WO2020090495A1

WO2020090495A1 - Tablet printing device

Info

Publication number: WO2020090495A1
Application number: PCT/JP2019/040866
Authority: WO
Inventors: 尚充伊藤; 信行中野; 貴之西川; 侑弥 ▲高▼畑
Original assignee: 株式会社Ｓｃｒｅｅｎホールディングス
Priority date: 2018-10-31
Filing date: 2019-10-17
Publication date: 2020-05-07
Also published as: CN112955327B; KR20210060544A; CN112955327A; KR102420907B1; JP2020069106A; JP7103918B2

Abstract

This inkjet tablet printing device (1) has: a head (21) having a plurality of ink nozzles (211) on a lower surface thereof; a tablet transport mechanism (10); a partition wall (60) that separates a printing space (A1) in which the transport mechanism (10) is disposed and an evacuation space (A2); a shutter (72) provided to the partition wall (60); a movement mechanism (22) for moving the head (21) between a printing position (P1) and an evacuation position (P2); and a cap (23) that covers the ink nozzles (211) at the evacuation position (P2). The shutter (72) has a through hole (720) in which the head (21) is disposed. At the printing position (P1), one end surface of the head (21) and the ink nozzles (211) are arranged in the printing space (A1), and the other end surface of the head (21) is disposed in the evacuation space (A2). At the evacuation position (P2), the one end surface of the head (21) is disposed in the printing space (A1), and the other end surface of the head (21) and the ink nozzles (211) are arranged in the evacuation space (A2). Accordingly, it is possible to suppress entry of fine powder of a tablet from the printing area to an adjacent area.

Description

Tablet printing equipment

The present invention relates to a tablet printing device that prints on the surface of tablets.

Characters and codes for identifying products are printed on the surface of tablets, which are a form of pharmaceutical products. Such characters and codes may be printed by engraving, but the engraving has a problem of low visibility. Particularly, in recent years, the types of tablets have been diversified due to the popularization of generic drugs. Therefore, in order to make the tablets easy to identify, a technique of performing clear printing by an inkjet method on the surface of the tablets has been attracting attention.

Patent Document 1 describes an example of a conventional apparatus that prints on the surface of a tablet by an inkjet method.

JP, 2017-205384, A

An inkjet type tablet printing device ejects ink droplets (hereinafter simply referred to as "ink droplets") toward the tablet from a plurality of nozzles provided on the ejection surface of the head while conveying the tablet. Such an ink jet type printing apparatus is provided with a cap that covers the nozzle when ink is not ejected and a mechanism that performs maintenance of the nozzle provided in the cap, as described in Japanese Patent Application Laid-Open No. 2004-242242.

In the recording apparatus described in Patent Document 1, the head is arranged in the print area including the transport path when ejecting ink. On the other hand, when ink is not ejected, the head moves in the width direction and moves to the adjacent area (cleaning area) partitioned by the printing area and the partition. Then, in the area, the nozzle is covered with a cap in order to prevent the nozzle from drying.

However, during the transportation of tablets, fine powder of tablets is scattered around the transportation route. Since the head moves back and forth between the print area and the adjacent area, the print area and the adjacent area communicate with each other at least when the head moves. At this time, since the fine powder of the tablet may enter the adjacent area, it is necessary to perform maintenance for removing the fine powder in the adjacent area.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a tablet printing apparatus that can prevent fine powder of tablets from entering the adjacent area from the printing area.

In order to solve the above problems, a first invention of the present application is an inkjet-type tablet printing apparatus, which includes a head having a lower surface on which a plurality of ink nozzles for ejecting ink droplets are arranged, and a tablet to be printed. A transport mechanism for transporting in the transport direction, a partition for partitioning a printing space in which the transport mechanism is disposed and a retreat space, a shutter provided in the partition and having a through hole in which the head is disposed, and the head. A moving mechanism that moves at least the width direction between the print position and the retreat position, and a cap that covers the ink nozzle of the head at the retreat position, and one of the heads in the width direction of the head at the print position. Side end face and the ink nozzles are arranged in the printing space, and the end face on the other width direction side of the head is arranged in the retreat space, In serial retracted position, the end face of one side in the widthwise direction of the head is disposed in the printing space, an end surface and the ink nozzles of the other widthwise side of the head is disposed in the retraction space.

