JP7397132B2 - Tablet printing device and tablet printing method - Google Patents

Description

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

Currently, in order to print various information such as identification information on tablets, tablet printing apparatuses are being developed that print using inkjet heads. This tablet printing apparatus uses a detection unit such as a sensor or a camera to detect a tablet to be printed. Foreign matter such as tablet powder or dust may adhere to the cover of the detection unit, and this foreign matter may cause the detection unit to erroneously detect the tablet, making it impossible to print on the tablet efficiently.

JP2019-58220A

The problem to be solved by the present invention is to provide a tablet printing device and a tablet printing method that can efficiently print on tablets.

A tablet printing device according to an embodiment of the present invention includes a detection unit that detects a tablet conveyed by a conveyor belt, an inkjet head that prints on the tablet detected by the detection unit, and a cover unit that covers the detection unit. and a blowing part that blows gas on the surface of the cover part on the conveying belt side in a direction that intersects horizontally with the conveying direction of the tablets in a plan view, and a control part that controls the blowing part. .

The tablet printing method according to the embodiment of the present invention includes: a detection unit detecting a tablet conveyed by a conveyor belt; an inkjet head printing on the tablet detected by the detection unit; the control unit blows gas against the surface of the cover unit that covers the detection unit on the conveyor belt side in a direction horizontally intersecting the conveyance direction of the tablets in plan view; and controlling.

According to the embodiments of the present invention, it is possible to efficiently print on tablets.

1 is a first diagram showing an example of a schematic configuration of a tablet printing device according to a first embodiment; FIG. FIG. 2 is a second diagram showing an example of a schematic configuration of the tablet printing device according to the first embodiment. FIG. 2 is a first diagram showing an example of a schematic configuration of a cover part and a blow device according to the first embodiment. FIG. 2 is a second diagram showing an example of a schematic configuration of a cover part and a blow device according to the first embodiment. FIG. 1 is a diagram showing an example of a schematic configuration of a control device according to a first embodiment. 2 is a flowchart showing the flow of processing example 1 according to the first embodiment. 7 is a flowchart showing the flow of processing example 2 according to the first embodiment. 7 is a flowchart showing the flow of processing example 3 according to the first embodiment. 12 is a flowchart showing the flow of processing example 4 according to the first embodiment. 12 is a flowchart showing the flow of processing example 5 according to the first embodiment. 12 is a flowchart showing the flow of processing example 6 according to the first embodiment. It is a figure showing an example of a schematic structure of a blowing device concerning a 2nd embodiment.

<First embodiment>
A first embodiment will be described with reference to FIGS. 1 to 11.

(Example of configuration of tablet printing device)
A configuration example of a tablet printing apparatus 1 according to a first embodiment will be described with reference to FIGS. 1 to 4.

As shown in FIGS. 1 and 2, the tablet printing apparatus 1 according to the first embodiment includes a supply section 10, a conveyance section 20, a sensor 30, a first imaging section 40, a printing section 50, It includes a second imaging section 60, a cover section 70, a blow device 80, a collection section 90, and a control device 100. The sensor 30, the first imaging section 40, and the second imaging section 60 each function as a detection section that detects the tablet T.

The supply section 10 has a hopper 11 and a chute 12. The supply section 10 is positioned at one end of the conveyance section 20 and is configured to be able to supply tablets T, which are objects to be printed, to the conveyance section 20 . The hopper 11 accommodates a large number of tablets T, and sequentially supplies the accommodated tablets T to the shooter 12. The shooter 12 arranges the tablets T supplied from the hopper 11 in a line and supplies them to the transport section 20. The supply unit 10 is electrically connected to the control device 100, and its driving is controlled by the control device 100.

The conveyance unit 20 includes a conveyance belt 21 , a driving pulley 22 , a plurality of driven pulleys 23 , a motor 24 , a position detector 25 , and a suction chamber 26 . The conveyor belt 21 is an endless belt, and is stretched around a drive pulley 22 and each driven pulley 23 . The drive pulley 22 and each driven pulley 23 are rotatably provided in the device main body (not shown), and the drive pulley 22 is connected to a motor 24. The motor 24 is electrically connected to the control device 100, and its driving is controlled by the control device 100. The position detector 25 is a device such as an encoder, and is attached to the motor 24. This position detector 25 is electrically connected to the control device 100 and transmits a detection signal to the control device 100. The conveyor unit 20 rotates the conveyor belt 21 together with each driven pulley 23 by the rotation of the driving pulley 22 by the motor 24, and conveys the tablets T on the conveyor belt 21 in the rotation direction of arrow H1 in FIG. 1, that is, in the conveyance direction H1. do.

A plurality of circular suction holes 21a (see FIG. 2) are formed in the conveyor belt 21. These suction holes 21a are through holes that suck the tablets T, and are arranged in a line along the conveyance direction H1 so as to form one conveyance path. Each suction hole 21a is connected to the suction chamber 26 through a suction path (not shown) formed in the suction chamber 26 (see FIG. 1), and it is possible to obtain suction force from the suction chamber 26. It has become. A pump is connected to the suction chamber 26 via a suction pipe (none of which is shown), and the pressure inside the suction chamber 26 is reduced by operation of the pump. The suction tube is connected to approximately the center of the side surface of the suction chamber 26 (a surface parallel to the transport direction H1). Further, the pump is electrically connected to the control device 100, and its driving is controlled by the control device 100. When the pressure inside the suction chamber 26 is reduced, the tablets T placed on each suction hole 21a of the conveyor belt 21 are sucked by the suction hole 21a and held on the conveyor belt 21.

The sensor 30 is located downstream of the position where the supply unit 10 is provided in the transport direction H1, and is provided above the transport belt 21. This sensor 30 detects the position of the tablet T on the conveyor belt 21 in the X direction (see FIG. 2), that is, the tablet T that has reached the detection position directly below the sensor 30 (arrival of the tablet T) by emitting and receiving laser light. do. As the sensor 30, for example, a displacement sensor, a proximity sensor, etc. are used. Further, as the displacement sensor, for example, various laser sensors such as a reflective laser sensor are used. The sensor 30 is electrically connected to the control device 100 and transmits a detection signal to the control device 100.

The first imaging unit 40 is located downstream in the transport direction H1 from the position where the sensor 30 is provided, and is provided above the transport belt 21. The first imaging unit 40 takes an image at a first imaging timing when the tablet T reaches an imaging position directly below the first imaging unit 40 based on the position information of the tablet T in the X direction detected by the sensor 30. is performed, a first image including the top surface of the tablet T is acquired, and the acquired first image is transmitted to the control device 100. The first image is used to detect the position of the tablet T in the X direction, Y direction, and θ direction (see Figure 2), and also to detect the presence or absence of cracks, chips, and dirt (for example, adhesion of foreign matter) on the tablet T. used for As the first imaging unit 40, various cameras having an imaging element such as a CCD (charge coupled device) or a CMOS (complementary metal oxide semiconductor) are used. The first imaging unit 40 is electrically connected to the control device 100, and its driving is controlled by the control device 100. Note that lighting for imaging is also provided if necessary.

