JP2004077495A - Visual inspection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a visual inspection device that can increase inspection accuracy and simplify setting of an optical system. <P>SOLUTION: The visual inspection device 12 comprises lighting means 21 for irradiating a PTP film having tablets and a cover film respectively provided with infrared-transparent identification information (seal part and print part), with infrared light from a pocket part side, a CCD camera 22 sensitive to infrared light, and an image processing device 23 for processing an image signal from the CCD camera 22. In the image processing device 23, first binary coding means 29 first create binary image data without consideration to the seal part of the tablet, locate a tablet region, and determine a foreign matter in the tablet region. Second binary coding means 31 next create binary image data without consideration to the print part of the cover film, and determine a foreign matter on the cover film. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention belongs to the technical field including a visual inspection device.

In general, a PTP sheet has a normally transparent packaging film in which a pocket into which a tablet is inserted is formed, and a cover film attached to the packaging film so as to seal the opening side of the pocket. And is constituted by. Before the cover film is attached to the packaging film, tablets such as solid preparations and capsules are put into the pockets. Tablets are stamped, and cover films are printed to distinguish products.

When manufacturing the PTP sheet, it is necessary to perform an appearance inspection such as inspecting the presence or absence of defective products produced due to cracks, chips, or foreign substances attached to the tablet, and an appearance inspection device is used for such inspection. . That is, in this type of visual inspection device, the tablet is irradiated with visible light by the illumination means, and the reflected light is imaged by the imaging means. The video signal output from the imaging means is binarized by the image processing device at a predetermined threshold. Here, for example, when a white tablet is imaged, the surface of the tablet appears bright, and the portion where the cover film and the foreign matter are present in the background appears dark. By setting the threshold value in consideration of the difference in brightness, the background object and the tablet are distinguished and recognized, and the presence or absence of cracks or chips, or the presence of foreign matter, which is a dark part, is determined by the image processing apparatus. Can be determined by:

By the way, in the above-mentioned technology, in order to distinguish identification information such as stamping and printing from foreign matter and cracks or chipping of tablets, a masking process is applied to an area of stamping or printing by an image processing device, or an area value of stamping or printing is used. Inspections are performed by extracting features by using However, in the inspection, when there is a foreign substance or the like in the masked area or the area of stamping or printing, it becomes difficult to detect the foreign substance or the like.

す る と In addition, if the appearance or position of the seal differs due to the inclination of the tablet, or if the position or color accuracy of the seal and printing itself varies, there is a problem that accurate judgment cannot be made.

Further, since the brightness contrast between the tablet and the cover film varies depending on the product type, the color tone of the illumination means is changed for each product type, or a color filter is provided, so that the contrast is set to be large. And the setting of the optical system may be troublesome.

The present invention has been made in view of the above circumstances, and a main object of the present invention is to provide a visual inspection apparatus capable of improving inspection accuracy and simplifying setting of an optical system.

特 徴 The characteristic means that can achieve the above object will be described below. In addition, characteristic actions and effects of each means will be described as necessary.

Means 1. A tablet appearance inspection device, comprising: an illuminating unit that irradiates at least the tablet with light including infrared light; and an imaging unit that has sensitivity to infrared light and images a surface irradiated by the illuminating unit. And an image processing device for processing a video signal output from the imaging means, wherein the image processing device uses the image data obtained by the video signal to identify the identification information attached to the surface of the tablet. A visual inspection apparatus comprising: a determination unit for determining an abnormality in an area where the tablet exists, ignoring the above.

