JP4106143B2 - Appearance inspection method and appearance inspection device for tablet blister packaging line - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an appearance inspection method and an appearance inspection apparatus in a blister packaging line for tablets, and more particularly to a technique that makes it possible to discriminate non-defective products from regular tablets that have been determined to be defective.
[0002]
[Prior art]
In the tablet blister packaging line, tablets are accommodated in concave pockets formed in large numbers on a PTP (Press Through Package) sheet, and an aluminum film or the like is adhered to the PTP sheet to seal the pocket. In this line, for example, as disclosed in Japanese Patent Laid-Open No. 10-104076, a tablet in a pocket is imaged with a camera from above, and an image of the obtained tablet is processed to determine whether there is a tablet in the pocket. Check for any. Further, the captured image is subjected to image processing to measure the major axis and minor axis of the tablet, and the measured major axis and minor axis are compared with a preset reference diameter. If either of the measured long diameter and short diameter did not fit within the standard diameter, the tablet was judged to be an irregular shape and handled as a defective product.
[0003]
[Problems to be solved by the invention]
However, some regular tablets contained in the pockets are tilted inside, as shown in FIGS. 4 (a) and 4 (b). In this case, since the tablet is projected in an oval shape on the camera, when the minor axis and the major axis of the tablet image are measured, the minor axis does not reach the reference diameter, and is determined to be an irregular shape. Even if the tablet accommodated in the pocket is sent to the sealing process as it is, it can be sealed in the pocket without any problem with the metal film. That is, conventionally, a regular tablet is contained in a pocket and can be properly sealed, but it is handled as a defective product. For this reason, the number of defective products is increased, the production efficiency is poor, and the manufacturing cost is increased.
[0004]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an appearance inspection method and an appearance inspection apparatus that can determine that a regular tablet stored in a pocket is inclined as a genuine product. It is to be.
[0005]
[Means for Solving the Problems]
The appearance inspection method in the tablet blister packaging line of the present invention is specified by the following items (1) to (7).
(1) It is an appearance inspection method in a tablet blister packaging line, and tablets contained in pockets having a concave cross section formed in large numbers on the surface of a PTP sheet are inspection targets.
(2) The tablet is imaged with a camera arranged above the PTP sheet.
(3) The captured image of the tablet obtained from the camera is subjected to image processing , and the major axis and minor axis of the tablet image are measured.
(4) Compare the measured major and minor diameters with the reference diameter, and if both the measured major and minor diameters are within the standard diameter range, place the tablet corresponding to the tablet image in the pocket correctly. Judged as a regular stored tablet.
(5) When the measured major axis exceeds the upper limit value of the reference diameter, the tablet corresponding to the tablet image is determined to be a first-type variant.
(6) If both the measured major axis and minor axis are less than the lower limit of the reference diameter, the tablet corresponding to the tablet image is determined to be a second type deformed object.
(7) If the measured major axis is within the range of the reference diameter and the minor axis is less than the lower limit of the reference diameter, the difference between the center position of the tablet image and the center position of the pocket is calculated from the captured image , The positional deviation amount of the tablet corresponding to the tablet image is obtained. When the amount of positional deviation of the tablet is less than the predetermined value, the tablet corresponding to the tablet image is determined as the third type of deformed object. On the other hand, when the amount of positional deviation of the tablet exceeds a predetermined value, it is determined that the tablet corresponding to the tablet image is a regular tablet that is stored in an inclined manner in the pocket.
[0006]
An appearance inspection apparatus in the tablet blister packaging line of the present invention is an apparatus used for carrying out the appearance inspection method, and includes the camera and a computer that performs image processing on an image of a tablet obtained from the camera. Prepare.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
=== Outline of Embodiment ===
One embodiment of the present invention is shown in FIG. The PTP sheet 2 is continuously conveyed on the packaging line. The PTP sheet 2 is formed of, for example, a synthetic resin material such as a vinyl chloride material, and a large number of pockets 4 are formed on the surface thereof at intervals along the longitudinal direction and the width direction of the sheet 2. Each pocket 4 is formed to have a concave cross section, has a circular opening, and bulges to the opposite side of the PTP sheet 2. Inside each pocket 4, one disk-shaped tablet 6 having a size slightly smaller than the pocket is accommodated. Each tablet 6 is loaded when the PTP sheet 2 passes through the tablet loading process. Thereafter, the PTP sheet 2 is conveyed to the packaging process, and a metal sheet such as an aluminum film is adhered to the PTP sheet 2 so that the tablet 6 is sealed in the pocket 4. A color camera 8 such as a CCD camera is installed above the PTP sheet 2 and images the state of each pocket 4 and each tablet 6. A captured image of the camera 8 is input to the computer 10. FIG. 2A shows an example of a captured image obtained by the computer 10 from the color camera 8.
