JP6466302B2 - Tablet printing apparatus and tablet printing method - Google Patents

Description

  Embodiments described herein relate generally to a tablet printing apparatus and a tablet printing method.

  Usually, a tablet printing apparatus is an apparatus that prints identification information such as characters (for example, alphabets, katakana and numbers) and marks (for example, symbols and figures) on the surface of a tablet in order to identify the tablets. As this tablet printing apparatus, an ink jet type tablet printing apparatus that performs printing in a non-contact manner on a tablet has been developed from the viewpoint of easy identification information change and high print quality. An ink jet type tablet printing apparatus discharges ink (for example, edible ink) toward a tablet while transporting the tablet by a transport belt or the like, and prints identification information on the surface of the tablet.

  Various tablets exist as tablets to be printed, and some tablets have front and back surfaces. For example, in a tablet in which a secant for splitting a tablet is formed on one side, usually the side with the secant is the front and the side without the secant is the back. The identification information is printed on both sides (front and back) or one side (front or back) of the tablet.

  The tablets may be supplied on the conveyor belt without being aligned. This is because the process of aligning the front and back of the tablet is unnecessary, and the decrease in productivity and the increase in cost are suppressed. In this case, in order to perform printing according to the front and back of the tablet, it is necessary to determine whether or not the upper surface of the tablet on the transport belt is the front, that is, whether or not there is a secant on the upper surface of the tablet on the transport belt. . Therefore, the tablet printing apparatus photographs the upper surface of the tablet on the conveyance belt using a camera, and processes the image to determine the presence or absence of a secant line.

Japanese Patent Laid-Open No. 7-81050

  However, when the camera is used as described above, it is necessary to photograph the upper surface of the tablet on the conveyor belt and process the image to determine the front and back of the tablet. At this time, image processing for determining the presence / absence of a secant from the image taken by the camera is essential. Furthermore, other image processing related to the secant line is required, and a plurality of image processing is executed. Since these image processes require a long processing time, the printing efficiency for printing on tablets or the inspection efficiency for inspecting the print quality of tablets decreases.

  The problem to be solved by the present invention is to provide a tablet printing apparatus and a tablet printing method capable of improving printing efficiency or inspection efficiency.

The tablet printing apparatus according to the embodiment includes a transport unit that transports a tablet having a secant on one surface, an image capturing unit that captures an image of the tablet transported by the transport unit, and an upstream side of the image capturing unit. Obtained by the detection unit that outputs a signal corresponding to the shape of the surface of the tablet, a determination unit that determines whether there is a secant on the surface of the tablet based on the output of the detection unit, and the imaging unit a processing unit for processing the image, and a print head for printing on the tablets being conveyed by the conveying unit, the processing unit, when it is determined that the dividing line is present on the surface of the tablet by the determination unit, imaging perform a plurality of image processing on the image obtained by parts, if the dividing line on the surface of the tablet is determined not by the determination unit, skip image processing according to the dividing line of the tablet from the plurality of image processing Perform the rest of the image processing.

Tablet printing method according to the embodiment includes the steps of conveying the tablet having a secant on one surface, a step of taking the tablets fed transportable, before imaging the tablets are picked up by step of taking, tablets A step of determining whether or not there is a secant on the surface, a step of processing an image obtained by imaging, and a step of printing on a transported tablet. when it is determined on the surface of the dividing line is present, perform a plurality of image processing on the image obtained by the imaging, if it is determined that there is no secant to the surface of the tablet, from a plurality of image processing The remaining image processing is performed by omitting the image processing relating to the secant of the tablet.

  According to the embodiment of the present invention, printing efficiency or inspection efficiency can be improved.

It is a figure which shows schematic structure of the tablet printing apparatus which concerns on 1st Embodiment. It is a top view which shows a part of 1st printing part with which the tablet printing apparatus which concerns on 1st Embodiment is provided. It is a figure for demonstrating the front and back determination (presence / absence determination of a secant) of the tablet which concerns on 1st Embodiment. It is a 1st flowchart which shows the flow of the printing process of the tablet which concerns on 1st Embodiment. It is a 2nd flowchart which shows the flow of the test | inspection process of the tablet which concerns on 1st Embodiment. It is a figure which shows schematic structure of the tablet printing apparatus which concerns on 2nd Embodiment. It is a flowchart which shows the flow of the printing process of the tablet which concerns on 2nd Embodiment.

(First embodiment)
A first embodiment will be described with reference to FIGS. 1 to 5.

(Basic configuration)
As shown in FIG. 1, the tablet printing apparatus 1 according to the first embodiment includes a tablet supply unit 10, a first printing unit 20, a second printing unit 30, a tablet storage unit 40, and a control unit. 50. The first printing unit 20 and the second printing unit 30 have basically the same structure.

  The tablet supply unit 10 includes a hopper 11, an alignment feeder 12, and a delivery feeder 13. The tablet supply unit 10 is configured to be able to supply tablets T to be printed to the first printing unit 20, and is provided on one end side of the first printing unit 20. The hopper 11 accommodates a large number of tablets T and sequentially supplies the tablets T to the alignment feeder 12. The alignment feeder 12 aligns the supplied tablets T in a line and conveys them toward the delivery feeder 13. The delivery feeder 13 sequentially sucks the tablets T on the alignment feeder 12 and conveys them to the first printing unit 20 in a row and supplies them to the first printing unit 20. The tablet supply unit 10 is electrically connected to the control unit 50, and the driving thereof is controlled by the control unit 50. In addition, as the alignment feeder 12 and the delivery feeder 13, for example, a belt conveyance mechanism or the like can be used.

