JP3549656B2 - Tablet printing equipment - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a tablet printing apparatus having a tablet appearance inspection function and a print inspection function.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, there has been known a tablet printing apparatus having a visual inspection function for inspecting a tablet for cracking, chipping, adhesion of a foreign substance, and the like, and a print inspection function for judging the quality of printing. FIG. 9 shows the configuration of a conventional tablet printing apparatus. In FIG. 9, pockets (not shown) are arranged on the first transport drum 100, and the tablets supplied by the tablet hopper 101 are aligned in each pocket and transported in the direction indicated by the arrow in the figure. A first inspection unit (photographing device) 103 is provided between the tablet hopper 101 and the printing unit 102 in the transport direction of the first transport drum 100, and is provided on a surface (front surface) on which tablets are to be printed. Conduct an appearance inspection for cracks, chips, foreign matter, etc. In addition, a second inspection unit 105 is provided between the printing unit 102 and the second transport drum 104, and determines the quality of printing performed on the surface of the tablet by the printing unit 102. Further, a third inspection unit 106 is provided so as to face the second transport drum 104, and performs a visual inspection of a surface (rear surface) on which tablets are not printed.
[0003]
[Problems to be solved by the invention]
Generally, when inspecting the appearance of a tablet, a pocket portion for conveying the tablet (generally subjected to black alumite treatment) and a tablet (a bright color such as white and yellow, as well as a relatively dark color such as red) are included. Using the contrast ratio of (2), the tablet is determined for cracking, chipping, the presence or absence of foreign matter, and the like. On the other hand, when determining the quality of the printing performed on the tablet, the quality of the printing is determined using the contrast ratio between the color of the surface of the tablet and the color of the ink used for printing. Here, when printing is performed on the tablet, a color having a high contrast and an easy-to-see color is selected as the color of the ink according to the color of the tablet.
[0004]
Therefore, when the color of the tablet is dark in the visual inspection of the tablet, the contrast ratio between the pocket portion and the tablet is low, and the sensitivity of the imaging device that performs the visual inspection of the tablet must be increased or the threshold value of the determination circuit must be lowered. No. On the other hand, when the color of the tablet is bright, the contrast ratio between the pocket portion and the tablet is high, so that it is not necessary to increase the sensitivity of the photographing device for inspecting the appearance of the tablet or to lower the threshold value of the determination circuit. Rather, it is required to increase the threshold of the determination circuit to increase the determination accuracy. On the other hand, in the case of determining whether the printing of the tablet is good or bad, regardless of whether the color of the tablet is light or dark, an ink having a color that increases the contrast according to the color of the tablet is used, It is not necessary to change the sensitivity of the photographing device for inspecting the printing of tablets or the threshold value of the determination circuit much.
[0005]
If the contrast ratio of the color of the pocket and the color of the tablet in the visual inspection of the tablet and the contrast ratio of the color of the tablet and the color of the ink in the printing quality judgment are significantly different, the sensitivity of the imaging device required for the visual inspection of the tablet or The threshold value of the judgment circuit and the sensitivity of the photographing device required for the tablet printing inspection or the threshold value of the judgment circuit are extremely different, and the appearance inspection of the tablet and the quality judgment of printing are performed by the same photographing device and the judgment circuit. Can not. Therefore, in the above-described conventional printing apparatus, it is necessary to use three independent photographing apparatuses for the appearance inspection and the printing inspection of the front and back surfaces of the tablet, respectively, which causes a problem that the apparatus becomes large and the cost of the apparatus increases. Had. When performing double-sided printing of a tablet, a printing unit for printing on the back surface of the tablet and a fourth inspection unit for determining the quality of the printing performed on the back surface are provided on the outer peripheral portion of the second transport drum 104. However, there is a problem that the size of the apparatus is increased.
[0006]
Also, tablet printers using a fiberscope instead of the second inspection unit 105 have been put to practical use in order to reduce the size of the device or because there is no space for installing an inspection unit or an imaging device inside the device. . However, because the field of view of the fiberscope is narrow, tablets conveyed by one fiberscope of It is impossible to inspect all of the tablets, and the fiber scope is periodically translated in the direction of the rotation axis of the first transport drum 100, and the quality of the printing performed on the tablets is sampled and inspected. It is.