2nd invention of this application is a tablet printing apparatus of 1st invention, Comprising: The said shutter has a sealing member arrange | positioned at at least one part of the edge part of the said through-hole, The said head is the said printing position and Even when the moving mechanism contacts at least a part of the seal member and the moving mechanism moves the head between the printing position and the retracted position, the head has at least a part of the seal member. To contact.

A third invention of the present application is the tablet printing apparatus according to the second invention, wherein the seal member is arranged at least on an upper portion and a side portion of an edge portion of the rectangular through hole.

A fourth invention of the present application is the tablet printing apparatus according to any one of the first to third inventions, wherein the moving mechanism is capable of moving the head in a width direction and a vertical direction, and the shutter is It is movable in the vertical direction with respect to the partition.

5th invention of this application is a tablet printing apparatus of 4th invention, Comprising: The said partition is a shutter guide provided with the groove | channel which extends in an up-down direction at the both sides of the said shutter, and accommodates the side edge part of the said shutter. Have.

A sixth invention of the present application is the tablet printing apparatus according to any one of the first invention to the fifth invention, wherein the head has a cover attached to the lower surface, and the cover has a hole through which the ink nozzle is exposed. Parts.

A seventh invention of the present application is the tablet printing apparatus according to any one of the first to fifth inventions, wherein the plurality of ink nozzles are arranged inside a recess provided on the lower surface.

According to the first to seventh inventions of the present application, the gap between the printing space and the retreat space can be minimized by moving the head within the range where it does not come out of the through hole of the shutter. Thereby, it is possible to suppress the fine powder from entering the retreat space. Further, it is possible to suppress the fine powder from adhering to the nozzle of the head in the retreat space.

Particularly, according to the second invention of the present application, it is possible to suppress the fine powder from entering the retreat space from the gap between the head and the shutter by the contact of the head with the seal member.

It is the figure which showed the structure of the tablet printing apparatus. It is a partial perspective view of a tablet conveyance mechanism. It is a bottom view of a head. It is a block diagram showing a connection between a control unit and each unit in the tablet printing apparatus. It is a side view of a printing unit. FIG. 7 is a schematic diagram showing how the head moves. It is a top view of a shutter mechanism. FIG. 6 is a partial cross-sectional view of a partition wall, a shutter mechanism, and a head. It is a cross-sectional view of a shutter mechanism. It is an exploded perspective view of a shutter.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the direction in which a plurality of tablets are transported is referred to as the “transport direction”, and the direction that is vertical and horizontal to the transport direction is referred to as the “width direction”.

<1. Overall structure of tablet printing device>
FIG. 1 is a diagram showing a configuration of a tablet printing apparatus 1 according to an embodiment of the present invention. The tablet printing apparatus 1 is an apparatus that prints images such as a product name, a product code, a company name, and a logo mark on the surface of each tablet 9 while conveying a plurality of tablets 9 that are pharmaceutical products. As shown in FIG. 1, the tablet printing apparatus 1 of this embodiment includes a tablet transport mechanism 10, a printing unit 20, a drying mechanism 30, and a control unit 40.

The tablet transport mechanism 10 is a mechanism for transporting while holding a plurality of tablets 9 that are print targets. The tablet transport mechanism 10 has a pair of pulleys 11 and an annular transport belt 12 stretched between the pair of pulleys 11. The plurality of tablets 9 loaded into the tablet printing apparatus 1 are aligned at equal intervals by the carry-in mechanism 51 including a vibrating feeder, a conveyor drum, and the like, and are supplied to the outer peripheral surface of the conveyor belt 12. One of the pair of pulleys 11 is rotated by the power obtained from the transportation motor 13. As a result, the conveyor belt 12 rotates in the direction of the arrow in FIG. At this time, the other of the pair of pulleys 11 is driven to rotate as the conveyor belt 12 rotates.

FIG. 2 is a partial perspective view of the tablet transport mechanism 10. As shown in FIG. 2, the conveyor belt 12 is provided with a plurality of suction holes 14. The plurality of suction holes 14 are arranged at equal intervals in the carrying direction and the width direction. Further, as shown in FIG. 1, the tablet transport mechanism 10 has a suction mechanism 15 that sucks gas from the space inside the transport belt 12. When the suction mechanism 15 is operated, the space inside the conveyor belt 12 has a negative pressure lower than the atmospheric pressure. The plurality of tablets 9 are adsorbed and held in the adsorption holes 14 by the negative pressure.

