JP2022111631A - Inspection device - Google Patents

Abstract

To provide an inspection device capable of effectively performing defect inspection of a parting line of a molded object which is formed on an external surface by a die for molding.SOLUTION: An inspection device 10 includes an illumination unit 12, a camera 11, and an inspection part 15. The illumination unit 12 irradiates a PET bottle W1 with illumination light L1. The camera 11 is provided at a position which faces the illumination unit 12 having the PET bottle W1 at the center and which deviates from an extension of a line connecting the PET bottle W1 and the illumination unit 12 at a predetermined angle, and images an external surface of the PET bottle W1 irradiated with the illumination light L1. The inspection part 15 detects the presence or absence of defects of a parting line PL on the basis of an inspection image taken by the camera 11.SELECTED DRAWING: Figure 2

Description

The present invention relates to, for example, an inspection apparatus for inspecting defects in a parting line of a mold for molding formed on the outer surface of a molded product such as resin or glass.

2. Description of the Related Art In recent years, for example, inspection apparatuses for inspecting resin molded products such as PET bottles have been used.
For example, in Patent Document 1, in order to inspect uneven thickness of a transparent object such as a PET bottle using an image processing technique, a transmissive illumination device installed on the opposite side of an imaging device and a PET bottle as an object to be inspected are disclosed. A linear light-shielding object positioned between An inspection device for judging normality and abnormality due to uneven thickness is disclosed.

JP-A-2001-235425

However, the above conventional inspection apparatus has the following problems.
That is, although the inspection apparatus disclosed in the above-mentioned publication is capable of inspecting uneven thickness of a transparent body such as a PET bottle, it is difficult to crack a mold for molding formed on the outer surface of a resin molded product such as a PET bottle. No consideration is given to the conditions under which the lines are clearly visible on the images taken for inspection.

SUMMARY OF THE INVENTION An object of the present invention is to provide an inspection apparatus capable of effectively inspecting the parting line of a molded product formed on the outer surface by a mold for molding.

An inspection apparatus according to a first aspect of the present invention is an inspection apparatus for inspecting defects in a parting line of a mold for molding formed on the outer surface of a molded product molded from a material having optical transparency, An apparatus, an imaging device, and an inspection section are provided. The illumination device irradiates the molded product with illumination light. The imaging device is arranged at a position facing the lighting device centered on the molded product and at a position shifted by a predetermined angle from an extension line connecting the molded product and the lighting device, and is arranged at a position shifted by a predetermined angle from the extension line connecting the molded product and the lighting device. Take an image of the outer surface. The inspection unit detects whether or not there is a defect in the parting line based on the inspection image captured by the imaging device.

Here, for example, in an inspection device for inspecting the presence or absence of defects in the mold parting line portion of a mold for molding formed on the outer surface of a molded product having optical transparency, it is arranged so as to sandwich the molded product together with the lighting device. The imaging device is arranged at a position shifted by a predetermined angle from the straight line extending from the lighting device to the molding.

Materials having optical transparency include, for example, resins and glass.
The mold parting line formed on the outer surface of the molded product is a line formed on the outer surface of the molded product along the mating surface of a mold used in, for example, casting, injection molding, blow molding, and the like. Then, this inspection apparatus inspects the thickness and thickness of the mold parting line, molding defects, etc., using an inspection image obtained by photographing the molded product.
Here, for example, when inspecting the presence or absence of defects in the mold parting line portion of a molding die formed on the outer surface of a molded product such as a resin or glass having light transmittance, an image is captured by an imaging device. It is important whether the parting line is clearly displayed on the inspection image.

In the inspection apparatus of the present invention, as described above, the imaging device arranged to sandwich the molded product together with the lighting device is arranged at a position shifted by a predetermined angle from the straight line extending from the lighting device to the molded product. .
As a result, the inspection can be performed in a state in which the parting line is clearly displayed on the inspection image, compared to the configuration in which the imaging device is arranged on the extension straight line connecting the lighting device and the molded product.
As a result, it is possible to effectively inspect the parting line of the molded product formed on the outer surface by the mold for molding.

An inspection apparatus according to a second invention is the inspection apparatus according to the first invention, wherein the imaging device is arranged at a position where the parting line formed on the outer surface of the molded product is shifted from the front of the imaging device. In this state, an inspection image including the parting line is captured.
As a result, using an inspection image that includes the parting line, which is located at a position that is slightly displaced from the front of the imaging device to the left and right, for example, at a position where the light of the lighting device is likely to hit, defects in the part of the parting line can be detected. It is possible to detect the presence or absence of

An inspection apparatus according to a third invention is the inspection apparatus according to the first or second invention, wherein the predetermined angle is set according to the color or wavelength of illumination light emitted from the illumination device.
As a result, according to the color (wavelength) of the illumination light, the imaging device can be positioned at an optimum angle that makes it easy to see the parting line on the inspection image, effectively inspecting the parting line for defects. can be implemented.