Here, the position of the tablet T in the X direction and the Y direction is, for example, a position in the XY coordinate system with respect to the center (reference position) of the imaging area of the first imaging unit 40. Further, the position in the θ direction is, for example, a position indicating the degree of rotation of the tablet T with respect to the center line in the Y direction of the imaging area of the first imaging unit 40. This position in the θ direction is detected when the tablet T has a directional shape, such as when the tablet T has a score line or when the tablet T is formed into an oval, oval, or square shape. be done.

The printing section 50 has an inkjet head 51. The inkjet head 51 is positioned downstream in the transport direction H1 from the position where the first imaging section 40 is provided, and is provided above the transport belt 21. The inkjet head 51 has a plurality of (for example, several hundred to several thousand) nozzles 51a (see FIG. 2), and the direction in which the nozzles 51a are lined up in a row (nozzle row) is perpendicular to (crosses) the transport direction H1 in a horizontal plane. example). The inkjet head 51 discharges ink individually from each nozzle 51a by the operation of a drive element for each nozzle 51a. As the inkjet head 51, various inkjet print heads having drive elements such as piezoelectric elements, heating elements, or magnetostrictive elements are used. The inkjet head 51 is electrically connected to the control device 100, and its driving is controlled by the control device 100.

The second imaging unit 60 is located downstream in the transport direction H1 from the position where the printing unit 50 is provided, and is provided above the transport belt 21. This second imaging unit 60 takes an image at a second imaging timing when the tablet T reaches an imaging position directly below the second imaging unit 60 based on the position information of the tablet T in the X direction detected by the sensor 30. A second image including the top surface of the tablet T is acquired, and the acquired second image is transmitted to the control device 100. The second image is used to inspect the print pattern printed on the tablet T. As the second imaging section 60, as with the first imaging section 40 described above, various cameras having an imaging device such as a CCD or a CMOS are used, for example. The second imaging unit 60 is electrically connected to the control device 100, and its driving is controlled by the control device 100. Illumination for imaging is also provided if necessary.

The cover section 70 is a housing that houses the sensor 30, the first imaging section 40, the inkjet head 51 of the printing section 50, and the second imaging section 60, as shown in FIGS. 1 to 3. This cover part 70 is arranged at a predetermined distance (for example, , 5 to 12 mm) above the upper surface of the conveyor belt 21. Note that, for example, when imaging illumination (for example, line illumination or ring illumination) is provided, that illumination is also provided within the cover section 70.

As shown in FIG. 3, four through holes 70a, 70b, 70c, and 70d are formed in the lower surface of the cover part 70 along the conveyance direction H1. The sensor 30 inside the cover part 70 is provided at a position facing the through hole 70a, and is capable of detecting the tablet T on the conveyor belt 21. Furthermore, the first imaging section 40 inside the cover section 70 is provided at a position facing the through hole 70b, and is capable of imaging the tablets T on the conveyor belt 21. The inkjet head 51 in the cover part 70 is inserted into the through hole 70c and is capable of printing on the tablets T on the conveyor belt 21. The second imaging section 60 inside the cover section 70 is provided at a position facing the through hole 70d, and is capable of imaging the tablets T on the conveyor belt 21.

Each through hole 70a, 70b, 70d is closed with a transparent member 71, 72 such as glass. Each light-transmitting member 71 is provided, for example, on the inner bottom surface of the cover portion 70. Further, the through hole 70c is closed by inserting the inkjet head 51 into the through hole 70c via a sealing member 73 made of silicon or the like. In this way, the cover part 70 is formed in a sealed state, and the inside of the cover part 70 is maintained at, for example, a positive pressure. Note that each of the light-transmitting members 71 and 72 may be provided by being fitted into each of the through-holes 70a, 70b, and 70d, for example, as long as it is possible to close each of the through-holes 70a, 70b, and 70d, and It may be provided on the outer surface of the cover part 70.

The blow device 80 has a plurality of blow parts 81, as shown in FIGS. 1 to 3. These blow parts 81 are provided on the lower surface of the cover part 70 in correspondence with the through holes 70a, 70b, and 70d, that is, the sensor 30, the first imaging part 40, and the second imaging part 60, respectively. Each blow section 81 blows out gas in a direction horizontally orthogonal to the conveying direction H1 (Y direction: see FIG. 2) when viewed from above, and ), that is, gas is blown onto the lower surfaces of the transparent members 71 and 72 that close the through holes 70a, 70b, and 70d. As the gas, for example, air, nitrogen, etc. are used. Each blow section 81 is electrically connected to a control device 100, and each drive is individually controlled by the control device 100.

As shown in FIG. 4, the blowing part 81 blows gas toward the lower surface of the transparent member 71 that closes the through hole 70a, for example, and blows the gas toward the lower surface of the transparent member 71, but the blowing section 81 is not limited to this. isn't it. For example, even if the direction in which the blowing part 81 blows out gas (the direction in which the gas blows out) is toward the lower surface of the transparent member 71, that is, the lower surface of the cover section 70, it is toward the vicinity of or around the lower surface of the cover section 70. It may be a direction. In other words, the direction in which the gas is blown out is not particularly limited as long as the gas blown out from the blow section 81 reaches the lower surface of the cover section 70 .

Returning to FIGS. 1 and 2, the collection unit 90 is located downstream in the transport direction H1 from the position where the second imaging unit 60 is provided, and is located at the downstream end of the transport unit 20 in the transport direction H1. It is provided. The conveyance unit 20 releases the holding of the tablet T when the tablet T on the conveyance belt 21 reaches a predetermined position, for example, the downstream end of the conveyance unit 20 in the conveyance direction H1. The collecting section 90 is configured to separate and collect the tablets T that fall after being released from the holding by the conveying section 20 into defective and non-defective tablets. For example, by blowing gas onto the falling tablets T and changing the falling direction of the tablets T between defective and non-defective products, or by changing the falling path with a member such as a plate, the falling tablets T can be separated into defective and non-defective products. It is possible to collect them separately. For example, defective products include non-printed tablets and tablets that fail printing, and non-defective products include tablets that pass printing. Non-printed tablets include non-printed tablets with foreign substances attached (non-printed tablets with foreign substances attached) and non-printed tablets with no foreign substances attached (non-printed tablets with no foreign substances attached). It is also possible to collect printed tablets separately. The recovery unit 90 is electrically connected to a control device 100, and its driving is controlled by the control device 100.

The control device 100 controls each part of the tablet printing apparatus 1, such as the supply part 10, the conveyance part 20, the sensor 30, the first imaging part 40, the printing part 50, and the second imaging part 60, based on various information and various programs. , the blow device 80, the recovery section 90, etc. The control device 100 also receives detection information (for example, a detection signal) transmitted from the position detector 25 and the sensor 30, and also receives images transmitted from the first imaging unit 40 and the second imaging unit 60. Receive information etc. The control device 100 is realized by, for example, an electronic circuit such as an integrated circuit, a computer, or the like.

(Example of configuration of control device)
Next, a configuration example of the control device 100 will be described with reference to FIG. 5.

As shown in FIG. 5, the control device 100 includes an image processing section 101, a storage section 102, and a control section 103. An input device 100a and an output device 100b are connected to this control device 100. The input device 100a is realized by, for example, a switch, a touch panel, a keyboard, a mouse, or the like. Further, the output device 100b is realized by, for example, a display, a lamp, a meter, or the like.

