JP6817720B2 - Tablet printing device - Google Patents

Description

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

Letters 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 there is a problem that the engraving has low visibility. In particular, in recent years, the types of tablets have been diversified due to the spread of generic drugs. For this reason, in order to make it easier to identify tablets, a technique for clearly printing on the surface of tablets by an inkjet method has attracted attention.

Patent Documents 1 and 2 describe examples of conventional devices that print on paper by an inkjet method.

JP-A-2009-107221 JP-A-2009-107268

In an inkjet tablet printing apparatus, while conveying a tablet, ink droplets (hereinafter, simply referred to as “ink droplets”) are ejected from a plurality of nozzles provided on the ejection surface of the head toward the tablet. However, when the tablet is transported, the fine powder of the tablet is scattered around the transport path. If the fine powder of the tablet adheres to the ejection surface of the head, it becomes difficult to accurately eject ink droplets from the nozzle. That is, in a printing apparatus for tablets, there is a peculiar problem that the accuracy of ejecting ink droplets tends to decrease due to the fine powder of tablets.

In order to remove the fine powder of the tablet from the discharge surface of the head, for example, it is conceivable to wipe off the fine powder adhering to the discharge surface with a flexible plate-shaped blade. However, if the blade is slid while the fine powder is attached to the lower surface of the head, the lower surface of the head may be damaged by rubbing against the fine powder. In addition, since fine powder adheres to the blade, it is necessary to clean the blade itself.

Further, as one method for increasing the efficiency of removing fine powder, it is conceivable to widen the tip portion of the blade. However, when the blade is not used, if the tip of the blade is stored in a bent state, the blade is gradually deformed. When the blade is deformed, the contact area of the blade with respect to the discharge surface is reduced, and the effect of wiping with the blade may not be sufficiently obtained.

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 capable of efficiently removing fine powder of tablets adhering to the ejection surface of a head.

In order to solve the above problems, the first invention of the present application is a tablet printing device that prints on the surface of a tablet, and has a head having an ejection surface in which a plurality of ink nozzles for ejecting ink droplets are arranged, and the head. The cleaning unit includes a cleaning unit for cleaning the discharge surface, a cap for covering the discharge surface, a cleaning nozzle for discharging the cleaning liquid to the discharge surface, and a blade for wiping the cleaning liquid adhering to the discharge surface. The cleaning nozzle and the blade are provided inside the cap, and the cleaning nozzle has a plurality of first discharge ports for discharging the cleaning liquid toward the discharge surface, and the cleaning liquid toward the blade. The cleaning nozzle has a second discharge port for discharging the cleaning liquid, and the cleaning nozzle directly discharges the cleaning liquid to the discharge surface and the blade.

The second invention of the present invention is the tablet printing apparatus of the first invention, in which the cleaning unit is placed between a storage position in which the blade is housed in the cap and an upright position protruding from the cap. It further has a blade moving mechanism for moving.

A third aspect of the present invention is the tablet printing apparatus of the second invention, wherein the blade has a tip portion in contact with the discharge surface, and a pair of side ends of the tip portion are inner edges of the cap. Located on the outside.

The fourth invention of the present application is the tablet printing apparatus of the third invention, in which the cap has a blade storage hole for accommodating the pair of side ends of the tip.

The fifth invention of the present application is the tablet printing apparatus of any one of the second to fourth inventions, and the blade is stored in an inclined posture with respect to a horizontal plane at the storage position.

The sixth invention of the present application is the tablet printing apparatus of any one of the first to fifth inventions, and the cleaning nozzle is a tubular nozzle extending along the long side of the discharge surface.

Seventh invention of the present application relates to a tablet printing apparatus according to any one invention of the first invention to the sixth invention, before Symbol plurality of the first discharge port is directed obliquely to the ejection surface ..

The eighth invention of the present application is the tablet printing apparatus of any one invention from the first invention to the seventh invention, and the cleaning unit further has a support member for supporting the blade and is connected to the support member. A passage is provided, and the cleaning liquid discharged from the cleaning nozzle is supplied to the blade through the continuous passage.

A ninth invention of the present application is the tablet printing apparatus of the eighth invention, in which the support member has a pair of tapered surfaces whose spacing gradually increases from the communication passage to the blade.

The tenth invention of the present application is the tablet printing apparatus of any one of the first to ninth inventions, which includes a cleaning area in which the cleaning unit is arranged and a printing area in which printing is performed on the tablets. A head moving mechanism for moving the head between the cleaning area and the printing area is provided.

The eleventh invention of the present application is the tablet printing apparatus of the tenth invention, further including a partition wall separating the washing area and the printing area.

The twelfth invention of the present application is a tablet printing apparatus according to any one of the first to eleventh inventions, further including a control unit for operating and controlling the head and the cleaning unit, and the control unit is the control unit. A cleaning liquid supply process for discharging the cleaning liquid from the cleaning nozzle to the discharge surface, and a wipe process for wiping the cleaning liquid adhering to the discharge surface with the blade after the cleaning liquid supply process are sequentially executed.

