JP2008215955A - Inverted can detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve an inverted can detection technique easy to adjust erroneous detection or detection timing. <P>SOLUTION: A can product 1 is illuminated from the area above a line before arriving at a package position, where a plurality of can products are rearranged in one row to fill a case, by a CCD camera 2 and the light reflected from the can product 1 is photographed by the camera. By comparing the photographed image with a reference image, it is determined whether the up-and-down direction of the can product 1 is normal. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a technique for detecting a can product that is upside down on a conveyance path for conveying a can product filled with beer or the like to a package position.

For example, Patent Documents 1 and 2 describe a technique in which an inspection site is imaged with a CCD camera and foreign matter or a defect is detected using the captured image.
JP 2005-017003 A JP 2000-055829 A

  For packaging of can products, there are cases where cartons are packed after packing in units of several bottles, or where each book is packed in a carton as it is. The former is called a multi-pack and the latter is called a loose pack. For example, in the case of the former, a beer can product is usually packed in units of 6 and then packed into 24 cartons. In the latter, 24 bottles are packed in a carton.

  In the manufacturing process of can products, when transporting to these packaging positions, the inspector actually picks up multiple can products flowing on the transport path and inspects the can surface for scratches, etc. is there. At this time, if the person inspecting inadvertently turns the can product upside down and returns it to the conveyance path, can products having opposite directions are mixed in the carton.

  The up and down direction of can products is usually fixed, and if for some reason they are found in the market with a mixture of reverse products, the appearance and contents are normal, even if the direction is different. May be perceived as an abnormality in the manufacturing process, causing consumer anxiety and being returned from the market.

  Therefore, in the past, detection was performed using reflection at the recessed portion of the bottom surface (lower surface) 1b of the can product 1 using a pair of fiber sensors 14a and 14b as shown in FIG. Misdetection occurs due to reflection of water droplets adhering upstream of the tab or the conveyance path whose direction is not constant. Further, as shown in FIG. 6, there is a method of detecting that the distance from the can product 1 is close by using a proximity sensor 15 that detects the proximity by light or the like, but the adjustment of the separation distance between the can product 1 and the sensor 15 is possible. Since the tab is only part of the upper surface of the can, it is difficult to set the detection timing that changes depending on the direction of the tab.

  The present invention has been made in view of the above problems, and an object of the present invention is to realize an inverted can detection technique in which erroneous detection is reduced and the attachment position and detection timing of sensors are easily adjusted.

  In order to solve the above-described problems and achieve the object, the upside-down can detection device according to the present invention arranges a plurality of can products 1 having different shapes of the upper surface 1a and the lower surface 1b in a row and packs them in a case in the same posture. The illuminated camera 2 that is provided above the conveyance line 6 before the package position and photographs the can product flowing on the conveyance line from above, and the reflected light from the illumination is photographed by the camera, and the photographed image is a reference image. And a determination circuit 4 that determines whether the vertical direction of the can product is normal.

  Preferably, the can product is provided with a shape portion that does not reflect illumination light only on its upper surface.

  Preferably, the camera is arranged at a predetermined distance from the can product, and the optical axis is inclined at a predetermined angle with respect to the horizontal direction.

  According to the present invention, it is possible to realize an upside-down can detection technique in which erroneous detection is reduced and the attachment positions of sensors and the detection timing can be easily adjusted.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
The embodiment described below is an example as means for realizing the present invention, and the present invention can be applied to a modified or modified embodiment described below without departing from the spirit of the present invention.

  Fig.1 (a) shows schematic structure of the inverted can detection apparatus of this embodiment, (b) has shown the picked-up image of the bottom face of can products. Moreover, Fig.2 (a) shows schematic structure of the inverted can detection apparatus of this embodiment, (b) has shown the picked-up image of the upper surface of a can product. FIG. 3 is a block diagram of the inverted can detection device of the present embodiment. FIG. 4 is a plan view showing a part of a production line in which the inverted can detection device of the present embodiment is arranged.

  As shown in FIG. 1 to FIG. 3, the inverted can detection device of the present embodiment has a CCD camera 2 with a red LED for illumination that images a can product 1 as a subject, and the can product 1 as a subject has reached a shooting position. A trigger sensor 3 that detects this, and a determination circuit 4 that determines whether the can product 1 is in an upright state or a reverse direction by comparing a captured image captured by the CCD camera 2 with a reference image.

  The CCD camera 2 is installed in a posture in which the optical axis of the camera is inclined at a predetermined angle θ with respect to the horizontal direction while being separated from the imaging part of the can product 1 by a predetermined distance.

