JP6677483B2 - Tablet printing equipment - Google Patents

Description

  Embodiments of the present invention relate to a tablet printing apparatus.

  2. Description of the Related Art In order to print identification information such as characters and symbols on tablets, a technique of performing printing using an inkjet print head is known. A tablet printing apparatus using this technology conveys a plurality of tablets in a row by a conveyor, and sends ink (eg, ink) from a nozzle of an ink jet type print head arranged above the conveyor toward a tablet passing below the print head. Edible ink) and prints identification information on tablets on the conveyor.

  In this tablet printing apparatus, if air bubbles or dust are present in the flow path in the ink jet print head, they cause ejection failure. Further, when an ink that dries easily is used as the printing ink, the ink in the nozzle may increase in viscosity or a solid substance may be deposited, which causes ejection failure. The occurrence of such a discharge failure leads to a deterioration in print quality.

  Therefore, maintenance (dummy ejection or pressure feeding) for ejecting ink from the nozzles of the print head is periodically performed, and the print head is maintained in a normal state. Usually, whenever it is necessary to maintain the print head, it is necessary to stop transporting tablets. During the suspension period, printing on tablets is interrupted, and thus there is a problem that productivity is reduced. It is conceivable to improve productivity by transporting tablets in multiple rows, but there is still a similar problem.

JP-A-7-081050

  An object of the present invention is to provide a tablet printing apparatus capable of suppressing a decrease in productivity due to a stoppage of printing due to maintenance of a print head.

Tablet printing device according to an embodiment of the present invention,
Tablets are transported, at least two transport routes,
A maintenance unit provided between the two transport paths and performing maintenance;
An inkjet print head that is provided above the transport path and around the maintenance unit for each of the transport paths and that discharges liquid from a nozzle,
A moving device that individually moves the print heads to a print position above the transport path and a maintenance position above the maintenance unit, provided for each print head,
With
Between the maintenance position and the printing position, and the outlet hole so as to extend in the conveying direction before SL tablets from the printing head above is formed, a gas blowing part blowing gas downward from the outlet hole It is characterized by having.

  According to the embodiment of the present invention, it is possible to suppress a decrease in productivity due to a stoppage of printing due to maintenance of a print head.

1 is a diagram illustrating a schematic configuration of a tablet printing apparatus according to a first embodiment. FIG. 2 is a plan view illustrating a part of the tablet printing apparatus according to the first embodiment. FIG. 2 is an enlarged plan view illustrating a part of the tablet printing apparatus according to the first embodiment. It is a top view which expands and shows a part of tablet printing device concerning a 2nd embodiment. It is a top view which expands and shows a part of tablet printing device concerning a 3rd embodiment. It is a figure showing the schematic structure of the maintenance device concerning a 4th embodiment. It is a figure showing the schematic structure of the maintenance device concerning a 5th embodiment. It is a figure showing the schematic structure of the maintenance device concerning a 6th embodiment. It is a figure showing the schematic structure of the maintenance device concerning a 7th embodiment. It is a figure showing the schematic structure of the maintenance device concerning an 8th embodiment. It is a figure showing the schematic structure of the modification of the maintenance device concerning an 8th embodiment. It is a figure showing the schematic structure of the modification of the maintenance device concerning a 2nd embodiment.

(First embodiment)
A first embodiment of the present invention will be described with reference to FIGS.

(Basic configuration)
As shown in FIGS. 1 and 2, the tablet printing apparatus 1 according to the first embodiment includes a supply device 10, a transport device 20, a detection device 30, an imaging device 40, a printing device 50, and a collection device. 60, a maintenance device 70, an image processing device 80, and a control device 90.

  The supply device 10 includes a hopper 11 and a shooter 12. The hopper 11 stores a large number of tablets T, and sequentially supplies the stored tablets T to the shooter 12. The shooter 12 arranges the supplied tablets T in a plurality of rows and supplies the tablets T to the transport device 20. The supply device 10 is electrically connected to a control device 90, and its driving is controlled by the control device 90.

  The transport device 20 includes two transport belts 21 (see FIG. 2), a drive pulley 22, a driven pulley 23, and a drive unit 24. Each of the transport belts 21 is formed in an endless shape, and is stretched over a driving pulley 22 and a driven pulley 23 in parallel with each other. The driving pulley 22 and the driven pulley 23 are provided so as to be rotatable about an axis, and the driving pulley 22 is connected to a driving unit 24. The drive unit 24 is electrically connected to the control device 90, and its drive is controlled by the control device 90. The drive unit 24 includes a position detector 24a such as a rotary encoder. The position detector 24a transmits a detection signal to the control device 90. The control device 90 can obtain information such as the position, speed, and movement amount of each conveyor belt 21 based on the detection signal. Note that the transport device 20 has two transport paths with two transport belts 21.

  The transport device 20 rotates the transport belts 21 together with the driven pulleys 23 by the rotation of the drive pulleys 22 by the drive unit 24, and moves the tablets T on the transport belts 21 in the direction indicated by an arrow A1 in FIGS. Conveyed to A1). It should be noted that each of the conveyor belts 21 is formed such that straight slit-shaped suction ports 21a (see FIG. 2) are arranged in two rows along the transport direction A1. The two suction ports 21a are connected to a suction device (both not shown) via a suction chamber, and a suction force is obtained by driving a suction device (for example, a suction pump). The tablets T supplied on the suction port 21a are held on the transport belt 21 by suction of the suction port 21a.

  The detection device 30 includes a plurality of detection units 31 (see FIG. 2). The two detection units 31 are provided above the transport belt 21 for each of the transport belts 21. These detectors 31 are positioned downstream of the supply device 10 in the transport direction A1 and above the two rows of the suction ports 21a, and are arranged in a direction intersecting the transport direction A1 in a horizontal plane (for example, a direction orthogonal to the transport direction). Have been. Each detection unit 31 detects a tablet T on the transport belt 21 by emitting and receiving laser light. These detection units 31 are electrically connected to the control device 90 and transmit detection signals to the control device 90. As the detection unit 31, for example, various laser sensors (laser displacement meters) such as a reflection type laser sensor can be used. Further, as the beam shape of the laser light, various shapes such as spots and lines can be used.

