JPH02217968A - Label inspecting device - Google Patents

Abstract

PURPOSE:To prevent the generation of malfunction even when timing is slightly shifted due to the speed variation or the like of a conveyer by executing positioning by internal processing. CONSTITUTION:This label inspecting devices is constituted of a video camera 2, an image memory 3, an image processing part 4, the 1st and 2nd sampling pattern memories 5, 6, the 1st and 2nd inspected pattern memories 7, 8, the 1st and 2nd pattern contrasting parts 9, 10, a deviation detecting part 11, and a pattern detecting part 12. The lightness distribution pattern of an image in an inspection line parallel with the relative moving direction of a object to be inspected is obtained by means of the inspection line, and after executing positioning by internal processing, the obtained pattern is compared with a prescribed lightness distribution pattern. Even when the timing is slightly shifted due to the speed variation or the like of the conveyer, the generation of malfunction can be prevented.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a label inspection device, and more particularly, to a label inspection device for containers (glass bottles, plastic bottles, paper packs, etc.).
The present invention relates to an inspection device that can detect abnormalities in the position and type of labels, printed patterns, etc. attached to metal cans, etc.

[Prior Art] As shown in FIG. 6, an example of a conventional label inspection device captures an image G when a bin B being conveyed by a conveyor V comes to a predetermined position in the field of view of a television camera, and displays it on the screen. It is checked whether edges with label L exist in windows W set at six predetermined locations in the window W, and if edges with label L exist in all windows W, the label pasting position is determined to be appropriate. If there is even one window W in which there is no work or nozzle, it is determined that the label pasting position is inappropriate.

In addition, a window M is placed in a predetermined position corresponding to the label.
is set, and if the binarized area value within each window M is outside a predetermined tolerance range, it is determined that the label is dirty or a different type of label.

Note that C is a bar food that displays the type of label L.

[Problem to be solved by the invention] The conventional label inspection device described above has two problems.

The first problem is that the timing for capturing the image G must be appropriate, and if the timing is even slightly off due to speed fluctuations of the conveyor V, malfunctions may occur. In other words, a complicated configuration is required to ensure strict timing.

The second problem is that the size of the window W is set internally. In other words, if the size of the window W is increased, the accuracy of detecting the positional shift of the label L will decrease, and if the size of the window W is decreased, malfunctions will be more likely to occur due to the timing problem mentioned above. be.

Therefore, it is an object of the present invention to prevent malfunctions even if the timing is slightly off due to speed fluctuations of the conveyor, etc., to avoid problems with the size of the window W, and to ensure that the position and type of labels can be adjusted at the same time. The object of the present invention is to provide an inspection device that can perform inspections.

[Means for Solving the Problems] The label inspection apparatus of the present invention includes an imaging means for obtaining an image of a relatively moving inspection object, and an inspection line parallel to the direction of the relative movement set in the screen of the imaging means. pattern comparing means for aligning and comparing the brightness distribution pattern of the image with a predetermined brightness distribution pattern and outputting a position correction amount and/or pattern matching degree; A structural feature of the apparatus is that it includes a determination means for determining the suitability of the position and/or type of label attached to the inspection object.

In addition, in the above, "and/or" means that either one or both may be used. In addition, the term "label" includes not only labels attached to containers (glass bottles, plastic bottles, paper packages, metal cans, etc.), but also anything printed on the container, such as display fields or patterns. .

[Operation] The label inspection device of the present invention uses an inspection line parallel to the direction of relative movement of the inspection object to obtain the brightness distribution pattern of the image on the inspection line, aligns it by internal processing, and then adjusts the image to a predetermined brightness. Since it is compared with the distribution pattern, malfunctions will not occur even if the timing of image acquisition is slightly off.

Further, since a window is not used for inspection of one deviation and one bend, there is no problem with the size of the window. Furthermore, since pattern matching is determined, the type (content) of labels, etc. can be easily inspected.

In addition, the part where the level of the brightness distribution pattern waveform changes suddenly (
Since the edge of the label can be detected from the rising or falling part), by using this as a timing flag, it is possible to form a window on the screen that corresponds accurately to the desired part of the label, making it possible to inspect foreign labels and dirt. You will be able to do this with high precision.