An inspection apparatus according to a fourth invention is the inspection apparatus according to the third invention, and when the illumination light is blue light, the predetermined angle is set to 15 to 35 degrees.
As a result, when the illumination light is blue light (for example, a wavelength of 435 to 480 nm), the optimum predetermined angle is set to 15 to 35 degrees. It is possible to effectively inspect the dividing line for defects.

An inspection apparatus according to a fifth aspect is the inspection apparatus according to the third aspect, wherein the predetermined angle is set to 15 to 35 degrees when the illumination light is red light.
As a result, when the illumination light is red light (for example, a wavelength of 610 to 750 nm), the optimum predetermined angle is set to 15 to 35 degrees. It is possible to effectively inspect the dividing line for defects.

An inspection apparatus according to a sixth aspect is the inspection apparatus according to the third aspect, and when the illumination light is white light, the predetermined angle is set to be greater than 0 degrees and equal to or less than 90 degrees.
As a result, when the illumination light is white light, the optimum predetermined angle is set to be greater than 0 and 90 degrees or less. can be effectively implemented.

An inspection apparatus according to a seventh invention is the inspection apparatus according to any one of the first to sixth inventions, wherein the predetermined angle is set at 20 degrees.
By arranging the imaging device at an optimum angle with respect to the lighting device and the molded product, it is possible to effectively inspect the parting lines using an inspection image in which the parting lines are most visible. can be done.

An inspection apparatus according to an eighth invention is the inspection apparatus according to any one of the first to seventh inventions, further comprising a diffusion plate for diffusing the illumination light emitted from the illumination device.
As a result, for example, by diffusing the illumination light on the molded product using a diffusion plate attached near the exit surface of the lighting device, the inspection can be performed while the molded product contains a light-transmitting liquid. Even when it is implemented, defect inspection of the parting line can be effectively implemented.

An inspection apparatus according to a ninth invention is the inspection apparatus according to any one of the first to eighth inventions, wherein an image processing unit that performs image processing on an inspection image captured by an imaging device includes: I have more. The inspection unit uses the inspection image processed by the image processing unit to detect the presence or absence of defects in the parting line.
As a result, the inspection unit can suitably inspect the parting line using an inspection image that has undergone processing such as making the parting line more visible in the image processing unit, for example.

An inspection apparatus according to a tenth invention is the inspection apparatus according to any one of the first to ninth inventions, further comprising a display section for displaying an inspection image.
As a result, for example, by displaying the inspection result of the inspection unit together with the inspection image on the display unit, the user can refer to the inspection image displayed on the display unit to effectively inspect the defect of the parting line. can be implemented.

An inspection apparatus according to an eleventh invention is the inspection apparatus according to any one of the first to tenth inventions, wherein the lighting device is formed in an elongated bar shape, and the lighting device has a longitudinal Directions are placed along the parting lines.
By using an elongated bar-shaped light source as the lighting device and arranging it so that the longitudinal direction of the light source matches the direction of the parting line, it is possible to obtain an inspection image in which the parting line is easy to see, and to detect defects in the parting line. Inspections can be carried out effectively.

An inspection apparatus according to a twelfth invention is the inspection apparatus according to any one of the first to eleventh inventions, wherein the molded product is molded from resin or glass.
As a result, it is possible to effectively inspect the parting lines formed on the outer surface of the molded product made of resin or glass using an inspection image in which the parting lines are easily visible.

