JP2023050476A - Tablet printing device and tablet printing method - Google Patents

Abstract

To execute efficient tablet printing.SOLUTION: A tablet printing device 1 includes: a conveyance part 21 for conveying tablets T by a conveyance belt 21a; a detection part 22 for detecting the conveyed tablets T; an inkjet head 24 for discharging ink to the tablets T detected by the detection part 22; a moving mechanism 26 for moving the conveyance belt 21a or the inkjet head 24 so as to change an interval between a surface on a conveyance belt 21a side of the inkjet head 24 and a surface on an inkjet head 24 side of the conveyance belt 21a; and a control part (e.g., a control device 40) for controlling the conveyance part 21 and the moving mechanism 26. The detection part 22 detects height information on the tablets T on the conveyance belt 21a. The control part controls the conveyance part 21 so as to decrease a conveyance speed of the conveyance belt 21a when the height of the tablets T exceeds a predetermined threshold on the basis of the height information, and controls the moving mechanism 26 so as to widen the interval.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD Embodiments of the present invention relate to a tablet printing apparatus and a tablet printing method.

Currently, in order to print various information such as identification information on a tablet, a tablet printing apparatus that performs printing using an inkjet head is being developed. In this tablet printing apparatus, tablets are conveyed by a conveying belt, and at this time, the tablets are held on the conveying belt by suction or storage pockets. Normally, tablets are held on a conveyor belt in a lying state (e.g., if the tablets are flat tablets, they are in a nearly flat state), but they are held in an upright state (e.g., if the tablets are flat tablets, , nearly vertical). When the standing tablet reaches directly under the inkjet head, it may collide with and damage the inkjet head, and the colliding tablet may break.

If a tablet collides with the inkjet head, the nozzles of the inkjet head may be damaged, rendering the inkjet head unusable. In addition, when the tablet is broken, a large amount of tablet powder adheres to the nozzle of the inkjet head, which may hinder good ejection from the nozzle. Therefore, the frequency of maintenance of the inkjet head is increased, or the maintenance time is lengthened. Due to such an increase in the number of times of maintenance, an extension of maintenance time, and breakage of the tablet itself, it is difficult to print on the tablet efficiently.

JP 2019-58220 A

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

A tablet printing apparatus according to an embodiment of the present invention includes a conveying unit that conveys tablets by a conveying belt, a detecting unit that detects tablets conveyed by the conveying belt, and the tablets detected by the detecting unit. an inkjet head that ejects ink; and a moving mechanism that moves the transport belt or the inkjet head so as to change the distance between the transport belt-side surface of the inkjet head and the inkjet head-side surface of the transport belt; a control unit that controls the conveying unit and the moving mechanism; the detecting unit detects height information of the tablets on the conveying belt; When the height of the tablet exceeds a predetermined threshold value, the conveying unit is controlled to reduce the conveying speed of the conveying belt, and the moving mechanism is controlled to widen the interval.

A tablet printing method according to an embodiment of the present invention includes: a conveying unit conveying tablets by a conveying belt; a detecting unit detecting the tablets conveyed by the conveying belt; Ink is ejected onto the tablets detected by the detection unit, and a moving mechanism changes the distance between the surface of the inkjet head on the side of the conveying belt and the surface of the conveying belt on the side of the ink jet head. moving the conveying belt or the inkjet head; and controlling the conveying unit and the moving mechanism by a control unit, wherein the detecting unit detects height information of the tablet on the conveying belt. based on the height information, when the height of the tablet exceeds a predetermined threshold value, the control unit controls the conveying unit to reduce the conveying speed of the conveying belt, and reduces the interval The moving mechanism is controlled so as to widen the .

ADVANTAGE OF THE INVENTION According to embodiment of this invention, a tablet can be printed efficiently.

BRIEF DESCRIPTION OF THE DRAWINGS It is a 1st figure which shows an example of schematic structure of the tablet printing apparatus which concerns on 1st Embodiment. It is a 2nd figure which shows an example of schematic structure of the tablet printing apparatus which concerns on 1st Embodiment. It is a figure showing an example of a schematic structure of a control device concerning a 1st embodiment. It is a figure which shows an example of schematic structure of the moving mechanism which concerns on 1st Embodiment. 4 is a flow chart showing an example of the flow of a printing process according to the first embodiment; It is a figure which shows an example of schematic structure of the tablet printing apparatus which concerns on 2nd Embodiment.

<First Embodiment>
A first embodiment will be described with reference to FIGS. 1 to 5. FIG.

(Configuration example of tablet printing device)
As shown in FIG. 1, the tablet printing apparatus 1 according to the first embodiment includes a supply device 10, a printing device 20, a recovery device 30, and a control device 40.

The supply device 10 has a hopper 11 , an alignment feeder 12 and a delivery feeder 13 . The supply device 10 is positioned on one end side of the printing device 20 and is configured to be able to supply tablets T, which are objects to be printed, to the printing device 20 . The hopper 11 accommodates a large number of tablets T and sequentially supplies the accommodated tablets T to the alignment feeder 12 . The aligning feeder 12 aligns the supplied tablets T in a row and conveys them toward the delivery feeder 13 in the conveying direction A1 (clockwise direction). The delivery feeder 13 sequentially sucks and holds the tablets T arranged in a line on the alignment feeder 12 from the upper side of the tablets T, conveys the held tablets T in a line to the printing device 20, and delivers them to the printing device 20. - 特許庁As the alignment feeder 12, for example, a belt conveying mechanism or a vibrating feeder is used. A belt conveying mechanism, for example, is used as the delivery feeder 13 . The belt conveying mechanism of the delivery feeder 13 rotates in the conveying direction A2 (counterclockwise direction). The supply device 10 is electrically connected to the control device 40 and its driving is controlled by the control device 40 .

The printing device 20 includes a transport section 21 , a detection section 22 , a first imaging section 23 , an inkjet head 24 , a second imaging section 25 , a moving mechanism 26 and a drying section 27 .

The transport section 21 has a transport 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 stretched over the driving pulley 21b and the driven pulleys 21c. The drive pulley 21b and the driven pulleys 21c are rotatably provided in the apparatus main body (not shown), and the drive pulley 21b is connected to the motor 21d. The motor 21 d is electrically connected to the control device 40 and its drive is controlled by the control device 40 . The position detector 21e is a device such as an encoder, and is attached to the motor 21d. This position detector 21 e is electrically connected to the control device 40 and transmits a detection signal to the control device 40 . The transport unit 21 runs the transport belt 21a together with the driven pulleys 21c by rotating the drive pulley 21b by the motor 21d, and transports the tablets T on the transport belt 21a in the transport direction A1 (clockwise direction).

As shown in FIG. 2, a plurality of circular suction holes 21g are formed in the conveying belt 21a. These suction holes 21g are through holes for sucking tablets T, and are arranged in a line along the transport direction A1 so as to form a single transport path. Each suction hole 21g is connected to the inside of the suction chamber 21f via a suction path (not shown) formed in the suction chamber 21f (see FIG. 1), so that a suction force can be obtained by the suction chamber 21f. It's becoming A pump is connected to the suction chamber 21f via a suction pipe (both not shown), and the pressure in the suction chamber 21f is reduced by the operation of the pump. The suction pipe is connected to substantially the center of the side surface (surface parallel to the transport direction A1) of the suction chamber 21f. Also, the pump is electrically connected to the control device 40 and its driving is controlled by the control device 40 . When the suction chamber 21f is decompressed, the tablets T placed on the suction holes 21g of the conveyor belt 21a are sucked by the suction holes 21g and held on the conveyor belt 21a.

The detection unit 22 is positioned downstream in the transport direction A1 from the position where the supply device 10 is provided, and is provided above the transport path formed by the suction holes 21g. The detection unit 22 detects the position of the tablet T in the X direction (see FIG. 2) of the tablet T on the conveyor belt 21a that has reached the detection position directly below the detection unit 22 (the arrival of the tablet T). to detect Further, the detection unit 22 detects the height of the tablets T on the conveying belt 21a. For example, a displacement sensor is used as the detection unit 22 . Various laser sensors such as a reflective laser sensor are used as the displacement sensor. The detector 22 is electrically connected to the control device 40 and transmits a detection signal to the control device 40 .

The first imaging unit 23 is positioned downstream in the transport direction A1 from the position where the detection unit 22 is provided, and is provided above the transport path formed by the suction holes 21g. Based on the position information of the tablet T in the X direction detected by the detection unit 22, the first imaging unit 23 detects the position of the tablet T at the first imaging timing when the tablet T reaches the imaging position directly below the first imaging unit 23. An image is captured to acquire a first image including the upper surface of the tablet T, and the acquired first image is transmitted to the control device 40 . The first image is used to detect the positions of the tablet T in the X direction, Y direction, and θ direction (see FIG. 2). is used to detect As the first imaging unit 23, various cameras having imaging elements such as CCD (charge-coupled device) and CMOS (complementary metal oxide semiconductor) are used. The first imaging section 23 is electrically connected to the control device 40 and its drive is controlled by the control device 40 . In addition, illumination for imaging is also provided as needed.