  The imaging device 40 includes a plurality of imaging units 41 (see FIG. 2). Each of the imaging units 41 is provided above the transport belt 21 by two for each transport belt 21. These imaging units 41 are positioned downstream of the detection device 30 in the transport direction A1 and above the two rows of the suction ports 21a, and are arranged in a direction intersecting the transport direction A1 in a horizontal plane (for example, a direction orthogonal to the transport direction). Have been. The imaging field of view of the imaging unit 41 is such that only one tablet T conveyed by the conveyance belt 21 enters the imaging field of view, and the tablets T on the upstream or downstream side in the conveyance direction A1 or the tablets T in the next row do not enter. Is set to The imaging unit 41 performs imaging at a timing when the tablet T reaches immediately below, acquires an image including the upper surface of the tablet T, and transmits the acquired image to the image processing device 80. As the imaging unit 41, for example, various cameras having an imaging device such as a CCD (charge coupled device) and a CMOS (complementary metal oxide semiconductor) can be used. Each of the imaging units 41 is electrically connected to the control device 90 via the image processing device 80, and their driving is controlled by the control device 90. In addition, illumination for imaging is provided as needed.

  The printing device 50 includes a plurality of print heads 51 of an ink jet system. Each print head 51 is provided above the transport belt 21 one by one for each transport belt 21 and is positioned downstream of the imaging device 40 in the transport direction A1. These print heads 51 are displaced by a predetermined distance (for example, a distance longer than the width of the print head 51 in the transport direction A1) in the transport direction A1, and are configured not to hinder each other from moving with respect to the maintenance device 70. Have been. The print head 51 includes a plurality of nozzles 51a (see FIG. 2), and individually discharges ink (an example of a liquid) from the nozzles 51a. The print head 51 is provided such that the nozzle alignment direction in which the nozzles 51a are arranged intersects (for example, orthogonally) in the horizontal plane with the transport direction A1. As the print head 51, for example, it is possible to use various inkjet print heads having a driving element such as a piezoelectric element, a heating element, or a magnetostrictive element. The print head 51 is electrically connected to the control device 90, and its driving is controlled by the control device 90.

  The collection device 60 is positioned downstream of the printing device 50 in the transport direction A1, and is provided at an end of the transport device 20, that is, at an end of each transport belt 21 on the downstream side in the transport direction A1. The collection device 60 is configured to sequentially receive and collect the tablets T that have been released from being held by the transport belts 21 and fall. The transport device 20 releases the holding of the tablets T when the individual tablets T on each of the transport belts 21 reach a desired position, for example, the downstream end of each transport belt 21 in the transport direction A1. .

  The maintenance device 70 includes a liquid receiving unit 71 and a moving device 72, as shown in FIG. 1 and 2, the moving device 72 is omitted for simplification of the drawings.

  The liquid receiving portion 71 is formed, for example, in a box shape having an open upper portion, and is provided between two adjacent conveyor belts 21. The liquid receiving section 71 receives the ink discharged from each nozzle 51a of the print head 51 facing during maintenance. The upper end of the liquid receiving portion 71 is located at a position lower than the upper surface of the transport belt 21 so as not to hinder the movement of the print head 51. The width of the liquid receiving portion 71 in the direction orthogonal to the transport direction A1 is substantially the same as the width of the print head 51 in the same direction (substantially the same as the width of one head, and at least larger than the width of two heads). Also short). The print heads 51 are provided around the liquid receiving portion 71, and the print heads 51 are provided above the transport belt 21 so as to be close to the liquid receiving portion 71 for each of the transport belts 21. I have. Here, the two conveyor belts 21 are separated from each other by a predetermined distance, that is, a distance at which the maintenance device 70 can be installed. This separation distance is maintained at a predetermined distance. This is because, for example, when the two conveyor belts 21 are maintained, the respective conveyor belts 21 may be removed, but the conveyor belts 21 may be removed only in the same direction (one direction).

  The moving device 72 has a pair of moving mechanisms 72a and 72b and a pair of support bases 72c and 72d. The pair of moving mechanisms 72a and 72b are positioned on the downstream side in the transport direction A1 from the imaging device 40, and are provided above each transport belt 21 and the liquid receiving unit 71 along a direction orthogonal to the transport direction A1 on a horizontal plane. ing. The pair of support tables 72c, 72d are arranged in a direction orthogonal to the transport direction A1 so as to sandwich the transport device 20, and support both ends of the pair of moving mechanisms 72a, 72b. Each of the moving mechanisms 72a and 72b movably supports the print head 51 in a direction perpendicular to the transport direction A1, and the maintenance position where the print head 51 faces the liquid receiving portion 71 and the print position where the print head 51 faces the transport belt 21. The print head 51 is moved to (application position). The pair of moving mechanisms 72a and 72b are electrically connected to the control device 90, and their driving is controlled by the control device 90.

  Here, the maintenance position is a position at which the print head 51 ejects ink toward the liquid receiving unit 71. This maintenance position is provided for each print head 51, and two maintenance positions exist above the liquid receiving portion 71. These maintenance positions are arranged along the transport direction A1. Further, the printing position is a position for discharging ink toward the tablet T conveyed by the conveyance belt 21. The printing position is provided for each print head 51, and two printing positions exist above the first conveyor belt 21 and above the second conveyor belt 21. These printing positions are shifted by a predetermined distance in the transport direction A1. That is, in FIG. 3, the position of the print head 51 indicated by a solid line on the conveyor belt 21 is a printing position, and the position of the print head 51 indicated by a broken line on the liquid receiving unit 71 is a maintenance position.

  The image processing device 80 captures each image captured by the imaging device 40, processes each image using a known image processing technique, and shifts the tablet T in the X direction, the Y direction, and the θ direction (rotation direction). Is detected (see FIG. 3). Here, the displacement in the X direction and the Y direction is a displacement of the tablet T with respect to the center of the imaging visual field, and detects how much the tablet T is shifted with respect to the center. In the present embodiment, as an example, the transport direction A1 of the tablet T is the X direction, and the direction orthogonal thereto is the Y direction.

  The positional deviation in the θ direction is a rotational deviation of the tablet T in a horizontal plane. This positional deviation in the θ direction is caused when the tablet T has a directionality, such as when the tablet T is provided with a dividing line or when the tablet T is molded into an elliptical shape, an elliptical shape, or a rectangular shape. Is detected. For example, when a dividing line is formed on the tablet T, a state where the direction of the dividing line is parallel to the Y direction is set to 0 degree, and the θ deviation is obtained in units of 1 degree in a range of 0 to 179 degrees. I do. When the shape of the tablet T is not a line object with respect to the dividing line, the θ shift may be obtained in the range of 0 to 359 degrees. If the tablet T has no directivity, it is not necessary to detect θ shift.

