JP2000180380A - Visual inspection apparatus and visual inspection apparatus for ptp sheet and ptp-wrapping machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To grasp a level of focusing as objective data such as numerical values or the like by setting a focusing value operation value for operating a focusing value showing the level of focusing from an image signal of a picked reference figure. SOLUTION: The visual inspection apparatus for a PTP sheet used in a PTP-wrapping machine or the like has a CPU, a monitor, etc., and is constituted to operate and display a focusing value or the like. In step (S) 1, a reference figure such as a line, a point or the like is specified from an image signal of, for example, a CCD camera. When the reference figure is a line, a breadth can be set to a specific range. In S2, a peak value of the image signal of, e.g. the reference line specified in the S1 is obtained in a predetermined manner. In S3, a focusing value is operated on the basis of the peak value. The focusing value for an illumination change or the like change is corrected by a predetermined method. In S4, the focusing value is displayed on the monitor. The focusing value is operated and displayed in real time by repeating the S1-S4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an appearance inspection apparatus for inspecting the appearance of an object to be inspected, and more particularly to an appearance inspection apparatus and a PTP for inspecting the appearance of a PTP sheet.
The present invention relates to a PTP packaging machine having a sheet appearance inspection device.

[0002]

2. Description of the Related Art Conventionally, an appearance inspection apparatus for inspecting the appearance of an inspection object captures an inspection object illuminated by transmission illumination or reflection illumination by an imaging device and binarizes the video data by an image processing device. Processing, differentiation processing, connected component processing, area or length comparison processing, shape comparison processing, etc. The appearance such as presence or absence was inspected. For example, Japanese Patent Application Laid-Open No. 55-32573 discloses a video signal obtained by irradiating a tablet packaged in a plastic film with transmitted illumination and obtained by an image sensor, and a video signal for a normal tablet having no defect stored in a memory. An apparatus is described for comparing and thereby detecting the presence or absence of a tablet and the presence or absence of a chip.

[0003]

However, due to mechanical vibrations caused by the transport mechanism or physical repetition of expansion and contraction due to temperature change, the degree of focusing of the image pickup device is gradually reduced as compared with the initial adjustment. May shift. Further, the focus may be suddenly greatly deviated due to an erroneous operation of an operator, a loosened screw, or the like. If the image is out of focus, even if a normal tablet with no chip is imaged, it will not match the video signal for the tablet with no chip stored in the memory, resulting in a defect, There was a problem to do. Further, not only when the image is out of focus, but also when the image is more accurately focused than at the time of the initial adjustment, the same problem occurs because the image does not match the image stored in the memory.

[0004] In such a case, the operator has no choice but to judge from the degree of reflection of the image displayed on the monitor. Even if a large deviation occurring in a short time can be noticed, a small deviation or a continuous deviation occurs. It was very difficult to notice the slight deviation that occurred. Also, even if you notice a shift, the only way to return the focus to its original state is to adjust it with the sense of a person while watching the image projected on the monitor. It is almost impossible to return, and this has been a major obstacle in performing a stable appearance inspection using an appearance inspection device. The present invention has been made in order to solve the above-described problems, and in a visual inspection device, it is possible to clearly determine whether or not the focus is out of focus, and a visual inspection device capable of reliably returning to the original focus and An object of the present invention is to provide a PTP sheet appearance inspection device and a PTP packaging machine.

[0005]

To achieve the above object, a visual inspection apparatus according to claim 1 illuminates an object to be inspected, an imaging device for imaging the object to be inspected, An image processing device that processes a video signal output from the imaging device, wherein the image processing device focuses on a reference graphic representing a degree of focus from a video signal obtained by capturing a reference graphic by the imaging device. It has a focus value calculation unit for calculating a value.

According to a second aspect of the present invention, in the visual inspection apparatus according to the first aspect, the focus value calculation unit calculates the focus value from a peak value of a video signal of the reference graphic. Is determined.

According to a third aspect of the present invention, there is provided a visual inspection apparatus according to the first or second aspect, further comprising a display device for displaying the focus value.

A visual inspection device according to a fourth aspect is the visual inspection device according to the third aspect, wherein the display device changes the display of the focus value in real time in accordance with a change in focus. It is characterized by.

According to a fifth aspect of the present invention, there is provided a visual inspection apparatus according to any one of the first to fourth aspects, wherein the reference graphic is a straight line.

