WO2016194761A1

WO2016194761A1 - Tablet printing device and tablet printing method

Info

Publication number: WO2016194761A1
Application number: PCT/JP2016/065561
Authority: WO
Inventors: 梓平野; 鶴岡　保次
Original assignee: 芝浦メカトロニクス株式会社
Priority date: 2015-05-29
Filing date: 2016-05-26
Publication date: 2016-12-08
Also published as: JPWO2016194761A1

Abstract

[Problem] To provide a tablet printing device which allows tablets printed by an ink-jet printing mechanism to be effectively dried without imposing a great heat load on a conveyor belt that conveys the tablets. [Solution] A tablet printing device includes: a conveyance mechanism 17 which causes a conveyor belt 171 to move in order to convey tablets that are sequentially dispensed; a printing mechanism which has an ink-jet head 21 provided with multiple nozzles that eject ink drops, the ink-jet head 21 being disposed facing a surface of the conveyor belt 171 to perform printing on the tablets at a printing position on the conveyor belt 171 by ejecting the ink drops from the multiple nozzles; and a drying mechanism 22 which outputs energy toward the tablets conveyed by the conveyor belt 171 at a drying position downstream of the tablets at the printing position in the conveyance direction.

Description

Tablet printing apparatus and tablet printing method

The present invention relates to a tablet printing apparatus and a tablet printing method for printing characters, marks, patterns and the like on the surface of a tablet.

Conventionally, a solid preparation printing apparatus (tablet printing apparatus) described in Patent Document 1 is known. In this solid preparation printing apparatus, a printing mechanism that performs printing (transfer) by a transfer roller on the surface of a solid preparation (tablet) sequentially conveyed by a conveyor (conveyance belt) prints characters, marks, and the like. In the conveyor, pockets having micro holes formed in the transport direction are arranged, and the solid preparation is sequentially transported by moving the conveyor while the solid preparation is accommodated in the pocket. An air suction part that sucks air through the micro holes of each pocket is provided on the back side of the part of the conveyor facing the transfer roller, and faces the transfer roller of the conveyor by the air suction action by the air suction part. The solid preparation contained in each pocket of the part is securely fixed in the pocket. Thereby, it can transfer (print) reliably, without shifting a character, a mark, etc. to the solid formulation accommodated in each pocket by the transfer roller. Further, a hot air dryer is provided on the downstream side in the transport direction of the solid preparation of the printing mechanism to blow warm air on the surface of the conveyor and dry the ink transferred to the surface of each solid preparation that moves there. Yes.

JP-A-6-143539

By the way, in the tablet printing apparatus which prints on tablets such as solid preparations as in the conventional solid preparation printing apparatus described above, a plurality of nozzles for ejecting ink droplets are used instead of the printing mechanism using the transfer roller. It is conceivable to use an inkjet printing mechanism (so-called inkjet printer) that has an inkjet head provided and performs printing by ejecting ink droplets from a plurality of nozzles of the inkjet head according to a pattern based on print data. When such an ink jet printing mechanism is used, there is an advantage that even if characters or marks to be printed are changed by changing the type of tablet or the like, it is possible to respond immediately by changing the print data to be provided. In addition, when a tablet that is a printing object is to be drunk, it is hygienic because printing can be performed in a non-contact manner by using an ink jet printing mechanism.

Thus, in a tablet printing apparatus that uses an inkjet printing mechanism for tablet printing, ink with a relatively low viscosity is used from the viewpoint of preventing ink clogging of each nozzle in the printing mechanism. Since such an ink has a high solvent ratio and a high boiling point, it takes a long time to slow down the conveyance speed (printing speed) in order to properly dry the ink of the printed tablet, or In order to maintain a high conveyance speed (printing speed), high heat energy must be applied. In particular, when printing on sugar-coated tablets, the ink on the surface is empirically difficult to dry, and this tendency is remarkable.

However, when such high heat energy, for example, high-temperature hot air is constantly applied toward the surface of the conveyance belt that conveys the tablets as in the conventional solid preparation printing apparatus, the thermal degradation of the conveyance belt. (Thermal fatigue) progresses quickly.

The present invention has been made in view of such circumstances, and can effectively dry tablets printed by an ink jet printing mechanism without imposing a large heat burden on a conveying belt that conveys the tablets. A tablet printing apparatus is provided.

The tablet printing apparatus according to the present invention includes an ink jet head having a transport mechanism that moves a transport belt to transport tablets that are sequentially supplied, and a plurality of nozzles that eject ink droplets. A printing mechanism that is arranged to face the surface of the conveyor belt and performs printing by ejecting ink droplets from a plurality of nozzles to the tablet at the printing position on the conveyor belt, and the conveyance direction of the tablet at the printing position A drying mechanism that outputs energy toward the tablets transported by the transport belt at a downstream drying position, and the drying mechanism is when the tablet passes through the drying position. Energy output to the tablet when the tablet does not pass through the dry position and when the tablet passes through the dry position. A configuration for outputting a smaller energy than over.

According to the present invention, a tablet printed by an inkjet printing mechanism can be effectively dried without imposing a large heat load on a transport belt that transports the tablet.

