Tablet printing apparatus and tablet printing method

Abstract

Provided is a tablet printing device and a tablet printing method that can improve the accuracy of inspection of a tablet on which a code is printed with information. The tablet printing device of an embodiment includes a printing head that performs printing on a tablet; a control device (40) that controls the printing head; and a camera device that captures a tablet on which printing has been performed by the printing head. The control device (40) controls the printing head to print a code generated on the basis of original data and determines whether data read from the code included in an image obtained by the camera device is identical to the original data.

Description

Technical Field

[0001] The present invention relates to a tablet printing apparatus and a tablet printing method. Background Technology

[0002] Previously, inkjet printrs were used to print characters and other identification information on tablets. By printing identification information directly on the tablets, the tablet's identification information can be confirmed even after the tablet has been removed from packaging containers such as press-through packs (PTP) blister packs.

[0003] However, in tablets intended for oral consumption, the amount of information that can be printed on the tablet is limited due to its small size. To address this, converting the desired information into a code, such as a Quick Response (QR) code (registered trademark), and printing the QR code on the tablet increases the amount of information that can be displayed.

[0004] Tablets printed with this type of QR code are typically photographed by a camera to determine the quality of the QR code printing. Methods for determining quality include, for example, pattern matching. Generally, QR codes have error correction capabilities, so even with minor printing defects or stains, the information can still be read.

[0005] However, when using pattern matching for inspection, although there are no problems reading information from the QR codes printed on the tablets, tablets with these QR codes are sometimes judged as defective and rejected, thus reducing the yield. Furthermore, in pattern matching inspection, consider the following scenario: although tablets with QR codes are judged as good, the QR code reader reads incorrect information from the QR codes printed on the tablets.

[0006] [Existing Technical Documents]

[0007] [Patent Literature]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 2019-58220 Summary of the Invention

[0009] [The problem the invention aims to solve]

[0010] The problem to be solved by the present invention is to provide a tablet printing apparatus and tablet printing method that can improve the inspection accuracy of tablets with printed information.

[0011] [Technical means to solve the problem]

[0012] The tablet printing apparatus of the present invention includes: a printing head for printing on a tablet; a control device for controlling the printing head; and an imaging device for imaging the tablet printed by the printing head, wherein the control device controls the printing head to print a code generated based on original data and determines whether data read from the code contained in the image obtained by the imaging device is consistent with the original data.

[0013] The tablet printing method according to an embodiment of the present invention includes: a control device controlling a print head that prints on a tablet to print a code generated based on original data; and determining whether data read from the code contained in an image obtained using an imaging device is consistent with the original data, wherein the imaging device takes an image of the tablet printed using the print head.

[0014] [The effects of the invention]

[0015] The embodiments of the present invention can improve the inspection accuracy of tablets with printed information. Attached Figure Description

[0016] Figure 1 This is a diagram illustrating an example of the schematic structure of the tablet printing apparatus according to the first embodiment.

[0017] Figure 2 This is a diagram showing an example of the schematic structure of the printing apparatus according to the first embodiment.

[0018] Figure 3 This is a diagram illustrating an example of the schematic structure of the control device according to the first embodiment.

[0019] Figure 4 This is a diagram illustrating an example of a QR code used in the first embodiment.

[0020] Figure 5 This is a flowchart illustrating an example of the printing process in the first embodiment.

[0021] Figure 6 This is a diagram illustrating an example of a QR code and string in the second embodiment.

[0022] [Explanation of Symbols]

[0023] 1: Tablet printing device

[0024] 10: Supply device

[0025] 11: Hopper

[0026] 12: Arrangement feeder

[0027] 13: Transfer feeder

[0028] 20: First Printing Unit

[0029] 21, 51: Transport Department

[0030] 21a, 51a: Conveyor belt

[0031] 21b, 51b: Drive pulley

[0032] 21c, 51c: Driven pulley

[0033] 21d, 51d: Motor

[0034] 21e, 51e: Position detectors

[0035] 21f, 51f: Suction chamber

[0036] 21g: Suction port

[0037] 22, 52: Testing Department

[0038] 23, 53: First Shooting Unit

[0039] 24, 54: Inkjet head

[0040] 24a: Nozzle

[0041] 25, 55: Second shooting section

[0042] 27, 57: Drying section

[0043] 30: Recycling device

[0044] 31: Recycling Department

[0045] 31a, 32a, 33a: Injection nozzles

[0046] 31b, 32b, 33b: Recycling bins

[0047] 32: Defective Product Recycling Department

[0048] 33: Good Product Recycling Department

[0049] 40: Control device

[0050] 40a: Input device

[0051] 40b: Output device

[0052] 41: Image Processing Department

[0053] 42: Storage Department

[0054] 43: Control Department

[0055] 44: Code Generation Department

[0056] 50: Second printing apparatus

[0057] A1, A2: Conveying direction

[0058] B1: QR code

[0059] B1a, B1b, B1c: Location markers

[0060] C1: Character (image of a character)

[0061] S1, S2, S3, S4, S5, S6, S7, S8, S9, S10: Steps

[0062] T: Tablets

[0063] X, Y, θ: Direction Detailed Implementation

[0064] <First Implementation>

[0065] Reference Figures 1 to 5 The first implementation method will be described below.

[0066] (Example of the configuration of a tablet printing apparatus)

[0067] like Figure 1 As shown, the tablet printing apparatus 1 of the first embodiment includes a supply device 10, a first printing device 20, a second printing device 50, a recycling device 30, and a control device 40.