  Here, when supplying the tablet T, the hopper 11 ignores the front and back of the tablet T and supplies the tablet T to the alignment feeder 12. For this reason, the front tablet T and the back tablet T are mixed on the alignment feeder 12. The front of the tablet T is a surface having a secant (for example, a groove), and the back of the tablet T is a surface having no secant.

  The first printing unit 20 includes a transport unit 21, a detection unit 22, an imaging unit for printing (first imaging unit) 23, a print head 24, and an imaging unit for inspection (second imaging unit). 25, a drying unit 26, and a recovery unit 27.

  The transport unit 21 includes a transport belt 21a, a first pulley 21b, a second pulley 21c, and a motor 21d. The conveyor belt 21a is formed in an endless shape and is stretched over the first pulley 21b and the second pulley 21c. The first pulley 21b is connected to a motor 21d serving as a drive source and functions as a drive pulley. The second pulley 21c functions as a driven pulley. The motor 21 d is electrically connected to the control unit 50, and its driving is controlled by the control unit 50.

  Such a transport unit 21 rotates the transport belt 21a together with the second pulley 21c by the rotation of the first pulley 21b by the motor 21d, and the tablet T on the transport belt 21a is transported in the direction indicated by the arrow A1 in FIG. Transport in direction A1). As shown in FIG. 2, a plurality of suction holes H are formed in the transport belt 21a in a line along the transport direction A1. Each suction hole H is connected to an intake device (not shown) via a suction chamber, and obtains suction force by driving the intake device (for example, a suction pump). The tablet T supplied onto the suction hole H is held on the transport belt 21 a by suction through the suction hole H.

  The detection unit 22 is positioned on the downstream side in the transport direction A1 from the position where the tablet T is supplied by the tablet supply unit 10, and is provided above the transport belt 21a. As the detection unit 22, for example, various laser sensors (laser displacement meters) such as a reflection type laser sensor can be used. Various shapes such as spots and lines can be used as the beam shape of the laser light. And the detection part 22 provided above the conveyance belt 21a and facing the conveyance belt 21a can irradiate a laser beam on the upper surface (for example, substantially the center of the upper surface) of the tablet T conveyed by the conveyance belt 21a. Is arranged.

  Such a detection part 22 irradiates a laser beam toward the tablet T on the transport belt 21a, receives the laser light (reflected light) reflected by the tablet T, and sets the reflection intensity of the laser light to the control part 50. Send. The reflection intensity of the laser light is information indicating the separation distance between the surface of the conveyor belt 21 a or the upper surface of the tablet T on the conveyor belt 21 a and the detection unit 22. The detection unit 22 also detects the position of the tablet T on the transport belt 21a (position in the transport direction A1) by projecting and receiving laser light, and also functions as a trigger sensor for each device located downstream. The detection unit 22 is electrically connected to the control unit 50, and transmits to the control unit 50 information on the position of the tablet T on the conveyor belt 21a (position information) and information on the reflection intensity of the laser beam (reflection intensity information). To do.

  The first imaging unit 23 is positioned downstream of the detection unit 22 in the transport direction A1 and is provided above the transport belt 21a. The first imaging unit 23 performs imaging at a timing based on the position information of the tablet T described above, acquires an image including the upper surface of the tablet T (image for printing), and transmits the acquired image to the control unit 50. To do. As the first imaging unit 23, for example, various imaging units having an imaging element such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor) can be used. The first imaging unit 23 is electrically connected to the control unit 50, and its driving is controlled by the control unit 50. Note that illumination for imaging is also provided as necessary.

  The print head 24 is an inkjet print head that individually ejects ink from a plurality of nozzles N (see FIG. 2). The print head 24 is positioned downstream of the imaging unit 23 in the transport direction A1, and the transport belt 21a is arranged such that the nozzle alignment direction in which the nozzles N are aligned intersects the transport direction A1 in the horizontal plane (for example, orthogonal). It is provided above. As the print head 24, for example, various ink jet print heads having drive elements such as piezoelectric elements, heat generating elements, or magnetostrictive elements can be used. The print head 24 is electrically connected to the control unit 50, and its driving is controlled by the control unit 50.

  The second imaging unit 25 is positioned on the downstream side in the transport direction A1 from the print head 24, and is provided above the transport belt 21a. The second imaging unit 25 performs imaging at a timing based on the position information of the tablet T described above, acquires an image (inspection image) including the upper surface of the printed tablet T, and uses the acquired image as a control unit. 50. As the second imaging unit 25, for example, various imaging units having an imaging element such as a CCD or a CMOS can be used. The second imaging unit 25 is electrically connected to the control unit 50, and its driving is controlled by the control unit 50. Note that illumination for imaging is also provided as necessary.

  The drying unit 26 is positioned downstream of the imaging unit 25 in the transport direction A1, and is provided below the transport belt 21a, that is, below the transport unit 21. The drying unit 26 dries the ink applied to each tablet T on the transport belt 21a. As the drying unit 26, it is possible to use various types of drying units such as a heater that dries an object to be dried by radiant heat or a blower that dries an object to be dried by warm air or hot air. The drying unit 26 is electrically connected to the control unit 50, and its driving is controlled by the control unit 50.

  The collection unit 27 is positioned downstream of the drying unit 26 in the conveyance direction A1, and is provided below the conveyance belt 21a, that is, below the conveyance unit 21. The ejection nozzle 27a for the collection unit 27 is provided in the conveyance unit 21 so as to face the collection unit 27 with the conveyance belt 21a interposed therebetween. The spray nozzle 27a sprays gas (for example, air) onto the tablet T (defective product tablet T) on the transport belt 21a, and drops the tablet T from the transport belt 21a. For this reason, the collection | recovery part 27 is formed so that it can receive and collect | recover the tablet T which falls. The injection nozzle 27 a is electrically connected to the control unit 50, and its driving is controlled by the control unit 50.