Here, the positions of the tablet T in the X direction and the Y direction are, for example, the positions of the XY coordinate system with respect to the center (reference position) of the imaging area of the first imaging unit 23 . Further, the position in the θ direction is, for example, the position indicating the degree of rotation of the tablet T within 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 the tablet T is provided with a dividing line, or when the tablet T is formed in an elliptical, oval, square, or the like shape. be done. Note that the X and Y directions are positions in the horizontal direction.

The inkjet head 24 is positioned downstream in the transport direction A1 from the position where the first imaging unit 23 is provided, and is provided above the transport path formed by the suction holes 21g. The inkjet head 24 has a plurality (for example, several hundred to several thousand) of nozzles 24a (see FIG. 2), and the direction in which the nozzles 24a are arranged in a row (nozzle row) is perpendicular to (intersects) the transport direction A1 in the horizontal plane. example). The inkjet head 24 ejects ink individually from each nozzle 24a by operating a driving element for each nozzle 24a. As the inkjet head 24, various inkjet print heads having drive elements such as piezoelectric elements, heating elements, magnetostrictive elements, etc. are used. The inkjet head 24 is electrically connected to the control device 40 and its drive is controlled by the control device 40 .

The second imaging unit 25 is positioned downstream in the transport direction A1 from the position where the inkjet head 24 is provided, and is provided above the transport path formed by the suction holes 21g. Based on the X-direction position information of the tablet T detected by the detection unit 22, the second imaging unit 25 detects the position of the tablet T at the second imaging timing when the tablet T reaches the imaging position directly below the second imaging unit 25. An image is captured to acquire a second image including the upper surface of the tablet T, and the acquired second image is transmitted to the control device 40 . The second image is used to inspect the print pattern printed on the tablet T. FIG. As the second imaging section 25, various cameras having an imaging device such as a CCD or a CMOS, for example, are used in the same manner as the first imaging section 23 described above. The second imaging section 25 is electrically connected to the control device 40 and its driving is controlled by the control device 40 . Illumination for imaging is also provided as needed.

The moving mechanism 26 moves the inkjet head 24 in the vertical direction (vertical direction in FIG. 1). The moving mechanism 26 is provided at a position adjacent to the conveying belt 21a and the suction chamber 21f (on the back side of FIG. 1 and on the upper side of FIG. 2) while avoiding the conveying belt 21a and the suction chamber 21f. The ink jet head 24 is opposed to and held by the transport surface of . The conveying surface of the conveying belt 21a is the surface on which the tablets T are placed on the conveying belt 21a, and is the surface of the conveying belt 21a on the inkjet head 24 side. The moving mechanism 26 can move the inkjet head 24 up and down to change the distance between the transport surface of the transport belt 21 a and the ejection surface of the inkjet head 24 . The ejection surface of the inkjet head 24 is the surface on which the nozzles 24a are formed in the inkjet head 24, and is the surface of the inkjet head 24 on the conveying belt 21a side. A linear guide mechanism, for example, is used as the moving mechanism 26 . The moving mechanism 26 is electrically connected to the control device 40 and its drive is controlled by the control device 40 .

The drying section 27 is arranged at a position facing the conveying belt 21a, and is provided below the conveying section 21, for example. The drying section 27 dries the ink applied to each tablet T on the conveyor belt 21a. As the drying unit 27, various dryers are used, such as a blower that dries with gas such as air, a heater that dries with radiant heat, or a blower that dries with warm air or hot air using both gas and a heater. be done. The drying section 27 is electrically connected to the control device 40 and its drive is controlled by the control device 40 .

The collection device 30 is positioned downstream in the transport direction A1 from the position where the drying section 27 is provided, and is provided below the transport section 21 . This recovery device 30 has a reuse product recovery unit 31 , a defective product recovery unit 32 , and a non-defective product recovery unit 33 . In the recovery device 30 , the reused product recovery unit 31 recovers the recycled tablets T, the defective product recovery unit 32 recovers the defective tablets T, and the non-defective product recovery unit 33 recovers the non-defective tablets T. For example, the reusable product is a reusable tablet, a non-printed tablet that is intact and free of foreign matter. In addition, defective products include non-printed tablets with foreign matter attached and unacceptable printed tablets (printed tablets) that are not damaged and have no foreign matter attached. be. The order of arrangement in the conveying direction A1 of the reusable product recovery unit 31, the defective product recovery unit 32, and the non-defective product recovery unit 33 is not limited to the order shown in FIG. 1, and may be changed as appropriate. The recovery device 30 is electrically connected to the control device 40 and its driving is controlled by the control device 40 .

The reusable product recovery section 31 has an injection nozzle 31a and a recovery box 31b. In addition, the defective product recovery section 32 has an injection nozzle 32a and a recovery box 32b. The non-defective product recovery section 33 has an injection nozzle 33a and a recovery box 33b. These injection nozzles 31a, 32a, 33a have basically the same structure, and the collection boxes 31b, 32b, 33b also have basically the same structure. Therefore, the injection nozzle 31a and the collection box 31b will be described as representatives.

The injection nozzle 31a and the collection box 31b are provided at positions facing each other across a conveying path along which the suction holes 21g of the conveying belt 21a line up. The jet nozzle 31a is arranged in the suction chamber 21f, and jets gas (for example, air) toward the conveyor belt 21a to drop the tablets T from the conveyor belt 21a. At this time, the gas injected from the injection nozzle 31a hits the tablets T through the suction holes 21g of the conveyor belt 21a. The injection nozzle 31a is electrically connected to the control device 40, and its drive is controlled by the control device 40. FIG. The recovery box 31b is provided below the conveying section 21 directly below the injection nozzle 31a. The collection box 31b receives and stores the tablets T dropped from the conveying belt 21a by the gas jetted from the jet nozzle 31a.

Here, the tablets T that have passed through the reuse product recovery unit 31 and the defective product recovery unit 32 are transported as the transport belt 21a moves, and reach a position near the end of the transport belt 21a on the driven pulley 21c side. do. At this position, the suction action does not work on the tablets T, but the jet nozzle 33a blows air onto the tablets T from above, and the tablets T drop from the conveying belt 21a. Therefore, by providing the injection nozzle 33a, the tablets T can be reliably dropped from the conveying belt 21a. The recovery box 33b receives and stores the tablets T dropped from the conveying belt 21a by the gas ejected from the ejection nozzle 33a.

The control device 40 controls each part of the tablet printing device 1, such as the feeding device 10, the printing device 20, the collection device 30, etc., based on various information and various programs. Further, the control device 40 receives detection information (for example, a detection signal) transmitted from the position detector 21e of the conveying unit 21 and the detection unit 22, respectively, and also receives detection information from the first imaging unit 23 and the second imaging unit. 25 receives image information and the like transmitted from 25. The control device 40 is implemented by, for example, an electronic circuit such as an integrated circuit or a computer.

(Configuration example of control device)
Next, a configuration example of the control device 40 will be described with reference to FIG.

As shown in FIG. 3 , the control device 40 has an image processing section 41 , a storage section 42 and a control section 43 . An input device 40 a and an output device 40 b are connected to the control device 40 . The input device 40a is implemented by, for example, a switch, touch panel, keyboard, mouse, or the like. Also, the output device 40b is implemented by, for example, a display, a lamp, a meter, or the like.

The image processing unit 41 takes in the first image captured by the first imaging unit 23 and the second image captured by the second imaging unit 25, and processes the images using a known image processing technique. . For example, the image processing unit 41 processes the first image obtained from the first imaging unit 23, acquires the presence or absence of damage to the tablet T and adhesion of foreign matter, and furthermore, determines whether the tablet T is damaged in the X direction, the Y direction, and the Get the position in the θ direction. Further, the image processing unit 41 processes the second image obtained from the second imaging unit 25, and obtains the printing position, shape, and size of the printing pattern (for example, characters and marks) printed on the tablet T. do. The image processing unit 41 obtains the acquired information on the presence or absence of damage or adherence of foreign matter to the tablet T, the acquired positional information of each tablet T in the X direction, the Y direction and the θ direction, and the print position information of the print pattern on each tablet T. , shape information and size information to the control unit 43 .

The storage unit 42 stores processing information, various programs, and the like. For example, it is realized by a semiconductor memory device 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 42 stores print data related to printing, moving speed data of the conveying belt 21a, and the like. The print data includes print pattern information such as characters and marks.

