WO2017199602A1 - Drying unit, tablet printing device, and drying method - Google Patents

Abstract

A drying unit (30) of this tablet printing device is provided with: a blower fan (81) which forms a flow of a gas; heaters (82) for heating the gas; and a plurality of blow-out ports (31) through which the heated gas is blown out towards tablets. Each of the plurality of blow-out ports (31) is provided in a position facing the conveyed tablets (9). Accordingly, the heated gas can be prevented from laterally hitting the tablets (9) being conveyed. Therefore, the gas can be made to hit the tablets forcefully, while preventing the tablets (9) being conveyed from being blown off. As a result, ink adhered to the surfaces of the tablets (9) can be dried efficiently.

Description

Drying unit, tablet printing apparatus, and drying method

The present invention relates to a drying unit for drying ink adhering to the surface of a tablet, a tablet printing apparatus including the drying unit, and a drying method.

* Characters and codes for identifying products are printed on the surface of tablets, which is a form of pharmaceuticals. Such characters and codes may be printed by engraving, but the engraving has a problem of 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 easy to identify a tablet, a technique for performing clear printing on the surface of the tablet by an ink jet method has attracted attention.

In an inkjet tablet printing apparatus, ink droplets (hereinafter simply referred to as “ink droplets”) are ejected from a plurality of nozzles toward a tablet while transporting the tablet. Thereafter, the ink adhering to the surface of the tablet is dried to fix the ink to the surface of the tablet. For example, the ink is dried by spraying a heated gas onto the surface of the ink.

A conventional tablet printing apparatus provided with a mechanism for drying ink is described in Patent Document 1, for example.

Japanese Patent Laid-Open No. 06-143539

In order to efficiently dry the ink adhering to the tablet, it is necessary to increase the temperature of the gas sprayed on the tablet or to increase the amount of gas sprayed per unit time (air volume). However, there is a certain limit to the temperature of the gas that can be sprayed onto the tablet. In addition, if the air volume is increased and gas is strongly applied to the tablets, the tablets being transported may be blown off.

The present invention has been made in view of such circumstances, and in an inkjet tablet printing apparatus, the tablet being transported is restrained from being blown away, and a gas is strongly applied to the tablet to adhere to the surface of the tablet. It is an object of the present invention to provide a technique capable of efficiently drying the obtained ink.

In order to solve the above problems, a first invention of the present application is a drying unit that dries ink attached to the surfaces of a plurality of tablets to be conveyed, and a blower fan that forms a gas flow, and a heater that heats the gas And a plurality of air outlets that blow out the heated gas toward the tablets, and each of the air outlets is provided at a position facing the tablets to be conveyed.

2nd invention of this application is a drying unit of 1st invention, Comprising: These tablets are conveyed in the state aligned in the width direction orthogonal to a conveyance direction, Each of these air outlets is a tablet, respectively. It is provided at the corresponding position in the width direction.

The third invention of the present application is the drying unit of the second invention, wherein the plurality of outlets blow out gas perpendicularly to the transport direction and the width direction, respectively.

4th invention of this application is a drying unit of 3rd invention, Comprising: It further has the baffle plate provided in each of the said several blower outlet.

5th invention of this application is a drying unit of any one invention from 2nd invention to 4th invention, Comprising: From the several suction port which attracts | sucks the gas blown out from the said blower outlet, From the said several suction port A circulation duct for sending gas to the blower fan.

6th invention of this application is a drying unit of 5th invention, Comprising: The said blower outlet and the said suction port are alternately arranged in the said width direction.

7th invention of this application is a drying unit of 5th invention or 6th invention, Comprising: The supply duct which sends gas to the said several blower outlet from the said ventilation fan, and the exterior cover which covers the said supply duct The circulation duct is formed between the supply duct and the exterior cover.

The eighth invention of the present application is the drying unit according to the seventh invention, wherein the exterior cover has an exhaust part for discharging gas to the outside and an outside air introduction part for taking in gas from the outside.

The ninth invention of the present application is the drying unit according to any one of the first to eighth inventions, wherein the hot air nozzle portion having the plurality of outlets is detachable.

A tenth invention of the present application is the drying unit according to any one of the first to ninth inventions, further comprising a flow dividing plate that divides a space between the heater and the plurality of outlets into a plurality of flow paths. Have.

