JP2005037328A - Method and system for misaligned lid detection - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a good article without misaligned lid from being excluded as inferior goods caused by erroneous detection as the misaligned lid in spite of the undeviated position of the lid to the food container. <P>SOLUTION: The misaligned lid detection method is the method for detecting the misaligned lid by irradiating the food container 2 with the light from the light source 9. Two cases are discriminated where the light is received after passing through a gap formed by positional deviation of the lid 3 to the container main body 2 after the irradiation light from the light source 9 transmitted through the food container 2, and the light is received after passing through the different passage, thereby characteristically detecting the misaligned lid 3 to the food container 2. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a lid displacement detection method and a lid displacement detection system for detecting a displacement of a lid made of, for example, aluminum with respect to a colored food container body containing, for example, jelly, and more particularly to a lid displacement detection system. The position of the lid relative to the food container body that prevents the non-defective product from being accidentally rejected as a defective product by detecting that there is a misalignment in spite of no misalignment. The present invention relates to a lid displacement detection method and a lid displacement detection system for detecting displacement.

2. Description of the Related Art Conventionally, a food container body 2 made of plastic or the like having a plate-shaped cup flange portion 14 on the upper portion thereof, such as a plan view in FIG. 2A and a side view in FIG. A technique of welding and packaging is known by heat-sealing the lid 3 made of aluminum or the like to the plate-shaped cup flange portion 14 of the food container main body 2 after being filled in.
Further, in this case, as shown in FIG. 3, when heat sealing is performed while the position of the lid 3 with respect to the flat cup flange portion 14 of the food container body 2 is shifted, the flat cup flange portion 14 and the opening for taking in and out the food are provided. In the portion 4, an exposed portion 15 that is not covered with the lid 3 is generated, and in the food container body 2, the seal of the opening 4 becomes insufficient, and the contents are released from the gap 5 caused by the positional displacement of the lid. It causes spills or alterations. In order to prevent this, as a conventional technique, there is a technique for detecting a positional deviation of the lid with respect to the food container body by irradiating light to the food container body and the lid from a single light source below. It is known (for example, see Patent Document 1).
JP-A-7-128016

  However, since the above prior art irradiates light from a single light source below, it can be used with high accuracy for transparent food container bodies (transparent cups) that easily transmit light. For the colored food container main body (colored cup) that hardly transmits light, the accuracy tends to be slightly lowered.

  In addition, in the colored cup, in order to detect the positional displacement of the lid with respect to the colored cup, a plurality of high-intensity halogen lamps, metal halide lamps, etc. are used, and irradiation is performed from a plurality of directions obliquely below the colored cup. A technique for transmitting light to the system cup can be considered. If this technique is used, even if it is a colored cup, the positional deviation detection of the cover which permeate | transmitted light is attained.

However, when such a colored cup is inspected, it is necessary to lengthen the exposure time by the light source in order to transmit the light to the colored cup, so that strong light hits the cup flange portion of the colored cup. May cause halation (irregular reflection phenomenon), and the imaging device detects light even when the lid is not positioned correctly, that is, when the lid is accurately positioned on the colored cup. In addition, by detecting that there is a gap caused by the positional deviation of the lid, there is a possibility that a non-defective product in which the lid is accurately positioned with respect to the colored cup is also excluded as a defective product.
In some cases, when intense illumination light hitting the cup flange portion of the colored cup is captured by the CCD camera, the pixel (CCD element) is saturated and overflows to the adjacent pixel, resulting in an actual However, there is a possibility that the product may be recognized as a defective product by being recognized as being irradiated with light in a wide range.

In addition, the imaging apparatus detects that a gap is generated due to the positional displacement of the lid even when the lid is positioned accurately on the colored cup other than the gap generated by the positional displacement of the lid. Specifically, this often occurred in the following cases.
That is, as shown in FIG. 3, the cup flange portion 14 has a width of usually 4 to 5 mm, and the positional deviation of the lid 3 with respect to the cup flange portion 14 is as small as about 1 mm as shown in FIGS. It does not cause a problem with the sealing property of the food container body 2 and is almost non-identifiable even when viewed by humans, but it can be said to be a good product, but the lid 3 made of aluminum and the cup flange of the food container body 2 When the portion 14 is sealed by heat welding, the cup flange portion 7 without the lid may be melted by heating and rounded. When light is irradiated to this rounded flange portion 7 of the cup flange, the halation phenomenon is amplified, and it is detected that a position shift larger than the actual position shift of the lid has occurred. There was a risk of recognizing it as a defective product.
In addition, as shown in FIGS. 5 and 6, when the folded tab 6 of the aluminum lid 3 (the portion that protrudes from the outer periphery of the lid to grasp by hand when opening the lid) 6 is insufficient Then, the tab folding part 6 is irradiated with light, and the reflected light hitting the tab folding part 6 enters the CCD camera, and it is mistakenly recognized that the lid 3 is misaligned, and is recognized as a defective product. There was a fear.