A visual inspection apparatus according to claim 6 is the visual inspection apparatus according to claim 5, wherein when the width of the line is focused on the light receiving portion of the imaging device with a correct focus, { (Width of one pixel) × 2− (width of one dead portion)}
The width is as described above.

According to a seventh aspect of the present invention, in the visual inspection apparatus according to the fifth or sixth aspect, an image is formed on a light receiving portion of the image pickup device with the line having a correct width. In this case, the width is smaller than {(width of one pixel) × 3}.

An appearance inspection apparatus according to an eighth aspect is the appearance inspection apparatus according to any one of the first to fourth aspects, wherein the reference graphic is a point.

According to a ninth aspect of the present invention, there is provided the appearance inspection apparatus according to the eighth aspect, wherein the width of the point is adjusted when the image is formed on the light receiving portion of the imaging apparatus with a correct focus. (Width of one pixel) × 2− (width of one dead portion)}
The width is as described above.

[0014] The visual inspection apparatus according to claim 10 is
The visual inspection device according to claim 8, wherein a width of the point is less than {(a width of one pixel) × 3} when an image is formed on a light receiving unit of the imaging device with a correct focus. Is characterized by the following width.

[0015] The visual inspection device according to claim 11 is
The visual inspection device according to any one of claims 1 to 10, wherein the illumination device includes an illuminance or brightness control unit that controls the brightness to be constant.

A visual inspection apparatus according to claim 12 is
The visual inspection device according to claim 1, wherein the image processing device includes a focus value correction unit configured to correct a focus value according to brightness of the illumination device. It is characterized by.

Further, the visual inspection apparatus according to claim 13 is:
The visual inspection device according to claim 1, wherein the image processing device includes a focus value correction unit configured to correct a focus value based on an integrated value of a video signal of the reference graphic. It is characterized by having.

A PTP sheet appearance inspection apparatus according to a fourteenth aspect is characterized in that the PTP sheet is inspected by the appearance inspection apparatus according to any one of the first to thirteenth aspects.

According to a fifteenth aspect of the present invention, there is provided a PTP sheet appearance inspection apparatus, comprising: an illumination device for irradiating the PTP sheet; an imaging device for imaging the PTP sheet; and an image for processing a video signal output from the imaging device. In a PTP sheet appearance inspection device having a processing device, the image processing device has a focus value calculation unit that calculates a focus value indicating a degree of focus.

According to a sixteenth aspect of the present invention, there is provided a PTP packaging machine including the PTP sheet appearance inspection apparatus according to the fourteenth or fifteenth aspect.

In the appearance inspection apparatus having such a configuration, the image processing apparatus has the focus value calculation unit for calculating the focus value indicating the degree of focus from the video signal obtained by imaging the reference figure by the imaging apparatus. The degree of focus can be grasped as objective data such as numerical values. Therefore, it is possible to clearly determine whether or not the focus is out of focus, and it is also possible to easily determine whether or not the original focus state can be restored at the time of adjustment.

Further, if the focus value calculation section determines the focus value from the peak value of the video signal of the reference figure, the focus value can be reliably calculated by relatively simple processing. Therefore, the burden on the image processing apparatus is small, and the focus can be constantly monitored. Also, when adjusting the focus, the response of the focus value calculation is good and the adjustment is easy.

Further, if a display device for displaying the focus value is provided, monitoring of the focus value becomes easy. Furthermore, if the display device changes the display of the focus value in real time in accordance with the change in focus, the focus adjustment work becomes particularly easy.

Further, if the reference graphic is a straight line, it is easy to set or set the reference graphic when capturing the reference graphic by the imaging device. In particular, when the imaging device is a one-dimensional imaging device such as a line sensor, it is only necessary that a part of the reference graphic crosses the imaging region, so that precise setting work is not required. Also, if the width of the line of the reference graphic is equal to or more than {(width of one pixel) × 2− (width of one dead zone)} when an image is formed on the light receiving unit of the imaging device with a correct focus. The peak value of the video signal of the reference graphic does not depend on the position where the image is formed on the light receiving section of the reference graphic. Therefore, the setting of the reference graphic is further facilitated. In addition, if the width of the line of the reference graphic is less than {(width of one pixel) × 3} when the image is formed on the light receiving unit of the imaging device with the correct focus, the deviation of the focus can be reduced. The video signal responds with high sensitivity.
In particular, since the peak value of the video signal is reliably reduced even with a small defocus, the defocus can be detected with high sensitivity.