The eleventh invention of the present application is the drying unit according to any one of the first invention to the tenth invention, and further includes a filter that removes dust from the gas toward the outlet.

The twelfth aspect of the present invention is the drying unit according to any one of the first to eleventh aspects, wherein the blower fan is disposed at a position lower than the heater.

The thirteenth invention of the present application is the drying unit according to any one of the first to twelfth inventions, wherein the blower fan is a counter-rotating fan.

14th invention of this application is a drying unit of any one invention from 1st invention to 13th invention, Comprising: The said ventilation fan and the said heater can each adjust output.

A fifteenth aspect of the present invention is a tablet printing apparatus that performs printing on the surface of a tablet, a transport mechanism that transports a plurality of tablets, a head that ejects ink droplets onto the surface of the tablet transported by the transport mechanism, A drying unit according to any one of the first to fourteenth inventions.

A sixteenth aspect of the present invention is a tablet printing apparatus that performs printing on the surface of a tablet, a transport mechanism that transports a plurality of tablets, a head that ejects ink droplets onto the surface of the tablet transported by the transport mechanism, A drying unit according to any one of the fifth to eighth aspects of the present invention, and a control unit that controls the transport mechanism, the head, and the drying unit, wherein the transport mechanism has a plurality of suction holes. An annular conveyor belt; a mechanism for rotating the conveyor belt; and a suction mechanism for sucking out gas from a space inside the conveyor belt, and the control unit is configured to operate the suction mechanism when the drying unit is activated. The blower fan and the heater are started in a state where the operation is stopped.

A seventeenth aspect of the present invention is a tablet printing apparatus that performs printing on the surface of a tablet, a transport mechanism that transports a plurality of tablets, a head that ejects ink droplets onto the surface of the tablet transported by the transport mechanism, A drying unit according to any one of the fifth to eighth aspects of the present invention, and a control unit that controls the transport mechanism, the head, and the drying unit, wherein the transport mechanism has a plurality of suction holes. An annular conveyor belt; a mechanism for rotating the conveyor belt; and a suction mechanism for sucking out gas from a space inside the conveyor belt, and the controller is configured to stop the drying unit when the drying unit is stopped. The heater is stopped in a state in which is operated.

An eighteenth invention of the present application is a drying method for drying ink adhering to the surfaces of a plurality of tablets to be conveyed, wherein a) a step of heating the gas, and b) blowing out the heated gas toward the tablets. In step b), gas is blown toward the tablets from a plurality of outlets provided at positions facing the tablets to be conveyed.

According to the first to eighteenth inventions of the present application, it is possible to prevent the heated gas from hitting the tablet sideways against the tablet being conveyed. Therefore, it is possible to strongly apply gas to the tablets while suppressing the tablets being transported from being blown away. As a result, the ink attached to the surface of the tablet can be efficiently dried.

In particular, according to the third invention of the present application, a heated gas can be applied to the tablet being conveyed from directly above. Thereby, it can suppress more that the tablet in conveyance is blown away.

In particular, according to the fourth invention of the present application, the heated gas can be applied to the tablet being conveyed from directly above with higher accuracy.

In particular, according to the fifth aspect of the present invention, the heated gas can be reused. Thereby, the energy required for heating the gas can be reduced. Moreover, since it is difficult for dust to mix from the outside, it is easy to maintain the gas sprayed on the tablet in a clean state.

In particular, according to the sixth invention of the present application, the gas blown out from each outlet can be efficiently sucked into the inlet.

In particular, according to the seventh invention of the present application, a drying unit capable of circulating gas can be formed compactly.

Particularly, according to the eighth invention of the present application, a part of the gas in the circulation duct can be discharged to the outside, and the external gas can be introduced into the circulation duct. Thereby, the humidity of the circulating gas can be reduced.

Particularly, according to the ninth invention of the present application, when there is a specification change such as changing the interval in the width direction of the tablet, it can be replaced with a hot air nozzle part suitable for the changed specification.

In particular, according to the tenth aspect of the present invention, the gas that has passed through the heater can be efficiently guided to a plurality of outlets. Thereby, the difference of the airflow for every blower outlet can be reduced.

In particular, according to the eleventh aspect of the present invention, the gas sprayed onto the tablet can be kept clean. Moreover, the flow of gas can be made uniform to reduce the difference in air volume at each outlet.