The image processing unit 101 takes in a first image captured by the first imaging unit 40 and a second image captured by the second imaging unit 60, and processes the images using a known image processing technique. . For example, the image processing unit 101 processes the first image obtained from the first imaging unit 40, obtains the presence or absence of cracks, chips, and stains on the tablet T, and further processes the first image in the X direction and Y direction of the tablet T. and obtain the position in the θ direction. The image processing unit 101 also processes the second image obtained from the second imaging unit 60 and obtains the printing position, shape, and size of the printing pattern (for example, characters or marks) printed on the tablet T. do. The image processing unit 101 stores information on the presence or absence of cracks, chips, and stains on the obtained tablets T, information on the positions of each obtained tablet T in the X direction, Y direction, and θ direction, and the printing position of the printing pattern on each tablet T. information, shape information, and size information to the control unit 103.

The storage unit 102 stores processing information, various programs, and the like. For example, it is realized by a semiconductor memory element such as a RAM (Random Access Memory) or a flash memory, or a storage device such as a hard disk or an optical disk. The storage unit 102 stores print data related to printing, movement speed data of the conveyor belt 21, and the like. The print data includes information on print patterns such as characters and marks.

The control unit 103 is, for example, a computer such as a CPU (Central Processing Unit) or an MPU (Micro Processing Unit), and controls each unit. For example, the control unit 103 controls the supply unit 10, the transport unit 20, the sensor 30, the first imaging unit 40, the printing unit 50, and the second imaging unit based on various information and various programs stored in the storage unit 102. 60, the collection unit 90, the image processing unit 101, the storage unit 102, etc. are controlled. Further, the control unit 103 receives detection signals transmitted from the sensor 30 and the position detector 25, and the like. Note that the control unit 103 is realized by, for example, one or both of hardware and software.

For example, the control section 103 constantly drives each blow section 81 of the blow device 80. Specifically, the control section 103 controls each blow section 81 so that each blow section 81 always blows out gas. In response to this, each blow section 81 always blows out gas and blows it onto the lower surface of the cover section 70. The gas blown out from each blow part 81 is blown onto the lower surface of each light-transmitting member 71, 72 of cover part 70, and foreign matter (for example, powder or dust) adhering to the lower surface of each light-transmitting member 71, 72 is removed. ) are removed. Note that the control device 100 controls regulating valves (not shown) provided in piping (not shown) connected to each blow part 81, and adjusts the flow rate of gas blown out from each blow part 81 and the like. It is possible to adjust the flow rate individually. Usually, the flow rate and flow rate of the gas blown out from each blow section 81 are set in advance and stored in the storage section 102, for example. However, the flow rate and flow rate of the gas blown out from each blow part 81 may be changed according to predetermined conditions, or may be changed according to a user's input operation on the input device 100a. Note that the flow rate and flow rate of the gas from each blowing section 81 can be determined and set in advance by experiments to be optimal depending on the diameter and shape of the tablet T and the conveyance speed of the tablet T.

Further, the control unit 103 acquires the position of the tablet T in the X direction on the conveyor belt 21 based on the detection information transmitted from the sensor 30, that is, the timing at which the tablet T on the conveyor belt 21 is detected, and Based on the position information indicating the position in the X direction of settings, and generates timing information indicating those timings and stores it in the storage unit 102. The printing start timing is the timing at which printing is started on the tablet T that has reached the printing position directly below the inkjet head 51. Note that the control unit 103 can acquire information such as the movement amount (rotation amount) and speed of the conveyor belt 21 based on the detection information transmitted from the position detector 25.

Further, the control unit 103 sets whether printing is possible for the tablet T for which the presence/absence information has been obtained, based on the information on the presence/absence of cracks, chips, and stains on the tablet T transmitted from the image processing unit 101. Then, the control unit 103 sets printing conditions for the tablet T set to be printable. At this time, the control unit 103 sets printing conditions for the tablet T for which position information has been obtained, based on the position information of the tablet T in the X direction, Y direction, and θ direction transmitted from the image processing unit 101. do. For example, the control unit 103 determines the range of the nozzle 51a used for printing the target tablet T in the inkjet head 51, that is, the nozzle range to be used, based on the position information of the tablet T in the Y direction and the print data, and Set printing conditions including nozzle range and print start timing. Note that when the tablet T has a shape with directionality, the control unit 103 sets printing conditions in correspondence with 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 103 registers in the storage unit 102 180 print patterns in which the orientation of the print pattern is rotated by 1 degree in the range of 0 degrees to 179 degrees, and from among these print patterns, A printing pattern with an angle that matches the position of the tablet T in the θ direction is selected and printing conditions are set.

Further, the control unit 103 controls the printing pattern of the tablet T in a predetermined shape and size based on the print position information, shape information, and size information of the print pattern printed on the tablet T transmitted from the image processing unit 101. It is determined whether or not it has been printed at a predetermined position, that is, whether the printing pattern has been correctly printed on the tablet T (printing condition inspection). For example, in determining the shape and size of a print pattern, the control unit 103 registers a print pattern for inspection in the storage unit 102, and combines the print pattern for inspection with the print pattern on the tablet T after actual printing ( The printing pattern printed on the tablet T) is compared.

Note that the control unit 103 appropriately stores various information (for example, information on the presence or absence of cracks, chips, and stains on the tablet T, position information, timing information, printing conditions, printing quality information, etc.) in the storage unit 102. When the tablet T is collected by the collection unit 90, for example, after a predetermined period of time (for example, several seconds) has elapsed since it fell from the downstream end of the transport unit 20 in the transport direction H1, various information is stored in the storage unit 102. delete. However, if this information is needed in subsequent processes, it is also possible to leave the various information for each tablet T without deleting it, or to save it on storage media outside the device. be. When saving various information for each tablet T, link this information with the manufacturing date and time, lot number, etc., and save it so that it can be used retroactively in the event that a defective product occurs after shipping the printed tablet T. It may also be possible to investigate the cause.

(Printing process)
Next, the printing process performed by the above-mentioned tablet printing apparatus 1 will be explained with reference to FIGS. 1 and 2. This printing process also includes an inspection process. Note that various information such as data required for printing and data required for blowing out gas is stored in advance in the storage unit 102.

When the tablet printing device 1 starts the printing process, the motor 24 is driven, and the conveyor belt 21 rotates in the conveyance direction H1 as the motor 24 rotates the drive pulley 22 and the driven pulley 23. While the conveyor belt 21 is rotating in the conveyance direction H1, the tablets T are sequentially supplied from the hopper 11 to the shooter 12, arranged in a line by the shooter 12, and supplied onto the conveyor belt 21 at random rather than at regular intervals. . The tablets T supplied onto the conveyor belt 21 are conveyed in a line on the conveyor belt 21 at a predetermined moving speed.

The tablet T on the conveyor belt 21 is detected by the sensor 30. Specifically, the tablet T on the conveyor belt 21 is detected by the sensor 30 at the timing when it reaches the detection position directly below the sensor 30 (for example, the laser beam irradiation position), and the tablet T is conveyed based on the timing at which the tablet T is detected. The position of the tablet T in the X direction on the belt 21 is recognized by the control unit 103. Then, position information indicating the position of the tablet T in the X direction is generated by the control unit 103 and stored in the storage unit 102.