If the reference graphic is a point, it is easy to set or set the reference graphic when the image is taken by the imaging device. In particular, when the image pickup device is a two-dimensional image pickup device, it is sufficient that the reference graphic is within the image pickup area, so that precise setting work is not required. Further, if the width of the point of the reference graphic is not less than {(the width of one pixel) × 2− (the width of one dead zone)} when the image is formed on the light receiving portion of the imaging device with the correct focus. The peak value of the video signal of the reference graphic does not depend on the position where the image is formed on the light receiving section of the reference graphic. Therefore, the setting of the reference graphic is further facilitated. Also, when the point width of the reference graphic is focused on the light receiving unit of the imaging device with the correct focus, {(width of one pixel) ×
If the width is less than 3}, the video signal responds with high sensitivity to the focus shift. In particular, since the peak value of the video signal is reliably reduced even with a small defocus, the defocus can be detected with high sensitivity.

Further, if the illuminating device is provided with an illuminance or brightness control unit for controlling the brightness so as to be constant, the video signal of the reference figure, in particular, the signal level or the signal peak level depends only on the focus. Therefore, it is not necessary to consider the luminance of the lighting device, and the calculation of the focus value becomes easy. In addition, if a focus value correction unit that corrects the focus value based on the brightness of the lighting device is provided, the brightness of the lighting device may change due to aging of the lighting device, or fluctuations in power supply, or changes in temperature. It is possible to prevent an influence on the focus value such as a change or disturbance light. In addition, if the focus value correction unit corrects the focus value based on the integral value of the image of the reference graphic, the integrated value of the image of the reference graphic accurately reflects the lighting device and disturbance light.
Accurate correction can be made.

Further, if the PTP sheet is inspected by an appearance inspection apparatus having a focus value calculation unit for calculating a focus value,
The PTP sheet and the tablets or capsules packaged in the PTP sheet can be inspected stably. Also,
A PTP packaging machine is provided with a visual inspection device having a focus value calculation unit for calculating a focus value from a video signal of a reference graphic.
If a PTP sheet appearance inspection device for inspecting P sheets is provided, a PT with the function of stably inspecting product quality
A P packaging machine can be provided.

[0028]

Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, as shown in FIG. 2, the appearance inspection of the PTP sheet is performed in the PTP packaging machine 30 by equipping the PTP packaging machine 30 with a PTP sheet appearance inspection device.

First, a brief description will be given of the PTP packaging machine 30 in which the appearance inspection of the PTP sheet is performed. PTP
The packaging machine 30 is for automatically packaging tablets and the like on a PTP sheet. Specifically, first, polypropylene, P
The container film 40 such as VC is fed into the heating plate 50 and the forming plate 51 by the film feed roll 33 and the tension rolls 31 and 32, and the pocket portion 44 (see FIG. 3) filled with tablets and the like is formed on the container film 40. Molding. When the pocket film 44 (see FIG. 3) 41 formed on the container film 40 is sent to the position below the tablet input shutter 52, the tablet input shutter 52 is moved to each pocket portion 44 (see FIG. 3). Is automatically filled with tablets. Here, the tablet 1 is placed in each pocket 44 (see FIG. 3).
Is filled.

Further, an aluminum sealing film 42 is fed via tension rolls 34 and 35 onto a container film 41 in which each pocket portion 44 (see FIG. 3) is filled with the tablet 1, and a pair of seal rolls is provided. Fix at 36. Thus, a film-like PTP sheet 43 in which the tablet 1 is filled in each pocket portion 44 (see FIG. 3) is manufactured. After the film-shaped PTP sheet 43 is cut into a sheet shape, it is sequentially sent to a not-shown defective sheet discharging mechanism, a PTP sheet stacking mechanism, and the like.

Next, a PTP sheet appearance inspection apparatus will be described with reference to the block diagram of FIG. The visual inspection device includes a CCD camera 11 as an imaging device, a monitor 25 as a display device, an illumination device 12 not shown in the block diagram of FIG. 4, but an illumination device, an image processing device 10, and the like. Note that the CCD camera 11 and the illumination 12 are
Although FIG. 3 shows the inside of the PTP packaging machine 30, it is one of the components constituting the visual inspection device. The illumination 12 is a halogen lamp, a fluorescent lamp having a high-frequency lighting device, or the like. If the illumination has a luminance control unit that can maintain a constant luminance by controlling the temperature of the lamp and the like, the power supply current, and the like, the luminance variation of the illumination 12 is considered in the calculation of the focus value later. Without this, it is possible to calculate the focus value with high accuracy.