In particular, according to the twelfth aspect of the present invention, deterioration of the blower fan due to the heat of the heater can be suppressed.

In particular, according to the thirteenth invention of the present application, an air flow having a high static pressure can be formed. An air flow with a high static pressure is less likely to cause a reduction in air volume due to resistance. Therefore, gas can be blown out strongly from a plurality of outlets.

In particular, according to the sixteenth aspect of the present invention, the temperature of the drying gas can be quickly increased.

In particular, according to the seventeenth aspect of the present invention, the temperature of the gas in the drying unit can be quickly reduced.

It is the figure which showed the structure of the tablet printing apparatus. It is a fragmentary perspective view of a tablet conveyance mechanism. It is a bottom view of a head. It is the block diagram which showed the connection of a control part and each part in a tablet printing apparatus. It is an external appearance perspective view of a drying unit. It is a perspective view of the supply duct in a drying unit. It is a cross-sectional view of the vicinity of the ventilation surface of the drying unit. It is a longitudinal cross-sectional view of the drying unit in the position of the width direction in which a branch nozzle exists. It is a longitudinal cross-sectional view of the drying unit in the position of the width direction where a branch nozzle does not exist. It is the flowchart which showed the preferable starting procedure of the drying unit. It is the flowchart which showed the preferable stop procedure of a drying unit. It is a longitudinal cross-sectional view of the drying unit which concerns on a modification. It is a longitudinal cross-sectional view of the drying unit which concerns on a modification.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, a direction in which a plurality of tablets are transported is referred to as a “transport direction”, and a direction perpendicular 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 apparatus 1 is an apparatus that prints an image 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 medicines. 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 unit 30, and a control unit 40.

The tablet transport mechanism 10 is a mechanism that transports a plurality of tablets 9 while holding them. The tablet transport mechanism 10 includes a pair of pulleys 11 and an annular transport belt 12 that is stretched between the pair of pulleys 11. The plurality of tablets 9 put into the tablet printing apparatus 1 are aligned at equal intervals and supplied to the outer peripheral surface of the conveyor belt 12 by a carry-in mechanism 51 configured by a vibration feeder, a conveyance drum, and the like. One of the pair of pulleys 11 is rotated by power obtained from the conveyance motor 13. Thereby, the conveyance 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 conveyance 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. As shown in FIG. 1, the tablet transport mechanism 10 includes a suction mechanism 15 that sucks out gas from the space inside the transport belt 12. When the suction mechanism 15 is operated, the space inside the conveyor belt 12 becomes a negative pressure lower than the atmospheric pressure. The plurality of tablets 9 are sucked and held in the suction holes 14 by the negative pressure.

Thus, the plurality of tablets 9 are held on the surface of the transport belt 12 in a state of being aligned in the transport direction and the width direction. And the tablet conveyance mechanism 10 conveys the some tablet 9 in a conveyance direction by rotating the conveyance belt 12. FIG. Below the four heads 21 described later, the plurality of tablets 9 are conveyed 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, only the suction holes 14 facing the carry-out mechanism 52 among the plurality of suction holes 14 of the transport belt 12 have a positive pressure higher than the atmospheric pressure. Thereby, the suction 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 unloading mechanism 52 unloads the tablet 9 delivered from the conveyance belt 12 to the outside of the tablet printing apparatus 1 by, for example, another conveyance belt.

The printing unit 20 is a part that records an image on the surface of the tablet 9 conveyed by the conveying belt 12 by an inkjet method. As shown in FIG. 1, the printing unit 20 of the present 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) toward the surface of the tablet 9. Then, a multicolor image is recorded on the surface of the tablet 9 by superimposing single color images formed by these colors. In addition, the edible ink manufactured by the raw material approved by the food hygiene law is used for the ink discharged from each head 21.

FIG. 3 is a bottom view of one head 21. In FIG. 3, the conveyance belt 12 and the plurality of tablets 9 held on the conveyance belt 12 are indicated by a two-dot chain line. As shown in an enlarged manner 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 with their positions shifted in the width direction. As described above, if the plurality of ink nozzles 211 are two-dimensionally arranged, the positions in the width direction of the ink nozzles 211 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 for ejecting ink droplets from the ink nozzle 211, for example, a so-called piezo method is used in which a voltage is applied to a piezo element, which is a piezoelectric element, and the ink in the ink nozzle 211 is pressurized and ejected. . However, the ink droplet ejection method may be a so-called thermal method in which the ink in the ink nozzle 211 is heated and expanded by energizing the heater.