Next, the tablet T on the conveyor belt 21 is imaged by the first imaging section 40 . Specifically, the tablet T on the conveyor belt 21 is imaged by the first imaging section 40 at the first imaging timing when the tablet T reaches the imaging position directly below the first imaging section 40; The first image obtained by imaging is transmitted to the control device 100. Based on this first image, the image processing unit 101 generates information on the presence or absence of cracks, chips, and dirt on the tablet T, as well as position information on the tablet T in the X direction, Y direction, and θ direction, and stores the information in the storage unit 102. Saved. Based on the information on the presence or absence of cracks, chips, and stains on the tablet T, whether printing is possible on the target tablet T is set, and also based on information such as the position information of the tablet T in the X direction, Y direction, and θ direction, and the printing pattern. , printing conditions including the nozzle range to be used, print start timing, etc. for the tablet T set to be printable (printable tablet T) are set in the storage unit 102. Note that the ejection timing for the tablet T (timing for ejecting ink onto the tablet T) is determined based on the above-mentioned printing start timing (timing for starting printing on the tablet T).

Printing is executed by the printing unit 50 based on this printing condition. That is, the inkjet head 51 of the printing unit 50 is controlled by the control unit 103 so as to print a predetermined printing pattern on the printable tablets T on the conveyor belt 21. Specifically, the printable tablets T on the conveyor belt 21 that have passed below the first imaging unit 40 are printed by the inkjet based on the above-mentioned printing conditions at the printing start timing when they reach the printing position directly below the inkjet head 51. The head 51 prints. In the inkjet head 51, ink is suitably ejected from each nozzle 51a, and a printing pattern (for example, numbers, alphabets, katakana, symbols, figures) is printed on the printing surface, which is the upper surface of the tablet T. The ink applied to this tablet T dries during transportation. Note that a drying section (not shown) that performs drying using gas or heat may be provided, and the ink may be dried by the drying section.

Thereafter, the printed tablets T on the conveyor belt 21 are imaged by the second imaging section 60 . Specifically, the printed tablet T on the conveyor belt 21 is imaged by the second imaging unit 60 at the second imaging timing when the tablet T reaches the imaging position directly below the second imaging unit 60, and the second imaging unit 60 The second image obtained by the imaging unit 60 is transmitted to the control device 100.

This second image is analyzed by the image processing unit 101 of the control device 100. Specifically, the image processing unit 101 acquires information regarding the printed pattern printed on the tablet T, that is, the printing position, shape, and size of the printed pattern. The second image transmitted from the second imaging unit 60 is analyzed by the image processing unit 101, and inspection information indicating the printing position, shape, and size of the printed pattern on the tablet T is generated and stored in the storage unit 102. Saved.

The control unit 103 executes a printing state inspection based on this inspection information. Specifically, the control unit 103 determines whether or not the printing pattern has been correctly printed on the tablet T based on the above-mentioned inspection information regarding the printing position, shape, and size stored in the storage unit 102, and the printing of the tablet T is performed. Print quality information indicating quality is generated and stored in the storage unit 102. For example, in a print condition inspection, the print pattern used for printing is stored in the storage unit 102 as a print pattern for inspection, and non-defective information regarding the predetermined printing position, shape, and size of the print pattern for inspection is stored in the storage unit 102. It is compared with the saved inspection information regarding the printing position, shape, and size of the actual printed printing pattern, and it is determined whether the printing pattern has been correctly printed on the tablet T (pass or fail).

Finally, the tablets T on the conveyor belt 21 are collected by the collecting section 90. Specifically, when the tablet T after inspection is located at the downstream end of the conveyor belt 21 as the conveyor belt 21 moves, it is released from being held by the conveyor belt 21, falls from the conveyor belt 21, and is collected. 90. At this time, the tablets T that are acceptable tablets fall as they are and are collected as non-defective products by the collection unit 90, but the tablets T that are rejected or non-printed tablets are blown with air while falling from the conveyor belt 21 and are returned as non-defective products. The products are collected separately by the collection unit 90 as defective products.

In such a printing process, gas is constantly blown out from all the blowing units 81. The gases blown out from all the blowing parts 81 are transmitted to the lower surface of the cover part 70, that is, to each light-transmitting member 71 facing the sensor 30, the first imaging part 40, and the second imaging part 60 inside the cover part 70. , 72. As a result, foreign matter (such as powder or dust) adhering to the lower surface of each light-transmitting member 71, 72, more specifically, the lower surface of each light-transmitting member 71, 72 exposed from each through-hole 70a, 70b, 70d shown in FIG. ) is removed, the sensor 30 may detect foreign matter attached to the lower surface of the light-transmitting member 71 and falsely detect the tablet T. It is possible to suppress false detection of the tablet T by imaging a foreign object attached to the lower surface of each light-transmitting member 71, 72. In addition, since gas is constantly blown out from all the blow parts 81, it is possible to prevent foreign matter from adhering to the lower surfaces of the light-transmitting members 71, 72 exposed from the through holes 70a, 70b, 70d. In this way, it is possible to suppress erroneous detection due to adhesion of foreign matter, so that printing on the tablet T can be performed efficiently.

Here, for example, when the sensor 30 detects a foreign object attached to the lower surface of the light-transmitting member 71, an erroneous detection occurs in which the timing at which the tablet T arrives directly below the sensor 30 is incorrectly detected. Accurate printing is not performed on this erroneously detected tablet T, and the tablet T is discharged as a rejected tablet (defective product). In addition, when the first imaging section 40, the second imaging section 60, or other imaging section images and detects a foreign object attached to the lower surface of the transparent members 71, 72, an error may occur that a foreign object is attached to the tablet T. Detection occurs. Printing is not performed on this erroneously detected tablet T, and the tablet T is discharged as a non-printed tablet (defective product). If foreign matter adheres to the lower surface of each of the light-transmitting members 71 and 72, that is, the lower surface of the cover section 70, printing on the tablet T cannot be performed efficiently. By removing foreign matter from the lower surface of the portion 70, it is possible to suppress false detection due to adhesion of foreign matter and efficiently print on the tablet T.

Further, the blowing direction of the gas by the blowing part 81 is a direction horizontally orthogonal to the conveying direction H1 in plan view. As a result, the tablet T is exposed to the airflow only when passing under the blowing part 81 at least, so that the gas blown out from the blowing part 81 can be prevented from affecting the posture of the tablet T. For example, if the blowing direction of the gas by the blowing section 81 is parallel to the transport direction H1, the airflow will hit the plurality of tablets T lined up in the transport direction for a long time, and the posture of the plurality of tablets T will change. It is possible that it may be changed. If the posture of the tablet T is changed, the position of the tablet T detected by the sensor 30 and the position and posture of the tablet T imaged by the first imaging section 40 will change. In other words, subsequent imaging and printing will not go well, making it difficult to efficiently print on the tablet T. Further, it is possible to suppress the gas blown out from the blow section 81 from affecting printing by the inkjet head 51. For example, if the traveling direction of the ink ejected from the inkjet head 51 is bent by airflow, printing defects will occur, making it difficult to efficiently print on the tablet T. Therefore, the direction in which the gas is blown is in a direction that intersects horizontally with the transport direction H1 in a plan view and that avoids directly below the inkjet head 51 (for example, a direction that is not toward the downstream side of the transport direction H1). It is desirable that there be a direction, and a direction perpendicular to the transport direction H1 is most desirable.