  The image processing device 80 transmits the detected positional deviation information of each tablet T in the X direction, the Y direction, and the θ direction to the control device 90. When the image processing device 80 transmits the positional deviation information, it transmits the positional deviation information with the identification information of each imaging unit 41 added. Thereby, the control device 90 recognizes which row of the tablets T that are transmitted out of the tablets T conveyed in four rows by the two conveyor belts 21 are the pieces of positional shift information. can do.

  The control device 90 includes a microcomputer that centrally controls each unit, and a storage unit (neither is shown) that stores processing information, various programs, and the like. The control device 90 controls the supply device 10, the transport device 20, the imaging device 40, and the printing device 50 based on various information and various programs. Further, the control device 90 receives a detection signal transmitted from the detection device 30 or the position detector 24a, an image transmitted from the imaging device 40, and the like.

  In addition, the control device 90 detects the displacement in the X, Y, and θ directions based on the displacement information in the X, Y, and θ directions of each tablet T transmitted from the image processing device 80. The printing conditions for the tablet T are set. The storage unit stores print data including data such as print patterns such as characters and symbols to be printed on the tablets T and print positions of the characters and symbols on the tablets T. The moving speed information of the vehicle is stored.

  For example, the control device 90 determines the use range of the nozzles 51a used for the current printing in the print head 51 based on the displacement in the Y direction. As an example, among the plurality of nozzles 51a included in the print head 51, it is assumed that five nozzles 51a are used for applying the tablet T, and the positional shift amount of the tablet T in the Y direction is equivalent to one pitch of the arrangement interval of the nozzles 51a. Is satisfied, the printing conditions are set so as to use five nozzles 51a in which the use range of the nozzles 51a is shifted by one pitch in the direction of the positional shift of the tablet T.

  Further, the control device 90 determines the timing to start printing on the tablet T based on the displacement in the X direction. For example, when the tablet T is displaced upstream of the transport direction A1 by the distance ΔX, the time required for the transport belt 21 to move the distance ΔX is shorter than when the tablet T is not displaced in the X direction. The printing conditions are set so that printing is started at a timing that is only delayed.

  Further, the control device 90 sets the printing condition rotated in accordance with the rotational deviation of the tablet T based on the positional deviation in the θ direction. For example, in the storage unit of the control device 90, 180 types of print data in which the direction of a print pattern such as a character or a symbol is rotated by 1 degree within a range from 0 degree to 179 degrees are registered, and the print data is stored. From among these, the print data at an angle suitable for the detected misalignment in the θ direction is selected and the printing conditions are set.

(Printing process)
Next, a printing process (printing process) performed by the tablet printing apparatus 1 will be described.

  First, various information such as print data required for printing is stored in the storage unit of the control device 90. Further, a large number of tablets T to be printed are put into the hopper 11 of the supply device 10. When the tablet printing apparatus 1 is driven, each transport belt 21 of the transport apparatus 20 rotates in the transport direction A1 with the rotation of the driving pulley 22 and the driven pulley 23 by the driving unit 24. While the transport belts 21 are rotating, the tablets T are supplied from the supply device 10 onto the transport belts 21 at random, not at regular intervals. The tablets T are transported at a predetermined moving speed in two rows for each transport belt 21.

  Each tablet T on each conveyor belt 21 is detected by each detector 31 for each conveyor belt 21, and each detection signal from each detector 31 is input to the control device 90 as a trigger signal. Thereafter, each tablet T on each conveyor belt 21 is imaged by each imaging unit 41 for each conveyor belt 21. The upper surface of the tablet T is imaged by the imaging unit 41 at a timing based on the trigger signal described above, that is, at a timing when the tablet T reaches below the imaging unit 41, and the captured image is transmitted to the image processing device 80. Based on the individual images transmitted from each imaging unit 41, positional deviation information of the tablet T (for example, positional deviation of the tablet T in the X direction, the Y direction, and the θ direction) is generated by the image processing device 80, and the control device 90. Based on the positional shift information of the tablet T, the printing condition for the tablet T is set by the control device 90.

  Thereafter, the individual tablets T on each conveyor belt 21 are printed by the printing device 50 at the timing based on the trigger signal described above, that is, at the timing when the tablets T reach below the print head 51 based on the printing conditions described above. Be executed. In each print head 51 of the printing apparatus 50, ink is appropriately ejected from each nozzle 51a, and identification information such as characters and marks is printed on the upper surface of the tablet T. The ink applied to the tablet T is dried before the tablet T is collected by the collecting device 60. When the ink-dried tablet T is located at the downstream end of each conveyor belt 21, the tablet T is released from the state held by each conveyor belt 21, falls from each conveyor belt 21, and is collected by the collection device 60. .

(Maintenance process)
In such a printing process, the maintenance operation for the print head 51 is performed periodically for a predetermined time. When the maintenance operation is dummy ejection (when ink is ejected from the nozzle 51a by the ejection operation), the execution interval of the dummy ejection is, for example, 10 to 20 minutes, and the dummy ejection time is 1 to 5 seconds. A few seconds. Further, when the maintenance operation is pressure feeding (when ink is ejected from the nozzles 51a by pressurization), the execution interval of the pressure feeding is, for example, 30 to 40 minutes, and the pressure feeding time is 30 to 60 seconds. Ten seconds. Here, since the pumping time is longer than the dummy ejection time, in order to reduce the printing stop time due to the maintenance of the print head 51, the number of maintenances by the dummy ejection is increased and the number of maintenances by the pressure feeding is reduced. It is desirable. Therefore, by shortening the execution interval of the dummy ejection and lengthening the execution interval of the pressure feeding, it is possible to shorten the printing stop time due to the maintenance of the print head 51. Further, the amount of ink used during the dummy ejection is much smaller than the amount of ink used during the pressure feeding, so that the amount of ink used for maintenance can be reduced. Further, as maintenance, wiping for wiping off excess ink adhering to the nozzle surface of the print head 51 may be performed.