The drying unit 30 is a unit for drying the ink attached to the surface of the tablet 9. The drying unit 30 is provided around the transport belt 12 at a position downstream of the printing unit 20 in the transport direction. In the present embodiment, the drying unit 30 is disposed so as to face a portion of the transport belt 12 that is rotated in an arc shape by the pulley 11. The drying unit 30 blows heated gas (hot air) toward the tablets 9 transported by the transport belt 12. Thereby, water evaporates from the ink adhering to the surface of the tablet 9, and the ink is dried. As a result, the ink is fixed on the surface of the tablet 9. The detailed structure of the drying unit 30 will be described later.

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 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 printing processing is installed in the storage unit 43.

As shown in FIG. 4, the control unit 40 includes the tablet conveyance mechanism 10 (including the conveyance motor 13, the suction mechanism 15, and the blow mechanism 16), the printing unit 20 (including the four heads 21), The drying unit 30 (including a blower fan 81 and a heater 82 to be described later), a carry-in mechanism 51, and a carry-out mechanism 52 are connected so as to be able to communicate with each other. 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, thereby controlling the operation of each unit described above. To do. Thereby, the printing process with respect to the some tablet 9 advances.

<2. About Drying Unit>
Next, the detailed structure of the drying unit 30 will be described. FIG. 5 is an external perspective view of the drying unit 30. FIG. 6 is a perspective view of the supply duct 60 in the drying unit 30. As shown in FIGS. 5 and 6, the drying unit 30 includes a supply duct 60 and an exterior cover 70 that covers the supply duct 60.

The supply duct 60 is a duct for supplying hot air for drying toward the surface of the conveyor belt 12. The supply duct 60 of the present embodiment includes a vertical pipe portion 61, a horizontal pipe portion 62, and a hot air nozzle portion 63. The vertical pipe portion 61 extends upward from a lower end portion having an opening. The horizontal tube portion 62 extends horizontally from the upper end portion of the vertical tube portion 61 toward the hot air nozzle portion 63. The hot air nozzle portion 63 can be attached to and detached from the downstream end portion of the horizontal tube portion 62.

The hot air nozzle part 63 has a plurality of branch nozzles 64 arranged in the width direction. Each branch nozzle 64 has a blowing surface 65 at the downstream end. The blow-out surface 65 is curved in an arc shape along the conveyance path of the tablet 9. The space in the branch nozzle 64 gradually expands up and down as it goes to the blowing surface 65. In addition, each outlet surface 65 is provided with a plurality of inner outlets 66. In the present embodiment, a plurality of inner outlets 66 are vertically arranged in a row on the outlet surface 65 of one branch nozzle 64.

The exterior cover 70 is a housing that houses the supply duct 60 therein. The exterior cover 70 has an arc-shaped ventilation surface 71 that faces the surface of the conveyor belt 12. The ventilation surface 71 covers the plurality of blowing surfaces 65 of the hot air nozzle portion 63 described above. FIG. 7 is a cross-sectional view of the vicinity of the ventilation surface 71. As shown in FIGS. 5 and 7, the ventilation surface 71 is provided with a plurality of outer air outlets 72 and a plurality of suction ports 73. Each of the plurality of outer air outlets 72 is provided at a position overlapping the inner air outlet 66. The plurality of suction ports 73 are respectively provided at positions that do not overlap with the branch nozzle 64. That is, on the ventilation surface 71 of the exterior cover 70, the rows of the outer blowout ports 72 and the rows of the suction ports 73 are alternately arranged in the width direction.

In the present embodiment, the inner outlet 66 and the outer outlet 72 corresponding thereto constitute one outlet 31 for blowing hot air. The drying unit 30 has a plurality of such outlets 31. The plurality of air outlets 31 are respectively provided at positions in the width direction corresponding to the plurality of tablets 9 held on the conveyor belt 12. The intervals in the width direction of the plurality of outlets 31 and the intervals in the width direction of the plurality of tablets 9 held on the transport belt 12 are the same.