Note that if the tablet T to be printed is a tablet formed by hardening powder, such as a plain tablet or an OD tablet (orally disintegrating tablet), the powder of the tablet T may accumulate on the conveyor belt 21 or Since the powder floats, the powder tends to adhere to the lower surface of the cover portion 70. Therefore, depending on the type of tablet T, the strength of the gas flow blown out from each blow section 81 may be changed. For example, if the type of tablet T is a plain tablet or OD tablet, the gas flow may be strengthened, and if the type of tablet T is a tablet that does not easily release foreign substances (for example, powder), the gas flow may be weakened. Furthermore, when the gas flow is strengthened, it may be returned to its original strength.

(Example of processing for adjusting gas blowing strength)
Next, processing examples 1 to 6 for adjusting gas blowing strength will be described with reference to FIGS. 6 to 11. Each of these processes from Processing Example 1 to Processing Example 6 may be used alone, or may be used in appropriate combinations in parallel or serially.

(Processing example 1)
As shown in FIG. 6, in processing example 1, in step S1, the control unit 103 controls each blowing unit 81 so that the flow of gas blown out from each blowing unit 81 has a first strength. . Thereafter, in step S2, the control unit 103 determines whether the sensor 30 continues to detect the tablet T for a predetermined period of time or longer.

In step S2, when the control unit 103 determines that the state in which the sensor 30 detects the tablet T has been maintained for a predetermined period of time or more (Yes in step S2), in step S3, the control unit 103 determines that the sensor 30 is detected by the sensor 30 among the blowing units 81. The blow part 81 corresponding to the sensor 30 is controlled so that the flow of gas blown out from the blow part 81 is changed from the first strength to the second strength. After that, the process returns to step S2. Note that the second strength is stronger than the first strength (second strength>first strength).

On the other hand, in step S2, if the control unit 103 determines that the state in which the sensor 30 detects the tablet T has not been maintained for a predetermined period of time or more (No in step S2), in step S4, each blow unit 81 The flow of gas blown out from the blowing part 81 corresponding to the sensor 30 among the blowing parts 81 is changed from the second strength to the first strength so as to maintain the flow of the gas blown out at the first strength. The blow section 81 corresponding to the sensor 30 is controlled to restore the strength. After that, the process returns to step S2.

Here, the state in which the sensor 30 such as a laser displacement meter is detecting the tablet T is the state in which the output value (detection value) of the sensor 30 is ON, and the state in which the sensor 30 is detecting the tablet T. Whether or not the output value of the sensor 30 has been maintained for a predetermined time or longer is determined by whether or not the output value of the sensor 30 has been "ON" for a predetermined time or longer. If the sensor 30 does not make a false detection, it will turn "ON" every time the tablet T is conveyed directly below the sensor 30, and it will turn "OFF" when the tablet T is no longer located below the sensor 30. repeat. That is, during normal operation, the sensor 30 alternately repeats "ON" and "OFF". In the event of an abnormality (false detection), the "ON" state continues for a predetermined period of time or longer. This judgment process is the same in other processing examples, for example.

Further, the first strength and the second strength are predetermined values. The strength of the gas flow changes when the flow rate, flow rate, etc. of the gas is changed. For example, by increasing the gas flow rate or increasing the gas flow rate, the gas flow is strengthened, and conversely, by decreasing the gas flow rate or reducing the gas flow rate, The gas flow is weakened. The above-mentioned predetermined time is set to be longer than, for example, the time during which the sensor 30 maintains the state in which it detects the tablet T under normal conditions (other than abnormal conditions). Although information such as the first strength, second strength, and predetermined time period is set in advance in the storage unit 102, it may be changed according to the user's input operation on the input device 100a.

Note that when the sensor 30 does not maintain the state in which it detects the tablet T for a predetermined period of time or longer, the control unit 103 controls the sensor 30 to return the gas flow from the second strength to the first strength. The corresponding blow section 81 is controlled, but the invention is not limited to this. For example, if a predetermined period of time has elapsed since the gas flow was strengthened in step S3, the gas flow is changed from the second strength to the first strength. The blow section 81 corresponding to the sensor 30 may be controlled to restore the strength. In this case, the process of step S4 can be made unnecessary.

In addition, an output device such as a display, a lamp, a meter, etc. can be used to indicate whether the strength of the gas flow is the first strength or the second strength, or whether it is becoming stronger or weaker. 100b may be used to notify the user. This allows the user to grasp how strong the gas flow is.

According to Processing Example 1, if the state in which the sensor 30 detects the tablet T is maintained for a predetermined period of time or more, the object detected by the sensor 30 as the tablet T is not the tablet T, but is detected by the sensor 30. It is determined that it is a foreign object (for example, powder or dust) adhering to the lower surface of the corresponding light-transmitting member 71, and the flow of gas blown out from the blow section 81 corresponding to the sensor 30 is strengthened. As a result, foreign matter adhering to the lower surface of the light-transmitting member 71 corresponding to the sensor 30, specifically, the lower surface of the light-transmitting member 71 exposed from the through hole 70a shown in FIG. Erroneous detection of arrival can be suppressed.

Here, the above-mentioned predetermined time is set to a time when the possibility that the tablets T are conveyed in succession is extremely low, such as a time longer than the time it takes for 10 tablets T to pass through. In other words, the "ON" output of the sensor 30 does not continue because the tablets T are conveyed in a continuous manner, but the "ON" output continues due to foreign matter adhering to the cover 70. The amount of time that can be estimated to be running is determined in advance through experiments, etc., and this is set.

Note that even though the tablet detection by the sensor 30 is maintained for a predetermined time or more in step S2 and the gas flow is changed to the second strength in step S3, the tablet detection by the sensor 30 is maintained for a predetermined time in step S2 again. If this continues, the process may be interrupted and maintenance processing may be performed. This also applies to subsequent processing examples 2 to 6.

(Processing example 2)
As shown in FIG. 7, in processing example 2, in step S11, the control unit 103 controls each blowing unit 81 so that the flow of gas blown out from each blowing unit 81 has a first strength. . Thereafter, in step S12, the control unit 103 determines whether the state in which the sensor 30 detects the tablet T has been maintained for a predetermined time or more, and in step S13, the control unit 103 determines whether the sensor 30 detects the tablet T or not. It is determined whether or not the tablet T is present in the captured image obtained by the unit 60.

In step S12, the control unit 103 determines that the state in which the sensor 30 detects the tablet T has been maintained for a predetermined period of time or longer (Yes in step S12), and in step S13, the control unit 103 determines that the tablet T is not present in the captured image. If it is determined (Yes in step S13), the object detected by the sensor 30 is not a tablet T because the tablet T does not exist in the captured image even though it is detected as a tablet T by the sensor 30. , it is determined that it is a foreign object (for example, powder or dust) adhering to the lower surface of the light-transmitting member 71 corresponding to the sensor 30, and in step S14, the air is blown out from the blow part 81 corresponding to the sensor 30 among the blow parts 81. The blow section 81 corresponding to the sensor 30 is controlled so that the flow of gas is changed from the first strength to the second strength. After that, the process returns to step S12.

