JP5559527B2 - Inspection device - Google Patents

Description

  The present invention relates to an inspection apparatus that inspects an inspection object based on an image obtained by imaging the inspection object.

  Folding of a sheet flap that inspects whether or not a flap of a sheet as a packaging material conveyed by a caser conveyor is bent so as to be correctly guided by a flap guide provided along the conveying direction of the conveyor A state inspection device is known (see, for example, Patent Document 1). In addition, Patent Documents 2 and 3 exist as prior art documents related to the present invention.

JP 2009-161111 A JP 2009-126564 A JP 2000-065546 A

  Some of the above-described sheets are configured as a packaging container having a shape in which oblique chamfers are formed at four corners by folding a flap with a flap guide. Since the chamfers at the four corners of the packaging container are formed by folding the flap, a gap may be formed in the chamfered portion depending on the folded state of the flap. In addition, as an inspection device for inspecting the chamfered portion gap, image the chamfered portion gap, measure the area of the chamfered portion formed in the chamfered portion based on the brightness distribution in the obtained image, and measure There is an inspection device that determines whether or not there is an abnormality in the packaging container formed according to the size of the area. However, in such an inspection apparatus, since the entire area of the gap formed in the chamfered portion is measured and the presence or absence of abnormality is determined based on the size of the entire area, for example, the shape of the gap is a triangle. In the case of the above, there is a case where the entire area is measured to be small and it is determined that there is no abnormality although it is actually determined that there is an abnormality. And the packaging container which has abnormality in a chamfering part will become high possibility that a packaging will collapse in the middle of conveyance.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an inspection apparatus that can improve the accuracy of determining an abnormality in a portion to be inspected.

The inspection apparatus of the present invention includes an imaging unit that images a predetermined imaging range including an inspection target part of an inspection target, an illuminating unit that illuminates the inspection target part, and the predetermined imaging range acquired by the imaging unit. Obtaining the area of the inspection object part in the inspection region set to include the portion where the inspection object part is shown based on the image, and based on the acquired area of the inspection object part Determining means for determining whether or not there is an abnormality, wherein the determining means divides the inspection area into a plurality of small areas so that the inspection target part is divided into a plurality of small areas, And the inspection target part includes a specific one side extending from one end to the other end, and a flap extending from the one end side of the specific one side is bent toward the other end side and the specific one side And the flat When the gap formed is inspected as the inspection target portion between, it is intended to divide the inspection area based on the specific side in the plurality of small regions.

  According to the present invention, since the presence / absence of abnormality is determined for each of a plurality of small regions in which the inspection target part is divided into a plurality of parts, the abnormality of the inspection target part can be determined finely. For this reason, for example, although the total area is small, it is possible to determine that an inspection target part having a shape including a part to be determined to be abnormal is partly abnormal. Thereby, the precision of the discrimination | determination of abnormality of a test object part can be improved.

  As the discriminating unit, a unit that measures the area of the inspection target portion from an image in a predetermined imaging range may be used. For example, in one aspect of the inspection apparatus of the present invention, the determination unit may acquire the area of the inspection target part in the inspection region based on the brightness of each part in the image of the predetermined imaging range.

  In an aspect in which the discriminating unit measures the area of the inspection target part based on the brightness of each part in the image of the predetermined imaging range, the inspection target part is reflected in the image of the imaging range acquired by the imaging unit. You may further provide the optical system which guides the light of the said illumination means to the said imaging means so that the light of the said illumination means is projected on parts other than a part. In this case, the brightness of the imaging range is enhanced by the light guided by the optical system, so that the area of the inspection target part can be measured more appropriately.

  In an aspect provided with an optical system, any optical system may be used. For example, in one aspect of the inspection apparatus of the present invention, a reflection plate that reflects light from the illumination unit to the imaging unit may be used as the optical system.

  As the determination means, a method that uses the determination result for each of the plurality of small regions in order to determine whether there is an abnormality in the inspection target part may be used. For example, in one aspect of the inspection apparatus of the present invention, the determination unit may determine that there is an abnormality in the inspection target portion when it is determined that there is an abnormality in at least one of the plurality of small regions. . In this case, since it is possible to more reliably determine that there is an abnormality in the inspection target part that includes a part that should be determined as abnormal, it is possible to further improve the accuracy of determining the abnormality of the inspection target part. it can.