The image processing apparatus 10 includes an A / D converter 3, a shading correction unit 14, an image memory 16, a shading correction table 18, a CPU 20, and a determination memory 2.
2, an input / output interface 23, a visual inspection result and statistical data memory 24, a camera timing control means 26, and the like. The A / D converter 3 is a CCD camera 1
The one-dimensional image data captured in step 1 is converted from an analog signal to a digital signal. Where CCD
Describing the camera 11, as shown in FIG. 3, the PTP sheet 43 is illuminated by the light 13 of the illumination 12, and the PTP sheet 43 is one-dimensionally imaged in its width direction. Therefore, a plurality of pockets 44 formed in a line in the width direction of the PTP sheet 43 and the tablets 1 filled in the respective pockets 44 can be simultaneously imaged. At this time, since the PTP sheet 43 in close contact with the fixed roll 37 is imaged, the film-shaped PTP sheet 43 does not swing and does not adversely affect the imaging.

Referring back to FIG. 4, the image memory 16 sequentially stores the A / D converted one-dimensional image data,
This is stored as two-dimensional image data of the sheet. Before the one-dimensional image data is stored in the image memory 16, shading correction is performed by the shading correction unit 14 in accordance with the data in the shading correction table 18. Shading correction is PTP
Since there is a technical limit in uniformly illuminating the entire sheet 43 with the light 13 of the illumination 12, the variation in the brightness of the video data caused by the brightness of the illumination due to such a difference in position is corrected. Therefore, the in-focus value is not adversely affected by variations in the position of the reference line, deviation, and the like.

The CPU 20 is for executing various image processing programs, and is executed using the determination memory 22 or the like. The input / output interface 23 is
This is for transmitting or receiving a control signal to the TP packaging machine 30. Thereby, for example, a defective sheet discharging mechanism of the PTP packaging machine 30 can be controlled. It is also for transmitting display data to the monitor 25, and the monitor 25 can display two-dimensional image data, an appearance inspection result, a focus value, and the like.

Visual inspection result and statistical data memory 24
Stores the appearance inspection result data and statistical data obtained by probabilistically processing the appearance inspection result data. These appearance inspection result data and statistical data can be displayed on the monitor 25. Further, a control signal can be transmitted to the PTP packaging machine 30 based on the appearance inspection result data and the statistical data. The camera timing control means 26 controls the timing at which one-dimensional image data captured by the CCD camera 11 is taken into the A / D converter 3. Such timing is performed based on a signal from an encoder (not shown) provided in the PTP packaging machine 30.

Next, the reference graphic will be described. In the present embodiment, a reference plate, which is drawn with one straight line having a constant width as a reference line, is a CCD which is a one-dimensional image sensor.
It is installed so as to be orthogonal to the arrangement of the pixels of the camera 11 and to be substantially the same height as the inspection object. For the color of the reference figure, it is suitable that the color of the reference graphic is drawn with a high lightness color such as white on a low lightness background such as black in the case of reflective illumination, and a high transmittance on a low transmittance background in the case of transmissive illumination. A figure drawn by colorless and transparent is most suitable. However, in the case of reflective lighting, a reference figure with a low brightness such as black is drawn on a background with high brightness such as white, and in the case of transmissive lighting, a reference figure with low transmittance is drawn on a background with high transmittance. Although it is possible to calculate the focus value from the negative peak value, it is possible, but in the case of reflected light, the difference between the brightness of the background and the reference figure is large, and in the case of transmitted illumination, Those having a large difference in transmittance between the background and the reference graphic are suitable.

The reference figure is a point, more precisely a small circle,
A quadrangle, a polygon, or the like may be used, but if it is a straight line, when the imaging device is a one-dimensional image sensor as in this embodiment, C
There is no effect on the focus value due to the displacement of the reference graphic installation position in the direction orthogonal to the arrangement of the pixels of the CD camera. However, if the angle between the straight line of the reference graphic and the arrangement of the pixels of the CCD camera changes, the width of the line viewed from the CCD camera changes, which affects the calculation of the focus value afterward. Therefore, this angle must always be constant, and is most suitable for setting and managing a right angle. However, if the angle of the reference graphic is calculated and corrected, the angle need not be constant.
When the imaging device is a two-dimensional image sensor, the figure of the reference point is preferably a point, particularly a small circle. Since it is not necessary to consider the angle as in the case of the line, the setting of the reference graphic is further facilitated.