[0068] The supply device 10 includes a hopper 11, an arranging feeder 12, and a transfer feeder 13. The supply device 10 is positioned at one end of the first printing apparatus 20 and is configured to supply tablets T, which are the objects to be printed, to the first printing apparatus 20. The hopper 11 holds a large number of tablets T and sequentially supplies the held tablets T to the arranging feeder 12. The arranging feeder 12 arranges the supplied tablets T into a row and conveys them toward the transfer feeder 13 in the conveying direction A1 (clockwise). The arranging feeder 12 can be, for example, a belt conveyor or a vibrating feeder. The transfer feeder 13 sequentially draws tablets T arranged in a row on the arranging feeder 12 from above and holds each tablet T, conveying the held tablets T in a row to the first printing apparatus 20 and transferring them thereto. The transfer feeder 13 can be, for example, a belt conveyor. The conveying mechanism of the transfer feeder 13 rotates in the conveying direction A2 (counterclockwise). The supply device 10 is electrically connected to the control device 40, and the drive of the supply device 10 is controlled by the control device 40.

[0069] The first printing apparatus 20 includes a conveying unit 21, a detection unit 22, a first imaging unit 23, an inkjet head 24, a second imaging unit 25, and a drying unit 27. The inkjet head 24 is an example of a print head (printing unit), and the second imaging unit 25 is an example of an imaging device.

[0070] The conveying unit 21 includes a conveyor belt 21a, a drive pulley 21b, multiple driven pulleys 21c, a motor 21d, a position detector 21e, and a suction chamber 21f. The conveyor belt 21a is a loop belt and is mounted on the drive pulley 21b and each driven pulley 21c. The drive pulley 21b and each driven pulley 21c are rotatably mounted on the main body of the device (not shown), and the drive pulley 21b is connected to the motor 21d. The motor 21d is electrically connected to the control device 40, and the drive of the motor 21d is controlled by the control device 40. The position detector 21e is an encoder or similar device and is mounted on the motor 21d. The position detector 21e is electrically connected to the control device 40 and sends detection signals to the control device 40. The conveying unit 21 causes the conveyor belt 21a and each driven pulley 21c to move together by the rotation of the drive pulley 21b based on the motor 21d, and conveys the tablets T on the conveyor belt 21a along the conveying direction A1 (clockwise direction).

[0071] like Figure 2 As shown, multiple circular suction holes 21g are formed on the conveyor belt 21a. These suction holes 21g are through holes for adsorbing the tablet T and are arranged in a row along the conveying direction A1 to form a conveying path. Each suction hole 21g is connected to a suction chamber 21f (see reference). Figure 1 The pump is connected to the suction chamber 21f via a suction path (not shown), and suction force is obtained through the suction chamber 21f. The pump is connected to the suction chamber 21f via a suction pipe (not shown), and the pump depressurizes the suction chamber 21f by operating the pump. The suction pipe is connected to the approximate center of the side of the suction chamber 21f (the plane parallel to the transport direction A1). In addition, the pump is electrically connected to the control device 40, and the pump drive is controlled by the control device 40. When the pressure is reduced in the suction chamber 21f, the tablet T placed on each suction hole 21g of the transport belt 21a is drawn in by the suction hole 21g and held on the transport belt 21a.

[0072] The detection unit 22 is positioned downstream of the location where the supply device 10 is located in the conveying direction A1, and is positioned above the conveying path where the suction holes 21g are arranged. The detection unit 22 detects tablets T (the arrival of tablet T) that have reached a detection position directly below it, i.e., tablets T on the conveyor belt 21a, at a position in the conveying direction A1, by projecting and receiving laser light. For example, a displacement sensor can be used as the detection unit 22. Alternatively, various laser sensors, such as reflective laser sensors, can be used as displacement sensors. The detection unit 22 is electrically connected to the control device 40 and sends detection signals to the control device 40.

[0073] The first imaging unit 23 is positioned downstream of the location of the detection unit 22 in the transport direction A1, and is positioned above the transport path in which the suction holes 21g are arranged. Based on the position information of the tablet T in the transport direction A1 detected by the detection unit 22, the first imaging unit 23 takes a picture at a first shooting moment when the tablet T reaches the shooting position directly below the first imaging unit 23, acquiring a first image including the upper surface of the tablet T, and sends the acquired first image to the control device 40. The first image is used to detect the tablet T in the X, Y, and θ directions (refer to...). Figure 2 The position of the first imaging unit 23 is specified. Various cameras with imaging elements such as charge-coupled devices (CCDs) or complementary metal oxide film semiconductors (CMOS) can be used as the first imaging unit 23. The first imaging unit 23 is electrically connected to the control device 40, and the drive of the first imaging unit 23 is controlled by the control device 40. Furthermore, illumination for imaging is also provided as needed.

[0074] Here, the positions of tablet T in the X and Y directions are, for example, positions in the XY coordinate system relative to the center (reference position) of the imaging area of ​​the first imaging unit 23. Additionally, the position in the θ direction represents, for example, the degree of rotation of tablet T within the horizontal plane along the XY plane of the imaging area of ​​the first imaging unit 23. This position in the θ direction is detected when tablet T has dividing lines, or when tablet T is shaped as an ellipse, oblong, triangular, quadrilateral, etc., indicating that tablet T has a directional shape. Furthermore, the X and Y directions are positions in the horizontal direction.

[0075] The inkjet head 24 is positioned downstream of the location where the first imaging section 23 is located in the transport direction A1, and is positioned above the transport path in which the suction holes 21g are arranged. The inkjet head 24 has a plurality of (e.g., hundreds to thousands) nozzles 24a (see reference) Figure 2The direction in which the nozzles 24a are arranged in a row (nozzle array) is set to be orthogonal to the transport direction A1 in the horizontal plane (an example of intersection). The inkjet head 24 ejects ink individually from each nozzle 24a through the action of the drive element of each nozzle 24a. As the inkjet head 24, various inkjet printing heads with drive elements such as piezoelectric elements, heating elements, or magnetostrictive elements can be used. The inkjet head 24 is electrically connected to the control device 40, and the drive of the inkjet head 24 is controlled by the control device 40.