The control unit 43 is, for example, a computer such as a CPU (Central Processing Unit), MCU (Micro Control Unit), MPU (Micro Processing Unit), etc., and controls each unit. For example, the control unit 43 controls the supply device 10, the printing device 20, the collecting device 30, the image processing unit 41, the storage unit 42, etc. based on various information and various programs stored in the storage unit 42. FIG. The control unit 43 also receives detection signals and the like transmitted from the position detector 21e of the transport unit 21 and the detection unit 22, respectively. Note that the control unit 43 is realized by one or both of hardware and software, for example.

For example, the control unit 43 determines whether the height of the tablet T on the conveying belt 21a is abnormal based on the height information regarding the height of the tablet T detected by the detection unit 22 . For example, when the height of the tablet T exceeds a predetermined threshold value, the control unit 43 determines that the height of the tablet T on the conveyor belt 21a is abnormal. A tablet with an abnormal height (hereinafter also referred to as an “abnormal height tablet”) T is, for example, a tablet in an upright posture. The tablet T in the standing posture is in a state in which the posture of the tablet T is vertical or inclined with respect to the transport surface of the transport belt 21a. As it moves forward, it collides with the inkjet head 24 whose ejection surface is positioned at a predetermined normal position H1 (see FIG. 4). The tablet T may be held on the conveyor belt 21a in an upright posture by the suction action of the suction holes 21g. In particular, when the surface of the tablet T to be held has an R shape, a single point other than the central portion of the tablet T may be the area to be sucked, and the tablet T may be held in an upright posture.

Further, the control unit 43 changes the transport speed at which the transport belt 21a transports the tablets T based on whether the height of the tablets T on the transport belt 21a is abnormal, and also changes the transport surface of the transport belt 21a. and the ejection surface of the inkjet head 24 are changed. For example, when the height of the tablets T on the conveying belt 21a is abnormal, the control unit 43 controls the conveying unit 21 so as to reduce the conveying speed of the conveying belt 21a. The moving mechanism 26 is controlled so as to widen the distance from the ejection surface. After that, when the tablet T having an abnormal height passes directly under the inkjet head 24, the control unit 43 controls the moving mechanism 26 so as to return the inkjet head 24 to the normal position H1, thereby conveying the conveying belt 21a. The conveying unit 21 is controlled so as to restore the original speed.

More specifically, as shown in FIG. 4, the control unit 43 causes the inkjet head 24 to rise and the ejection surface of the inkjet head 24 to move to a predetermined normal position H1 with respect to the tablet T whose height is abnormal. to a predetermined retracted position H2. As a result, the distance between the conveying surface of the conveying belt 21a and the ejection surface of the inkjet head 24 is widened. Even if the tablet T whose height is abnormal reaches directly under the inkjet head 24 whose ejection surface is positioned at the predetermined retreat position H2 by the conveying belt 21a in that state, it collides with the inkjet head 24.例文帳に追加It passes directly under the inkjet head 24 without any movement. After that, at the timing when the tablet T whose height is abnormal passes directly under the inkjet head 24, the inkjet head 24 descends and the ejection surface of the inkjet head 24 moves from the predetermined retracted position H2 to the predetermined normal position H1. Control the moving mechanism 26 to move. As a result, the distance between the conveying surface of the conveying belt 21a and the ejection surface of the inkjet head 24 is restored.

Here, the predetermined threshold value, the predetermined normal position H1, the predetermined retraction position H2, etc. are usually set in advance and stored in the storage unit 42, for example. However, the predetermined threshold value, the predetermined normal position H1, the predetermined retracted position H2, etc. may be changed according to predetermined conditions, or may be changed according to the user's input operation on the input device 40a. For the predetermined threshold value, for example, a value of the thickness of the tablet T+1 mm is set. The distance between the printing surface of the tablet T and the ejection surface of the inkjet head 24 is usually about 1 mm, and the thickness of the tablet T is about 2 to 8 mm. When the height of the tablet T exceeds 4 mm, the threshold value is exceeded, and the tablet T is determined to be abnormal in height, and collision of the tablet T with the inkjet head 24 can be prevented. The predetermined normal position H1 is, for example, a position where the ink-jet head 24 does not collide with the tablets T in a lying state (normal posture) on the conveyor belt 21a and can normally print on the tablets T on the conveyor belt 21a. (For example, a height position 1 mm away from the printing surface of the tablet T) is determined experimentally or theoretically and set. In addition, the predetermined retreat position H2 is a position where the inkjet head 24 does not contact the tablet T whose height above the conveying belt 21a is abnormal (for example, a height away from the conveying belt 21a by at least the major diameter of the tablet T). position). Note that a proper margin is taken for both positions.

Further, the control unit 43 acquires the position of the tablet T in the X direction on the transport belt 21a based on the detection information transmitted from the detection unit 22, that is, the timing at which the tablet T on the transport belt 21a is detected, and detects the position of the tablet T on the transport belt 21a. Based on the position information indicating the position of T in the X direction, 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 are set, Timing information indicating these timings is generated and stored in the storage unit 42 . The timing to start printing is the timing to start printing on the tablet T that has reached the printing position directly below the inkjet head 24 . Note that the control unit 43 can acquire information such as the movement amount (rotation amount) and speed of the conveying belt 21a based on the detection information transmitted from the position detector 21e.

Further, the control unit 43 obtains information on the presence/absence of damage or adhesion of foreign matter to the tablet T transmitted from the image processing unit 41 (this information is based on the first image). Whether or not printing is permitted for the tablet T is set as printability information. Then, the control unit 43 sets the printing condition as the printing condition information for the tablet T set to be printable. At this time, based on the positional information of the tablet T in the X direction, the Y direction, and the θ direction transmitted from the image processing unit 41, the control unit 43 sets the printing conditions for the tablet T for which the positional information is obtained. do. For example, the control unit 43 determines the range of the nozzles 24a to be used for printing the target tablet T in the inkjet head 24, i.e., the range of nozzles to be used, based on the positional information of the tablet T in the Y direction and the print data. Set printing conditions including nozzle range and print start timing. When the tablet T has a directional shape, the control unit 43 sets the printing conditions corresponding to the position of the tablet T in the θ direction based on the positional information of the tablet T in the θ direction. As an example, the control unit 43 registers in the storage unit 42 180 different print patterns obtained by rotating the direction of the print pattern by 1 degree in the range of 0 degrees to 179 degrees. A printing pattern with an angle that matches the position of the tablet T in the θ direction is selected to set printing conditions.

In addition, the control unit 43 controls the printing position information, the shape information, and the size information (these information are based on the second image) of the printing pattern printed on the tablet T, which are transmitted from the image processing unit 41. Based on this, it is determined whether or not the print pattern was printed in a predetermined shape and size at a predetermined position on the tablet T, that is, whether or not the print pattern was normally printed on the tablet T, and the print quality information of the tablet T is set. (printing status inspection). For example, in determining the shape and size of the printed pattern, the control unit 43 registers a printed pattern for inspection in the storage unit 42, and stores the printed pattern for inspection and the actual printed pattern on the tablet T after printing ( The printed pattern printed on the tablet T).

Note that the control unit 43 appropriately controls various types of information (for example, information on the presence or absence of damage to the tablet T or adhesion of foreign matter, position information, height information on the tablet T, timing information, information on whether or not printing is possible, information on printing conditions, information on whether printing is good or bad, etc.). is stored in the storage unit 42, but when the target tablet T is collected by the collecting device 30, for example, it falls from the downstream end of the conveying unit 21 in the conveying direction A1 and a predetermined time (for example, several seconds) elapses. At that time, various information is deleted from the storage unit 42 . However, if such information is required in a post-process, etc., it is possible to leave the various information for each tablet T without erasing it, or to store it in a storage medium outside the device. be. When storing various types of information for each tablet T, this information is linked to the date of manufacture, lot number, etc., and stored so that it can be traced back in the event that a defective product occurs after shipment of the printed tablet T. It may also be possible to investigate the cause of the problem.

(Printing process)
Next, the printing process performed by the tablet printing apparatus 1 described above will be described with reference to FIG. The printing process also includes an inspection process. Various types of information such as data required for printing and data required for retracting the inkjet head 24 are stored in advance in the storage unit 42 .

As shown in FIG. 5, in step S1, when a large number of tablets T to be printed are loaded into the hopper 11 of the supply device 10, the tablets T start to be sequentially supplied from the hopper 11 to the alignment feeder 12, and the alignment feeder 12 feeds the tablets T in a row. lined up to move. In this example, the moving tablets T are sequentially supplied to the transfer belt 21a of the printing device 20 by the transfer feeder 13. FIG. The transport belt 21a is rotated in the transport direction A1 by the rotation of the driving pulley 21b and the driven pulleys 21c by the motor 21d. Therefore, the tablets T supplied onto the conveying belt 21a are arranged in a line on the conveying belt 21a and conveyed at a predetermined conveying speed.

