JP2000346813A - Inspection device for surface of article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a high-speed inspection of two or more different thickness surfaces on a conveyer to be performed by picking up an image of reflection light from a surface to be inspected by the use of an optical lens whose image angle is 0 degree. SOLUTION: When an article to be inspected 2 is conveyed to a position of an inspection device 1 by a linear conveyer, an image picked up by an image picking-up mechanism 20 is stored in a memory. Then, the image is image- processed by a processing mechanism 20 so that dirtiness of two surfaces 2a' to 2d' of the article 2 or mixed-in condition of foreign matters can be detected. In this case, a lens whose image angle is 0 degree is used for an optical lens part of an optical part 25, and thereby a side surface 2e' is not detected by a CCD image sensor 22. Accordingly, there is no need of processing such as making in an image processing part and the inspection can be made without dead angle. Consequently, it is possible to perform the inspection with one image picking-up mechanism and to incorporate the inspection process on the way of conveying process, and further to enable high speed processing with an inexpensive system.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an article in the form of a hollow bottle, such as a vial for medicine, or a small article, such as a rubber stopper of the vial, which has a thickness in an imaging direction. The present invention relates to an apparatus for inspecting two or more surfaces having different thicknesses.

[0002]

2. Description of the Related Art Conventionally, for example, medical vials and rubber stoppers for the bottles need to be inspected for their appearance because they are used for medical purposes. Has also been developed.

[0003]

The rubber stopper for the vial has a very complicated shape, has a thickness in the imaging direction, and has a stepped shape. Therefore, it is difficult to simultaneously and uniformly illuminate all the surfaces. Particularly, since the rubber stopper for the vial has a minute concave portion below the groove portion, it is very difficult to illuminate the bottom portion thereof. In order to solve this problem, it is conceivable to dispose an individual lighting device and an imaging camera on each surface. However, this requires automatic inspection with a plurality of imaging cameras, and the determination process of a captured image is complicated. And the price of the equipment rises. In addition, when an article having a shape having a surface and a side face, such as the rubber stopper for the vial bottle, is photographed by an imaging camera through a normal lens, since the angle of view of the lens is not 0 °, an image of the side face of the article is displayed on the surface. The image of the side is taken simultaneously with the image, and the image of the side is usually not sufficiently illuminated and the brightness is lower than that of the surface, so that the image processing in the judgment processing unit becomes complicated and the price of the apparatus rises.

Accordingly, the present invention solves the above-mentioned problems and provides an inexpensive apparatus for inspecting a surface of an article to be inspected having a thickness mainly in an imaging direction having two or more different thicknesses at high speed on a conveyor. Is to do.

[0005]

According to a first aspect of the present invention, there is provided an apparatus for inspecting a surface of an article to be inspected having a thickness in an imaging direction having two or more different thicknesses. An illumination mechanism for irradiating the surface with parallel light, an imaging mechanism for imaging reflected light from the inspection surface, and a processing mechanism for processing a video signal from the imaging mechanism, wherein the imaging mechanism has a field angle of 0. This is an inspection device including an optical lens unit and a two-dimensional camera unit. Claim 2
According to the invention, the illumination mechanism includes a light source unit, a condensing lens unit, and a polarizing plate 1, and the polarizing plate 2 is provided between the two-dimensional camera unit of the imaging mechanism and the article to be inspected.
2. The inspection apparatus according to claim 1, wherein the polarizing plate and the polarizing plate are installed so that their polarization angles are perpendicular to each other.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. In the drawings, the same reference numerals indicate the same or corresponding parts. The embodiments disclosed this time are to be considered in all respects as illustrative and not restrictive.

FIG. 1 shows a side view of the overall configuration of an inspection apparatus (1) according to the present invention. In FIG. 1, the article to be inspected (2) is transported in the direction indicated by the arrow X. FIG. 2 is a diagram showing the entire configuration of the inspection apparatus (1) according to the present invention as viewed obliquely from above. In FIG. 2, the article to be inspected (2) is transported in the direction indicated by the arrow Y.

As can be seen from FIG. 1 and FIG. 2, the inspection apparatus (1) of the present invention has four surfaces (2a), (2) of an object to be inspected (2) having a thickness in the imaging direction.
(b) An apparatus for inspecting (2c) and (2d), comprising an illumination mechanism (10), an imaging mechanism (20), and a processing mechanism (30). The illumination mechanism (10) includes a light source section (11), a condenser lens section (12), and a polarizing plate 1 (13), and an imaging mechanism (20).
Is configured to include an optical lens unit (21), a two-dimensional camera unit (22), an aperture stop unit (23), and a polarizing plate 2 (14).