[0076] The second imaging unit 25 is positioned downstream of the location where the inkjet head 24 is located in the transport direction A1, and is positioned above the transport path where the suction holes 21g are arranged. Based on the position information of the tablet T in the transport direction A1 detected by the detection unit 22, the second imaging unit 25 takes a picture at a second imaging timing when the tablet T reaches an imaging position directly below the second imaging unit 25, and acquires a second image including the upper surface of the tablet T. The acquired second image is then sent to the control device 40. The second image can be used to inspect the printed pattern on the tablet T. Similar to the first imaging unit 23, various cameras with imaging elements such as CCD or CMOS can be used as the second imaging unit 25. The second imaging unit 25 is electrically connected to the control device 40, and its operation is controlled by the control device 40. Illumination for imaging is also provided as needed.

[0077] The drying section 27 is positioned opposite the conveyor belt 21a, for example, below the conveyor belt 21a. The drying section 27 dries the ink on each tablet T coated on the conveyor belt 21a. The drying section 27 can be any type of dryer, such as a blower that uses air or other gases for drying, a heater that uses radiant heat for drying, or a blower that combines gases and a heater to use warm or hot air for drying. The drying section 27 is electrically connected to the control device 40, and its operation is controlled by the control device 40.

[0078] Here, the first printing device 20 and the second printing device 50 are configured such that portions of the conveying section 21 and the conveying section 51 overlap vertically. The tablet T printed by the upper first printing device 20 is transferred to the lower second printing device 50, thereby printing both sides of the tablet T. Normally, in order to smoothly transfer the tablet T from the first printing device 20 to the second printing device 50, the conveying speed of the first printing device 20 and the conveying speed of the second printing device 50 are always the same.

[0079] The second printing apparatus 50 has the same structure as the first printing apparatus 20. That is, the second printing apparatus 50 includes a conveying unit 51, a detection unit 52, a first imaging unit 53, an inkjet head 54, a second imaging unit 55, and a drying unit 57. The conveying unit 51 includes a conveyor belt 51a, a drive pulley 51b, multiple driven pulleys 51c, a motor 51d, a position detector 51e, and a suction chamber 51f. The conveying unit 51 conveys the tablet T on the conveyor belt 51a along the conveying direction A2 (counterclockwise). The inkjet head 54 is an example of a printing head (printing unit), and the second imaging unit 55 is an example of an imaging device. Furthermore, since the components constituting the second printing apparatus 50 have essentially the same structure as those constituting the first printing apparatus 20, their description is omitted.

[0080] The recycling device 30 is positioned downstream of the location where the drying section 57 is located in the conveying direction A2, and is located below the conveying section 51. The recycling device 30 includes a reusable product recycling section 31, a defective product recycling section 32, and a good product recycling section 33. The recycling device 30 recycles tablets T as reusable products through the reusable product recycling section 31, recycles tablets T as defective products through the defective product recycling section 32, and recycles tablets T as good products through the good product recycling section 33. For example, reusable products are reusable tablets that are undamaged and free of foreign matter (non-printed tablets). Defective products are non-printed tablets with foreign matter or undamaged, non-defective printed tablets (printed tablets), while good products are undamaged, non-defective, and free of foreign matter (printed tablets). Furthermore, the arrangement order of the reusable product recycling section 31, the defective product recycling section 32, and the good product recycling section 33 in the conveying direction A2 is not limited to... Figure 1 The arrangement shown can also be changed as appropriate. The recycling device 30 is electrically connected to the control device 40, and the drive of the recycling device 30 is controlled by the control device 40.

[0081] The reusable product recycling section 31 has a spray nozzle 31a and a recycling bin 31b. Similarly, the defective product recycling section 32 has a spray nozzle 32a and a recycling bin 32b. The good product recycling section 33 has a spray nozzle 33a and a recycling bin 33b. These spray nozzles 31a, 32a, and 33a have essentially the same structure, and the recycling bins 31b, 32b, and 33b also have essentially the same structure. Therefore, the spray nozzle 31a and the recycling bin 31b will be described as representative examples.

[0082] The spray nozzle 31a and the recovery box 31b are positioned facing each other along the conveying path, which is separated by suction holes on the conveyor belt 51a. The spray nozzle 31a is disposed within the suction chamber 51f and sprays gas (e.g., air) towards the conveyor belt 51a, causing the tablet T to fall from the conveyor belt 51a. At this time, the gas sprayed from the spray nozzle 31a comes into contact with the tablet T through the suction holes of the conveyor belt 51a. The spray nozzle 31a is electrically connected to the control device 40, and the drive of the spray nozzle 31a is controlled by the control device 40. The recovery box 31b is located directly below the spray nozzle 31a and below the conveyor section 51. The recovery box 31b receives and contains the tablet T that falls from the conveyor belt 51a due to the gas sprayed from the spray nozzle 31a.

[0083] Here, tablets T are conveyed by the reusable product collection section 31 and the defective product collection section 32 as the conveyor belt 51a moves, and reach a position near the end of each driven pulley 51c on the conveyor belt 51a. At this position, the suction effect no longer acts on the tablets T, but gas is blown onto the tablets T from above through the spray nozzle 33a, and the tablets T fall from the conveyor belt 51a. Therefore, by providing the spray nozzle 33a, the tablets T can be reliably dropped from the conveyor belt 51a. The collection box 33b receives and contains the tablets T that have fallen from the conveyor belt 51a due to the gas sprayed from the spray nozzle 33a.

[0084] The control device 40 controls various parts of the tablet printing apparatus 1, such as the supply device 10, the first printing device 20, the second printing device 50, and the recycling device 30, based on various information and programs. Furthermore, the control device 40 receives detection data (e.g., detection signals) sent from the position detector 21e or detection unit 22 of the conveying unit 21, and the position detector 51e or detection unit 52 of the conveying unit 51, and also receives image data sent from the first imaging unit 23 or the second imaging unit 25, the first imaging unit 53, and the second imaging unit 55. The control device 40 is implemented, for example, by electronic circuits such as integrated circuits or by a computer.