As described above, the tablet transport mechanism 10 transports the tablets 9 by rotating the transport belt 12 while holding the tablets 9 in the suction holes 14 at regular intervals. Below the four heads 21, which will be described later, the plurality of tablets 9 are transported in the horizontal direction.

Further, as shown in FIG. 1, the tablet transport mechanism 10 has a blow mechanism 16 inside the transport belt 12. When the blow mechanism 16 is operated, of the plurality of suction holes 14 of the conveyor belt 12, only the suction holes 14 facing the carry-out mechanism 52 have a positive pressure higher than the atmospheric pressure. As a result, the suction of the tablet 9 in the suction hole 14 is released, and the tablet 9 is delivered from the conveyor belt 12 to the carry-out mechanism 52. The carry-out mechanism 52 carries out the tablets 9 delivered from the conveyor belt 12 to the outside of the tablet printing apparatus 1 by, for example, another conveyor belt.

The printing unit 20 is a unit that records an image on the surface of the tablet 9 conveyed by the conveyor belt 12 by an inkjet method. As shown in FIG. 1, the printing unit 20 of this embodiment has four heads 21. The four heads 21 are located above the transport belt 12 and are arranged in a line along the transport direction of the tablets 9. The four heads 21 eject ink droplets of different colors (for example, cyan, magenta, yellow, and black colors) toward the surface of the tablet 9. Then, a multicolor image is recorded on the surface of the tablet 9 by superposing the single color images formed by these respective colors. As the ink ejected from each head 21, an edible ink produced from a raw material approved by the Japanese Pharmacopoeia, Food Sanitation Law, etc. is used.

FIG. 3 is a bottom view of one head 21. In FIG. 3, the conveyor belt 12 and the plurality of tablets 9 held by the conveyor belt 12 are indicated by a chain double-dashed line. As shown enlarged in FIG. 3, a plurality of ink nozzles 211 capable of ejecting ink droplets are provided on the lower surface of the head 21. In this embodiment, a plurality of ink nozzles 211 are two-dimensionally arranged on the lower surface of the head 21 in the transport direction and the width direction. The respective ink nozzles 211 are arranged with their positions displaced in the width direction. By thus arranging the plurality of ink nozzles 211 two-dimensionally, the positions of the respective ink nozzles 211 in the width direction can be brought closer to each other. However, the plurality of ink nozzles 211 may be arranged in a line along the width direction.

As a method of ejecting ink droplets from the ink nozzles 211, for example, a so-called piezo method is used in which a piezoelectric element, which is a piezoelectric element, is deformed by applying a voltage to pressurize and eject the ink in the ink nozzle 211. .. However, the ink droplet ejection method may be a so-called thermal method in which the heater is energized to heat and expand the ink in the ink nozzle 211 to eject the ink.

The drying mechanism 30 is a mechanism for drying the ink attached to the surface of the tablet 9. The drying mechanism 30 is provided around the transport belt 12 on the downstream side of the printing unit 20 in the transport direction. For the drying mechanism 30, for example, a hot air supply mechanism that blows heated gas (hot air) toward the tablets 9 conveyed by the conveyor belt 12 is used. The ink attached to the surface of the tablet 9 is dried by hot air and fixed on the surface of the tablet 9.

The control unit 40 controls the operation of each unit in the tablet printing apparatus 1. FIG. 4 is a block diagram showing the connection between the control unit 40 and each unit in the tablet printing apparatus 1. As conceptually shown in FIG. 4, the control unit 40 is configured by a computer having a processor 41 such as a CPU, a memory 42 such as a RAM, and a storage unit 43 such as a hard disk drive. A computer program P for executing print processing is installed in the storage unit 43.

Further, as shown in FIG. 4, the control unit 40 communicates with the above-described transport motor 13, suction mechanism 15, blow mechanism 16, four heads 21, drying mechanism 30, carry-in mechanism 51, and carry-out mechanism 52, respectively. Connected possible. The control unit 40 is also communicatively connected to a vertical movement mechanism 222 and a horizontal movement mechanism 224, which will be described later. The control unit 40 temporarily reads the computer program P and data stored in the storage unit 43 into the memory 42, and the processor 41 performs arithmetic processing based on the computer program P to control the operation of each of the above units. To do. As a result, the printing process for the plurality of tablets 9 and the cleaning process for the head 21 proceed.

