JP6611164B2 - Tablet printing apparatus and tablet printing method - Google Patents

Description

  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 conveyed by a conveyor belt.

  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) using a transfer roller on the surface of a solid preparation that is 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. A solid preparation contained in each pocket of the portion is fixed in the pocket. Thereby, it is transcribe | transferred (printed) by the transfer roller, without a character, a mark, etc. shifting to the solid formulation accommodated in each pocket. And the ink transcribe | transferred on the surface of each solid formulation is dried with the warm air dryer provided in the conveyance direction downstream of the solid formulation of the printing mechanism.

  In addition, from the viewpoint of ease of change of characters and marks and hygiene, instead of the printing mechanism using the transfer roller, it has a nozzle head having a plurality of nozzles for ejecting ink droplets, and follows a pattern based on printing data An ink discharge printing mechanism (so-called ink jet printer) that performs non-contact printing by discharging ink droplets from a plurality of nozzles of the nozzle head may be used.

JP-A-6-143539

By the way, when printing on a tablet using the ink discharge printing mechanism as described above, maintenance is performed by periodically discharging ink from the nozzle head in order to prevent ink clogging of each nozzle of the nozzle head. There is a need. Further , the posture of the tablet and the transport position may deviate from the planned positions. For example, in the case of an apparatus for storing and transporting a tablet in a pocket as shown in Patent Document 1, the tablet is stored so that the center of the tablet is not aligned with the center of the pocket and is moved in one direction. There are cases where the tablets are stored in an inclined state. Further, in an apparatus that does not have a pocket and adsorbs a tablet through a slit formed in the belt, the possibility that the transport position changes is higher than that in an apparatus that has a pocket. Printing is not performed when the tablet transport position is significantly deviated from the planned position, or when the tablet transport position is greatly inclined, but it is deviated from the planned position or posture, but within the allowable range. If it is included, the print data is adjusted, and ink droplets are ejected from a plurality of nozzles according to a pattern based on the adjusted print data. The nozzles used when the transport position is deviated, for example, rarely discharge ink as compared with the nozzles used when the tablets are transported to the predetermined positions. The nozzles of the nozzle head that are not ejected frequently may have ink dried and adhered around the nozzles, or the nozzles themselves may be clogged.If ink is ejected from such nozzles, the ink will bend. In some cases, the liquid is discharged or the discharge itself is impossible. Therefore, when printing on a tablet using an ink discharge printing mechanism, periodic nozzle maintenance for eliminating such dry ink is essential. In particular, the maintenance of discharging a small amount of ink from all the nozzles of the nozzle head (hereinafter referred to as “dummy discharge”) is periodically performed, thereby preventing discharge defects of nozzles that are not frequently used.

  However, in such regular maintenance of the nozzle head, if the maintenance is performed on the belt on which the tablet being transported is present, the tablet will be contaminated with ink by dummy ejection, so the nozzle head must be retracted to a predetermined position. In other words, the maintenance process takes time. In addition, when maintenance is performed without moving the nozzle head, all tablets in the transport mechanism must be discharged to prevent the tablets from becoming dirty, and the tablets can be transported to the printing position after maintenance. Takes a long time, and the loss time until the start of printing is large. A spare nozzle head is provided, and when one nozzle head is performing maintenance, printing on the tablet can be performed with the other nozzle head, but the means for moving the nozzle head becomes complicated, The cost will be high.

  The present invention has been made in view of such circumstances, and provides a tablet printing apparatus and a tablet printing method capable of efficiently performing maintenance for discharging ink from a nozzle head.

The tablet printing apparatus according to the present invention includes a pre-transport mechanism that transports sequentially supplied tablets, a transport belt that transports the tablets, a relay transport mechanism that takes the tablets from the pre-transport mechanism and delivers them to the transport belt. A transport mechanism having
A plurality of nozzles for ejecting ink droplets are provided, arranged opposite to the surface of the transport belt, and the ink droplets are ejected from the nozzles to a tablet at a printing position on the transport belt to perform printing on the tablets. An ink ejection printing mechanism to perform;
And the supply of tablets is stopped for said conveyor belt, have a sky area forming mechanism to form an empty area without tablets the conveyor belt,
The empty area forming mechanism is a relay interruption mechanism for retracting the relay transport mechanism from a position where the tablet can be received from the front transport mechanism to a position where the tablet cannot be received from the front transport mechanism,
When the sky area formed by the air-area forming mechanism passes through the printing position, a structure, characterized in that ink is ejected from all the nozzles of the ink ejection printing mechanism.

  With such a configuration, when the tablet transported by the transport belt passes the printing position, printing is performed on the tablet by ink droplets ejected from a plurality of nozzles of the nozzle head. Then, when the empty area formed on the conveyance belt passes through the printing position by the movement of the conveyance belt, ink droplets are ejected from all the nozzles of the nozzle head.

  According to the tablet printing apparatus according to the present invention, the printing on the tablets conveyed by the conveying belt is not stopped, the nozzle head is not particularly moved, and the tablets are not excluded from the conveying belt. Since ink droplets are ejected from all nozzles of the nozzle head to the empty area formed on the belt, maintenance of the nozzle head can be performed efficiently and at low cost.