FIG. 8 is a longitudinal sectional view of the drying unit 30 at a position in the width direction where the branch nozzle 64 is present. FIG. 9 is a longitudinal sectional view of the drying unit 30 at a position in the width direction where the branch nozzle 64 does not exist. As shown in FIGS. 8 and 9, the drying unit 30 includes a blower fan 81, a heater 82, a filter 83, and a plurality of flow dividing plates 84 inside the supply duct 60.

The blower fan 81 is a mechanism for forming an air flow inside the drying unit 30. The blower fan 81 is housed inside the vertical tube portion 61. In this embodiment, a counter-rotating fan is used as the blower fan 81. The counter-rotating fan rotates the two impellers 811 and 812 arranged above and below in opposite directions. Thereby, an air current having a high static pressure is formed. The airflow with high static pressure is unlikely to cause a decrease in wind force due to resistance of the heater 82, the filter 83, the plurality of inner outlets 66, the plurality of outer outlets 72, and the like. However, the blower fan 81 may be another type of fan other than the counter-rotating fan.

The heater 82 is a mechanism for heating the gas in the supply duct 60. As the heater 82, for example, an electrothermal heater that generates heat when energized is used. In the present embodiment, three columnar heaters 82 extending in the width direction are accommodated in the horizontal tube portion 62. However, the shape and number of the heaters 82 are not necessarily the same as in the present embodiment.

The blower fan 81 and the heater 82 operate based on a command from the control unit 40. When the blower fan 81 is operated, an air flow is generated from the vertical tube portion 61 through the horizontal tube portion 62 toward the hot air nozzle portion 63. When the heater 82 is operated in this state, the airflow is heated by the heater 82 and becomes hot air. The drying unit 30 blows the hot air toward the tablets 9 on the conveyor belt 12 from the air outlet 31 constituted by the inner air outlet 66 and the outer air outlet 72.

Further, when the blower fan 81 is driven, air is sucked into the supply duct 60 from the space between the supply duct 60 and the exterior cover 70. Therefore, the space between the supply duct 60 and the exterior cover 70 becomes negative pressure. For this reason, the gas blown out from the plurality of air outlets 31 is sucked into the space between the supply duct 60 and the exterior cover 70 through the plurality of suction ports 73. Then, the sucked gas is sucked into the supply duct 60 again. That is, in this embodiment, the space between the supply duct 60 and the exterior cover 70 is the circulation duct 32 that sends gas from the plurality of suction ports 73 to the blower fan 81.

8 and 9, in this embodiment, the blower fan 81 is disposed at a position lower than the heater 82. For this reason, even if the air flow from the blower fan 81 to the heater 82 stops due to a failure of the blower fan 81, the heat of the heater 82 is not easily transmitted to the blower fan 81 side. Therefore, it can suppress that the member which comprises the ventilation fan 81 deteriorates with a heat | fever.

The filter 83 is provided in the horizontal pipe portion 62 at a position downstream of the heater 82. The filter 83 plays a role of removing dust from the gas toward the air outlet 31. When dust such as fine powder of the tablet 9 is contained in the gas sucked into the drying unit 30 from the suction port 73, the dust is removed by being captured by the filter 83. Thereby, the hot air sprayed on the tablet 9 can be maintained in a clean state. Further, the gas flow is made uniform by passing through the filter 83. Thereby, the difference of the airflow for every blower outlet 31 can be reduced.

The plurality of flow dividing plates 84 are members for dividing the space between the filter 83 and the plurality of inner blowout ports 66 into a plurality of flow paths. The plurality of flow dividing plates 84 are arranged vertically in each branch nozzle 64. The hot air that has passed through the heater 82 and the filter 83 flows into the plurality of branch nozzles 64 and branches and flows into the plurality of flow paths by the flow dividing plates 84 in each branch nozzle 64. Thereby, the hot air is efficiently guided to the plurality of inner outlets 66. As a result, the difference in the air volume for each outlet 31 is further reduced.

As described above, the drying unit 30 blows hot air from the plurality of outlets 31 to the plurality of tablets 9 that are conveyed in an aligned state on the conveyor belt 12. Thereby, the ink adhering to the surface of the tablet 9 is dried. In particular, in the drying unit 30, a plurality of air outlets 31 are provided at positions in the width direction corresponding to the tablets 9 on the transport belt 12. That is, each blower outlet 31 is provided in the position which opposes the tablet 9 conveyed. For this reason, it is hard for hot air to hit the width direction with respect to the tablet 9 in conveyance. Therefore, it can suppress that the tablet 9 in conveyance is blown away. Moreover, since the tablet 9 is hard to be blown off from the conveyance belt 12, it is possible to improve the drying performance by strongly applying gas to the tablet 9.