[0007]
The present invention has been made in order to solve the problems of the above-described conventional example, and simultaneously performs the visual inspection of the surface on which the tablet is printed and the quality judgment of the printing by using one photographing device, and It is an object of the present invention to provide a tablet printing apparatus in which the required number is reduced and the size of the apparatus is reduced while performing 100% inspection.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the tablet printing apparatus of the present invention is provided with a transport unit that transports at least tablets in a predetermined arrangement state, and is provided so as to face a transport surface of the transport unit, and has a predetermined surface on the tablet. Printing means for performing printing, A first inspection unit that is provided upstream of the printing unit in the transport direction of the transport unit and that performs a visual inspection of a first surface on which the tablets are not printed; Provided downstream of the printing means in the transport direction of the transport means, the tablet of the On the opposite side of the first surface printing But Given Second Perform surface appearance inspection and print inspection simultaneously in parallel Second Including inspection means, Second Inspection means was printed on the tablet The second It has a photographing device for photographing a surface, and a visual inspection circuit and a print inspection circuit for performing visual inspection and print inspection based on output data of the photographing device, respectively.
[0009]
In the above configuration, the visual inspection circuit is printed with the tablet obtained by the imaging device. The second A part where the predetermined pattern stored in advance is superimposed on the image of the surface, and the print is applied And its It is preferable to perform an appearance inspection except for the vicinity.
In addition, the visual inspection circuit may include a portion of the output data of the imaging device on which the surface of the tablet is printed. And its It is preferable to replace nearby data with predetermined data set in advance.
[0010]
Further, in each of the above configurations, the print inspection circuit may include a portion of the output data of the imaging device on which the printing of the surface of the tablet is performed. And its It is preferable to perform the print inspection based only on the nearby data.
In addition, the printing inspection circuit has been subjected to printing of the tablets obtained by the imaging device The second It is preferable that a predetermined pattern stored in advance is superimposed on the image of the surface, and print inspection is performed on the overlapped portion of the pattern.
It is preferable that the print inspection circuit counts the number of pixels in the output data of the photographing device that overlap the printed portion applied to the surface of the tablet and the overlapped pattern.
[0011]
In each of the above configurations, the appearance inspection circuit and the print inspection circuit each independently binarize output data of the photographing device based on a predetermined threshold value, and the threshold value can be independently set. It is preferable that
In each of the above configurations, it is preferable that the imaging device is a one-dimensional line sensor, and that one imaging device captures an image of a plurality of rows of tablets.
In addition, the visual inspection circuit and the print inspection circuit are provided in the same number as the number of rows of tablets to be photographed for each of the photographing devices, and only the data corresponding to the tablets in each row among the output data of the photographing device. Is preferably input to the visual inspection circuit and the print inspection circuit corresponding to the tablets in each row.
[0012]
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
The tablet printing apparatus of the present invention is provided so as to face at least a transport unit (for example, a transport drum or a horizontal transport conveyor) for transporting tablets in a predetermined arrangement state, and a transport surface of the transport unit. A printing unit for performing predetermined printing, A first inspection unit that is provided upstream of the printing unit in the transport direction of the transport unit and that performs a visual inspection of a first surface on which tablet printing is not performed; Provided downstream of the printing unit in the transport direction of the transport unit, On the opposite side of the first side printing But Given Second Perform surface appearance inspection and print inspection simultaneously in parallel Second Including an inspection unit, Second Inspection unit is tablet printed The second It has a photographing device (such as a CCD camera) for photographing a surface and a visual inspection circuit and a print inspection circuit for performing a visual inspection and a print inspection based on output data of the photographing device. The appearance inspection circuit and the print inspection circuit perform the appearance inspection and the print inspection of the printing surface simultaneously and in parallel immediately after printing on the surface of the tablet based on the output data from the imaging device. In addition, since a photographing device that requires a relatively large space is used in common for tablet appearance inspection and printing inspection, the configuration of the entire tablet printing device is simplified and downsized. Furthermore, since the appearance inspection circuit for performing the appearance inspection and the print inspection circuit for performing the print inspection are provided independently, the threshold values in both circuits are set independently, and the color of the pocket part in the appearance inspection of the tablet is different from the threshold value. Even if the contrast ratio of the tablet color and the contrast ratio of the tablet color and the ink color in the print inspection are significantly different, the optimal tablet appearance inspection and printing can be achieved by appropriately adjusting the threshold values of both circuits. An inspection is performed. In addition, since both circuits can be made compact by integration or the like, even if they are provided independently, the overall size of the tablet printing apparatus hardly increases.