According to the inspection apparatus of the present invention, it is possible to effectively inspect the parting line of a molded product formed on the outer surface by a mold for molding.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram showing the configuration of an inspection device for a parting line of a PET bottle according to an embodiment of the present invention; FIG. 2 is a plan view of the inspection apparatus of FIG. 1; 2(a) is a schematic view showing a normal parting line of a PET bottle to be inspected by the inspection apparatus of FIG. 1; FIG. (b) is a schematic diagram showing an abnormal parting line; FIG. 2 is a schematic diagram showing a beverage-filled PET bottle to be inspected in FIG. 1 ; FIG. 2 is a diagram showing an example of an inspection image (OK) captured by a camera included in the inspection apparatus of FIG. 1; FIG. 2 is a diagram showing an example of an inspection image (NG) captured by a camera included in the inspection apparatus of FIG. 1; The figure which shows the inspection image imaged by the camera arrange|positioned in the position which shifted blue illumination light by a predetermined angle (15 degrees) from the extension line which connects an illuminating device and a PET bottle. The figure which shows the inspection image imaged by the camera arrange|positioned in the position which shifted blue illumination light by a predetermined angle (20 degrees) from the extension line which connects an illuminating device and a PET bottle. The figure which shows the inspection image imaged by the camera arrange|positioned in the position which shifted blue illumination light by a predetermined angle (35 degrees) from the extension line which connects an illuminating device and a PET bottle. FIG. 10 is a diagram showing an inspection image captured without a diffusion plate by a camera arranged at a position where blue illumination light is shifted by a predetermined angle (20 degrees) from an extension line connecting an illumination device and a PET bottle; The figure which shows the inspection image imaged by the camera arrange|positioned in the position which shifted the red illumination light by the predetermined angle (15 degree|times) from the extension line which connects an illuminating device and a PET bottle. The figure which shows the inspection image imaged by the camera arrange|positioned in the position which shifted the red illumination light by a predetermined angle (20 degrees) from the extension line which connects an illuminating device and a PET bottle. The figure which shows the inspection image imaged by the camera arrange|positioned in the position which shifted the red illumination light by a predetermined angle (35 degrees) from the extension line which connects an illuminating device and a PET bottle. FIG. 10 is a view showing an inspection image captured without a diffusion plate by a camera arranged at a position where red illumination light is shifted by a predetermined angle (20 degrees) from an extension line connecting an illumination device and a PET bottle; The figure which shows the inspection image imaged by the camera arrange|positioned in the position which shifted white illumination light by a predetermined angle (0 degrees) from the extension line which connects an illuminating device and a PET bottle. The figure which shows the inspection image imaged by the camera arrange|positioned in the position which shifted white illumination light by a predetermined angle (20 degrees) from the extension line which connects an illuminating device and a PET bottle. The figure which shows the inspection image imaged by the camera arrange|positioned in the position which shifted white illumination light by a predetermined angle (90 degrees) from the extension line which connects an illuminating device and a PET bottle. FIG. 10 is a view showing an inspection image captured without a diffusion plate by a camera arranged at a position where white illumination light is shifted by a predetermined angle (20 degrees) from an extension line connecting an illumination device and a PET bottle; As a comparative example, the figure which shows the inspection image imaged with the camera arrange|positioned in the position which shifted blue illumination light by a predetermined angle (10 degrees) from the extension line which connects an illuminating device and a PET bottle. As a comparative example, the figure which shows the inspection image imaged with the camera arrange|positioned in the position which shifted blue illumination light by a predetermined angle (40 degrees) from the extension line which connects an illuminating device and a PET bottle. As a comparative example, the figure which shows the inspection image imaged by the camera arrange|positioned in the position which shifted the red illumination light by the predetermined angle (10 degrees) from the extension line which connects an illuminating device and a PET bottle. As a comparative example, the figure which shows the inspection image imaged by the camera arrange|positioned in the position which shifted the red illumination light by a predetermined angle (40 degrees) from the extension line which connects an illuminating device and a PET bottle. As a comparative example, the figure which shows the inspection image imaged by the camera arrange|positioned in the position which shifted white illumination light by a predetermined angle (95 degrees) from the extension line which connects an illuminating device and a PET bottle.

An inspection apparatus 10 according to an embodiment of the present invention will be described below with reference to FIGS. 1 to 18. FIG.
As shown in FIG. 1, the inspection device 10 inspects the parting line PL formed on the outer surface of the PET bottle (molded product) W1 for defects.
The PET bottle W1 is a container-shaped molded product made of polyethylene terephthalate (PET), and is molded by, for example, blow molding.

The parting line PL is, for example, a line formed on the outer surface of the molded product along the mating surfaces of a molding die used in blow molding or the like. In this embodiment, the PET bottle W1 as the molded product has two mold parting lines PL formed at positions facing each other along the longitudinal direction.
The inspection apparatus 10 of the present embodiment uses an inspection image of the PET bottle W1 to inspect the thickness and thickness of the parting line, molding defects, and the like.

The inspection apparatus 10 includes a camera (imaging device) 11, an illumination device 12, a diffusion plate 13, an image processing section 14, an inspection section 15, and a display section 16, as shown in FIG.
A camera (imaging device) 11 captures an inspection image including the parting line PL formed on the outer surface of the PET bottle W1 irradiated with the illumination light L1 from the lighting device 12 . Further, as shown in FIG. 2, the camera 11 is arranged at a position shifted by a predetermined angle θ from the extension line connecting the lighting device 12 and the PET bottle W1. In other words, the camera 11 is arranged at a position shifted from the front of the illumination device 12 by a predetermined angle θ.

