JPH06186002A - Inspection method for outside appearance of label and its device - Google Patents

Abstract

PURPOSE:To automatically and speedily inspect the inferiority of an outside appearance of a label stuck on an inspected object such as a bottle. CONSTITUTION:A label outside appearance inspection device is composed of a lighting device 3, a television camera 4 and an image processor 5. The inspected portion 2a of a label 2 woundly stuck on a bottle or the like is photographed by the television camera 4, and the profile extraction of a label part and a projection distributing process are carried out on its shadow image by the image processor 5 for automatically judging the inferiority of an outside appearance such as the peeling-off, breakage and hole of the label.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a visual inspection method and apparatus for labels attached to bottles, vials and the like.

[0002]

2. Description of the Related Art Conventionally, there is no effective means for inspecting the appearance of a label attached to a bottle or the like, and almost all rely on visual inspection.

Rarely, as one method of pattern inspection, a bottle or the like is rotated on a turntable so that picked-up images are sequentially input to a determination device. JP-A-56-717
The method described in Japanese Patent No. 8 has been proposed.

Further, as in the method described in Japanese Patent Laid-Open No. 56-7181, a method has been proposed in which a main pattern and a sub-pattern are synchronously input by two cameras and the two are compared.

[0005]

The conventional visual inspection method has a problem in terms of quality and production efficiency because the judgment standard is apt to be ambiguous and erroneous judgment due to eye fatigue is unavoidable. .

Further, in order to always orient the inspection portion of the label at a fixed position in the direction of the camera, the above-mentioned JP-A-56-717 is used.
As seen in the method described in Japanese Patent Publication No. 8, the bottle and the like must be rotated on the turntable, and there is a problem that it cannot be applied when continuously conveyed by a conveyor or the like.

Further, as seen in the method described in Japanese Patent Laid-Open No. 56-7181, there is a problem in that the main and slave two screens must be input for the same inspection purpose and the apparatus becomes complicated.

The present invention has been made in view of the above circumstances, and in order to inspect the appearance of a label attached to a bottle or the like, the inspection site of the subject is captured by a television camera without being fixed to a fixed position. It is an object of the present invention to provide a label appearance inspection method and apparatus capable of automatically and rapidly inspecting a label appearance defect such as label tearing, turning over, and perforation.

[0009]

A label appearance inspection method of the present invention is a label appearance inspection method for inspecting the appearance of a label attached to a body of a subject such as a transparent bottle so as to be wrapped around the body of the subject. From this, irradiate light to the subject, and image the inspection site of the label winding single part of the subject, and only the outline portion of the shadow image of the label in the inspection site of the subject by the imaged transmitted illumination light. It is characterized in that the image processing is performed so as to perform the emphasis extraction, and the label attachment position and the appearance defect are determined based on the image processing result.

Further, the label appearance inspection method of the present invention obtains a projection distribution intensity diagram obtained by projecting a contour extraction image of a shadow image of the label at the inspection portion of the subject in the cylindrical axis direction of the subject, 2 on the distribution intensity map
Two locations of the object outer shape portion and a label wrapping end portion 2 which are provided with thresholds for the locations and which exceed the lower threshold and reach the upper threshold
It is characterized in that the presence or absence of the peak value of the distribution intensity is measured at a total of four places and the quality of the label appearance is judged based on the measurement result.

Further, the label appearance inspection method of the present invention obtains a projection distribution intensity diagram obtained by projecting a contour extraction image of a shadow image of the label in the inspection region of the subject in the cylindrical axis direction of the subject, 2 on the distribution intensity map
Threshold values are set for the locations, and the external shape portions of the subject 2 and the label winding end portion 2 that exceed the lower threshold value and reach the upper threshold value
In addition to the positions showing the peak values at a total of 4 places, the presence or absence of a distribution line showing the intensity above the lower threshold and below the upper threshold is measured, and the quality of the label appearance is judged based on the measurement result. It is characterized by doing.