  The tablet T (good tablet T) that has not been dropped by the injection nozzle 27a is transported as the transport belt 21a moves, and is located near the end of the transport belt 21a on the first pulley 21c side. . At this position, the suction action does not act on the tablet T, and the tablet T is released from the state held by the transport belt 21 a and is transferred from the first printing unit 20 to the second printing unit 30.

  Similar to the first printing unit 20 described above, the second printing unit 30 includes a transport unit 31, a detection unit 32, a printing imaging unit (first imaging unit) 33, a print head 34, and an inspection. An imaging unit (second imaging unit) 35, a drying unit 36, and a collection unit 37. The transport unit 31 includes a transport belt 31a, a first pulley 31b, a second pulley 31c, and a motor 31d. An injection nozzle 37a for the collection unit 37 is also provided. Since the description of each part is the same as that of the first printing part 20 described above, a description thereof will be omitted. The transport direction of the second printing unit 30 is the direction of the arrow A2 in FIG. 1 (transport direction A2).

  The tablet storage unit 40 is positioned downstream of the collection unit 37 of the second printing unit 30 in the transport direction A2, and is provided at the end of the transport unit 31, that is, the end of the transport belt 31a on the second pulley 31c side. It has been. The tablet container 40 is configured to be able to sequentially receive and collect the tablets T that are released from being held by the transport belt 31a and fall. In addition, the conveyance part 31 cancel | releases holding | maintenance of the tablet T when each tablet T on the conveyance belt 31a reaches | attains a desired position, for example, the edge part of the conveyance direction A1 in the conveyance belt 31a downstream.

  The control unit 50 includes a determination unit 51, an image processing unit 52, a print processing unit 53, an inspection processing unit 54, and a storage unit 55. The determination unit 51 performs various determinations. The image processing unit 52 processes an image. The print processing unit 53 performs processing related to printing. The inspection processing unit 54 performs processing related to inspection. The storage unit 55 stores various information such as processing information and various programs. Such a control unit 50 includes the position information of the tablet T and the reflection intensity of the laser beam transmitted from the individual detection units 22 and 32 of the first printing unit 20 and the second printing unit 30, and the first printing unit. 20 and images transmitted from the individual imaging units 23, 25, 33, and 35 of the second printing unit 30 are received.

(Determination of front and back of tablet T)
The determination unit 51 determines the front and back of the tablet T based on the reflection intensity information of the laser light transmitted from the detection units 22 and 32, that is, whether or not there is a secant on the upper surface of the tablet T (whether or not there is a secant on the upper surface of the tablet T). ). That is, if there is a secant on the upper surface of the tablet T, it is determined to be a front side, and if there is no secant, it is determined to be the back side. The result of this determination is front / back information, which is stored in the storage unit 55. The front / back information may simply be secant presence / absence information. Since the detection units 22 and 32 are basically the same, the detection unit 22 will be described as a representative.

  As shown in FIG. 3, the laser spot S <b> 1 of the detection unit 22 passes through almost the center of the upper surface of the relatively moving tablet T. Each tablet T is conveyed in a row with its center positioned on a predetermined line, but some tablets T have their centers shifted from the predetermined line. However, since this shift amount is small, the tablets T are transported in almost one row.

  The output (laser beam reflection intensity) B1 of the detection unit 22 changes according to the separation distance between the detection unit 22 and the surface of the transport belt 21a or the upper surface of the tablet T on the transport belt 21a. For example, the output B1 becomes the reflection intensity b1 when the tablet T is not present on the transport belt 21a, that is, when the laser spot S1 hits the surface of the transport belt 21a. Further, the output B1 is reflected intensity b2 when the laser spot S1 hits the upper surface in the dividing line (for example, groove) of the tablet T on the conveying belt 21a, and reflected intensity b3 when it hits the upper surface other than the dividing line of the tablet T on the conveying belt 21a. (B1 <b2 <b3). At this time, the output B1 changes according to the change in the height of the tablet T on the transport belt 21a. In other words, the detection unit 22 detects the height of the tablet T being transported on the transport belt 21a. That is, when the tablet T transported on the transport belt 21a passes directly below the detection unit 22, when the tablet T reaches the laser spot S1, the reflection intensity b2 or the reflection intensity b3 is output (from the reflection intensity b1). When the tablet T passes the laser spot S1, the output intensity B1 is repeatedly returned (the output B1 falls). Therefore, the tablet T is from the rise to the fall of the output B1.

  The determination unit 51 determines whether or not there is a secant on the upper surface of the tablet T on the transport belt 21a based on the output B1 of the detection unit 22 described above, and whether or not the tablet T has reached a predetermined position. Determine. For example, the determination unit 51 determines that there is a secant on the upper surface of the tablet T on the transport belt 21a when the reflection intensity b2 occurs between the rising and falling of the output B1, and in other cases, the transport belt It determines with there being no secant on the upper surface of the tablet T on 21a. As another determination example, the determination unit 51 sets a predetermined value between the reflection intensity b1 and the reflection intensity b2 as a first threshold (b1 <first threshold <b2), and the reflection intensity b2 and the reflection intensity b3. As a second threshold value (b2 <second threshold value <b3), the output B1 is larger than the first threshold value and smaller than the second threshold value between the rising edge and the falling edge. In this case, it may be determined that there is a secant on the upper surface of the tablet T on the transport belt 21a, and in other cases, it may be determined that there is no secant on the upper surface of the tablet T on the transport belt 21a. Further, the determination unit 51 determines that the tablet T has reached a predetermined position (position detection) when the output B1 becomes larger than the reflection intensity b1 (rising edge of the reflection intensity signal).