[0085] (Example of control device configuration)

[0086] Next, refer to Figure 3 To illustrate the configuration example of the control device 40.

[0087] like Figure 3 As shown, the control device 40 includes an image processing unit 41, a storage unit 42, a control unit 43, and a code generation unit 44. An input device 40a and an output device 40b are connected to the control device 40. The input device 40a is implemented, for example, through a switch, touchscreen, keyboard, mouse, etc. The output device 40b is implemented, for example, through a display, lamp, measuring instrument, etc.

[0088] The image processing unit 41 imports a first image captured by the first imaging unit 23 or 53 and a second image captured by the second imaging unit 25 or 55, and processes the images using known image processing techniques. For example, the image processing unit 41 processes the first image obtained from the first imaging unit 23 to obtain information on whether the tablet T is damaged or has foreign matter attached, and the position of the tablet T in the X, Y, and θ directions. Additionally, the image processing unit 41 processes the second image obtained from the second imaging unit 25 to obtain image information of the printed pattern on the tablet T. The image processing unit 41 then sends the obtained information on whether the tablet T is damaged or has foreign matter attached, the position information of each tablet T in the X, Y, and θ directions, and further, the image information of the printed pattern on each tablet T to the control unit 43.

[0089] The storage unit 42 stores various programs and information. The storage unit 42 is implemented, for example, by semiconductor memory elements such as Random Access Memory (RAM) and Flash Memory, or by storage devices such as hard disks and optical discs. The storage unit 42 stores production data (production information), printing-related data, transport speed data, etc. Production data refers to data that changes as the printed tablets T are produced (manufactured). For example, batch numbers can be listed as production data. Production data can be generated based on information input by the user using the input device 40a, or it can be automatically generated by the control unit 43.

[0090] The control unit 43 is, for example, a central processing unit (CPU), a microcontroller (MCU), a microprocessor (MPU), or a computer, and controls the various components. The control unit 43 can be implemented through one or both hardware and software. For example, the control unit 43 controls the supply device 10, the first printing device 20, the second printing device 50, the recycling device 30, the image processing unit 41, the storage unit 42, the code generation unit 44, etc., based on various information or programs stored in the storage unit 42. Furthermore, the control unit 43 receives detection signals from the position detector 21e or the detection unit 22 of the conveying unit 21, and the position detector 51e or the detection unit 52 of the conveying unit 51.

[0091] The code generation unit 44, based on the batch number (an example of production data) used as raw data, such as... Figure 4 The generated QR code B1 is shown. QR code B1 contains multiple location markers (cutout symbols) B1a, B1b, and B1c. In Figure 4In this example, only the QR code B1 is printed on the tablet T. Furthermore, the control unit 43 converts the QR code B1 generated by the code generation unit 44 into a printing pattern (e.g., raster data), and controls the inkjet head 54 based on the printing pattern to print it on the tablet T. The tablet T, to which the printing is to be done, is, for example, a drinkable size with a diameter of 5 mm to 15 mm. Furthermore, the code generation unit 44 can be implemented, for example, by one or both of hardware and software.

[0092] Here, in the first printing apparatus 20, the control unit 43, based on the detection information sent from the detection unit 22 (i.e., the timing of detecting the tablet T on the conveyor belt 21a), obtains the position of the tablet T in the conveying direction A1 on the conveyor belt 21a, and based on the position information indicating the position of the tablet T in the conveying direction A1, sets the first shooting timing of the first shooting unit 23, the printing start timing of the inkjet head 24, and the second shooting timing of the second shooting unit 25, generates timing information indicating these timings, and stores it in the storage unit 42. The printing start timing is the timing when printing begins on the tablet T that has reached the printing position directly below the inkjet head 24. This process is also the same in the second printing apparatus 50. Furthermore, the control unit 43 can obtain information such as the amount of movement (rotation) or speed of the conveyor belt 21a based on the detection information sent from the position detector 21e.

[0093] Furthermore, in the first printing apparatus 20, the control unit 43 sets whether the tablet T, for which the result data has been obtained, can be printed as printing capability information based on information regarding whether the tablet T is damaged or has foreign matter attached, sent from the image processing unit 41 (the information is based on the first image). Then, the control unit 43 sets the printing conditions as printing condition information for the tablet T that has been set as printable. At this time, the control unit 43 sets the printing conditions for the tablet T for which the position information has been obtained based on the position information of the tablet T in the X, Y, and θ directions sent from the image processing unit 41 (the information is based on the first image).

[0094] For example, the control unit 43 converts the QR code B1 generated by the code generation unit 44 into a printing pattern (e.g., grid data), and sets printing conditions for controlling the inkjet head 54 based on the printing pattern. Specifically, the control unit 43 determines the range of nozzles 24a used in printing the tablet T in the inkjet head 24, i.e., the nozzle range used, based on the position information of the tablet T in the Y direction or the printing pattern, and sets printing conditions including the nozzle range used or the printing start time, etc. Furthermore, when the tablet T has a directional shape, the control unit 43 sets printing conditions corresponding to the position of the tablet T in the θ direction based on the position information of the tablet T in the θ direction. As an example, the control unit 43 registers 180 printing patterns in the storage unit 42 that rotate the orientation of the printing pattern in 1-degree increments within a range of 0 to 179 degrees, and selects a printing pattern from these printing patterns whose angle corresponds to the position of the tablet T in the θ direction to set the printing conditions. This process is also the same in the second printing apparatus 50.

[0095] Furthermore, in the first printing apparatus 20, the control unit 43 determines whether the printed pattern (e.g., QR code B1) has been printed in a way that allows data to be read, based on image information of the printed pattern on the tablet T sent from the image processing unit 41 (the information is based on the second image), and sets the printing quality information (printing status check) for the tablet T. Moreover, the image of the printed pattern is a second image captured by the second imaging unit 25 (a printing inspection camera located further downstream of the inkjet head 54). The printing quality is determined based on the second image. This process is also performed in the second printing apparatus 50.