The label appearance inspection apparatus of the present invention is a label appearance inspection apparatus for inspecting the appearance of a label attached to a body of a subject such as a transparent bottle so as to be wrapped around the body of the subject. Illuminating means for irradiating light, a television camera facing the illuminating means on the inspection site side of the label winding end of the subject, and an image of the inspection site of the subject, and an image captured by the television camera. The image signal indicating the shadow image of the label at the inspection region of the subject by the transmitted illumination light is captured, and image processing is performed so as to emphasize and extract only the outline portion of the shadow image of the label, and based on the image processing result. Image processing means for discriminating a label sticking position and a defective appearance.

Further, the label appearance inspection apparatus of the present invention is a label appearance inspection apparatus for inspecting the appearance of a label attached so as to be wrapped around a body part of a subject such as a transparent bottle. A plurality of television cameras for imaging the circumference, a plurality of illumination means for facing the plurality of television cameras and irradiating light to the subject from the side of the subject, and the plurality of televisions A video signal showing a shadow image of the label of the subject captured by a camera is taken in, and a video signal of a television camera that captures the inspection portion of the label winding end portion of the subject is selected from among these to select the shadow image of the label. Image processing means for performing image processing so as to emphasize and extract only the contour portion of the image, and image processing means for determining a label sticking position and a defective appearance based on the image processing result. The features.

Further, the label visual inspection apparatus of the present invention is characterized in that the plurality of television cameras and the illumination means are dispersedly arranged at a plurality of locations with respect to the passage of the subject.

Further, in the label visual inspection apparatus of the present invention, the plurality of television cameras and the illuminating means are one of the passages of the subject.
It is characterized in that it is arranged radially at a location.

Further, the image processing apparatus of the present invention obtains a projection distribution intensity diagram obtained by projecting a contour extraction image of a shadow image of a label in the examination region of the subject in the cylindrical axis direction of the subject, The peak value of the distribution intensity at a total of 4 places is set on the distribution intensity diagram, with the upper and lower two thresholds being exceeded, and the upper and lower thresholds being exceeded, two places on the outer shape of the subject and two label winding ends. The presence or absence of
It is characterized in that the quality of the label appearance is judged based on the measurement result.

Further, in the label appearance inspection apparatus of the present invention, the image processing apparatus obtains a projection distribution obtained by projecting a contour extraction image of a shadow image of the label in the inspection region of the subject in the cylindrical axis direction of the subject. An intensity diagram is obtained, two threshold values are provided on the upper and lower sides of the distribution intensity diagram, two locations on the outer shape of the subject that exceed the lower threshold and reach the upper threshold, and two locations on the label winding end, for a total of four locations. In addition to the position showing the peak value of the distribution intensity of, the presence or absence of the distribution line showing the intensity above the lower threshold and below the upper threshold is measured, and the quality of the label appearance is judged based on the measurement result. Is characterized by.

That is, according to the present invention, the inspection site of the object such as a bottle, that is, the label winding end is conveyed in substantially the same direction, for example, the inspection site is caught by a conveyor or the like located immediately after the labeling machine. The TV camera is placed on the side and the lighting device is placed on the side opposite to the camera.

The subject is made to pass between the illuminating device and the camera, the image of the inspection region is input to the television camera as a shadow image by transillumination, and only the contour portion is emphasized from the shadow image by the image processing device. The extracted contour extraction image is created.

A window of the judgment area is set so as to slightly overlap the upper and lower portions of the contour extraction image, and the contour extraction image in this window is projected in the cylindrical axis direction of the subject to obtain a projection distribution intensity map. .

A lower threshold value is set at a position lower than the distribution intensity appearing in the case of a defective label appearance product on the above distribution chart,
Furthermore, in the case of non-defective products, the upper threshold value is set to a position as high as possible that satisfies the non-defective product regions of the two distribution diagrams that appear at the label winding end.

By measuring the intensity and the number of distribution lines appearing between the upper and lower thresholds, it is possible to discriminate appearance defects such as oblique sticking, turning over, tearing, and perforation of the label.

The bottle as the subject is an ampoule,
The present invention is applied as it is to a label which is a transparent body such as a vial or a test tube and which is attached so as to be wrapped around the outer periphery. However, the label material may be a material that is less likely to transmit light than a bottle or the like, and may be a shadow image having an appropriate contrast.