[0014]
In addition, the appearance inspection circuit was printed with tablets obtained by the imaging device. Second A part where a predetermined pattern stored in advance is superimposed on the image of the surface and printed And its Since the appearance inspection is performed except for the vicinity, it is not determined that foreign matter has adhered past the printed portion. More specifically, the portion of the output data of the imaging device where the surface of the tablet is printed And its The nearby data is replaced with predetermined data set in advance.
[0015]
On the other hand, since the printing range of the tablet surface is limited, the print inspection circuit determines the portion of the output data of the imaging device where the printing of the tablet surface is performed. And its The print inspection is performed based only on the neighboring data. In addition, the tablets obtained by the photographing device were printed Second A predetermined pattern stored in advance is superimposed on the image of the surface, and a print inspection is performed on the overlapped portion of the pattern. More specifically, the number of pixels in the output data of the imaging device that overlap the printed portion applied to the surface of the tablet and the overlapping pattern are counted. Therefore, it is possible to perform an AND operation on the data obtained by the photographing apparatus and the data corresponding to the predetermined pattern stored in advance by using a dedicated logic circuit, and perform the processing in real time. . Further, there is no need to temporarily store the obtained data in a memory or the like, read it out to a microcomputer (CPU), and process it, thereby simplifying the circuit configuration.
[0016]
Each of the appearance inspection circuit and the print inspection circuit independently binarizes output data of the photographing device based on a predetermined threshold value, and performs digital signal processing using a microcomputer, a logic circuit, or the like. In addition, since the threshold value can be set independently, the threshold value of both circuits can be adjusted appropriately according to the contrast ratio between the pocket color and the tablet color and the contrast ratio between the tablet color and the ink color. By doing so, the optimal tablet appearance inspection and printing inspection are performed.
[0017]
Using a one-dimensional line sensor as an imaging device, a plurality of rows of tablets are imaged by one imaging device. In this case, the visual inspection circuit and the print inspection circuit are provided in the same number as the number of rows of tablets to be photographed for each photographing apparatus, and only the data corresponding to the tablets in each row among the output data of the photographing apparatus is included in each row. Input to the visual inspection circuit and printing inspection circuit corresponding to the tablet.
[0018]
[0019]
Hereinafter, a preferred embodiment of the tablet printing apparatus of the present invention will be described in detail with reference to the drawings. FIG. 1 shows an arrangement of each unit constituting an embodiment of the tablet printing apparatus of the present invention. The tablet printing apparatus illustrated in FIG. 1 includes a horizontal transport unit 10 that horizontally transports tablets in an aligned state, and an alignment unit 20 that is provided near an upstream end of the horizontal transport unit 10 in the transport direction and aligns tablets. A printing unit 30 provided near the center of the horizontal transport unit 10 for printing predetermined characters and symbols on the surface of the tablet; and a third unit provided to face the third drum 23 of the alignment unit 20. A first inspection unit 40 for inspecting the appearance of the non-printed surface of the tablets arranged on the drum 23, and an appearance inspection of the printed surface of the tablet provided downstream of the printing unit 30 in the transport direction of the horizontal transport unit 10 And a control unit 6 provided with a second inspection unit 50 for performing a print inspection, a drive mechanism for driving each unit, a determination circuit for performing a tablet appearance inspection, a print inspection, and the like. It is composed of, or the like.
[0020]
Next, detailed configurations of the alignment unit 20 and the first inspection unit 40 are shown in FIG. The alignment unit 20 includes first, second, and third drums 21, 22, and 23 that are arranged in a substantially vertical direction, and first, second, and third drums that are provided near outer peripheral portions of the drums 21 to 23. , A tablet hopper 24 provided on the outer peripheral portion of the first drum 21, a brush roller 25 provided on the outer peripheral portion of the first drum 21, and the like. The first drum 21 has a plurality of rows of first pockets 21a in the direction of the rotation axis thereof, and the first pockets 21a hold the tablets in the vertical direction, that is, the circular cross section is substantially vertical. A guide groove 24a is provided at the bottom of the tablet hopper 24 so as to face each row of the first pockets 21a, and the width of each guide groove 24a is larger than the thickness of the tablet in the direction perpendicular to the circular cross section. Are also widened by a predetermined tolerance, and the tablets can be arranged only in the vertical direction as shown in FIG. The brush roller 25 rotates in the direction opposite to the transport direction of the first drum 21 (the direction of rotation is the same as the direction of the first drum 21), and removes excess tablets that did not fit into the first pocket 21a. .
