it is not easy to arrange other functional units in close proximity within the limited housing space. Therefore, close placement may be avoided by changing the orientation of the optical path L2 from the illumination unit 140 toward the image capture unit 150 on the side where the X-ray irradiation unit 120 is provided. For example, as shown in FIG. 1 , on the side where the X-ray irradiation unit 120 is provided, a reflecting member 160 having a reflective surface inclined at 45 degrees with respect to the XZ plane may be provided on the optical path L2 to change the orientation of the optical path L2 from the Z-axis direction to the Y-axis direction, and the image capture unit 150 may be located at the end of the changed optical path L2. That is, light emitted from the illumination unit 140 is irradiated toward the inspection object W passing through the gap 110c, and is further reflected in a different direction by the reflective surface of the reflecting member 160 before reaching the image capture unit 150.

[0041] The reflection direction adjustment unit 210 is a mechanism to which the reflective member 160 is attached, and which adjusts the reflection direction of light incident from the illumination unit 140 by changing the position and / or orientation of the reflective surface manually or automatically based on instructions input from an arbitrary input unit not shown to an actuator not shown.

[0042] The reflection direction adjustment unit 210 may employ, for example, a well-known positioning stage according to the desired change in the position or orientation of the reflecting surface. In this case, the reflecting member 160 is attached to the positioning stage, and the reflecting surface is positioned before shipment. After shipment, if a deviation in the position or orientation of the reflecting surface occurs, the positioning stage is operated manually or automatically to perform adjustment. To change the position of the reflecting surface, for example, a linear sliding positioning stage that can slide in the positive and negative directions of each axis of a three-dimensional Cartesian coordinate system may be employed. To change the orientation of the reflecting surface, for example, a tilting positioning stage that can rotate around each axis of a three-dimensional Cartesian coordinate system or a tilting positioning stage that can tilt 360 degrees in each direction may be employed. Different types of positioning stages may also be combined. For example, to change both the position and orientation of the reflecting surface, a tilting positioning stage may be attached to a linear sliding positioning stage, and the reflecting member 160 may be attached to this tilting positioning stage.

[0043] The data processing unit 270 includes an image generating unit 271 and an inspecting unit 272 .

[0044] The image generation unit 271 generates an X-ray transmission image of the inspection object W based on the X-ray detection data collected by the X-ray detection unit 130, and also generates an optical image of the inspection object W based on the optical image data collected by the imaging unit 150.

[0045] The inspection unit 272 inspects the contents of the inspection object W for jamming into the seal, etc., based on the X-ray transmission image and optical image generated by the image generation unit 271. The X-ray transmission image shows the presence of contents and debris in the inspection object W, while the optical image shows the outline of the inspection object W, which is a package. Both images are generated based on data collected under the same conditions. Therefore, by aligning and overlaying the two images, it is possible to identify the position of the contents, etc., within the inspection object W, and to inspect whether the identified position corresponds to the seal, i.e., whether jamming has occurred.

[0046] According to the inspection device 200 configured as described above, the position and orientation of the reflecting surface can be easily changed without attaching or detaching the reflecting member, thereby improving the workability of adjustment.

[0047] The data processing unit 270 may further include an image adjustment unit 273 that corrects, by image processing, the optical image generated by the image generation unit 271, so as to enable more detailed adjustment of image abnormalities caused by deviations in the position or orientation of the reflecting surface. In addition, it is expected that there may be cases where alignment or superposition with the X-ray transmission image cannot be performed well by correcting only the optical image, or where it is easier to align or superposition the two images by correcting the X-ray transmission image than by correcting the optical image. Therefore, the image adjustment unit 273 may have a function of correcting the X-ray transmission image generated by the image generation unit 271 by image processing.

[0048] The image processing performed by the image adjustment unit 273 may include, for example, linear transformation of position or size, or shear transformation. The image processing may be performed automatically based on predetermined rules, or may be performed based on various parameters input by an operator.

[0049] The functions of the data processing unit 270 may be implemented by being written in a program and executed by the CPU of a computer.

[0050] The present invention is not limited to the above-described embodiments. The above-described embodiments are merely examples, and anything that has substantially the same configuration as the technical idea described in the claims of the present invention and exhibits similar effects is included within the technical scope of the present invention. In other words, appropriate modifications are possible within the scope of the technical idea expressed in the present invention, and forms incorporating such modifications and improvements are also included within the technical scope of the present invention.

[0051] DESCRIPTION OF SYMBOLS 100, 200... Inspection device 110... Conveying section 110a... Upstream conveying section 110b... Downstream conveying section 110c... Gap section 120... X-ray irradiation section 130... X-ray detection section 140... Illuminating section 150... Imaging section 160... Reflecting member 170, 270... Data processing section 210... Reflection direction adjusting section 271... Image generating section 272... Inspection section 273... Image adjusting section L1, L2... Light path W... Inspection object

Claims

an X-ray detection unit that detects the X-rays that have passed through the object to be inspected and outputs X-ray detection data; an illumination unit that irradiates light onto the object to be inspected; an imaging unit that takes an optical image behind the object to be inspected that has been irradiated with the light and outputs optical image data; a reflecting member that is provided midway along an optical path from the illumination unit to the imaging unit and has a reflecting surface that changes the direction of the optical path; a reflection direction adjustment unit to which the reflecting member is attached and that adjusts the position and / or direction of the reflecting surface; an image generation unit that generates an X-ray transmission image of the object to be inspected based on the X-ray detection data, and generates an optical image of the object to be inspected based on the optical image data; and an inspection unit that identifies the position of contents within the object to be inspected based on the X-ray transmission image and the optical image.

2. The inspection device according to claim 1, wherein the X-ray irradiation unit, the imaging unit and the reflective member are on one side of the transport unit, and the X-ray detection unit and the illumination unit are on the other side.

3. The inspection device according to claim 1 or 2, further comprising an image adjustment unit that corrects the optical image and / or the X-ray transmission image by image processing.

Images