TWI853651B - Tablet printing device and tablet printing method - Google Patents

Abstract

The present invention provides a tablet printing device and a tablet printing method, which can improve the inspection accuracy of tablets printed with information in the form of codes. The tablet printing device of the embodiment includes: a printing head for printing on the tablet; a control device (40) for controlling the printing head; and a photographing device for photographing the tablet printed by the printing head. The control device (40) controls the printing head to print a code generated based on original data and determines whether the data read from the code contained in the image obtained by the photographing device is consistent with the original data.

Description

Tablet printing device and tablet printing method

The embodiments of the present invention relate to a tablet printing device and a tablet printing method.

Conventionally, identification information such as characters was printed on tablets using an inkjet head. By printing identification information directly on tablets, the tablet identification information can be confirmed even after the tablets are taken out of packaging containers such as press-through pack (PTP) sheets.

However, for example, in tablets for oral administration, the amount of information that can be printed on the tablet is limited due to the small size of the tablet. In contrast, if the information to be printed is converted into a code, such as a two-dimensional code such as a Quick Response (QR) code (registered trademark), and the two-dimensional code is printed on the tablet, the amount of information that can be displayed on the tablet can be increased.

The tablet printed with such a two-dimensional code is usually photographed by a camera to determine whether the two-dimensional code printed on the tablet is good or not. As a method of determining whether the two-dimensional code is good or not, pattern matching can be performed, for example. Generally speaking, two-dimensional codes have an error correction function, so even if there is a slight loss of printing or stains, the information can be read.

However, when pattern matching is used for inspection, although there is no problem in reading the message from the QR code printed on the tablet, the tablet printed with the QR code is sometimes judged as defective and ejected, thereby reducing the yield rate. In addition, in the inspection using pattern matching, the following situation is considered: although the tablet printed with the QR code is judged as good, an error message is read from the QR code printed on the tablet in the QR code reader.

[Prior art literature] [Patent literature] [Patent literature 1] Japanese Patent Publication No. 2019-58220

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

[Technical means for solving the problem] The tablet printing device of the embodiment of the present invention includes: a printing head for printing on a tablet; a control device for controlling the printing head; and a photographing device for photographing 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 the data read from the code contained in the image obtained by the photographing device is consistent with the original data.

The tablet printing method of the embodiment of the present invention includes: a control device controls a printing head that prints on the tablet to print a code generated based on original data; and determines whether the data read from the code contained in the image obtained by using a shooting device is consistent with the original data, and the shooting device shoots the tablet printed by the printing head.

[Effect of the invention] Through the implementation of the present invention, the inspection accuracy of tablets with information printed in code can be improved.

<First Implementation Method> The first implementation method is described with reference to Figures 1 to 5.

(Configuration example of tablet printing device) As shown in FIG1 , the tablet printing device 1 of the first embodiment includes a supply device 10, a first printing device 20, a second printing device 50, a recovery device 30, and a control device 40.

The supply device 10 includes a hopper 11, an arrangement feeder 12, and a delivery feeder 13. The supply device 10 is positioned at one end side of the first printing device 20, and is configured to supply the sheet T as a printing object to the first printing device 20. The hopper 11 contains a large number of sheets T, and sequentially supplies the contained sheets T to the arrangement feeder 12. The arrangement feeder 12 arranges the supplied sheets T in a row, and conveys them in a conveying direction A1 (clockwise) toward the delivery feeder 13. As the arrangement feeder 12, for example, a belt conveyor mechanism or a vibration feeder can be used. The delivery feeder 13 sucks each tablet T arranged in a row on the arrangement feeder 12 from the upper side of the tablet T in sequence and holds each tablet T, and conveys each held tablet T in a row to the first printing device 20 and transfers it to the first printing device 20. As the delivery feeder 13, for example, a belt conveying mechanism can be used. The belt conveying mechanism of the delivery feeder 13 rotates in the conveying direction A2 (counterclockwise). The supply device 10 is electrically connected to the control device 40, and the driving of the supply device 10 is controlled by the control device 40.

The first printing device 20 includes a conveying unit 21, a detecting 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 printing head (printing unit), and the second imaging unit 25 is an example of an imaging device.

The conveying section 21 has a conveying belt 21a, a driving pulley 21b, a plurality of driven pulleys 21c, a motor 21d, a position detector 21e, and a suction chamber 21f. The conveying belt 21a is an endless belt and is mounted on the driving pulley 21b and each driven pulley 21c. The driving pulley 21b and each driven pulley 21c are rotatably arranged on the device body (not shown), and the driving pulley 21b is connected to the motor 21d. The motor 21d is electrically connected to the control device 40, and the driving of the motor 21d is controlled by the control device 40. The position detector 21e is a device such as an encoder and is installed on the motor 21d. The position detector 21e is electrically connected to the control device 40 and sends a detection signal to the control device 40. The conveying section 21 causes the conveying belt 21 a to move together with the driven pulleys 21 c by the rotation of the driving pulley 21 b by the motor 21 d, and conveys the tablets T on the conveying belt 21 a in the conveying direction A1 (clockwise direction).

As shown in FIG2 , a plurality of circular suction holes 21g are formed on the conveyor belt 21a. These suction holes 21g are through holes for adsorbing tablets T, and are arranged in a row along the conveying direction A1 to form a conveying path. Each suction hole 21g is connected to the suction chamber 21f via a suction path (not shown) formed in the suction chamber 21f (refer to FIG1 ), and can obtain a suction force through the suction chamber 21f. The pump is connected to the suction chamber 21f via a suction pipe (not shown), and the pressure in the suction chamber 21f is reduced by the operation of the pump. The suction pipe is connected to the approximate center of the side surface (the surface parallel to the conveying direction A1) of the suction chamber 21f. The pump is electrically connected to the control device 40, and the driving of the pump is controlled by the control device 40. When the pressure in the suction chamber 21f is reduced, the tablets T placed on the suction holes 21g of the conveyor belt 21a are sucked by the suction holes 21g and are held on the conveyor belt 21a.