  In the maintenance process, the driving of the transport belts 21 is not stopped, the supply of the tablets T to the transport belts 21 is stopped by the supply device 10, and the maintenance of each print head 51 is performed. More specifically, after the supply of the tablets T is stopped, the unprinted tablets T that have not reached below the print head 51 on the conveyor belt 21 sequentially reach below the print head 51 for each of the conveyor belts 21, and the print head 51. Will be printed. After the printing is completed, each print head 51 is moved by the moving device 72 to the maintenance position facing the liquid receiving portion 71, respectively. Each of the print heads 51 moved to the maintenance position performs dummy ejection or pressure feeding for a predetermined time. After the maintenance operation is completed, each print head 51 is moved by the moving device 72 to the original print position facing the conveyor belt 21. After that, the supply of the tablets T is restarted by the supply device 10, and the printing is restarted by each print head 51 moved to the printing position. The maintenance start timing of each print head 51 may be the same or may be shifted.

  According to such a maintenance process, the supply of the tablets T is stopped for maintenance, but the stop time is suppressed. In either of the two print heads 51, the moving distance at the time of maintenance is substantially the shortest distance, so that the moving time of each print head 51 can be shortened.

  As described above, according to the first embodiment, the liquid receiving unit 71 functioning as a maintenance unit of the maintenance device 70 is provided between the two transport belts 21, and the two print heads 51 are For each 51, the moving device 72 moves to a printing position for discharging ink (an example of a liquid) toward the tablets T conveyed by the conveying belt 21 and a maintenance position for discharging ink toward the liquid receiving portion 71. I do. Accordingly, compared to a case where one liquid receiving unit 71 is provided outside one of the two conveyor belts 21 instead of between the two conveyor belts 21, the moving distance of both of the two print heads 51 during maintenance becomes shorter. In addition, the moving time of each print head 51 can be shortened. Accordingly, the time during which printing is stopped due to the maintenance of the print head 51 is reduced, so that a reduction in productivity due to printing stop can be suppressed. Further, by providing the liquid receiving portion 71 between the two transport belts 21, the liquid receiving portion 71 is one-sided compared to the case where the liquid receiving portion 71 is provided outside each of the two transport belts 21. Therefore, the tablet printing apparatus 1 can be downsized.

  As described above, the print heads 51 are offset from each other by being shifted in the transport direction A1. However, the present invention is not limited to this, and it is sufficient that the print heads 51 do not collide on the liquid receiving unit 71. For this reason, the print heads 51 for each of the transport belts 21 may be positioned on the same straight line, and an oblique or curved movement path may be provided so that the movement paths of the print heads 51 do not overlap. Further, even if the moving paths of the print heads 51 overlap, the timing may be shifted so that the print heads 51 do not enter the maintenance at the same timing.

(Second embodiment)
A second embodiment will be described with reference to FIG. In the second embodiment, differences from the first embodiment (the number of print heads and a maintenance process) will be described, and other description will be omitted.

  As shown in FIG. 4, in the second embodiment, four print heads 51 are provided, and the print positions are four. Here, for simplicity of description, the four print heads 51 are distinguished as a first print head 51, a second print head 51, a third print head 51, and a fourth print head 51, and in FIG. Reference numerals 1, 2, 3 and 4 are written on the four print heads 51.

  The first print head 51 and the second print head 51 are arranged in the X direction so as to be parallel to each other. The third print head 51 and the fourth print head 51 are also arranged in the X direction so as to be parallel to each other. The first print head 51 and the third print head 51 are individually moved in the Y direction by the moving mechanism 72a. The second print head 51 and the fourth print head 51 are individually moved in the Y direction by the moving mechanism 72b. In addition, the first print head 51 and the third print head 51 form a set sharing one maintenance position, and the second print head 51 and the fourth print head 51 form a set sharing one maintenance position. .

  In the first maintenance step (alternate printing), the first print head 51 and the second print head 51 do not perform printing at the same time, and if either one is performing printing, the other performs maintenance. I do. Similarly, the third print head 51 and the fourth print head 51 do not perform printing at the same time, and when one of them is performing printing, the other performs maintenance. Further, the print heads 51 of the set sharing the maintenance position do not execute printing at the same time.

  For example, when a predetermined time elapses after the first print head 51 and the fourth print head 51 start printing, the first print head 51 and the fourth print head 51 stop printing, and are in a standby state together therewith. The second print head 51 and the third print head 51 start printing. When the switching of the print heads 51 is completed, the first print head 51 and the fourth print head 51 move from the print position to the maintenance position, and start maintenance. Thereafter, when the maintenance is completed, the first print head 51 and the fourth print head 51 move from the maintenance position to the printing position, respectively, and wait for the next printing.

  Next, when a predetermined time has elapsed since the second print head 51 and the third print head 51 started printing, the second print head 51 and the third print head 51 stop printing, and are in a standby state together therewith. The first print head 51 and the fourth print head 51 start printing. When the switching of the print heads 51 is completed, the second print head 51 and the third print head 51 move from the print position to the maintenance position, and start maintenance. Thereafter, when the maintenance is completed, the second print head 51 and the third print head 51 move from the maintenance position to the printing position, respectively, and wait for the next printing. Such an operation is repeated.

  The maintenance is performed every predetermined time, but the predetermined time in the first maintenance step is set to a time during which the print head 51 waiting at the printing position can perform printing as it is. For example, while the first print head 51 is printing, the second print head 51 is waiting at the print position. If the waiting time becomes long, the ink of each nozzle 51a of the second print head 51 dries, and an ejection failure may occur. For this reason, the above-mentioned predetermined time is set experimentally or theoretically in advance so that the ejection failure does not occur. However, the predetermined time does not necessarily have to be set as described above.For example, when the print head 51 waiting at the print position performs printing, the print head 51 moves to the maintenance position and performs dummy ejection before printing. It is also possible to return to the printing position and start printing. In addition, since the print heads 51 of the set sharing the maintenance position are prevented from simultaneously performing printing, the print heads 51 of the respective transport belts 21 do not move to the maintenance position at the same time, and the print heads 51 are moved to the maintenance position. There is no collision.

  In the second maintenance step (full printing), each print head 51 performs printing together. The first print head 51 and the second print head 51 alternately perform printing every predetermined time (for example, one minute). Similarly, the third print head 51 and the fourth print head 51 alternately perform printing every predetermined time (for example, one minute). A maintenance target is selected from the print heads 51 by the control device 90 based on the number of times of individual driving, and maintenance is performed on the selected print head 51. Since the interval at which the tablets T are transported is not constant, the frequency of use of each print head 51 is different.