  The predetermined distance is appropriately adjusted according to the relationship with the focal length that can be adjusted by the camera and the accuracy of the image to be acquired. In the case of a wide field of view (wide shooting angle of view) type camera, a plurality of predetermined distances are used. 38 mm to 42 mm is desirable so that images are not acquired simultaneously, and about 40 mm is more preferable because the clearest image can be obtained. It should be noted that more detailed adjustment is possible with a narrow-field (narrow field of view) type camera.

  The predetermined angle θ can be appropriately adjusted to an angle at which the reflected light can be accurately captured and the difference between the reflected light due to the shape difference between the upper surface and the lower surface can be accurately captured. An experimental result was obtained that the angle of -82 [deg.] Was desirable, and that 79 [deg.] Is the least malfunctioning or erroneous detection.

  The can product 1 is provided with a pull tab-shaped portion on the upper surface 1a where the red LED light for illumination is not reflected, and the bottom surface 1b is formed with a recessed portion having a shape different from that of the upper surface 1a.

  When the bottom surface 1b of the can product 1 is photographed by the CCD camera 2, as shown in FIG. 1B, the illumination light of the LED is reflected in the recessed portion and no other subject is reflected in the photographed image. On the other hand, when the top surface 1a of the can product 1 is photographed by the CCD camera 2, the illumination light of the LED is not reflected by the pull tab as shown in FIG. Pull tab shape is reflected.

  Therefore, in the present embodiment, the image of FIG. 2B is used as a reference image, and a can product is obtained by comparing a photographed image of each can product 1 flowing on the line by the determination circuit 4 with a reference image by a luminance value or the like. It is determined whether 1 is an upright state or a reverse direction state. Even if the threshold value of the luminance value of the reference image is set to a large value in the comparison between the captured image and the reference image, the image in the opposite direction is captured as almost white (the luminance value is larger), so there is reflection due to adhesion of water droplets, etc. However, the “abnormal” state can be easily determined.

  Further, when the determination circuit 4 determines that the can product 1 is in the reverse direction, the alarm 5 generates an alarm and emits an alarm sound or light. At the same time, the conveyor is stopped and the reverse can product is packed in a box. Is prevented. In addition, as shown to Fig.4 (a), the waste disposal apparatus 8 installed downstream may be operated, and only one target can product may be introduced into the separate line 7 for waste.

  The above-described upside down can detection apparatus is behind a position where a person actually picks up a can product 1 filled with contents such as beer and inspects the surface of the can for scratches, and the like. 1 is installed immediately before the package position where a predetermined number of boxes are packed in an upright state. That is, as shown in FIG. 4 (a), the CCD camera 2 is installed above the packaging position 6 where a plurality of can products 1 flowing in the width direction on the line are rearranged in a line and packed into a box, The can products 1 are photographed one by one in synchronization with the detection signal of the trigger sensor 3 that detects 1 one by one. In addition, as shown in FIG.4 (b), you may provide the multiple lines which rearrange several can products with respect to one packaging apparatus.

  According to the above-described embodiment, it is possible to realize an upside-down can detection technique in which erroneous detection is reduced and the attachment positions and detection timings of sensors are easily adjusted.

(A) shows the schematic structure of the inverted can detection apparatus of this embodiment, (b) is a figure which shows the picked-up image of the bottom face of a can product. (A) shows the schematic structure of the inverted can detection apparatus of this embodiment, (b) is a figure which shows the picked-up image of the upper surface of a can product. It is a block diagram of the inverted can detection apparatus of this embodiment. It is a top view which shows a part of production line by which the inverted can detection apparatus of this embodiment is arrange | positioned, and is a figure which shows the case (a) with a single erect / inverted inspection row | line | column, and the case where there are multiple (b). It is a figure explaining the upside down can detection technique using the conventional fiber sensor. It is a figure explaining the inverted can detection technique using the conventional proximity sensor.

Explanation of symbols

1 Can product 2 CCD camera 3 Trigger sensor 4 Judgment circuit 5 Alarm

Claims (3)

A plurality of can products having different top and bottom shapes are arranged in a line, and the can products that are provided above the transport line in front of the package position for packaging in the case in the same posture are photographed from above. A camera with illumination,
An inverted can detection apparatus comprising: a determination circuit that determines whether the vertical direction of the can product is normal by capturing reflected light from the illumination with the camera and comparing the captured image with a reference image. .   The said can product is provided with the shape part which illumination light does not reflect only in the upper surface, The inverted can detection apparatus of Claim 1 characterized by the above-mentioned.   2. The inverted can detection apparatus according to claim 1, wherein the camera is arranged with a predetermined distance from the can product and an optical axis inclined at a predetermined angle with respect to a horizontal direction.