According to the means 1, when the reflected light of the tablet irradiated with the light including the infrared light by the illumination means is imaged by the imaging means having sensitivity to the infrared light, the tablet exists regardless of the color of the tablet. A video signal is output in which the brightness of the tablet itself is higher than the abnormal part in the area. Therefore, it is not necessary to change the illumination color tone or apply a color filter depending on the color of the tablet, and it is possible to simplify the optical setting. The abnormality is a foreign substance, a crack or a chip of a tablet, and the like (hereinafter, the same applies to each means). In the image processing apparatus, the determination unit ignores the identification information regardless of the presence or absence of the identification information (for example, a seal portion formed of a symbol, a character, a pattern, or the like applied to the surface of the tablet). The abnormality in the area where the tablet is present is determined. That is, by ignoring only the identification information, even if there is an abnormality in the area to which the identification information is attached, the abnormality can be detected, and the inspection accuracy can be improved.

Means 2. An appearance inspection device for tablets placed on a transfer conveyor, wherein the illumination unit irradiates at least light containing infrared light to the tablets, and has sensitivity to infrared light, and is irradiated by the illumination unit. An image processing unit that processes a video signal output from the imaging unit, wherein the image processing device uses the image data obtained by the video signal to generate the tablet. A visual inspection apparatus comprising: a determination unit configured to determine an abnormality in an area where the tablet exists while ignoring identification information attached to a surface of the visual inspection device.

According to the means 2, the same operation and effect as those of the means 1 are achieved, so that the appearance inspection of the tablets placed on the transfer conveyor can be performed.

Means 3. The image image data is gray-scale image data related to lightness, and the determining unit determines the gray-scale image data based on a predetermined threshold, wherein the threshold is lower than the brightness of the tablet surface and the identification information. 3. The visual inspection device according to claim 1 or 2, wherein the brightness is set higher than the brightness of the background and abnormal portion of the tablet.

According to the means 3, since the image data is the light and shade image data relating to the brightness, it is possible to make a determination using the brightness. In the determination means, the identification information can be identified with the tablet surface, that is, can be ignored by setting the threshold value lower than the brightness of the tablet surface and the identification information. Further, by setting the threshold value higher than the brightness of the background of the tablet and the brightness of the abnormal portion, it is possible to reliably detect the abnormality while clearly distinguishing the region where the tablet exists from the background.

(4) Means 4. 4. The visual inspection apparatus according to claim 3, wherein the determination unit makes a determination after creating binarized image image data based on the threshold from the grayscale image data.

According to the means 4, since the image image data binarized from the grayscale image data based on the threshold value is created, it is possible to further improve the certainty in distinguishing the tablet from the abnormality in the image.

{Means 5}. The means (3) or (4), wherein the determination unit performs the determination by comparing the area of the connected component having a lower brightness than the brightness of the tablet in an area where the tablet exists with a predetermined determination reference value. Appearance inspection equipment.

According to the means 5, the determination is made by comparing the area of the connected component having a brightness lower than the brightness of the tablet in the region where the tablet exists with a predetermined determination reference value. Therefore, noise or the like having a small area as a low-brightness connected component can be removed, and abnormality can be determined more reliably.

{Means 6}. The visual inspection apparatus according to any one of means 1 to 5, wherein the identification information is given by using an ink having a property of transmitting infrared light.

According to the means 6, since the identification information of the tablet is an ink having transparency to infrared light, the difference in brightness between the identification information and the tablet itself in reflected light upon irradiation with infrared light is used. Extremely small. Similarly, since the identification information of the cover film employs an ink that is transparent to infrared light, the difference in brightness between the identification information and the cover film itself in reflected light when irradiated with infrared light. Extremely small. Therefore, when creating the image data, the identification information can be identified with the tablet or the cover film, that is, it can be easily ignored.

{Means 7}. A PTP packaging machine comprising the visual inspection device according to any one of means 1 to 6.

(4) As in the means 7, the visual inspection device may be provided in the PTP packaging machine.