It is a figure which shows typically the whole structure of the tablet printing apparatus which concerns on embodiment of this invention. It is a side view which expands and shows the laser beam irradiated from the laser unit as a drying mechanism. The side view which expands and shows the laser beam irradiated from the laser unit of the state approached to the tablet from the state shown to FIG. 2A. The side view which expands and shows the laser unit irradiated from the laser unit in the state away from the tablet from the state shown in FIG. 2A. It is a top view which shows an example of the relationship between the spot on the tablet of the laser beam irradiated from a laser unit, and a tablet. It is a block diagram which shows the basic composition of the control system which controls the laser unit as a drying mechanism. It is an example of the timing chart showing output control of the 1st laser unit. It is another example of the timing chart showing output control of the 1st laser unit. It is a side view which shows the other state of the laser beam irradiated from a laser unit (drying mechanism). It is a side view which expands and shows the other structural example of a drying mechanism. It is a figure which shows the other example of the drying mechanism arrange | positioned around a conveyance belt. It is a side view which expands and shows other structural examples of a drying mechanism. It is a figure which shows the 1st operation position of a shutter mechanism. It is a figure which shows the 2nd operation position of a shutter mechanism. It is a figure which shows the 1st operation position of another shutter mechanism. It is a figure which shows the 2nd operation position of another shutter mechanism. It is a figure which shows the tablet printing apparatus which concerns on other embodiment of this invention. It is a front view which shows a preheating laser unit. It is a side view which shows a preheating laser unit. It is a figure which shows typically the whole structure of the tablet printing apparatus provided with the cover which covers each mechanism.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Tablets Tb which are printing objects of the tablet printing apparatus according to the present invention include uncoated tablets (plain tablets), sugar-coated tablets, film-coated tablets (FC tablets), enteric tablets, gelatin-encapsulated tablets, multilayer tablets, dry tablets, etc. In addition to tablets and tablets of the above, capsule tablets such as hard capsules and soft capsules and other small solids similar to these can be used, regardless of their use, such as pharmaceuticals, foods, detergents, and industrial use. However, the tablet to be printed needs to be resistant to the thermal energy given by the drying mechanism as will be described later.

The tablet printing apparatus according to an embodiment of the present invention is configured as shown in FIG. In FIG. 1, a first vibration feeder 12a and a second vibration feeder 12b are continued from a hopper 11 for storing tablets to be printed, and a first delivery feeder 13 and an alignment feeder 14 are further arranged from the second vibration feeder 12b. . A first transport mechanism 17 is disposed behind the alignment feeder 14, and a second delivery feeder 16 is disposed so as to cover the rear end portion of the alignment feeder 14 and the front end portion of the first transport mechanism 17 from above. Yes.

Each of the first vibration feeder 12a and the second vibration feeder 12b has, for example, a structure in which a vibrator is provided in a bowl-shaped conveyance path, and the tablets Tb sequentially supplied from the hopper 11 are conveyed by vibration. It moves sequentially in the road toward the alignment feeder 14. The alignment feeder 14 has a structure in which alignment guides are arranged on the conveyance path, and the tablets Tb are divided into, for example, two rows by the alignment guide, and the tablets Tb in each row are directed toward the second delivery feeder 16. Convey sequentially. Each of the first delivery feeder 13 and the second delivery feeder 16 has a structure in which a conveyance belt having gas permeability is wound around two pulleys, and an intake chamber coupled to an intake device is provided inside the conveyance belt. It has become. And in the 1st delivery feeder 13, a conveyance belt receives and conveys the tablet Tb from the 1st vibration feeder 12b by the intake action of an intake chamber, and delivers it to the alignment feeder 14 in the position where the intake action of the said intake chamber stops working. . Further, in the second delivery feeder 16, the transport belt receives and transports the tablets Tb from the alignment feeder 14 by the intake action of the intake chamber, and delivers the tablets Tb to the first transport mechanism 17 at a position where the intake action of the intake chamber does not work. .

The first transport mechanism 17 has a structure in which a transport belt 171 having gas permeability is wound around two pulleys. One pulley is a drive pulley driven by the motor M, and the other pulley is a driven pulley. The annular conveying belt 171 is rotated by the rotation of the driving pulley accompanying the driving of the motor M. An encoder 45 (referred to as a first encoder) 45 that operates with the rotation of the drive shaft of the motor M is provided. An intake device (for example, a vacuum pump) (not shown) and an intake chamber coupled to the intake device are provided inside the annular conveyance belt 171. Due to the intake action of the intake chamber, air is sucked from the back side of the conveyance belt 171 having gas permeability, whereby the tablets Tb are adsorbed and held on the surface of the conveyance belt 171.

This tablet printing apparatus has an inkjet head with a plurality of nozzles that eject ink droplets, and ejects ink droplets from each nozzle by driving energy generating elements such as piezoelectric elements and thermal elements in accordance with print data. Ink jet printing mechanisms (so-called ink jet printers) that perform printing are used. Around the transport belt 171, an inkjet head (referred to as a first inkjet head) 21 of the printing mechanism, a laser unit (referred to as a first laser unit) 22 as a drying mechanism for drying the ink of the printed tablet Tb, for example, A first tablet sensor 23 constituted by a reflection type optical sensor, a first posture confirmation camera 24 and a first print confirmation camera 25 constituted by an imaging device having a CCD and the like, and two

collection trays

28a and 28b. Is provided. Two

air jet nozzles

26 a and 26 b are provided inside the transport belt 171 so as to face the

collection trays

28 a and 28 b with the transport belt 171 interposed therebetween.

As described above, the tablets Tb arranged in two rows by the alignment feeder 14 are supplied to the transport belt 171 of the first transport mechanism 17 through the second delivery feeder 16. In this case, in order to perform printing on each of the two rows of tablets Tb on the transport belt 171, actually, the first inkjet head 21, the first laser unit 22, the first tablet sensor 23, the first posture described above are used. Two sets of the confirmation camera 24, the first print confirmation camera 25, the two

air injection nozzles

26a and 26b, and the two

collection trays

28a and 28b are provided so as to correspond to the two rows of tablets Tb. Since these two sets perform the same operation, only one set will be described below.

The first inkjet head 21, the first laser unit 22, the first tablet sensor 23, the first posture confirmation camera 24, the first print confirmation camera 25, the two

air injection nozzles

26a and 26b, and the two collections described above. All or a part of the

trays

28a and 28b can be used for printing tablets for two rows in one set.