The detection unit 22 is positioned downstream of the position where the supply device 10 is provided in the conveying direction A1, and is provided above the conveying path where the suction holes 21g are arranged. The detection unit 22 detects the tablet T (arrival of the tablet T) that has reached the detection position directly below the detection unit 22, that is, the position of the tablet T on the conveyor belt 21a in the conveying direction A1, by projecting and receiving light with laser light. As the detection unit 22, for example, a displacement sensor can be used. In addition, as the displacement sensor, various laser sensors such as a reflection type laser sensor can be used. The detection unit 22 is electrically connected to the control device 40, and sends a detection signal to the control device 40.

The first imaging unit 23 is positioned downstream of the position where the detection unit 22 is provided in the conveying direction A1, and is provided above the conveying path where the suction holes 21g are arranged. The first imaging unit 23 captures the tablet T at a first capturing timing when the tablet T reaches the capturing position directly below the first imaging unit 23 based on the position information of the tablet T in the conveying direction A1 detected by the detection unit 22, acquires a first image including the upper surface of the tablet T, and transmits the acquired first image to the control device 40. The first image is used to detect the position of the tablet T in the X direction, the Y direction, and the θ direction (see FIG. 2 ). As the first camera unit 23, various cameras having a camera element such as a charge coupled device (CCD) or a complementary metal oxide film semiconductor (CMOS) can be used. The first camera unit 23 is electrically connected to the control device 40, and the driving of the first camera unit 23 is controlled by the control device 40. Furthermore, lighting for shooting is also provided as needed.

Here, the positions of the tablet T in the X direction and the Y direction are, for example, positions of the XY coordinate system relative to the center (reference position) of the imaging area of the first imaging unit 23. In addition, the position in the θ direction is, for example, a position indicating the degree of rotation of the tablet T in the horizontal plane along the XY plane of the imaging area of the first imaging unit 23. The position in the θ direction is detected when the tablet T has a directional shape, such as when a dividing line is provided on the tablet T, or when the tablet T is formed into an ellipse, an oblong, a triangle, a quadrilateral, etc. Furthermore, the X direction and the Y direction are positions in the horizontal direction.

The inkjet head 24 is positioned downstream of the conveying direction A1 relative to the position where the first shooting unit 23 is provided, and is provided above the conveying path where the suction holes 21g are arranged. The inkjet head 24 has a plurality of (e.g., hundreds to thousands) nozzles 24a (refer to FIG. 2 ), and the direction in which the nozzles 24a are arranged in a row (nozzle row) is arranged to be orthogonal to the conveying direction A1 in a horizontal plane (an example of intersection). The inkjet head 24 ejects ink from each nozzle 24a individually through the action of the driving element of each nozzle 24a. As the inkjet head 24, a printing head of various inkjet methods having a driving element such as a piezoelectric element, a heating element, or a magnetostrictive element can be used. The inkjet head 24 is electrically connected to the control device 40 , and the driving of the inkjet head 24 is controlled by the control device 40 .

The second imaging unit 25 is positioned downstream of the position where the inkjet head 24 is provided in the conveying direction A1, and is provided above the conveying path where the suction holes 21g are arranged. The second imaging unit 25 takes pictures at a second shooting timing when the tablet T reaches the shooting position directly below the second imaging unit 25 based on the position information of the tablet T in the conveying direction A1 detected by the detection unit 22, and obtains a second image including the upper surface of the tablet T, and transmits the obtained second image to the control device 40. The second image can be used to check the printed pattern printed on the tablet T. As the second imaging unit 25, various cameras having an imaging element such as a CCD or a CMOS can be used, similarly to the first imaging unit 23. The second camera unit 25 is electrically connected to the control device 40, and the driving of the second camera unit 25 is controlled by the control device 40. Lighting for shooting is also provided as needed.

The drying section 27 is arranged at a position facing the conveyor belt 21a, for example, below the conveyor belt 21. The drying section 27 dries the ink of each tablet T applied on the conveyor belt 21a. As the drying section 27, various dryers such as a blower that dries using a gas such as air, a heater that dries using radiation heat, or a blower that dries using warm or hot air by using a combination of a gas and a heater can be used. The drying section 27 is electrically connected to the control device 40, and the driving of the drying section 27 is controlled by the control device 40.

Here, the first printing device 20 and the second printing device 50 are arranged so that the conveying section 21 and a part of the conveying section 51 overlap each other up and down, and the sheet T printed by the first printing device 20 on the upper side is handed over to the second printing device 50 on the lower side, thereby printing both sides of the sheet T. Usually, in order to smoothly hand over the sheet 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.

The second printing device 50 has the same structure as the first printing device 20. That is, the second printing device 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 conveying belt 51a, a driving pulley 51b, a plurality of driven pulleys 51c, a motor 51d, a position detector 51e, and a suction chamber 51f. The conveying unit 51 conveys the sheet T on the conveying belt 51a along a conveying direction A2 (counterclockwise direction). 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. In addition, the components constituting the second printing device 50 are basically the same as the components constituting the first printing device 20, so their description is omitted.