The thirteenth invention of the present application is the tablet printing apparatus of the twelfth invention, and the control unit intermittently discharges the cleaning liquid from the cleaning nozzle in the cleaning liquid supply process.

The fourteenth invention of the present application is the tablet printing apparatus of the twelfth invention or the thirteenth invention, and the control unit further executes a purging process of ejecting ink from a plurality of the ink nozzles of the head.

The fifteenth invention of the present application is a tablet printing apparatus that prints on the surface of a tablet, and cleans a head having an ejection surface in which a plurality of ink nozzles for ejecting ink droplets are arranged, and the ejection surface of the head. A cleaning unit is provided, and the cleaning unit includes a cap that covers the discharge surface, a blade that wipes off the cleaning liquid adhering to the discharge surface, a storage position in which the blade is housed in the cap, and the cap. It has a blade moving mechanism that moves between a protruding standing position, the blade has a tip that contacts the discharge surface, and a pair of side ends of the tip are the inner edges of the cap. Located on the outer side, the cap has blade storage holes for accommodating the pair of side ends of the tip.

According to the first to fourteenth inventions of the present application, after the cleaning liquid is discharged to the discharge surface of the head, the cleaning liquid adhering to the discharge surface can be wiped off with a blade. As a result, the fine powder of the tablet adhering to the discharge surface can be efficiently removed. In addition, a cleaning nozzle and a blade are provided inside the cap. Therefore, the blade can be cleaned with the cleaning liquid discharged from the cleaning nozzle.

In particular, according to the third invention of the present application, the tip end portion of the blade comes into contact with a region of the discharge surface that is wider than the inner edge of the cap. As a result, the cleaning liquid adhering to the discharge surface can be wiped off more efficiently. In addition, the fine powder of the tablet accumulated near the inner edge of the cap can be wiped off with the tip of the blade. As a result, the efficiency of removing fine powder from the discharge surface can be further improved.

In particular, according to the fourth invention of the present application, the tip of the blade can be stored inside the cap without bending. As a result, the deformation of the blade over time can be suppressed.

In particular, according to the fifth invention of the present application, the blade housed in the cap can be cleaned more efficiently.

In particular, according to the sixth invention of the present application, the cleaning liquid can be supplied over a wide range of the discharge surface.

In particular, according to the seventh invention of the present application, the washing liquid discharged from the first discharge opening can be prevented from entering the ink in the nozzles of the head.

In particular, according to the first invention of the present application, the cleaning liquid can be directly supplied to the blade. As a result, the blade can be cleaned more efficiently.

In particular, according to the eighth invention of the present application, the cleaning liquid can be more efficiently supplied to the surface of the blade.

In particular, according to the ninth invention of the present application, the cleaning liquid can be more efficiently supplied to the surface of the blade.

In particular, according to the tenth invention of the present application, by separating the washing area and the printing area, it is easy to keep the printing area to which the tablets are conveyed in a clean state.

In particular, according to the eleventh invention of the present application, it is easy to keep the printing area where the tablets are conveyed in a cleaner state.

In particular, according to the thirteenth invention of the present application, the fine powder of the tablet adhering to the discharge surface can be washed away more efficiently.

In particular, according to the 14th invention of the present application, clogging of the ink nozzle can be eliminated.

Further, according to the fifteenth invention of the present application, the tip end portion of the blade comes into contact with a region of the discharge surface wider than the inner edge of the cap. As a result, the cleaning liquid adhering to the discharge surface can be efficiently wiped off. In addition, it can be stored inside the cap without bending the tip of the blade. As a result, the deformation of the blade over time can be suppressed.

It is a figure which showed the structure of the tablet printing apparatus. It is a partial perspective view of a tablet transport mechanism. It is a bottom view of the head. It is a block diagram which showed the connection between a control part and each part in a tablet printing apparatus. It is a side view of a printing part. It is a perspective view of the cleaning unit viewed from diagonally above. It is a vertical sectional view of a cleaning unit. It is a flowchart which shows the processing procedure at the time of cleaning. It is a vertical sectional view of the cleaning unit at the time of a cleaning liquid supply process. It is a vertical sectional view of a cleaning unit at the time of a wipe process. It is a perspective view of a blade and a support member in a storage position. It is sectional drawing of the cleaning nozzle which concerns on a modification.

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 a "transport direction", and the direction perpendicular to and horizontal to the transport direction is referred to as a "width direction".

<1. Overall configuration 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 device 1 is a device 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 transporting a plurality of tablets 9 which are pharmaceutical products. As shown in FIG. 1, the tablet printing device 1 of the present 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 a plurality of tablets 9 while holding them. The tablet transport mechanism 10 has a pair of pulleys 11 and an annular transport belt 12 spanned between the pair of pulleys 11. The plurality of tablets 9 charged into the tablet printing device 1 are aligned at equal intervals by a carry-in mechanism 51 composed of a vibration feeder, a transport drum, and the like, and are supplied to the outer peripheral surface of the transport belt 12. One of the pair of pulleys 11 is rotated by the power obtained from the transport motor 13. As a result, the transport 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 transport belt 12 rotates.