The illumination device 12 is formed, for example, in the shape of an elongated bar, and its longitudinal direction is arranged along the parting line PL.
As a result, by using an elongated bar-shaped light source as the illumination device 12 and arranging it so that its longitudinal direction is aligned with the direction of the parting line PL, an inspection image in which the parting line PL is easy to see can be obtained. It is possible to effectively inspect the line PL for defects.

When an inspection image is captured by the camera 11, the illumination device 12 irradiates illumination light of a predetermined color (wavelength) to the molded product (PET bottle W1) to be inspected.
The diffusion plate 13 is detachably attached to the illumination light irradiation surface side of the illumination device 12 and diffuses the illumination light emitted from the illumination device 12 . In order to obtain an inspection image suitable for defect inspection of the parting line PL, the diffuser plate 13 is used, for example, when inspecting a PET bottle W1 containing liquid such as a light-transmitting beverage. used.

The image processing unit 14 performs desired image processing on the inspection image captured by the camera 11 and transmits the image-processed inspection image to the inspection unit 15 . The image processing performed by the image processing unit 14 may be processing normally performed in image inspection.
The inspection unit 15 uses the inspection image image-processed by the image processing unit 14 to inspect the parting line PL formed on the outer surface of the PET bottle W1 for defects.

Here, in the defect inspection of the parting line PL formed on the outer surface of the PET bottle W1, either the normal parting line PL shown in FIG. 3(a) or the defective parting line PL shown in FIG. Determine whether or not That is, the parting line PL is formed along the mating surface of the mold during blow molding, and if the width is larger than the desired width, or if cracks, chips, etc. occur, it is determined to be defective. .

More specifically, in the defect inspection of the parting line PL, the inspection unit 15 calculates, for example, the area of the part where the parting line PL is formed, and if the calculated area is larger than a predetermined threshold value, is judged to be defective.
Further, in this embodiment, the inspection of the parting line PL of the empty PET bottle W1 after blow molding may be performed, or the parting line PL of the PET bottle W1 filled with the liquid V1 such as the beverage shown in FIG. Inspection of the line PL may be performed.

When inspecting the parting line PL of the PET bottle W1 containing the liquid V1 such as a beverage shown in FIG. preferable.
As a result, even when the illumination light L1 is diffused by the liquid V1 in the PET bottle W1, the diffusion plate 13 diffuses the illumination light L1 and irradiates it onto the PET bottle W1. can be imaged.

The display unit 16 is, for example, a liquid crystal display panel or the like, and displays an inspection image captured by the camera 11 and image-processed by the image processing unit 14 and an inspection result of the parting line PL by the inspection unit 15 .

<Positional Relationship Between Camera 11 and Lighting Device 12>
Here, the positional relationship between the camera 11 and the illumination device 12 included in the inspection apparatus 10 will be described below.
As described above, as shown in FIG. 2, the camera 11 is shifted by a predetermined angle .theta. placed in position.
The predetermined angle θ is set, for example, according to the color, wavelength, etc. of light emitted from the lighting device 12 so as to be an angle at which an optimum inspection image is captured.

Specifically, when the illumination light L1 is blue light (for example, wavelength 435 to 480 nm), the predetermined angle θ is set to 15 to 35 degrees.
As a result, when the illumination light L1 is blue light, the optimum predetermined angle is set to 15 to 35 degrees, so that the defect inspection of the parting line can be performed using the inspection image in which the parting line PL is easily visible. can be effectively implemented.

When the illumination light L1 is red light (eg, wavelength 610-750 nm), the predetermined angle is set to 15-35 degrees.
As a result, when the illumination light L1 is red light, the optimum predetermined angle is set to 15 to 35 degrees, so that the defect inspection of the parting line can be performed using the inspection image in which the parting line PL is easily visible. can be effectively implemented.

When the illumination light L1 is white light, the predetermined angle is set to be greater than 0 degrees and 90 degrees or less.
As a result, when the illumination light is white light, the optimum predetermined angle is set to be larger than 0 degrees and 90 degrees or less. Inspections can be carried out effectively.