[0021]
The first and third guide plates 26 and 28 are for guiding the tablets so as not to fall from the first and third pockets 21a and 23a provided on the first and third drums 21 and 23, respectively. It is. On the other hand, the second guide plate 27 guides the tablet not to fall from the second pocket 22a provided in the second drum 22, and vertically moves from the first pocket 21a to the second pocket 22a. This is for changing the posture of the transferred tablet in the lateral direction, that is, so that the circular cross section is substantially parallel to the rotation axis. A substantially V-shaped groove (not shown) is formed in the second guide plate 27 so as to correspond to each row of the second pockets 22a, and is held in the vertical direction and largely protrudes from the second pockets 22a. When the tablet abuts on the end face of the substantially V-shaped groove, the tablet is turned over and the posture is changed in the lateral direction.
[0022]
The third drum 23 conveys the tablet, the posture of which has been changed in the horizontal direction by the second drum 22 and the second guide plate 27, as it is in the horizontal direction. A visual inspection is performed. At this stage, since no printing is performed on the tablets, only the appearance inspection is performed. The first inspection unit 40 includes a photographing device (camera) 41, a lighting device 42, and the like. The image capturing device 41 may be either a one-dimensional line sensor camera or a two-dimensional color camera, and a commercially available product can be used. Note that the alignment unit 20 is provided near the upstream end in the transport direction of the horizontal transport unit 10 as described above, and is arranged horizontally so as to face each row of the third pockets 23a of the third drum 23. The slats 11 of the transport unit 10 are arranged.
[0023]
Next, the detailed configurations of the horizontal transport unit 10 and the second inspection unit 50 near the transfer roller 31 of the printing unit 30 are shown in FIG. 3 (the illumination device is omitted). In the case of the present embodiment, at least the second inspection unit 50 has a plurality of photographing devices (cameras) 51, and one photographing device inspects the appearance of tablets in a plurality of rows (for example, four rows in FIG. 3) or It is set to perform print inspection. The second inspection unit 50 is provided on the downstream side in the transport direction of the horizontal transport unit 10 with respect to the printing unit 30 as described above, and performs the appearance inspection and the print inspection of the printing surface of the tablet. The imaging device 51 of the second inspection unit 50 is a one-dimensional line sensor camera, and uses, for example, a CCD of 2048 pixels as a sensor. If the angle of view (or focal length) of the photographing lens is appropriately selected and a width of 0.05 mm is assigned to one pixel, one photographing device 51 can photograph a range of about 100 mm in width. Generally, the diameter of a commercially available tablet is in the range of 5 to 11 mm, so that it is sufficiently possible to inspect a plurality of rows of tablets simultaneously with one imaging device 51. In the transport direction, the photographing is performed 150 to 250 times per tablet. The printing unit 30 includes a design roller 32, a cleaning roller 33, an ink pan 34, and the like in addition to the transfer roller 31 as shown in FIG. 1, but the configuration and function of the printing unit 30 are conventionally used. Therefore, the description is omitted.
[0024]
Next, processing of an output signal of each imaging device 51 of the second inspection unit will be described with reference to FIG. In FIG. 4, reference numerals 201 to 204 denote tablets in the first to fourth rows, respectively, which are transported on the horizontal transport unit 10. Further, a scanning line A indicates a range where an image is formed on the CCD 200 which is a one-dimensional line sensor of the photographing device 51, and corresponds to a one-dot chain line A orthogonal to the tablet conveying direction in FIG. Output data of the first to 512th addresses of the CCD 200 correspond to the tablets 201 in the first row and are input to the determination circuit 211 in the first row. The output data at addresses 513 to 1024 correspond to the tablets 202 in the second column, and are input to the determination circuit 212 in the second column. The output data at addresses 1024 to 1536 correspond to the tablets 203 in the third column, and are input to the determination circuit 213 in the third column. The output data at addresses 1537 to 2048 corresponds to the tablets 204 in the fourth column, and is input to the determination circuit 214 in the fourth column. The output of the CCD 200 input to each of the determination circuits 211 to 214 is simultaneously output to the appearance inspection circuits 221 to 224 and the print inspection circuits 231 to 234, respectively. Note that the distribution of the output signal for one scanning line is performed for each scanning line until the entire range of each of the tablets 201 to 204 is covered. As a result, if the data input to each of the appearance inspection circuits 221 to 224 and each of the print inspection circuits 231 to 234 are reproduced, an image as shown in FIG. 6 is obtained.