FIG. 2 is a partial perspective view of the tablet transport mechanism 10. As shown in FIG. 2, the transport belt 12 is provided with a plurality of suction holes 14. The plurality of suction holes 14 are arranged at equal intervals in the transport 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 transport belt 12 becomes 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.

In this way, the tablet transport mechanism 10 transports the plurality of tablets 9 by rotating the transport belt 12 while holding the plurality of tablets 9 in the plurality of 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 transport 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 adsorption of the tablet 9 in the suction hole 14 is released, and the tablet 9 is delivered from the transport belt 12 to the carry-out mechanism 52. The carry-out mechanism 52 carries out the tablet 9 delivered from the transport belt 12 to the outside of the tablet printing device 1 by, for example, another transport belt.

The printing unit 20 is a portion for recording an image on the surface of the tablet 9 transported by the transport 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 row 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) toward the surface of the tablet 9. Then, a multicolor image is recorded on the surface of the tablet 9 by superimposing the monochromatic images formed by each of these colors. As the ink discharged from each head 21, edible ink produced from a raw material approved by the Food Sanitation Law is used.

FIG. 3 is a bottom view of one head 21. In FIG. 3, the transport belt 12 and the plurality of tablets 9 held by the transport belt 12 are shown by an alternate long and short dash line. As shown enlarged in FIG. 3, a plurality of ink nozzles 211 capable of ejecting ink droplets are provided on the ejection surface 210 which is the lower surface of the head 21. In the present 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 ink nozzles 211 are arranged so as to be displaced in the width direction. By arranging the plurality of ink nozzles 211 two-dimensionally in this way, the positions of the ink nozzles 211 in the width direction can be brought close to each other. However, the plurality of ink nozzles 211 may be arranged in a row along the width direction.

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

The drying mechanism 30 is a mechanism for drying the ink adhering to the surface of the tablet 9. The drying mechanism 30 is provided around the transport belt 12 at a position downstream of the printing portion 20 in the transport direction. As the drying mechanism 30, for example, a hot air supply mechanism that blows a heated gas (hot air) toward the tablets 9 transported by the transport belt 12 is used. The ink adhering 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 is a means for controlling 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 device 1. As conceptually shown in FIG. 4, the control unit 40 is composed of 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 a printing process is installed in the storage unit 43.

Further, as shown in FIG. 4, the control unit 40 communicates with the above-mentioned 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. It is connected as possible. Further, the control unit 40 is also communicably connected to the vertical movement mechanism 222, the horizontal movement mechanism 224, the liquid feed pump 733, and the blade movement mechanism 75, 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. About head movement mechanism and cleaning unit>
FIG. 5 is a side view of the printing unit 20 as viewed from the position of the white arrow V in FIG. As shown in FIG. 5, the internal space of the tablet printing apparatus 1 is divided into a printing area A1 and a cleaning area A2. The printing area A1 is an area for printing on the tablets 9 while transporting the tablets 9 by the tablet transport mechanism 10 described above. The cleaning area A2 is an area in which the head 21 is kept on standby before or after printing and the discharge surface 210 of the head 21 is cleaned. A partition wall 60 that separates both areas is provided between the printing area A1 and the cleaning area A2. The partition wall 60 extends parallel to the transport direction of the tablet 9 and perpendicular to the horizontal plane.

As described above, the printing unit 20 has four heads 21. Further, as shown in FIG. 5, the printing unit 20 has a head moving mechanism 22 and a cleaning unit 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 cleaning units 23 corresponding to each head 21.

The head moving mechanism 22 is a mechanism for moving the head 21 between the printing area A1 and the cleaning area A2. The head moving mechanism 22 of the present embodiment includes 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 a direction parallel to the long side of the discharge surface 210 (hereinafter referred to as "front-rear direction"). The head 21 is fixed to the tip of the arm 221. 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, as shown by the arrow D1 in FIG.

The vertical movement mechanism 222 is located in the cleaning area A2 between at least two height positions, that is, the lowering position shown by the solid line in FIG. 5 and the rising position shown by the alternate long and short dash line in FIG. Move the head 21 up and down. In the lowered position, the discharge surface 210 of the head 21 comes into contact with the upper end edge of the cap 71, which will be described later. In the raised position, the discharge surface 210 of the head 21 is separated upward from the cap 71.

The vertical movement mechanism 222 is supported by the movement stage 223. The horizontal movement mechanism 224 moves the movement stage 223 in the front-rear direction. As a result, as shown by the arrow D2 in FIG. 5, the moving stage 223, the vertical moving mechanism 222, the arm 221 and the head 21 are integrally moved in the front-rear direction. At this time, the head 21 and the arm 221 pass through the opening 61 provided in the partition wall 60. The opening 61 may be open at all times, or may be open only while the head 21 and arm 221 pass through.

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 other mechanisms such as a linear motor and an air cylinder.

The cleaning unit 23 is a unit for cleaning the discharge surface 210 of the head 21 in the cleaning area A2. FIG. 6 is a perspective view of the cleaning unit 23 viewed from diagonally above. FIG. 7 is a vertical cross-sectional view of the cleaning unit 23. As shown in FIGS. 5 to 7, the cleaning unit 23 includes a cap 71, a cleaning nozzle 72, a cleaning liquid supply unit 73, a blade 74, and a blade moving mechanism 75.