As the plurality of small regions, a method for dividing the inspection target portion may be applied. For example, in one embodiment the inspection apparatus of the present invention, the discrimination means, as before Symbol plurality of small regions include a center of the specific side to the boundary, the first end and the other end is another small region to each other the Rukoto dividing the inspection area into two sub-regions to include, the inspection area may be divided into the plurality of small regions on the basis of the said specific side. Further, for example, in one embodiment of the test device of the present invention, the discrimination means, as before Symbol boundary by Rukoto dividing the inspection area into two sub-regions by using a straight line perpendicular to the particular side, the The inspection area may be divided into the plurality of small areas based on a specific side . In this case, the region where the gap as the inspection target part is widened changes depending on the folded state of the flap. For this reason, by using an orthogonal straight line as a boundary so as to bisect a specific side with little contribution to the formation of the gap, the area where the gap changes can be appropriately allocated to two small areas. As a result, for example, an abnormality in a gap having a biased area spread, such as a gap formed in a triangular shape, can be easily and appropriately determined.

  As described above, according to the present invention, it is possible to improve the accuracy of determining abnormality of the inspection target part.

1 is an overall view of an inspection apparatus according to an embodiment of the present invention. The figure which shows an example of the structure of a case. The figure which is an example of the image of the corner of a case, Comprising: The figure in case a square-shaped clearance gap is formed in the corner. The figure which is an example of the image of the corner of a case, Comprising: The figure in case a triangular clearance gap is formed in a corner. The figure which shows typically the discrimination condition output to the monitor, Comprising: The figure which shows the square-shaped clearance gap which has a width of 3 mm. The figure which shows typically the discrimination | determination condition output to the monitor, Comprising: The figure which shows the triangular clearance gap which has a width of 3 mm.

  FIG. 1 is an overall view of an inspection apparatus according to an embodiment of the present invention. The inspection apparatus 1 in FIG. 1 is used for inspection of a case 2 in which a can is packed by a caser (not shown) that packs a beverage can. FIG. 2 is a diagram illustrating an example of the structure of the case 2. As shown in FIG. 2, the case 2 includes a barrel 4 that accommodates a plurality (for example, 24) of cans 3 in a state where the cans 3 are arranged vertically and horizontally, and is folded so that both ends of the barrel 4 are closed. An inner flap 5 and an outer flap 6 to be bonded together are provided. FIG. 2 shows a state where the inner flap 5 is folded and the outer flap 6 is not yet folded. As shown in FIG. 2, the body 4 includes a bottom plate 4 a and a top plate 4 b that cover the bottom side and the top surface of the can 3, and a pair of side plates disposed between the bottom plate 4 a and the top plate 4 b. 4c. The inner flap 5 is connected to both ends of the side plate 4c, and the outer flap 6 is connected to both ends of the bottom plate 4a and the top plate 4b. The four corners C of the bottom plate 4a and the top plate 4b are cut obliquely to form a chamfered portion 4d. Each inner flap 5 is folded in two steps along the chamfered portion 4d with two ruled lines (crease lines) 5a and 5b as bending axes. Therefore, by bonding the inner flap 5 and the outer flap 6 together, the case 2 is configured as a packing container having a shape in which corner surfaces 7 are formed at four corners of a rectangular parallelepiped.

  Returning to FIG. 1, the inspection apparatus 1 is used to inspect the accuracy of the four corners C cut obliquely. As shown in FIG. 1, the inspection device 1 is placed on a conveyance path of a conveyor 9 on which a case 2 is placed and which serves as a conveyance means for conveying the placed case 2. The inspection apparatus 1 includes two cameras 10 as imaging means, two illuminators 11 as illumination means, two reflectors 12 as an optical system, and a discrimination device 13 as a discrimination means. .

  The two cameras 10 are arranged above the conveyor 9 so that each axis Ax is inclined. The axis Ax of each camera 10 is inclined so that the four corners C of the case 2 being conveyed by the conveyor 9 are positioned on the extension of each axis AX. That is, the two cameras 10 can capture images from the upper side, one of the two corners C1 located on one end side 2a of the case 2 and the other of the two corners C2 located on the other end side 2b of the case 2. Are arranged. Each camera 10 is connected to a determination device 13, and an image captured by each camera 10 is input to the determination device 13.