The first inkjet head 21 (a plurality of nozzles) is disposed to face the surface of the conveyor belt 171 at the printing position Pp. The first tablet sensor 23 is disposed so as to correspond to the tablet detection position Pd set at a predetermined position on the upstream side in the moving direction D (the transport direction D of the tablet Tb) of the transport belt 171 at the printing position Pp. And the 1st tablet sensor 23 outputs the detection signal based on the presence or absence of the tablet Tb on the conveyance belt 171 in the tablet detection position Pd. The imaging region of the first posture confirmation camera 24 includes a predetermined range between the printing position Pp of the conveyance belt 171 and the tablet detection position Pd. The first laser unit 22 is arranged so that its optical axis corresponds to the drying position Pdr. The drying position Pdr is set to a predetermined position on the downstream side in the moving direction D of the conveying belt 171 at the printing position Pp (the conveying direction D of the tablet Tb). The imaging region of the first print confirmation camera 25 is set to a predetermined range on the downstream side of the drying position Pdr in the moving direction D of the transport belt 171 (the transport direction D of the tablets Tb). The two

air injection nozzles

26 a and 26 b and the two

storage trays

28 a and 28 b are arranged so as to sandwich the lower part folded back by the drive pulley of the transport belt 171.

The second transport mechanism 18 has a structure substantially similar to the structure of the first transport mechanism 17 described above. Specifically, the second transport mechanism 18 has a structure in which a transport belt 181 having gas permeability is wound around a driving pulley driven by a motor M and a driven pulley, and is disposed inside the transport belt 181. An air intake device (not shown) and an air intake chamber coupled to the air intake device are provided, and the tablet Tb is adsorbed and held on a surface in a predetermined range excluding a portion of the conveyor belt 181 wound around the driven pulley. Around the transport belt 181, a second inkjet head 31 (printing position Pp) of the inkjet printing mechanism, a second laser unit 32 (drying position Pdr) as a drying mechanism, and a second tablet sensor 33 (detection position Pd). ), A second posture confirmation camera 34, a second print confirmation camera 35, and two

collection trays

38a and 38b. In addition, two

air injection nozzles

36 a and 36 b are disposed inside the transport belt 181 so as to face the two

collection trays

38 a and 38 b with the transport belt 181 interposed therebetween. In particular, in the second transport mechanism 18, the storage tray 40 is disposed to face the most downstream portion in the moving direction D of the transport belt 181 (the transport direction D of the tablets Tb).

As shown in FIG. 2A, the first laser unit 22 (second laser unit 32) provided as a drying mechanism in the first transport mechanism 17 (second transport mechanism 18) has the optical axis OA at the drying position Pdr. When the printed tablet Tb that is arranged correspondingly and is transported by the transport belt 171 (181) passes through the drying position Pdr, the tablet Tb irradiates (outputs) the laser beam LL and passes through the drying position Pdr. Give energy individually. In other words, the first laser unit 22 (second laser unit 32) is an energy supply unit and outputs energy. This energy is absorbed by the tablet or ink and becomes thermal energy. The first laser unit 22 (second laser unit 32) irradiates the laser beam LL via the optical unit 221 (321). This optical unit 221 (321) is comprised by optical components, such as a condensing lens, a reflective mirror, and an optical fiber, for example. The spot of the laser beam LL on the surface of the tablet Tb is set to a size that substantially covers the tablet Tb. That is, the irradiation range of the laser beam LL, in other words, the irradiation range of energy is set to a size that substantially covers the tablet Tb, and is applied to the transport belt 171 so as to irradiate only the tablet Tb as much as possible. The range is set to be as small as possible. In addition, as shown in FIG. 3, when printing PP such as characters and marks on an elongated tablet Tb, the spot SP _LL of the laser beam LL covers, for example, the entire elongated tablet Tb. It is set to a circle whose diameter is the major axis of the tablet Tb.

In the tablet printing apparatus having the above-described structure, characters and marks are sequentially printed on the surface of the tablet Tb as described below under the control of the print control unit 100.

As described above, the tablets Tb sequentially supplied from the hopper 11 and moving through the first vibration feeder 12a and the second vibration feeder 12b are delivered to the alignment feeder 14 by the first delivery feeder 13. Then, for example, the tablets Tb arranged in two rows are sequentially delivered to the first transport mechanism 17 by the second delivery feeder 16 by the alignment feeder 14. The tablets Tb sequentially delivered to the first transport mechanism 17 by the alignment feeder 14 are sequentially transported in two rows while being attracted and held on the transport belt 171 (transport step).

When the tablet Tb (located at the tablet detection position Pd) is detected based on the detection signal from the first tablet sensor 23 in the process of transporting the tablets Tb in each row, the value of the first encoder 45 is thereafter used. The detected position of the tablet Tb based on the tablet detection position Pd is recognized by the print control unit 100 (tracking step). Then, when the tablet Tb enters the imaging region of the first posture confirmation camera 24, it is determined whether or not the tablet Tb is damaged, such as dirt or chips, based on the photographed image by the first posture confirmation camera 24. The posture of the tablet Tb determined to be absent on the surface of the transport belt 171 (including the posture such as the front and back of the tablet Tb, the position on the belt, the holding direction on the belt, and the inclination in the vertical direction) ) Is determined. After that, when the tablet Tb determined not to be damaged passes through the printing position Pp, the first inkjet is performed according to the print data generated based on the information (determination result) on the detected damage and posture of the tablet Tb. The ejection pattern of the ink droplets from the plurality of nozzles of the head 21 is controlled, and characters, marks, and the like are printed in a normal direction at a normal position on the surface of the tablet Tb (printing step). At this time, the tablet Tb determined to be damaged is not printed. That is, print data not to be printed is generated. Thereafter, the print control unit 100 tracks the position of the tablet Tb that has not been printed (based on the value of the encoder 45).