In step S2, the tablets T on the conveyor belt 21a are detected by the detector 22. FIG. Specifically, the tablet T on the conveying belt 21a is detected by the detection unit 22 at the timing when it reaches the detection position (for example, the irradiation position of the laser beam) immediately below the detection unit 22, and the tablet T is detected at the timing when the tablet T is detected. Based on this, the controller 43 recognizes the position of the tablet T in the X direction on the conveyor belt 21a. Position information indicating the position of the tablet T in the X direction is generated by the control unit 43 and stored in the storage unit 42 . Further, the height of the tablet T on the conveying belt 21a is detected by the detection unit 22, the height information about the height of the tablet T is recognized by the control unit 43, and the height information of the tablet T is stored in the storage unit 42. Saved.

In step S3, it is determined whether or not the height of the tablets T on the conveyor belt 21a is abnormal based on the height information. For example, it is determined whether or not the height of the tablets T on the conveyor belt 21a exceeds a predetermined threshold. When it is determined that the height of the tablets T on the conveyor belt 21a exceeds the predetermined threshold, it is determined that the height of the tablets T on the conveyor belt 21a is abnormal (Yes in step S3), and the process proceeds to step S11. proceed to On the other hand, if it is determined that the height of the tablets T on the conveying belt 21a does not exceed the predetermined threshold value, it is determined that the height of the tablets T on the conveying belt 21a is normal (No in step S3), and processing is performed. goes to step S4.

In step S4, the first imaging unit 23 images the tablets T on the conveyor belt 21a. Specifically, the tablet T on the conveying belt 21a is imaged by the first imaging unit 23 at the first imaging timing when it reaches the imaging position directly below the first imaging unit 23, and the first imaging unit 23 A first image obtained by imaging is transmitted to the control device 40 . Based on this first image, the image processing unit 41 generates information on the presence/absence of damage to the tablet T and presence or absence of foreign matter, and positional information on the tablet T in the X direction, Y direction, and θ direction, and stores the information in the storage unit 42 . be done.

In step S5, the control unit 43 determines whether or not the target tablet T can be printed based on the information on whether the tablet T is damaged or adhered with foreign matter. If it is determined that the target tablet T can be printed (Yes in step S5), the process proceeds to step S6. Based on information such as the position information of the tablet T in the X direction, Y direction and θ direction and information such as the print pattern, the usable nozzle range and print start timing for the tablet T set to be printable (tablet T that is printable) are determined. The printing conditions including are set in the storage unit 42 . The ejection timing for the tablet T (timing for ejecting ink on the tablet T) is determined based on the print start timing (timing for starting printing on the tablet T). On the other hand, if it is determined that printing on the target tablet T is not possible (No in step S5), the process proceeds to step S9, and operations related to printing and inspection on the target tablet T are restricted. Note that the printability information of the tablet T is stored in the storage unit 42 as appropriate. Note that "restriction" of operations related to printing and inspection means at least not performing processing related to printing and inspection on the target tablet T. FIG.

In step S6, printing is performed by the inkjet head 24 based on the above printing conditions. In other words, the inkjet head 24 is controlled by the controller 43 so as to print a predetermined print pattern on the printable tablets T on the conveyor belt 21a. More specifically, the printable tablet T on the conveying belt 21a that has passed under the first imaging unit 23 is inkjet-printed based on the above-described printing conditions at the printing start timing when it reaches the printing position directly below the inkjet head 24. Printed by head 24 . In the inkjet head 24, ink is appropriately ejected from each nozzle 24a, and a print pattern (for example, numbers, alphabets, katakana, symbols, and graphics) is printed on the surface to be printed, which is the upper surface of the tablet T. FIG.

In step S7, the second imaging section 25 captures an image of the printed tablet T on the conveyor belt 21a. Specifically, the printed tablet T on the conveyor belt 21a is imaged by the second imaging unit 25 at the second imaging timing when it reaches the imaging position directly below the second imaging unit 25, and the second imaging is performed. A second image obtained by imaging by the unit 25 is transmitted to the control device 40 . This second image is processed by the image processing section 41 of the control device 40 . Specifically, the image processing unit 41 acquires information about the printed pattern printed on the tablet T, that is, the print position, shape, and size of the printed pattern. The second image transmitted from the second imaging unit 25 is processed by the image processing unit 41 to generate inspection information indicating the printing position, shape, and size of the print pattern already printed on the tablet T, and stored in the storage unit 42. Saved.

In step S8, the control unit 43 executes a printing condition inspection based on the above inspection information. Specifically, the control unit 43 determines whether or not the print pattern is normally printed on the tablet T based on the inspection information related to the printing position, shape, and size stored in the storage unit 42, and the tablet T is printed. Printing quality information indicating quality is generated and stored in the storage unit 42 . For example, in the print state inspection, the print pattern used for printing is stored in the storage unit 42 as the print pattern for inspection, and the non-defective product information about the predetermined print position, shape, and size of the print pattern for inspection and the storage unit 42 The stored inspection information about the print position, shape, and size of the actual printed print pattern is compared to determine whether the print pattern was normally printed on the tablet T (pass or fail).

In step S9, the recovery device 30 recovers the tablets T on the conveyor belt 21a. In addition, the ink applied to the tablet T is naturally dried during transportation, and is also dried by the drying section 27 . More specifically, when the reusable tablets T reach the reusable product collection unit 31 as the transport belt 21a moves, the jet nozzle 31a blows gas onto the tablets T from above, and the tablets T move to the transport belt. It falls from 21a and is accommodated by collection box 31b. Similarly, when the defective tablet T arrives at the defective product collection unit 32 as the transport belt 21a moves, the jet nozzle 32a blows air onto the tablet T from above, and the tablet T is ejected from the transport belt 21a. It drops and is received by the recovery box 32b. When the non-defective tablet T reaches a position near the end of the conveyor belt 21a on the side of each driven pulley 21c, the suction action stops working on the tablet T, and gas is blown onto the tablet T from above by the injection nozzle 33a. The tablets T drop from the conveyor belt 21a and are received by the collection box 32b. Such gas blowing control is performed by the control unit 43 based on various types of information such as tablet T position information, tablet T height information, print availability information, and print quality information.

In step S10, the control unit 43 determines whether or not printing has ended. For example, the number of printed tablets T is counted, and when the number reaches a predetermined production number, it is determined that printing is completed. If it is determined that printing has ended (Yes in step S10), the process ends. On the other hand, if it is determined that printing has not ended (No in step S10), the process returns to step S1. Regarding the determination of the end of printing, it may be determined that the printing has ended according to the user's input operation on the input device 40a, for example, according to the user's pressing of a print end button.

If it is determined in step S3 that the height of the tablets T on the conveyor belt 21a is abnormal (Yes in step S3), the controller 43 reduces the conveying speed of the conveyor belt 21a in step S11. For example, the conveying speed may be lowered gradually or stepwise at a constant rate from a predetermined normal speed, or may be lowered gradually or stepwise at a random rate. A predetermined normal speed is reduced to a predetermined speed, and it is desirable that this predetermined speed is a conveying speed about 1/10 of the normal speed.

For example, the predetermined speed is the distance between the position directly below the detection unit 22 and the position directly below the inkjet head 24 on the conveying belt 21a, It is determined based on the time it takes to travel. The distance between the position directly below the detection unit 22 and the position directly below the inkjet head 24 on the conveying belt 21a is, for example, the detection position where the tablets T on the conveying belt 21a are detected by the detecting unit 22 and the distance between the position directly below the inkjet head. 24 to the position immediately below the upstream end in the conveying direction A1.

In step S<b>12 , the inkjet head 24 is lifted by the moving mechanism 26 . For example, the inkjet head 24 rises until its ejection surface moves from a predetermined normal position H1 to a predetermined retracted position H2 (see FIG. 4). As a result, the distance between the conveying surface of the conveying belt 21a and the ejection surface of the inkjet head 24 is widened to a predetermined retraction interval. This predetermined retraction interval is such that even if the tablet T with an abnormal height reaches directly below the inkjet head 24 by the conveying belt 21a in that state, it does not collide with the inkjet head 24, and the tablet T does not collide with the inkjet head 24. is an interval that can pass directly under

In step S13, the control unit 43 restricts printing on a plurality of tablets T positioned before and after the tablet T whose height is abnormal, that is, the tablet T with abnormal height. For example, the inkjet head 24 is lifted by the moving mechanism 26 and stops discharging. As a result, the height-abnormal tablet T and the tablet T conveyed before and after it (that is, the tablet T passing directly under the inkjet head 24 when the inkjet head 24 is positioned at the retracted position H2) are will not be printed. As a result, it is possible to suppress the occurrence of tablets T with printing defects (printing failure).