The recovery device 30 is positioned on the downstream side of the conveying direction A2 relative to the position where the drying section 57 is provided, and is provided below the conveying section 51. The recovery device 30 includes a reused product recovery section 31, a defective product recovery section 32, and a good product recovery section 33. The recovery device 30 recovers the tablets T as reused products through the reused product recovery section 31, recovers the tablets T as defective products through the defective product recovery section 32, and recovers the tablets T as good products through the good product recovery section 33. For example, the reused products are reusable tablets and are non-printed sheets without damage or foreign matter attached thereto. In addition, defective products are non-printed sheets with foreign matter attached or defective printed sheets (printed sheets) without damage and foreign matter attached, etc., and good products are good printed sheets (printed sheets) without damage and foreign matter attached. Furthermore, the arrangement order of the reusable product recovery unit 31, the defective product recovery unit 32, and the good product recovery unit 33 in the conveying direction A2 is not limited to the arrangement order shown in FIG. 1, and can also be changed appropriately. The recovery device 30 is electrically connected to the control device 40, and the drive of the recovery device 30 is controlled by the control device 40.

The reusable product recovery section 31 has a spray nozzle 31a and a recovery box 31b. In addition, the defective product recovery section 32 has a spray nozzle 32a and a recovery box 32b. The good product recovery section 33 has a spray nozzle 33a and a recovery box 33b. These spray nozzles 31a, 32a, 33a have basically the same structure, and the recovery boxes 31b, 32b, 33b also have basically the same structure. Therefore, as a representative, the spray nozzle 31a and the recovery box 31b are described.

The spray nozzle 31a and the recovery box 31b are arranged at positions facing each other across the conveying path where the suction holes of the conveyor belt 51a are arranged. The spray nozzle 31a is arranged in the suction chamber 51f, for example, to spray gas (for example, air) toward the conveyor belt 51a, so that the tablet T falls from the conveyor belt 51a. At this time, the gas sprayed from the spray nozzle 31a hits 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 arranged directly below the spray nozzle 31a and below the conveyor part 51. The recovery box 31b receives and stores the tablets T dropped from the conveyor belt 51a due to the gas ejected from the ejection nozzle 31a.

Here, the tablets T passing through the recycling product recovery section 31 and the defective product recovery section 32 are conveyed along with the movement of the conveyor belt 51a, and arrive at a position near the end of each driven pulley 51c side of the conveyor belt 51a. At the above position, the suction effect no longer acts on the tablets T, but the gas is blown toward the tablets T from above the tablets T 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 stores the tablets T dropped from the conveyor belt 51a due to the gas sprayed from the spray nozzle 33a.

The control device 40 controls each unit of the sheet printing device 1, such as the supply device 10 or the first printing device 20, the second printing device 50, the recovery device 30, etc., based on various messages and various programs. In addition, the control device 40 receives detection data (for example, detection signals) and the like sent from the position detector 21e or the detection unit 22 of the conveying unit 21, the position detector 51e or the detection unit 52 of the conveying unit 51, and receives image data and the like 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 realized by, for example, an electronic circuit such as an integrated circuit or a computer.

(Configuration example of control device) Next, the configuration example of the control device 40 is described with reference to FIG. 3 .

As shown in FIG3 , 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 by, for example, a switch, a touch screen, a keyboard, a mouse, etc. In addition, the output device 40b is implemented by, for example, a display, a lamp, a measuring instrument, etc.

The image processing unit 41 imports the first image captured by the first imaging unit 23 or the first imaging unit 53 and the second image captured by the second imaging unit 25 or the second imaging unit 55, and processes the images using a known image processing technique. For example, the image processing unit 41 processes the first image acquired from the first imaging unit 23 to obtain whether the tablet T is damaged or foreign matter is attached, and the position of the tablet T in the X direction, the Y direction, and the θ direction. In addition, the image processing unit 41 processes the second image acquired from the second imaging unit 25 to obtain image information of a printed pattern printed on the tablet T. The image processing unit 41 sends information on whether the tablet T is damaged or has foreign matter attached, information on the position of each tablet T in the X direction, the Y direction, and the θ direction, and image information on the print pattern printed on each tablet T to the control unit 43.

The storage unit 42 stores various programs or various messages. The storage unit 42 is implemented by, for example, semiconductor memory elements such as random access memory (RAM), flash memory, or storage devices such as hard disks and optical disks. The storage unit 42 stores production data (production information), printing data related to printing, conveying speed data, etc. The so-called production data refers to data that changes with the production (manufacturing) of the printed tablets T. As production data, for example, batch numbers can be listed. The production data can be generated based on the information input by the user using the input device 40a, or it can be automatically generated by the control unit 43.

The control unit 43 is, for example, a computer such as a central processing unit (CPU) or a microcontroller (MCU), a microprocessor (MPU), and controls each unit. The control unit 43 can be implemented, for example, by one or both of hardware and software. For example, the control unit 43 controls the supply device 10 or 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 messages or various programs stored in the storage unit 42. In addition, the control unit 43 receives detection signals, etc., respectively sent from the position detector 21e of the conveying unit 21 or the detection unit 22, and the position detector 51e of the conveying unit 51 or the detection unit 52.

The code generation unit 44 generates a two-dimensional code B1 as shown in FIG4 based on the batch number (an example of production data) as the original data. The two-dimensional code B1 includes a plurality of positioning marks (cut out symbols) B1a, B1b, and B1c. In the example of FIG4, only the two-dimensional code B1 is printed on the tablet T. Furthermore, the control unit 43 converts the two-dimensional code B1 generated by the code generation unit 44 into a printing pattern (for example, raster data), and controls the inkjet head 54 based on the printing pattern to print on the tablet T. The tablet T to be printed is, for example, of an edible 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.