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 top view which shows the tablet conveyed by the conveyance belt used for the tablet printing apparatus shown in FIG. It is a figure which shows typically the part which concerns on the 1st Embodiment of this invention in the tablet printing mechanism shown in FIG. It is a figure which shows typically the part (the 1) which concerns on the 2nd Embodiment of this invention in the tablet printing apparatus shown in FIG. It is a figure which shows typically the part (the 2) which concerns on the 2nd Embodiment of this invention in the tablet printing apparatus shown in FIG. It is a figure which shows typically the part which concerns on the 3rd Embodiment of this invention in the tablet printing apparatus shown in FIG. It is a figure which shows typically the modification of the 1st Embodiment of this invention in the tablet printing apparatus shown in FIG. It is a figure which shows an example of the relationship between the position fluctuation | variation of the printing area | region in the tablet conveyed, and the nozzle of a nozzle head. It is a figure which shows the other example of the relationship between the position fluctuation | variation of the printing area in the tablet conveyed, and the nozzle of a nozzle head. It is a side view which shows typically the tablet printing apparatus (mechanism part) of the state accommodated in the housing | casing case.

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

  The tablet which is the printing object of the tablet printing apparatus according to the present invention will be described by taking the tablet Tb as an example as an example, but the tablet is a bare tablet (uncoated tablet), a sugar-coated tablet, a film-coated tablet (FC tablet) Includes tablets and tablets such as enteric tablets, gelatin-encapsulated tablets, multilayer tablets, and dry-coated tablets, as well as capsule tablets such as hard capsules and soft capsules. For pharmaceutical use, food use, detergent use, industrial use, etc. , Regardless of its use.

  A tablet printing apparatus according to an embodiment of the present invention is configured as shown in FIG. In FIG. 1, a first oscillating feeder 12a and a second oscillating feeder 12b are continued from a hopper 11 for storing tablets to be printed, and an alignment feeder 14 is arranged further from the second oscillating feeder 12b. A first transport mechanism 17 is disposed behind the alignment feeder 14, and a delivery feeder 16 (relay transport mechanism) is provided 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. Has been placed. A second transport mechanism 18 is disposed below the first transport mechanism 17 so that the end portions overlap each other in the vertical direction. Further, return feeders 15 are arranged on both sides of the alignment feeder 14. In addition, the front conveyance mechanism is comprised by the 1st vibration feeder 12a and the 2nd vibration feeder 12b.

  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 delivered to the delivery feeder 16 sequentially. To do. The delivery feeder 16 has a structure in which a gas-permeable annular conveyance belt is wound around two pulleys (not shown), and an intake chamber coupled to an intake device (not shown) is provided inside the conveyance belt. .

  In the delivery feeder 16 (relay transport mechanism), the transport belt (relay transport belt) receives and transports the tablets Tb from the alignment feeder 14 by the intake action of the intake chamber (suction mechanism), and the intake action of the intake chamber is reduced. Delivered to the first transport mechanism 17 at a position where it does not work. The intake chamber of the delivery feeder 16 is provided on the lower surface of the delivery feeder 16. An intake chamber is not formed at the position of the delivery feeder 16 corresponding to the predetermined position so that the tablets are delivered to the predetermined position of the first transport mechanism 17. As a result, the suction action by the suction chamber of the delivery feeder 16 does not work at a predetermined position, and the tablet is delivered from the delivery feeder 16 to the first transport mechanism 17.

  The first transport mechanism 17 has a structure in which a transport belt 171 is wound around a drive pulley 172, a tension pulley 173, and two adjustment pulleys 174a and 174b. As shown in FIG. 2, the conveying belt 171 is aligned in two rows by the alignment feeder 14, and the moving direction of the conveying belt 171 corresponds to each row of tablets Tb supplied via the delivery feeder 16. Through holes 176 are provided so as to be arranged at predetermined intervals. The tablet Tb is adsorbed to the transport belt 171 by passing suction air through each through hole 176. The driving pulley 172 is driven by the motor M, and the annular conveying belt 171 rotates by the rotation of the driving pulley 172 accompanying the driving of the motor M. Further, a first encoder 45 that operates in accordance with the rotation of the drive shaft of the motor M is provided. An intake chamber 175 coupled to an unillustrated intake device (for example, a vacuum pump) via an exhaust port 175a is provided inside the annular conveyance belt 171. Due to the intake action of the intake chamber 175, air is sucked from the back side of the conveyor belt 171, whereby the tablets Tb are adsorbed and held on the surface of the conveyor belt 171 through the through holes 176.