[0096] Specifically, the control unit 43 determines whether the QR code B1 printed on the tablet T in the second image can be read, and whether the read data (information) matches the batch number used as the original data. If the QR code B1 printed on the tablet T can be read, and the read data matches the batch number, the control unit 43 determines that the printing result of the QR code B1 is correct. On the other hand, if the QR code B1 printed on the tablet T cannot be read, or if the read data does not match the batch number, the control unit 43 determines that the printing result of the QR code B1 is incorrect.

[0097] Furthermore, the control unit 43 uses image processing to determine whether there are defects such as stains (e.g., black spots) in areas outside the area where the QR code B1 is printed. Moreover, since the area of ​​the QR code B1 can be determined based on the multiple positioning marks B1a, B1b, and B1c contained in the QR code B1, it is only necessary to check for stains in areas outside the determined area of ​​the QR code B1.

[0098] Then, if the control unit 43 determines that the printing result of QR code B1 is without problems and there are no defects such as stains in areas other than QR code B1, the printing result of tablet T is good (qualified). On the other hand, if the control unit 43 determines that the printing result of QR code B1 is problematic or there are defects such as stains in areas other than QR code B1, the printing result of tablet T is poor (unqualified). Tablets T judged to have poor printing results are discharged by the defective product collection unit 32 (defective product discharge device).

[0099] Furthermore, the control unit 43 appropriately stores various information (e.g., tablet T's location information, timing information, printing availability information, printing condition information, printing quality information, etc.) in the storage unit 42. When the tablet T is collected by the recycling device 30, for example, at a point when it falls off at the downstream end in the conveying direction A2 of the conveying unit 51 and a predetermined time (e.g., several seconds) has elapsed, the various information is deleted from the storage unit 42. If this information is needed in subsequent processes, it can be retained without deleting the information for each tablet T, or stored in a storage medium (external memory) outside the device. When storing the various information for each tablet T, it can also be stored in association with the information, manufacturing date, or batch number, etc., allowing for tracing back to cases of defective products after printing the tablet T to investigate the cause.

[0100] (Printing process)

[0101] Next, refer to Figure 5 The printing process performed by the tablet printing apparatus 1 will be described below. The printing process also includes an inspection process. Furthermore, various information, such as data required for printing or inspection, is pre-stored in the storage unit 42.

[0102] like Figure 5 As shown, in step S1, when a large number of tablets T intended for printing are fed into the hopper 11 of the supply device 10, the tablets T are sequentially fed from the hopper 11 to the arranging feeder 12, and moved in a row by the arranging feeder 12. The tablets T moving in a row are sequentially fed to the conveyor belt 21a of the first printing device 20 via the transfer feeder 13. The conveyor belt 21a rotates in the conveying direction A1 by the rotation of the drive pulley 21b based on the motor 21d and each driven pulley 21c. The tablets T supplied to the conveyor belt 21a at random intervals are arranged in a row on the conveyor belt 21a and conveyed away at a predetermined conveying speed.

[0103] In step S2, the detection unit 22 detects the tablet T on the conveyor belt 21a. Specifically, the detection unit 22 detects when the tablet T on the conveyor belt 21a reaches a detection position directly below the detection unit 22 (e.g., the position illuminated by a laser beam). Based on the timing of the detection of the tablet T, the position of the tablet T on the conveyor belt 21a in the conveying direction A1 is identified by the control unit 43. Furthermore, the control unit 43 generates position information indicating the position of the tablet T in the conveying direction A1 and stores it in the storage unit 42.

[0104] In step S3, the first imaging unit 23 captures an image of the tablet T on the conveyor belt 21a. Specifically, the first imaging unit 23 captures an image of the tablet T on the conveyor belt 21a at a first shooting moment when it reaches a shooting position directly below the first imaging unit 23, and the first image obtained by capturing the image using the first imaging unit 23 is sent to the control device 40. The first image is processed by the image processing unit 41 of the control device 40. Specifically, the image processing unit 41 processes the first image, generates information based on the first image regarding whether the tablet T is damaged or has foreign matter attached, and the position information of the tablet T in the X, Y, and θ directions, and stores this information in the storage unit 42.

[0105] In step S4, based on information regarding whether tablet T is damaged or has foreign matter attached, the control unit 43 determines whether printing can be performed on the target tablet T. If it is determined that printing can be performed on the target tablet T (Yes in step S4), the process proceeds to step S5. Furthermore, based on information such as the position of tablet T in the X, Y, and θ directions, or the printed pattern, printing conditions, including the nozzle range used for the tablet T (printable tablet T) and the printing start time, are set in the storage unit 42. Based on the printing start time (the time when printing begins on tablet T), the ink ejection time (the time when ink is ejected from tablet T) is determined. On the other hand, if it is determined that printing cannot be performed on the target tablet T (No in step S4), the process proceeds to step S9, restricting actions related to printing or inspecting the target tablet T. Furthermore, the printing capability information for tablet T is appropriately stored in the storage unit 42. Furthermore, the so-called "restriction" on actions related to printing or inspection means, at least, not to perform any processing related to the printing and inspection of the tablet T as the object.

[0106] In step S5, printing is performed by the inkjet head 24 based on the printing conditions. That is, the inkjet head 24 is controlled by the control unit 43 to print a predetermined pattern (e.g., QR code B1) onto the printable tablet T on the conveyor belt 21a. Specifically, printing is performed by the inkjet head 24 based on the printing start timing when the printable tablet T on the conveyor belt 21a below the first imaging unit 23 reaches the printing position directly below the inkjet head 24. In the inkjet head 24, ink is appropriately ejected from each nozzle 24a to print, for example, a QR code B1, on the printing surface, which is the upper surface of the tablet T.