When the printed tablet Tb passes through the printing position Pp and further passes through the downstream drying position Pdr, the first laser unit 22 performs laser control under the control of the drying control unit 200 described later in detail. Irradiation with light LL gives thermal energy individually to the tablets Tb passing through the drying position Pdr (drying step: see FIGS. 2A and 3). Thereby, the ink of the printed tablet Tb is dried. When the tablet Tb that has undergone printing (printing position Pp) and drying (drying position Pdr) enters the imaging region of the first printing confirmation camera 25, characters are normally printed on the tablet Tb based on the image captured by the first printing confirmation camera 25. Whether or not a mark has been printed is determined. Thereafter, the print control unit 100 tracks the position of the tablet Tb (based on the value of the first encoder 45) determined to have not been printed normally.

The tablet Tb that has completed printing and drying and has passed the imaging region of the first print confirmation camera 25 is transported as the transport belt 171 moves. Then, when the tablet Tb whose position is tracked by the printing control unit 100 without being printed due to damage such as a chip reaches a position facing one of the air injection nozzles 26a, the tablet Tb is injected from the air injection nozzle 26a. The air is blown from the conveyor belt 171 by the air to be collected and collected in the collection tray 28a. Further, although there is no damage such as chipping, when the tablet Tb whose position is being tracked by the printing control unit 100 without being printed normally reaches the position facing the other air injection nozzle 26b, the air injection is performed. The air is ejected from the conveying belt 171 by the air ejected from the nozzle 26b and is collected on the other collection tray 28b.

The tablet Tb on which characters and marks are normally printed on the surface is transported with the movement of the transport belt 171 and is separated from the transport belt 171 at a position where the suction action of the suction chamber stops working. It moves on the conveyor belt 181. In this way, the tablet Tb that has been normally printed on the surface is delivered from the first transport mechanism 17 to the second transport mechanism 18. That is, it is delivered in a state where the printed surface is turned upside down so as to be on the conveying belt 181 side.

Also in the second transport mechanism 18, as in the case of the first transport mechanism 17, the output timing of the detection signal of the second tablet sensor 33 (tablet detection position Pd) is set as a base point under the control of the print control unit 100. Based on the value of the second encoder 46, the position of the tablets Tb sequentially conveyed with the movement of the conveying belt 181 is tracked, and the characters by the second inkjet head 31 (located at the printing position Pp) with respect to the back surface of each tablet Tb Printing of marks, marks, etc., individual drying of printed tablets Tb by the laser light LL emitted from the second laser unit 32, recovery of damaged tablets Tb to the recovery tray 38a by the air injection nozzle 36a, and air injection The poorly printed tablets Tb are collected to the collection tray 38b by the nozzles 36b. The normally printed tablet Tb falls and is stored in the storage tray 40 at a position where the suction action of the suction chamber stops working.

In this tablet printing apparatus, as a control system, in addition to the above-described printing control unit 100, the drying control unit 200 that controls the emission timing of the laser light LL of the first laser unit 22 and the second laser unit 32 as a drying mechanism. have. The print control unit 100 controls the drying control unit 200 and other controls, for example, control of each unit such as the vibration feeders 12a and 12b, the alignment feeder 14, and the

delivery feeders

13 and 16, and data necessary for the operation of each unit. It also performs overall control of the tablet printing device, including input / output, storage, etc. As shown in FIG. 4, the drying control unit 200 inputs a detection signal from the first tablet sensor 23 and an output signal representing a value from the first encoder 45, and based on these signals, the first transport mechanism 17. The position of the tablet Tb conveyed along with the movement of the conveying belt 171 is tracked at a position based on the tablet detection position Pd (tracking step), and at the timing when each tablet Tb passes the drying position Pdr, the first laser unit 22 is controlled (drying step). Similarly, the drying control unit 200 inputs a detection signal from the second tablet sensor 33 and an output signal representing a value from the second encoder 46, and the conveyance of the second conveyance mechanism 18 based on these signals. The positions of the tablets Tb conveyed along with the movement of the belt 181 are tracked based on the tablet detection position Pd, and the light emission control of the second laser unit 32 is performed at the timing when each tablet Tb passes the drying position Pdr. Perform (drying step).

For example, the drying control unit 200 causes the first laser unit 22 to emit light during a period (period Ton) in which it is determined that the tablet Tb has passed the drying position Pdr based on the value from the first encoder 45. After the tablet Tb passes the drying position Pdr, the first laser unit is a period until it is determined that the next tablet Tb has reached the drying position Pdr, that is, the period when the tablet Tb does not exist at the drying position Pdr (period Toff). 22 does not emit light (drying step). Therefore, as shown in FIG. 5A, the light emission and non-light emission of the first laser unit 22 are repeated each time each printed tablet Tb passes through the drying position Pd. That is, under the control of the drying control unit 200, during the period Ton during which the first laser unit 22 emits light, as shown in FIG. 2A, the first laser unit 22 that has passed the drying position Pdr has been printed. Laser energy LL is individually applied by irradiating the laser beam LL toward the tablet Tb. That is, energy is output toward the tablet Tb. As a result, the ink of the printed tablet Tb that passes through the drying position Pdr is dried.

The second laser unit 32 is similarly controlled to emit light, and when the printed tablet Tb passes through the drying position Pdr in the second transport mechanism 18, the second laser unit 32 emits the laser beam LL. Is applied to each of the printed tablets Tb to individually apply heat energy, whereby the ink of the printed tablets Tb is dried.

The output intensity of the laser beam LL from the first laser unit 22 and the second laser unit 32 is an absorption characteristic depending on the wavelength of the laser beam LL of the ink used, and each tablet by the

transport belts

171 and 181. It can be determined based on the transport speed of Tb, the distance between the first laser unit 22 and the second laser unit 32 and the surface of the tablet Tb at the drying position Pdr.