(Printing and inspection processing)
Next, printing and inspection processing (printing and inspection process) performed by the tablet printing apparatus 1 described above will be described with reference to FIGS. 4 and 5. 4 shows the flow of the printing process of the first printing unit 20, and FIG. 5 shows the flow of the inspection process of the first printing unit 20. Note that the flow of printing and inspection processing by the second printing unit 30 is the same as that of the first printing unit 20, and thus description thereof is omitted.

  As shown in FIG. 4, in step S <b> 1, the tablets T start to be sequentially supplied from the hopper 11 to the alignment feeder 12, and are aligned in a line by the alignment feeder 12. The tablets T moving in a row are sequentially supplied to the transport belt 21a by the delivery feeder 13. The transport belt 21a is rotated in the transport direction A1 by the rotation of the first pulley 21b and the second pulley 21c by the motor 21d. For this reason, the tablets T supplied onto the conveyor belt 21a are conveyed in a line on the conveyor belt 21a. The transport belt 31a is also rotated in the transport direction A2 by the rotation of the first pulley 31b and the second pulley 31c by the motor 31d.

  In step S2, the tablet T on the transport belt 21a is detected by the detection unit 22 (sensor 1). Thereby, the position information of the tablet T (position in the transport direction A1) and the reflection intensity information of the laser beam are acquired and input to the control unit 50. Further, the determination unit 51 determines whether or not there is a secant on the upper surface of the tablet T on the transport belt 21a based on the reflection intensity information of the laser light (front / back information). The position information and front / back information of the tablets T are stored in the storage unit 55 and used in post-processing.

  In step S3, the tablet T on the transport belt 21a is imaged by the first imaging unit 23 (camera 1). The upper surface of the tablet T is captured by the first imaging unit 23 at a timing based on the position information of the tablet T described above, and the captured image is transmitted to the control unit 50.

  In step S <b> 4, the center of gravity of the tablet T is determined by the image processing unit 52. In determining the center of gravity of the tablet T, the outer edge portion or the entire portion is extracted from the image captured by the first imaging unit 23 by image processing, and the center of gravity of the tablet T is obtained. Then, an offset amount (position information) between the obtained center of gravity and the center of the reference coordinate is calculated. This offset amount is stored in the storage unit 55 as appropriate.

  In step S5, based on the front / back information stored in the storage unit 55, the print processing unit 53 determines whether or not the tablets T on the transport belt 21a are front. If it is determined that the tablet T is a table (YES), the process proceeds to step S6. On the other hand, when it is determined that the tablet T is the back side (NO), the process proceeds to step S9. Thereby, when the tablet T is the back, the secant detection process of step S6 and the secant angle determination process of step S7 are omitted.

  In step S <b> 6, the secant detection of the tablet T is performed by the image processing unit 52. In the detection of the dividing line of the tablet T, a feature extraction process and a pattern matching process are performed by image processing in order to grasp a pattern corresponding to the dividing line in the vicinity of the center portion (center of gravity) of the reference coordinates.

  In step S <b> 7, the dividing angle determination of the tablet T is performed by the image processing unit 52. In the secant angle determination, the angle between the secant and the reference coordinates is calculated by image processing from the secant portion partial extracted image extracted by the above feature extraction processing. This angle information is stored in the storage unit 55 as appropriate.

  In step S <b> 8, the application position calculation and front print pattern data generation are performed by the print processing unit 53. The application position is calculated based on the offset amount described above, and the front print pattern data is generated based on the angle information of the secant. For example, based on the above-mentioned angle information of the dividing line, the optimum pattern data (for example, pattern data whose identification information is parallel to the dividing line) is selected as the table printing pattern data from the table printing pattern data for each predetermined angle (for example, 1 degree). Is done. The front print pattern data for each predetermined angle is stored in advance in the storage unit 55 and is read from the storage unit 55 and used.

  In step S <b> 9, calculation of the application position and generation of back print pattern data are performed by the print processing unit 53. The application position is calculated based on the above-described offset amount, and desired back print pattern data is generated. For example, desired back print pattern data is stored in the storage unit 55 in advance, and is read from the storage unit 55 and used.

  In the above-described back printing, printing is performed on the back of the tablet T regardless of the angle of the secant, but the present invention is not limited to this. For example, there is a case where printing is not performed on the back side of the tablet T, or identification information is printed on the back side of the tablet T in parallel with the dividing line of the front surface based on the angle information of the front dividing line. (Refer to the second embodiment).

  In step S10, printing is performed by the print head 24 based on the front print pattern data or the back print pattern data. The tablets T on the conveyor belt 21a are printed by the print head 24 based on the application position information and the print pattern data (front print pattern data or back print pattern data) at a timing based on the position information of the tablets T described above. The Ink is appropriately ejected from each nozzle N of the print head 24, and identification information such as characters and marks is printed on the upper surface of the tablet T.

  Next, as shown in FIG. 5, in step S11, the printed tablet T on the conveyor belt 21a is imaged by the second imaging unit 25 (camera 2). The upper surface of the tablet T is captured by the second imaging unit 25 at a timing based on the position information of the tablet T described above, and the captured image is transmitted to the control unit 50.

  In step S12, the center of gravity of the printed tablet T is determined by the image processing unit 52. In determining the center of gravity of the tablet T, the outer edge portion or the entire portion is extracted by image processing from the image captured by the second imaging unit 25, and the center of gravity of the tablet T is obtained. An offset amount (position information) between the obtained center of gravity and the center of the reference coordinate is calculated. This offset amount is stored in the storage unit 55 as appropriate.

  In step S13, based on the front / back information stored in the storage unit 55 described above, the inspection processing unit 54 determines whether or not the printed tablets T on the transport belt 21a are front. If it is determined that the printed tablet T is a table (YES), the process proceeds to step S14. On the other hand, when it is determined that the printed tablet T is the reverse side (NO), the process proceeds to step S17.