[0024]

According to the present invention, the inspection portion of the label is imaged by the television camera at a position where the inspection portion is oriented substantially toward the television camera while the subject such as the bottle is being moved by the transport mechanism such as the conveyor.

In the image picked up by the television camera, the inspection portion of the label becomes a shadow image by the transmitted illumination light from behind.

Since the shadow image on the front side of the subject is large and the shadow image on the back side is small due to the lens angle of view of the TV camera, the shadow image on the back side is captured between the label winding ends on the front side.
The shadow of the label on the back side overlaps, and the image of the inspection site becomes a concave shadow image.

An image in which only the outline of the shadow image is extracted is obtained, and a projection distribution intensity diagram is obtained in the axial direction of the subject from the contour image. If the subject is a non-defective item, two outline contour lines of the subject are obtained. Then, a strong distribution line appears on both sides of the concave shadow image, that is, two label winding ends, that is, four in total.

If the appearance of the label has defects such as turning, tearing, perforation, etc., a diagram with distribution intensity appears at positions other than the above four strong distribution lines.

[0029]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a configuration of an embodiment of a label visual inspection apparatus according to the present invention, in which an illuminating device 3 is arranged on a side of a subject 1 such as a bottle and attached so as to be wound around a body. At a position where the winding end 2a of the label 2 is on the camera 4 side, the illumination light passes through the subject 1, and the label 2 and the inspection portion 2a of the label are imaged by the television camera 4 as a shadow image. The signal is input to the image processing device 5.

Since label appearance defects such as label flipping and tearing mainly occur at the label winding end 2a,
The input image at the winding end is analyzed to determine the quality of the label appearance.

FIG. 2 shows an example of a non-defective image in which the input image of the label winding end portion 2a input by the above method is processed by the image processing device 5 to obtain a light and shade. The image 11 of the subject and the front side image are shown. The label image 21 and the label image 22 on the back side are overlapped as shown in the figure.

FIG. 3 shows an example of a grayscale processed image of a defective product obtained in the same manner as in FIG. 2. If the label has a defective external appearance, images such as a curl 23, a tear 24, and a hole 25 are formed. Becomes

FIGS. 4 and 5 are contour extraction images in which only the contour portion is emphasized and extracted from the grayscale processed images of FIGS. 2 and 3, and FIG. 4 shows an example of a good product and FIG. 5 shows an example of a defective product.

The contour image 12 of the subject, the upper contour image 26 of the label and the lower contour image 27 of the label are extracted as a diagram as shown in the figure, and only the contour portion is extracted.

If the label has a defective appearance, the turning portion 23a, the tearing portion 24a, and the perforated portion 25 correspond to those in FIG.
It becomes a contour diagram like a.

In order to determine the quality of the label appearance from the contour extraction images shown in FIGS. 4 and 5, determination regions 6a and 6b are provided, and a vertical distribution distribution intensity map of the contour extraction image in the determination region is obtained. An example of the determination area 6a will be shown below, but the determination area 6b is also determined by the same method.

FIGS. 6 and 7 are projection distribution intensity charts obtained respectively for the judgment area 6a in FIGS. 4 and 5 as described above. FIG. 6 shows an example of a non-defective product and FIG. 7 shows an example of a defective product. ing.

If it is a non-defective product, as shown in FIG. 6, the projection distribution map of the contour diagram 12 of the subject of FIG. 4 becomes 12a, and the projection distribution diagram of the label winding end contour diagram 2b becomes 2c. . In the case of a defective product, as shown in FIG. 7, the contoured portion 23a of the defective product contour diagram shown in FIG. 5 shows the projected distribution 23b of FIG.
5a appears as a projected distribution intensity diagram like 25b.

In FIG. 7, a lower threshold L is set at a position lower than the distribution strengths 23b, 24b, 25b which appear when the label appearance is poor, and the two threshold values appearing at the label winding end in the case of the good product in FIG. The upper threshold value U is set at a position as high as possible that satisfies the non-defective area of the distribution line 2c.