<2. Head moving mechanism and shutter mechanism>
FIG. 5 is a side view of the printing unit 20 as seen from the position of the outline arrow V in FIG. FIG. 6 is a schematic diagram showing how the head 21 moves. As shown in FIG. 5, the internal space of the tablet printing apparatus 1 is divided into a printing area A1 and a retreat area A2. The printing area A1 is a printing space for printing on the tablets 9 while the tablets 9 are transported by the tablet transport mechanism 10 described above. The retreat area A2 is a retreat space for retracting and waiting the head 21 before or after printing and accommodating equipment that does not need to be in the same space as the tablet 9.

A partition wall 60 is provided between the printing area A1 and the evacuation area A2 to partition both areas. The partition wall 60 is parallel to the transport direction of the tablets 9 and extends perpendicularly to the horizontal plane. As a result, the internal space of the tablet printing apparatus 1 is partitioned in the width direction into the printing area A1 and the retreat area A2. Below, the printing area A1 side with respect to the partition wall 60 will be referred to as one side in the width direction, and the retraction area A2 side with respect to the partition wall 60 will be referred to as the other side in the width direction.

The partition wall 60 has an opening 61 through which the head 21 passes. Further, the partition wall 60 includes a shutter mechanism 62 attached to the opening 61. The detailed configuration of the shutter mechanism 62 will be described later.

As described above, the printing unit 20 has the four heads 21. Further, as shown in FIG. 5, the printing unit 20 has a head moving mechanism 22 and a cap 23 for each head 21. That is, the printing unit 20 of the present embodiment has four heads 21, four head moving mechanisms 22 corresponding to each head 21, and four caps 23 corresponding to each head 21.

The head moving mechanism 22 is a mechanism that moves the head 21 between the printing position P1 and the retracted position P2. The head moving mechanism 22 of this embodiment has an arm 221, a vertical moving mechanism 222, a moving stage 223, and a horizontal moving mechanism 224.

The arm 221 is a member extending in the width direction. The head 21 is fixed to the tip of the arm 221 on one side in the width direction. The vertical movement mechanism 222 moves the arm 221 up and down according to a command from the control unit 40. As a result, the arm 221 and the head 21 move up and down as a unit.

The vertical movement mechanism 222 is supported by the movement stage 223. The horizontal moving mechanism 224 moves the moving stage 223 in the front-back direction. As a result, the moving stage 223, the vertical moving mechanism 222, the arm 221, and the head 21 integrally move in the width direction.

For the horizontal movement mechanism 224 and the vertical movement mechanism 222, for example, a mechanism that converts the rotational movement of the motor into a linear movement via a ball screw is used. However, the horizontal movement mechanism 224 and the vertical movement mechanism 222 may be realized by another mechanism such as a linear motor or an air cylinder.

As shown in FIGS. 5 and 6, the head moving mechanism 22 moves the head 21 in the vertical direction and the width direction between the printing position P1 and the retracted position P2. The head 21 prints on the tablets 9 at the printing position P1. At the retracted position P2, the plurality of ink nozzles 211 of the head 21 are covered by the cap 23. The first intermediate position P3 is a position above the printing position P1. The second intermediate position P4 is a position above the retracted position P2.

At the printing position P1, the end surface of the head 21 on one side in the width direction and the plurality of ink nozzles 211 are arranged in the printing area A1. Further, at the printing position P1, the end surface on the other side in the width direction of the head 21 is arranged in the retreat area A2. That is, the head 21 is partially arranged in the opening 61 provided in the partition wall 60. When the head 21 is arranged at the printing position P1, the plurality of ink nozzles 211 face the tablets 9 held by the conveyor belt 12.

At the retracted position P2, the end surface of the head 21 on one side in the width direction is arranged in the print area A1. Further, at the retreat position P2, the end surface of the head 21 on the other side in the width direction and the plurality of ink nozzles 211 are arranged in the retreat area A2. That is, the head 21 is partially arranged in the opening 61 provided in the partition wall 60.