The cap 71 is a substantially rectangular parallelepiped housing with an open upper surface. The cap 71 is fixed at a predetermined position in the cleaning area A2. When cleaning the discharge surface 210 of the head 21, the head 21 retracted to the cleaning area A2 is moved to the lowered position by the vertical movement mechanism 222. As a result, the discharge surface 210 of the head 21 comes into contact with the rectangular upper end edge of the cap 71. As a result, the area other than the peripheral edge of the discharge surface 210 of the head 21 is covered with the cap 71. The plurality of ink nozzles 211 provided on the ejection surface 210 of the head 21 all fit inside the rectangular upper end edge of the cap 71.

The cleaning nozzle 72 is a member for discharging the cleaning liquid toward the discharge surface 210 of the head 21. The cleaning nozzle 72 is provided inside the cap 71. In the present embodiment, a straight tubular pipe nozzle extending in the front-rear direction is used for the cleaning nozzle 72. If the pipe nozzle is used, the cleaning liquid can be supplied to the discharge surface 210 of the head 21 over a wide range in the front-rear direction. However, the shape of the cleaning nozzle 72 may be another shape such as a flat plate. A plurality of first discharge ports 721 are provided on the surface of the cleaning nozzle 72. The plurality of first discharge ports 721 are arranged at equal intervals in the front-rear direction. Further, each first discharge port 721 is opened toward the discharge surface 210 of the head 21.

Further, the cleaning nozzle 72 of the present embodiment has a second discharge port 722 at the tip of the blade 74 in the front-rear direction. The second discharge port 722 is open toward the blade 74 at the storage position described later. As described above, the cleaning nozzle 72 of the present embodiment has a first discharge port 721 and a second discharge port 722. As a result, the cleaning liquid can be directly discharged to the discharge surface 210 and the blade 74 of the head 21.

The cleaning liquid supply unit 73 is a mechanism for supplying the cleaning liquid to the cleaning nozzle 72. As shown in FIG. 5, the cleaning liquid supply unit 73 includes a cleaning liquid supply source 731, a liquid feeding pipe 732, and a liquid feeding pump 733. The cleaning liquid supply source 731 stores the cleaning liquid before supply. For example, pure water is used as the cleaning liquid. The liquid feed pipe 732 connects the cleaning liquid supply source 731 and the cleaning nozzle 72 in a flow path. The liquid feed pump 733 is provided on the path of the liquid feed pipe 732. The liquid feed pump 733 operates based on a command from the control unit 40, and forms a liquid flow toward the cleaning nozzle 72 side in the liquid feed pipe 732.

When the liquid feed pump 733 is driven, the cleaning liquid is supplied from the cleaning liquid supply source 731 to the cleaning nozzle 72 through the liquid feeding pipe 732. Then, the cleaning liquid is discharged from the plurality of first discharge ports 721 of the cleaning nozzle 72 toward the discharge surface 210 of the head 21, and the cleaning liquid is discharged from the second discharge port 722 of the cleaning nozzle 72 toward the blade 74. Will be done. As a result, the fine powder and ink of the tablet 9 adhering to the discharge surface 210 of the head 21 and the surface of the blade 74 are washed away by the cleaning liquid.

The blade 74 is a member for wiping off the cleaning liquid adhering to the discharge surface 210 of the head 21. For the blade 74, for example, a plate-shaped member made of flexible rubber or the like is used. As shown in FIGS. 6 and 7, the blade 74 has a blade base 741 and a blade tip 742. The blade base 741 is supported by a metal support member 743 that is more rigid than the blade 74. The blade tip portion 742 is a portion that comes into contact with the discharge surface 210 of the head 21. The length of the blade tip portion 742 in the left-right direction (vertical and horizontal directions with respect to the front-rear direction; the same applies hereinafter) is longer than the length of the blade base portion 741 in the left-right direction. That is, the blade 74 of the present embodiment has a substantially T-shaped outer shape. The pair of left-right side end portions 744 of the blade tip portion 742 are located outside the inner edge of the cap 71.

The blade moving mechanism 75 is a mechanism for rotating and moving the support member 743 and the blade 74. The blade moving mechanism 75 has, for example, a drive source such as a motor and a power transmission mechanism that transmits the rotational motion of the motor to the support member 743. When the blade moving mechanism 75 is operated, the blade 74 rotates and moves between the storage position shown by the solid line in FIG. 7 and the standing position shown by the alternate long and short dash line in FIG. When the head 21 is lowered to bring the head 21 into contact with the cap 71, the blade 74 is arranged in the storage position. In the storage position, the entire blade 74 is stored inside the cap 71.