  The two illuminators 11 are respectively disposed below the cameras 10 and above the case 2 so as to irradiate the case 2 and the reflector 12 with light. Further, the two reflecting plates 12 are disposed below the respective illuminators 11 and on one end side 2a and the other end side 2b of the case 2, respectively. Each reflecting plate 12 is formed in a curved shape so that each reflecting surface 12a can reflect the light emitted from the illuminator 11 disposed above the reflecting plate 12 and guide the light to each corner surface 7. Has been.

  The discriminating device 13 is realized by a computer unit including a microprocessor and peripheral devices such as RAM and ROM necessary for its operation, for example. The determination device 13 determines whether there are any abnormalities in the four corners C of the case 2 based on the images output from the cameras 10.

  With reference to FIG. 3 and FIG. 4, the determination method of the presence or absence of abnormality of the four corners C performed by the determination device 13 will be described. The camera 10 images a range including the corner C. Imaging of the range including the corner C by the camera 10 can be realized, for example, by being performed based on a sensor (not shown) provided so that passage of a predetermined position on the conveyor 9 of the case 2 can be detected. Each camera 10 has a predetermined imaging range including a corner C1 on one end side 2a of the case 2 and a predetermined imaging range including a corner C2 on the other end 2b of the case 2 in accordance with passage of a predetermined position of the case 2. Respectively. FIGS. 3 and 4 are diagrams illustrating an example of an image of the corner C of the case 2 captured by the camera 10 and input to the determination device 13. In the case 2, a gap D as an inspection target portion is formed between the chamfered portion 4 d of the corner C and the corner surface 7 depending on a bent state of the inner flap 5 and a bonded state of the inner flap 5 and the outer flap 6. There is a case. In the example shown in FIG. 3, a rectangular gap D indicated by hatching is formed between the chamfered portion 4 d of the corner C and the corner surface 7. As shown in FIG. 3, the inspection region T is set so that the corner C is included in the image captured by the camera 10. The setting of the inspection region T is realized, for example, by setting a certain position in the image in advance. If an image is picked up based on a sensor that detects the passage of a predetermined position in the case 2, the corner C is always placed at a fixed position. Therefore, the inspection region T is set at this fixed position. If so, the corner C is included in the inspection region T. Further, the setting of the inspection region T may be realized by discriminating an edge, a corner C, or a gap D based on brightness and darkness in the image. The inspection region T includes a first small region T1 located on the outer flap 6 side by a straight line S orthogonal to the base Da and the center so as to bisect the base Da of the gap D formed by the top plate 4b, and It is equally divided into two small areas T1, T2 of the second small area located on the side plate 4c side.

  The determination device 13 acquires the area of the gap D included in the inspection region T based on the image captured by the camera 10. The area of the gap D is acquired for each of the first gap D1 included in the first small area T1 and the second gap D2 included in the second small area T2. A well-known technique can be applied to obtain the areas of the gaps D1 and D2. For example, each area is acquired by providing a lightness as a reference, binarizing the inspection area T to lightness exceeding the reference value and lightness below the reference value, and then reversing the lightness and darkness to each gap D1. , D2 is specified, and the area of each gap D1, D2 is measured or calculated. The top plate 4 b is irradiated with light from the illuminator 11, and the light is guided to each corner surface 7 by the reflecting plate 12. For this reason, since the difference in brightness between the gap D and the others is emphasized, the areas of the gaps D1 and D2 can be acquired more appropriately.

  Next, the determination device 13 determines the presence or absence of an abnormality based on the acquired area of the gap D. The determination of whether or not there is an abnormality is performed for each of the small areas T1 and T2. Specifically, an abnormal value that can be determined to be abnormal is set for each of the small regions T1 and T2, and the size is compared between each of the gaps D1 and D2 and each abnormal value. Each abnormal value may be the same value or different values. Then, when the determination result of each of the small regions T1 and T2 indicates that there is no abnormality in any of the small regions T1 and T2, the determination device 13 determines that there is no abnormality in the inspection region T, and the determination of each of the small regions T1 and T2 In any case, if there is an abnormality, it is determined that the inspection region T is abnormal.