[0025]
Next, the appearance inspection and the print inspection performed in the appearance inspection circuits 221 to 224 and the print inspection circuits 231 to 234 will be described with reference to FIGS. As shown in each figure, it is assumed that a symbol such as “A123” is printed on the surface of the tablet. In the tablet printing apparatus according to the present invention, the sensitivity of the photographing device 51 is fixed in order to share the photographing device 51 with respect to the appearance inspection and the print inspection of the tablet printing surface, and the threshold value of the appearance inspection circuits 221 to 224 and the print inspection By adjusting the threshold values of the circuits 231 to 234, the visual inspection of the tablet (determination of cracking, chipping, presence / absence of foreign matter, etc.) of the tablet and the printing inspection (determination of print quality) are separately performed.
[0026]
In the visual inspection of the tablet, for example, as shown in FIG. 5A, a pattern previously stored in a ROM or the like is superimposed on the obtained image, a print area indicated by oblique lines is covered, and A visual inspection is performed on the remaining area that is not present. As an example, the appearance inspection is performed for the entire area by replacing the data of the area shaded with hatching in advance and replacing the data. As described above, the contrast ratio between the color of the pocket portion and the color of the tablet in the visual inspection of the tablet and the contrast ratio between the color of the tablet and the color of the ink in the determination of the quality of printing may greatly differ. In this case, if the printed area is determined using a threshold value for visual inspection, there is a possibility that the printed symbol or the like is erroneously determined to be a foreign substance. On the other hand, if cracks, chips, foreign matter, or the like occur in the print area indicated by oblique lines, ink does not adhere well to that part, and it is determined to be defective in a print inspection described later. Therefore, there is no particular problem even if the printed area is not inspected in the appearance inspection of the tablet.
[0027]
In the case of a visual inspection of a tablet, for example, the uppermost scanning line is determined for each pixel in the X direction in order from the upper left pixel in FIG. The direction is determined. This is repeated to make a determination up to the lower right pixel. The determination is performed according to the following procedure. First, the data of each pixel is binarized depending on whether the data is above or below a predetermined threshold. For example, the pocket portion subjected to black alumite processing has a low output level of the CCD 200, and thus has a value of "0". The tablet portion has a higher output level than the pocket portion and has a value of "1". Next, the appearance inspection circuits 221 to 224 search for a scanning line in which “1” appears a plurality of times in succession, and determine that the scanning line is an edge in the transport direction of the tablet. As shown in FIG. 6, when the appearance of the tablet is normal, the pixel in which "1" first appears in each column moves to the left in order, and moves to the right after passing through the portion of the maximum width. Also, the number of consecutive "1" s gradually increases, and gradually decreases after passing through the portion having the maximum width. If the tablet is cracked or chipped, the position of the pixel where "1" appears at the beginning of each row becomes irregular, or "0" is mixed in the sequence of "1". Also, in the case of the adhesion of foreign matter, “0” is similarly mixed during the continuation of “1”. Therefore, by judging whether the data of each pixel is “0” or “1”, the appearance of the tablet can be inspected. In this case, the data of each pixel is forcibly replaced with "1" in the print area shaded by the diagonal lines.
[0028]
On the other hand, in the printing inspection of tablets, since the printing area is limited, as shown in FIG. 5B, the printing area is not subjected to the printing inspection, and only the printing area not covered by the oblique line is not subjected to the printing inspection. Perform print inspection. As an example, a signal is input to the print inspection circuits 231 to 234 at the same time as the appearance inspection circuits 221 to 224, but the input signal is discarded without performing any processing until the first set time has elapsed. When the second set time has elapsed, the print inspection is terminated and the input signal is discarded. Similarly, in the case of the tablet printing inspection, the uppermost scanning line is determined for each pixel in the X direction in order from the upper left pixel only for the range shown in FIG. 7, and when it reaches the right end, it is lowered by one in the Y direction. Are similarly determined in the X direction. This is repeated to make a determination up to the lower right pixel. The print inspection circuits 231 to 234 search for the head of each character “A”, “1”, “2”, and “3” of “A123” and determine the quality of the printed character.