On the other hand, when wiping the cleaning liquid with the blade 74, the head 21 is raised to pull the discharge surface 210 of the head 21 away from the cap 71. Then, the blade 74 is rotationally moved from the storage position to the upright position. In the upright position, the blade tip 742 projects upward from the upper edge of the cap 71 and comes into contact with the discharge surface 210 of the head 21. After that, the head 21 in the ascending position is moved in the front-rear direction by the horizontal movement mechanism 224. As a result, the cleaning liquid or the like adhering to the discharge surface 210 of the head 21 is wiped off by the blade tip portion 742.

As described above, the length of the blade tip portion 742 in the left-right direction is larger than the distance between the inner edges of the cap 71 in the left-right direction. Therefore, the blade tip portion 742 comes into contact with a region of the discharge surface 210 of the head 21 that is wider than the inner edge of the cap 71. As a result, the cleaning liquid adhering to the discharge surface 210 can be wiped off more efficiently. Further, in the discharge surface 210 of the head 21, the fine powder of the tablet 9 that has been poured into the cleaning liquid tends to collect in the vicinity of the contact portion with the inner edge of the cap 71. In the present embodiment, the fine powder of the tablet 9 accumulated in the portion can be wiped off by the both end portions 744 of the blade tip portion 742. Thereby, the efficiency of removing fine powder from the discharge surface 210 can be improved.

Further, as shown in FIGS. 6 and 7, the cap 71 of the present embodiment has blade storage holes 711 on the left and right inner side surfaces, respectively. When the blade 74 is arranged in the storage position, the pair of side end portions 744 of the blade tip portion 742 are stored in the pair of blade storage holes 711, respectively. By providing the blade storage hole 711 in the cap 71 in this way, the blade tip portion 742 can be stored inside the cap 71 without bending. Therefore, the deformation of the blade tip portion 742 with time can be suppressed. That is, it is possible to prevent the shape of the blade tip portion 742 when standing up from changing with the passage of time.

<3. About the processing procedure at the time of cleaning ＞
Subsequently, in the tablet printing apparatus 1 described above, an operation when cleaning the discharge surface 210 of the head 21 will be described. FIG. 8 is a flowchart showing a processing procedure at the time of cleaning. FIG. 9 is a vertical cross-sectional view showing the states of steps S2 and S9. FIG. 10 is a vertical cross-sectional view showing the states of steps S5 and S12. The process described below proceeds by the control unit 40 controlling the operation of the above-mentioned vertical movement mechanism 222, horizontal movement mechanism 224, liquid feed pump 733, blade movement mechanism 75, and the like.

When cleaning the discharge surface 210 of the head 21, first, the control unit 40 operates the horizontal movement mechanism 224 to move the head 21 from the print area A1 to the cleaning area A2. Next, the control unit 40 operates the vertical movement mechanism 222 to move the head 21 from the ascending position to the descending position (step S1). When the head 21 reaches the lowered position, the discharge surface 210 of the head 21 comes into contact with the rectangular upper end edge of the cap 71. As a result, the plurality of ink nozzles 211 provided on the ejection surface 210 of the head 21 are covered with the cap 71.

Subsequently, the control unit 40 starts the operation of the liquid feed pump 733. As a result, the cleaning liquid is supplied from the cleaning liquid supply source 731 to the cleaning nozzle 72 through the liquid feeding pipe 732. Then, as shown in FIG. 9, the cleaning liquid is discharged from the plurality of first discharge ports 721 of the cleaning nozzle 72 toward the discharge surface 210 of the head 21 (step S2, cleaning liquid supply process). As a result, the fine powder of the tablet 9 adhering to the discharge surface 210 of the head 21 is washed away by the cleaning liquid. The cleaning liquid after use is discharged to the outside together with the fine powder of the tablet 9 through the drainage port provided on the bottom surface of the cap 71.

In step S2, the liquid feed pump 733 may be continuously driven to continuously discharge the cleaning liquid from the cleaning nozzle 72. Alternatively, the liquid feed pump 733 may be driven intermittently to intermittently discharge the cleaning liquid from the cleaning nozzle 72. By periodically changing the discharge strength of the cleaning liquid as in the case of intermittent discharge, the fine powder of the tablet 9 adhering to the discharge surface 210 can be washed away more efficiently.

The ejection surface 210 of the head 21 is coated with a water-repellent film in order to eject ink droplets with high accuracy. If the blade 74 is slid on the discharge surface 210 with the fine powder of the tablet 9 adhered to the discharge surface 210, the water-repellent film may be damaged by the fine powder and the water-repellent effect may be reduced. However, if the fine powder is removed from the discharge surface 210 with the cleaning liquid as in the present embodiment, damage to the water-repellent film can be suppressed in the wipe treatment of steps S5 and S12 described later.

In step S2, the cleaning liquid is also discharged from the second discharge port 722 of the cleaning nozzle 72. The cleaning liquid discharged from the second discharge port 722 comes into contact with the surface of the blade 74. As a result, the surface of the blade 74 is cleaned. Details of cleaning the blade 74 will be described later.

When a preset time has elapsed after the start of discharging the cleaning liquid, the control unit 40 stops the liquid feeding pump 733. As a result, the discharge of the cleaning liquid from the cleaning nozzle 72 is stopped.