In step S<b>14 , the controller 43 determines whether or not the height-abnormal tablet T has passed directly under the inkjet head 24 . If it is determined that the height-abnormal tablet T has passed directly under the inkjet head 24 (Yes in step S14), the process proceeds to step S15. For example, the control unit 43 determines that the height-abnormal tablet T has passed directly below the inkjet head 24 when a predetermined time has passed since the detecting unit 22 detected the tablet T on the conveying belt 21a. Whether or not the height-abnormal tablet T has passed directly under the inkjet head 24 may be detected by the position detector 22e.

For example, the predetermined time is the transport speed of the tablet T (variable transport speed), the distance between the position directly below the detection unit 22 and the position directly below the inkjet head 24 on the transport belt 21a, and the movement of the transport belt 21a. It is determined based on the amount (rotation amount). The distance between the position directly below the detection unit 22 and the position directly below the inkjet head 24 on the conveying belt 21a is, for example, the detection position where the tablets T on the conveying belt 21a are detected by the detecting unit 22. It is the distance from the position immediately below the downstream end of the inkjet head 24 in the transport direction A1.

In step S<b>15 , the inkjet head 24 is lowered by the moving mechanism 26 . For example, the inkjet head 24 descends until the ejection surface moves from the predetermined retracted position H2 to the predetermined normal position H1 (see FIG. 4). As a result, the distance between the conveying surface of the conveying belt 21a and the ejection surface of the inkjet head 24 returns to a predetermined normal distance (the distance when the inkjet head 24 is positioned at the normal position H1).

In step S16, the conveying speed of the conveying belt 21a is restored by the control section 43, and the process proceeds to step S9. For example, the conveying speed may be gradually or stepwise increased at a constant rate to a predetermined normal speed, or may be gradually or stepwise increased at a random rate. Note that the predetermined normal speed is set in advance and stored in the storage unit 42, for example. However, the predetermined normal speed may be changed according to a predetermined condition, or may be changed according to the user's input operation on the input device 40a.

According to such a printing process, the control unit 43 reduces the conveying speed of the conveying belt 21a in response to the detection of height abnormality by the detecting unit 22, The distance between the belt 21a and the surface of the inkjet head 24 is widened. As a result, the tablet T having an abnormal height on the conveying belt 21a can pass through the inkjet head 24 without colliding with it. Therefore, since it is possible to suppress damage to the ink jet head 24 and breakage of the tablet T, adverse effects such as an increase in the number of times of maintenance, extension of maintenance time, and breakage of the tablet T are suppressed, and the tablet T is efficiently printed. be able to.

Further, in response to the detection of the height abnormality, the control unit 43 reduces the conveying speed of the conveying belt 21a to prevent the tablet T with the abnormal height from reaching directly below the inkjet head 24. Printing by the head 24 may be continued. In other words, the inkjet head 24 stays at the normal position H1 and continues printing until it prints on the tablet T positioned one downstream (in the transport direction A1) of the height-abnormal tablet T. FIG. The conveying speed of the conveying belt 21a from the detection of the height-abnormal tablet T until the tablet T positioned one downstream of the height-abnormal tablet T reaches directly below the inkjet head 24 is the conveying belt The speed of the inkjet head 24 is reduced to a speed at which the inkjet head 24 can move from the normal position H1 to the retracted position H2 in the time required for the transport belt 21a to move for the distance between the tablets transported on the tablet 21a. The control unit 43 corrects the ejection timing of the inkjet head 24 so as to match the conveying speed of the conveying belt 21a during this period, and continues printing on the tablet T. FIG.

The control unit 43 raises the inkjet head 24, and as soon as the tablet T whose height is abnormal passes directly under the inkjet head 24, returns the inkjet head 24 to the original height position (normal position H1) and transports it. The conveying speed of the belt 21a is returned to the normal speed, and printing is resumed at the normal conveying speed. Printing by the inkjet head 24 is interrupted only during the upward movement of the inkjet head 24, the passage of the height-abnormal tablet T below the inkjet head 24, and the downward movement of the inkjet head 24. When the inkjet head 24 is at the normal position H1, printing is performed, the tablet T can be printed efficiently. That is, although the tablets following the height-abnormal tablet T existing at a distance corresponding to the length in the conveying direction A1 of the inkjet head 24 cannot be printed, the height-abnormal tablet T is located in the conveying direction of the inkjet head 24. After passing the downstream end of A1, printing can be resumed, and tablets T that become non-printable tablets due to the abnormal height tablets T being conveyed can be suppressed as much as possible. Note that the processing related to printing and inspection is also restricted for the tablets T succeeding the height-abnormal tablet T, and these tablets T are also non-printable tablets.

Here, normally, the feeding speed at which the tablets T are fed from the feeding device 10 to the conveying unit 21 (the conveying speed at which the feeders such as the alignment feeder 12 and the delivery feeder 13 convey the tablets T) is always the same as the conveying belt 21a. is set slower than the transport speed for transporting the Therefore, when the conveying speed of the conveying belt 21a is reduced so as to maintain a predetermined speed difference between the feeding speed of the feeding device 10 and the conveying speed of the conveying belt 21a, the control unit 43 causes the feeding device 10 to The speed may also be reduced. As a result, clogging of the tablets T in feeders such as the alignment feeder 12 and the delivery feeder 13 can be suppressed.

Further, the control unit 43 may control the feeding device 10 so as to stop feeding new tablets T as soon as a tablet T having an abnormal height is detected. As a result, new tablets T are not supplied onto the conveyor belt 21a in response to occurrence of a tablet T having an abnormal height. A maintenance mechanism (not shown) for the inkjet head 24 enters between the inkjet head 24 and the conveyor belt 21a to perform maintenance. At this time, the inkjet head 24 may retreat to a position higher than the normal position H1 in order to create a space for the maintenance mechanism to enter. Therefore, as soon as the tablets T on the transport belt 21a are collected, maintenance work of the inkjet head 24 can be performed when new tablets T are not supplied to the transport belt 21a. Further, the maintenance of the conveying belt 21a (and the suction holes 21g) may be performed at the same time as the maintenance of the inkjet head 24 is performed.

In addition, the control unit 43 restricts the ejection of ink from the inkjet head 24 to the tablets T that have passed directly below the detection unit 22 during the period in which the conveying speed of the conveying belt 21a is reduced, and the period in which the conveying speed of the conveying belt 21a is reduced. Alternatively, the recovery device 30 may be controlled so that the tablet T that has passed directly under the detection unit 22 is recovered as a reusable non-printed tablet, that is, a reusable product. As a result, the tablets T that have passed directly under the detection unit 22 during the period in which the conveying speed of the conveying belt 21a is lowered can be collected as reusable products.

In addition, the inkjet head 24 is moved by the moving mechanism 26 in order to change the distance between the mounting surface of the transport belt 21a and the ejection surface of the inkjet head 24. However, the transport belt 21a is not limited to this. It may be moved by the moving mechanism 26 . The movement of the transport belt 21a may be realized by moving the entire transport unit 21 by the moving mechanism 26, or by moving part of the transport belt 21a facing the inkjet head 24 by the moving mechanism 26. may be implemented with

Here, when the object to be conveyed is a tablet T, for example, compared to the case where the object to be conveyed is paper, the speed at which it passes under the inkjet head 24 is orders of magnitude faster. and the ink jet head 24, and the distance between the objects to be conveyed is narrow. Therefore, it is not enough to simply prevent the collision between the object to be conveyed and the inkjet head 24, but it is necessary to prevent the collision and retract the inkjet head 24 in order to prevent the collision. It is important to find ways to reduce the number as much as possible. Further, if the operation of the entire apparatus is stopped due to the detection of a tablet T having an abnormal height, and the tablet T on the conveying belt 21a is collected while it is not printed (non-printed tablet), the productivity drops significantly. Resulting in. Therefore, according to the present embodiment as described above, it is possible to solve problems unique to tablets that are not found in printing on paper. When printing on tablets T, unlike when printing on paper, a single inkjet head 24 may be used to print a plurality of tablets T arranged horizontally and perpendicularly to the transport direction. .