On the other hand, in step S12, if the control unit 103 determines that the state in which the sensor 30 detects the tablet T has not been maintained for a predetermined period of time or more (No in step S12), or in step S13, If it is determined that the tablet T exists (No in step S13), in step S15, the flow of gas blown out from each blowing part 81 is maintained at the first strength, or the sensor in each blowing part 81 is The blow part 81 corresponding to the sensor 30 is controlled so that the flow of gas blown out from the blow part 81 corresponding to the sensor 30 is returned from the second strength to the first strength. After that, the process returns to step S12.

According to such processing example 2, even though the sensor 30 maintains the state in which it detects the tablet T for a predetermined period of time or more, the first imaging unit 40 or the second imaging unit 60 detects the tablet T. When the tablet T does not exist in the captured image, the flow of gas blown out from the blow part 81 corresponding to the sensor 30 is strengthened. As a result, foreign matter adhering to the lower surface of the light-transmitting member 71 corresponding to the sensor 30, specifically, the lower surface of the light-transmitting member 71 exposed from the through hole 70a shown in FIG. It is possible to reliably prevent false detection of arrival.

(Processing example 3)
As shown in FIG. 8, in step S21, in processing example 3, the control unit 103 controls each blowing unit 81 so that the flow of gas blown out from each blowing unit 81 has a first strength. . After that, in step S22, the control unit 103 determines that a predetermined number of foreign objects (predetermined number of captured images) or more are found in one or both of the captured images obtained by the first imaging unit 40 and the second imaging unit 60. Determine whether or not.

In step S22, if the control unit 103 determines that a predetermined number or more of foreign objects are found in one or both of the captured images (Yes in step S22), the control unit 103 acquires captured images in which a predetermined number or more of foreign objects are found. The flow of gas blown out from the blowing section 81 corresponding to the imaging section (one or both of the first imaging section 40 and the second imaging section 60) is changed from the first strength to the second strength. The corresponding blow section 81 is controlled. After that, the process returns to step S22.

On the other hand, in step S22, if the control unit 103 determines that no more than a predetermined number of foreign objects are observed in one or both of the captured images (No in step S22), in step S24, the control unit 103 blows out foreign objects from each blow unit 81. In order to maintain the gas flow at the first strength, or to maintain the gas flow blown out from the blowing section 81 corresponding to the imaging section that has acquired the captured images in which a predetermined number or more of foreign objects are observed, the gas flow blown out from the blowing section 81 is set at the second strength. The blow section 81 in question is controlled so as to return the strength to the first strength. After that, the process returns to step S22.

According to processing example 3, if a predetermined number or more of foreign objects are found in one or both of the captured images obtained by the first imaging unit 40 and the second imaging unit 60, The flow of gas blown out from the blowing section 81 corresponding to the imaging section (one or both of the first imaging section 40 and the second imaging section 60) that acquired the recognized captured image is strengthened. In other words, if a predetermined number of foreign objects are observed at the same position in the captured images, it is determined that the foreign objects are not particles attached to the tablet T, but particles attached to the cover section 70, and the corresponding blow section 81 The flow of gas blown out is strengthened. Thereby, the lower surface of the light-transmitting member 71 for the first imaging unit 40 and the light-transmitting member 72 for the second imaging unit 60, specifically, each light-transmitting member 71 exposed from each through hole 70b, 70d shown in FIG. Since the foreign matter attached to the lower surface of the tablet T is removed, the imaging section such as the first imaging section 40 or the second imaging section 60 images the foreign matter attached to the lower surface of the transparent members 71 and 72. It is possible to suppress false detections.

Here, the predetermined number of images is set as the number of a plurality of captured images obtained by capturing images of different tablets T with the same imaging unit. For example, if a foreign object is found at the same position (within the same range) in five images taken sequentially by the first imaging unit 40 of a plurality of tablets T being transported, then the foreign object present in the images is It is determined that the foreign object is not attached to the tablet T but is attached to the lower surface of the cover portion 70. If the same tablet is imaged by the first imaging unit 40 and the second imaging unit 60, and a foreign object is found at the same position in these two captured images, there is a possibility that the foreign object is attached to the tablet T. is high. On the other hand, if a predetermined number or more of foreign objects are observed in the captured images of different tablets T, it can be inferred that a foreign object is attached to the cover portion 70.

Note that it is determined whether or not a predetermined number or more of foreign objects are observed in the captured images, but instead of the predetermined number, a predetermined time period, which is the time required to obtain a predetermined number of captured images, may be used. For example, if the intervals between the tablets T arranged in a row on the conveyor belt 21 are not constant but irregular, it is desirable to use a predetermined number of tablets. On the other hand, when the intervals between the tablets T arranged in a row on the conveyor belt 21 are constant, a predetermined number of tablets or a predetermined time is used.

(Processing example 4)
As shown in FIG. 9, processing example 4 has basically the same processing flow as processing example 3, but in processing example 4, step S32 is performed instead of step S22 (see FIG. 8) of processing example 3. In one or both of the captured images obtained by the first imaging unit 40 and the second imaging unit 60, the control unit 103 selects a position where the tablet T does not exist (an area where the tablet T does not exist in the captured image). It is determined whether or not foreign matter is found on a predetermined number of sheets or more. The flow of the subsequent process is the same as in Processing Example 3.

According to Processing Example 4, in one or both of the captured images obtained by the first imaging unit 40 and the second imaging unit 60, a foreign object is observed at a position where no tablet T is present, and The flow of gas blown out from the blowing section 81 corresponding to the imaging section (one or both of the first imaging section 40 and the second imaging section 60) that has acquired the captured images in which the foreign object is recognized in a predetermined number or more is strong. be done. In other words, if a foreign object is found to be attached to a position where the tablet T is not present in the captured image for a predetermined number of images (for a predetermined time) or more, the foreign object is determined to be powder or dust attached to the cover part 70, and the first It is determined that the foreign matter cannot be removed by blowing at such a strength, and the flow of gas blown out from the corresponding blow section 81 is strengthened. Thereby, the lower surface of the light-transmitting member 71 for the first imaging unit 40 and the light-transmitting member 72 for the second imaging unit 60, specifically, each light-transmitting member 71 exposed from each through hole 70b, 70d shown in FIG. Since the foreign matter attached to the lower surface of the tablet T is removed, the imaging section such as the first imaging section 40 or the second imaging section 60 images the foreign matter attached to the lower surface of the transparent members 71 and 72. It is possible to suppress false detections.

(Processing example 5)
As shown in FIG. 10, processing example 5 has basically the same processing flow as processing example 3, but in processing example 5, step S42 is performed instead of step S22 (see FIG. 8) of processing example 3. , the control unit 103 determines whether or not there is a foreign object or whether the positions of the foreign object do not match in both of the captured images (two captured images) obtained by the first imaging unit 40 and the second imaging unit 60. to decide. The flow of the subsequent process is the same as in Processing Example 3, but in step S23, the control unit 103 controls the blowout from each blow unit 81 corresponding to both the first imaging unit 40 and the second imaging unit 60. Each blow section 81 is controlled to change the flow of gas from the first strength to the second strength.