[0008]
=== Computer Image Processing ===
The computer 10 captures the output from the color camera 8 into the image processing unit, samples the image of the PTP sheet 2 at a predetermined cycle, and converts it to digital, and converts the digital color image data into density conversion processing, smoothing processing, or binary processing. Pre-processing such as conversion processing is performed as necessary. Next, the tablet part is cut out from the PTP sheet image using a template prepared in advance. Thereby, for example, image data composed of several tablet images 14 as shown in FIG. 2B is obtained. The tablet 6 accommodated in the pocket 4 includes one that is correctly arranged at the center of the pocket 4 and one that is inclined at the end of the pocket 4. Further, the pocket 4 may contain foreign substances such as foreign tablets and dust that should not be originally stored. The image data obtained by cutting out the tablet portion includes these binarized images (referred to as tablet image 14). The computer 10 measures the major axis and minor axis of each obtained tablet image 14 and discriminates them as follows.
[0009]
== Tablet discrimination by computer ===
A processing flow of the computer 10 is shown in FIG. The computer 10 compares the major axis and the minor axis of the obtained tablet image 14 with a preset reference diameter. The reference diameter is a range in which the diameter dimension of a regular tablet to be accommodated in the pocket 4 is determined, and is set in consideration of an allowable error range in the standard dimension of the tablet image of the regular tablet. The reference diameter is registered in advance for each tablet type in the database 12 that is comprehensively managed by the computer 10, and the data is read from the database 12 and set as the reference diameter at the time of inspection.
[0010]
As a result of comparing the major axis and minor axis of the tablet image 14 with the reference diameter, when both the major axis and minor axis of the tablet image 14 are within the range of the standard diameter, the tablet 6 corresponding to the tablet image is selected. It is determined that the tablet is properly stored in the pocket 4 (S101, S102). On the other hand, when the major axis of the tablet image 14 exceeds the upper limit value of the reference diameter, the tablet 6 corresponding to the tablet image 14 is determined to be a first-type variant (S103, S104). As a result, it is possible to discriminate different types of tablets or dust that are larger than regular tablets. If the major axis of the tablet image 14 does not reach the lower limit value of the reference diameter, the tablet 6 corresponding to the tablet image 14 is determined to be a second type deformed object (S105, S106). As a result, it is possible to discriminate a heterogeneous tablet or chip with a chip smaller in size than a regular tablet.
[0011]
On the other hand, when the major axis of the tablet image 14 is within the range of the reference diameter and the minor axis is less than the lower limit value of the reference diameter, the pocket 4 is not limited to a deformed object such as a tablet or dust with a chip. Since it may be a regular tablet stored in a tilted manner, these are discriminated by the following method. As shown in FIGS. 4A and 4B, the regular tablet 6 accommodated in the pocket 4 is inclined and leans against the opening of the pocket 4. Therefore, the center position of the inclined tablet 6 is separated from the center position of the pocket 4 by a certain amount or more. On the other hand, when the tablet 6 that is slightly smaller than the pocket 4 is correctly accommodated in the pocket without being inclined, the center position of the tablet is the center position of the pocket 4 as shown in FIGS. 4 (c) and 4 (d). There is no more than a certain distance, though it may be a little away. If the minor axis is less than the lower limit of the reference diameter and the center position is not more than a certain distance from the center position of the pocket, it is a deformed object such as a tablet or dust with a chip.
[0012]
Therefore, first, the center position of the tablet image 14 is measured by the feature extraction process (S107). Then, the difference between the center position of the obtained tablet image 14 and the center position of the pocket 4 is calculated to determine the amount of tablet displacement. The center position of the pocket 4 is obtained by referring to data set in the database 12 in advance or by determining the center position of the pocket 4 from the image of the pocket 4 included in the image of the PTP sheet by an appropriate feature extraction process. It is examined whether or not the positional deviation amount of the tablet 6 thus obtained is a predetermined value or more (S108). If the positional deviation amount of the tablet 6 is equal to or greater than the predetermined value, it is determined that the tablet 6 corresponding to the tablet image 14 is a regular tablet stored in a tilted manner in the pocket 4 (S110). On the other hand, if the positional deviation amount of the tablet 6 is less than the predetermined value, it is determined that the tablet 6 corresponding to the tablet image 14 is a third type deformed object (S109). Here, the predetermined value serving as a determination criterion is set with reference to the size of the tablet and pocket. As a result, the tablet 6 determined to be a regular tablet stored in a tilted manner in the pocket 4 is handled as a non-defective product in the same manner as a regular tablet correctly stored in the pocket 4.