[0107] In step S6, the second imaging unit 25 captures a picture of the printed tablet T on the conveyor belt 21a. Specifically, the second imaging unit 25 captures a picture of the printed tablet T on the conveyor belt 21a at a second shooting moment when it reaches a shooting position directly below the second imaging unit 25, and the second image obtained by capturing the picture using the second imaging unit 25 is sent to the control device 40. The second image is processed by the image processing unit 41 of the control device 40. Specifically, the image processing unit 41 processes the second image to generate image information of the printed pattern on the tablet T, and stores it in the storage unit 42. The image information includes, for example, information containing the brightness value (pixel value) of each pixel.

[0108] Furthermore, in processing the second image, in addition to obtaining image information of the printed pattern, the image processing unit 41 may also obtain, as needed, the printing position, shape, and size of the printed pattern printed on the tablet T. For example, the image processing unit 41 processes the second image sent from the second imaging unit 25 to generate information indicating the printing position, shape, and size of the printed pattern that has been printed on the tablet T, and stores it in the storage unit 42.

[0109] In step S7, based on the image information of the printed pattern on tablet T, the control unit 43 performs a printing status check (whether the printing result is qualified or not). Specifically, it determines whether the QR code B1 printed on tablet T in the second image can be read, and whether the read data (information) matches the batch number used as the original data. Furthermore, it determines whether there are any defects such as stains (e.g., black spots) in the area outside the area where the QR code B1 is printed.

[0110] If the QR code B1 printed on tablet T can be read and the read data matches the batch number, the printing result of QR code B1 is determined to be without problems. On the other hand, if the QR code B1 printed on tablet T cannot be read, or the read data does not match the batch number, the printing result of QR code B1 is determined to be problematic. Furthermore, if the printing result of QR code B1 is determined to be without problems and there are no stains or other defects in areas other than QR code B1, the printing result of tablet T is determined to be good (qualified) (Yes in step S7), and the process proceeds to step S8. On the other hand, if the control unit 43 determines that the printing result of QR code B1 is problematic, or there are stains or other defects in areas other than QR code B1, the printing result of tablet T is determined to be poor (unqualified) (No in step S7), and the process proceeds to step S9.

[0111] In step S8, the processes of steps S2 to S7 are repeated in the second printing device 50. The tablet T printed by the first printing device 20 is reversed and handed over to the lower second printing device 50, where the processes of steps S2 to S7 are performed. Thus, double-sided printing of the tablet T is also possible, but at least the QR code B1 is printed on one side of the tablet T. Furthermore, the conveyor belt 51a rotates in the conveying direction A2 by the rotation of the drive pulley 51b based on the motor 51d and each driven pulley 51c. Therefore, the tablets T handed over to the conveyor belt 51a are arranged in a row on the conveyor belt 51a and conveyed away at a predetermined conveying speed.

[0112] In step S9, the tablets T on the conveyor belt 51a of the second printing device 50 are recovered by the recycling device 30. Specifically, when a reusable tablet T reaches the reusable product recycling section 31 as the conveyor belt 51a moves, gas is blown onto the tablet T from above by the spray nozzle 31a, causing the tablet T to fall from the conveyor belt 51a and be collected in the recycling bin 31b. Similarly, when a defective tablet T reaches the defective product recycling section 32 as the conveyor belt 51a moves, gas is blown onto the tablet T from above by the spray nozzle 32a, causing the tablet T to fall from the conveyor belt 51a and be collected in the recycling bin 32b. Furthermore, when a good tablet T reaches a position near the end of each driven pulley 51c on the conveyor belt 51a, no suction action is applied to the tablet T; gas is blown onto the tablet T from above by the spray nozzle 33a, causing the tablet T to fall from the conveyor belt 51a and be collected in the recycling bin 33b. Controls related to the blowing of this gas, such as information on the position of tablet T, whether printing is possible, and whether printing is good or bad (results of printing status checks), are performed by the control unit 43.

[0113] In step S10, the control unit 43 determines whether printing has ended. For example, it counts the number of printed tablets T, and determines that printing has ended when the number reaches a predetermined production number. If printing is determined to be finished (yes in step S10), the process ends. On the other hand, if printing is determined not to be finished (no in step S10), the process returns to step S1. Furthermore, the determination of printing completion can also be based on the user's input operation on the input device 40a, for example, if the user presses the printing end button.

[0114] This printing process determines the printing quality of QR code B1 by checking if the data read from it matches the original data. This prevents situations where tablet T is judged as defective and rejected even if the stains on it are only minor enough to read QR code B1 or if the printing has peeled off. Therefore, the inspection accuracy of tablets T with printed information can be improved.

[0115] Furthermore, in the printing and inspection of QR code B1, the following situation is also considered: depending on the location or extent of printing defects, ink adhesion, or stains, even if the product is judged as good in pattern matching, the data read may differ from the original data. However, the first embodiment can prevent such misjudgment and improve the inspection accuracy of tablets T with information printed on them.

[0116] In addition, by determining whether the data read from the QR code B1 is consistent with the original data and thus determining the quality of the QR code B1 printing on tablet T, the inspection accuracy of tablet T with printed information can be improved.

[0117] Furthermore, when the information printed on tablet T, such as production information like batch numbers, is variable, it can be difficult to prepare templates for pattern matching. Typically, in pattern matching, a good tablet T with the printed pattern is prepared, and an image of the good tablet T is photographed and stored as a template. Then, the position where the image of the tablet T to be inspected most closely matches the template is searched. At the most consistent position, the image of the tablet T is compared with the template, and for each pixel, it is determined whether the difference in density is above a predetermined threshold, and pixels that are above the threshold are extracted. The printing quality is determined based on whether the size of the group of extracted pixels converges within a predetermined threshold. Moreover, to achieve the required inspection accuracy, the user sometimes adjusts the template. Therefore, when the information printed on tablet T is variable, such as production information, it is impossible to prepare templates in advance, or this increases the user's burden related to template generation and reduces production efficiency. On the other hand, with the first embodiment, a template for the QR code B1 does not need to be prepared. Therefore, compared to the case where determination is made using pattern matching, easier processing can be achieved.