According to processing example 5, if the presence or absence of a foreign object or the position of the foreign object do not match in both of the captured images obtained by the first imaging unit 40 and the second imaging unit 60, the first The flow of gas blown out from each blow section 81 corresponding to both the imaging section 40 and the second imaging section 60 is strengthened. In other words, if the presence or absence or position of a foreign object does not match between the image taken by the first imaging section 40 and the image taken by the second imaging section 60 for the same tablet T, the foreign object will adhere to the tablet T. It is determined that the powder or dust is not powder or dust attached to the cover part 70, and the flow of gas blown out from each blow part 81 is strengthened. Thereby, the lower surface of the light-transmitting member 71 for the first imaging unit 40 and the light-transmitting member 72 for the second imaging unit 60, specifically, each light-transmitting member 71 exposed from each through hole 70b, 70d shown in FIG. Since the foreign matter attached to the lower surface of the tablet T is removed, the imaging section such as the first imaging section 40 or the second imaging section 60 images the foreign matter attached to the lower surface of the transparent members 71 and 72. It is possible to suppress false detections.

(Processing example 6)
As shown in FIG. 11, processing example 6 basically has the same processing flow as processing example 3, but in processing example 6, step S52 is performed instead of step S22 (see FIG. 8) of processing example 3. , the control unit 103 determines whether or not the inkjet head 51 is undergoing maintenance. The flow of the subsequent process is the same as in Processing Example 3, but in step S23, the control unit 103 changes the flow of gas blown out from all the blowing units 81 from the first strength to the second strength. All applicable blow sections 81 are controlled so as to do so.

According to processing example 6, when the inkjet head 51 is under maintenance, the flow of gas blown out from all the blowing parts 81 is strengthened. As a result, during maintenance, the lower surfaces of the light-transmitting members 71 and 72 for the sensor 30, the first imaging section 40, and the second imaging section 60 are exposed through the through holes 70a, 70b, and 70d shown in FIG. Since the foreign matter attached to the lower surface of each light-transmitting member 71, 72 is removed, the sensor 30 can detect the foreign matter attached to the lower surface of the light-transmitting member 71 and erroneously detect the tablet T. It is possible to prevent the imaging section 40, the second imaging section 60, or other imaging section from erroneously detecting the tablet T by imaging a foreign object attached to the lower surface of the light-transmitting members 71, 72.

Note that whether or not the inkjet head 51 is under maintenance is determined, for example, when the sensor 30, the first imaging unit 40, and the second imaging unit 60 do not detect the tablet T for a predetermined period of time or more. can be judged. Alternatively, the control device 100 may detect that the "maintenance mode" has been selected by the operator and determine that maintenance is being performed.

Normally, during maintenance, the tablets T are not present on the conveyor belt 21, and the posture of the tablets T does not change due to the flow of gas blown out from each blowing part 81, so a strong airflow may occur. Furthermore, during maintenance of the inkjet head 51, droplets may be sucked by the suction unit provided in the maintenance section, which causes an air flow to fly up powder and dirt adhering to the inkjet head 51. However, by strengthening the flow of gas blown out from each blow part 81, it is possible to suppress the flying powder, dirt, etc. from adhering to the lower surface of the cover part 70. Moreover, even if the powder, dirt, etc. that fly up and adhere to the lower surface of the cover part 70, it is possible to remove the powder, dirt, etc.

As described above, according to the first embodiment, the tablet printing apparatus 1 includes a detection unit (for example, the sensor 30, the first imaging unit 40, or the second When viewed from above, the imaging section 60), the inkjet head 51 that prints on the tablet T detected by the detection section, the cover section 70 that covers the detection section, and the surface of the cover section 70 on the conveyor belt 21 side are shown. It includes a blow section 81 that blows gas in a direction horizontally intersecting the transport direction H1 of the tablet T, and a control section 103 that controls the blow section 81. As a result, gas is blown onto the lower surface of the cover section 70 by the blow section 81, and foreign matter (e.g., powder and dust) attached to the lower surface of the cover section 70 is removed, so that the detection section does not adhere to the lower surface of the cover section 70. This makes it possible to prevent false detection of the tablet T by detecting foreign matter. Therefore, false detection due to adhesion of foreign matter can be suppressed, and printing on the tablet T can be performed efficiently.

<Second embodiment>
A second embodiment will be described with reference to FIG. 12.

In the second embodiment, as shown in FIG. 12, the tablets T are conveyed in two rows. In this case, the supply unit 10 supplies the tablets T to the conveyor belt 21 in two rows. In the example of FIG. 12, the tablets T are conveyed in two rows, but the invention is not limited to this. When the tablets T are conveyed in two rows, the sensor 30, the first imaging section 40, and the second imaging section 60 are provided for each row. Note that, although the inkjet head 51 is provided in common to each column, the inkjet head 51 is not limited to this, and may be provided in each column.

The blow section 81 is provided for each of the plurality of sensors 30, the plurality of first imaging sections 40, and the plurality of second imaging sections 60. In the example of FIG. 12, six blow parts 81 are provided, and they are arranged in two rows in the conveyance direction H1. The blowing section 81 for each row blows gas toward the outside while avoiding the inside of each row. Specifically, each blow part 81 is provided on the lower surface of the cover part 70 so as to be located between two rows of the plurality of suction holes 21a in a plan view. These blow parts 81 each blow out gas in opposite directions toward the outside of the space between the cover part 70 and the conveyor belt 21 along the lower surface of the cover part 70 .

In addition, when conveying in multiple rows of three or more rows, each blow part 81 is configured to blow out gas toward the outside. At this time, the blowing section 81 corresponding to the conveyance line located on the inside blows gas toward the tablets T of the conveyance line located on the outside, but toward the outside (that is, the direction in which there are fewer adjacent conveyance lines). By blowing out the gas, it is possible to minimize the risk that the gas blown out from the blow section 81 will affect the posture of the tablet T.

According to such a configuration, the gas blowing direction is a direction that horizontally intersects with the conveyance direction H1 in a plan view, and is a direction that does not face the adjacent conveyor rows, that is, a direction that faces outside of the adjacent conveyor rows. . As a result, the tablet T is exposed to the airflow only when passing under the blowing part 81 at least, so that it is possible to suppress the influence of the airflow caused by the gas blowing on the posture of the tablet T, so that printing on the tablet T can be performed efficiently. I can do it. Moreover, since the gas blown out from the blowing part 81 can be suppressed from affecting the printing of the inkjet head 51, printing on the tablet T can be performed efficiently.

Note that although the blowing directions of the individual gases of the blowing portions 81 arranged in the conveying direction H1 are the same, the directions are not limited to this and may be different. Furthermore, since the blowing direction of each gas from each blowing section 81 is a direction that horizontally intersects the conveying direction H1 in a plan view, even if the direction is inclined toward the upstream side of the conveying direction H in a plan view, Although the direction may be inclined toward the downstream side in the transport direction H when viewed, it is preferably the direction inclined toward the opposite side to the inkjet head 51 side in order to suppress the blowing of gas toward the inkjet head 51 side. For example, the blowing direction of each gas of each blowing section 81 corresponding to the sensor 30 and the first imaging section 40 is a direction that is inclined toward the upstream side of the conveying direction H1 in plan view, and The blowing direction of the gas from the corresponding blowing section 81 is preferably a direction that is inclined downstream in the conveying direction H1 in plan view.