Next, the size of the reference graphic will be described. First, the width of the reference graphic and the change in the video level due to the defocus will be described with reference to FIG. Each pixel constituting the light receiving element has a light receiving portion that receives light and a dead portion that does not respond to light as a space such as a wiring, but for convenience, it is assumed that there is no dead portion in the pixel.

First, when the subject is in focus,
A case where one pixel, that is, a reference line having a width of one pixel on the light receiving element forms an image at the center of the pixel will be described. When the focus is correct, one pixel
00% of the light gathers. When out of focus, light scatters around. When a simplified one-dimensional model is considered, assuming that each pixel is dispersed by 25% on the left and right pixels, the light quantity of the central pixel drops to 50%.

Next, when the focus is accurately adjusted, a reference line having a width of two pixels, that is, {(width of one pixel) × 2}, on the light receiving element is centered on a break between the pixel and the pixel. Will be described. When the subject is in focus, an image is formed on each of the two pixels as 100% light. On the other hand, if the focus is out of focus, assuming that the light is distributed to the left and right pixels by 25%, the light quantity of the central pixel is reduced to 75% since there is no substantial decrease in the light quantity between the two central pixels. Become.

Further, when the subject is in focus,
A case will be described where a reference line having a width of three pixels, that is, {(width of one pixel) × 3}, is formed on the light receiving element such that the center coincides with the center of the pixel. In this case as well, when the focus is correctly adjusted, images are formed on the three pixels as 100% light, respectively. On the other hand, when the focus is shifted, if the light is dispersed by 25% to the left and right pixels, there is no substantial decrease in the light amount between the central three pixels. Remains.

That is, when the width of the reference graphic is accurately focused and the width of three pixels or more on the light receiving element is small, for example, the blur of the formed image is within the range of one pixel. The focus shift is not reflected on the peak value of the video signal of the reference graphic. If the number of pixels is less than three, even a small focus shift is reflected in the peak value.

Next, the change of the image level due to the difference between the width of the reference figure and the image forming position on the light receiving element will be described with reference to FIG. As is apparent from FIG. 6, the width of one pixel is obtained by adding the width of one light receiving portion to the width of one dead portion. (Width of one pixel) = (width of one light receiving portion) + (width of one dead portion) (1)

First, when the subject is accurately focused,
The case of a reference line having a width smaller than the width of one dead portion on the light receiving element will be described. Here, the reference line is
Assume that the level of the video signal when the image is completely formed on the light receiving unit is 100%. On the other hand, when the reference line forms an image completely on the dead area, the level of the video signal becomes 0%. Therefore,
In this case, depending on the position on the light receiving element where the reference line forms an image,
It will vary 100%.

Next, when the subject is in focus,
The case of a reference line having a width equal to the width of one pixel on the light receiving element will be described. Here, it is assumed that the level of the video signal is 100% when the reference line forms an image with the center of the light receiving unit coincident with the center. On the other hand, the level of the video signal is 50% when the image is formed such that the center of the reference line coincides with the center of the dead portion. Therefore, in this case, the reference line varies from 50% to 100% depending on the position on the light receiving element where the image is formed.

Further, when the subject is accurately focused, {(width of one pixel) × 2−
(Width of One Dead Section)} The case of a reference line having a width of not less than will be described. Here, when the reference line forms an image with the center of the light receiving unit coincident with the center, the level of the video signal is 1
00%. On the other hand, the level of the video signal when the image is formed with the center line of the reference line coincident with the center of the dead portion is also 1
00%. Therefore, in this case, the peak of the video signal does not vary depending on the position on the light receiving element where the reference line forms an image.

That is, when the focus is correctly adjusted, {(width of one pixel) × 2−
(The width of one dead portion)}, the peak of the video signal does not vary depending on the imaging position on the light receiving element. Therefore, when the width of the reference line is accurately focused, on the light receiving element, {(width of one pixel) × 2- (width of one dead portion)} and {(one If the width is selected within the range of (pixel width) × 3} or less, installation is easy and the out-of-focus is clearly reflected in the video signal. However, in the two-dimensional image sensor, the width of the pixel may be different between the vertical and horizontal,
When using a point as the reference graphic, it is desirable to use a point such as an ellipse or a rectangle whose vertical and horizontal widths correspond to the vertical and horizontal width of the pixel so that each of the vertical and horizontal satisfies the above-mentioned conditions. When using a circular point as the reference figure,
It is determined that the diameter of the reference graphic is {(width of one pixel) × 2- (width of one dead portion)} or more with respect to the larger width of the width of the vertical and horizontal pixels. This is necessary so as not to be affected by the imaging position on the element, and the diameter of the reference figure is {(width of one pixel) × 3} for the smaller of the widths of the vertical and horizontal pixels. The following things,
This is necessary in order to clearly reflect the focus shift in the video signal.