  The control device 90 can grasp the number of times of driving of each of the print heads 51 (for example, the number of times of driving of the drive element), and perform printing for maintenance according to the number of times of driving of each of the print heads 51. The head 51 is selected. For example, among the print heads 51, the print head 51 whose drive count has reached a predetermined count is set as the print head 51 to be maintained. However, the control device 90 does not set the first print head 51 and the second print head 51 at the same time as the maintenance target, and does not set the third print head 51 and the fourth print head 51 at the same time as the maintenance target. Adjust the selections described above. Similarly, the control device 90 sets the first print head 51 and the third print head 51 not to be simultaneously targeted for maintenance, and also sets the second print head 51 and the fourth print head 51 to be simultaneously targeted for maintenance. Adjust the above selection so that it does not.

  According to the above-described first or second maintenance process, the supply of the tablets T is not stopped for the maintenance, and the tablets T are sequentially supplied to each of the transport belts 21, and are supplied by one of the print heads 51. Printing is performed. As a result, the print stop time due to the maintenance of the print head 51 is eliminated, so that it is possible to suppress a decrease in productivity due to the print stop due to the maintenance.

  In the second maintenance step, maintenance can be performed according to the actual frequency of use of the print heads 51 by counting the number of times each print head 51 is driven. Accordingly, unnecessary maintenance can be omitted, productivity can be improved, and stable printing can be performed on the tablets T that are randomly transported. In addition to the number of times of driving of the drive element for each print head 51, for example, the maintenance target is determined from each print head 51 according to the number of prints for each print head 51 (the number of printed tablets T for each print head 51). It is also possible to select.

  As described above, according to the second embodiment, the same operation and effect as those of the first embodiment can be obtained. Further, since the printing is continued by any one of the print heads 51, the printing stop time due to the maintenance can be eliminated, and the reduction in productivity due to the printing stop due to the maintenance can be suppressed.

(Third embodiment)
A third embodiment will be described with reference to FIG. In the third embodiment, differences from the first embodiment (the number of print heads and a maintenance process) will be described, and other description will be omitted.

  As shown in FIG. 5, in the third embodiment, four print heads 51 are provided, and the print positions are four. Here, for simplification of description, the four print heads 51 are distinguished as a first print head 51, a second print head 51, a third print head 51, and a fourth print head 51, and in FIG. 1, 2, 3 and 4 on the four print heads 51. Further, the two conveyor belts 21 are distinguished as a first conveyor belt 21 and a second conveyor belt 21, and reference numerals 1 and 2 are written on the two conveyor belts 21 in FIG.

  The first print head 51 and the second print head 51 are arranged in the Y direction. The third print head 51 and the fourth print head 51 are also arranged in the Y direction. The first print head 51 and the second print head 51 arranged in the Y direction are moved together in the Y direction by the moving mechanism 72a. Similarly, the third print head 51 and the fourth print head 51 arranged in the Y direction are moved together in the Y direction by the moving mechanism 72b. Note that the first print head 51 and the second print head 51 form a set sharing one maintenance position, and the third print head 51 and the fourth print head 51 form a set sharing one maintenance position. .

  In the first print head 51 and the second print head 51, when the first print head 51 is located at the printing position of the first transport belt 21, the second print head 51 is located at the maintenance position. When the first print head 51 is at the maintenance position, the second print head 51 is at the print position of the second transport belt 21. Similarly, in the third print head 51 and the fourth print head 51, when the third print head 51 is located at the maintenance position, the fourth print head 51 is moved to the print position of the second transport belt 21. Exists. When the third print head 51 is located at the printing position of the first transport belt 21, the fourth print head 51 is located at the maintenance position.

  In the maintenance process, when a predetermined time elapses after the first print head 51 and the fourth print head 51 start printing, the first print head 51 and the fourth print head 51 stop printing, and perform printing. Move from the position to the maintenance position and start maintenance. Along with this movement, the second print head 51 moves from the maintenance position to the printing position of the second conveyor belt 21, and the third print head 51 moves from the maintenance position to the printing position of the first conveyor belt 21. And start printing. When the maintenance is completed, the first print head 51 and the fourth print head 51 stand by at the maintenance positions.

  Thereafter, when a predetermined time elapses after the second print head 51 and the third print head 51 start printing, the second print head 51 and the third print head 51 stop printing, and the respective print heads move from the print position. Move to the maintenance position and start maintenance. Along with this movement, the first print head 51 moves from the maintenance position to the printing position of the first transport belt 21, and the fourth print head 51 moves from the maintenance position to the printing position of the second transport belt 21. And start printing. Such processing is repeated.

  The maintenance is performed every predetermined time, but the predetermined time in the maintenance process is set to a time during which the print head 51 waiting at the printing position can perform printing as it is. For example, while the first print head 51 is printing, the second print head 51 is waiting at the maintenance position. If the waiting time becomes long, the ink of each nozzle 51a of the second print head 51 dries, and an ejection failure may occur. For this reason, the above-mentioned predetermined time is set experimentally or theoretically in advance so that the ejection failure does not occur. However, the predetermined time does not necessarily have to be set as described above. For example, when the print head 51 waiting at the maintenance position performs printing, dummy ejection is performed before moving to the printing position, and then printing is performed. It is also possible to move to the position and start printing.

  According to this maintenance process, the supply of the tablets T is not stopped for maintenance, and the tablets T are sequentially supplied to the respective transport belts 21 and printed by any of the print heads 51. As a result, the print stop time due to the maintenance of the print head 51 is eliminated, so that it is possible to suppress a decrease in productivity due to the print stop due to the maintenance.

  The moving speed and the like of each print head 51 are set so that tablets T that are not printed during the movement of each print head 51 do not occur. However, if the separation distance between the tablets T adjacent in the X direction is very short, the tablets T that are not printed may be generated during the movement of each print head 51. Therefore, the supply of the tablets T is stopped for a predetermined time (several seconds). Then, the separation distance between the tablets T adjacent in the X direction is increased. Accordingly, it is possible to prevent the generation of tablets T that are not printed during the movement of each print head 51.

  As described above, according to the third embodiment, the same functions and effects as those of the first embodiment can be obtained. Further, since the printing is continued by any one of the print heads 51, the printing stop time due to the maintenance can be eliminated, and the reduction in productivity due to the printing stop due to the maintenance can be suppressed.