As explained above, according to the second embodiment, the same effects as the first embodiment can be obtained. Furthermore, even when the tablets T are conveyed in multiple rows, the influence of the airflow caused by the gas blowout on the posture of the tablets T and the printing of the inkjet head 51 can be suppressed, making it possible to efficiently print on the tablets T. .

<Other embodiments>
In the above description, the tablet T is printed using the tablet printing device 1 (tablet printing method) according to one embodiment; In other words, printing is performed on the tablet T using the printing method to produce a printed tablet T. That is, the tablet printing device 1 can be translated into a tablet manufacturing device, and the tablet printing method can be translated into a tablet manufacturing method.

Furthermore, in the above description, the tablets T are conveyed in one or two rows, but the number of rows is not limited to this, and the number of rows may be three or five or more, and is not particularly limited. The number of conveyor belts 21 may be two or more, and is not particularly limited. Further, the number of inkjet heads 51 may be two or more, and is not particularly limited.

Further, in the above description, a print head in which the nozzles 51a are arranged in one row is illustrated as the inkjet head 51, but the present invention is not limited to this. For example, a print head in which the nozzles 51a are arranged in a plurality of rows may be used. good. Alternatively, a plurality of inkjet heads 51 may be used in a horizontal plane in a direction orthogonal to the transport direction H1.

Further, in the above description, the inkjet head 51 is provided so that the direction in which the nozzles 51a are lined up is perpendicular to the conveying direction H1 in the horizontal plane, but the present invention is not limited to this. For example, the nozzles 51a They may be provided so that the direction in which they are lined up is a direction that intersects the conveyance direction H1 in a horizontal plane.

Furthermore, in the above description, printing on one side of the tablet T was illustrated, but the invention is not limited to this. The imaging section 60 of the image pickup section 60 is formed into one unit, and the units are stacked one on top of the other, and the tablet T printed by the upper conveyance section 20 is reversed and delivered to the lower conveyance section 20, and both sides of the tablet T are printed. You may also do so.

Furthermore, in the above description, the tablets T are supplied on the conveyor belt 21 at random rather than at regular intervals, but the present invention is not limited to this, and they may be supplied at regular intervals. Furthermore, in the above description, the tablets T are sucked and held by the suction holes 21a formed on the conveyor belt 21, but the invention is not limited to this. Alternatively, it may be held on the conveyor belt 21 by its own weight and conveyed.

Here, the above-mentioned tablets T can include tablets used for medicine, for eating and drinking, for cleaning, for industrial purposes, or for aromatic purposes. Tablets T include plain tablets, sugar-coated tablets, film-coated tablets, enteric-coated tablets, gelatin-encapsulated tablets, multilayer tablets, and hard-coated tablets, as well as various capsule tablets such as hard capsules and soft capsules. It can be included in tablet T. Further, the shape of the tablet T includes various shapes such as a disk shape, a lens shape, a triangle, and an ellipse. Furthermore, when the tablet T to be printed is for pharmaceutical use or food or drink use, edible ink is suitable as the ink to be used. As this edible ink, any of synthetic pigment ink, natural pigment ink, dye ink, and pigment ink may be used.

Although several embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included within the scope and gist of the invention, as well as within the scope of the invention described in the claims and its equivalents.

1 Tablet printing device 10 Supply section 11 Hopper 12 Shooter 20 Conveyance section 21 Conveyance belt 21a Suction hole 22 Drive pulley 23 Followed pulley 24 Motor 25 Position detector 26 Suction chamber 30 Sensor 40 First imaging section 50 Printing section 51 Inkjet head 51a Nozzle 60 Second imaging section 70 Cover section 70a Through hole 70b Through hole 70c Through hole 70d Through hole 71 Transparent member 72 Transparent member 73 Sealing member 80 Blow device 81 Blow section 90 Collection section 100 Control device 100a Input device 100b Output Apparatus 101 Image processing section 102 Storage section 103 Control section T Tablet H1 Conveyance direction

Claims (10)

a detection unit that detects tablets conveyed by the conveyor belt;
an inkjet head that prints on the tablet detected by the detection unit;
a cover part that covers the detection part;
a blowing part that blows gas against a surface of the cover part on the conveying belt side in a direction horizontally intersecting the conveying direction of the tablets in a plan view;
a control unit that controls the blow unit;
A tablet printing device comprising: When the tablets are transported in multiple rows by the transport belt, the detection unit is provided for each row,
The cover section covers the plurality of detection sections,
The blow section is provided for each detection section,
The blowing section for each of the detection sections blows out the gas toward the outside while avoiding the inside of the plurality of rows.
The tablet printing device according to claim 1. When the control unit determines that the detection unit has maintained a state in which the tablet is detected for a predetermined period of time or more, the control unit controls the blow unit so that the gas flow becomes stronger.
The tablet printing device according to claim 1. A plurality of the detection units are provided,
The cover section covers the plurality of detection sections,
A first detection unit among the plurality of detection units detects the arrival of the tablets conveyed by the conveyance belt,
A second detection unit among the plurality of detection units images the tablet conveyed by the conveyance belt,
The control unit determines that the state in which the first detection unit detects the tablet is maintained for a predetermined period of time or more, and the tablet is not present in the image obtained by the second detection unit. If it is determined that the gas flow is strong, the blow section is controlled so that the gas flow becomes stronger;
The tablet printing device according to claim 1. The detection unit images the tablet being conveyed by the conveyor belt,
When the control unit determines that a foreign object is observed at the same position in the images obtained by the detection unit for a predetermined number of images or for a predetermined period of time or more, the control unit controls the blow unit so that the flow of the gas becomes stronger.
The tablet printing device according to claim 1. The detection unit images the tablet being conveyed by the conveyor belt,
When the control unit determines that a foreign object is observed in a position where the tablet does not exist in the image obtained by the detection unit, the control unit controls the blow unit so that the flow of the gas becomes stronger.
The tablet printing device according to claim 1. A plurality of the detection units are provided,
The cover section covers the plurality of detection sections,
A first detection unit among the plurality of detection units is provided upstream of the inkjet head in the conveyance direction of the tablet, and images the tablet conveyed by the conveyance belt,
A second detection unit among the plurality of detection units is provided downstream from the inkjet head in the tablet conveyance direction, and images the tablet conveyed by the conveyance belt,
When the control unit determines that the presence or absence of a foreign object or the position of the foreign object do not match in the first image obtained by the first detection unit and the second image obtained by the second detection unit; , controlling the blow section so that the gas flow becomes stronger;
The tablet printing device according to claim 1. When the control unit determines that the inkjet head is undergoing maintenance, the control unit controls the blow unit so that the gas flow becomes stronger.
The tablet printing device according to claim 1. If the control unit determines that the detection unit does not maintain the state of detecting the tablet for a predetermined period of time or longer after controlling the blow unit so that the flow of the gas becomes stronger, the control unit controls the flow of the gas. controlling the blow section so that the flow returns to the strength before it became stronger;
The tablet printing device according to any one of claims 3 to 8. The detection unit detects the tablets conveyed by the conveyor belt;
an inkjet head printing on the tablet detected by the detection unit;
A blowing unit blows gas against a surface of a cover unit that covers the detection unit on the conveying belt side in a direction that intersects horizontally with the conveying direction of the tablet in a plan view;
a control unit controlling the blow unit;
Tablet printing methods including.

Images