[Examples] Hereinafter, the present invention will be explained in further detail based on Examples. Note that this invention is not limited to this.

In the label inspection apparatus 1 shown in FIG. 1, a video camera 2 monitors a predetermined area between the conveyor L and the conveyor L that conveys the bottles B. That is, images obtained by the video camera 2 are always stored in the image memory 3.

As shown in FIG. 2, the image processing unit 4
The brightness distribution pattern of the image G on the inspection lines SL and S2 parallel to the direction of movement of the bin B is checked.

The brightness distribution pattern when there is no bin B is the backlight (
The brightness distribution is uniform (not shown), but when the bin B enters the screen at the point (-), the brightness of that part becomes even, so the position of the bin B in the screen can be known.

When the bin B comes to approximately the center of the screen, the image processing unit 4 extracts the brightness distribution pattern of the image G on the inspection lines S1 and S2 at that time.

When the label inspection device 1 is in the "specimen mode", the first I! The brightness distribution pattern extracted at the time i] is stored in the first sample pattern memory 5 and the second sample pattern memory 6, respectively, and the brightness distribution pattern extracted from the second time onwards is first stored in the first sample pattern memory 5 and the second sample pattern memory 6. Alignment with the brightness distribution patterns stored in the two-sample pattern memory 6 (alignment of the image portion of bin B. If an uncorresponding portion occurs at the edge, the brightness of the backlight is used. The same applies hereinafter). ? The first sample pattern memory 5 and the second sample pattern memory 6 respectively store the resultant sample pattern memory 5 and the second sample pattern memory 6. When a predetermined number of times is reached, the values stored in the first sample pattern memory 5 and the second sample pattern memory 6 are divided by the predetermined number of times to calculate the uniform lightness, and this is stored in the first sample pattern memory 5.
and stored in the second sample pattern memory 6, respectively. Therefore, by passing a bottle with a correct label pasted at an appropriate position a predetermined number of times, an average brightness distribution pattern that serves as a reference for checking is set in the first sample pattern memory 5 and the second sample pattern memory 6, respectively. The Rukoto.

After setting the above average brightness distribution pattern in "sample mode", switch the inspection device 1 for labels etc. to "inspection mode".
Make it. Then, the image processing unit 4 extracts the brightness distribution pattern of the image G on the inspection lines S1 and S2, and then stores the extracted brightness distribution pattern in the first test pattern memory 7 and the second test pattern memory 8, respectively. let

When the brightness distribution pattern is stored in the first test pattern memory 7, the first pattern cauterization unit 9 determines the position of the brightness distribution pattern stored in the first sample pattern memory 5 and the first test pattern memory 7, respectively. After alignment, the amount of deviation required for the alignment is output to the deviation inspection section 11, and the degree of matching of the patterns is calculated and the degree of coincidence is output to the pattern inspection section 12.

Similarly, the brightness distribution pattern is stored in the second test pattern memory 8.
When the brightness distribution patterns are stored in the second sample pattern memory 6 and the second sample pattern memory 8, the second pattern comparison unit 1O aligns the brightness distribution patterns (tB, 6) stored in the second sample pattern memory 6 and the second sample pattern memory 8, respectively. The amount of deviation required for this is output to the deviation inspection section 11, and the degree of matching of the patterns is calculated and the degree of matching is output to the pattern inspection section 12.

The deviation inspection section 11 detects the deviation h from the first pattern comparison section 9.
The size of the deviation 14 from the first and second pattern comparison parts 10 is compared with a predetermined tolerance value (lateral deviation detection), and the difference between these deviation meters is compared to a predetermined visitor (-) (rotational deviation detection). Then, if both the size of the deviation 111 is within a predetermined tolerance and the difference in the amount of deviation is within a predetermined tolerance, it is determined that there is no horizontal or rotational deviation, and if not, the label is judged to be inappropriate. The determination result is output to a display unit (not shown).

On the other hand, the pattern inspection section 12 compares the matching degree from the first pattern comparing section 9 and the matching degree from the second pattern comparing section 10 with respective predetermined tolerance values (detection of vertical deviation and type difference). Then, if both Jj and Jj are within the allowable value, it is determined that there is no vertical deviation or type difference, and if either of them is outside the allowable value, it is determined that the label is inappropriate, and the determination result is output to a display section (not shown).