  In step S <b> 14, the dividing angle determination of the printed tablet T is performed by the image processing unit 52. In the secant angle determination, the angle between the secant and the reference coordinates is calculated by image processing from the secant portion partial extracted image extracted by the above feature extraction processing. This angle information is stored in the storage unit 55 as appropriate.

  In step S <b> 15, extraction (print extraction) of a printed image (identification information such as characters and marks) of the printed tablet T is performed by the image processing unit 52. In the print extraction, a print image (for example, a print pattern) is extracted from the image captured by the second imaging unit 25 by image processing.

  In step S <b> 16, table pattern matching is performed by the image processing unit 52. In the table pattern matching, the extracted print image (print pattern) and the reference pattern are subjected to gravity center alignment and angle alignment based on the position information obtained in step S12 and the angle information obtained in step S14, and extracted. The printed image and the reference pattern are compared. Thus, when the relative angle relationship between the extracted print image and the reference pattern is unknown, the patterns to be compared are compared while being relatively rotated, and the matching rate is obtained for each predetermined angle (for example, 1 degree). For example, it is not necessary to perform a processing step of determining pass / fail by obtaining a maximum value from matching rate data for an angle of 180 °.

  If the position and angle deviation of the tablet T are negligible before and after the printing process, step 12 and step 14 are not performed, and the information stored in the storage unit 55 in step 4 and step 7 is used. You can also. In this case, the time for performing step 12 and step 14 is shortened.

  In step S <b> 17, the image processing unit 52 extracts (prints and extracts) a back side printed image (identification information such as characters and marks) of the printed tablet T. In the print extraction, a print image (for example, a print pattern) is extracted from the image captured by the second imaging unit 25 by image processing.

  In step S <b> 18, the back pattern matching is performed by the image processing unit 52. In the back pattern matching, the extracted print image (print pattern) and the reference pattern are compared while relatively rotating. Thereby, a matching rate is calculated | required for every predetermined angle (for example, 1 degree). The matching rate for each predetermined angle is stored in the storage unit 55 as appropriate.

  In step S19, the non-defective product determination is performed by the inspection processing unit 54. It is determined whether or not the maximum value of the matching rate is equal to or greater than a predetermined value. When it is determined that the maximum value of the matching rate is equal to or greater than the predetermined value (YES), the tablet T is determined to be a non-defective product, and the non-defective tablet T is conveyed as it is and supplied to the second printing unit 30. On the other hand, if it is determined that the maximum value of the matching rate is not equal to or greater than the predetermined value (ie, NO), the tablet T is determined to be a defective product, and the process proceeds to step S20.

  In addition, when back printing is not performed as described above, the steps S17 and S18 can be omitted, and the time can be further reduced. Furthermore, if the level of the position and angle of the tablet T is negligible before and after the printing process, the information stored in the storage unit 55 in step S4 can be used without performing step S12. In this case, the time can be further shortened. In addition, since it is not necessary to perform pattern matching for each predetermined angle by relatively rotating the print image and the reference pattern in step S18, the time can be further reduced.

  The non-defective tablet T is transported with the movement of the transport belt 21 a and passes above the drying unit 26. At this time, the ink applied to the tablet T is dried by the drying unit 26 while the tablet T passes over the drying unit 26, and the tablet T with the dried ink is conveyed along with the movement of the conveyance belt 21a. Go.

  In step S <b> 20, the defective tablet T is dropped from the transport belt 21 a by the gas ejected from the ejection nozzle 27 a and is collected by the collection unit 27. On the other hand, the non-defective tablet T is transported along with the movement of the transport belt 21a, passes below the injection nozzle 27a, and is located near the end of the transport belt 21a on the first pulley 21 side. At this position, the suction action does not work on the tablet T, and the tablet T is released from the state of being held by the transport belt 21a and passed from the transport belt 21a of the first printing unit 20 to the transport belt 31a of the second printing unit 30. It is.

  Thereafter, the second printing unit 30 also performs the printing and inspection processes as described above. The non-defective tablet T is transported along with the movement of the transport belt 31a, passes below the injection nozzle 37a, and is located near the end of the transport belt 31a on the second pulley 31c side. At this position, the suction action does not act on the tablet T, and the tablet T is released from the state of being held by the transport belt 31a, falls from the transport belt 31a, and is stored in the tablet storage unit 40. On the other hand, the defective tablet T is dropped from the conveyor belt 31 a by the gas ejected from the ejection nozzle 37 a and is collected by the collection unit 37.

  In such a printing process and inspection process, the presence / absence of a secant on the upper surface of the tablet T, that is, the front / back determination of the tablet T is determined by the determination unit 51 based on the reflection intensity information of the laser light acquired from the detection units 22 and 32. Is done. At this time, it is possible to determine the front and back of the tablet T from the reflection intensity information of the laser beam without requiring special processing such as image processing. Since image processing for determining the front and back of the tablet T is not necessary, the processing time can be shortened accordingly. Accordingly, by determining the front and back of the tablet T using the detection units 22 and 32, it is possible to improve the printing efficiency and the inspection efficiency. Further, when it is detected that there is no secant of the tablet T, image processing related to the secant, for example, secant detection processing and secant angle determination processing (see FIGS. 4 and 5) is omitted from the plurality of image processes. As a result, the processing time required for image processing can be shortened, and the printing efficiency and inspection efficiency can be reliably improved.

  As described above, according to the first embodiment, when the detection unit 22 or 32 detects the presence or absence of the tablet T, and the detection unit 22 or 32 detects that there is a secant of the tablet T, the imaging unit 23 Alternatively, when a plurality of image processes are performed on the image obtained by 33 and the detection unit 22 or 32 detects that there is no secant line of the tablet T, the image process related to the secant line of the tablet T from each of the image processes described above Is omitted. This eliminates the need for image processing for determining the presence or absence of a secant from the image captured by the imaging unit 23 or 33. Furthermore, when there is no secant of the tablet T, image processing relating to the secant is omitted. Therefore, the processing time can be shortened, and the printing efficiency and the inspection efficiency can be improved.