Here, the control unit 43 in the first printing device 20 obtains the position of the sheet T on the conveying belt 21a in the conveying direction A1 based on the detection information sent from the detection unit 22, that is, the timing of detecting the sheet T on the conveying belt 21a, and sets the first imaging timing of the first imaging unit 23, the printing start timing of the inkjet head 24, and the second imaging timing of the second imaging unit 25 based on the position information indicating the position of the sheet T in the conveying direction A1, and generates timing information indicating these timings and stores them in the storage unit 42. The so-called printing start timing is the timing of starting printing for the sheet T that has reached the printing position directly below the inkjet head 24. This processing is also the same in the second printing device 50. Furthermore, the control unit 43 can obtain information such as the movement amount (rotation amount) and speed of the conveyor belt 21a based on the detection information sent from the position detector 21e.

In addition, the control unit 43 sets whether the tablet T having the result data obtained can be printed as a print permission message in the first printing device 20 based on the information (the information is based on the first image) on whether the tablet T is damaged or has foreign matter attached, which is sent from the image processing unit 41. Then, the control unit 43 sets the printing conditions as the print condition message for the tablet T set to be printable. At this time, the control unit 43 sets the printing conditions for the tablet T having the position information, based on the position information (the information is based on the first image) of the tablet T in the X direction, the Y direction, and the θ direction sent from the image processing unit 41.

For example, the control unit 43 converts the two-dimensional 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 target sheet T in the inkjet head 24, that is, the use nozzle range, based on the position information of the sheet T in the Y direction or the printing pattern, and sets printing conditions including the use nozzle range or the printing start timing. Furthermore, when the sheet T is a directional shape, the control unit 43 sets the printing conditions corresponding to the position of the sheet T in the θ direction based on the position information of the sheet T in the θ direction. As an example, the control unit 43 registers 180 printing patterns in which the orientation of the printing pattern is rotated in units of 1 degree within a range of 0 to 179 degrees in the storage unit 42, and selects a printing pattern having an angle that matches the position of the tablet T in the θ direction from these printing patterns to set printing conditions. This processing is also the same in the second printing device 50.

In addition, the control unit 43 determines whether the printed pattern (for example, the two-dimensional code B1) is printed so that data can be read based on the image information of the printed pattern printed 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 inspection) of the tablet T. Furthermore, the image of the printed pattern is a second image captured by the second imaging unit 25 (a printing inspection camera arranged downstream of the inkjet head 54). The printing quality is determined based on the second image. This processing is also the same in the second printing device 50.

Specifically, the control unit 43 determines whether the two-dimensional code B1 printed on the tablet T in the second image can be read and whether the read data (message) is consistent with the lot number as the original data. If the two-dimensional code B1 printed on the tablet T can be read and the read data is consistent with the lot number, the control unit 43 determines that there is no problem with the printing result of the two-dimensional code B1. On the other hand, if the two-dimensional code B1 printed on the tablet T cannot be read or the read data is inconsistent with the lot number, it is determined that there is a problem with the printing result of the two-dimensional code B1.

In addition, the control unit 43 determines whether there is a defect such as stain (for example, black spot) in the area other than the area where the two-dimensional code B1 is printed, that is, the area outside the two-dimensional code B1, by image processing. Furthermore, since the area of the two-dimensional code B1 can be determined based on the multiple positioning marks B1a, B1b, and B1c included in the two-dimensional code B1, it is sufficient to check whether there is stain or the like in the area other than the determined area of the two-dimensional code B1.

Then, if it is determined that there is no problem with the printing result of the two-dimensional code B1 and there is no defect such as stain in the area other than the two-dimensional code B1, the control unit 43 determines that the printing result of the tablet T is good (qualified). On the other hand, if it is determined that there is a problem with the printing result of the two-dimensional code B1 or there is a defect such as stain in the area other than the two-dimensional code B1, the control unit 43 determines that the printing result of the tablet T is poor (unqualified). The tablet T determined to have a poor printing result is discharged by the defective product recovery unit 32 (defective discharge device).

Furthermore, the control unit 43 appropriately stores various information (e.g., information on the position of the tablet T, timing information, information on whether printing is possible, information on printing conditions, information on whether printing is good or not, etc.) in the storage unit 42, and when the target tablet T is collected by the collection device 30, for example, when the tablet T falls from the downstream end in the conveying direction A2 of the conveying unit 51 and a predetermined time (e.g., several seconds) has passed, the various information is deleted from the storage unit 42. However, if the information is required in a subsequent step, etc., the various information of each tablet T may be left without being deleted, or may be stored in a storage medium (external storage device) outside the device. When various information of each tablet T is stored, the information can also be stored in association with the manufacturing date or batch number, so that the printed tablet T can be traced back to the situation where defective products are produced after leaving the factory to investigate the cause.

(Printing step) Next, the printing step performed by the tablet printing device 1 will be described with reference to FIG. 5 . The printing step also includes an inspection step. Furthermore, various information such as data required for printing or inspection is pre-stored in the storage unit 42 .

As shown in FIG. 5 , in step S1, when a large amount of tablets T to be printed are put into the hopper 11 of the supply device 10, the tablets T are sequentially supplied from the hopper 11 to the arrangement feeder 12, and are arranged in a line by the arrangement feeder 12 and moved. The tablets T moving in a line are sequentially supplied to the conveyor belt 21a of the first printing device 20 through the transfer feeder 13. The conveyor belt 21a rotates in the conveying direction A1 by the rotation of the driving pulley 21b and each driven pulley 21c based on the motor 21d. The tablets T supplied to the conveyor belt 21a at random intervals are arranged in a line on the conveyor belt 21a and are conveyed at a predetermined conveying speed.