Next, the procedure of the appearance inspection process of the PTP sheet will be described with reference to the flowchart of FIG. The process of the appearance inspection of the PTP sheet is performed in the image memory 1
6 is performed on the two-dimensional gray-scale image.

First, in step (hereinafter referred to as S) 1, a reference figure is specified from the video signal stored in the image memory 16. The reference figure may be specified each time the operator looks at the video data displayed on the monitor. When the position of the reference graphic is determined in advance, a window may be set, and the video in the window may be specified as the reference graphic. If a window is set so that the reference line is continuously or intermittently displayed, the out-of-focus state can be monitored continuously or intermittently. For example, a reference graphic may be drawn on a machine, and the imaging apparatus may always capture an image of the reference graphic as well as the PTP sheet to be inspected. Further, a reference figure may be drawn on the PTP sheet. Further, the reference figure may be automatically specified by a technique such as pattern matching.

The simplest method is to remove the lighter than the reference line from the imaging range so that the lighter than the reference line is not captured when the reference line is picked up. May be substantially omitted. Also, if a video signal of the difference between the video signal after the reference graphic is installed and the video signal before the installation of the reference graphic is used, all video signals other than the reference graphic become 0,
As in the case of removing an object brighter than the reference line from the imaging range, the operation of specifying the reference graphic can be substantially omitted.

Next, in S2, the peak value of the video signal of the reference line specified in S1 is obtained. The peak value may be one, but the reference line may be imaged a plurality of times, and the average of the peak values of each video signal may be set as the peak value, or the largest value may be set as the peak value. When the reference image is a line, the average of the video levels of each part of the line may be set as the peak, and the largest value may be set as the peak value.

Next, in S3, a focus value indicating the degree of focus is calculated from the peak value. As the focus value, the peak value may be directly used as the focus value. However, since a natural number of about two or three digits is generally easy to handle, an appropriate constant is multiplied to make the value easy to handle. In addition, in order to prevent a change in luminance due to deterioration of the illumination 12 or a change in environment such as temperature, or a change in brightness due to a change in disturbance light from affecting the focus value, the focus is adjusted by the luminance of the lighting device or disturbance light. The value may be corrected.
The luminance or disturbance light of the lighting device may be measured by providing a separate sensor.

The correction of the in-focus value may be performed by obtaining the brightness from the area of the video signal of the reference figure.
Specifically, the integral value of the video signal of the reference graphic is proportional to the brightness. Therefore, a value obtained by dividing the integral value of the video signal of the reference pattern as a reference by the integral value of the video signal of the newly captured reference pattern is used as a correction coefficient, and the value obtained by multiplying the peak value by the correction coefficient is corrected. The correction can also be performed by setting the peak value as described above. Next, the focus value is displayed on the monitor 25 in S4. Numerical values may be displayed as they are, or may be displayed in a graph such as a bar graph. In continuous monitoring, monitoring may be performed using a time-series graph.

Further, S1 to S4 or S2 to S4
May be calculated in real time, and further displayed on the monitor 25. If the focus value is monitored continuously or intermittently, a reference value may be provided. If the focus value deviates from the reference value, an alarm may be issued or the machine may be stopped. Further, a drive device such as a motor may be attached to the focus adjustment mechanism of the camera, and an automatic focus adjustment mechanism for adjusting the focus may be provided so that the difference from a target focus value stored in advance becomes zero. For example, if the target focus value is the focus value at the time of the initial setting, the inspection conditions at the time of the initial setting are automatically maintained.

Further, the best focus value which is the focus value in the state where the focus is best may be displayed together with the actual focus value. For example, if the best focus value is stored and displayed by a method such as a peak hold, the best focus value is reset by temporarily resetting the best focus value, and then changing the focus with the state where the focus was best. Is displayed, and the focus is adjusted so that the actual focus value matches the best focus value, it is possible to easily adjust the focus to a state where the focus is best. Further, in this embodiment, the processing after S1 is performed on the two-dimensional grayscale image on the image memory, but the processing after S1 may be performed on one-dimensional video data. If the focus value is calculated each time one line of video data is read, the response of the calculation of the focus value is improved and the focus adjustment work is further facilitated. Furthermore, in this embodiment, the appearance inspection is performed after sealing with the sealing film 42, but it may be performed before sealing with the sealing film, for example, before molding.