[0029]
In the case of the tablet printing inspection, "0" pixels and "1" pixels appear irregularly in accordance with a pattern designed in advance, so that the quality of printing is determined using a method called template matching. That is, when the head of each printed character is detected, the previously stored patterns of "A", "1", "2", and "3" are superimposed on the data read by the CCD 200, and for each character, both are read. Count the number of overlapping pixels. In FIG. 8, (a) shows a state where the character “A” is normally printed, (b) shows a state where the printed character is partially missing, and (c) shows a state where the printed character is partially missing. Indicates a short case. In the case shown in (a), since the printed letter "A" and the pre-stored template letter "A" indicated by the dashed line completely match, it corresponds to the template letter "A". The number of pixels to be counted is counted. On the other hand, in the case of (b) and (c), the character "A" is partially missing or short, so that a portion that does not overlap with the template character "A" indicated by a dashed line is generated, and the corresponding portion is counted. Pixel count is small. Therefore, in the cases (b) and (c), it is determined that the printing is defective.
[0030]
For example, consider the case where the ground color of the tablet is bright and the color of the ink used for printing is dark. The data of the pixel corresponding to the printed symbol or the like is “0”, and the data of the pixel of the unprinted tablet background portion is “1”. As described above, when the head of a printed character or the like is detected, the position of a pixel that should become “0” or “0” and “1” from a pattern of a character or the like to be printed in advance is determined based on the pattern. You can see the sequence of the data. Here, using a dedicated logic circuit, an AND (logical sum) of the arrangement of the data read by the CCD 200 and the data of "0" and "1", which is known in advance, is obtained, and the two do not match, ie, "0". The number of “1” among the pixels to be “1” is counted, and when the number exceeds a predetermined allowable error, it is determined that the printing is defective. Alternatively, the data read by the CCD 200 is temporarily stored in a memory corresponding to each data, the data of the pixel which should be "0" is read out, the number of "1" included therein is counted, and a predetermined tolerance is set. If the error is exceeded, it is determined that printing is defective. In the judgment of the quality of the actual printing, the template matching method is effective because a slightly thick and thin width of a symbol or the like is not so conspicuous, but rather a chipping or the like is more conspicuous. In particular, when a dedicated logic circuit is used, it is not necessary to temporarily store the data read by the CCD 200 in the memory, and it is possible to judge the quality of printing in real time, and it is not necessary to use a microcomputer or a memory. The circuit configuration is simplified.
[0031]
Tablets determined to be defective in one of the tablet appearance inspection and the printing inspection are excluded from the horizontal transport unit 10 or the subsequent transport step by jetting compressed air or the like (not shown for obvious reasons). As a result, in the tablet printing process, the appearance inspection and the printing inspection of both sides of the tablet can be performed at the same time, and a defective product is not included in the tablet conveyed from the tablet printing apparatus of the present invention to the next step.
[0032]
[0033]
Further, in the above embodiment, the horizontal transport unit 10 such as a slat conveyor is used as a means for transporting tablets. However, similar effects can be obtained by using a transport drum or the like as in the conventional example shown in FIG. Needless to say. In this case, the same effect as that of the present invention can be obtained simply by replacing the second inspection unit 105 in the conventional tablet printing apparatus shown in FIG. 9 with the second inspection unit 50 of the present invention. It becomes unnecessary. Therefore, the tablet printing apparatus of the present invention can be obtained by simply remodeling the conventional tablet printing apparatus.