As described above, according to the first embodiment, the tablet printing apparatus 1 includes the transport unit 21 that transports the tablets T by the transport belt 21a and the detection unit 22 that detects the tablets T transported by the transport belt 21a. The distance between the inkjet head 24 that ejects ink onto the tablet T detected by the detection unit 22 and the surface of the inkjet head 24 on the side of the conveyor belt 21a and the surface of the conveyor belt 21a on the side of the inkjet head 24 is changed. a moving mechanism 26 for moving the conveying belt 21a or the inkjet head 24, and a control unit 43 for controlling the conveying unit 21 and the moving mechanism 26. The detecting unit 22 detects height information of the tablets T on the conveying belt 21a. Based on the height information, when the height of the tablet T exceeds a predetermined threshold value, the control unit 43 controls the conveying unit 21 so as to reduce the conveying speed of the conveying belt 21a, and reduces the interval. The moving mechanism 26 is controlled to spread. As a result, when the height of the tablet T exceeds a predetermined threshold value, the conveying speed of the conveying belt 21a is reduced, and the surface of the conveying belt 21a side of the inkjet head 24 and the surface of the conveying belt 21a facing the inkjet head 24 are reduced. is widened, it is possible to suppress collision of the tablets T with an abnormal height on the conveying belt 21a against the inkjet head 24.例文帳に追加Therefore, since it is possible to suppress damage to the ink jet head 24 and breakage of the tablet T, adverse effects such as an increase in the number of times of maintenance, extension of maintenance time, and breakage of the tablet T are suppressed, and the tablet T is efficiently printed. be able to.

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

As shown in FIG. 6, the tablet printing device 2 according to the second embodiment is a device capable of printing on both sides of the tablet T, and includes the feeding device 10 according to the first embodiment, the first printing device 20, In addition to the collecting device 30 and the control device 40, a second printing device 50 is provided. Unlike the first embodiment, the collection device 30 is provided not for the first printing device 20 but for the second printing device 50 .

The first printing device 20 and the second printing device 50 are arranged one above the other, and the tablet T printed by the first printing device 20 on the upper side is reversed and printed by the second printing device on the lower side. 50 where both sides of the tablet T are printed. Normally, the conveying speed of the first printing device 20 and the conveying speed of the second printing device 50 are always the same in order to smoothly transfer the tablets T from the first printing device 20 to the second printing device 50. . Therefore, when one of the conveying speeds is changed by the controller 43, the other conveying speed is also changed by the controller 43 accordingly.

The second printing device 50 has the same structure as the first printing device 20 . Specifically, the second printing device 50 includes a conveying section 51 , a detecting section 52 , a first imaging section 53 , an inkjet head 54 , a second imaging section 55 , a moving mechanism 56 and a drying section 57 . The transport section 51 also includes a transport belt 51a, a drive pulley 51b, a plurality of driven pulleys 51c, a motor 51d, a position detector 51e, and a suction chamber 51f. The transport unit 51 transports the tablets T on the transport belt 51a in the transport direction A2 (counterclockwise direction). Since each element constituting the second printing apparatus 50 has basically the same structure as each element constituting the first printing apparatus 20, the description thereof will be omitted.

Here, when a tablet T with an abnormal height is transferred from the first printing device 20 to the second printing device 50, the state does not change and the tablet T on the conveying belt 51a of the second printing device 50 does not change. However, the height is often in an abnormal state, but depending on the situation, the state may change and, for example, may lie on the conveying belt 51a of the second printing device 50 . Therefore, an example (first processing example and second processing example) in which both the first printing device 20 and the second printing device 50 detect an abnormality in the height of the tablet T, and the first printing device An example (third processing example) in which the abnormal height of the tablet T is detected only in the printer 20 and the detection result is also used in the second printer 50 will be described below.

(First processing example)
In the first processing example, when the detection unit 22 of the first printing device 20 detects an abnormality in the height of the tablets T on the conveying belt 21a, the control unit 43 controls the conveying belt 21a of the first printing device 20. and the conveying speed of the conveying belt 51a of the second printing device 50 are reduced, and the tablet T with an abnormal height reaches immediately below the inkjet head 24 of the first printing device 20. Printing by the inkjet head 24 is continued. The control unit 43 raises the inkjet head 24 of the first printing device 20 to the retracted position H2, and moves the inkjet head 24 to the normal position H1 as soon as the tablet T having an abnormal height passes directly below the inkjet head 24. , the conveying speed of the conveying belt 21a of the first printing device 20 and the conveying speed of the conveying belt 51a of the second printing device 50 are returned to the normal speed, and printing is resumed. The flow of this process is the same as steps S11 to S16 shown in FIG. Printing by the inkjet head 54 of the second printing device 50 is continued during the upward movement of the inkjet head 24, the downward passage of the abnormal height tablet T through the inkjet head 24, and the downward movement of the inkjet head 24. FIG. Therefore, the tablet T can be printed efficiently. Although the first printer 20 restricts printing on the tablet T whose height is abnormal, the second printer 50 also continues to restrict printing on the tablet T. FIG.

Similarly, when the detection unit 52 of the second printing device 50 detects an abnormal height of the tablets T on the conveying belt 51a, the control unit 43 reduces the conveying speeds of the conveying belts 21a and 51a to increase the height. Printing by the inkjet head 54 of the second printing device 50 is continued until immediately before the tablet T whose height is abnormal reaches directly below the inkjet head 54 of the second printing device 50 . The control unit 43 raises the inkjet head 54 of the second printing device 50 to the retracted position H2, and as soon as the tablet T whose height is abnormal passes directly below the inkjet head 54, the inkjet head 54 is moved to the normal position H1. , the conveying speed of the conveying belt 21a of the first printing device 20 and the conveying speed of the conveying belt 51a of the second printing device 50 are returned to the normal speed, and printing is resumed. The flow of this process is the same as steps S11 to S16 shown in FIG. Printing by the inkjet head 24 of the first printing device 20 continues during the upward movement of the inkjet head 54, the downward passage of the abnormal height tablet T through the inkjet head 54, and the downward movement of the inkjet head 54. FIG. Therefore, the tablet T can be printed efficiently.

As shown in FIG. 5, the specific processing flow according to the first processing example is as follows: Step S1 is executed, Steps S2 to S8 and S11 to S16 are executed in the first printer 20, Next, steps S2 to S8 and S11 to S16 are executed in the second printer 50, and then steps S9 to S10 are executed. That is, in the first processing example, both the first printing device 20 and the second printing device 50 detect the presence or absence of an abnormality in the height of the tablet T, and perform the same operations as in the first embodiment. process. In addition, as described above, in the first printing apparatus 20, when the plurality of tablets T including the tablet T whose height is abnormal (that is, when the inkjet heads 24 and 54 are positioned at the retracted position H2, 24 , 54 , but the printing restriction on the tablet T is continued even in the second printing device 50 . This also applies to the following second processing example and third processing example.

According to this first processing example, in the first printing device 20 and the second printing device 50, it is possible to suppress damage to the inkjet heads 24 and 54 and breakage of the tablets T. It is possible to efficiently print on the tablets T while suppressing adverse effects such as an increase in maintenance time, an increase in maintenance time, and breakage of the tablets T. Only during the time when the inkjet head 24 rises, the abnormal height tablet T passes below the inkjet head 24, and the inkjet head 24 descends, only the printing by the inkjet head 24 is interrupted, and the inkjet head 54 rises and the abnormal height tablet Printing by the inkjet head 54 is interrupted only during the downward passage of the inkjet head 54 in T and the descent of the inkjet head 54, and when the inkjet head 24 or the inkjet head 54 is at the normal position H1, either head can print. is performed, the tablet T can be printed efficiently.

(Second processing example)
The difference between the second processing example and the first processing example is that when the height abnormal tablet T is detected in the first printing device 20, the conveying speed of the conveying belts 21a and 51a is reduced, and then the height is increased. Until the abnormal tablet T passes below the inkjet head 54, the conveying speed of the conveying belts 21a and 51a is maintained to be lowered.

Here, in the first processing example, the speed at which the tablet T having an abnormal height is transferred from the first printing device 20 to the second printing device 50 is the normal speed. May not be passed properly. For example, the normal speed is the fastest possible speed at which the lying tablet T can be transferred from the first printing device 20 to the second printing device 50 without changing its position. Therefore, if the delivery of the tablet T with an abnormal height is executed at a normal speed, the delivery may be inappropriate and fail, for example. Specifically, the tablets T fall from the conveyor belt 21a or the conveyor belt 51a, and the tablets T that should be collected by the reusable product collection unit 31 are mixed with another collection device. It will fall to the bottom of 2 and be damaged. Therefore, when the detecting unit 22 of the first printing device 20 detects an abnormal height of the tablets T on the conveying belt 21a, the conveying speed of the conveying belt 21a of the first printing device 20 and the second printing device 50 A second processing example in which both the conveying speeds of the conveying belt 51a are maintained at a reduced state and the speed at which the tablets T are transferred from the first printing device 20 to the second printing device 50 is reduced will be described. .