According to the tablet printing apparatus as described above, it is sufficient that the ink of the printed tablet Tb can be dried, and instead of always irradiating heat energy toward the

conveyor belts

171 and 181, the ink is conveyed by the

conveyor belts

171 and 181. When the printed tablet Tb to be printed passes through the drying position Pdr, the laser of a spot set to a size that substantially covers the tablet Tb irradiated from the first laser unit 22 and the second laser unit 32 Since the heat LL necessary for drying the ink is individually given to the tablets Tb passing through the drying position Pdr by the light LL, assuming that the ink of the printed tablets Tb can be dried, it is always directed toward the

transport belts

171 and 181. Compared to the irradiation of thermal energy, the range of thermal energy given to the

conveyor belts

171 and 181 is better. Small and can be made shorter time. As a result, it is possible to reduce the effect of heat on the

conveyor belt

171 and 181. Therefore, the tablet Tb printed by the inkjet printing mechanism can be effectively dried without imposing a large heat load on the

transport belts

171 and 181 that transport the tablet Tb.

In the example described above, as shown in FIG. 5A, the drying control unit 200 emits light when the printed tablet Tb passes through the drying position Pd, and does not emit light during the period when the tablet Tb does not pass. Although one laser unit 22 (second laser unit 32) is controlled, the present invention is not limited to this. As shown in FIG. 5B, the drying control unit 200 determines that the period when the tablet Tb passes the drying position Pdr based on the value from the first encoder 45 (second encoder 46) (period TH). A period (period TL) until it is determined that the next tablet Tb has reached the dry position Pdr after the first laser unit 22 emits light (for example, output 100%) and the tablet Tb passes the dry position Pdr. ) Does not completely turn off the first laser unit 22 (second laser unit 32), but a small amount of output that does not adversely affect the conveyor belt 171 (181), for example, 10% output. Thus, the output of the first laser unit 22 (second laser unit 32) can be controlled (drying step). In this case, from the state where the first laser unit 22 (second laser unit 32) outputs a small amount of output (for example, 10%) in advance, the output (for example, 100) becomes the heat energy necessary for drying the ink. %), The rise time can be shortened. Thereby, even when the tablets Tb are transported at a higher speed, each tablet Tb can be irradiated with laser light accurately, and an appropriate amount of heat energy can be individually applied to the tablets Tb.

In the above-described example, the spot diameter (irradiation range) of the laser beam LL emitted from the first laser unit 22 (second laser unit 32) is the effective value of the condenser lens (optical unit 221 (321)). Although it is set by the diameter and the focal distance, for example, irradiation may be performed while shifting the focal position. When the condenser lens is used, the distance between the condenser lens (optical unit 221 (321)) and the tablet Tb is adjusted, that is, the focal position is adjusted, as shown in FIGS. 2B and 2C. A necessary irradiation range can be set for the tablets Tb having different sizes. For example, as shown in FIG. 2B, the spot diameter of the laser beam LL on the surface of the conveyor belt 171 is increased by bringing the first laser unit 22 closer to the conveyor belt 171 so that the focal point is located farther from the tablet Tb. Can be adjusted to a large tablet Tb. Further, as shown in FIG. 2C, the spot diameter of the laser beam LL on the surface of the conveyor belt 171 can be reduced by moving the first laser unit 22 away from the conveyor belt 171 so that the focal point is located near the tablet Tb. , It can be adjusted to a small tablet Tb.

Moreover, even if a focal point is provided between the tablet Tb and a condenser lens (optical unit 221 (321)) (not shown) as shown in FIG. be able to. Since only the distance between the tablet Tb and the condensing lens is changed as described above, the irradiation range of the laser beam LL can be easily changed even if the size of the tablet Tb is changed. When the focal position is shifted, for example, as shown in FIG. 6, the focal point FP of the laser beam LL emitted from the first laser unit 22 (second laser unit 32) is changed to the first laser unit 22. When the position is between the (second laser unit 32) and the surface of the tablet Tb, the laser beam LL emitted from the first laser unit 22 (second laser unit 32) is collected at the focal point FP. The light is diffused, and the diffused laser beam LL is irradiated onto the tablet Tb.

Since the laser beam LL deviating from the focal point is irradiated onto the surface of the tablet Tb, the thermal energy density of the irradiation range Ebt of the laser beam LL on the surface of the transport belt 171 (181) is the surface of the tablet Tb. It becomes smaller than the thermal energy density of the irradiation range Etb of the laser beam LL. For this reason, even if it is a tablet which is not circular like FIG. 3 and includes irradiation ranges other than a tablet, the thermal burden by the laser beam on the surface of the conveyance belt 171 (181) to a conveyance belt can be made small. it can.

Further, in the above-described example, the thermal energy is given to the tablet Tb by the laser beam LL from the single laser unit 22 (32) (see FIGS. 2A to 2C), but is not limited to this. For example, as shown in FIG. 7A, a plurality of, for example, two

laser units

22a and 22b (energy supply units) are irradiated with laser beams LL1 and LL2 obliquely from the oblique direction with respect to the tablet Tb. It is also possible to give thermal energy to Tb individually. In this case, the intensity of the laser beams LL1 and LL2 emitted from the

respective laser units

22a and 22b is the total intensity of the two laser beams LL1 and LL2 that is necessary for drying the ink on the surface of the tablet Tb. To be adjusted.

When a plurality of (two)

laser units

22a and 22b are used in this way, the intensity of the laser beams LL1 and LL2 from the

laser units

22a and 22b can be kept low, and the laser beams LL1 and LL1 from an oblique direction can be suppressed. By diffusing LL2 by irradiating the tablet Tb, the thermal energy density by the laser beams LL1 and LL2 on the

conveyor belts

171 and 181 can be kept low. For this reason, the heat burden by the laser beam on the surface of the conveyance belt 171 (181) can be further reduced.

As each of the

laser units

22a and 22b shown in FIG. 7A, it is possible to use a laser unit in which the focal points of the laser beams LL1 and LL2 are formed in front of the tablet Tb as shown in FIG. . In this case, the thermal energy density on the

conveyor belts

171 and 181 irradiated with the laser beams LL1 and LL2 can be further reduced.