<Inspection of Parting Line PL by Inspection Apparatus 10>
The inspection apparatus 10 of this embodiment includes the illumination device 12, the camera 11, and the inspection section 15, as described above. The illumination device 12 irradiates illumination light L1 toward the PET bottle W1. The camera 11 is arranged at a position facing the lighting device 12 with the PET bottle W1 as the center, and at a position shifted by a predetermined angle from the extension line connecting the PET bottle W1 and the lighting device 12, and is irradiated with the illumination light L1. An image of the outer surface of the PET bottle W1 that has been wrapped is captured. The inspection unit 15 detects whether or not there is a defect in the parting line PL based on the inspection image captured by the camera 11 .

Here, in the inspection image captured by the camera 11, the part where the parting line PL is present appears white. For this reason, the inspection unit 15 determines whether or not there is a defect by, for example, detecting a white line (white pixel) included in the inspection image and calculating the area of the predetermined portion.
For this reason, in the inspection process by the inspection unit 15, "labeling" is selected as a processing item, and a defect determination is performed depending on whether the area of white pixels in the inspection area exceeds a predetermined threshold.

For example, FIG. 5 shows an example of an inspection image (OK) captured by the camera 11 included in the inspection apparatus 10 of FIG.
In the inspection image shown in FIG. 5, although there is a parting line PL in the square inspection area, it is not shown in white. be. Therefore, the inspection unit 15 determines that the inspection image shown in FIG. 5 is "OK" for the defect determination of the parting line PL.

On the other hand, FIG. 6 shows an example of an inspection image (NG) captured by the camera 11 included in the inspection apparatus 10 of FIG.
In the inspection image shown in FIG. 6, there is a mold parting line PL in the square inspection area, and the width of the white portion is relatively large. Therefore, the inspection unit 15 calculates the area (2719) of the white pixels included in the predetermined inspection area in the inspection image, and determines whether or not the value is larger than the threshold, thereby determining whether the parting line PL is defective. is determined as "NG".

<Preferred Predetermined Angle Range>
In the inspection apparatus 10 of the present embodiment, as described above, the camera 11 is positioned facing the lighting device 12 with the PET bottle W1 at the center, and is positioned at a predetermined angle from the extension line connecting the PET bottle W1 and the lighting device 12. placed in a staggered position.
Here, the preferred range of the predetermined angle is set for each color (wavelength) of the illumination light L1 emitted from the illumination device 12. FIG.

Specifically, as described above, when the illumination light L1 is blue light (for example, wavelength 435 to 480 nm), the predetermined angle θ is set to 15 to 35 degrees.
When the illumination light L1 is red light (eg, wavelength 610-750 nm), the predetermined angle is set to 15-35 degrees.
When the illumination light L1 is white light, the predetermined angle is set to be greater than 0 degrees and 90 degrees or less. The white light is formed by mixing the three primary colors of R (red), G (green), and B (blue), for example.

Optimal conditions will be verified with reference to inspection images actually obtained when the colors of the illumination light L1 emitted from the illumination device 12 are set to blue, red, and white and the predetermined angle is changed.
(for blue light)
For example, FIG. 7 shows an inspection imaged with the diffusion plate 13 by the camera 11 arranged at a position shifted by a predetermined angle (15 degrees) from the extension line connecting the illumination device 12 and the PET bottle W1 with the blue illumination light L1. showing the image.

In the inspection image shown in FIG. 7, the parting line PL was visible and could be used as an image for defect inspection of the parting line PL.
FIG. 8 shows an inspection image taken with the diffusion plate 13 by the camera 11 arranged at a position shifted by a predetermined angle (20 degrees) from the extension line connecting the illumination device 12 and the PET bottle W1 with the blue illumination light L1. showing.

As for the inspection image shown in FIG. 8, the parting line PL was also visible, and it could be used as an image for defect inspection of the parting line PL.
FIG. 9 shows an inspection image taken with the diffusion plate 13 by the camera 11 arranged at a position shifted by a predetermined angle (35 degrees) from the extension line connecting the lighting device 12 and the PET bottle W1 with the blue illumination light L1. showing.

In the inspection image shown in FIG. 9, the parting line PL was visible although there was a portion where the illumination light L1 was reflected on the left side of the PET bottle W1, and it could be used as an image for inspecting the defect of the parting line PL.
FIG. 10 shows an inspection imaged without the diffusion plate 13 by the camera 11 arranged at a position where the blue illumination light L1 is shifted by a predetermined angle (20 degrees) from the extension line connecting the illumination device 12 and the PET bottle W1. Show the image.