In the second processing example, when the detection unit 22 of the first printing device 20 detects an abnormality in the height of the tablets T on the conveying belt 21a, the control unit 43 controls the conveying belt 21a of the first printing device 20. and the conveying speed of the conveying belt 51a of the second printing device 50 are reduced, and the tablet T with an abnormal height reaches immediately below the inkjet head 24 of the first printing device 20. Printing by the inkjet head 24 is continued. The control unit 43 raises the inkjet head 24 of the first printing device 20, and returns the inkjet head 24 to the original height position as soon as the tablet T whose height is abnormal passes directly under the inkjet head 24. , to resume printing. Printing by the inkjet head 54 of the second printing device 50 is continued during the upward movement of the inkjet head 24, the downward passage of the abnormal height tablet T through the inkjet head 24, and the downward movement of the inkjet head 24. FIG. Therefore, the tablet T can be printed efficiently.

After that, when the detecting unit 52 of the second printing device 50 detects that the height of the tablets T on the conveying belt 51a is abnormal, the conveying speed of the conveying belts 21a, 51a is maintained at a low speed. The unit 43 continues printing with the inkjet head 54 until immediately before the tablet T whose height is abnormal reaches directly below the inkjet head 54 of the second printing device 50 . The control unit 43 raises the inkjet head 54 of the second printing device 50, and returns the inkjet head 54 to the original height position as soon as the tablet T whose height is abnormal passes directly under the inkjet head 54. , the conveying speed of the conveying belt 21a of the first printing device 20 and the conveying speed of the conveying belt 51a of the second printing device 50 are returned to the normal speed, and printing is restarted. Printing by the inkjet head 24 of the first printing device 20 continues during the upward movement of the inkjet head 54, the downward passage of the abnormal height tablet T through the inkjet head 54, and the downward movement of the inkjet head 54. FIG. Therefore, the tablet T can be printed efficiently.

On the other hand, if the detection unit 52 of the second printing device 50 does not detect an abnormality in the height of the tablets T on the conveying belt 21a, the control unit 43 controls the conveying speed of the conveying belt 21a of the first printing device 20 and the second The conveying speed of the conveying belt 51a of the printing device 50 is returned to the normal speed. Note that the tablets T that could not be printed with the inkjet head 24 of the first printing device 20 are not printed with the inkjet head 54 of the second printing device 50, and the non-printing tablets, for example, can be reused. The used tablet T is recovered by the reusable product recovery unit 31 .

Further, when the height abnormality is not detected by the detection unit 22 of the first printing device 20 and the height abnormality is detected by the detection unit 52 of the second printing device 50, the control unit 43 performs the first printing. The conveying speed of the conveying belt 21a of the device 20 and the conveying speed of the conveying belt 51a of the second printing device 50 are lowered so that the tablet T having an abnormal height is directly below the inkjet head 54 of the second printing device 50. Printing by the inkjet head 54 is continued until just before reaching . The control unit 43 raises the inkjet head 54 of the second printing device 50, and returns the inkjet head 54 to the original height position as soon as the tablet T whose height is abnormal passes directly under the inkjet head 54. , the conveying speed of the conveying belt 21a of the first printing device 20 and the conveying speed of the conveying belt 51a of the second printing device 50 are returned to the normal speed, and printing by the inkjet head 54 is resumed. Printing by the inkjet head 24 of the first printing device 20 continues during the upward movement of the inkjet head 54, the downward passage of the abnormal height tablet T through the inkjet head 54, and the downward movement of the inkjet head 54. FIG. Therefore, the tablet T can be printed efficiently.

According to this second processing example, the same effects as those of the first processing example can be obtained. In addition, while the tablet T for which the height abnormality is detected by the detection unit 22 of the first printing device 20 is transferred from the first printing device 20 to the second printing device 50 at least, the first printing device 20 and the conveying speed of the conveying belt 51a of the second printing device 50 are maintained. This makes it possible to reduce the speed at which the tablets T are delivered from the first printing device 20 to the second printing device 50 . If the conveying speed at the time of delivery is lowered, one end of the height-abnormal tablet T positioned downstream in the conveying direction A1 is pushed by the first printer 20, and the other end is pushed by the second printer 50. It will be passed on gradually. This increases the possibility that the posture of the height-abnormal tablet T can be returned to the normal posture at the time of delivery from the first printing device 20 to the second printing device 50, compared to the delivery at the normal transport speed. Smooth delivery of the tablet T can be realized.

(Third processing example)
Here, since the tablet T whose height is abnormal in the first printer 20 often does not change even if it is transferred to the second printer 50, the second printer 20 In 50, it is assumed that the height of the tablet T is abnormal, and the detection unit 52 of the second printing device 50 may be set so as not to detect the height of the tablet T. In the case of such specifications, the height of the tablet T is detected only by the first printing device 20, and processing for the first printing device 20 and the second printing device 50 is performed according to the detected height. Execute. A third processing example in which the height of the tablet T is detected only by the first printing device 20 will be described.

In the third processing example, when the detection unit 22 of the first printing device 20 detects a height abnormality, the control unit 43 controls the transportation speed of the transportation belt 21a of the first printing device 20 and the second printing The conveying speed of the conveying belt 51a of the device 50 is lowered, and the printing by the inkjet head 24 of the first printing device 20 is continued until immediately before the tablet T whose height is abnormal reaches directly below the inkjet head 24 of the first printing device 20. do. The control unit 43 raises the inkjet head 24 of the first printing device 20, and returns the inkjet head 24 to the original height position as soon as the tablet T whose height is abnormal passes directly under the inkjet head 24. , to resume printing. Printing by the inkjet head 54 of the second printing device 50 is continued during the upward movement of the inkjet head 24, the downward passage of the abnormal height tablet T through the inkjet head 24, and the downward movement of the inkjet head 24. FIG. Therefore, the tablet T can be printed efficiently.

Here, the tablet T having an abnormal height in the first printing apparatus 20 is treated as a tablet having an abnormal height in the second printing apparatus 50 as well. Since the state may change when the sheet is transferred from the second printing apparatus 20 to the second printing apparatus 50, it is difficult to determine whether the height is abnormal on the conveying belt 51a of the second printing apparatus 50. Unknown tablets, ie tablets with unknown height.

The control unit 43 transfers the tablet T whose height is abnormal in the first printing device 20 from the first printing device 20 to the second printing device 50 , and controls the inkjet head of the second printing device 50 . Printing by the inkjet head 54 is continued until just before reaching directly under 54 . The control unit 43 raises the inkjet head 54 of the second printing device 50, and returns the inkjet head 54 to the original height position as soon as the tablet T whose height is abnormal passes directly under the inkjet head 54. , the conveying speed of the conveying belt 21a of the first printing device 20 and the conveying speed of the conveying belt 51a of the second printing device 50 are returned to the normal speed, and printing is restarted. Printing by the inkjet head 24 of the first printing device 20 continues during the upward movement of the inkjet head 54, the downward passage of the abnormal height tablet T through the inkjet head 54, and the downward movement of the inkjet head 54. FIG. Therefore, the tablet T can be printed efficiently.

According to this third processing example, the same effects as those of the first processing example can be obtained. Moreover, the tablet T for which the height abnormality is detected by the detection unit 22 of the first printing device 20 is transferred from the first printing device 20 to the second printing device 50, and at least the second printing device 50 The state in which the conveying speed of the conveying belt 21a of the first printing device 20 and the conveying speed of the conveying belt 51a of the second printing device 50 are lowered is maintained until they pass directly under the inkjet head 54 . As a result, the speed at which the tablet T is transferred from the first printing device 20 to the second printing device 50 can be reduced. can be returned to the normal posture, and smooth delivery of the tablet T from the first printing device 20 to the second printing device 50 can be realized.

As described above, according to the second embodiment, the same effects as those of the first embodiment can be obtained. That is, even when double-sided printing is performed on the tablet T as in the second embodiment, the tablet T can be printed efficiently as in the case of performing single-sided printing on the tablet T as in the first embodiment. .

<Other embodiments>
In the above description, the tablets T are printed using the tablet printing apparatuses 1 and 2 (tablet printing method) according to the embodiment. It is also possible to print on the tablet T using the tablet printing method) to manufacture the printed tablet T. That is, the tablet printing apparatuses 1 and 2 can be rephrased as a tablet manufacturing apparatus, and the tablet printing method can be rephrased as a tablet manufacturing method.

Further, in the above description, the tablet T is conveyed in a single row, but this is not a limitation, and the number of rows may be two or more, and is not particularly limited. However, the number of conveying belts 21a may be two or more, and is not particularly limited. Also, the number of inkjet heads 24 and 54 may be two or more, and is not particularly limited.