By measuring the intensity and the number of distribution lines appearing between the upper and lower threshold values L and U, it is possible to easily discriminate a label appearance defect such as diagonal sticking, turning over, tearing, and perforation of the label. That is, as shown in FIG.
Two on the contour of the subject and two on the winding end of the label
If a total of four projection distribution lines appear across the thresholds L and U, it is determined as a non-defective product, and some of the above four projection distribution maps are missing as shown in FIG. If a distribution intensity that exceeds the threshold L and is equal to or less than the threshold U appears at a position other than the distribution width of the book, it can be easily determined as a defective product.

FIG. 8 shows another embodiment of the label visual inspection apparatus according to the present invention. This embodiment shows a case where the label is not oriented in a fixed direction, for example, on a conveyor. The bottle 1 is conveyed by the conveyor 8 in the arrow direction. The inspection site 2a of the label 2 may face either side. A plurality of television cameras 4a to 4d are radially arranged on the side of the conveyor 8 so as to cover the entire circumference of the label 2 so that the inspection site 2a can be always caught by any of the cameras. Illumination devices 3a to 3d are arranged at positions on the opposite sides of these television cameras 4a to 4d, respectively.

In the embodiment shown in FIG. 8, the inspection position is divided into two parts in the carrying direction, but this is to avoid interference between the camera and the illumination, and the small size is provided at the position where interference is avoided. The cameras may be arranged radially at one location by arranging the illuminating device.

Bottle 1 as a subject in the above structure
Are picked up by the television cameras 4a to 4d, the video signals thereof are analyzed by the image processing device 5, only the video signals of the cameras which picked up the inspection region 2a of the bolt 1 are selected, and the video signals from other cameras are ignored. To be done. In the embodiment shown in FIG. 8, the camera 4a is selected. In the subsequent processing, the quality of the label appearance is determined by the method described with reference to FIGS. 2 to 7, and if it is a defective product, the sorting device 9 rejects it.

In the present embodiment, the case of being conveyed by the conveyor 8 or the like has been described, but a method of passing the label portion of the bottles between the illumination device and the camera may be used.

[0045]

As described above, according to the present invention,
Appearance dimensions of labels attached to bottles and the like, and appearance defects such as label tears and flipping can be reliably and rapidly discriminated in a continuous conveyance state by an ordinary conveyance conveyor or the like.

By automating the visual inspection, the production efficiency and the inspection quality can be improved.

[Brief description of drawings]

FIG. 1 is a perspective view showing the configuration of an embodiment of a label visual inspection device according to the present invention.

FIG. 2 is an explanatory diagram showing an example of a shadow image of a label portion.

FIG. 3 is an explanatory diagram showing an example of a shadow image of a label portion.

FIG. 4 is an explanatory diagram showing an example of a contour extraction image of a label portion.

FIG. 5 is an explanatory diagram showing an example of a contour extraction image of a label portion.

FIG. 6 is an explanatory diagram showing an example of a projection distribution intensity diagram.

FIG. 7 is an explanatory diagram showing an example of a projection distribution intensity diagram.

FIG. 8 is a perspective view showing the configuration of another embodiment of the label visual inspection apparatus according to the present invention.

[Explanation of symbols]

 1 Bottle 2 Label 3 Lighting Device 4 Television Camera 5 Image Processing Device 6a Judgment Area 6a Judgment Area 6b Judgment Area 11 Bottle Contour Image 12 Bottle Contour Image 12a Bottle Contour Projection Distribution Map 21 Label Shadow Image 22 Label Shadow Image 23 Label Turning Image 23 Label Breakup Part image 25 Label perforated part image 26 Label outline image 27 Label outline image

Claims (9)