In the inspection image shown in FIG. 10, the parting line PL was visible and could be used as an image for inspecting the defect of the parting line PL.
From the above, when the illumination light emitted from the illumination device 12 is blue light (for example, a wavelength of 435 to 480 nm), if the predetermined angle θ is in the range of 15 to 35 degrees, the parting line PL is A good, clearly visible inspection image could be obtained.

Also, regarding the presence or absence of the diffusion plate 13, when the blue illumination light L1 and the predetermined angle of 20 degrees were compared, it was possible to confirm the mold parting line PL with substantially the same appearance.
Next, a comparative example for confirming a preferable range of the predetermined angle when the blue illumination light L1 is irradiated in a state shifted by a predetermined angle from the extension line connecting the lighting device 12 and the PET bottle W1 will be described with reference to FIGS. 20 will be described below.

FIG. 19 shows an inspection image captured with the diffusion plate 13 by the camera 11 arranged at a position shifted by a predetermined angle (10 degrees) from the extension line connecting the illumination device 12 and the PET bottle W1 with the blue illumination light L1. showing.
In the inspection image shown in FIG. 19, the parting line PL was hardly visible and could not be used as an image for inspecting the defect of the parting line PL.

FIG. 20 shows an inspection image captured with the diffusion plate 13 by the camera 11 arranged at a position shifted by a predetermined angle (40 degrees) from the extension line connecting the illumination device 12 and the PET bottle W1, with the blue illumination light L1. showing.
In the inspection image shown in FIG. 20, the parting line PL was hardly visible and could not be used as an image for inspecting the parting line PL for defects.

From the results of the inspection images including the above comparative examples, inspection images that can be used for inspection cannot be obtained at the predetermined angles θ of 10 degrees and 40 degrees. A suitable inspection image was obtained in which the parting line PL was clearly visible.
Therefore, when the blue illumination light L1 is irradiated with a predetermined angle from the extension line connecting the lighting device 12 and the PET bottle W1, it was found that the preferable range of the predetermined angle is 15 to 35 degrees.

(for red light)
For example, FIG. 11 shows an inspection imaged with a diffusion plate 13 by a camera 11 arranged at a position shifted by a predetermined angle (15 degrees) from an extension line connecting a lighting device 12 and a PET bottle W1 with red illumination light L1. showing the image.
In the inspection image shown in FIG. 11, the parting line PL was visible and could be used as an image for inspecting the defect of the parting line PL.

FIG. 12 is an inspection image captured with the diffusion plate 13 by the camera 11 arranged at a position shifted by a predetermined angle (20 degrees) from the extension line connecting the illumination device 12 and the PET bottle W1 with the red and blue illumination light L1. is shown.
As for the inspection image shown in FIG. 12, the parting line PL was also visible and could be used as an image for defect inspection of the parting line PL.

FIG. 13 shows an inspection image captured with the diffusion plate 13 by the camera 11 arranged at a position shifted by a predetermined angle (35 degrees) from the extension line connecting the lighting device 12 and the PET bottle W1 with the red illumination light L1. showing.
As for the inspection image shown in FIG. 13, the parting line PL was also visible, and it could be used as an image for defect inspection of the parting line PL.

FIG. 14 shows an inspection imaged without the diffuser plate 13 by the camera 11 arranged at a position shifted by a predetermined angle (20 degrees) from the extension line connecting the illumination device 12 and the PET bottle W1 with the red illumination light L1. Show the image.
In the inspection image shown in FIG. 14, the parting line PL was visible and could be used as an image for inspecting the defect of the parting line PL.

From the above, when the illumination light emitted from the illumination device 12 is red light (for example, wavelength 610 to 750 nm), if the predetermined angle θ is in the range of 15 to 35 degrees, the parting line PL is A good, clearly visible inspection image could be obtained.
As for the presence or absence of the diffusion plate 13, when the results of the red illumination light L1 and the predetermined angle of 20 degrees are compared, the inspection image of FIG. The parting line PL could be confirmed more clearly than the image.

Therefore, when irradiating the red illumination light L1, it is possible to obtain a more preferable inspection image with the diffusion plate 13 when inspecting the parting line PL of the PET bottle W1 containing the liquid V1 such as a beverage. I found that I can do it.
Next, a comparative example for confirming a preferable range of the predetermined angle when the red illumination light L1 is irradiated in a state shifted by a predetermined angle from the extension line connecting the lighting device 12 and the PET bottle W1 will be described with reference to FIGS. 22 will be described below.

FIG. 21 shows an inspection image captured with the diffusion plate 13 by the camera 11 arranged at a position shifted by a predetermined angle (10 degrees) from the extension line connecting the illumination device 12 and the PET bottle W1 with the red illumination light L1. showing.
In the inspection image shown in FIG. 21, the parting line PL was hardly visible and could not be used as an image for inspecting the defect of the parting line PL.