For example, when a bottle B with a rotational misalignment of the bell L as shown in FIG. Even if the magnitudes of line S1 and inspection line S2 are within the allowable values, since the signs are opposite, the difference between the two values is outside the predetermined allowable range, so it is determined that the label is inappropriate.

Note that since the brightness distribution pattern of the label L substantially matches that shown in FIG. 2, the degree of matching is within the allowable value, and it is determined that there is no vertical shift or type difference.

Next, if a bottle] 3 as shown in Fig. 4 comes, for example,
Since the sizes of the misalignment openings are all within the predetermined tolerance and the difference in the amount of misalignment is within the predetermined tolerance, it is determined that there is no lateral misalignment or rotational misalignment, but the brightness distribution pattern for the inspection line S1 Since the barcode does not match the one in FIG. 2 in the C portion of the barcode, it is determined that the label is inappropriate.

Furthermore, as shown in FIG. 5, the image processing unit 4 detects an edge E of the label L from a sudden change part of the brightness distribution pattern for the inspection line S1, and sets a predetermined edge E with this point E as a reference position. A window M is formed at a relative position. Then, calculate the binarized area values within these windows M and compare them with the initially set tolerance range. If it is within the tolerance range, there is no abnormality, and if it is outside the tolerance range, it is determined that it is a different label or Sends output indicating that there is dirt or abnormality.

As described above, according to this label inspection apparatus 1, alignment can be easily performed by internal processing, so even if the timing is slightly shifted due to speed fluctuations of the conveyor V, malfunctions will not occur.

Additionally, it becomes possible to simultaneously inspect the label attachment position and type.

As a modified embodiment, an encoder for detecting the amount of movement by the conveyor V, a photoelectric switch for detecting that the bin B has reached a predetermined position, etc. are provided, and these external signals are used as timing flags to determine the brightness distribution pattern. Examples include extracting the timing flag, forming a window, and comparing it with the internal timing flag mentioned above. According to this, it becomes possible to cope with the case where the difference in brightness between the background and the bin B is small and it is difficult to know the position of the bin B in the image from the brightness. Furthermore, from the brightness, bin B and label L
Even in cases where it is difficult to distinguish between the two types, or where there is no label and a barcode C or some other mark is directly attached to the bottle B, the type can be suitably inspected.

1. I mentioned the label inspection, but this inspection is for containers (
It is also possible to print engravings on glass, plastic, paper, metal, etc.

[Effects of the Invention] According to the label inspection device of the present invention, alignment can be easily performed by internal processing, so even if the timing is slightly shifted due to speed fluctuations of the conveyor ~', malfunctions will not occur.

Furthermore, since the window can be formed at an accurate position corresponding to the label, inspection accuracy can be improved.

Furthermore, it becomes possible to simultaneously inspect the position and type of the label.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an embodiment of the label inspection device of the present invention, Fig. 2 is a conceptual diagram showing the screen and inspection line, and Fig. 3 is a conceptual diagram showing the screen and inspection line.
Figure 4 is an external view of a bottle with a misaligned label, Figure 4 is an external view of a bottle with a misaligned label, and Figure 5
The figure is a diagram corresponding to FIG. 2 with a window formed, and FIG. 6 is a conceptual diagram for explaining the method of the conventional label inspection apparatus ff. ...Second test pattern memory...First pattern pair 11α section 0...Second pattern comparison section 1...Misalignment detection section 2...Pattern detection section. (Explanation of symbols) 1... Inspection device for labels etc. 2... Video camera 4... Image processing unit 5... First sample pattern memory 6... Second sample pattern memory 7... 1 Test pattern memory

Claims (1)

[Claims] 1. Aligning an imaging means for obtaining an image of a relatively moving inspection object and a predetermined brightness distribution pattern with an image brightness distribution pattern on an inspection line parallel to the direction of the relative movement set on the screen of the imaging means and a pattern comparison means for comparing and outputting a position correction amount and/or pattern matching degree, and determining suitability of the position and/or type of label attached to the inspection target based on the position correction amount and/or pattern matching degree. What is claimed is: 1. A label inspection device comprising: determination means for determining a label;