[0056]

According to the appearance inspection apparatus of the present invention, the image processing apparatus converts a reference signal from a video signal obtained by capturing an image of a reference figure by an imaging apparatus.
Since the apparatus has the focus value calculation unit that calculates the focus value indicating the degree of focus, the degree of focus can be grasped as objective data such as numerical values. Therefore, it is possible to clearly determine whether or not the focus is out of focus, and it is also possible to easily determine whether or not the original focus state can be restored at the time of adjustment.

Further, if the focus value calculation section determines the focus value from the peak value of the video signal of the reference figure, the focus value can be reliably calculated by relatively simple processing. Therefore, the burden on the image processing apparatus is small, and the focus can be constantly monitored. Also, when adjusting the focus, the response of the focus value calculation is good and the adjustment is easy.

Further, if a display device for displaying the focus value is provided, monitoring of the focus value becomes easy. Furthermore, if the display device changes the display of the focus value in real time in accordance with the change in focus, the focus adjustment work becomes particularly easy.

Further, if the reference graphic is a straight line, it is easy to set or set the reference graphic when capturing the reference graphic by the imaging device. In particular, when the imaging device is a one-dimensional imaging device such as a line sensor, it is only necessary that a part of the reference graphic crosses the imaging region, so that precise setting work is not required. Also, if the width of the line of the reference graphic is equal to or more than {(width of one pixel) × 2− (width of one dead zone)} when an image is formed on the light receiving unit of the imaging device with a correct focus. The peak value of the video signal of the reference graphic does not depend on the position where the image is formed on the light receiving section of the reference graphic. Therefore, the setting of the reference graphic is further facilitated. In addition, if the width of the line of the reference graphic is less than {(width of one pixel) × 3} when the image is formed on the light receiving unit of the imaging device with the correct focus, the deviation of the focus can be reduced. The video signal responds with high sensitivity.
In particular, since the peak value of the video signal is reliably reduced even with a small defocus, the defocus can be detected with high sensitivity.

Further, if the reference graphic is a point, it is easy to set or set the reference graphic when capturing the reference graphic by the imaging device. In particular, when the image pickup device is a two-dimensional image pickup device, it is sufficient that the reference graphic is within the image pickup area, so that precise setting work is not required. Further, if the width of the point of the reference graphic is not less than {(the width of one pixel) × 2− (the width of one dead zone)} when the image is formed on the light receiving portion of the imaging device with the correct focus. The peak value of the video signal of the reference graphic does not depend on the position where the image is formed on the light receiving section of the reference graphic. Therefore, the setting of the reference graphic is further facilitated. Also, when the point width of the reference graphic is focused on the light receiving unit of the imaging device with the correct focus, {(width of one pixel) ×
If the width is less than 3}, the video signal responds with high sensitivity to the focus shift. In particular, since the peak value of the video signal is reliably reduced even with a small defocus, the defocus can be detected with high sensitivity.

Further, if the illuminating device is provided with an illuminance or brightness control unit for controlling the brightness to be constant, the video signal of the reference figure, in particular, the signal level or the signal peak level depends only on the focus. Therefore, it is not necessary to consider the luminance of the lighting device, and the calculation of the focus value becomes easy. In addition, if a focus value correction unit that corrects the focus value based on the brightness of the lighting device is provided, the brightness of the lighting device may change due to aging of the lighting device, or fluctuations in power supply, or changes in temperature. It is possible to prevent an influence on the focus value such as a change or disturbance light. In addition, if the focus value correction unit corrects the focus value based on the integral value of the image of the reference graphic, the integrated value of the image of the reference graphic accurately reflects the lighting device and disturbance light.
Accurate correction can be made.

Further, if the PTP sheet is inspected by an appearance inspection apparatus having a focus value calculation unit for calculating a focus value,
The PTP sheet and the tablets or capsules packaged in the PTP sheet can be inspected stably. Also,
A PTP packaging machine is provided with a visual inspection device having a focus value calculation unit for calculating a focus value from a video signal of a reference graphic.
If a PTP sheet appearance inspection device for inspecting P sheets is provided, a PT with the function of stably inspecting product quality
A P packaging machine can be provided.

[Brief description of the drawings]

FIG. 1 is a flowchart for obtaining a focus value.

FIG. 2 is a block diagram showing the overall configuration of the visual inspection device of the present invention.

FIG. 3 is a perspective view showing a part of the blister sheet packaging machine, showing a part for imaging the appearance of a tablet or capsule filled in a pocket of a PTP sheet being conveyed.