  Further, the detection unit 22 emits laser light toward the tablet T on the transport unit 21, and the laser light reflected by the tablet T is received. Thereafter, the determination unit 51 determines whether or not there is a secant on the upper surface of the tablet T on the transport unit 21 based on the reflection intensity (reflection intensity pattern) of the received laser beam. As a result, it is possible to determine the front and back of the tablet T based on the reflection intensity information of the laser beam, so image processing for determining the front and back of the tablet T is not required, and the processing time is reliably shortened accordingly. can do.

(Second Embodiment)
A second embodiment will be described with reference to FIGS. In the second embodiment, differences (third detection unit 14 and third imaging unit 15) from the first embodiment will be described, and other descriptions will be omitted.

  Here, in the second embodiment, when printing is performed on the back of the tablet T, for example, along the dividing line on the opposite surface with respect to the surface without the dividing line, as in the case of printing on the front surface of the tablet T. Printing is performed or printing is performed while avoiding the position facing the secant on the opposite surface. For this reason, it is necessary to determine whether or not there is a secant with respect to one side of the tablet T in the tablet supply unit 10 on the upstream side of the first printing unit 20.

  As shown in FIG. 6, in the second embodiment, the detection unit 14 is provided below the delivery feeder 13. The detection unit 14 facing the delivery feeder 13 is disposed at a position where the lower surface (for example, substantially the center of the lower surface) of the tablet T conveyed by the delivery feeder 13 can be irradiated with laser light. As the detection unit 14, for example, various laser sensors (laser displacement meters) such as a reflection type laser sensor can be used. Various shapes such as spots and lines can be used as the beam shape of the laser light. In addition, the conveyance direction of the delivery feeder 13 is the direction of arrow A3 in FIG. 6 (conveyance direction A3).

  Such a detection unit 14 emits laser light toward the tablet T on the delivery feeder 13, receives laser light (reflected light) reflected by the tablet T, and sets the reflection intensity of the laser light to the control unit 50. Send. The reflection intensity of the laser light is information indicating a separation distance between the detection unit 14 and the surface of the delivery feeder 13 on the detection unit 14 side or the lower surface of the tablet T on the delivery feeder 13. Moreover, since the detection part 14 detects the presence or absence of the tablet T on the delivery feeder 13 by light projection / reception of a laser beam, it functions also as a trigger sensor of the 3rd imaging part 15 located downstream. The detection unit 14 is electrically connected to the control unit 50, and transmits position information (position in the transport direction A1) of the tablet T and laser beam reflection intensity information to the control unit 50.

  The third imaging unit 15 is positioned downstream of the detection unit 14 in the transport direction A3 and is provided below the delivery feeder 13. The third imaging unit 15 performs imaging at a timing based on the position information of the tablet T described above, acquires an image including the lower surface of the tablet T (image for printing), and transmits the acquired image to the control unit 50. To do. As the third imaging unit 15, for example, various imaging units having an imaging element such as a CCD or a CMOS can be used. The third imaging unit 15 is electrically connected to the control unit 50, and its driving is controlled by the control unit 50. Note that illumination for imaging is also provided as necessary.

(Printing and inspection processing)
Next, the printing and inspection process (printing and inspection process) performed by the tablet printing apparatus 1 will be described with reference to FIG. FIG. 7 shows the flow of the printing process of the tablet supply unit 10 and the first printing unit 20. Since the inspection process of the first printing unit 20 after this printing process and the printing and inspection process of the second printing unit 30 are the same as those in the first embodiment, description thereof will be omitted.

  As shown in FIG. 7, in step S <b> 31, the tablets T start to be sequentially supplied from the hopper 11 to the alignment feeder 12 and are aligned in a line by the alignment feeder 12. The tablets T moving in a row are sucked by the delivery feeder 13 and moved on the delivery feeder 13.

  In step S32, the tablet T on the delivery feeder 13 is detected by the detection unit 14 located below the delivery feeder 13 (sensor 3). Thereby, the position information of the tablet T (position in the transport direction A3) and the reflection intensity information of the laser beam are acquired and input to the control unit 50. Further, the determination unit 51 determines whether or not there is a secant on the lower surface of the tablet T on the delivery feeder 13 based on the reflection intensity information of the laser beam. The position information and front / back information of the tablets T are stored in the storage unit 55 and used in post-processing.

  In step S33, the tablet T on the delivery feeder 13 is imaged by the third imaging unit 15 (camera 3). The lower surface of the tablet T is imaged by the third imaging unit 15 at a timing based on the position information of the tablet T described above, and the captured image is transmitted to the control unit 50.

  Here, the tablets T on the delivery feeder 13 are released from the holding state by suction at the end of the first printing unit 20 on the side of the conveying belt 21a and are sequentially supplied to the conveying belt 21a. The transport belt 21a is moved in the transport direction A1 by the rotation of the first pulley 21b and the second pulley 21c by the motor 21d. For this reason, the tablets T supplied onto the conveyor belt 21a are conveyed in a line on the conveyor belt 21a.

  In step S34, based on the front / back information stored in the storage unit 55, whether or not the tablet T on the delivery feeder 13 is the back side (whether or not the tablet T is the front side in the next step) is the print processing unit. 53. If it is determined that the tablet T is the back side (YES), the process proceeds to step S35, and the process in the first printing unit 20 is started. On the other hand, when it is determined that the tablet T is not the back but the front (NO), the process proceeds to step S41, and the process in the first printing unit 20 is started. When the tablet T is a table as described above, the position determination process of the tablet T in step S35 and the imaging process of the tablet T in step S36 are omitted. In addition, the tablet T which is the back on the delivery feeder 13 becomes a table on the transport belt 21a of the next process. On the other hand, the tablet T which is a table on the delivery feeder 13 becomes the back on the transport belt 21a of the next process.