In step S2, the detection unit 22 detects the tablet T on the conveyor belt 21a. Specifically, the detection unit 22 detects that the tablet T on the conveyor belt 21a reaches the detection position (for example, the laser light irradiation position) directly below the detection unit 22, and 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 recognized by the control unit 43. Then, 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.

In step S3, the first photographing unit 23 photographs the tablet T on the conveyor belt 21a. Specifically, the first photographing unit 23 photographs the tablet T on the conveyor belt 21a at the first photographing timing when the tablet T reaches the photographing position directly below the first photographing unit 23, and transmits the first image obtained by the photographing by the first photographing unit 23 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 on whether the tablet T is damaged or foreign matter is attached, and position information of the tablet T in the X direction, Y direction, and θ direction based on the first image, and stores the information in the storage unit 42.

In step S4, the control unit 43 determines whether the target sheet T can be printed based on information about whether the sheet T is damaged or has foreign matter attached. If it is determined that the target sheet T can be printed (Yes in step S4), the process proceeds to step S5. Furthermore, based on information about the position of the sheet T in the X direction, Y direction, and θ direction or information about the printed pattern, printing conditions including the nozzle range to be used or the printing start timing for the sheet T set to be printable (printable sheet T) are set in the storage unit 42. Based on the printing start timing (the timing to start printing on the sheet T), the ejection timing for the sheet T (the timing to eject ink on the sheet T) is determined. On the other hand, when it is determined that the target tablet T is not to be printed (No in step S4), the process proceeds to step S9, and the operation related to printing or inspection of the target tablet T is restricted. Furthermore, the information on whether the tablet T can be printed is appropriately stored in the storage unit 42. Furthermore, the so-called "restriction" of the operation related to printing or inspection means at least not performing the operation related to printing and inspection of the target tablet T.

In step S5, the inkjet head 24 performs printing based on the printing conditions. That is, the inkjet head 24 is controlled by the control unit 43 to print a predetermined printing pattern (for example, a two-dimensional code B1) on the printable sheet T on the conveyor belt 21a. Specifically, when the printable sheet T on the conveyor belt 21a that has passed under the first imaging unit 23 reaches the printing position directly under the inkjet head 24, the inkjet head 24 performs printing based on the printing conditions. In the inkjet head 24, ink is appropriately ejected from each nozzle 24a, and a two-dimensional code B1, for example, is printed on the printed surface that is the upper surface of the sheet T.

In step S6, the second photographing unit 25 photographs the printed tablet T on the conveyor belt 21a. Specifically, the printed tablet T on the conveyor belt 21a is photographed by the second photographing unit 25 at the second photographing timing when the tablet T reaches the photographing position directly below the second photographing unit 25, and the second image obtained by the photographing by the second photographing 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, generates image information of the printed pattern printed on the tablet T, and stores it in the storage unit 42. Image information includes, for example, the brightness value (pixel value) of each pixel.

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

In step S7, the control unit 43 performs a printing status check (eligibility of the printing result) based on the image information of the printed pattern printed on the tablet T. Specifically, it is determined whether the two-dimensional code B1 printed on the tablet T in the second image can be read, and whether the read data (information) is consistent with the lot number as the original data. Furthermore, it is determined whether there is a defect such as stain (for example, black spots) in the area other than the area where the two-dimensional code B1 is printed, that is, the area outside the two-dimensional code B1.

If the two-dimensional code B1 printed on the tablet T can be read and the read data is consistent with the batch number, it is determined that the printing result of the two-dimensional code B1 has no problem. On the other hand, if the two-dimensional code B1 printed on the tablet T cannot be read or the read data is inconsistent with the batch number, it is determined that the printing result of the two-dimensional code B1 has a problem. Furthermore, if it is determined that the printing result of the two-dimensional code B1 has no problem and there is no defect such as stain in the area other than the two-dimensional code B1, it is determined that the printing result of the tablet T is good (qualified) (yes in step S7), and the processing enters step S8. On the other hand, if the control unit 43 determines that the printing result of the two-dimensional code B1 has a problem or there is a defect such as stain in the area other than the two-dimensional code B1, it determines that the printing result of the tablet T is poor (unqualified) (No in step S7), and the processing proceeds to step S9.

In step S8, the processing of steps S2 to S7 is repeated in the second printing device 50. The sheet T printed by the first printing device 20 is reversed and handed over to the second printing device 50 on the lower side, and the processing of steps S2 to S7 is performed in the second printing device 50. In this way, double-sided printing of the sheet T can also be achieved, but the two-dimensional code B1 is at least printed on one side of the sheet T. Furthermore, the conveyor belt 51a rotates in the conveying direction A2 by the rotation of the driving pulley 51b and each driven pulley 51c based on the motor 51d. Therefore, the sheet T handed over to the conveyor belt 51a is arranged in a row on the conveyor belt 51a and is conveyed at a prescribed conveying speed.

