Article inspection apparatus and article inspection method

Abstract

Provided are an article inspection device and an article inspection method for performing an appearance inspection of a heat-sealed portion of a pillow package in an article in which a content is filled in the pillow package made of a transparent film, the article inspection device and the article inspection method being capable of stably separating the heat-sealed portion of the pillow package from a region other than the heat-sealed portion and accurately performing the appearance inspection of the heat-sealed portion.SOLUTION: The inspection device includes an illumination means 20 which is positioned below an article W and illuminates the article W in a plurality of lighting patterns having different lighting directions, an imaging means 30 which is positioned above the article W and images the article W illuminated by the illumination means 20 to acquire a plurality of pieces of brightness image data for each lighting pattern, and a control means 40 which generates inspection image data Z1 by compositing the plurality of pieces of brightness image data by a photometric stereo method and determines the quality of appearance of a heat-sealed part W1a in the article W based on the inspection image data Z1.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an inspection device for inspecting the appearance of a heat-sealed portion of a pillow package made of a transparent film, and an inspection method for inspecting an article using the inspection device. [Background technology]

[0002] Conventionally, in the manufacturing fields of, for example, medical products, pharmaceuticals, chemicals, and food, there has been known an inspection device for an item that captures an image of the appearance of an item in which a product (contents) is filled in a pillow package, and then performs an appearance inspection of the heat-sealed portion of the pillow package based on the acquired image data. For example, Patent Document 1 discloses an image inspection device (inspection device) that conveys a series of tubular films (pillow packages) in one direction, each filled with a packaged item (contents), and performs a visual inspection (presence or absence of sealing defects, etc.) of the end seal area (heat seal area) of each pillow package.

[0003] The inspection device is equipped with a lighting device (lighting means) consisting of a strip-shaped LED with only one lighting pattern and located below the conveying surface of the pillow packaging, and a camera (imaging means) located above the conveying surface and facing the lighting means. The inspection device is configured so that each time the heat-sealed portion of each pillow package passes between the lighting means and the imaging means, the camera captures an image of the heat-sealed portion illuminated by the lighting means, and the image data thus obtained is then binarized, after which an appearance inspection of the heat-sealed portion of each pillow package is performed based on the image data. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-246307 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when inspecting an item in which contents are filled into a pillow package made of transparent film, the conventional inspection device described above makes it difficult to obtain a clear contrast (difference in light and dark) in the acquired image data between the heat-sealed portion of the pillow package and the area other than the heat-sealed portion (i.e., the area that forms the space portion of the pillow package and the area that shows the background).As a result, it is not possible to reliably separate the two, and it is sometimes difficult to accurately inspect the appearance of the heat-sealed portion.

[0006] The present invention has been made in consideration of the current problems described above, and has an object to provide an inspection device and an inspection method for an article in which contents are filled into a pillow package made of a transparent film, and which performs a visual inspection of the heat-sealed portion of the pillow package, and which can stably separate the heat-sealed portion of the pillow package from the area other than the heat-sealed portion, and which can perform an accurate visual inspection of the heat-sealed portion. [Means for solving the problem]

[0007] The problem to be solved by the present invention is as described above, and the means for solving this problem will now be described.

[0008] In other words, the item inspection device of aspect 1 of the present invention is an item inspection device that performs an appearance inspection of the heat-sealed portion of an item in which contents are filled in a pillow package made of transparent film, and is characterized by comprising: a lighting means located below the item to be inspected and illuminating the item with a plurality of lighting patterns with different lighting directions; an imaging means located above the item and imaging the item illuminated by the lighting means to obtain a plurality of brightness image data for each lighting pattern; and a control means that generates inspection image data by combining the plurality of brightness image data using a photometric stereo method, and judges whether the appearance of the heat-sealed portion of the item is good or bad based on the inspection image data.

[0009] In addition, an item inspection method according to aspect 2 of the present invention is an item inspection method for inspecting the appearance of a heat-sealed portion of a pillow package made of a transparent film, in which contents are filled in the pillow package, and is characterized by comprising: an illumination step of illuminating the item to be inspected from below using a plurality of lighting patterns with different lighting directions; an imaging step of capturing an image of the illuminated item from above to obtain a plurality of brightness image data for each lighting pattern; and a control step of generating inspection image data by synthesizing the plurality of brightness image data using a photometric stereo method, and judging the quality of the appearance of the heat-sealed portion of the item based on the inspection image data.