  According to this embodiment, the inspection target region T is divided into two small regions T1 and T2, and the presence / absence of abnormality is determined for each of the small regions T1 and T2. Therefore, the abnormality of the gap D can be determined in detail. . In addition, the inspection target region T is composed of two small regions T1 and T2 that include the base Da that is unlikely to contribute to the formation of the region of the gap D, that is, the center of the base Da that can be determined to be a constant value. Since it is equally divided, the area where the shape of the gap D changes can be allocated relatively appropriately to each of the small areas T1 and T2. For this reason, it is possible to appropriately determine a shape other than the square shape, that is, a shape in which the distribution of the area forming the gap D is not uniform and biased and the entire area is small. FIG. 4 shows an image when a triangular gap D is formed at the corner C. In the example of FIG. 4, since the shape of the gap D is formed in a triangular shape, when the area of the entire gap D is calculated, this area becomes a small value. For this reason, when the presence or absence of an abnormality in the gap D is determined only by comparing the size of the entire area of the gap D included in the inspection region T with a predetermined value, the gap should be determined as abnormal. Nevertheless, it may be determined that there is no abnormality. That is, in the form in which the presence or absence of abnormality is determined only by comparing the size of the entire area of the gap D with a predetermined value, when a predetermined value is set for the square gap D, a triangular gap If an abnormality is not properly detected with respect to D and a predetermined value is set for the triangular gap D, the square gap D is detected with no abnormality. there is a possibility. However, according to this embodiment, even when it is determined that there is no abnormality in the first small region T1 including the gap D1 having a relatively small area, there is abnormality in the second small region T2 including the gap D2 having a relatively large area. Since it can be determined, whether or not there is an abnormality can be appropriately determined even if the gap D has a triangular shape. For this reason, compared with the case where the presence / absence of abnormality is determined based on the entire area of the gap D, the gap D to be determined as having an abnormality although the entire area of the gap D is small can be appropriately detected. Thereby, it is possible to improve the accuracy of determining the abnormality of the corner C.

  This invention is not limited to the above-mentioned form, It can implement with a suitable form. In the above-described embodiment, the inspection region T is divided into two equal parts so as to include the center of the base Da, but the present invention is not limited to such a form. For example, the inspection region T may be divided into two in a direction parallel to the bottom surface Da so as to include the center of one side forming the gap as a boundary. Further, the inspection region T is not limited to the form in which the inspection region T is divided into two so as to include the center of one side forming the gap as a boundary, but three or more small regions in which the inspection region divides the inspection object portion. It may be divided into. In this case, the presence / absence of an abnormality in the inspection region can be determined more finely. Further, in the above-described embodiment, it is determined that there is an abnormality in the inspection target area by determining that there is an abnormality in one of the two small areas, but there are a plurality of cases in which the inspection target area classifies the inspection target portion. The form divided into small areas is not limited to such a form. For example, it may be determined that the inspection region is determined to be abnormal when it is determined that there is an abnormality in two or more of the plurality of small regions. Moreover, in the above-mentioned form, although the reflecting plate is used as an optical system, it is not limited to such a form. For example, an illumination unit may be separately provided as the optical system. Moreover, the optical system may be omitted. In addition, the caser to which the above-described inspection apparatus is applied may be provided with a discharge device that discharges the case determined to be abnormal by the inspection apparatus from the conveyance path.

  Using the above-described embodiment, the presence / absence of abnormality in the corner C of the case 2 was determined. The image captured by each camera 10 and the determination status of the determination device 13 are output to a monitor (not shown) to check the determination result.

Example 1
An inspection was performed on Case 2 in which a square gap D having a 3 mm width Ds, which is an allowable limit value, was formed at the corner C. FIG. 5 is a diagram schematically showing the discrimination status output to the monitor for a square gap D having a width Ds of 3 mm. In this embodiment, 800 is set as the upper limit value as the abnormal value for the gap D1 included in the first small region T1, and 700 is set as the upper limit value as the abnormal value for the gap D2 included in the second small region T2. ing. As a result of the measurement, the area of the first gap D1 was measured to be 844, and the area of the second gap D2 was measured to be 761. Since both the measured values of the first small region T1 and the second small region T2 exceed the upper limit value, there is an abnormality in both the first small region T1 and the second small region T2 (in FIG. 5). , “NG” is displayed), and as a result, the inspection target is determined to be defective.