Hereinafter, an embodiment will be described with reference to the drawings. First, the PTP sheet 1 as an inspection target will be described with reference to FIGS. The PTP sheet 1 has a packaging film 3 in which a plurality of pockets 2 are recessed, and an aluminum cover film 4 attached to the packaging film 3 so as to cover the pockets 2. . Each of the pockets 2 contains one tablet 5. In the present embodiment, the PTP sheet 1 is manufactured in a sheet shape by cutting or punching a strip-shaped PTP film 6 formed from a strip-shaped packaging film 3 and a cover film 4.

{Circle around (5)} On the surface of the tablet 5, there is provided a seal portion 8 as identification information composed of symbols, characters, patterns and the like. In addition, the cover film 4 is provided with a printing unit 9 as identification information similarly composed of symbols and the like. In the present embodiment, an ink or the like obtained by mixing pigments such as iron sesquioxide, titanium oxide, and an edible dye aluminum lake in a vehicle in which shellac is dissolved in an alcohol-based organic solvent such as butanol is used for the seal portion 8. . In addition, as a material constituting the printing unit 9, an ink such as Alcolor VA (trade name) manufactured by Dainippon Ink and Chemicals, Inc. is used. Each of these inks has transparency to infrared light.

The PTP sheet 1 configured as described above is manufactured by a PTP wrapping machine 11 as shown in FIG. 4, and a visual inspection is performed by a visual inspection device 12 provided in the PTP wrapping machine 11. Has become.

That is, the PTP packaging machine 11 can arrange the packaging film 3 wound in a roll shape on the most upstream side. The packaging film 3 is made of a light-transmissive (here, transparent) thermoplastic resin material such as PP (polypropylene) or PVC (polyvinyl chloride). The packaging film 3 is configured to be transported intermittently, and a heating unit 14 and a pocket forming unit 15 are sequentially arranged along a transport path of the packaging film 3. The pocket 2 is formed by the heating means 14 and the pocket forming means 15. A tablet feeding device 16 and a film receiving roll 17 are arranged along the transfer path of the packaging film 3 in which the pocket portion 2 is formed. Each pocket portion 2 of the packaging film 3 reached to the tablet input device 16 is filled with the tablet 5 by the tablet input device 16.

On the other hand, the drawn end of the cover film 4 wound in a roll shape is guided toward the film receiving roll 17. A heating roll 18 can be pressed against the film receiving roll 17, and the cover film 4 is attached to the packaging film 3 by passing between the two rolls 17 and 18 in a heated and pressed state. ing. Thereby, the PTP film 6 in which the tablet 5 is filled in each pocket portion 2 is manufactured. The PTP film 6 is thereafter cut into one PTP sheet by a punching device (not shown).

Next, the appearance inspection device 12 for the PTP film 6 will be described. As shown in FIG. 1, the appearance inspection device 12 includes an illumination unit 21, a CCD camera 22 as an imaging unit, an image processing device 23, a monitor 24, and a keyboard 25.

(4) The illumination means 21 can emit infrared light. The CCD camera 22 has sensitivity in a wavelength region of infrared light emitted from the illumination unit 21. Here, the relationship between the CCD camera 22 and the illumination means 21 will be described. As shown in FIG. 5, the CCD camera 22 and the illuminating means 21 are arranged on the pocket 2 side of the PTP film 6. Then, the infrared light emitted from the illumination unit 21 illuminates the tablet 5 and the cover film 4 through the packaging film 3, and the light reflected from the tablet 5 and the cover film 4 is two-dimensionally imaged by the CCD camera 22. It has become.

At this time, in the image data as a video signal captured by the CCD camera 22, the brightness of the tablet 5 becomes higher than the brightness of the cover film 4 regardless of the color of the tablet 5. Further, the brightness of the foreign matter on the tablet 5 and the crack or chipping of the tablet 5 is lower than the brightness of the tablet 5, and the brightness of the foreign matter on the cover film 4 is lower than the brightness of the cover film 4. Further, the stamped portion 8 of the tablet 5 and the printed portion 9 of the cover film 4 easily transmit infrared light. For this reason, the difference in brightness between the stamped portion 8 of the tablet 5 and the tablet 5 itself is extremely small, and the difference in brightness between the printed portion 9 of the cover film 4 and the cover film 4 itself is extremely small. In the following, foreign substances on the tablet 5, cracks or chips of the tablet 5, and foreign substances on the cover film 4 are collectively referred to as "foreign substances" for convenience.