In step S9, the sheet T on the conveyor belt 51a of the second printing device 50 is recovered by the recovery device 30. Specifically, when the sheet T, which is a recyclable product, reaches the recyclable product recovery unit 31 as the conveyor belt 51a moves, gas is blown toward the sheet T from above the sheet T by the spray nozzle 31a, and the sheet T falls from the conveyor belt 51a and is received by the recovery box 31b. Similarly, when the sheet T, which is a defective product, reaches the defective product recovery unit 32 as the conveyor belt 51a moves, gas is blown toward the sheet T from above the sheet T by the spray nozzle 32a, and the sheet T falls from the conveyor belt 51a and is received by the recovery box 32b. When a good-quality sheet T reaches a position near the end of each driven pulley 51c in the conveyor belt 51a, the suction effect is not exerted on the sheet T, and gas is blown toward the sheet T from above the sheet T through the ejection nozzle 33a, and the sheet T falls from the conveyor belt 51a and is collected in the recovery box 33b. The control related to the blowing of gas is executed by the control unit 43 based on various messages such as the position message of the sheet T, the printing permission message, and the printing quality message (the result message of the printing state check).

In step S10, the control unit 43 determines whether printing has been completed. For example, the number of printed tablets T is counted, and when the number reaches a predetermined production number, it is determined that printing has been completed. When it is determined that printing has been completed (Yes in step S10), the process is completed. On the other hand, when it is determined that printing has not been completed (No in step S10), the process returns to step S1. In addition, the determination of the completion of printing can also be based on the user's input operation on the input device 40a, for example, based on the user pressing a print completion button, to determine that printing has been completed.

Through this printing step, the quality of printing is determined based on whether the data read from the two-dimensional code B1 is consistent with the original data. This can prevent the tablet T from being judged as defective and discharged even though the stain on the tablet T is to the extent that the two-dimensional code B1 can be read or the print is missing. Therefore, the inspection accuracy of the tablet T with information printed in the code can be improved.

In addition, in the printing and inspection of the two-dimensional code B1, the following situation is also considered: depending on the location or degree of the print falling off, ink or stain, although it is judged as a good product in the pattern matching, the read data has become different from the original data. However, through the first embodiment, such misjudgment can be prevented, and the inspection accuracy of the tablet T with information printed in the code can be improved.

In addition, by simply judging whether the data read from the two-dimensional code B1 is consistent with the original data and determining whether the printing quality of the two-dimensional code B1 on the tablet T is good or not, the inspection accuracy of the tablet T with information printed in the code can be improved.

In addition, when the information printed on the tablet T is a variable information such as production information such as a batch number, it is sometimes difficult to prepare a template for pattern matching. Usually, in pattern matching, a tablet T as a good product printed with a printed pattern is prepared, and an image of the good tablet T is stored as a template. Then, the position where the image of the tablet T to be inspected is most consistent with 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 greater than a predetermined threshold, and the pixels that are greater than the threshold are extracted. The quality of the printing is determined based on whether the size of the group of extracted pixels converges within a predetermined threshold. Furthermore, in order to achieve the required inspection accuracy, the user may need to adjust the template. Therefore, if the information printed on the tablet T is a variable information such as a production information, it is impossible to prepare a template in advance, or the burden on the user related to template generation increases, and the production efficiency decreases. On the other hand, according to the first embodiment, it is not necessary to prepare a template for the two-dimensional code B1. Therefore, compared with the case of making a judgment by pattern matching, it is possible to achieve easy processing.

As described above, according to the first embodiment, the sheet printing device 1 includes: a printing head (e.g., an inkjet head 24, an inkjet head 54) for printing on a sheet T; a control device 40 for controlling the printing head; and a photographing device (e.g., a second photographing unit 25, a second photographing unit 55) for photographing the sheet T printed by the printing head. The control device 40 controls the printing head to print a two-dimensional code B1 generated based on original data, and determines whether the data read from the two-dimensional code B1 contained in the image (e.g., the second image) obtained by the photographing device is consistent with the original data. Thus, it is possible to suppress the situation that the tablet T is judged as defective even though the stain on the tablet T is to the extent that the two-dimensional code B1 can be read. Therefore, the inspection accuracy of the tablet T on which the message is printed can be improved. In addition, in the printing and inspection of the two-dimensional code B1, it is possible to suppress the situation that the tablet T is judged as good even though the read data has become different from the original data depending on the location or degree of the print falling off, ink or stain. Therefore, the inspection accuracy of the tablet T on which the message is printed can be improved.

<Second Implementation Method> The second implementation method is described with reference to FIG. 6. In the second implementation method, the differences from the first implementation method are described.

As shown in FIG6 , the control unit 43 of the second embodiment combines the two-dimensional code B1 with the character (character image) C1 to convert it into a printing pattern (e.g., grid data), and controls the inkjet head 54 based on the printing pattern to print on the tablet T. As the character C1, for example, there are drug names, active ingredient content, manufacturer names, manufacturer name logos (patterned or decorated characters or character strings), etc., and there are also character strings composed of these. Such character C1 data (character data) is stored in advance in the storage unit 42, for example. Therefore, the control unit 43 reads the character data from the storage unit 42, combines the character C1 based on the character data with the two-dimensional code B1 generated by the code generation unit 44, and converts it into a printing pattern.

In the inspection step, the control unit 43 determines whether the two-dimensional code B1 printed on the tablet T in the second image can be read, and whether the read data (message) is consistent with the batch number as the original data (reading inspection). When the two-dimensional code B1 printed on the tablet T can be read and the read data is consistent with the batch number, the control unit 43 determines that there is no problem with the printing result of the two-dimensional code B1. On the other hand, when the two-dimensional code B1 printed on the tablet T cannot be read or the read data is inconsistent with the batch number, it is determined that there is a problem with the printing result of the two-dimensional code B1. This inspection using the reading of data is called "reading inspection".