(Fourth embodiment)
A fourth embodiment will be described with reference to FIG. In the fourth embodiment, differences (maintenance devices) from the first embodiment will be described, and other descriptions will be omitted.

  As shown in FIG. 6, a maintenance device 70 according to the fourth embodiment includes a discharge pipe 73 and a storage unit 74 in addition to a liquid receiving unit 71 and the like. The bottom surface of the liquid receiving portion 71 is inclined so as to gradually decrease toward one of both ends in the Y direction on the bottom surface. A discharge port 71a is formed at one end thereof, and one end of a discharge pipe 73 is connected to the discharge port 71a. The other end of the discharge pipe 73 is connected to the storage part 74. The ink discharged from each nozzle 51a of the print head 51 located at the maintenance position hits the bottom surface of the liquid receiving portion 71, moves along the bottom surface, and flows into the discharge pipe 73 from the discharge port 71a. The storage section 74 stores the ink flowing out of the discharge pipe 73. Note that the bottom surface of the liquid receiving portion 71 may be inclined in any direction, as long as it is inclined toward the location where the discharge port 71a is formed. Further, the numbers of the discharge ports 71a, the discharge pipes 73, and the storage sections 74 are not particularly limited.

  A filter 73a is provided inside the discharge pipe 73 described above. The filter 73a removes foreign matter such as powder of the tablet T from the ink flowing through the discharge pipe 73. Further, a sensor (detection unit) 75 for detecting clogging of the filter 73a is provided. An alarm (not shown) is connected to the control device 90. The annunciator issues a warning urging the maintenance of the filter 73a according to the detection result of the sensor 75. As the alarm, for example, a lamp, a buzzer, a display, or the like can be used. Note that such a filter 73a and an alarm may be provided as needed, and may not be provided.

  In the maintenance process, the ink discharged from each nozzle 51a of the print head 51 located at the maintenance position hits the bottom surface of the liquid receiving portion 71, and flows toward the discharge port 71a along the bottom surface according to the inclination of the bottom surface. The ink flows into the discharge pipe 73 from the discharge port 71a, flows into the storage 74 via the discharge pipe 73, and is stored by the storage 74. In the maintenance process by the pressure feeding, the amount of ink ejected from each nozzle 51a of the print head 51 is larger than that in the maintenance process by the dummy ejection. When a large amount of ink accumulates on the bottom surface of the liquid receiving section 71, the tendency of liquid splash to occur at the next maintenance is increased. Therefore, by providing the discharge pipe 73 and the storage section 74, it is possible to suppress accumulation of a large amount of ink on the bottom surface of the liquid receiving section 71, and it is possible to suppress contamination of the print head 51 and the like due to liquid splash. .

  As described above, according to the fourth embodiment, the same functions and effects as those of the first embodiment can be obtained. Further, by providing the discharge pipe 73 and the storage section 74, it is possible to suppress the accumulation of a large amount of ink on the bottom surface of the liquid receiving section 71, and the surfaces of the print head 51 and the transport belt 21 due to liquid splash (for example, It is possible to suppress contamination of the surface of the belt on which the tablets T are placed), the tablets T being conveyed, and the like.

(Fifth embodiment)
A fifth embodiment will be described with reference to FIG. Note that, in the fifth embodiment, differences (maintenance devices) from the first embodiment will be described, and other descriptions will be omitted.

  As shown in FIG. 7, the liquid receiving portion 71 of the maintenance device 70 according to the fifth embodiment has a convex portion 71b on the bottom surface. As an example, the convex portion 71b is formed in a mountain shape with a peak extending in the X direction, and is formed so that ink ejected from each nozzle 51a of the print head 51 located at the maintenance position hits each inclined surface of the convex portion 71b. Have been. Therefore, it is desirable that the maximum length of the convex portion 71b in the Y direction is equal to or larger than the ink landing width on the bottom surface of the liquid receiving portion 71. The ink landing width is a width from the end to the end where ink ejected from each nozzle 51a of the print head 51 located at the maintenance position on the bottom surface lands. In addition, the shape of the convex portion 71b may be a mountain shape having a peak at one point, or may be a V-shape or a funnel shape.

  In the maintenance process, ink ejected from each nozzle 51a of the print head 51 located at the maintenance position hits each inclined surface of the convex portion 71b of the liquid receiving portion 71, flows along the inclined surface, and moves in the Y direction on the bottom surface. Move towards both ends of the. Here, if the bottom surface of the liquid receiving portion 71 is flat, the ink is accumulated in the landing area of the bottom surface where the ink is applied, so that the liquid splash is likely to occur at the next maintenance or the like. Therefore, by providing the convex portion 71b on the bottom surface of the liquid receiving portion 71, ink ejected from each nozzle 51a of the print head 51 located at the maintenance position flows along each inclined surface of the convex portion 71b, It will collect outside the landing area on the bottom surface of the portion 71. As a result, it is possible to suppress accumulation of ink in the landing area on the bottom surface of the liquid receiving section 71, and it is possible to suppress contamination of the print head 51 and the like due to liquid splashing. When the bottom surface is flat, the direction of the liquid splash is random, but by adjusting the angle of each inclined surface, the direction of the liquid splash can be adjusted to some extent.

  As described above, according to the fifth embodiment, the same functions and effects as those of the first embodiment can be obtained. Further, by providing the convex portion 71 b on the bottom surface of the liquid receiving portion 71, it is possible to suppress accumulation of ink in the landing area on the bottom surface of the liquid receiving portion 71. The surface 21 (for example, the surface of the belt on which the tablets T are placed), and the contamination of the tablets T during transportation can be suppressed.

(Sixth embodiment)
A sixth embodiment will be described with reference to FIG. In the sixth embodiment, differences (maintenance devices) from the first embodiment will be described, and other descriptions will be omitted.

  As shown in FIG. 8, the maintenance device 70 according to the sixth embodiment includes a plurality of suction pipes 76 and suction units 77 in addition to the liquid receiving unit 71 and the like. Two suction ports 71c are formed on the bottom surface of the liquid receiving portion 71, and these suction ports 71c are arranged in the X direction. Each suction port 71c is formed in a rectangular slit longer than the length of the nozzle row. One end of each suction pipe 76 is individually connected to these suction ports 71c. The other end of each suction tube 76 is connected to a suction unit 77. The suction unit 77 is, for example, a suction pump or the like, and generates a suction force. The suction unit 77 includes a liquid recovery unit such as a liquid trap and a filter (both not shown). The suction unit 77 is electrically connected to the control device 90, and its driving is controlled by the control device 90.