Further, the plurality of air outlets 31 blow hot air perpendicular to the conveyance direction and the width direction of the tablets 9, respectively. For this reason, the hot air which strikes the tablet 9 being conveyed from before and after in the conveyance direction is also reduced. That is, hot air can be applied to each tablet 9 from directly above (a direction perpendicular to the conveyance belt 12). Therefore, it can suppress more that the tablet 9 in conveyance is blown off from the conveyance belt 12. FIG.

Further, as shown in FIG. 8, the branch nozzle 64 of the present embodiment has a plurality of rectifying plates 85. The plurality of rectifying plates 85 extend between the plurality of inner blowout ports 66 in parallel with the direction in which hot air is blown out. By providing such a baffle plate 85, hot air can be more accurately applied to the tablet 9 being conveyed from directly above.

In addition, the drying unit 30 sucks the hot air blown from the blowout port 31 through the suction port 73 into the exterior cover 70 again. Then, the sucked hot air is blown out from the outlet 31 again. If it does in this way, once heated gas can be reused. Therefore, the energy required for heating the gas can be reduced. Moreover, since it is hard to mix dust from the outside, it is easy to maintain the gas sprayed on the tablet 9 in a clean state.

In particular, in the structure of the present embodiment, the circulation duct 32 for sending gas from the suction port 73 to the blower fan 81 is formed between the supply duct 60 and the exterior cover 70. That is, the surface of the supply duct 60 is used as a part of the circulation duct 32. In this way, the entire drying unit 30 can be formed more compactly than when a circulation duct separated from the supply duct 60 is separately provided outside the supply duct 60. Therefore, the external dimensions of the tablet printer 1 can also be reduced.

Further, in the drying unit 30 of the present embodiment, the air outlets 31 and the suction ports 73 are alternately arranged in the width direction. For this reason, the gas blown out from the blowout port 31 can be efficiently sucked by the suction ports 73 adjacent to each other in the width direction of the blowout port 31. Thereby, the circulation efficiency of hot air can be improved.

Further, in the drying unit 30, the hot air nozzle portion 63 having a plurality of inner blowout ports 66 can be attached to and detached from the downstream end portion of the horizontal tube portion 62. For this reason, when the specification of the tablet printing apparatus 1 is changed, the hot air nozzle part 63 suitable for the changed specification can be replaced. For example, when the intervals in the width direction of the plurality of tablets 9 held on the transport belt 12 are changed, the intervals in the width direction of the plurality of inner blowout ports 66 can be changed accordingly. Further, when hot air drying is unnecessary, the hot air nozzle portion 63 can be replaced with one without the inner blowout port 66.

<3. Operation at startup and stop>
FIG. 10 is a flowchart showing a preferable starting procedure of the drying unit 30 in the tablet printing apparatus 1. When starting the drying unit 30, first, the control unit 40 starts the blower fan 81 and the heater 82 of the drying unit 30 (step S1). Thereby, the circulation of the gas in the drying unit 30 is started.

At this time, the control unit 40 stops the suction mechanism 15 of the tablet transport mechanism 10 and keeps the inside of the transport belt 12 at normal pressure. Then, the gas blown out from the plurality of outlets 31 of the drying unit 30 is sucked into the plurality of suction ports 73 of the drying unit 30 without being sucked into the plurality of suction holes 14 of the transport belt 12. Therefore, the gas can be circulated efficiently in the drying unit 30. Thereby, the temperature of the gas for drying can be raised rapidly.

Eventually, when the gas circulating in the drying unit 30 rises to the first target temperature suitable for drying (step S2), the control unit 40 activates the suction mechanism 15 of the tablet transport mechanism 10 (step S3).

FIG. 11 is a flowchart showing a preferable stopping procedure of the drying unit 30 in the tablet printing apparatus 1. When stopping the drying unit 30, first, the control unit 40 stops the heater 82 of the drying unit 30 (step S4). Thereby, the heating of the gas in the drying unit 30 is stopped.

At this time, the controller 40 keeps the suction mechanism 15 of the tablet transport mechanism 10 in operation. For this reason, some of the gas blown out from the plurality of outlets 31 of the drying unit 30 is sucked into the plurality of suction holes 14 of the transport belt 12. Thereby, in the drying unit 30, the temperature of the circulating gas can be rapidly reduced.