FIG. 4 is a block diagram showing a functional configuration of the visual inspection device of the present invention.

FIG. 5 is a one-dimensional model of a reference graphic width and a change in image level due to a focus shift.

FIG. 6 is a one-dimensional model of a change in image level due to a difference between a reference graphic width and an image forming position on a light receiving element.

[Explanation of symbols]

 Reference Signs List 1 tablet 3 A / D converter 10 image processing device 11 CCD camera 12 illumination 13 light 14 shading correction means 16 image memory 18 shading correction table 20 CPU 22 determination memory 23 input / output interface 24 statistical data memory 25 monitor 26 camera timing control Means 30 PTP packaging machine 31, 32, 34, 35 Tension roll 33 Film feed roll 36 Seal roll 37 Fixed roll 40 Container film 42 Sealing film 43 Blister sheet 44 Pocket 50 Heating plate 51 Molding plate 52 Tablet input shutter 110 PTP sheet 114 Sealing film 115 Pocket part 116 Tablet or capsule 117 Container film

 ──────────────────────────────────────────────────続 き Continuing on the front page F term (reference) 2F065 AA49 BB05 BB11 BB15 CC00 CC02 EE00 EE05 FF10 FF42 FF61 FF63 GG02 GG03 JJ02 JJ03 JJ25 JJ26 NN01 NN18 NN19 PP16 QQ03 QQ14 QQ23 QQ24 QQA QAQ2AQ2AQ2AQ2AQ2AQ2AQ2A2 CA03 DA01 DA06 DA09 EA09 EA11 EA12 EA14 EA23 EB01 EB09 EC02 ED01 ED03 ED07

Claims (16)

[Claims] An appearance inspection apparatus comprising: an illumination device that irradiates an inspection object; an imaging device that images the inspection object; and an image processing device that processes a video signal output from the imaging device. An appearance inspection apparatus, characterized in that the image processing apparatus includes a focus value calculation unit that calculates a focus value indicating a degree of focus from a video signal obtained by capturing a reference graphic by the imaging apparatus. 2. The visual inspection apparatus according to claim 1, wherein the focus value calculation unit determines the focus value from a peak value of a video signal of the reference graphic. 3. The visual inspection device according to claim 1, further comprising a display device for displaying the focus value. 4. The visual inspection apparatus according to claim 3, wherein the display device changes the display of the focus value in real time in accordance with a change in focus. 5. The visual inspection device according to claim 1, wherein the reference graphic is a straight line. 6. When the line width is formed on the light receiving section of the image pickup device with a correct focus, {((width of one pixel) × 2)
6. The visual inspection apparatus according to claim 5, wherein the width is not less than-(width of one dead portion)}. 7. When an image is formed on the light receiving section of the image pickup device with a correct focus, the line width is {(width of one pixel) ×
7. The visual inspection apparatus according to claim 5, wherein the width is less than 3}. 8. The visual inspection apparatus according to claim 1, wherein the reference graphic is a point. 9. The method according to claim 9, wherein the width of the point is {(width of one pixel) × 2
9. The visual inspection apparatus according to claim 8, wherein the width is not less than (the width of one dead portion)}. 10. When the width of the point is formed on the light receiving portion of the imaging device with a correct focus, {(width of one pixel) ×
The visual inspection device according to claim 8 or 9, wherein the width is less than 3}. 11. The visual inspection device according to claim 1, wherein the illumination device has an illuminance or brightness control unit for controlling the brightness to be constant. . 12. The image processing apparatus according to claim 1, wherein the image processing apparatus includes a focus value correction unit that corrects a focus value according to the brightness of the illumination device. Visual inspection device to be described. 13. The image processing apparatus according to claim 1, further comprising a focus value correction unit configured to correct a focus value based on an integrated value of a video signal of the reference graphic. Appearance inspection device described in (1). 14. A PTP sheet appearance inspection apparatus, wherein the PTP sheet is inspected by the appearance inspection apparatus according to any one of claims 1 to 13. 15. An appearance inspection apparatus for a PTP sheet, comprising: an illumination device for irradiating a PTP sheet; an imaging device for imaging the PTP sheet; and an image processing device for processing a video signal output from the imaging device. The PTP sheet appearance inspection device, wherein the image processing device includes a focus value calculation unit that calculates a focus value indicating a degree of focus. 16. A PTP packaging machine comprising the PTP sheet appearance inspection device according to claim 14.