As shown in FIG. 6, when moving the head 21 from the printing position P1 to the retracted position P2, the head moving mechanism 22 raises the head 21 from the printing position P1 to the first intermediate position P3, and then moves to the first intermediate position. It is moved from P3 to the second intermediate position P4 to the other side in the width direction, and is lowered from the second intermediate position P4 to the retracted position P2.

When moving the head 21 from the retracted position P2 to the printing position P1, the head moving mechanism 22 raises the head 21 from the retracted position P2 to the second intermediate position P4, and moves from the second intermediate position P4 to the first intermediate position P3. To one side in the width direction, and is lowered from the first intermediate position P3 to the printing position P1.

The cap 23 is a substantially rectangular parallelepiped housing with an open top surface. The cap 23 is fixed at a predetermined position in the retreat area A2. The cap 23 covers the plurality of ink nozzles 211 of the head 21 arranged at the retreat position P2 in the retreat area A2. More specifically, when the head 21 is arranged at the retracted position P2, the peripheral portion of the lower surface of the head 21 located outside the plurality of ink nozzles 211 contacts the upper edge of the cap 23. As a result, the plurality of ink nozzles 211 fit inside the cap 23. Accordingly, by covering the ink nozzles 211 with the cap 23 while the head 21 is not used, it is possible to prevent the ink in the ink nozzles 211 from drying.

In the present embodiment, the cap 23 is provided with the cleaning unit 24. The cleaning unit 24 is a unit for cleaning the plurality of ink nozzles 211 of the head 21. The cleaning unit 24 discharges the cleaning liquid from a cleaning nozzle (not shown) toward the plurality of ink nozzles 211 of the head 21 inside the cap 23. By cleaning the plurality of ink nozzles 211 by the cleaning unit 24, it is possible to remove the fine powder adhering to the ink nozzles 211 in the printing area A1. The cap 23 may not be provided with the cleaning unit 24.

Next, the structure of the shutter mechanism 62 will be described with reference to FIGS. 7 to 10. FIG. 7 is a plan view of the shutter mechanism 62 as viewed in the width direction from the retreat area A2 side. In FIG. 7, the opening 61 of the partition wall 60 is indicated by a chain double-dashed line. FIG. 8 is a partial cross-sectional view of the partition wall 60, the shutter mechanism 62, and the head 21. FIG. 9 is a cross-sectional view of the shutter mechanism 62. FIG. 10 is an exploded perspective view of the shutter 72.

As shown in FIGS. 7 and 8, the shutter mechanism 62 is fixed to the other side of the partition wall 60 in the width direction and attached so as to cover the opening 61. The shutter mechanism 62 has five shutter guides 71 and four shutters 72.

The shutter guides 71 extend in the vertical direction on both sides of each shutter 72. As shown in FIG. 7, the five shutter guides 71 are arranged at intervals in the transport direction. As shown in FIG. 9, the shutter guide 71 has a groove on its side surface into which the side end of the shutter 72 is inserted. As a result, the shutter guide 71 holds the shutter 72 slidably in the vertical direction. That is, the shutter 72 is movable in the vertical direction with respect to the partition wall 60.

As shown in FIG. 7, the shutter guide 71 of the present embodiment is provided with a stopper 711 at the lower end thereof for preventing the shutter 72 from falling downward. However, the shutter guide 71 may not have the stopper 711.

Each of the shutters 72 has a head through hole 720 through which the head 21 can pass. When the head 21 is inserted into the head through hole 720, the upper edge of the head through hole 720 of the shutter 72 is placed on the upper surface of the head 21. As a result, the weight of the shutter 72 is applied to the upper surface of the head 21. That is, the shutter 72 is supported by the upper surface of the head 21.

When the head 21 moves upward, the shutter 72 is pushed by the upper surface of the head 21 and moves upward according to the head 21. When the head 21 moves downward, the shutter 72 moves downward according to the head 21 due to gravity. Therefore, the upper edge of the head through hole 720 is always in contact with the upper surface of the head 21. Thus, the vertical position of the shutter 72 changes according to the vertical position of the head 21.