Further, as shown in FIG. 7B, a plurality of

laser units

22u and 22d (energy supply units) are arranged side by side at a plurality of drying positions Pdru and Pdrd set at predetermined intervals along the transport direction of the tablet Tb. A plurality of thermal energy may be given to one tablet Tb. It suffices that the sum of the thermal energy given to one tablet Tb a plurality of times is sufficient to dry the ink. Therefore, the heat energy per one time becomes small, and the heat burden on the surface of the conveyor belt 171 (181) can be reduced in the vicinity of the tablet Tb.

Further, as shown in FIG. 7C, a single laser unit 22 (32) may be used to divide the laser beam emitted by the optical unit 221 (321) into a plurality of laser beams LL1 and LL2. Each irradiation angle may be varied, or irradiation spots may be arranged in the transport direction of the tablet Tb.

In the tablet printing apparatus described above, energy is output by controlling the light emission of each of the

laser units

22 and 32, and thermal energy is individually applied to the printed tablets Tb, but is not limited thereto. For example, as shown in FIGS. 8A and 8B, the shutter plate 51 that blocks the laser light LL that is constantly emitted from the laser unit 22 (23) may be moved forward and backward by the forward / backward moving mechanism 50 (moving mechanism). Yes (shutter mechanism). In this case, the shutter plate 51 is moved to the retracted position by the advance / retreat mechanism 50 as shown in FIG. 8A during a period when it is determined that the printed tablet Tb has passed the drying position Pdr. During this period, the laser beam LL from the

laser units

22 and 23 is irradiated onto the printed tablet Tb. On the other hand, as shown in FIG. 8B, after the tablet Tb passes through the drying position Pdr and until it is determined that the next tablet Tb has reached the drying position, the forward / backward movement mechanism 50 causes the shutter plate 51 to move the laser beam LL. The laser beam LL from the

laser units

22 and 32 is blocked by moving inward. By repeating such an operation, the

laser units

22 and 23 irradiate the laser beam LL and individually give thermal energy to the printed tablets Tb passing through the drying position Pdr. Thereby, the ink of the printed tablet Tb passing through the drying position Pdr is dried while reducing the heat load on the transport belt.

In the shutter mechanism, instead of the shutter plate 51 (see FIGS. 8A and 8B), a shutter plate 52 having an opening 52a can be used as shown in FIGS. 9A and 9B. In this case, the

laser units

22 and 32 are irradiated with laser light LL having a relatively large irradiation range (energy is output). Then, during the period in which it is determined that the printed tablet Tb has passed the drying position Pdr, as shown in FIG. 9A, the shutter 52 is moved by the advancing / retreating mechanism 50 so that the opening 52a is located at the position matching the drying position Pdr. The plate 52 is moved. During this period, the laser light LL from the

laser units

22 and 23 is masked by the shutter plate 52 in a region other than the opening 52a, and the printed tablet Tb is irradiated with the laser light LL passing through the opening 52a. . On the other hand, as shown in FIG. 9B, after the tablet Tb passes through the drying position Pdr, it is determined that the next tablet Tb has reached the drying position Pdr. It is moved to a position where all of the light LL is blocked. By repeating such an operation, the

laser units

22 and 23 individually apply heat energy to the printed tablets Tb that pass through the drying position Pdr by irradiating the laser beam LL. Thereby, the ink of the printed tablet Tb passing through the drying position Pdr is dried while reducing the heat load on the transport belt.

A plurality of shutter plates 52 having openings 52a corresponding to the size of the tablets Tb are prepared in advance, and the shutter plates 52 having openings 52a corresponding to the sizes of the tablets Tb to be printed are selectively selected. Can be used. Alternatively, a plurality of openings may be formed on one shutter plate and used selectively. Further, by adopting a structure in which the size of the opening 52a is variable, the size of the opening 52a can be changed according to the size of the tablet Tb to be printed. When such a shutter plate 52 (mask) is used, it is not necessary to use an expensive condensing optical system. Further, such a shutter plate 52 (mask) is not necessarily moved, and may be used together with on / off of energy sources such as the

laser units

22 and 23. Except for a predetermined range corresponding to the opening 52a not masked by the shutter plate 52, energy is not applied to the

conveyor belts

171 and 181, so that the burden on the

conveyor belts

171 and 181 can be reduced.

Note that the movement of the shutter mechanism by the advance / retreat mechanism 50 may be performed so as to block or limit (mask) the irradiated energy, and may be linear movement or rotational movement. Further, the shutter plate of the shutter mechanism may be rectangular or disc-shaped. A known drive source such as a linear motor, a rotary motor, a voice coil, or an air cylinder can be used as the drive source for movement.

Further, when the

shutter plates

51 and 52 are formed of a material that absorbs the laser light LL, a cooling mechanism for cooling the

shutter plates

51 and 51 may be provided. Such a cooling mechanism can be configured, for example, by blowing cooling air, and can be applied to energy sources other than the laser beam LL. Further, the

shutter plates

51 and 52 may be formed of a material that does not absorb the energy of the laser beam LL or other energy sources. In this case, there is no need to provide a cooling mechanism. At this time, when the

shutter plates

51 and 52 reflect the energy of the laser beam LL and other energy sources, the energy of the reflected laser beam LL and other energy sources constitutes each unit constituting the tablet printing apparatus. It is also possible to form irregularities on the surfaces of the

shutter plates

51 and 52 so as to diffuse to the extent that they do not affect the light.

Also, as shown in FIG. 10, in the first transport mechanism 17 (similar in the second transport mechanism 18), toward the transport belt 171 on the downstream side in the transport direction D of the first laser unit 22 (drying mechanism). A blower unit 27 (gas supply mechanism: cooling mechanism) for blowing gas (for example, air) may be provided. In this case, the printed tablets Tb and the transport belt 171 heated by the heat energy given by the laser light LL emitted from the first laser unit 22 are cooled by the gas blown from the blower unit 27. Thus, by providing the blower unit 27 (gas supply mechanism: cooling mechanism), the thermal burden due to the laser light on the surface of the conveyor belt 171 can be further reduced. The blower unit 27 may be anywhere as long as it is downstream in the transport direction from the drying mechanism, but is preferably closer to the drying mechanism (first laser unit 22).