Eventually, when the gas circulating in the drying unit 30 decreases to the second target temperature close to the environmental temperature (step S5), the control unit 40 includes the suction mechanism 15 of the tablet transport mechanism 10 and the blower fan 81 of the drying unit 30. Is stopped (step S6).

<4. Modification>
As mentioned above, although main embodiment of this invention was described, this invention is not limited to said embodiment.

FIG. 12 is a longitudinal sectional view of a drying unit 30 according to a modification. In FIG. 12, the same reference numerals are given to the same parts as those in the above embodiment. In the example of FIG. 12, the plurality of outlets 31 of the drying unit 30 are arranged horizontally. And the some blower outlet 31 opposes the part to which the tablet 9 moves horizontally among the conveyance paths of the tablet 9. As shown in FIG. In the configuration of FIG. 12, the tablet transport mechanism 10 and the drying unit 30 are arranged so as to overlap each other. Therefore, although the vertical dimension of the tablet printing apparatus 1 is increased as compared with the above embodiment, the horizontal dimension can be suppressed.

On the other hand, in the configuration of the above embodiment, the tablet transport mechanism 10 and the drying unit 30 are arranged so as to overlap in the horizontal direction. Accordingly, although the horizontal dimension of the tablet printing apparatus 1 is increased as compared with the example of FIG. 12, the vertical dimension can be suppressed.

FIG. 13 is a longitudinal sectional view of a drying unit 30 according to another modification. In FIG. 13, parts that are the same as in the above embodiment are given the same reference numerals. In the example of FIG. 13, the exterior cover 70 is provided with an exhaust part 74 and an outside air introduction part 75. The exhaust unit 74 is provided with an exhaust fan 741. The outside air introduction unit 75 is provided with an outside air introduction fan 751. When the exhaust fan 741 and the outside air introduction fan 751 are operated, a part of the gas in the circulation duct 32 is discharged to the outside through the exhaust part 74 and the outside gas passes through the outside air introduction part 75. It is taken into the circulation duct 32.

In this way, the humidity of the gas circulating in the drying unit 30 can be lowered. Therefore, it is possible to prevent the humidity of the gas from becoming excessively high due to water evaporated from the ink. Thereby, the drying performance of the drying unit 30 can be improved.

Further, in the above-described embodiment, the suction ports 73 that are a plurality of small circular holes are vertically arranged between the rows of the outer blowout ports 72 adjacent in the width direction of the exterior cover 70. And the outer blower outlet 72 and the suction opening 73 were substantially the same magnitude | size. However, the outer outlet 72 may have a size different from that of the suction port 73. Further, a slit-like suction port 73 extending vertically may be provided between the rows of the outer blowout ports 72 adjacent in the width direction.

Further, the blower fan 81 and the heater 82 may each be capable of adjusting the output. In addition, the control unit 40 adjusts the output of one or both of the blower fan 81 and the heater 82 in accordance with various conditions such as the type of the tablet 9, the ink discharge amount in the printing unit 20, and the conveyance speed of the tablet 9. May be.

In the above embodiment, the tablets 9 are conveyed while adsorbing and holding the tablets 9 in the adsorption holes 14 of the conveyance belt 12. However, other methods may be used for holding and transporting the tablets 9.

In the above embodiment, the printing unit 20 is provided with 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.

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

Further, the detailed configuration of the tablet printing apparatus 1 may be different from the drawings of the present application. Moreover, you may combine suitably each element which appeared in said embodiment and modification in the range which does not produce inconsistency.

DESCRIPTION OF SYMBOLS 1 Tablet printer 9 Tablet 10 Tablet conveyance mechanism 11 Pulley 12 Conveyance belt 13 Conveyance motor 14 Adsorption hole 15 Suction mechanism 16 Blow mechanism 20 Printing part 21 Head 30 Drying unit 31 Outlet 32 Circulation duct 40 Control part 51 Loading mechanism 52 Unloading Mechanism 60 Supply duct 61 Vertical pipe part 62 Horizontal pipe part 63 Hot air nozzle part 64 Branch nozzle 65 Blowing surface 66 Inner outlet 70 Exterior cover 71 Ventilation surface 72 Outer outlet 73 Suction port 74 Exhaust part 75 Outside air introduction part 81 Blower fan 82 Heater 83 Filter 84 Split plate 85 Current plate