Next, FIG. 3 shows a sectional view of the illumination mechanism (10) and the image pickup mechanism (20). As shown in FIGS. 1 to 3,
The illuminating light is configured to change its direction from, for example, a horizontal direction to a vertically downward direction by a half mirror (24) and to be incidentally illuminated on the inspection object (2). Further, the reflected light from the inspection object is configured to pass through the half mirror (24) and reach the optical lens unit (21). That is, in the imaging mechanism (20), the light source unit (11)
Are reflected by the half mirror (24), and the surfaces (2a), (2b), and (2c) of the inspected article (2) placed and transported on the transport conveyor (3). )
And (2d) are illuminated from above vertically. The surface (2a), (2b), (2c) of the inspected article
The reflected light from (2d) travels in the opposite direction to the irradiation light, passes through the half mirror (24), and is condensed by the optical lens unit (21) having an image angle of 0 ° of the imaging mechanism (2). And passes through the aperture stop (23) and is detected as an image by the two-dimensional camera (22). FIG. 3 shows the optical path (17) of the reflected light. In this case, there is no lens for converging the reflected light between the optical lens portion (21) and the article to be inspected (2), so that the field distance can be increased and the depth of field is deep. Become. For this reason, the focused range is widened, so that even if the surface of the article to be inspected has a height difference, the entire surface of the article to be inspected is designed to be within the focused range.

The illumination mechanism (10) is an illumination device for uniformly illuminating the upper surface of the article (2) to be inspected, and includes a half mirror (2) placed above the article to be inspected.
4), a halogen lamp (11) as a white light source, a condensing lens (12) for parallel light, a polarizing plate 1 (13), a polarizing plate 2 (14), and a filter (1) for cutting off heat rays of the lamp.
5). FIG. 3 shows an optical path (16) of irradiation light. The polarizing plate 1 (13) and the polarizing plate 2 (14) have a configuration in which the polarization angles are perpendicular to each other. In this case, the illuminating light to be irradiated is parallel light from above vertically to the surface to be inspected, so that the surfaces (2a), (2)
(b) Even if each surface has a height difference such as the (2c) and (2d) surfaces and has a complicated shape, it is possible to obtain a uniform captured image without a brightness difference on all surfaces. Can be. That is, conventionally, a ring illumination is arranged above the inspected article (2), and such a uniform captured image cannot be obtained, and the captured image is as shown in FIG. As can be seen from FIG. 5, when the article to be inspected (2) has a complicated uneven shape, large bright and dark portions are formed in the surface image. The brightest image is the portion (51) obtained by imaging the surface (2a) of the inspected article (2), and the brightest image is the portion (52) obtained by imaging the surface (2b). The next brightest part is the part (53) obtained by imaging the part of the surface (2c), and the surface (2d) of the bottom surface of the minute concave part at the bottom becomes dark image (55) because illumination light does not reach.

The image pickup mechanism (20) includes a CCD image sensor (22) as a two-dimensional camera unit and a lens (26) thereof.
And an optical unit (25).
5) includes an optical lens unit (21), an aperture stop (23),
A half mirror (24) is built in. Further, the CCD image sensor (22) is disposed so that the half mirror (24) enters the field of view by its lens (26), and in the present embodiment, the lens (26) faces vertically downward. I have. The CCD image sensor (22) is composed of, for example, a CCD of 512 × 480 pixels, and corresponds to the states of the surfaces (2a), (2b), (2c) and (2d) of the inspected article (2). It captures a dimensional light-dark pattern.

FIG. 6 shows an example of a video image when the object to be inspected (2) is photographed using an optical lens having an angle of view other than 0 °. As shown in FIG. 6, an image (61) of the surface (2a) of the inspected article (2) and an image (6) of the surface (2b)
2) Not only the image (63) of the surface (2c) and the image (64) of the surface (2d), but also the side surface (2e) forming the groove.
A part of the necessary image (63) is missing due to the shadow (65) of the image, and the necessary image (6) is
Part of 4) will be missing. As described above, the surface of the article to be inspected (2) cannot be photographed as an image unless a normal lens is used at infinity telephoto. In the case of the present invention, the optical lens unit (21) uses a lens having an angle of view (a range in which an image is captured is represented by an angle) of 0 degree.
The principal ray (17) of the reflected light from the inspected article (2) is parallel to the optical axis. As described above, according to the present invention, since the angle of view is 0 degree, the side surface (2e) is not detected by the CCD image sensor (22). Since the inspection can be performed without any trouble, the configuration of the inspection apparatus is simplified.

The half mirror (24) is inclined by 45 ° with respect to the optical path (16) of the illuminating light, reflects 50% of the illuminating light from the illuminating mechanism (10) and reflects the object to be inspected on the conveyor (3). Irradiate (2). Half mirror (24)
Is a surface (2a) which is an inspection surface of the article to be inspected (2);
50% of the reflected light reflected in (2b), (2c) and (2d) is transmitted to reach the optical lens (21).

The aperture stop (23) is configured so that its circular opening can be changed substantially continuously by operating its movable part. By changing the diameter of this circular opening, the inspected article (2)
The aperture diameter can be narrowed according to the height difference from the surfaces (2a), (2b), (2c), and (2d), which are the inspection surfaces. By doing so, an image suitable for inspection is formed on the CCD image sensor (22) via the optical lens (21). The lighting mechanism (1
As the halogen lamp (11) of (0), a large light amount lamp is used to reduce the aperture at the opening.