[0118] As explained above, according to the first embodiment, the tablet printing apparatus 1 includes: a printing head (e.g., inkjet head 24, inkjet head 54) for printing on a tablet T; a control device 40 for controlling the printing head; and an imaging device (e.g., second imaging unit 25, second imaging unit 55) for imaging the tablet T printed by the printing head. The control device 40 controls the printing head to print a QR code B1 generated based on the original data and determines whether the data read from the QR code B1 contained in the image (e.g., a second image) obtained by the imaging device is consistent with the original data. This prevents the situation where the tablet T is judged as defective even though the stains on it are only to the extent that the QR code B1 can be read. Therefore, the inspection accuracy of tablet T with information printed on it can be improved. Furthermore, in the printing and inspection of the QR code B1, the situation where the tablet T is judged as good even though the read data has changed from the original data, depending on the location or extent of printing defects, ink adhesion, or stains, can be prevented. Therefore, the inspection accuracy of tablets T with printed information can be improved.

[0119] <Second Implementation>

[0120] Reference Figure 6 The second embodiment will now be described. In the second embodiment, the differences from the first embodiment will be explained.

[0121] like Figure 6As shown, in the second embodiment, the control unit 43 combines the QR code B1 with the character (image of the character) C1 to convert it into a printing pattern (e.g., raster data), and controls the inkjet head 54 based on the printing pattern to print on the tablet T. The character C1 can be, for example, the name of a pharmaceutical product, the content of the active ingredient, the manufacturer's name, the manufacturer's logo (a patterned or decorative character or string), or a string composed of these. This data of the character C1 (character data) is, for example, pre-stored in the storage unit 42. Therefore, the control unit 43 reads the character data from the storage unit 42 and combines the character C1 based on the character data with the QR code B1 generated by the code generation unit 44 to convert it into a printing pattern.

[0122] During the inspection process, the control unit 43 determines whether the QR code B1 printed on the tablet T in the second image can be read, and whether the read data (information) matches the batch number used as the original data (readout check). If the QR code B1 printed on the tablet T can be read, and the read data matches the batch number, the control unit 43 determines that the printing result of the QR code B1 is without problems. On the other hand, if the QR code B1 printed on the tablet T cannot be read, or if the read data does not match the batch number, the printing result of the QR code B1 is determined to be problematic. This type of inspection using data reading is called "readout check".

[0123] In addition, the control unit 43 checks the area outside the area where the QR code B1 is printed, i.e., the area outside the QR code B1, to see if the printing quality of characters C1 and other characters is good and if there are any stains. Furthermore, since the area of ​​the QR code B1 can be determined based on the multiple positioning marks B1a, B1b, and B1c contained in the QR code B1, the determined area of ​​the QR code B1 can be covered up and pattern matching can be performed to check the printing quality of characters C1 and other characters and if there are any stains. This kind of inspection using pattern matching is called "pattern matching inspection".

[0124] In pattern matching inspection, the control unit 43, for example, registers the printed pattern of the character C1, etc., for inspection in the storage unit 42, and compares the printed pattern of the character C1, etc., for inspection with the printed pattern of the character C1, etc., on the actual printed tablet T (the printed pattern of the character C1, etc., printed on tablet T). If the printed pattern of the character C1, etc., for inspection matches the printed pattern of the character C1, etc., printed on tablet T, it is determined that the printing of the character C1, etc., is good and there are no defects such as stains. On the other hand, if the printed pattern of the character C1, etc., for inspection does not match the printed pattern of the character C1, etc., printed on tablet T, it is determined that the printing of the character C1, etc., is poor or there are defects such as stains.

[0125] If the control unit 43 determines that the printing result of the QR code B1 is without problems, the printing of characters C1 is also good, and there are no stains or other defects, then the tablet's printing result is deemed good (acceptable). On the other hand, if the control unit 43 determines that the printing result of the QR code B1 is problematic, the printing of characters C1 is poor, or there are stains or other defects in areas other than the QR code B1, then the tablet T's printing result is deemed poor (unacceptable). Tablets T that are determined to have poor printing results are discharged by the defective product collection unit 32 (defective product discharge device).

[0126] In the case of tablets T of a permissible size, the printable area is small, thus the size of the QR code B1 is also small, making ink adhesion or printing fading less noticeable. Therefore, by judging the printing quality based on whether the data read from the QR code B1 matches the original data, the situation where minor defects are excessively rejected as defective products, thus reducing the yield, can be prevented.

[0127] Furthermore, characters such as C1, which are visual data for doctors, pharmacists, or patients, are easily highlighted when there are stains or printing defects, and this can lead to misreading. The second embodiment, by using pattern matching to check characters such as C1, allows for rigorous inspection of visually perceived information.

[0128] As explained above, the same effects as the first embodiment can be achieved through the second embodiment. Furthermore, by performing a readout check on the QR code B1 printed on the tablet T and a pattern matching check on the characters C1 printed on the tablet T, the inspection accuracy of the tablet T with printed information can be improved while simultaneously increasing the yield rate.

[0129] <Other Implementation Methods>

[0130] In the above description, the tablet printing apparatus 1 (tablet printing method) of the embodiment is used to print tablet T. This can also be described as using the tablet printing apparatus 1 (tablet printing method) of the embodiment to print tablet T to manufacture a printed tablet T. That is, the tablet printing apparatus 1 can be described as a tablet manufacturing apparatus, and the tablet printing method can be described as a tablet manufacturing method.

[0131] For example, the control device 40 may include software for generating the QR code B1, or it may utilize a generation service via the Internet. Alternatively, the control device 40 may pre-store the QR code B1.