[0013]
=== Other Embodiments ===
(1) The camera 8 may be a monochrome camera.
(2) The tablet 6 may be either a sugar-coated tablet or a plain tablet as long as it is a disk type.
(3) Two or more kinds of tablets may be accommodated in the PTP sheet 2. In this case, the computer 10 reads the reference diameter data, the pocket center position data, and the like from the database 12 for each tablet, and performs determination processing.
(4) In addition to the major axis and minor axis of the tablet 6, other items may be used as materials for determining whether or not the tablet is a regular tablet.
[0014]
【The invention's effect】
According to the present invention, the major axis and minor axis of the tablet image measured based on the captured image of the tablet accommodated in the pocket of the PTP sheet are compared with the reference diameter, respectively, and the major axis falls within the range of the reference diameter and the minor axis When it is less than the lower limit of the reference diameter, it is processed to determine whether it is a regular tablet that is tilted and accommodated in the pocket. A regular tablet can be judged as a good product. In addition, in this case, the center position of the tablet image is measured to calculate the difference from the center position of the pocket, and the position shift amount of the tablet corresponding to the tablet image is obtained, and this position shift amount satisfies a predetermined condition. Since it is determined that the tablet is a regular tablet only in this case, it is possible to reliably distinguish between a different form such as a heterogeneous tablet or dust and a regular tablet. In this way, since the regular tablets stored in the pocket in a tilted manner can be reliably discriminated, erroneous determination can be reduced and the production efficiency can be improved.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is an explanatory view showing the appearance and schematic configuration of an appearance inspection of an appearance inspection apparatus in a tablet blister packaging line of the present invention.
FIG. 2A is a plan view showing an example of an image of a PTP sheet captured by the camera of the present invention.
(B) It is the top view which showed an example of the image obtained when a tablet part is cut out.
FIG. 3 is a flowchart showing the flow of processing of a computer for determination processing according to the present invention.
FIG. 4A is a longitudinal sectional view showing a state where a regular tablet is stored in a tilted manner in a pocket of a PTP sheet.
(B) It is the upper side figure which showed the mode from the top when a regular tablet inclines and accommodated in the pocket of a PTP sheet.
(C) It is the longitudinal cross-sectional view which showed a mode when a regular tablet was correctly accommodated in the pocket of a PTP sheet.
(D) It is the top view which showed the mode from the upper side when a regular tablet was correctly accommodated in the pocket of a PTP sheet.
[Explanation of symbols]
2 PTP sheet 4 Pocket 6 Tablet 8 Camera 10 Computer 12 Database 14 Tablet image

Claims (2)

Invention specified by the following items (1) to (7).
(1) It is an appearance inspection method in a tablet blister packaging line, and tablets contained in pockets having a concave cross section formed in large numbers on the surface of a PTP sheet are inspection targets.
(2) The tablet is imaged with a camera arranged above the PTP sheet.
(3) The image of the tablet obtained from the camera is image-processed , and the major axis and minor axis of the tablet image are measured.
(4) Compare the measured major and minor diameters with the reference diameter, and if both the measured major and minor diameters are within the standard diameter range, place the tablet corresponding to the tablet image in the pocket correctly. Judged as a regular stored tablet.
(5) When the measured major axis exceeds the upper limit value of the reference diameter, the tablet corresponding to the tablet image is determined to be a first-type variant.
(6) If both the measured major axis and minor axis are less than the lower limit of the reference diameter, the tablet corresponding to the tablet image is determined to be a second type deformed object.
(7) If the measured major axis is within the range of the reference diameter and the minor axis is less than the lower limit of the reference diameter, the difference between the center position of the tablet image and the center position of the pocket is calculated from the captured image , The positional deviation amount of the tablet corresponding to the tablet image is obtained. When the amount of positional deviation is less than a predetermined value, the tablet corresponding to the tablet image is determined to be a third type deformed object. On the other hand, when the amount of positional deviation exceeds a predetermined value, it is determined that the tablet corresponding to the tablet image is a regular tablet stored in an inclined manner in the pocket.   An apparatus used for carrying out the appearance inspection method according to claim 1, comprising: the camera; and a computer that processes an image of a tablet obtained from the camera.

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