Next, the electrical configuration of the visual inspection device 12 will be described. As shown in FIG. 1, the image processing device 23 includes an A / D converter 27, a shading correction unit 28, a first binarization unit 29, a first image memory 30, a second binarization unit 31, It comprises a second image memory 32, a third image memory 33, a determination memory 34, a CPU and input / output interface 35, a visual inspection result and statistical data memory 36, a camera timing control means 37, and the like.

The A / D converter 27 converts two-dimensional image data captured by the CCD camera 22 from an analog signal to a digital signal. The A / D-converted image data is subjected to shading correction by the shading correction means 28 according to the data of the shading correction table 38, and then stored in the third image memory 33. In the shading correction, since there is a technical limit in uniformly illuminating the entire imaging range of the packaging film 3 with the infrared light of the illuminating unit 21, the variation in the brightness of the infrared light caused by the difference in the position is considered. This is performed for correction.

At the same time, the data relating to the corrected brightness is binarized by the first binarization means 29 with the first threshold value δ1, and then sequentially stored in the first image memory 30. I have. Thereby, the first binarized image data of the PTP film 6 is formed. The first threshold value δ1 is for determining a foreign substance in an area (tablet area) where the tablet 5 exists including the seal portion 8. As the first threshold value δ1, for example, a value that is lighter than the cover film 4 and the foreign matter that are the background of the tablet 5 and a value that is darker than the tablet 5 and the seal portion 8 are selected. In the present embodiment, the first threshold δ1 is set to a value slightly lower than the brightness of the tablet 5.

Similarly, the data regarding the corrected lightness is binarized by the second binarizing means 31 with the second threshold value δ2, and then stored in the second image memory 32. Second binary image data is formed. The second threshold value δ2 is mainly for determining foreign matter existing in the cover film 4, and a value darker than the cover film 4 and the printing unit 9 is selected. In the present embodiment, the second threshold value δ2 is set to a value slightly lower than the brightness of the cover film 4.

The CPU and the input / output interface 35 execute various image processing programs and other programs while using the contents stored in the memory for determination 34, and send a control signal to the PTP packaging machine 11 or This is for receiving various signals such as operation signals. Thereby, for example, a defective sheet discharging mechanism of the PTP packaging machine 11 can be controlled. Further, the CPU and the input / output interface 35 have a function of transmitting display data to the monitor 24. With this function, it is possible to display binary or grayscale image data, an appearance inspection result, and the like on the monitor 24.

The visual inspection result and statistical data memory 36 stores data such as coordinates of image data, visual inspection result data, and statistical data obtained by statistically processing the visual inspection result data. These appearance inspection result data and statistical data can be displayed on the monitor 24 under the control of the CPU and the input / output interface 35. Further, the CPU and the input / output interface 35 can send a control signal to the PTP packaging machine 11 based on the appearance inspection result data and the statistical data. The keyboard 25 is for inputting settings such as a reference value for quality judgment stored in the judgment memory 34.

The camera timing control means 37 controls the timing at which image data captured by the CCD camera 22 is taken into the A / D converter 27. Such timing is controlled based on a signal from an encoder (not shown) provided in the PTP packaging machine 11, and the CCD camera 22 captures an image every time the PTP film 6 is fed by a predetermined amount.