Next, the control unit 40 operates the vertical movement mechanism 222 to move the head 21 from the descending position to the ascending position (step S3). As a result, the discharge surface 210 of the head 21 is separated from the upper end edge of the cap 71. Subsequently, the control unit 40 operates the blade moving mechanism 75 to rotate and move the blade 74 from the storage position to the upright position (step S4). As a result, the blade tip portion 742 is brought into contact with the discharge surface 210 of the head 21.

After that, the control unit 40 operates the horizontal movement mechanism 224 to move the head 21 in the front-rear direction. Specifically, as shown in FIG. 10, the head 21 is moved horizontally toward the print area A1 side. As a result, the blade tip portion 742 slides relative to the discharge surface 210 of the head 21. As a result, the cleaning liquid adhering to the discharge surface 210 of the head 21 is wiped off by the blade tip portion 742 (step S5, wipe process).

When the wipe process is completed, the control unit 40 operates the blade moving mechanism 75 to rotate and move the blade 74 from the standing position to the storage position (step S6). As a result, the entire blade 74 is housed inside the cap 71. Further, the control unit 40 operates the horizontal movement mechanism 224 to move the head 21 to the upper position of the cap 71 again. Then, the control unit 40 operates the vertical movement mechanism 222 to move the head 21 from the ascending position to the descending position (step S7). When the head 21 reaches the lowered position, the discharge surface 210 of the head 21 comes into contact with the rectangular upper end edge of the cap 71. As a result, the plurality of ink nozzles 211 provided on the ejection surface 210 of the head 21 are covered with the cap 71.

Subsequently, the control unit 40 operates the head 21 to continuously eject ink from the plurality of ink nozzles 211 of the head 21 (step S8, purge process). As a result, clogging of ink due to drying or the like is eliminated in each ink nozzle 211. When a preset time elapses after the start of ink ejection, the control unit 40 stops the ink ejection from each ink nozzle 211.

Subsequently, the control unit 40 starts the operation of the liquid feed pump 733. As a result, the cleaning liquid is supplied from the cleaning liquid supply source 731 to the cleaning nozzle 72 through the liquid feeding pipe 732. Then, as shown in FIG. 9, the cleaning liquid is discharged from the plurality of first discharge ports 721 of the cleaning nozzle 72 toward the discharge surface 210 of the head 21 (step S9, cleaning liquid supply process). As a result, the ink adhering to the ejection surface 210 of the head 21 is washed away by the cleaning liquid. The used cleaning liquid is discharged to the outside together with the ink through a drainage port provided on the bottom surface of the cap 71.

In step S9, the cleaning liquid is also discharged from the second discharge port 722 of the cleaning nozzle 72. The cleaning liquid discharged from the second discharge port 722 comes into contact with the surface of the blade 74. As a result, the surface of the blade 74 is cleaned. Details of cleaning the blade 74 will be described later.

When a preset time has elapsed after the start of discharging the cleaning liquid, the control unit 40 stops the liquid feeding pump 733. As a result, the discharge of the cleaning liquid from the cleaning nozzle 72 is stopped.

Next, the control unit 40 operates the vertical movement mechanism 222 to move the head 21 from the descending position to the ascending position (step S10). As a result, the discharge surface 210 of the head 21 is separated from the upper end edge of the cap 71. Subsequently, the control unit 40 operates the blade moving mechanism 75 to rotate and move the blade 74 from the storage position to the upright position (step S11). As a result, the blade tip portion 742 is brought into contact with the discharge surface 210 of the head 21.

After that, the control unit 40 operates the horizontal movement mechanism 224 to move the head 21 in the front-rear direction. Specifically, as shown in FIG. 10, the head 21 is moved horizontally toward the print area A1 side. As a result, the blade tip portion 742 slides relative to the discharge surface 210 of the head 21. As a result, the cleaning liquid adhering to the discharge surface 210 of the head 21 is wiped off by the blade tip portion 742 (step S12, wipe process).

When the wipe process is completed, the control unit 40 operates the blade moving mechanism 75 to rotate and move the blade 74 from the standing position to the storage position (step S13). As a result, the entire blade 74 is housed inside the cap 71. Further, the control unit 40 operates the horizontal movement mechanism 224 to move the head 21 to the upper position of the cap 71 again. Then, the control unit 40 operates the vertical movement mechanism 222 to move the head 21 from the ascending position to the descending position (step S14). When the head 21 reaches the lowered position, the discharge surface 210 of the head 21 comes into contact with the rectangular upper end edge of the cap 71. As a result, the plurality of ink nozzles 211 provided on the ejection surface 210 of the head 21 are covered with the cap 71.

As described above, in the cleaning unit 23 of the present embodiment, after the cleaning liquid is discharged to the discharge surface 210 of the head 21, the cleaning liquid adhering to the discharge surface 210 can be wiped off by the blade 74. As a result, the fine powder of the tablet 9 adhering to the discharge surface 210 can be efficiently removed. In particular, when the tablet 9 conveyed in the tablet printing apparatus 1 is formed by compressing powder, fine powder is likely to be generated from the surface of the tablet 9, and the fine powder adheres to the discharge surface 210 of the head 21. Cheap. However, in the tablet printing apparatus 1 of the present embodiment, the fine powder adhering to the discharge surface 210 can be removed by the cleaning unit 23. Therefore, it is possible to suppress poor ejection of ink droplets due to fine powder.