Next, the processing mechanism (30) will be described. A processing mechanism (30) for processing and determining the captured image data; an image processing unit for extracting characteristic data of the image; a memory for storing characteristic data of non-defective products; It is composed of a judgment unit for judging good or bad.

Next, using the inspection apparatus (1) of the present invention, the surface (2a) of the object to be inspected (2) having four different thicknesses,
The operation at the time of inspecting (2b), (2c) and (2d) will be described.

First, the article to be inspected (2) is placed on a linear conveyor (3), which is a transport mechanism, with its vertical direction as shown in FIG. 2, and is moved to the position of the inspection apparatus (1). The sheet is conveyed in the indicated Y direction.

Next, the detection of the article (2) on the conveyor (3), for example, a photoelectric sensor (not shown), detects that the article (2) has entered the area of the inspection apparatus (1). , Is input to the processing mechanism (30). The processing mechanism (30) receives a signal from the photoelectric sensor and accumulates an image captured by the imaging mechanism (20) in an image memory. The conveyor (3) may be operated intermittently or continuously.
It is preferable to operate continuously to improve the processing capacity.

FIG. 4 shows an example of an image stored through the CCD image sensor (22). In FIG. 4, it can be seen that the surface (2a), (2b), (2c) and (2d) of the inspected article (2) are photographed, but the side surface (2e) is not photographed. In this case, the inspected article (2)
The reflected light from the lens passes through the half mirror (24) and enters the optical lens (21), and the emitted light forms an image on the CCD image sensor.

The image picked up by the image pick-up mechanism (20) is subjected to image processing of a two-dimensional image by the processing mechanism (30), whereby the surfaces (2a), (2)
Defects such as b), (2c) and (2d) can be detected, such as contamination and foreign matter.

Inspection of the surface (2a), (2b), (2c) and (2d) of the article (2) to be inspected by the processing mechanism (30) is completed. It is discharged to the defective product discharge process. This step comprises, for example, an air nozzle and a chute. When the defective product comes to the chute position, the compressed air is discharged from the air nozzle to guide the defective product to the chute. On the other hand, the air nozzle does not operate for the inspected article (2) for which the inspection result is normal, and proceeds to the next step on the conveyor.

[0022]

In the inspection apparatus according to the first aspect of the present invention, when a parallel light is radiated from above the illumination device to the inspection object from above vertically, the inspection device has a complicated shape having two or more surfaces having different heights. Even objects can be uniformly illuminated on all surfaces simultaneously. Further, since a lens having an angle of view of 0 degrees is used, the image of the side surface of the article is not photographed at the same time as the surface image. Therefore, even if the article to be inspected has a thickness in the imaging direction, it can be inspected during transportation by one imaging mechanism, and the inspection step can be incorporated in the transportation step, and an inexpensive system can be used. And can be processed at high speed.

In the inspection apparatus according to the second aspect of the present invention, even if the surface of the article to be inspected is glossy, the first polarizing plate and the second polarizing plate have a right angle of polarization, so that direct reflection occurs. Light does not enter the camera, a uniform image can be obtained, and inspection accuracy can be improved.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an inspection apparatus according to the present invention.

FIG. 2 is a perspective view of an inspection device according to the present invention.

FIG. 3 is a cross-sectional view of a lighting mechanism and an imaging mechanism.

FIG. 4 is an example of a captured image.

FIG. 5 is an example of an image captured by a conventional lighting device.

FIG. 6 is an example of an image captured by a conventional imaging lens.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inspection apparatus 2 Inspected article 3 Conveyor 10 Illumination mechanism 20 Imaging mechanism 30 Processing mechanism

Continued on the front page F term (reference) 2F065 AA49 BB05 BB15 CC00 FF42 FF49 GG02 HH03 HH13 JJ03 JJ09 JJ26 LL00 LL04 LL21 LL30 LL33 PP15 QQ23 QQ24 QQ31 RR08 TT03 2G051 AA18 AA90 AB07 BB03 BC01 BC07 BC07 BC07 BC07

Claims (2)

[Claims] 1. An inspection object 2 having a thickness in an imaging direction.
An apparatus for inspecting surfaces having different thicknesses as described above, an illumination mechanism for irradiating parallel light to an inspection surface of an inspected article, an imaging mechanism for imaging reflected light from the inspection surface, and an image from the imaging mechanism. A testing mechanism configured to process a signal, wherein the imaging mechanism includes an optical lens unit having an angle of view of 0 degrees and a two-dimensional camera unit. The illumination mechanism includes a light source unit, a condenser lens unit, and a polarizing plate, and a polarizing plate is provided between a two-dimensional camera unit of the imaging mechanism and an article to be inspected. 2. The inspection device according to claim 1, wherein the polarizing plate and the polarizing plate are installed so that the polarization angles are perpendicular to each other.