Next, a specific example in which a defective appearance due to foreign matter is detected together with the procedure of the appearance inspection of the PTP film 6 will be described with reference to FIGS. 6 (a) to (f), 7, and 8. FIG. 6A shows a part of a visual inspection range of the PTP film 6 as a specific example (hereinafter, referred to as a main inspection range P), and a seal portion 8 (“C” in FIG. It is assumed that a tablet 5 provided with a character () is stored, and a foreign substance Dx is attached to the tablet 5. Further, a printing unit 9 (character “123” in the figure) is provided on the cover film 4. It is assumed that foreign matter Dy is attached. The PTP film 6 is imaged by the CCD camera 22, subjected to shading correction, and stored in the third image memory 33. For example, the brightness of the stored image on the line A-A 'in FIG. 6A is high in the tablet area and the area of the cover film 4 and the foreign substance area are low as shown in FIG. 6B.

Next, a routine R1 as shown in the flowchart of FIG. 7 is executed. In the routine R1, the “inspection determination accompanying the first binarization process” is executed by the image processing device 23 (mainly the CPU). First, in step S1, the image processing device 23 forms first binarized image data by the first binarizing means 29 and stores the data in the first image memory 30 (first binary image data). Treatment). That is, assuming that the first threshold value δ1 or more is 1 (bright) and the value less than the first threshold value δ1 is 0 (dark), the data on the line AA ′ in FIG. It is converted into binary image data as shown in FIG.

Next, in step S2, block processing is performed on the first binarized image data stored in the first image memory 30. The block processing includes a process of specifying each connected component for 0 (dark) and 1 (bright) of the binarized image data, and a labeling process for labeling each connected component. Here, the occupied area of each of the specified connected components is represented by the number of dots corresponding to the pixels of the CCD camera 22.

In step S3, the image processing device 23 specifies a connected component corresponding to the tablet 5 including the seal portion 8 from among 1 (bright) connected components obtained from the first binarized image data. The connected component corresponding to the tablet 5 is a connected component including predetermined coordinates, a connected component having a predetermined shape, or a connected component easily corresponding to the tablet 5 by a determination method such as a connected component having a predetermined area, That is, the tablet region can be specified. Accordingly, in the inspection range P, the tablet area J (see FIG. 6D) including the foreign matter Dx is specified.

In step S4, the image processing device 23 calculates the area Sx of the foreign matter in the tablet area. That is, of the connected components of 0 (dark) obtained from the first binarized image data, those which are included in or connected to the coordinates of the tablet area specified in step S3 are extracted, and the area thereof, that is, the area Sx of the foreign matter, is extracted. Ask for. Therefore, in the inspection range P, the area of the foreign matter Dx is calculated.

In step S5, the area Sx of the foreign matter is compared with a predetermined reference value Px. When the area Sx of the foreign matter is smaller than the determination reference value P, the process proceeds to step S6, and a non-foreign matter determination (normal determination) is performed. On the other hand, when the area Sx of the foreign matter is equal to or larger than the determination reference value Px, the process proceeds to step S7, where foreign matter determination (abnormality determination) is performed. Accordingly, in the inspection range P, the area of the foreign matter Dx is compared with the determination reference value Px to determine whether the foreign matter Dx is a foreign matter. As described above, in the routine R <b> 1, after the tablet area is specified, it is determined whether or not there is a foreign substance in the tablet area regardless of the presence of the seal portion 8.

FIG. 8 is a flowchart showing the routine R2. In the routine R2, the “inspection determination accompanying the second binarization process” is performed by the image processing device 23. First, in step S11, the image processing device 23 forms second binarized image data by the second binarizing means 31, and stores the data in the second image memory 32. That is, assuming that 1 (bright) is greater than or equal to the second threshold δ2 and 0 (dark) is less than the second threshold δ2, the data on the line AA ′ is two-dimensional in FIG. The target image is converted into binary image data as shown in FIG.

In step S12, the block processing similar to step S2 is performed on the second binarized image data stored in the second image memory 32.

In step S13, the image processing device 23 calculates the area Sy of the foreign matter. That is, a connected component of 0 (dark) obtained from the second binarized image data is extracted, and its area, that is, the area Sy of the foreign matter is obtained. Therefore, in the main inspection range P, the area of the foreign matter Dy is calculated.