Here, the position of the shutter 72 when the head 21 is arranged at the printing position P1 and the retreat position P2 is the lower position Q1, and the shutter when the head 21 is arranged at the first intermediate position P3 and the second intermediate position P4. The position of 72 is referred to as the upper position Q2. The shutter 72 moves vertically between the lower position Q1 and the upper position Q2. As shown in FIG. 7, even when the shutter 72 is arranged at the lower position Q1, the upper end portion of the shutter 72 is arranged above the upper end portion of the opening 61. Further, even when the shutter 72 is arranged at the upper position Q2, the lower end portion of the shutter 72 is arranged below the lower end portion of the opening 61. Therefore, the opening 61 of the partition wall 60 is opened by the shutter guide 71 and the shutter 72 regardless of whether the shutter 72 is arranged at the lower position Q1 or the upper position Q2. Is covered.

In the tablet printing apparatus 1, as described above, the head 21 moves within the range where the head 21 does not come off from the head through hole 720 of the shutter 72. Therefore, the communication area between the print area A1 and the retreat area A2 is only the gap between the head through hole 720 of the shutter 72 and the head 21. As a result, the gap between the print area A1 and the retreat area A2 can be minimized. As a result, it is possible to suppress the fine powder from entering the retreat area A2. Further, it is possible to prevent fine powder from adhering to the plurality of ink nozzles 211 of the head 21 in the retreat area A2.

The shutter 72 of the present embodiment is composed of a first member 81, a second member 82, and a seal member 83, as shown in FIGS. 9 and 10. The seal member 83 is made of a material having elasticity. As shown in FIG. 9, the seal member 83 is held between the first member 81 and the second member 82 by being sandwiched between the first member 81 and the second member 82. The first member 81 and the second member 82 may be adhesively fixed, or may be fixed by a fixing tool.

As shown in FIG. 10, the first member 81, the second member 82, and the seal member 83 have a first through hole 810, a second through hole 820, and a third through hole 830, respectively. The first through hole 810 and the second through hole 820 form the head through hole 720 of the shutter 72. The size and shape of the first through hole 810 and the second through hole 820 are the same. The third through hole 830 is slightly smaller than the first through hole 810 and the second through hole 820. Therefore, the inner edge portion of the seal member 83 is arranged slightly inside the edge portion of the head through hole 720 of the shutter 72.

By disposing the seal member 83 at the edge portion of the head through hole 720, when the head 21 is disposed inside the head through hole 720, the gap between the head 21 and the edge portion of the head through hole 720 is provided. The seal member 83 seals the gap. As described above, the contact of the head 21 with the seal member 83 suppresses the intrusion of fine powder from the printing area A1 to the retreat area A2 through the gap between the head 21 and the edge of the head through hole 720. To be done.

The position of the shutter 72 in the width direction does not change. Therefore, when the head 21 moves in the width direction, the surface of the head 21 slides while contacting the seal member 83. As a result, even when the head 21 moves, the seal member 83 seals the gap between the head 21 and the edge of the head through hole 720. Therefore, when the head 21 is moved, it is possible to suppress the intrusion of fine powder from the printing area A1 to the retreat area A2 via the gap.

In the present embodiment, the seal member 83 is arranged on the entire circumference including the upper portion, the lower portion and the side portion of the edge portion of the head through hole 720. Then, the seal member 83 and the head 21 are in contact with each other over the entire circumference of the edge portion of the head through hole 720.

On the other hand, in the present embodiment, a cover 212 is attached to the lower surface of the head 21, as shown in FIGS. 3 and 8. The cover 212 has a hole 213 at a position overlapping the plurality of ink nozzles 211. Therefore, the plurality of ink nozzles 211 are exposed in the holes 213.

The lower surface of the cover 212 is arranged below the lower end of the ink nozzle 211. Therefore, even when the edge of the head through hole 720 of the shutter 72 contacts the lower surface of the cover 212, the ink nozzle 211 does not contact. Therefore, damage to the ink nozzles 211 due to contact is suppressed.

Note that, in the present embodiment, the seal member 83 is arranged on the entire circumference of the edge of the head through hole 720, but the present invention is not limited to this. The seal member 83 may be arranged only in a part of the head through hole 720. For example, the head 21 does not have the cover 212, and there may be a gap between the lower surface of the head 21 and the edge of the head through hole 720. In that case, the seal member 83 may not be disposed below the head through hole 720.

Also, instead of attaching the cover 212 to the lower surface of the head 21, a plurality of ink nozzles 211 may be arranged inside the recess provided in the lower surface of the head 21. In this way, the lower end of the ink nozzle 211 is arranged above the lower surface of the head 21. Therefore, even when the edge portion of the head through hole 720 contacts the lower surface of the head 21, it does not contact the ink nozzle 211. Therefore, damage to the ink nozzles 211 due to contact is suppressed.