Further, in the tablet printing apparatus 1 of the present embodiment, the printing area A1 on which the tablet 9 is conveyed and the cleaning area A2 for cleaning the discharge surface 210 of the head 21 are separated by a partition wall 60. Therefore, even if dust or mist of cleaning liquid is generated from the head moving mechanism 22 or the cleaning unit 23 arranged in the cleaning area A2, the dust or mist is unlikely to enter the printing area A1. Therefore, it is easy to keep the print area A1 in a clean state with less dust and mist.

<4. About cleaning the blade>
In the tablet printing apparatus 1, the cleaning nozzle 72 and the blade 74 are provided inside the cap 71. In step S2 and step S9 described above, the cleaning liquid is discharged from the cleaning nozzle 72 with the blade 74 housed in the cap 71. Therefore, not only the discharge surface 210 of the head 21 but also the surface of the blade 74 is cleaned by the discharged cleaning liquid. That is, the fine powder and ink of the tablet 9 adhering to the surface of the blade 74 are washed away by the cleaning liquid. Therefore, it is not necessary to separately provide a cleaning nozzle for discharging the cleaning liquid to the discharge surface 210 of the head 21 and a cleaning nozzle for discharging the cleaning liquid on the surface of the blade 74.

In particular, the cleaning nozzle 72 of the present embodiment has a second discharge port 722 that opens toward the blade 74. In step S2 and step S9 described above, the cleaning liquid is directly discharged from the second discharge port 722 toward the surface of the blade 74. As a result, the fine powder and ink of the tablet 9 adhering to the surface of the blade 74 are efficiently washed away.

FIG. 11 is a perspective view of the blade 74 and the support member 743 at the storage position. As shown in FIG. 11, the support member 743 of the present embodiment has a communication passage 745. The cleaning liquid discharged from the second discharge port 722 of the cleaning nozzle 72 is supplied to the surface of the blade 74 through the communication passage 745 as shown by the broken line arrow in FIG. In this way, if the support member 743 is provided with the communication passage 745, the cleaning liquid can be more efficiently supplied to the surface of the blade 74. Therefore, the fine powder and ink of the tablet 9 can be removed more efficiently from the surface of the blade 74.

Further, the support member 743 of the present embodiment has a pair of tapered surfaces 746 between the communication passage 745 and the surface of the blade 74. The distance between the pair of tapered surfaces 746 gradually increases from the communication passage 745 toward the surface of the blade 74. In this way, the spread of the cleaning liquid after passing through the communication passage 745 is less likely to be blocked by the support member 743. Therefore, the cleaning liquid can be more efficiently supplied to a wide range of the surface of the blade 74.

Further, as shown in FIGS. 7, 9, and 11, the blade 74 of the present embodiment is stored in the storage position not in a horizontal posture but in a posture inclined with respect to a horizontal plane. More specifically, of both sides of the blade 74, the surface that comes into contact with the discharge surface 210 during the wipe process is in an inclined posture so as to face the cleaning nozzle 72 side. In this way, the cleaning liquid discharged from the cleaning nozzle 72 can be more efficiently supplied to the easily soiled surface of the blade 74. Further, the supplied cleaning liquid quickly flows downward along the inclination of the blade 74. Therefore, the fine powder and ink of the tablet 9 can be removed more efficiently from the surface of the blade 74.

<5. Modification example>
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 embodiment, the first discharge port 721 of the cleaning nozzle 72 is oriented perpendicular to the discharge surface 210 of the head 21. However, as shown in FIG. 12, the first discharge port 721 may be oriented obliquely with respect to the discharge surface 210 of the head 21. In this way, the cleaning liquid discharged from the first ejection port 721 is less likely to enter the ink nozzle 211. Therefore, it is possible to prevent the cleaning liquid from being mixed with the undischarged ink in the ink nozzle 211.

Further, in the above embodiment, the position of the cap 71 is fixed, and the head 21 is lowered to bring the upper end edge of the cap 71 into contact with the discharge surface 210 of the head 21. However, the cap 71 may be provided with a vertical movement mechanism and the cap 71 may be raised to bring the upper end edge of the cap 71 into contact with the discharge surface 210 of the head 21.

Further, in the above embodiment, the printing unit 20 is provided with four heads 21. A head moving mechanism 22 and a cleaning unit 23 are 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. Further, the number of the head moving mechanism 22 and the cleaning unit 23 is not limited to the above example. Further, the tablet printing device 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.

Further, the "tablet" to be treated in the present invention includes, for example, uncoated tablets, orally disintegrating tablets (OD tablets), film-coated tablets (FC tablets), sugar-coated tablets, secant tablets, etc., but is not necessarily a tablet as a pharmaceutical product. Not limited to. The tablet printing apparatus of the present invention may print on tablets as health foods and tablet confectionery such as ramune.