Moreover, as shown in FIG. 12, the tablet printing apparatus according to the embodiment of the present invention as shown in FIG. 1 includes the entire configuration included in the tablet printing apparatus such as the first transport mechanism 17 and the second transport mechanism 18. The cover 500 is provided with the

outside air inlets

510 and 520. The outside

air suction ports

510 and 520 are openings for introducing air outside the cover 500 into the cover 500. The opening is provided with a filter so that external dust or the like is not introduced into the cover 500.

As described above, the first transport mechanism 17, the second transport mechanism 18, and the like perform suction for adsorbing and holding the tablets Tb. That is, the surrounding air is inhaled. Therefore, when the tablet printing apparatus is covered with the cover 500, the air pressure in the cover 500 is reduced, so it is necessary to introduce air from the outside of the cover 500. For this reason, outside

air inlets

510 and 520 for introducing air from the outside of the cover 500 are provided. Thus, since the outside air from the outside of the cover 500 passes through the outside

air introduction ports

510 and 520, an air flow from the outside to the inside of the cover 500 is generated in the vicinity of the outside

air introduction ports

510 and 520. In FIG. 1, the drive pulley disposed on the right side of the first transport mechanism 17 and the drive pulley disposed on the left side of the second transport mechanism 18 are located near a cover 500 that covers the tablet printing apparatus. Therefore, if the

outside air inlets

510 and 520 are provided in the cover 500 near these drive pulleys, the airflow (see thick arrows) passing through the

outside air inlets

510 and 520 is caused to flow between the first transport mechanism 17 and the second transport mechanism 18. The surface of the

conveyor belts

171 and 181 can be reached. That is, the outside

air introduction ports

510 and 520 also function as a cooling mechanism. Therefore, in place of the blower unit 27 described above, the arrangement of the outside

air introduction ports

510 and 520 can also be used to blow the airflow generated at the outside

air introduction ports

510 and 520 onto the surfaces of the tablet Tb and the

conveyor belts

171 and 181. It is possible to further reduce the thermal burden due to the laser light on the surfaces of the

conveyor belts

171 and 181. In addition, you may provide the guide which guides an airflow from the external

air introduction ports

510 and 520 to the

conveyance belts

171 and 181 vicinity.

Also, it is possible to preheat the ink ejected from the respective nozzles of the first inkjet head 21 and the second inkjet head 31.

For example, as shown in FIGS. 11A and 11B, a preheating laser unit 60 (ink preheating mechanism) is provided for the first inkjet head 21. Specifically, the preheating laser unit 60 includes a laser light source 61, a light guide 62, and a light receiving portion 63. In addition, the preheating laser unit 60 can be similarly provided for the second inkjet head 31 (hereinafter, the preheating laser unit 60 for the first inkjet head 21 will be described).

The light guide 62 is disposed so as to extend in a direction (for example, a direction orthogonal) across the transport direction D of the tablet Tb. A light exit window 62 a is formed on the surface of the light guide 62 that faces the ink droplets ejected from each nozzle of the first inkjet head 21. A laser light source 61 is provided at one end of the light guide 62, and laser light output from the laser light source 61 is introduced into the light guide 62, and the laser light propagates through the light guide 62. Laser light is emitted from the light emission window 62a in the transport direction d of the tablet Tb. The laser light emitted from the light exit window 62 a of the light guide 62 is adjusted by the light guide 62 so as to be condensed in the vicinity of the flight path of the ink droplets ejected from each nozzle of the first inkjet head 21. The laser beam emitted from the light exit window 62 a of the light guide 62 is received by the light receiving portion 63.
Note that the emitted laser light does not necessarily have to be condensed and may be parallel light.

When such a preheating laser unit 60 is used, ink droplets ejected from the nozzles of the first inkjet head 21 are preheated before reaching the tablet Tb by the laser light emitted from the preheating laser unit 60. The thermal energy required for drying the ink of the tablet Tb can be reduced. As a result, the output intensity of the laser beam LL emitted from the first laser unit 22 as a drying mechanism can be reduced, and the thermal burden due to the laser beam on the surface of the conveyor belt 171 can be reduced.

Furthermore, the surface of the

transport belts

171 and 181 of the first transport mechanism 17 and the second transport mechanism 18 is made of a heat-dissipating paint (a material having a high radiation characteristic (emissivity) and a material having excellent radiation characteristics (emissivity) )) May be applied. In this case, it is possible to further reduce the heat burden due to the laser light on the surfaces of the

conveyor belts

171 and 181.

Note that the expression “thermal energy” described above includes energy that is absorbed by the object and changes from thermal energy, such as laser light, and includes electromagnetic waves such as ultraviolet rays, infrared rays, and microwaves. Therefore, a halogen lamp, an infrared lamp, a flash lamp, a magnetron, or the like can be applied as a means other than the laser unit that gives thermal energy for drying. Of course, a hot air blower or the like can also be applied. However, a laser unit is desirable from the standpoint of controllability and response of energy irradiation, and more particularly a semiconductor laser (LD).

The optical units of the first laser unit 22 and the second laser unit 23 are not limited to a condenser lens, a reflecting mirror, an optical fiber, or the like as long as the irradiation range of heat energy can be adjusted. The shutter may be a mechanism, or may be replaceable or selectable so that the irradiation range and focal length can be changed. A combination of these may also be used. The same applies to energy other than the laser light described above.

Furthermore, blowing a gas such as dry air that is not heated is also an output of energy, which gives energy for drying. Also in this case, the amount of gas flowing upstream or downstream in the transport direction of the tablet Tb at the dry position Pdr can be reduced by individually blowing gas to each tablet Tb with a spot set to a size that substantially covers the tablet Tb. Therefore, it is possible to reduce the influence of gas on the amount of air that sucks the tablet Tb, and the influence on the suction of the tablet Tb located there can be reduced. Thereby, it is possible to avoid problems such as a change in the tablet force due to fluctuations in the suction force and printing disturbance. Alternatively, a gas that reacts with the ink to remove the solvent and speeds drying may be used.