(Example 2)
An inspection was performed on Case 2 in which a triangular gap D having a 3 mm width Ds, which is an allowable limit value, was formed at the corner C. FIG. 6 is a diagram schematically showing the discrimination status output to the monitor for the triangular gap D having a width of 3 mm Ds. In this embodiment, 800 is set as the upper limit value as the abnormal value for the gap D1 included in the first small region T1, and 700 is set as the upper limit value as the abnormal value for the gap D2 included in the second small region T2. ing. As a result of the measurement, the area of the first gap D1 was measured as 172, and the area of the second gap D2 was measured as 770, respectively. In the first small region T1, the measured area of the first gap D1 is within the upper limit value, so it is determined that there is no abnormality (indicated as “OK” in FIG. 6), and the measurement is performed in the second small region T2. Since the area of the second gap D2 exceeds the upper limit, it is determined that there is an abnormality (indicated as “NG” in FIG. 6). And based on the discrimination | determination result of these 1st small area | regions T1 and 2nd small area | region T2, the test object is determined to be defective.

  When the presence or absence of abnormality is determined based on the entire area of the gap D without dividing the inspection region T, the area value of the gap D having the same 3 mm width Ds differs depending on the shape of the gap D. The upper limit to be set was difficult, and the test results were not stable. On the other hand, since the inspection is performed for each of the inspection regions T1 and T2 in two inspection regions T1 and T2, the variation of the area value due to the difference in the shape of the gap D is reduced, and the upper limit value to be determined as defective Easy to set up and stable inspection. As a result, setting and adjustment became easy, and the accuracy of determining the presence or absence of abnormality improved, leading to quality improvement. In addition, by providing the caser to which the inspection apparatus 1 is applied with a discharge device (not shown) for discharging the case 2 that is determined to be abnormal (defective) in the inspection apparatus 1 from the conveyance path, Reduction could be realized.

1 Inspection device 2 Case (inspection object)
10 Camera (imaging means)
11 Illuminator (illumination means)
12 Reflector (optical system)
13 Discriminating device (discriminating means)
T inspection area T1 first small area (plural small areas)
T2 Second small area (multiple small areas)
D Clearance (part to be inspected)
Da base (one specific side)
S straight line Ax axis line

Claims (7)

Imaging means for imaging a predetermined imaging range including an inspection target portion of the inspection target;
Illuminating means for illuminating the inspection object part;
Based on the image of the predetermined imaging range acquired by the imaging means, the area of the inspection target portion in the inspection region set to include the portion where the inspection target portion is reflected is acquired, and the acquired A discriminating means for discriminating the presence or absence of an abnormality of the inspection target part based on the area of the inspection target part;
With
The determination means is configured to determine the presence or absence of abnormality in each of the plurality of small regions by dividing the inspection area into a plurality of small regions such that the inspection target portion are divided into a plurality, said object portion from one end The inspection includes a specific side extending to the other end, and a flap formed between the specific side and the flap is formed by bending a flap extending from the one end of the specific side toward the other end. In the case of being inspected as a target portion, the inspection area is divided into the plurality of small areas based on the specific side.
Inspection apparatus characterized by that.   The inspection apparatus according to claim 1, wherein the determination unit acquires an area of the inspection target portion in the inspection region based on brightness of each portion in the image of the predetermined imaging range.   Optics for guiding the light of the illumination unit to the imaging unit so that the light of the illumination unit is reflected in a portion other than the portion where the inspection target portion is projected in the image of the imaging range acquired by the imaging unit. The inspection apparatus according to claim 2, further comprising a system.   The inspection apparatus according to claim 3, wherein a reflection plate that reflects light of the illumination unit to the imaging unit is used as the optical system.   The inspection apparatus according to any one of claims 1 to 4, wherein the determination unit determines that there is an abnormality in the inspection target part when it is determined that there is an abnormality in at least one of the plurality of small regions. . Said determining means, as a pre-Symbol plurality of small regions include a center of the specific side to the boundary, the two small regions of the examination region such that said other end and said one end is contained in another small region to each other The inspection apparatus according to claim 1 , wherein the inspection area is divided into the plurality of small areas on the basis of the specific one side . Said determining means, as a pre-Symbol boundary, said by dividing the inspection area by using a line perpendicular to the specific side to two small areas, the plurality of small regions of the inspection area relative to the specific side The inspection apparatus according to claim 6 , which is divided into:

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