[0010] In this way, in the item inspection device and item inspection method of the present invention, multiple brightness image data obtained for each lighting pattern of the lighting means are synthesized using a photometric stereo method to generate inspection image data, and the appearance of the heat-sealed portion of the item (more specifically, a pillow package) is judged to be good or bad based on the inspection image data. Therefore, with the item inspection device and item inspection method of the present invention, even if the item to be inspected is one in which contents are filled into a pillow package made of transparent film, the contrast (difference in light and dark) between the heat-sealed portion and the area other than the heat-sealed portion is clear on the inspection image data, and the two can be stably separated, allowing for accurate visual inspection of the heat-sealed portion.

[0011] Furthermore, for example, when an article is illuminated directly from the side being imaged by the imaging means, the illumination light is likely to be diffused by the unevenness formed on the surface of the heat-sealed portion, resulting in halation. However, in the article inspection device and article inspection method of the present invention, an illumination means having multiple lighting patterns is provided as backlight illumination, so that the occurrence of such halation can be suppressed while multiple clear brightness image data can be obtained, and more accurate inspection image data can be generated.Based on this inspection image data, visual inspection of the heat-sealed portion can be performed more accurately and stably. [Effects of the Invention]

[0012] The present invention has the following effects. In other words, the item inspection device and item inspection method of the present invention can stably separate the heat-sealed portion of a pillow package from the area other than the heat-sealed portion, allowing for accurate visual inspection of the heat-sealed portion. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a cross-sectional side view showing the overall configuration of an article inspection device according to an embodiment of the present invention. [Figure 2] 1A and 1B are diagrams for explaining image data acquired by an imaging means, in which (a) is an image diagram showing inspection image data obtained by an object inspection device according to the present invention, and (b) is an image diagram showing inspection image data obtained by conventional technology. DETAILED DESCRIPTION OF THE INVENTION

[0014] Next, one embodiment of the present invention will be described with reference to FIGS.

[0015] [Overall configuration of the item inspection device 1] First, the overall configuration of an article inspection device 1 (hereinafter simply referred to as "inspection device 1") in this embodiment will be described.

[0016] In FIG. 1, an inspection device 1 is provided at the most downstream side of the manufacturing process of an article W, which is formed by filling a pillow package W1 with a content W2, and is a device for inspecting the appearance of the manufactured article W. Specifically, the inspection device 1 is a device that grasps the heat-sealed portion W1a formed on the pillow package W1 and performs a visual inspection of the heat-sealed portion W1a to check for width abnormalities, misalignment, etc.

[0017] In addition, the visual inspection of the item W that can be performed by the inspection device 1 is not limited to the visual inspection of the heat-sealed portion W1a as in this embodiment, but it is also possible to perform other visual inspections of the item W, such as the shape of areas other than the heat-sealed portion W1a in the pillow packaging W1 (i.e., the area that forms the space portion of the pillow packaging W1) and the shape of the entire pillow packaging W1.

[0018] Here, the pillow packaging W1 of the item W, which is the subject of inspection in this embodiment, is made of, for example, a colorless transparent film, but is not limited to this and may be formed, for example, from a transparent film colored in any color. Additionally, any design such as letters or figures may be applied to the surface of the pillow packaging W1.

[0019] Furthermore, in this embodiment, medical instruments such as syringes are filled into the pillow packaging W1 as the contents W2, but this is not limited to this, and the composition of the contents W2 may be anything that can be filled into the pillow packaging W1, such as other medical instruments, medicines (tablets, etc.), cosmetics, food, etc.

[0020] The inspection device 1 mainly comprises a conveying means 10 for conveying the item W to a predetermined inspection section P1, an illumination means 20 positioned below the item W to be inspected, an imaging means 30 positioned above the item W, and a control means 40 for generating inspection image data Z1 (see Figure 2(a)) using image data (hereinafter referred to as "brightness image data" as appropriate) acquired by the imaging means 30, and for determining whether the appearance of the heat-sealed portion W1a of the item W (more specifically, the pillow packaging W1) is good or bad based on the inspection image data Z1.

[0021] In this embodiment, the transport means 10 is, for example, a belt conveyor equipped with a light-transmitting endless transport belt, holds the article W placed thereon, and transports the article W to the inspection section P1. Furthermore, when the article W reaches the inspection section P1, the conveying means 10 temporarily stops the conveying operation until the series of inspection operations in the inspection device 1 is completed.