[Claims] 1. A label appearance inspection method for inspecting the appearance of a label such as a transparent bottle, which is attached so as to be wrapped around a body of a subject, in which light is irradiated from a side of the subject toward the subject, The inspection part at the label winding end of the sample is imaged, and the image processing is performed so that only the outline portion of the shadow image of the label at the inspection part of the subject by the imaged transmitted illumination light is emphasized and extracted. A label appearance inspection method characterized by determining a label sticking position and a visual defect based on a result. 2. A projected distribution intensity map obtained by projecting a contour extraction image of a shadow image of a label in the examination region of the subject in the cylindrical axis direction of the subject, and two upper and lower parts on the distribution intensity map. The threshold value is set, and the presence or absence of peak values of distribution intensity at four locations in total, that is, two locations on the outer shape of the subject and two locations on the label winding end that exceed the lower threshold and reach the upper threshold, are measured. The label appearance inspection method according to claim 1, wherein the quality of the label appearance is judged based on the result. 3. A projected distribution intensity map obtained by projecting a contour extraction image of a shadow image of a label in the examination region of the subject in the cylindrical axis direction of the subject, and two upper and lower parts on the distribution intensity map. The above lower threshold value is set in addition to the positions showing the peak values at a total of 4 points of the outer shape part of the subject and the label winding end portion which exceed the lower threshold value and reach the upper threshold value. The label appearance inspection method according to claim 1, wherein the presence or absence of a distribution line that exceeds the threshold value and has an intensity equal to or lower than the upper threshold value is measured, and the quality of the label appearance is determined based on the measurement result. 4. A label appearance inspection apparatus for inspecting the appearance of a label, such as a transparent bottle, which is attached so as to be wrapped around a body of a subject, and a lighting means for irradiating light to the subject from the side of the subject. A television camera arranged on the inspection site side of the label winding end of the subject facing the illuminating means and capturing an image of the inspection site of the subject; and the subject covered by the transmitted illumination light imaged by the television camera. A video signal showing the shadow image of the label at the inspection site of the sample is taken in, image processing is performed so as to emphasize and extract only the outline portion of the shadow image of the label, and the label attachment position and appearance defect based on the image processing result. A label visual inspection device, comprising: 5. A label appearance inspection apparatus for inspecting the appearance of a label attached to a body of a subject such as a transparent bottle so as to be wrapped around the body of the subject, and a plurality of units for imaging the entire circumference of the label attached to the subject. And a plurality of illumination means for facing the plurality of television cameras and irradiating light toward the subject from the side of the subject, and the subject imaged by the plurality of television cameras The video signal showing the shadow image of the label is taken in, and the video signal of the television camera that has imaged the inspection site of the label winding end of the subject is selected from among these to emphasize and extract only the outline portion of the shadow image of the label. And an image processing unit that determines the label attachment position and the appearance defect based on the image processing result. . 6. The label appearance inspection apparatus according to claim 5, wherein the plurality of television cameras and the illumination means are arranged in a distributed manner at a plurality of locations with respect to the passage of the subject. 7. The label appearance inspection apparatus according to claim 5, wherein the plurality of television cameras and the illumination means are radially arranged at one location in a passage of the subject. 8. The image processing apparatus obtains a projected distribution intensity map obtained by projecting a contour extraction image of a shadow image of a label on an inspection region of the subject in a cylindrical axis direction of the subject, and the distribution intensity is obtained. Two thresholds are provided on the upper and lower sides of the figure, and a total of 4 places of the outer shape portion of the subject and the label winding end portion that exceed the lower threshold and reach the upper threshold.
The label appearance inspection apparatus according to any one of claims 4 to 7, wherein the presence or absence of a peak value of distribution intensity at a location is measured, and the quality of the label appearance is determined based on the measurement result. 9. The image processing apparatus obtains a projection distribution intensity map obtained by projecting a contour extraction image of a shadow image of a label at an inspection site of the subject in a cylindrical axis direction of the subject, and the distribution intensity is obtained. Two thresholds are provided on the upper and lower sides of the figure, and a total of 4 places of the outer shape portion of the subject and the label winding end portion that exceed the lower threshold and reach the upper threshold.
In addition to the position showing the peak value of the distribution intensity of the location, the presence or absence of the distribution line showing the intensity above the lower threshold and below the upper threshold is measured, and the quality of the label appearance is judged based on the measurement result. The label visual inspection device according to any one of claims 4 to 8, characterized in that.