Further, the detailed configuration of the tablet printing apparatus 1 may be different from each drawing of the present application. Further, the elements appearing in the above-described embodiments and modifications may be appropriately combined as long as there is no contradiction.

1 Tablet printing device 9 Tablets 10 Tablet transfer mechanism 12 Transfer belt 20 Printing unit 21 Head 22 Head movement mechanism 23 Cleaning unit 30 Drying mechanism 40 Control unit 60 Partition 61 Opening 71 Cap 72 Cleaning nozzle 73 Cleaning liquid supply unit 74 Blade 75 Blade movement Mechanism 210 Discharge surface 211 Ink nozzle 221 Arm 222 Vertical movement mechanism 223 Movement stage 224 Horizontal movement mechanism 711 Blade storage hole 721 First discharge port 722 Second discharge port 731 Cleaning liquid supply source 732 Cleaning liquid supply pipe 733 Liquid feed pump 741 Blade base 742 Blade tip 743 Support member 744 Side end 745 Continuous passage 746 Tapered surface A1 Printing area A2 Cleaning area

Claims (15)

A tablet printing device that prints on the surface of tablets.
A head having an ejection surface in which a plurality of ink nozzles for ejecting ink droplets are arranged,
A cleaning unit that cleans the discharge surface of the head and
With
The cleaning unit is
A cap that covers the discharge surface and
A cleaning nozzle that discharges cleaning liquid to the discharge surface,
A blade that wipes off the cleaning liquid adhering to the discharge surface,
Have,
The cleaning nozzle and the blade are provided inside the cap.
The cleaning nozzle
A plurality of first discharge ports for discharging the cleaning liquid toward the discharge surface,
A second discharge port that discharges the cleaning liquid toward the blade,
Have,
The cleaning nozzle is a tablet printing device that directly ejects a cleaning liquid onto the ejection surface and the blade. The tablet printing apparatus according to claim 1.
The cleaning unit is
A tablet printing apparatus further comprising a blade moving mechanism for moving the blade between a storage position housed in the cap and an upright position protruding from the cap. The tablet printing apparatus according to claim 2.
The blade has a tip that comes into contact with the discharge surface.
A tablet printing device in which a pair of side ends of the tip is located outside the inner edge of the cap. The tablet printing apparatus according to claim 3.
The cap
A tablet printing device having a blade storage hole for accommodating the pair of side ends of the tip. The tablet printing apparatus according to any one of claims 2 to 4.
In the storage position, the blade is a tablet printing device that is stored in an inclined posture with respect to a horizontal plane. The tablet printing apparatus according to any one of claims 1 to 5.
The cleaning nozzle is a tablet printing device that is a tubular nozzle extending along a long side of the discharge surface. The tablet printing apparatus according to any one of claims 1 to 6 .
Before SL plurality of first discharge port, the tablet printing apparatus is directed obliquely to the ejection surface. The tablet printing apparatus according to any one of claims 1 to 7 .
The cleaning unit further includes a support member that supports the blade.
A continuous passage is provided in the support member, and a continuous passage is provided.
A tablet printing device in which a cleaning liquid discharged from the cleaning nozzle is supplied to the blade through the communication passage. The tablet printing apparatus according to claim 8 .
The support member is a tablet printing device having a pair of tapered surfaces whose intervals gradually increase from the communication passage toward the blade. The tablet printing apparatus according to any one of claims 1 to 9 .
The cleaning area where the cleaning unit is located and
The printing area where the tablets are printed and
A head moving mechanism for moving the head between the cleaning area and the printing area,
A tablet printing device comprising. The tablet printing apparatus according to claim 10 .
A tablet printing apparatus further comprising a partition wall that separates the cleaning area and the printing area. The tablet printing apparatus according to any one of claims 1 to 11 .
A control unit that controls the operation of the head and the cleaning unit is further provided.
The control unit
A cleaning liquid supply process for discharging the cleaning liquid from the cleaning nozzle to the discharge surface, and
After the cleaning liquid supply treatment, a wipe treatment in which the cleaning liquid adhering to the discharge surface is wiped off with the blade,
A tablet printing device that sequentially executes. The tablet printing apparatus according to claim 12 .
The control unit is a tablet printing device that intermittently discharges the cleaning liquid from the cleaning nozzle in the cleaning liquid supply process. The tablet printing apparatus according to claim 12 or 13 .
The control unit
A tablet printing apparatus that further executes a purge process of ejecting ink from a plurality of the ink nozzles of the head after the wipe process. A tablet printing device that prints on the surface of tablets.
A head having an ejection surface in which a plurality of ink nozzles for ejecting ink droplets are arranged,
A cleaning unit that cleans the discharge surface of the head and
With
The cleaning unit is
A cap that covers the discharge surface and
A blade that wipes off the cleaning liquid adhering to the discharge surface,
It has a blade moving mechanism for moving the blade between a storage position housed in the cap and an upright position protruding from the cap.
The blade has a tip that comes into contact with the discharge surface.
The pair of side ends of the tip are located outside the inner edge of the cap.
The cap
A tablet printing device having a blade storage hole for accommodating the pair of side ends of the tip.

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