In addition, the control unit 43 checks the quality of printing of the characters C1 and the like and the presence of stains, etc., in the area other than the area where the two-dimensional code B1 is printed, that is, the area outside the two-dimensional code B1. Furthermore, since the area of the two-dimensional code B1 can be determined based on the multiple positioning marks B1a, B1b, and B1c included in the two-dimensional code B1, the determined area of the two-dimensional code B1 can be masked and pattern matching can be performed to check the quality of printing of the characters C1 and the presence of stains, etc. This inspection using pattern matching is called "pattern matching inspection".

In the pattern matching check, the control unit 43, for example, registers the printed pattern of the characters C1 etc. for inspection in the storage unit 42, and compares the printed pattern of the characters C1 etc. for inspection with the printed pattern of the characters C1 etc. on the sheet T after actual printing (the printed pattern of the characters C1 etc. printed on the sheet T). When the printed pattern of the characters C1 etc. for inspection is consistent with the printed pattern of the characters C1 etc. printed on the sheet T, it is determined that the printing of the characters C1 etc. is good and there is no defect such as stain. On the other hand, when the printed pattern of the characters C1 etc. for inspection is inconsistent with the printed pattern of the characters C1 etc. printed on the sheet T, it is determined that the printing of the characters C1 etc. is poor or there is a defect such as stain.

When the control unit 43 determines that the printing result of the two-dimensional code B1 is fine, the printing of the characters C1 and the like is also good, and there is no defect such as stain, the printing result of the tablet is good (passed). On the other hand, when the control unit 43 determines that the printing result of the two-dimensional code B1 is problematic, the printing of the characters C1 and the like is poor, or there is a defect such as stain in the area other than the two-dimensional code B1, the printing result of the tablet T is poor (failed). The tablet T determined to have a poor printing result is discharged by the defective product recovery unit 32 (defective discharge device).

Here, in the case of a tablet T of a size that can be taken, the area that can be printed is small, so the size of the two-dimensional code B1 is also small, and ink adhesion or print fall-off is not easy to stand out. Therefore, by judging the quality of printing based on whether the data read from the two-dimensional code B1 is consistent with the original data, it is possible to prevent minor defects from being excessively treated as defective products and reducing the yield.

In addition, the character C1 and the like are data that are visually viewed by doctors, pharmacists, patients, etc., so stains or print failures are easily highlighted, and there is a possibility of misreading. According to the second embodiment, the character C1 and the like are checked by pattern matching, so that the visual information can be strictly checked.

As described above, the second embodiment can achieve the same effect as the first embodiment. In addition, by performing a read check on the two-dimensional code B1 printed on the tablet T and performing a pattern matching check on the character C1 printed on the tablet T, the inspection accuracy of the tablet T printed with information in the code can be improved while achieving an improvement in yield.

<Other embodiments> In the above description, the sheet T is printed using the sheet printing device 1 (sheet printing method) of the embodiment, which can also be said to be printed using the sheet printing device 1 (sheet printing method) of the embodiment to produce the printed sheet T. That is, the sheet printing device 1 can be said to be a sheet manufacturing device, and the sheet printing method can be said to be a sheet manufacturing method.

For example, the control device 40 may include software for generating the two-dimensional code B1, or may utilize a generation service via the Internet. In addition, the control device 40 may also store the two-dimensional code B1 in advance.

The two-dimensional code B1 is generated based on the batch number as an example of production information, but is not limited to this. The production information may be, for example, the name of the production 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 items may be selected from these information. In addition, the original data used as the basis for generating the two-dimensional code B1 may also include the name of the drug or the name of the manufacturer. In addition, the original data may also include a uniform resource locator (URL) that can access these information.

In addition, when the original data is changed in the middle of the printing step of the tablet printing device 1, the code generating unit 44 can regenerate the code and continue printing based on the code. At this time, if the original data is changed, the supply of tablets can be suspended, and the unprinted tablets T on the conveyor belt 21a and the conveyor belt 51a at this time point can be collected to the reusable product collection unit 31. In addition, the inkjet head 24 and the inkjet head 54 can also be maintained when the code needs to be regenerated.

In the above description, the printing quality of the two-dimensional code B1 is determined based on whether the data read from the two-dimensional code B1 is consistent with the original data. However, it is also possible to further determine whether the position of the two-dimensional code B1 is printed within a specified area on the tablet T.

In addition, the printing quality can be judged based on whether the data read from the two-dimensional code B1 is consistent with the original data, and the pattern matching inspection can also be performed. In the above case, it can be judged as a good product as long as both inspections are qualified.

In the above description, the two-dimensional code B1 is printed on one side of the sheet T, but the two-dimensional code B1 may be printed on both sides of the sheet T. In addition, the same printing pattern may be printed on both sides of the sheet T, and for example, the two-dimensional code B1 may be printed on the front side, and information such as characters C1 may be printed on the back side. In addition, in a dividing line sheet having a dividing line formed on one side, characters C1 may be printed on the front side having the dividing line formed, and the two-dimensional code B1 may be printed on the back side where the dividing line is not formed.

In the above description, it is described that the two-dimensional code B1 is printed on one side of the tablet T, but it is not limited to the two-dimensional code B1, and a barcode (for example, code (CODE) 39, NW-7) or a three-dimensional code formed by color printing may be printed. That is, as the code, there are, for example, the two-dimensional code B1, the barcode, the three-dimensional code, etc. These codes are generated by the code generation unit 44, for example.

In the above description, the example of conveying the sheets T in one row is shown, but the present invention is not limited thereto. The number of rows may be two or more, and there is no particular limitation. The number of conveyor belts 21a (51a) may be two or more, and there is no particular limitation. In addition, the number of inkjet heads 24 (54) may be two or more, and there is no particular limitation.