In step S14, the area Sy of the foreign matter is compared with a predetermined determination reference value Py. If the area Sy of the foreign matter is smaller than the determination reference value Py, the process proceeds to step S15, and a non-foreign matter determination (normality determination) is performed. On the other hand, if the area Sy of the foreign matter is equal to or larger than the determination reference value Py, the process proceeds to step S16, where foreign matter determination (abnormality determination) is performed. Therefore, in the inspection range P, it is determined whether or not the foreign matter Dy is a foreign matter by comparing the area of the foreign matter Dy with the determination reference value Py. As described above, in the routine R2, it is mainly determined whether or not there is a foreign substance on the cover film 4 irrespective of the presence of the printing unit 9.

The processes of the above-mentioned routines R1 and R2 are executed in the process of manufacturing the PTP sheet 1, and the processing unit is one PTP sheet. If at least one of the routines R1 and R2 is determined to be foreign, the PTP sheet 1 is determined to be defective and is discharged.

As described in detail above, according to the present embodiment, ink having transparency to infrared light is used for the seal portion 8 of the tablet 5. Therefore, the difference in brightness between the stamped portion 8 and the tablet 5 itself becomes extremely small in the reflected light when the infrared light is irradiated. Further, by setting the first threshold value δ1 to a value slightly lower than the brightness of the tablet 5, regardless of the presence or absence of the stamped portion 8, only the stamped portion 8 is ignored and foreign matter in the tablet area is determined. it can.

In addition, the printing portion 9 of the cover film 4 is made of an ink having a transmittance to infrared light as in the case of the seal portion 8, so that the reflected light when irradiating infrared light is used for printing. The brightness difference between the portion 9 and the cover film 4 itself becomes extremely small. Furthermore, by setting the second threshold value δ2 to a value slightly lower than the brightness of the cover film 4, regardless of the presence or absence of the printing unit 9, only the printing unit 9 is ignored and the first threshold δ1 is set. Can be determined even on the cover film 4 which could not be determined. Therefore, it is necessary to apply a mask process to the area of the stamping section 8 and the printing section 9, and unlike the prior art in which it is difficult to inspect the masked area, mask processing is not required, and the stamping section 8 and the printing section 9 are not required. The inspection in the area where the printing unit 9 exists can be performed relatively accurately.

(4) Under infrared light, the brightness of the tablet 5 is higher than the brightness of the cover film 4 regardless of the color of the tablet 5. For this reason, there is no need to change the illumination color tone or apply a color filter depending on the color of the tablet 5, and it is possible to simplify optical settings.

Note that the present invention is not limited to the above-described embodiment, and may be implemented as follows, for example.

(A) In the procedure of the visual inspection, without performing the binarization process in the routine R1, a lightness area equal to or more than the first threshold δ1 is detected, a tablet area is determined from the lightness area, and the first area in the tablet area is determined. The foreign matter determination may be performed for the area of the brightness region less than the threshold value δ1. Similarly, without performing the binarization process in the routine R2, the foreign matter determination may be performed on the area of the lightness area smaller than the second threshold value δ2.

(B) Although the above embodiment does not particularly mention a case where there are a plurality of foreign matters in one inspection area, when there are a plurality of areas Sx and Sy where there is a possibility of foreign matters, the largest foreign matter area May be compared with the judgment reference values Px and Py, or each of them may be compared with the judgment reference values Px and Py.

(C) The routines R1 and R2 do not necessarily need to execute both. If the foreign object is determined in the routine R1, the routine R2 may not be executed. If the foreign object is determined in the routine R2, the routine R1 may be executed. Need not be executed.

(D) In the above embodiment, the present invention is embodied as an appearance inspection apparatus for inspecting the appearance of the PTP film 6, but may be embodied as an apparatus for inspecting the appearance of tablets placed on a transfer conveyor, for example.