[0132] The QR code B1 is generated based on a batch number, which is one example of production information, but it is not limited to this. Production information may include, for example, the name of the manufacturing plant or the date and time of production, the identification number of the tablet printing device 1, the expiration date of the tablet T, etc., and multiple such information may be selected. Furthermore, the raw data on which the QR code B1 is generated may also include the drug name or manufacturer name, etc. Additionally, the raw data may include a Uniform Resource Locator (URL) that allows access to this information.

[0133] Furthermore, if the original data changes midway through the printing process of the tablet printing apparatus 1, the code generation unit 44 can regenerate the code and continue printing based on this code. At this time, if the original data is changed, tablet supply can be paused, and unprinted tablets T located on conveyor belts 21a and 51a can be recycled to the reuse collection unit 31. Additionally, maintenance of the inkjet heads 24 and 54 can be performed when code regeneration is required.

[0134] In addition, the description states that for QR code B1, the printing quality is judged based on whether the data read from QR code B1 is consistent with the original data. However, it can also be further determined whether the position of QR code B1 is printed within the specified area on tablet T.

[0135] Alternatively, for QR code B1, the printing quality can be determined by whether the data read from QR code B1 matches the original data, and pattern matching can also be checked. In this case, the product is considered good as long as it passes both checks.

[0136] Furthermore, while the description mentions printing the QR code B1 on one side of tablet T, it is also possible to print the QR code B1 on both sides of tablet T. Additionally, the same printing pattern can be used on both sides of tablet T; for example, the QR code B1 can be printed on the surface, and information such as the character C1 can be printed on the back. Furthermore, in tablets with dividing lines on one side, the character C1 can be printed on the surface with the dividing lines, and the QR code B1 can be printed on the back where the dividing lines are not formed.

[0137] Furthermore, the description mentions printing a QR code B1 on one side of the tablet T, but it is not limited to QR code B1; barcodes (e.g., code (CODE) 39, NW-7) or three-dimensional codes formed using color printing may also be printed. That is, as codes, there are, for example, QR code B1, barcodes, three-dimensional codes, etc. These codes are generated, for example, by the code generation unit 44.

[0138] Furthermore, the description illustrates the conveying of tablet T in one column, but it is not limited to this. The number of columns can be two or more, and there is no particular limitation. The number of conveyor belts 21a (51a) can also be two or more, and there is no particular limitation. In addition, the number of inkjet heads 24 (54) can also be two or more, and there is no particular limitation.

[0139] Furthermore, in the above description, the inkjet head 24 (54) is exemplified as a printhead with nozzles 24a arranged in a row, but it is not limited to this. For example, printheads with nozzles 24a arranged in multiple rows can also be used. In addition, multiple inkjet heads 24 (54) can be arranged in a direction orthogonal to the transport direction A1 in the horizontal plane.

[0140] In addition, the description illustrates that the inkjet head 24 (54) is configured such that the direction in which the nozzles 24a are arranged is orthogonal to the transport direction A1 in the horizontal plane, but it is not limited to this. For example, the direction in which the nozzles 24a are arranged may be configured such that the direction in which the nozzles 24a are arranged is obliquely intersecting the transport direction A1 (A2) in the horizontal plane.

[0141] Furthermore, in the above description, tablets T are supplied to the conveyor belt 21a (51a) randomly rather than at fixed intervals, but this is not a limitation; they may also be supplied at fixed intervals. Additionally, in the above description, tablets T are drawn and held by suction holes 21g formed on the conveyor belt 21a (51a), but this is not a limitation; they may also be contained and held in a pocket or the like for transport, or they may be held on the conveyor belt 21a (51a) by their own weight for transport.

[0142] Here, the tablet T may include tablets used for pharmaceutical, dietary, cleaning, industrial, or aromatic purposes. Furthermore, the tablet T may be a bare tablet (uncoated), sugar-coated tablet, film-coated tablet, enteric-coated tablet, gelatin-coated tablet, multilayer tablet, cored tablet, etc., and various capsules such as hard capsules or soft capsules may also be included in the tablet T. Furthermore, the tablet T may have various shapes such as disc-shaped, lens-shaped, triangular, or elliptical. Additionally, when the tablet T to be printed is for pharmaceutical or dietary use, edible ink is suitable as the ink used. As the edible ink, any one of synthetic pigment ink, natural pigment ink, dye ink, or pigment ink can be used.

[0143] The foregoing has described several embodiments of the present invention, but these embodiments are merely illustrative and not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, modifications, and combinations can be made without departing from the spirit of the invention. These embodiments or variations thereof are included within the scope or spirit of the invention, and are included within the scope of the invention as described in the claims and its equivalents.

Claims

1. A tablet printing apparatus, comprising: The printhead prints onto the tablet; A control device controls the printing head; as well as The imaging device photographs the tablet that has been printed using the printhead. The control device controls the printing head to print a positioning mark, a QR code generated based on the original data, and characters based on character data printed on the outside of the QR code. The control device also performs: The area where the QR code is printed is determined based on the positioning markers contained in the image obtained using the imaging device. Only determine whether the data read from the QR code within the area containing the printed QR code is consistent with the original data. For areas other than those printed with the QR code, pattern matching is used to determine whether the characters printed on the tablet match the character data and whether there are any stains.

2. The tablet printing apparatus according to claim 1, wherein, The control device has a code generation unit for generating the QR code.

3. The tablet printing apparatus according to claim 1, wherein, The raw data contains production information related to the tablets.

4. A tablet printing method, comprising: The control device controls the print head that prints on the tablet to print including positioning marks, a QR code generated based on raw data, and characters based on character data printed on the outside of the QR code; as well as Based on the positioning markers contained in the image obtained using the imaging device, the area where the QR code is printed is determined, and the imaging device photographs the tablet that has been printed using the printing head. Only determine whether the data read from the QR code within the identified area printed with the QR code is consistent with the original data. For areas other than those printed with the QR code, pattern matching is used to determine whether the characters printed on the tablet match the character data and whether there are any stains.

Images