In the above description, a print head in which the nozzles 24a are arranged in a row is exemplified as the inkjet head 24 (54), but the present invention is not limited thereto, and for example, a print head in which the nozzles 24a are arranged in a plurality of rows may be used. In addition, a plurality of inkjet heads 24 (54) may be arranged in a direction perpendicular to the conveying direction A1 in a horizontal plane and used.

In addition, in the above description, the inkjet head 24 (54) is illustrated as being arranged so that the direction in which the nozzles 24a are arranged is orthogonal to the conveying direction A1 in the horizontal plane, but the present invention is not limited to this. For example, the inkjet head 24 (54) may be arranged so that the direction in which the nozzles 24a are arranged is obliquely intersecting with the conveying direction A1 (A2) in the horizontal plane.

In the above description, the tablets T are not supplied to the conveyor belt 21a (51a) at random but at regular intervals, but the present invention is not limited thereto and the tablets T may be supplied at regular intervals. In the above description, the tablets T are sucked and held by the suction holes 21g formed on the conveyor belt 21a (51a), but the present invention is not limited thereto and the tablets T may be held in a bag or the like for conveyance, or held on the conveyor belt 21a (51a) by its own weight for conveyance.

Here, the tablet T may include tablets used for medical purposes, dietary purposes, cleaning purposes, industrial purposes or aromatic purposes. In addition, as the tablet T, there are bare tablets (uncoated tablets) or sugar-coated tablets, film-coated tablets, enteric tablets, gelatin-coated tablets, multi-layer tablets, core tablets, etc., and various capsule tablets such as hard capsules or soft capsules may also be included in the tablet T. Furthermore, as the shape of the tablet T, there are various shapes such as disc or lens, triangle, ellipse, etc. In addition, when the tablet T as the printing object is for medical use or dietary use, the ink used is suitable for edible ink. As the edible ink, any one of synthetic pigment ink, natural pigment ink, dye ink, and pigment ink can be used.

Several embodiments of the present invention have been described above, but these embodiments are provided as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms and can be omitted, replaced, changed, and combined in various ways without departing from the subject matter of the invention. These embodiments or their variations are included in the scope or subject matter of the invention and are included in the invention described in the scope of the claims and their equivalents.

1: Tablet printing device 10: Supply device 11: Hopper 12: Arrangement feeder 13: Transfer feeder 20: First printing device 21, 51: Conveyor unit 21a, 51a: Conveyor belt 21b, 51b: Driving pulley 21c, 51c: Driven pulley 21d, 51d: Motor 21e, 51e: Position detector 21f, 51f: Suction chamber 21g: Suction hole 22, 52: Detection unit 23, 53: First shooting unit 24, 54: Inkjet head 24a: Nozzle 25, 55: Second shooting unit 27, 57: Drying unit 30: Recovery device 31: Recyclable product collection section 31a, 32a, 33a: Injection nozzle 31b, 32b, 33b: Collection box 32: Defective product collection section 33: Good product collection section 40: Control device 40a: Input device 40b: Output device 41: Image processing section 42: Storage section 43: Control section 44: Code generation section 50: Second printing device A1, A2: Conveying direction B1: Two-dimensional code B1a, B1b, B1c: Positioning mark C1: Character (image of character) S1, S2, S3, S4, S5, S6, S7, S8, S9, S10: Step T: Tablet X, Y, θ: Direction

FIG. 1 is a diagram showing an example of a schematic structure of a tablet printing device of the first embodiment. FIG. 2 is a diagram showing an example of a schematic structure of a printing device of the first embodiment. FIG. 3 is a diagram showing an example of a schematic structure of a control device of the first embodiment. FIG. 4 is a diagram for illustrating an example of a two-dimensional code of the first embodiment. FIG. 5 is a flowchart showing an example of a process of a printing step of the first embodiment. FIG. 6 is a diagram for illustrating an example of a two-dimensional code and a character string of the second embodiment.

40: Control device

40a: Input device

40b: Output device

41: Image processing department

42: Storage Department

43: Control Department

44: Code generation department

Claims (8)

A tablet printing device includes: a printing head for printing on a tablet; a control device for controlling the printing head; and a photographing device for photographing the tablet printed by the printing head, wherein the control device controls the printing head to print a code generated based on original data, controls the printing head to print characters based on character data in addition to the code, and determines whether the data read from the code contained in the image obtained by the photographing device is consistent with the original data. A tablet printing device as described in claim 1, wherein the control device has a code generating unit for generating the code. A tablet printing device as described in claim 1, wherein the original data includes production information related to the tablet. The tablet printing device as described in claim 1, wherein the control device uses pattern matching to determine whether the character printed on the tablet is consistent with the character data. The tablet printing device as described in claim 4, wherein the code is a two-dimensional code, and the control device determines the area to be determined by pattern matching based on the positioning mark contained in the two-dimensional code. The tablet printing device as described in claim 1, wherein the control device only determines whether the data read from the code is consistent with the original data, and determines whether the printing of the code on the tablet is good or not. The tablet printing device as described in claim 4, wherein the control device only determines whether the data read from the code is consistent with the original data, and determines whether the printing of the code on the tablet is good or not. A tablet printing method includes: a control device controls a printing head that prints on a tablet to print a code generated based on original data; controls the printing head to print characters based on character data in addition to the code; and determines whether data read from the code included in an image obtained by a photographing device is consistent with the original data, wherein the photographing device photographs the tablet printed by the printing head.

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