(E) A camera that includes infrared light and emits light in a wavelength region other than infrared light, for example, visible light, is employed as the illumination means 21 and a camera having sensitivity only to infrared light as an imaging means. Alternatively, a filter that allows only infrared light to pass may be employed in front of a camera that is sensitive to infrared light.

FIG. 2 is a block diagram illustrating an electrical configuration of the visual inspection device. (A) is a perspective view showing a PTP sheet, (b) is a perspective view showing a PTP film. It is a partial expanded sectional view showing a PTP sheet. It is a schematic diagram which shows the schematic structure of a PTP packaging machine etc. It is a perspective view showing the appearance inspection device in a PTP packing machine. It is a figure for explaining the example in which a foreign material is detected in a visual inspection device, (a) is a top view showing a part of a visual inspection range of a PTP film to which a foreign material adhered, and (b) is a top view. FIG. 7B is a diagram showing the brightness on the line AA ′ of FIG. 6A stored in the image memory of FIG. 6A, and FIG. 6C is a diagram of FIG. 6B binarized by the first binarizing means; FIG. 6D shows binarized image data along the line AA ′, and FIG. 6D shows binarized image data of the two-dimensional image of FIG. 6A binarized by the first binarizing means; FIG. 6E shows the binarized image data on the line AA ′ in FIG. 6B binarized by the second binarizing unit, and FIG. It is the binarized image data of the binarized two-dimensional image of FIG. 9 is a flowchart illustrating a routine of “inspection determination accompanying the first binarization process” executed by the image processing apparatus. 9 is a flowchart illustrating a routine of “inspection determination accompanying the second binarization process” executed by the image processing apparatus.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 ... PTP sheet, 2 ... Pocket part, 3 ... Packing film, 4 ... Cover film, 5 ... Tablet, 8 ... Seal part as identification information, 9 ... Printing part as identification information, 11 ... PTP packaging machine, 12 ... Appearance inspection device, 21. Illumination means, 22. CCD camera, 23. Image processing device, .delta.1 first threshold, .delta.2 second threshold, Px determination standard value, Py determination standard value.

Claims (6)

A tablet appearance inspection device,
Illuminating means for irradiating at least the tablet with light including infrared light,
Imaging means having sensitivity to infrared light and imaging the surface illuminated by the illumination means,
An image processing device that processes a video signal output from the imaging unit,
The image processing apparatus uses the image data obtained by the video signal to ignore the identification information attached to the surface of the tablet, and to determine an abnormality in an area where the tablet exists. A visual inspection apparatus characterized by comprising means. A visual inspection device for tablets placed on a transfer conveyor,
Illuminating means for irradiating at least the tablet with light including infrared light,
Imaging means having sensitivity to infrared light and imaging the surface illuminated by the illumination means,
An image processing device that processes a video signal output from the imaging unit,
The image processing apparatus uses the image data obtained by the video signal to ignore the identification information attached to the surface of the tablet, and to determine an abnormality in an area where the tablet exists. A visual inspection apparatus characterized by comprising means. The image data is grayscale image data related to lightness,
The determining means determines the grayscale image data based on a predetermined threshold value,
The visual inspection device according to claim 1, wherein the threshold value is set lower than the brightness of the tablet surface and the identification information, and higher than the brightness of the background and abnormal portion of the tablet. 4. The visual inspection apparatus according to claim 3, wherein the determination unit makes a determination after creating binary image data from the grayscale image data based on the threshold value. The method according to claim 3, wherein the determination unit performs the determination by comparing an area of a connected component having a brightness lower than the brightness of the tablet in a region where the tablet exists with a predetermined determination reference value. Visual inspection device as described. The visual inspection apparatus according to any one of claims 1 to 5, wherein the identification information is provided by using an ink having a property of transmitting infrared light.

Images