  The present invention has been made in view of such problems, and in spite of the fact that there is no positional deviation of the lid with respect to the food container body, a non-defective product with no positional deviation can be obtained by erroneously detecting the positional deviation. An object of the present invention is to provide a lid displacement detection method for detecting positional displacement of a lid with respect to a food container body, which is prevented from being erroneously excluded as a defective product.

  In the present invention, the lid displacement detection method for detecting the positional displacement of the lid with respect to the food container body by receiving the irradiation light from the light source, after the irradiation light from the light source is transmitted through the food container body, By identifying the case where light is received through a gap caused by the positional deviation of the lid with respect to the food container body and the case where the irradiation light from the light source is received through a different path, There is provided a lid displacement detection method characterized by detecting a displacement of a lid with respect to a food container body.

  Further, in the present invention, a process of distinguishing a pixel irradiated with a light amount less than a predetermined light amount value and a pixel irradiated with a light amount greater than the predetermined light amount value is performed, and a light amount less than the predetermined light amount value is irradiated. The pixel exists by recognizing that the pixel has received the irradiation light that has passed through the gap generated by the positional displacement of the lid with respect to the food container body after passing through the food container body. The lid misalignment detection method according to claim 1, wherein the lid misalignment is detected with respect to the food container main body, and the lid misalignment with respect to the food container main body is detected. Yes.

  Further, in the present invention, the lid displacement detection system detects the positional displacement of the lid with respect to the food container body by receiving the irradiation light from the light source, the irradiation light from the light source transmitted through the food container body A function for discriminating between the case where light is received through a gap generated by the positional deviation of the lid with respect to the food container body and the case where the irradiation light from the light source is received through a different path Therefore, the present invention provides a lid misalignment detection system that detects positional displacement of the lid with respect to the food container body.

  As described above, according to the present invention, although there is no positional deviation of the lid with respect to the food container main body, a non-defective product is erroneously excluded as a defective product by erroneously detecting the positional deviation. Can be prevented.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
The lid slip detection device 8 used in the lid slip detection method according to the embodiment of the present invention is lower than the food container 1 having the food container body (colored cup) 2 colored in red or brown. A plurality of (four) light sources 9 such as halogen lamps and metal halide lamps with high brightness, which are irradiated obliquely, and an imaging device (CCD camera) 10 that reads the irradiation light emitted from the light source 9 after passing through the colored cup 2. The information read by the CCD camera 10 is transmitted to detect the light amount value for each pixel (CCD element), and the pixel having the light amount less than the light amount value of 254 and the pixel having the light amount greater than the light amount value of 254, If the light quantity value is less than 254, it is recognized as having passed through the gap 5 caused by the displacement of the lid 3 relative to the colored cup 2 after passing through the colored cup 2 If the amount of light is not less than 254, it is recognized that the other halation has occurred, etc., so that there is a displacement of the lid 3 with respect to the colored cup 2 when there is a pixel having a light amount less than the light amount of 254. The image processing machine 12 that recognizes that the lid 3 is misaligned, and a monitor that displays whether the lid 3 is misaligned with respect to the colored cup 2 by transmitting information about whether the lid 3 is misaligned with the colored cup 2 11 is provided. The monitor 11 and the image processor 12 constitute a data processing unit 13. The reason why the light amount value 254 is used as a reference value for processing is that the optimum exposure time is determined by experiment, and the light amount value 254 passes through the gap 5 caused by the displacement of the lid 3 with respect to the coloring system cup 2. This is because the value is less than 254, and in other cases, it is confirmed that the light quantity value is 254 or more. In the environment where lid displacement detection is performed, light other than the light emitted from the light source 9 (for example, room light) is excluded from the lid displacement detection target. Therefore, the lid displacement detection device 8 is weak, for example, with a light amount value of 100 or less. It has a function of identifying and removing light.

  In the lid displacement detection method according to the embodiment of the present invention, a plurality of light sources 9 such as halogen lamps and metal halide lamps having high luminance are used for the colored cup 2 colored red or brown using the lid displacement detection device 8. Light is transmitted through the colored cup 2 by irradiating from a plurality of directions (four directions) obliquely below the colored cup 2. The irradiation light emitted from the light source 9 passes through the colored cup 2 and is read by the CCD camera 10. Information read by the CCD camera 10 is transmitted to the image processor 12. The image processor 12 detects a light amount value for each pixel (CCD element), and performs a process of distinguishing a pixel having a light amount less than the light amount value of 254 and a pixel having a light amount greater than the light amount value of 254. If the light amount is less than 254, the light passes through the colored cup 2 and is recognized as having passed through the gap 5 caused by the displacement of the lid 3 with respect to the colored cup 2, and is equal to or greater than the light amount of 254. In the case of, it is recognized that it is due to other halation. Information on whether or not the lid 3 has been displaced relative to the colored cup 2 is transmitted from the image processor 12 to the monitor 11, and the monitor 11 displays whether or not the lid 3 has been displaced relative to the colored cup 2. . Thereby, after passing through the colored cup 2, it is possible to accurately recognize the case where the irradiation light that has passed through the gap 5 caused by the positional deviation of the lid 3 relative to the colored cup 2 is received. Can grasp.