[0022] Here, the above-mentioned light-transmitting property means a property that allows the illumination light L emitted by the illumination means 20 to be transmitted at a predetermined light transmittance.

[0023] The configuration of the conveying means 10 is not limited to this embodiment, and may be any other mechanism, such as a linear conveying device equipped with a light-transmitting moving table that can move in any horizontal direction, or a configuration in which two belt conveyors are arranged in series and the item W is photographed by the imaging means 30 in the gap between the two belt conveyors. Alternatively, the work table may simply be configured with a translucent placement surface, etc. In this case, the item W is placed on the work table by a worker or a robot, etc., and placed on the placement surface.

[0024] The lighting means 20 is disposed with the LED light source 21 facing upward, and is provided so as to be able to illuminate the article W that has reached the inspection section P1. Here, the LED light source 21 is configured to be able to emit illumination light L using a plurality of lighting patterns with different lighting directions. For example, in this embodiment, it is possible to emit three types of illumination light L, consisting of a first illumination light L1 emitted using a first lighting pattern, a second illumination light L2 emitted using a second lighting pattern, and a third illumination light L3 emitted using a third lighting pattern.

[0025] The lighting means 20 switches the lighting pattern of the LED light source 21 in sequence, and illuminates the article W from below with each illumination light L (first illumination light L1, second illumination light L2, or third illumination light L3).

[0026] The number of lighting patterns of the LED light source 21 is not limited to that in this embodiment, and may be at least three patterns. That is, the number of lighting patterns of the LED light source 21 is set appropriately according to the number of brightness image data required to generate the test image data Z1, as will be described later.

[0027] As the imaging means 30, for example, a so-called digital camera using an imaging element such as a CCD image sensor or a CMOS image sensor can be used. Moreover, the image data (luminance image data) captured by the imaging means 30 may be either color or monochrome.

[0028] The imaging means 30 is disposed with the imaging lens 31 facing downward, and is provided so that at least the entire image of the article W located directly below it falls within the field of view of the imaging means 30.

[0029] As will be described later, the imaging means 30 captures an image of the article W illuminated by the lighting means 20 from above each time the lighting pattern of the LED light source 21 is switched, and acquires a plurality of brightness image data for each lighting pattern. That is, in this embodiment, the lighting means 20 that illuminates the article W with a plurality of lighting patterns is provided as a backlight. Furthermore, the imaging means 30 converts each of the acquired multiple pieces of luminance image data into an electrical signal and transmits it to the control means 40.

[0030] The brightness image data converted into an electrical signal may be transmitted to the control means 40 each time an image is captured by the imaging means 30, or may be transmitted in bulk to the control means 40 after a predetermined number of brightness image data have been accumulated.

[0031] The control means 40 controls the operation of the entire inspection device 1, and as described above, generates inspection image data Z1 using the brightness image data acquired by the imaging means 30, and judges whether the appearance of the heat-sealed portion W1a in the pillow packaging body W1 is good or bad based on the inspection image data Z1.

[0032] The control means 40 includes an arithmetic processing unit consisting of a CPU (Central Processing Unit), a memory unit consisting of a ROM (Read Only Memory), RAM (Random Access Memory), HDD (Hard Disk Drive), etc., and the memory unit pre-stores a program for generating inspection image data Z1 by synthesizing multiple brightness image data acquired by the imaging means 30 for each lighting pattern using a photometric stereo method, and a program for determining whether there are any width abnormalities or positional deviations in the heat-sealed portion W1a of the pillow packaging body W1 based on the inspection image data Z1, and judging whether the appearance of the heat-sealed portion W1a is good or bad.

[0033] Then, after receiving the multiple brightness image data converted into electrical signals from the imaging means 30, the control means 40 immediately executes the above program to generate inspection image data Z1, and based on the inspection image data Z1, judges whether the appearance of the heat-sealed portion W1a of the pillow packaging W1 in the item W is good or bad.

[0034] The control means 40 may be provided with an input means such as a touch panel, and may also be provided with an output means such as a monitor.

[0035] Here, the above-mentioned "photometric stereo method" is a technique in which illumination light L is irradiated onto an object (in this embodiment, an object W) from various directions to obtain multiple luminance image data, the brightness (luminance) of the reflected light on each luminance image data is analyzed, and these multiple luminance image data are synthesized to generate inspection image data Z1 in which the contrast (difference between light and dark) is emphasized according to the three-dimensional shape (convex and concave shape).