Also, the ink can be dried with less energy if a composition or additive that increases the absorption of various energy described above is used.

Also, if the composition, additive, surface treatment, surface coating, etc. that do not absorb or hardly absorb the various energy described above are used for the conveyor belt, the thermal burden on the conveyor belt can be further reduced.

In addition, although it has been described that energy is output toward the tablet Tb when the printed tablet Tb passes through the dry position Pdr, the tablet Tb that has not been printed due to damage or the like passes through the dry position Pdr. The energy may be output toward the tablet Tb even when the tablet is in operation. That is, regardless of whether or not printing is performed on the tablet Tb, the energy output toward the tablet Tb is blocked by the tablet Tb, so that the heat load on the transport belt can be reduced. Of course, when the tablet Tb that has not been printed passes through the dry position Pdr, the energy that is smaller than the energy that is output when the tablet Tb passes through the dry position Pdr is not output. Also good.

As mentioned above, although embodiment of this invention and the modification of each part were demonstrated, this embodiment and the modification of each part are shown as an example, and are not intending limiting the range of invention. These novel embodiments described above can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention and included in the invention described in the claims.

DESCRIPTION OF SYMBOLS 11 Hopper 12a 1st vibration feeder 12b 2nd vibration feeder 13 1st delivery feeder 14 Alignment feeder 16 2nd delivery feeder 17 1st conveyance mechanism 171 Conveyance belt 18 2nd conveyance mechanism 181 Conveyance belt 21 1st inkjet head 22 1st Laser unit (drying mechanism)
23 1st tablet sensor 24 1st attitude | position confirmation camera 25 1st

printing confirmation camera

26a, 26b Air injection nozzle 27 Blower unit (cooling mechanism)
28a, 28b Collection tray 31 Second inkjet head 32 Second laser unit (drying mechanism)
33 Second tablet sensor 34 Second posture confirmation camera 35 Second

printing confirmation camera

36a, 36b

Air injection nozzle

38a, 38b Collection tray 40 Storage tray 45 First encoder 46 Second encoder 50 Advance /

retreat mechanism

51, 52 Shutter plate (shutter) mechanism)
60 Preheating laser unit 61 Laser light source 62 Light guide 62a Light exit window 63 Light receiving unit 100 Print control unit 200 Drying control unit

Claims

A transport mechanism that moves the transport belt to transport the tablets that are sequentially supplied;
An inkjet head having a plurality of nozzles for ejecting ink droplets, the inkjet head being disposed opposite the surface of the transport belt, and a plurality of nozzles for a tablet at a printing position on the transport belt; A printing mechanism that performs printing by discharging ink droplets;
A drying mechanism that outputs energy toward the tablets transported by the transport belt at a drying position downstream of the printing position in the transport direction of the tablets;
The drying mechanism outputs energy toward the tablet when the tablet passes through the drying position, and when the tablet does not pass through the drying position, the tablet passes through the drying position. Tablet printing device that outputs less energy than the energy that is output.
The drying mechanism outputs energy toward the tablet when the tablet passes through the drying position, and does not output energy when the tablet does not pass through the drying position. Item 2. A tablet printing apparatus according to Item 1.
The drying mechanism has a plurality of energy supply units,
2. The tablet printing apparatus according to claim 1, wherein a total of thermal energy given to one tablet by each of the plurality of energy supply units is set as thermal energy necessary for drying ink on a surface of the tablet.
The tablet printing apparatus according to claim 3, wherein each of the plurality of energy supply units is arranged along a transport direction of the tablet.
The tablet printing apparatus according to claim 3, wherein each of the plurality of energy supply units applies thermal energy to the tablet at different inclination angles.
The tablet printing apparatus according to claim 1 or 2, wherein the drying mechanism includes a laser unit that irradiates the tablet with laser light and applies thermal energy to the tablet.
The tablet printing apparatus according to claim 6, wherein the laser unit includes an optical unit that collects and diffuses a laser beam irradiated toward the tablet at a predetermined point between the tablet and the tablet.
The drying mechanism includes an energy supply unit that outputs energy toward the transport belt at the drying position;
A shutter mechanism that does not cut off the energy output from the energy supply unit when the tablet passes through the drying position and cuts off the energy when the tablet does not pass through the drying position. The tablet printing apparatus according to claim 1, comprising:
The tablet printing apparatus according to any one of claims 1 to 8, wherein the drying mechanism gives thermal energy to the tablet when the tablet is printed.
The tablet printing apparatus according to any one of claims 1 to 9, further comprising an ink preheating mechanism for preheating ink droplets ejected from a plurality of nozzles of the inkjet head before reaching the tablet.
The tablet printing apparatus according to any one of claims 1 to 10, further comprising a cooling mechanism for cooling the transport belt in a region downstream of the drying position in the tablet transport direction.
The tablet printing apparatus according to any one of claims 1 to 11, wherein a heat radiation paint is applied to a surface of the conveyor belt.
A transport step of moving the transport belt and transporting sequentially supplied tablets;
A tracking step of detecting the position of the tablet on the transport belt and tracking the transport position;
A printing step in which printing is performed by ejecting ink droplets onto the tablet from an inkjet head having a plurality of nozzles that eject ink droplets when the tablet whose transport position is tracked in the tracking step is at the printing position. When,
When the tablet whose transport position is tracked in the tracking step passes a drying position downstream of the printing position in the transport direction of the tablet, energy is output toward the tablet, and the tablet is dried. A tablet printing method comprising: a drying step that outputs no energy toward the tablet when it does not pass through the position, or outputs less than an output when the tablet passes through the dry position.