A specific example of the lid displacement detection method according to the embodiment of the present invention will be described based on the relationship with the prior art.
As for the exposure time in the conventional lid displacement detection method, the cup type is detected for the exposure time (shutter speed), and the exposure time is automatically set for each type.
In the prior art, the exposure time is 1 × 64 μs to 2 × 64 μs for a transparent cup, 2 × 64 μs to 4 × 64 μs for a white cup, 8 × 64 μs to 12 × 64 μs for a light colored cup (light brown cup), colored The system cup (red, brown cup) was 22 × 64 μs.

  However, in particular, when the exposure time is 22 × 64 μs with the colored cup, the irradiation light from the light source passes through the gap generated by the positional displacement of the lid with respect to the colored cup after passing through the colored cup, and In other cases, i.e., when halation occurs, i.e., when the lid is slightly displaced or when the tab folding portion is not bent accurately, the light intensity value is 254 or more. It was impossible to discriminate between the case where there was a lid displacement and the case of other halation, etc., and it was erroneously detected as a displacement even though there was no displacement of the lid with respect to the food container body.

  In the lid displacement detection method according to the embodiment of the present invention, the exposure time is 6 × 64 μs to 11 × 64 μs with the colored cup, and the exposure time is shorter than the conventional one. Thereby, after the light emitted from the light source passes through the colored cup and passes through the gap caused by the positional deviation of the lid with respect to the colored cup, that is, when the lid is displaced, the light amount value is less than 254. In addition, in other cases, that is, in the case of slight positional deviation of the lid where halation occurs, or in the case where the tab folding portion is not bent accurately, the light amount value is 254 or more. As a result, if only a pixel having a light quantity value of 254 as a threshold value (binarization level) and only a pixel having a light quantity value less than 254 is detected, it is possible to accurately detect the positional deviation of the lid.

It is a figure which shows the lid deviation detection apparatus used with the lid deviation detection method by embodiment of this invention. It is a figure which shows the container for foodstuffs used by embodiment of this invention. It is the schematic which shows the position shift location of the lid | cover detected with the lid | cover displacement detection method by embodiment of this invention. It is the schematic which shows the state of the slight misalignment mistakenly detected with misalignment in a prior art. It is the schematic which shows the state in which the tab folding mistakenly detected with position shift in the prior art is inadequate. It is the schematic which shows the state misdetected as a position shift in a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Food container, 2 ... Food container main body (colored cup), 3 ... Lid, 4 ... Opening, 5 ... Gap caused by misalignment, 6 ... Tab folding part, 7 ... cup flange part without lid, 8 ... lid displacement detection device, 9 ... light source, 10 ... imaging device (CCD camera), 11 ... monitor, 12. ..Image processor, 13 ... data processing unit, 14 ... flat cup flange, 15 ... exposed part

Claims (3)

A lid displacement detection method for detecting a positional displacement of the lid with respect to the food container body by receiving irradiation light from a light source,
When the irradiation light from the light source passes through the food container body and then passes through the gap generated by the positional displacement of the lid with respect to the food container body, and the irradiation light from the light source A lid misalignment detection method, comprising: detecting a positional displacement of a lid with respect to a food container body by identifying a case where light is received through a different path.   A process for separating a pixel irradiated with a light amount less than a predetermined light amount value and a pixel irradiated with a light amount equal to or greater than the predetermined light amount value. After passing through the container main body, the food container main body when the pixel exists by recognizing that the pixel has received the irradiation light that has passed through the gap caused by the positional deviation of the lid with respect to the food container main body The lid displacement detection method according to claim 1, wherein the displacement of the lid relative to the food container body is detected by grasping that the displacement of the lid relative to the food has occurred. A lid displacement detection system that detects positional displacement of the lid relative to the food container body by receiving irradiation light from a light source,
When the irradiation light from the light source passes through the food container body and then passes through the gap generated by the positional displacement of the lid with respect to the food container body, and the irradiation light from the light source A lid misalignment detection system characterized by detecting a positional displacement of a lid with respect to a food container main body by having a function of discriminating when light is received through different paths.

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