[0036] In other words, the brightness (luminance) of the reflected light reflected from the object changes depending on conditions such as the incident angle of the illumination light L to the object and the distance between the object and the light source of the illumination light L. For example, when the incident angle is 90°, the brightness of the reflected light is highest (brightest), while as the distance increases, the brightness of the reflected light decreases (darker). By utilizing such properties of reflected light, the uneven shape of an article is analyzed based on a plurality of brightness image data, and the plurality of brightness image data is combined to generate desired inspection image data.

[0037] The photometric stereo method is a well-known technique for obtaining the three-dimensional shape (convex and concave shape) of an object (item W), and therefore a detailed description thereof will be omitted.

[0038] Here, since the heat-sealed portion W1a of the pillow packaging W1 has unevenness, the above-mentioned photometric stereo method can clearly distinguish between the heat-sealed portion W1a and the portion other than the heat-sealed portion W1a in the pillow packaging W1, and it is therefore thought that visual inspection of the heat-sealed area can be carried out satisfactorily. However, when illumination light L using the photometric stereo method is irradiated onto the pillow packaging W1 and the reflected light is imaged by the imaging means 30 to obtain image data (brightness image data), there is a problem in that halation occurs on the surface of the pillow packaging W1.

[0039] In such cases, the unevenness of the heat-sealed portion W1a cannot be obtained stably, and it is difficult to clearly identify the area where the heat-sealed portion W1a of the pillow packaging body W1 made of transparent film is located on the acquired image data Z2, as shown in Figure 2(b).

[0040] In contrast, as shown in Figure 2(a), in the inspection image data Z1 obtained by irradiating the pillow packaging body W1 with illumination light L using the photometric stereo method as a backlight optical system and capturing the transmitted light using an imaging means 30 to obtain image data (brightness image data), the contrast (difference in brightness) between the heat-sealed portion W1a and the area other than the heat-sealed portion W1a becomes clear, and it can be seen that the two can be stably separated. In other words, on the inspection image data Z1 generated by using the photometric stereo method as a backlight optical system, the area where the heat-sealed portion W1a of the pillow packaging W1 made of transparent film is located can be clearly identified, and based on the inspection image data Z1, an appearance inspection of the heat-sealed portion W1a can be performed with high accuracy.

[0041] [Inspection method for items] Next, an article inspection method performed by the inspection device 1 described above will be described.

[0042] First, as shown in FIG. 1, an article W being conveyed by the conveying means 10 arrives at the inspection section P1, and the conveying operation of the conveying means 10 is temporarily stopped. As a result, the article W is held in a substantially horizontal position by the conveying device 10 in the inspection section P1.

[0043] When the article W is held in the inspection section P1, the illumination means 20, as a backlight optical system, illuminates the article W from below by irradiating the article W with illumination light L from below to above (illumination step S01). At this time, the lighting means 20 switches between a plurality of lighting patterns (first lighting pattern, second lighting pattern, and third lighting pattern) having different lighting directions in a predetermined order, and continuously emits each of the lighting lights L (first lighting light L1, second lighting light L2, and third lighting light L3) for a predetermined period of time.

[0044] When the article W is illuminated by the illumination light L, the imaging means 30 captures an image of the article W from above. At this time, the imaging means 30 captures an image of the article W every time the lighting pattern of the illumination light L is switched. As a result, a plurality of brightness image data for each of the lighting patterns is acquired by the imaging means 30 (imaging step S02).

[0045] The plurality of luminance image data acquired by the imaging means 30 are immediately converted into electrical signals and transmitted to the control means 40 .

[0046] The control means 40 receives multiple luminance image data from the imaging means 30, executes the predetermined program described above, and synthesizes these multiple luminance image data using the photometric stereo method to generate inspection image data Z1 (see Figure 2(a)). Furthermore, the control means 40 judges whether the appearance of the heat-sealed portion W1a of the article W (more specifically, the pillow package W1) is good or bad based on the generated inspection image data Z1 (control step S03).

[0047] When the control means 40 has finished checking whether the appearance of the heat-sealed portion W1a is good or bad, the conveying operation of the conveying means 10 is started again, and the article W is conveyed out of the inspection section P1. This completes the series of steps in the article inspection method.