  In step S35, the tablet T on the transport belt 21a is detected by the detection unit 22 (sensor 1). That is, the detection unit 22 detects the tablet T with the front surface (the surface with the secant line) facing upward on the transport belt 21a. Thereby, the position information (position in the transport direction A1) of the tablet T is acquired and input to the control unit 50. The position information of the tablet T is stored in the storage unit 55 and used in post-processing. In addition, since the front and back information of the tablet T is obtained in the above-mentioned step S32, it is not necessary to acquire the reflection intensity information of the laser beam in order to obtain the front and back information of the tablet T in this step S35.

  Steps S36 to S40 perform imaging by the first imaging unit 23 and further image processing on the image captured by the first imaging unit 23. The processing itself is step S3 according to the first embodiment. This is the same as S4, S6, S7 and S8. Steps S41 to S44 perform image processing on the image captured by the third imaging unit 15, and the processing itself is the same as steps S4, S6, S7, and S9 according to the first embodiment. . Step S45 is also the same as step S10 according to the first embodiment.

  In such a printing or inspection process, the presence or absence of a secant on the lower surface or the upper surface of the tablet T, that is, the front / back determination of the tablet T is performed by the determination unit 51 based on the reflection intensity information of the laser light acquired from the detection unit 14 or 22. Determined. At this time, it is possible to determine the front and back of the tablet T from the reflection intensity information of the laser beam without requiring special processing such as image processing. Since image processing for determining the front and back of the tablet T is not necessary, the processing time can be shortened accordingly. Therefore, by using the detection unit 14 or 22 to determine the front and back of the tablet T, it is possible to improve printing efficiency and inspection efficiency. Further, when it is detected that there is no secant of the tablet T, image processing related to the secant, for example, a secant angle determination process (see FIG. 5) is omitted from the plurality of image processes. As a result, the processing time required for image processing can be shortened, and the printing efficiency and inspection efficiency can be reliably improved.

  As described above, according to the second embodiment, the same effect as that of the first embodiment can be obtained.

(Other embodiments)
In each of the above-described embodiments, the first printing unit 20 and the second printing unit 30 exemplify printing on both surfaces of the tablet T. However, the present invention is not limited to this. For example, the first printing unit 20 Alternatively, the second printing unit 30 may print only on one side (front or back) of the tablet T.

  In each of the above-described embodiments, each conveyance lane of the first printing unit 20 and the second printing unit 30 is exemplified as one lane. However, the present invention is not limited to this. For example, two lanes or three lanes Four lanes may be used, and the number is not particularly limited.

  Moreover, in each above-mentioned embodiment, although the conveyance part which has the holding mechanism which attracts | sucks and hold | maintains the tablet T was illustrated as the conveyance part 21 or 31, it does not restrict to this but uses various conveyance mechanisms. Is possible. Further, as an example of the holding mechanism, the tablet T is held by the circular suction holes H arranged in the transport direction. However, the holding mechanism is not limited to this. For example, a slit-like suction hole H extending in the transport direction is used. Is also possible.

  Further, in each of the above-described embodiments, the detection units 22 and 32 are conveyed by the delivery feeder 13 as the detection unit that irradiates the upper surface of the tablet T on the conveyance belts 21a and 31a with laser light, and the detection unit 14. Although the detection part which irradiates the laser beam to the lower surface of the tablet T to be illustrated is illustrated, the present invention is not limited to this. For example, the laser light may be irradiated on the upper part of the side surface of the tablet T, or the laser light may be irradiated on the lower part of the side surface of the tablet T. Moreover, you may make it irradiate a laser beam to the full width of the height direction of the side surface of the tablet T. FIG.

  Further, in each of the above-described embodiments, the detection unit that irradiates laser light is exemplified as the detection unit 14, 22, and 32. However, the detection unit is not limited to this, and any device that can measure the distance may be used. It is also possible to use a directional (beam) ultrasonic rangefinder such as sonar. In addition, a detection camera can be used as the detection units 14, 22, and 32. In this case, for example, by preparing an image processing unit dedicated to the camera for detection, the processing load can be prevented from being applied to the original image processing.

  In each of the above-described embodiments, one detection unit 22 and 32 is provided for one transport belt 21a and 31a, and one detection unit 14 is provided for the delivery feeder 13. However, the present invention is not limited to this, and for example, two or more may be provided. That is, a plurality of detection units 14, 22, and 32 are arranged in a direction intersecting the conveyance direction A <b> 1 (for example, a direction orthogonal), and the presence / absence of the dividing line of the tablet T is determined from information from each detection unit 14, 22, and 32. Is possible. Thereby, the precision of the front-and-back determination of the tablet T can be improved compared with the case where the detection parts 14, 22, and 32 are one. In addition to the front / back determination of the tablet T, it is also possible to detect the angle of the secant (posture information).

  In each of the above-described embodiments, the timing of printing and inspection imaging is taken based on the detection units 14, 22, and 32. However, the present invention is not limited to this, and for example, the first imaging units 23 and 33 The timing of printing may be taken based on this, or the timing of inspection imaging may be taken based on the execution of printing.

  In each of the above-described embodiments, the use of one print head as the print head 24 or 34 has been exemplified. However, the present invention is not limited to this. For example, a plurality of print heads can be used. The number is not particularly limited. Furthermore, as an inkjet print head, a print head in which nozzles N are arranged in a row is illustrated, but the present invention is not limited to this, and for example, a print head in which nozzles N are arranged in a plurality of rows can be used.