Claims (18)

A drying unit that dries ink attached to the surfaces of a plurality of tablets to be conveyed,
A blower fan that forms a flow of gas;
A heater for heating the gas;
A plurality of outlets for blowing the heated gas toward the tablets;
Have
Each of the plurality of air outlets is a drying unit provided at a position facing the tablets to be conveyed. The drying unit according to claim 1,
The plurality of tablets are transported in a state aligned in the width direction orthogonal to the transport direction,
Each of the plurality of air outlets is a drying unit provided at a position in the width direction corresponding to a tablet. A drying unit according to claim 2,
Each of the plurality of air outlets is a drying unit that blows out gas in a direction perpendicular to the transport direction and the width direction. A drying unit according to claim 3,
A drying unit further comprising a rectifying plate provided at each of the plurality of air outlets. A drying unit according to any one of claims 2 to 4,
A plurality of suction ports for sucking the gas blown from the blowout port;
A circulation duct for sending gas from the plurality of suction ports to the blower fan;
Further comprising a drying unit. A drying unit according to claim 5,
The drying unit in which the air outlets and the suction ports are alternately arranged in the width direction. The drying unit according to claim 5 or 6,
A supply duct for sending gas from the blower fan to the plurality of outlets;
An exterior cover covering the supply duct;
Have
A drying unit in which the circulation duct is formed between the supply duct and the exterior cover. A drying unit according to claim 7,
The exterior cover is
An exhaust section for discharging gas to the outside;
An outside air introduction section for taking in gas from the outside;
Having a drying unit. A drying unit according to any one of claims 1 to 8,
A drying unit in which a hot air nozzle portion having the plurality of outlets is detachable. A drying unit according to any one of claims 1 to 9,
A drying unit further comprising a flow dividing plate that divides the heater and the plurality of outlets into a plurality of flow paths. A drying unit according to any one of claims 1 to 10,
A drying unit further comprising a filter for removing dust from the gas toward the air outlet. A drying unit according to any one of claims 1 to 11,
The blower fan is a drying unit arranged at a position lower than the heater. A drying unit according to any one of claims 1 to 12,
The blower fan is a drying unit that is a counter-rotating fan. A drying unit according to any one of claims 1 to 13,
The blower fan and the heater are each a drying unit whose output can be adjusted. A tablet printing apparatus for printing on the surface of a tablet,
A transport mechanism for transporting a plurality of tablets;
A head for ejecting ink droplets onto the surface of the tablet conveyed by the conveyance mechanism;
A drying unit according to any one of claims 1 to 14,
A tablet printing apparatus. A tablet printing apparatus for printing on the surface of a tablet,
A transport mechanism for transporting a plurality of tablets;
A head for ejecting ink droplets onto the surface of the tablet conveyed by the conveyance mechanism;
A drying unit according to any one of claims 5 to 8,
A controller for controlling the transport mechanism, the head, and the drying unit;
With
The transport mechanism is
An annular conveyor belt having a plurality of suction holes;
A mechanism for rotating the conveyor belt;
A suction mechanism for sucking out gas from the space inside the conveyor belt;
Have
The said control part is a tablet printing apparatus which starts the said ventilation fan and the said heater in the state which stopped the said suction mechanism at the time of starting of the said drying unit. A tablet printing apparatus for printing on the surface of a tablet,
A transport mechanism for transporting a plurality of tablets;
A head for ejecting ink droplets onto the surface of the tablet conveyed by the conveyance mechanism;
A drying unit according to any one of claims 5 to 8,
A controller for controlling the transport mechanism, the head, and the drying unit;
With
The transport mechanism is
An annular conveyor belt having a plurality of suction holes;
A mechanism for rotating the conveyor belt;
A suction mechanism for sucking out gas from the space inside the conveyor belt;
Have
The said control part is a tablet printing apparatus which stops the said heater in the state which operated the said suction mechanism, when the said drying unit stops. A drying method for drying ink adhering to the surface of a plurality of tablets to be conveyed,
a) heating the gas;
b) a step of blowing the heated gas toward the tablet;
Including
In the step b), a drying method in which gas is blown toward a tablet from a plurality of outlets provided at positions facing the transported tablet.

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