FIG. 22 shows an inspection image captured with the diffusion plate 13 by the camera 11 arranged at a position shifted by a predetermined angle (40 degrees) from the extension line connecting the illumination device 12 and the PET bottle W1, with the red illumination light L1. showing.
In the inspection image shown in FIG. 22, the parting line PL was hardly visible and could not be used as an image for inspecting the parting line PL for defects.

From the results of the inspection images including the above comparative examples, inspection images that can be used for inspection cannot be obtained at the predetermined angles θ of 10 degrees and 40 degrees. A suitable inspection image was obtained in which the parting line PL was clearly visible.
Therefore, when the red illumination light L1 is emitted in a state shifted by a predetermined angle from the extension line connecting the illumination device 12 and the PET bottle W1, the preferable range of the predetermined angle is 15 to 15, as in the case of the blue illumination light L1. It turned out to be 35 degrees.

(for white light)
For example, FIG. 15 shows an inspection imaged with the diffusion plate 13 by the camera 11 arranged at a position shifted by a predetermined angle (0 degree) from the extension line connecting the illumination device 12 and the PET bottle W1 with the white illumination light L1. showing the image.
In the inspection image shown in FIG. 15, the parting line PL was visible and could be used as an image for inspecting the defect of the parting line PL.

FIG. 16 shows an inspection image captured with the diffusion plate 13 by the camera 11 arranged at a position shifted by a predetermined angle (20 degrees) from the extension line connecting the illumination device 12 and the PET bottle W1 with the white illumination light L1. showing.
As for the inspection image shown in FIG. 16, the parting line PL was also visible, and it could be used as an image for defect inspection of the parting line PL.

FIG. 17 shows an inspection image captured with the diffusion plate 13 by the camera 11 arranged at a position shifted by a predetermined angle (90 degrees) from the extension line connecting the illumination device 12 and the PET bottle W1 with the white illumination light L1. showing.
In the inspection image shown in FIG. 17, the parting line PL was visible although there was a portion where the illumination light L1 was reflected on the left side of the PET bottle W1, and it could be used as an image for inspecting the defect of the parting line PL.

FIG. 18 shows an inspection imaged without the diffuser plate 13 by the camera 11 arranged at a position shifted by a predetermined angle (20 degrees) from the extension line connecting the lighting device 12 and the PET bottle W1 with the white illumination light L1. Show the image.
In the inspection image shown in FIG. 18, the parting line PL was visible and could be used as an image for inspecting the defect of the parting line PL.

From the above, when the illumination light emitted from the illumination device 12 is white light, if the predetermined angle θ is in the range of 0 to 90 degrees, which is wider than the above-described blue light and red light, the model It was possible to obtain a suitable inspection image in which the dividing line PL was clearly visible.
As for the presence or absence of the diffuser plate 13, when the result of the white illumination light L1 and the predetermined angle of 20 degrees is compared, the parting line PL is interrupted in the inspection image of FIG. In the inspection image of FIG. 16 with diffusion plate 13, the mold parting line PL could be confirmed more clearly than in the inspection image of FIG.

Therefore, when illuminating the white illumination light L1, it is possible to obtain a more preferable inspection image with the diffusion plate 13 when inspecting the parting line PL of the PET bottle W1 containing the liquid V1 such as a beverage. I found that I can do it.
Next, FIG. 23 shows a comparative example for confirming a preferable range of the predetermined angle when the white illumination light L1 is irradiated in a state shifted by a predetermined angle from the extension line connecting the lighting device 12 and the PET bottle W1. The explanation is as follows.

FIG. 23 shows an inspection image captured with the diffusion plate 13 by the camera 11 arranged at a position shifted by a predetermined angle (95 degrees) from the extension line connecting the lighting device 12 and the PET bottle W1 with the white illumination light L1. showing.
In the inspection image shown in FIG. 23, the parting line PL was hardly visible and could not be used as an image for inspecting the defect of the parting line PL.

From the results of inspection images including the above comparative examples, inspection images that can be used for inspection cannot be obtained at the predetermined angle θ = 95 degrees. A suitable inspection image in which the PL is clearly visible could be obtained.
Therefore, it was found that the preferable range of the predetermined angle is 0 to 90 degrees when the white illumination light L1 is shifted by a predetermined angle from the extension line connecting the lighting device 12 and the PET bottle W1.