[0048] As described above, the item inspection device 1 in this embodiment is an item inspection device 1 that performs an appearance inspection of the heat-sealed portion W1a of an item W, which is a pillow package W1 made of a transparent film and filled with contents W2.It is configured to include an illumination means 20 located below the item W to be inspected and that illuminates the item W with multiple lighting patterns with different lighting directions, an imaging means 30 located above the item W and that captures images of the item W illuminated by the illumination means 20 to obtain multiple brightness image data for each lighting pattern, and a control means 40 that generates inspection image data Z1 by combining the multiple brightness image data using a photometric stereo method and judges whether the appearance of the heat-sealed portion W1a of the item W is good or bad based on the inspection image data Z1.

[0049] In addition, the object inspection method in this embodiment is an object inspection method for performing an appearance inspection of the heat-sealed portion W1a of an object W, which is a pillow package W1 made of a transparent film filled with contents W2, and is configured to include an illumination process S01 in which the object W to be inspected is illuminated from below using multiple lighting patterns with different lighting directions, an imaging process S02 in which the illuminated object W is imaged from above to obtain multiple brightness image data for each lighting pattern, and a control process S03 in which the multiple brightness image data are synthesized using a photometric stereo method to generate inspection image data Z1, and the appearance of the heat-sealed portion W1a of the object W is judged to be good or bad based on the inspection image data Z1.

[0050] As described above, in the item inspection device 1 and item inspection method of this embodiment, multiple brightness image data acquired for each lighting pattern of the lighting means 20 are synthesized using a photometric stereo method to generate inspection image data Z1, and the appearance of the heat-sealed portion W1a of the item W (more specifically, the pillow packaging body W1) is judged to be good or bad based on the inspection image data Z1.

[0051] Therefore, according to the item inspection device 1 and item inspection method of this embodiment, even if the object to be inspected is an item consisting of a pillow packaging body W1 made of transparent film filled with contents W2, the contrast (difference in light and dark) between the heat-sealed portion W1a and the area other than the heat-sealed portion W1a is clear on the inspection image data Z1, and the two can be stably separated, allowing for accurate appearance inspection of the heat-sealed portion W1a.

[0052] Furthermore, for example, if the article W is illuminated directly from the side being imaged by the imaging means 30, the illumination light L is diffusely reflected by the unevenness formed on the surface of the heat-sealed portion W1a, which is likely to cause halation. However, in the article inspection device 1 and article inspection method of this embodiment, an illumination means 20 having multiple lighting patterns is provided as backlight illumination, so that the occurrence of such halation can be suppressed while multiple clear brightness image data can be obtained, and more accurate inspection image data Z1 can be generated.Based on this inspection image data Z1, the appearance inspection of the heat-sealed portion W1a can be performed more accurately and stably.

[0053] The above describes one embodiment of the present invention, but the present invention is not limited to such an embodiment, which is merely an example, and it goes without saying that the present invention can be embodied in various other forms without departing from the gist of the present invention. The scope of the present invention is indicated by the claims, and further includes the meaning of equivalents set forth in the claims, and all modifications within the scope of the claims. [Explanation of symbols]

[0054] 1. Inspection equipment (item inspection equipment) 20 Lighting means 30 Imaging means 40 Control Means S01 Lighting process S02 Imaging process S03 Control process W Goods W1 pillow packaging W1a Heat seal section W2 Contents Z1 inspection image data

Claims

1. An inspection device for an article that inspects the appearance of a heat-sealed portion of a pillow package made of a transparent film, the pillow package being filled with contents, comprising: an illumination means positioned below the object to be inspected, for illuminating the object with a plurality of lighting patterns having different illumination directions; an imaging means positioned above the object and configured to capture an image of the object illuminated by the lighting means, thereby acquiring a plurality of brightness image data for each of the lighting patterns; a control means for generating inspection image data by synthesizing the plurality of luminance image data by a photometric stereo method, and for determining whether the appearance of the heat-sealed portion of the article is good or bad based on the inspection image data. An object inspection device characterized by:

2. An inspection method for an article in which a pillow package made of a transparent film is filled with contents, the method comprising: inspecting the appearance of a heat-sealed portion of the pillow package; an illumination step of illuminating an object to be inspected from below the object using a plurality of lighting patterns with different illumination directions; an imaging step of capturing an image of the illuminated object from above the object to acquire a plurality of brightness image data for each of the lighting patterns; a control step of generating inspection image data by synthesizing the plurality of luminance image data by a photometric stereo method, and determining whether the appearance of the heat-sealed portion of the article is good or bad based on the inspection image data.

1. A method for inspecting an article, comprising:

Images