  Here, each suction port 71c is provided corresponding to each maintenance position located above the liquid receiving portion 71, and is provided on the bottom surface of the liquid receiving portion 71 so as to face the print head 51 existing at the maintenance position. Each is formed. These suction ports 71c are formed to have a size such that ink discharged from each nozzle 51a of the print head 51 located at the maintenance position passes and does not rebound. Therefore, the length of the suction port 71c in the Y direction is equal to or larger than the ink landing width on the bottom surface of the liquid receiving portion 71. The ink landing width is a width from the end to the end where ink ejected from each nozzle 51a of the print head 51 located at the maintenance position on the bottom surface lands.

  In the maintenance process, the suction unit 77 is driven by the control device 90, and air is sucked from the two suction ports 71c on the bottom surface of the liquid receiving unit 71. In this state, the ink discharged from each nozzle 51 a of the print head 51 located at the maintenance position passes through the suction port 71 c of the liquid receiving section 71 and is sucked by the suction pipe 76. This ink flows through the suction tube 76 and is collected by the liquid collecting unit of the suction unit 77. The suction unit 77 is driven at the time of performing maintenance, and is not driven at normal times other than at the time of performing maintenance. However, it is also possible to share the suction device of the transport device 20 as the suction unit 77. In this case, since the suction device is constantly driven, air is constantly sucked from each suction port 71c.

  Here, when the ink strikes the bottom surface of the liquid receiving portion 71, the ink may jump, and the mist may be generated by the rising of the droplet. For this reason, by forming the suction port 71c on the bottom surface of the liquid receiving portion 71 so as to face the print head 51 located at the maintenance position, it is possible to suppress the soaring of droplets, that is, the generation of mist during maintenance. Become. Accordingly, contamination of the print head 51 and the transport belt 21 around the liquid receiving portion 71 by the mist can be suppressed.

  As described above, according to the sixth embodiment, the same operation and effect as those of the first embodiment can be obtained. Further, by forming the suction port 71c on the bottom surface of the liquid receiving portion 71 so as to face the print head 51 located at the maintenance position, it is possible to suppress the soaring of droplets, that is, the generation of mist during maintenance. Therefore, the contamination of the print head 51 and the transport belt 21 around the liquid receiving portion 71 by the mist can be suppressed.

(Seventh embodiment)
A seventh embodiment will be described with reference to FIG. In the seventh embodiment, a difference (maintenance device) from the sixth embodiment will be described, and other description will be omitted.

  As shown in FIG. 9, in the seventh embodiment, two suction ports 71c are formed on the bottom surface of the liquid receiving section 71, and the suction pipes 76 are individually connected to the suction ports 71c. The two suction ports 71c are formed at both ends in the Y direction on the bottom surface of the liquid receiving portion 71. In addition, these suction ports 71c are formed to extend in the X direction over the bottom surface of the liquid receiving portion 71. The bottom surface of the liquid receiving portion 71 is inclined so as to gradually decrease toward the center. The two suction pipes 76 suction the mist generated in the liquid receiving unit 71 via the suction ports 71c. As described above, the mist is generated by the ink ejected from the print head 51 located at the maintenance position splashing on the bottom surface of the liquid receiving portion 71, and the liquid droplets soar.

  In the maintenance process, the suction unit 77 is driven by the control device 90, and air is sucked from the two suction ports 71c of the liquid receiving unit 71. In this state, the ink ejected from each nozzle 51a of the print head 51 located at the maintenance position hits the bottom surface of the liquid receiving portion 71, flows along the slope of the bottom surface, and gradually accumulates at the center of the bottom surface. At this time, even if mist is generated due to rising of the droplet, the mist is sucked by the two suction pipes 76 together with air. Accordingly, the mist can be removed at the time of maintenance, so that contamination of the print head 51 and the transport belt 21 around the liquid receiver 71 due to the mist can be suppressed.

  In addition, it is also possible to connect a discharge pipe (not shown) to the center of the bottom surface. In this case, the ink that has moved to the center of the bottom surface flows into the discharge pipe and is discharged by the discharge pipe. Accordingly, it is possible to suppress accumulation of ink in the landing area on the bottom surface of the liquid receiving section 71, and it is possible to suppress contamination of the print head 51 due to liquid splash.

  As described above, according to the seventh embodiment, the same functions and effects as those of the first embodiment can be obtained. Further, by forming the suction port 71c at any place on the bottom surface of the liquid receiving portion 71, it becomes possible to remove mist generated by the soaring of the droplets during maintenance. Contamination of the transport belt 21 and the like around the receiving portion 71 can be suppressed.

(Eighth embodiment)
An eighth embodiment will be described with reference to FIG. Note that, in the eighth embodiment, a difference (maintenance device) from the seventh embodiment will be described, and other description will be omitted.

  As shown in FIG. 10, in the eighth embodiment, two gas blowing sections 78 are provided. These gas blowing sections 78 are provided at positions higher than the upper end of the print head 51 so as not to hinder the movement of the print head 51. Further, each gas blowing section 78 is arranged to face each suction port 71c of the liquid receiving section 71, respectively. These gas blowing portions 78 are formed to extend in the X direction. A slit-shaped blowout hole (not shown) extending in the X direction is formed at a lower portion of each gas blowing portion 78. Therefore, the gas blowing unit 78 blows a gas (for example, air or nitrogen) downward to form a gas curtain. Each gas blowing section 78 is electrically connected to a control device 90, and the driving thereof is controlled by the control device 90.

  In the maintenance process, each of the gas blowing units 78 is driven by the control device 90, and air (an example of gas) is blown out of the gas blowing units 78 and is sucked through the two suction ports 71 c of the liquid receiving unit 71. Thereby, airflow curtains, that is, air curtains (an example of gas curtains) are formed on both sides of the print head 51. As in the seventh embodiment, when ink strikes the bottom surface of the liquid receiving portion 71, mist may be generated by the rising of the liquid droplets. Suctioned by 76. Further, even if a large amount of mist is generated, the air curtain suppresses the mist from flowing out from the upper opening of the liquid receiving portion 71 toward the transport belt 21. In this manner, mist removal during maintenance and mist outflow can be suppressed, so that contamination of the print head 51 and the transport belt 21 around the liquid receiving portion 71 due to mist can be suppressed. In addition, by sucking the gas from below the gas blowing unit 78 (lower suction), it is possible to suppress the width of the air curtain from being widened, so that printing near the air curtain is not affected. .