In the above description, the inkjet head 24 is a print head in which the nozzles 24a are arranged in a line, but the present invention is not limited to this. good. Alternatively, a plurality of inkjet heads 24 may be arranged in a horizontal plane in a direction perpendicular to the transport direction A1. The same applies to the inkjet head 54 as well.

In the above description, the inkjet head 24 is provided so that the direction in which the nozzles 24a are arranged is perpendicular to the transport direction A1 in the horizontal plane. may be provided so that the direction in which the are arranged is the direction intersecting the conveying direction A1 in the horizontal plane. The same applies to the inkjet head 54 as well.

Further, in the above description, the tablets T are supplied onto the conveyor belt 21a at random rather than at regular intervals, but the invention is not limited to this, and they 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 conveying belt 21a. Alternatively, it may be held and transported by its own weight on the transport belt 21a. The same applies to the conveying belt 51a.

In the above description, the conveying speed of the conveying belts 21a and 51a is gradually or stepwise reduced. When it is detected that the threshold value is exceeded, the transport speed may be rapidly reduced to the target transport speed. When returning the conveying speed of the conveying belts 21a and 51a from the reduced speed to the normal speed, the speed may be returned gradually, stepwise, or rapidly, as in the case of lowering. In any case, changing the conveying speed gradually or stepwise can prevent the tablets T from leaving the conveying belts 21a and 51a.

Further, in the above description, the control unit 43 determines whether or not the height of the tablet T is abnormal based on the height information regarding the height of the tablet T detected by the detection units 22 and 52. was exemplified, but it is not limited to this. For example, based on the image of the tablet T obtained by the first imaging unit 23, the area, length, and shape of the tablet T supplied to the conveying belts 21a and 51a when viewed from above are detected (indirectly, the tablet height information may be obtained by detecting the height of T). That is, it may be determined that the height of the tablet T is abnormal when the area or length of the tablet T in plan view is below a threshold value.

In the above description, when the height abnormal tablet T is detected by the detection units 22 and 52, the control unit 43 causes the inkjet heads 24 and 54 to move to the retracted position H2. , or up to a tablet T located one upstream side of the height-abnormal tablet T, but the present invention is not limited to this. For example, when the height abnormal tablet T is detected by the detectors 22 and 52, printing by the inkjet head 24 may be interrupted, and the normal position H1 may be moved to the retracted position H2. In this case, the conveying speed of the conveying belts 21a and 51a moves to the retracted position H2 during the period from when the height-abnormal tablet T is detected until the height-abnormal tablet T reaches the inkjet head 24 (54). It is sufficient to reduce the speed to a speed at which it is possible to do so. Alternatively, the inkjet heads 24 and 54 are adjusted so that the number of tablets T whose printing is restricted is several before and after the abnormal height tablet T (for example, about 10 tablets, or the time period when about 10 tablets are expected to be conveyed). It may be controlled to move to the retracted position H2. In this case, the speed difference before and after the conveying speed of the conveying belts 21a and 51a is reduced can be reduced, and the number of sheets printed per unit time can be increased.

Here, the above-mentioned tablet T can include tablets used for medicine, eating and drinking, cleaning, industrial use, or fragrance use. Tablets T include uncoated tablets (uncoated tablets), sugar-coated tablets, film-coated tablets, enteric-coated tablets, gelatin-coated tablets, multi-layer tablets, dry-coated tablets, etc. Various capsules such as hard capsules and soft capsules are also available. can be included in tablet T. Furthermore, the shape of the tablet T includes various shapes such as a disk shape, a lens shape, a triangular shape, and an elliptical shape. Moreover, when the tablet T to be printed is for medical use or food and beverage use, edible ink is suitable as the ink to be used. As the edible ink, synthetic pigment ink, natural pigment ink, dye ink, or pigment ink may be used.

Although several embodiments of the invention have been described above, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the scope of the invention described in the claims and equivalents thereof.

Reference Signs List 1 tablet printing device 2 tablet printing device 10 supply device 11 hopper 12 alignment feeder 13 delivery feeder 20 printing device 21 transport unit 21a transport belt 21b drive pulley 21c driven pulley 21d motor 21e position detector 21f suction chamber 21g suction hole 22 detector 23 First imaging unit 24 Ink jet head 24a Nozzle 25 Second imaging unit 26 Moving mechanism 27 Drying unit 30 Recovery device 31 Reused product recovery unit 31a Injection nozzle 31b Recovery box 32 Defective product recovery unit 32a Injection nozzle 32b Recovery box 33 Non-defective product Collection unit 33b Collection box 33a Injection nozzle 40 Control device 40a Input device 40b Output device 41 Image processing unit 42 Storage unit 43 Control unit 50 Printing device 51 Transport unit 51a Transport belt 51b Drive pulley 51c Driven pulley 51d Motor 51e Position detector 51f Suction Chamber 52 Detector 53 First imaging unit 54 Inkjet head 55 Second imaging unit 56 Moving mechanism 57 Drying unit A1 Conveyance direction A2 Conveyance direction H1 Normal position H2 Retreat position T Tablet

Claims (9)

a conveying unit for conveying tablets by a conveying belt;
a detection unit that detects tablets conveyed by the conveying belt;
an inkjet head that ejects ink onto the tablet detected by the detection unit;
a moving mechanism for moving the transport belt or the inkjet head so as to change the distance between the transport belt-side surface of the inkjet head and the inkjet head-side surface of the transport belt;
a control unit that controls the transport unit and the moving mechanism;
with
The detection unit detects height information of the tablets on the conveyor belt,
Based on the height information, when the height of the tablet exceeds a predetermined threshold, the control unit controls the conveying unit to reduce the conveying speed of the conveying belt and widen the interval. controlling the movement mechanism to
Tablet printing equipment. When the height of the tablet exceeds the predetermined threshold, the control unit limits ejection of ink from the inkjet head on the tablet whose height exceeds the predetermined threshold, and controls the height of the tablet. permitting the inkjet head to eject ink on the tablet having a density equal to or lower than the predetermined threshold;
The tablet printing apparatus according to claim 1. When the height of the tablet exceeds the predetermined threshold, the control unit reduces the conveying speed of the conveying belt so that the tablet whose height exceeds the predetermined threshold is transferred to the inkjet head. Allowing the inkjet head to eject ink for the tablet whose height is equal to or less than the predetermined threshold until reaching directly below
The tablet printing apparatus according to claim 2. When the tablet whose height exceeds the predetermined threshold passes directly under the inkjet head, the control unit controls the moving mechanism so as to restore the gap.
The tablet printing apparatus according to any one of claims 1 to 3. The control unit maintains the state in which the conveying speed is reduced until the interval is restored, and controls the conveying unit so as to return the conveying speed to the original state when the interval is restored.
The tablet printing apparatus according to claim 4. The control unit reduces the conveying speed to a predetermined speed,
The predetermined speed is the distance between the position directly below the detection unit and the position directly below the inkjet head on the conveying belt, and the speed at which the surface of the inkjet head on the conveying belt side moves from a predetermined normal position to a predetermined speed. determined based on the time it takes to move to the retracted position,
The tablet printing apparatus according to any one of claims 1 to 5. Further comprising a collection device for separating and collecting the tablets that have passed directly under the inkjet head into printed tablets to which ink has been applied and reusable non-printed tablets to which ink has not been applied,
The control unit limits the ink ejection of the inkjet head to the tablet that has passed directly under the detection unit during the period in which the conveying speed is reduced, and passes directly under the detection unit during the period in which the conveying speed is reduced. controlling the recovery device to recover the tablets as the non-printed tablets;
A tablet printing apparatus according to any one of claims 1 to 6. Further comprising a feeding device for feeding the tablets to the conveyor belt,
When the conveying speed is reduced, the control unit controls the feeding device so as to also reduce the tablet feeding speed.
A tablet printing apparatus according to any one of claims 1 to 7. the conveying unit conveying the tablets by means of a conveying belt;
a detection unit detecting the tablet conveyed by the conveying belt;
an inkjet head ejecting ink onto the tablet detected by the detection unit;
a moving mechanism moving the transport belt or the inkjet head so as to change the distance between the transport belt-side surface of the inkjet head and the inkjet head-side surface of the transport belt;
a control unit controlling the transport unit and the moving mechanism;
including
The detection unit detects height information of the tablets on the conveyor belt,
Based on the height information, when the height of the tablet exceeds a predetermined threshold, the control unit controls the conveying unit to reduce the conveying speed of the conveying belt and widen the interval. controlling the movement mechanism to
Tablet printing method.

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