[Other embodiments]
Although one embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the gist of the invention.
(A)
In the above-described embodiment, the diffuser plate 13 is provided on the exit surface side of the illumination device 12 in order to perform defect inspection of the parting line PL of the PET bottle W1 containing a beverage (liquid) having light transparency inside. I gave an example and explained it. However, the present invention is not limited to this.
For example, when inspecting a molded product that does not contain a substance that diffuses light, such as a liquid, the diffuser plate may be omitted.

(B)
In the above-described embodiment, an example of performing defect inspection of the parting line PL using an inspection image obtained by imaging the PET bottle W1 irradiated with three colors of illumination light, blue light, red light, and white light, has been described. . However, the present invention is not limited to this.
For example, the illumination light with which the molded product is irradiated is not limited to the above three colors, and may be light with other colors (wavelengths).

(C)
In the above-described embodiment, the PET bottle W<b>1 was described as an example of the molded product to be inspected by the inspection device 10 . However, the present invention is not limited to this.
For example, container-shaped molded articles other than PET bottles may be inspected.
Further, the material of the molded article is not limited to PET, and may be another resin having translucency such as PE, PVC, EVOH (ethylene-vinyl alcohol copolymer), or glass.

(D)
In the above-described embodiment, an example has been described in which the inspection device 10 inspects the parting line PL of the blow-molded PET bottle W1. However, the present invention is not limited to this.
For example, a molded product molded by another molding method using a mold, such as injection molding, may be inspected.

(E)
In the above-described embodiment, an example in which the PET bottle W1 is irradiated with illumination light using the elongated bar-shaped illumination device 12 has been described. However, the present invention is not limited to this.
For example, the illumination device is not limited to a bar-shaped illumination device, and may be a dome-shaped illumination device or other forms of illumination device.

(F)
In the above embodiment, the PET bottle W1 is molded, for example, by a molding die used in blow molding, and the parting line PL is formed on the outer surface of the molded product along the mating surface of the molding die. An example of how it is formed has been described. However, the present invention is not limited to this.

For example, the inspection device may inspect a parting line formed on the outer surface of a molded product molded by other molding methods such as casting and injection molding.

INDUSTRIAL APPLICABILITY The inspection apparatus of the present invention can effectively inspect the parting line of a molded product formed on the outer surface by a molding die. It is widely applicable to an inspection apparatus and method for inspecting molded products.

10 inspection device 11 camera (imaging device)
12 Lighting device 13 Diffusion plate 14 Image processing unit 15 Inspection unit 16 Display unit L1 Illumination light PL Parting line V1 Liquid W1 PET bottle (molded product)
θ angle

Claims (12)

An inspection device for inspecting defects in the parting line of a mold for molding formed on the outer surface of a molded product molded from a material having optical transparency,
a lighting device that irradiates illumination light toward the molded product;
The molding irradiated with the illumination light is arranged at a position facing the lighting device centered on the molded product and at a position shifted by a predetermined angle from an extension line connecting the molded product and the lighting device. an imaging device for imaging the outer surface of an article;
an inspection unit that detects whether or not there is a defect in the parting line based on the inspection image captured by the imaging device;
inspection equipment. The imaging device captures the inspection image including the parting line in a state in which the parting line formed on the outer surface of the molded product is arranged at a position shifted from the front of the imaging device.
The inspection device according to claim 1. The predetermined angle is set according to the color or wavelength of illumination light emitted from the lighting device,
The inspection device according to claim 1 or 2. When the illumination light is blue light, the predetermined angle is set to 15 to 35 degrees,
The inspection device according to claim 3. When the illumination light is red light, the predetermined angle is set to 15 to 35 degrees,
The inspection device according to claim 3. When the illumination light is white light, the predetermined angle is set to be greater than 0 degrees and 90 degrees or less.
The inspection device according to claim 3. The predetermined angle is set to 20 degrees,
The inspection device according to any one of claims 1 to 6. further comprising a diffusion plate for diffusing the illumination light emitted from the lighting device;
The inspection device according to any one of claims 1 to 7. further comprising an image processing unit that performs image processing on the inspection image captured by the imaging device,
The inspection unit uses the inspection image processed by the image processing unit to detect the presence or absence of defects in the parting line.
The inspection device according to any one of claims 1 to 8. further comprising a display unit that displays the inspection image;
The inspection device according to any one of claims 1 to 9. The lighting device is formed in an elongated bar shape,
The lighting device is arranged with its longitudinal direction along the parting line,
The inspection device according to any one of claims 1 to 10. The molded article is molded from resin or glass,
The inspection device according to any one of claims 1 to 11.

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