  In the second embodiment, the detection unit 32 and the second imaging unit 33 can be used. However, the present invention is not limited to this. For example, the detection unit 32 and the second imaging unit 33 are removed. You can also When the detection unit 32 and the second imaging unit 33 are removed, the information of step S32, step S37, and step S39 is used in printing by the second printing unit 30. Further, these pieces of information and the information in steps S12 and S14 are also used in the inspection by the second printing unit 30. By doing so, printing and inspection time can be shortened.

  Here, as the above-mentioned tablet, a tablet used for medicine, food and drink, washing, industrial use or fragrance can be included. Examples of the tablet include a naked tablet (plain tablet), a sugar-coated tablet, a film-coated tablet, an enteric tablet, a gelatin-encapsulated tablet, a multilayer tablet, and a dry-coated tablet. Furthermore, various capsule tablets such as hard capsules and soft capsules can be included in the tablets. In addition, the tablet has various shapes such as a disk shape, a lens shape, a triangle shape, and an oval shape.

  In addition, when the tablet to be printed is for medical use or food and drink, edible ink is suitable as the ink to be used. Specifically, edible pigments such as amaranth, erythrosine, new coccin (above, red), tartrazine, sunset yellow FCF, β-carotene, crocin (above, yellow), brilliant blue FCF, indigo carmine (above, blue) And the like, and these are dispersed or dissolved in a vehicle, and if necessary, a pigment dispersant (surfactant) may be blended. As the edible ink, any of synthetic dye ink, natural dye ink, dye ink, and pigment ink may be used.

  As mentioned above, although some embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 Tablet printer 14 Detection part 15 Imaging part 21 Conveyance part 22 Detection part 23 Imaging part (1st imaging part)
24 print head 25 imaging unit (second imaging unit)
31 Conveyance unit 32 Detection unit 33 Imaging unit (first imaging unit)
34 Print Head 35 Imaging Unit (Second Imaging Unit)
52 Image processing part T Tablet

Claims (8)

A transport unit for transporting a tablet having a secant on one side ;
An imaging unit that captures the tablets being conveyed by pre-Symbol conveying section,
A detection unit that is upstream of the imaging unit and outputs a signal corresponding to the shape of the surface of the tablet, which is imaged by the imaging unit;
A determination unit that determines whether or not there is a secant on the surface of the tablet based on the output of the detection unit;
A processing unit for processing an image obtained by the imaging unit;
A print head for printing on the tablets conveyed by the conveying unit;
With
The processing unit, when said secant to the surface of the tablet is determined that there the determination unit performs a plurality of image processing on the obtained said image by the imaging unit, the by the determination unit When it is determined that there is no secant on the surface of the tablet, the tablet printing apparatus performs the remaining image processing by omitting the image processing related to the secant of the tablet from the plurality of image processing. The tablet printing apparatus according to claim 1, wherein the detection unit is a laser sensor that detects a separation distance between the surface of the tablet and the detection unit. The plurality of image processes include a center-of-gravity determination process for calculating an offset amount between the center of gravity of the tablet and a predetermined reference coordinate center, a secant detection process for detecting a pattern corresponding to the secant of the tablet, An angle determination process for calculating the angle of the secant,
The processing unit, wherein when it is determined that there is no secant to the surface of the tablet by the determining unit, according to claim 1 or claim 2, characterized in that omitting the secant detection processing and the angle judging processing The tablet printing apparatus described in 1. The plurality of image processes include a center-of-gravity determination process for calculating an offset amount between the center of gravity of the printed tablet and a predetermined reference coordinate center, and an angle determination process for calculating an angle of a dividing line of the printed tablet. A print extraction process for extracting a printed pattern of the printed tablet, and a pattern matching process for comparing the extracted print pattern and a reference pattern,
The processing unit, wherein when it is detected that there is no secant to the surface of the tablet by the determining unit, according to any one of claims 1 to 3, characterized in that omitting the angle judging processing Tablet printing equipment. Transporting a tablet having a secant on one side ;
A step of imaging the tablets fed transportable,
Before imaging the tablet, determining whether or not the secant is present on the surface of the tablet imaged by the imaging step;
Processing an image obtained by the imaging;
Printing on the tablets to be conveyed;
Have
In the step of processing the image, if the secant to the surface of the tablet is determined that there is carried out a plurality of image processing on the obtained said image by the imaging, secant to the surface of the tablet If it is determined that there is no, tablet printing method and performing the rest of the image processing from the plurality of image processing by omitting the image processing according to the secant of the tablet. In the step of determining whether or not the secant is present on the surface of the tablet, a step of detecting a separation distance between the laser sensor and the surface of the tablet by a laser sensor and determining based on the detected value The tablet printing method according to claim 5, comprising: The plurality of image processes include a center-of-gravity determination process for calculating an offset amount between the center of gravity of the tablet and a predetermined reference coordinate center, a secant detection process for detecting a pattern corresponding to the secant of the tablet, An angle determination process for calculating the angle of the secant,
In the step of processing the image, if the secant to the surface of the tablet is determined not to, in claim 5 or claim 6, characterized in omitting the secant detection processing and the angle judging processing The tablet printing method as described. The plurality of image processes include a center-of-gravity determination process for calculating an offset amount between the center of gravity of the printed tablet and a predetermined reference coordinate center, and an angle determination process for calculating an angle of a dividing line of the printed tablet. A print extraction process for extracting a printed pattern of the printed tablet, and a pattern matching process for comparing the extracted print pattern and a reference pattern,
In the step of processing the image, if the secant to the surface of the tablet is determined not to, according to any of claims 5 to 7, characterized in omitting the angle judging processing Tablet printing method.

Images