<3. Modification>
Although the main embodiments of the present invention have been described above, the present invention is not limited to the above embodiments.

In the above-described embodiment, the position of the cap 23 is fixed, and the head 21 descends to bring the upper edge of the cap 23 into contact with the lower surface of the head 21. However, the cap 23 may be provided with a vertical movement mechanism and the cap 23 may be lifted to bring the upper edge of the cap 23 into contact with the lower surface of the head 21.

Further, in the above embodiment, the printing unit 20 was provided with the four heads 21. A shutter 72 is provided for each of the four heads 21. However, the number of heads 21 included in the printing unit 20 may be 1 to 3, or 5 or more. Also, the number of shutters 72 is not limited to the above example. Further, the tablet printing apparatus 1 may include a printing unit that prints on the front surface of the tablet 9 and a printing unit that prints on the back surface of the tablet 9.

The “tablets” to be treated in the present invention include, for example, plain tablets, orally disintegrating tablets (OD tablets), film-coated tablets (FC tablets), sugar-coated tablets, scored tablets, etc., but not necessarily tablets as pharmaceuticals. It is not limited to. The tablet printing apparatus of the present invention may print on tablets such as health foods and tablet confections such as ramunes.

Further, the detailed configuration of the tablet printing apparatus 1 may be different from the drawings of the present application. Further, the respective elements appearing in the above-described embodiments and modifications may be appropriately combined within a range where no contradiction occurs.

1 Tablet Printing Device 9 Tablets 10 Tablet Conveying Mechanism 20 Printing Section 21 Head 22 Head Moving Mechanism 23 Cap 60 Partition Wall 61 Opening 62 Shutter Mechanism 71 Shutter Guide 72 Shutter 83 Sealing Member 211 Ink Nozzle 212 Cover 213 Hole 720 Head Through Hole A1 Printing area A2 Evacuation area P1 Printing position P2 Evacuation position

Claims

An inkjet type tablet printing device,
A head having a lower surface on which a plurality of ink nozzles for ejecting ink droplets are arranged;
A transport mechanism that transports tablets, which are print targets, in the transport direction,
A partition for partitioning a printing space in which the transport mechanism is arranged and a retreat space,
A shutter provided in the partition wall and having a through hole in which the head is arranged,
A moving mechanism that moves the head at least in the width direction between the printing position and the retracted position,
A cap that covers the ink nozzles of the head at the retracted position,
Have
At the printing position, the end surface on the one side in the width direction of the head and the ink nozzle are arranged in the printing space, and the end surface on the other side in the width direction of the head is arranged in the retreat space,
At the retracted position, the end surface of the head in the width direction on one side is arranged in the printing space, and the end surface of the head on the other side in the width direction and the ink nozzle are arranged in the retracted space.
The tablet printing apparatus according to claim 1, wherein
The shutter is
A seal member arranged at least at a part of the edge of the through hole,
The head contacts at least a part of the seal member at the printing position and the retracted position,
The tablet printing apparatus, wherein the head contacts at least a part of the sealing member even while the moving mechanism moves the head between the printing position and the retracted position.
The tablet printing apparatus according to claim 2, wherein
The tablet printing apparatus, wherein the sealing member is arranged at least on an upper portion and a side portion of an edge portion of the rectangular through hole.
The tablet printing device according to any one of claims 1 to 3,
The moving mechanism is capable of moving the head in the width direction and the vertical direction,
The tablet printing device, wherein the shutter is movable in the vertical direction with respect to the partition wall.
The tablet printing apparatus according to claim 4, wherein
The partition wall is
The tablet printing apparatus further comprising shutter guides extending in the vertical direction on both sides of the shutter, the shutter guide having grooves for accommodating the side ends of the shutter.
The tablet printing apparatus according to any one of claims 1 to 5,
The head is
A cover attached to the lower surface,
The tablet printing apparatus, wherein the cover has a hole through which the ink nozzle is exposed.
The tablet printing apparatus according to any one of claims 1 to 5,
The tablet printing apparatus, wherein the plurality of ink nozzles are arranged inside a recess provided on the lower surface.