In addition, as shown in FIG. 11, in the modified example, in addition to the two gas blowing sections 78 described above, a suction head 79 is provided for each of the gas blowing sections 78. The gas blowing part 78, to form an air curtain between the transport belt 21 and the liquid receiving portion 71, so as to extend parallel to the conveying direction A1 of the tablet agent T between the transport belt 21 and the liquid receiver 71 It has a formed blow-off hole for blowing gas. The suction head 79 is formed in a gutter shape having an open upper surface and extending in the X direction, and has a suction port 79a extending in the X direction. The suction head 79 is positioned below the gas blowing section 78 and lower than the liquid receiving section 71, and is provided such that the suction port 79 a faces the gas blowing section 78. The suction head 79 is connected to the suction unit 77 via a suction tube (not shown). The suction head 79 sucks the gas blown out from the gas blowing unit 78 and passing between the transport belt 21 and the liquid receiving unit 71. As a result, the air curtain is formed outside the liquid receiving portion 71, and is formed along the extending direction of the transport belt 21, that is, along the transport direction A1 (for example, parallel to the transport belt 21). Note that a suction mechanism using the suction head 79 or the above-described suction pipe 76 is not essential, and only an air curtain may be formed.

  As described above, according to the eighth embodiment, the same functions and effects as those of the first embodiment can be obtained. Further, by providing the gas blowing unit 78, even if a large amount of mist is generated, the air mist (an example of an air flow curtain) prevents the mist from flowing out from the upper opening of the liquid receiving unit 71 to the transport belt 21 side. Since it is possible to suppress the contamination, the contamination of the transport belt 21 and the like around the liquid receiving portion 71 by the mist can be surely suppressed.

(Other embodiments)
In each of the above-described embodiments, the use of the hopper 11 and the shooter 12 as the supply device 10 has been exemplified. However, the present invention is not limited thereto, and various supply mechanisms can be used. For example, it is possible to provide a delivery mechanism that sucks and transports the tablet T on the lower surface, and supply the tablet T to the transport device 20 by this delivery mechanism. In this case, in order to stop the supply of the tablets T to the transport device 20, the suction by the delivery mechanism may be stopped.

  Further, in each of the above-described embodiments, the example in which the tablets T are transported in two rows by the transport belt 21 is exemplified. However, the present invention is not limited thereto, and the tablets T may be arranged in one row, three rows, or four rows or more. The number is not particularly limited. In addition, it is possible to perform printing on two or more rows of tablets T by one print head 51, but it is not limited to this. For example, the print heads 51 may be provided for each row.

  Further, in each of the above-described embodiments, the case where only two conveyor belts 21 are provided is exemplified. However, the present invention is not limited to this, and two or more conveyor belts 21 may be provided. For example, as shown in FIG. 12, when three transport belts 21 are provided, it is possible to provide the liquid receiving portions 71 between all the individual transport belts 21. That is, the number of transport paths for the tablets T is not limited to two (two rows), and may be more than two. The liquid receiving section 71 is provided between the respective transport paths. Further, the transport path is not limited to the transport belt 21, but may be a transport path using, for example, a cylindrical drum, a tray, or a pallet.

  Further, in each of the above-described embodiments, the transport device that holds and transports the tablet T by suction is illustrated as the transport device 20, but the transport device is not limited to this, and various transport mechanisms can be used. . Further, as a holding mechanism for sucking and holding the tablet T, the holding of the tablet T by the slit-shaped suction port 21a extending in the transfer direction A1 is exemplified, but the present invention is not limited to this. The tablets T may be held by a plurality of lined circular suction ports.

  In the above-described embodiments, the timing of printing is set based on the detection device 30. However, the present invention is not limited to this. For example, the timing of printing may be set based on the imaging device 40. .

  Further, in each of the above-described embodiments, as the inkjet print head 51, a print head in which the nozzles 51a are arranged in a line is exemplified. However, the present invention is not limited to this. For example, a print head in which the nozzles 51a are arranged in a plurality of lines is used. It may be used.

  Further, in each of the above-described embodiments, the case where the liquid receiving portion 71 is fixedly provided is exemplified. However, the present invention is not limited to this. For example, the liquid receiving portion 71 may be moved by a moving mechanism. For example, a vertical moving mechanism that moves the liquid receiving unit 71 in the vertical direction can be provided as the moving mechanism. In this case, at the time of maintenance, the separation distance between the print head 51 located at the maintenance position and the liquid receiving unit 71 can be adjusted.

  Further, in each of the above-described embodiments, the case where the liquid receiving unit 51 is provided as a maintenance unit for performing maintenance is exemplified. However, the present invention is not limited thereto. For example, in addition to the liquid receiving unit 51, Instead of the receiving section 51, a wiping section for wiping off excess ink adhering to the nozzle surface of the print head 51 can be provided. Further, another maintenance mechanism can be provided as the maintenance unit.

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

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

  Although some 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 new embodiments can be implemented in other various forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and their equivalents.

DESCRIPTION OF SYMBOLS 1 Tablet printing apparatus 21 Conveyor belt 51 Print head 51a Nozzle 71 Liquid receiving part 71b Convex part 71c Suction port 72 Moving device 78 Gas blowing part T Tablet

Claims (2)

Tablets are transported, at least two transport routes,
A maintenance unit provided between the two transport paths and performing maintenance;
An inkjet print head that is provided above the transport path and around the maintenance unit for each of the transport paths and that discharges liquid from a nozzle,
A moving device that individually moves the print heads to a print position above the transport path and a maintenance position above the maintenance unit, provided for each print head,
With
Between the maintenance position and the printing position, and the outlet hole so as to extend in the conveying direction before SL tablets from the printing head above is formed, a gas blowing part blowing gas downward from the outlet hole A tablet printing apparatus, comprising: The tablet printing apparatus according to claim 1, further comprising a suction port that is arranged to face the gas blowing unit and suctions the gas blown out by the gas blowing unit.

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