[0034]
【The invention's effect】
As described above, the tablet printing apparatus of the present invention is provided so as to face at least the conveying means for conveying the tablets in a predetermined arrangement state and the conveying surface of the conveying means, and performs predetermined printing on the surface of the tablet. Printing means; A first inspection unit that is provided upstream of the printing unit in the transport direction of the transport unit and that performs an appearance inspection of a first surface on which tablets are not printed; Provided downstream of the printing means in the carrying direction of the carrying means, On the opposite side of the first side printing But Given Second Perform surface appearance inspection and print inspection simultaneously in parallel Second Including inspection means, Second Inspection means printed tablets Second Since it has a photographing device that photographs the surface and a visual inspection circuit and a print inspection circuit that respectively perform visual inspection and print inspection based on output data of the photographing device, visual inspection of the printed surface immediately after printing is performed on the tablet surface And print inspection can be performed simultaneously in parallel. In addition, since a photographing device that requires a relatively large space is used in common for the tablet appearance inspection and printing inspection, the configuration of the entire tablet printing device can be simplified and downsized. Furthermore, since the appearance inspection circuit for performing the appearance inspection and the printing inspection circuit for performing the printing inspection are provided independently, the threshold values of both circuits can be set independently, and the pocket portion in the appearance inspection of the tablet can be set. Even when the contrast ratio between the color and the color of the tablet and the contrast ratio between the color of the tablet and the color of the ink in the determination of print quality are greatly different, the threshold of both circuits is appropriately adjusted to obtain the optimum tablet. Appearance inspection and print inspection can be performed. In addition, since both circuits can be made relatively compact by integration or the like, even if they are provided independently, there is almost no increase in the size of the tablet printing apparatus as a whole.
[0035]
In addition, the appearance inspection circuit was printed with tablets obtained by the imaging device. Second A part where a predetermined pattern stored in advance is superimposed on the image of the surface and printed And its Since the appearance inspection is performed except for the vicinity, it is not determined that foreign matter has adhered past the printed portion, and erroneous determination can be prevented. In addition, the appearance inspection device is a portion of the output data of the photographing device where the surface of the tablet is printed. And its Since the nearby data is replaced with predetermined data set in advance, data processing can be performed by electrical means instead of optical means. As a result, digital signal processing means such as a microcomputer or a logic circuit can be used, and the configuration of the appearance inspection circuit can be simplified.
[0036]
In addition, since the printing range of the tablet surface is limited, a portion of the output data of the photographing device where the printing of the tablet surface is performed is performed by the print inspection circuit. And its By performing the print inspection based only on the neighboring data, it is possible to increase the processing speed without making a determination on unnecessary data. In addition, the tablets obtained by the photographing device were printed Second A predetermined pattern stored in advance is superimposed on the image of the surface, and a print inspection is performed on the overlapped portion of the pattern, so that the data input from the imaging device and the predetermined pattern stored in advance are corresponded. The data can be compared with the data to be printed, and the quality of printing can be determined very easily. Furthermore, by counting the number of overlapping pixels of the printed portion applied to the surface of the tablet and the overlapped pattern in the output data of the photographing device, the data input from the photographing device using a logic circuit can be used in advance. An AND (logical sum) of the data corresponding to the stored predetermined pattern can be obtained, and the print inspection can be performed in real time. Further, there is no need to use a microcomputer, a memory, or the like, and the circuit configuration can be simplified.
[0037]
The visual inspection circuit and the print inspection circuit each independently binarize the output data of the photographing device based on a predetermined threshold value, and since the threshold value can be independently set, a microcomputer or the like is used. Optimized by performing digital signal processing and adjusting the thresholds of both circuits appropriately according to the contrast ratio between the pocket color and the tablet color and the contrast ratio between the tablet color and the ink color Inspection of the appearance and printing inspection of a tablet can be performed.
[0038]
Furthermore, by using a one-dimensional line sensor as an imaging device, it is possible to image a plurality of rows of tablets with one imaging device. In this case, the visual inspection circuit and the print inspection circuit are provided in the same number as the number of rows of tablets to be photographed for each photographing apparatus, and only the data corresponding to the tablets in each row among the output data of the photographing apparatus is included in each row. By inputting to the visual inspection circuit and the print inspection circuit corresponding to the tablet, it is possible to simultaneously perform the visual inspection and the print inspection of a plurality of rows of tablets with one photographing device, thereby dramatically increasing the number of inspections per unit time. This makes it possible to perform a total inspection of tablets without lowering the inspection processing speed and without increasing the size of the apparatus.
[0039]
[Brief description of the drawings]
FIG. 1 is a perspective view showing an arrangement of each constituent unit in an embodiment of a tablet printing apparatus of the present invention.
FIG. 2 is a sectional view showing a detailed configuration of an alignment unit 20 and a first inspection unit 40 shown in FIG.
FIG. 3 is a perspective view showing a detailed configuration of a horizontal transport unit 10 and a second inspection unit 50 near a transfer roller 31 of the printing unit 30 shown in FIG.
FIG. 4 is a schematic diagram showing processing of output data in a second inspection unit 50;
FIG. 5 (a) is a tablet Of the printed surface Appearance inspection Inspection area The figure which shows the area | region, (b) of a tablet Of the printed surface In printing inspection Inspection area Diagram showing area
FIG. 6 is a diagram showing a state in which output data of a photographing device 51 (CCD 200) is reproduced in a tablet appearance inspection.
FIG. 7 is a diagram showing a state in which output data of the photographing device 51 (CCD 200) is reproduced in the tablet print inspection.
8A is a diagram illustrating a state where a printed character is normally printed, FIG. 8B is a diagram illustrating a state where a printed character or the like is partially missing, and FIG. 8C is a diagram illustrating a case where a printed character is short. Illustration
FIG. 9 is a side view showing a configuration of a conventional tablet printing apparatus.
[Explanation of symbols]
10: Horizontal transport unit
11: Slat
20: Alignment unit
21: First drum
21a: first pocket
22: Second drum
22a: second pocket
23: Third drum
23a: Third pocket
24: Tablet hopper
24a: Guide groove
25: Brush roller
26: First guide plate
27: Second guide plate
28: Third guide plate
30: Printing unit
31: Transfer roller
32: Design roller
33: Cleaning roller
34: Ink pan
40: First inspection unit
41: Photographing device
42: Linear lighting device
50: Second inspection unit
51: Photographing device
60: Control unit
200: CCD
201 to 204: tablets
211 to 214: judgment circuit
221-224: Visual inspection circuit
231-234: Print inspection circuit

Claims (9)

A transport unit that transports at least the tablets in a predetermined arrangement state, a printing unit that is provided to face a transport surface of the transport unit, and performs a predetermined print on the surface of the tablet, and the transport unit in the transport direction of the transport unit. A first inspection unit that is provided upstream of the printing unit and performs an appearance inspection of a first surface on which the tablet is not printed; and a first inspection unit that is provided downstream of the printing unit in a transport direction of the transport unit. And a second inspection unit for simultaneously performing a visual inspection and a print inspection of a second surface of the tablet on a side opposite to the first surface on which printing is performed, wherein the second inspection unit performs printing of the tablet. tablet printing apparatus having a visual inspection circuit and the print test circuit for performing each appearance inspection and print inspection based on the output data of the photographed device and the imaging device captures the second surface has been subjected. The appearance inspection circuit, a predetermined pattern stored in advance is superimposed on the image of the second surface on which the tablets are printed by the imaging device, and the printed portion and its 2. The tablet printing apparatus according to claim 1, wherein an appearance inspection is performed except for the vicinity. 3. The tablet printing apparatus according to claim 2, wherein the appearance inspection circuit replaces, in the output data of the photographing apparatus, a portion where the surface of the tablet is printed and data in the vicinity thereof with predetermined data set in advance. . The tablet according to any one of claims 1 to 3, wherein the print inspection circuit performs a print inspection based only on a portion of the output data of the imaging device on which the surface of the tablet has been printed and data in the vicinity thereof. Printing device. The print inspection circuit superimposes a predetermined pattern stored in advance on the image of the second surface on which the printing of the tablet obtained by the photographing device has been performed, and regards the overlapped portion of the pattern. The tablet printing apparatus according to claim 4, which performs a printing inspection. 6. The tablet printing apparatus according to claim 5, wherein the print inspection circuit counts the number of pixels in the output data of the photographing apparatus that overlap the printed portion applied to the surface of the tablet and the overlapped pattern. 7. The visual inspection circuit and the print inspection circuit independently binarize output data of the photographing device based on a predetermined threshold value, and the threshold value can be independently set. The tablet printing device according to any one of the above. The tablet printing apparatus according to any one of claims 1 to 7, wherein the photographing device is a one-dimensional line sensor, and one photographing device photographs a plurality of rows of tablets. The visual inspection circuit and the print inspection circuit are provided in the same number as the number of rows of tablets to be photographed for each of the photographing devices, and among the output data of the photographing device, only data corresponding to tablets in each row is the data. 9. The tablet printing apparatus according to claim 8, wherein the tablet printing apparatus is input to a visual inspection circuit and a print inspection circuit corresponding to tablets in each row.

Images