  This tablet printer has a nozzle head with a plurality of nozzles that eject ink drops, and ejects ink drops from each nozzle by driving energy generating elements such as piezoelectric elements and thermal elements in accordance with the print data. Thus, an ink discharge printing mechanism (so-called inkjet printer) that performs printing is used. A nozzle head (referred to as a first nozzle head) 21 of the ink discharge printing mechanism is provided to face the surface of the conveyance belt 171. Further, around the transport belt 171, for example, a first tablet sensor 23 composed of a reflective optical sensor, a first posture confirmation camera 24, a first print confirmation camera 25, a first drying unit 27, and two Collection trays 28a and 28b are provided. In the intake chamber 175, two air injection nozzles 26a and 26b are provided so as to face the collection trays 28a and 28b with the conveyance 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 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 nozzle head 21, the first tablet sensor 23, the first posture confirmation camera 24, and the first printing described above. Two sets of the confirmation camera 25, the two air injection nozzles 26a and 26b, the first drying unit 27, 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 nozzle head 21 having 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 detects the tablet Tb on the transport belt 171 at 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. A detection signal based on the presence or absence is output. 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 imaging region of the first print confirmation camera 25 is set to a predetermined range on the downstream side of the printing position Pp in the moving direction D of the transport belt 171 (the transport direction D of the tablets Tb). The two air injection nozzles 26a and 26b and the two collection trays 28a and 28b are arranged below the intake chamber 175, that is, with the conveyance belt 171 stretched between the drive pulley 172 and the adjustment pulley 174b interposed therebetween. Has been. The collection tray 28a is provided to face the air injection nozzle 26a, and the collection tray 28b is provided to face the air injection nozzle 26b. A first drying unit 27 is disposed at a predetermined position upstream of the collection trays 28a and 28b so as to face the conveyor belt 171.

  The second transport mechanism 18 has substantially the same structure as that of the first transport mechanism 17 described above. Specifically, in the second transport mechanism 18, the transport belt 181 is wound around a drive pulley 182 driven by a motor M to which the second encoder 46 is attached, a tension pulley 183, and two adjustment pulleys 184a and 184b. An intake chamber 185 is provided which is connected to an intake device (not shown) via an exhaust port 185a inside the conveyor belt 181. Further, similarly to the conveyor belt 171, through holes are formed in the conveyor belt 181 at predetermined intervals in the moving direction of the conveyor belt 181. The tablet Tb is adsorbed and held on the transport belt 181 by suction of air through the through-hole due to the intake action of the intake chamber 185 based on the operation of the intake device (not shown). Around the transport belt 181, a second nozzle head 31 (print position Pp), a second tablet sensor 33 (tablet detection position Pd), a second posture confirmation camera 34, a second print confirmation camera 35 of the ink discharge printing mechanism, A second drying unit 37 and two collection trays 38a and 38b are provided. In the suction chamber 185, two air injection nozzles 36a and 36b are disposed so as to face the two collection trays 38a and 38b with the conveyance 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).

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

  As described above, the tablets Tb that are sequentially supplied from the hopper 11 and move through the first vibration feeder 12 a and the second vibration feeder 12 b reach the alignment feeder 14. Then, for example, the tablets Tb arranged in two rows are sequentially delivered to the first transport mechanism 17 by the delivery feeder 16 by the alignment feeder 14. The tablets Tb sequentially delivered to the first transport mechanism 17 by the delivery feeder 16 are sequentially transported while being attracted and held on the transport belt 171 in two rows (see FIG. 2).

  If the tablet Tb (located at the tablet detection position Pd) is detected on the basis of the detection signal from the first tablet sensor 23 in the process of transporting the tablets Tb in each row in the first transport mechanism 17, thereafter. Based on the value of the first encoder 45, the detected position of the tablet Tb with the tablet detection position Pd as a base point is recognized by the print control unit 100. When the tablet Tb enters the imaging region of the first posture confirmation camera 24, the first posture confirmation camera 24 takes a picture of a predetermined photographing range. Based on this photographed image, the tablet Tb is damaged, such as dirt or chips. Further, the posture of the tablet Tb determined to be undamaged on the transport belt 171 (front and back of the tablet Tb, position on the belt, orientation held on the belt, and vertical direction) (Including postures such as the inclination of). After that, when the tablet Tb determined not to be damaged passes through the printing position Pp, the first nozzle is generated 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 at a predetermined position on the surface of the tablet Tb in a predetermined direction. 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 first encoder 45).

  Further, when the tablet Tb that has undergone printing (printing position Pp) enters the imaging region of the first printing confirmation camera 25, the first printing confirmation camera 25 images a predetermined imaging range, and based on this captured image, the tablet Tb It is determined whether or not characters or marks are normally printed. 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 has passed through the imaging region of the first print confirmation camera 25 is transported as the transport belt 171 moves, and is printed on the surface when transported opposite the first drying unit 27. The printed character or mark ink is dried (fixed). The tablet Tb whose position is tracked by the printing control unit 100 without being printed due to damage such as chipping, and the tablet Tb that is not damaged such as chipping but has not been printed normally is one of When it reaches a position facing the air injection nozzle 26a, it is blown off from the conveyor belt 171 by the air injected from the air injection nozzle 26a and is recovered to the recovery tray 28a. Further, although there is no damage such as chipping, the tablet Tb whose printing is impossible due to a posture failure or the like and whose position is tracked by the printing control unit 100 reaches the position facing the other air injection nozzle 26b. The air is ejected from the conveyor belt 171 by the air ejected from the air ejection 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 as the transport belt 171 moves and transported from the transport belt 171 to the second transport mechanism 18 at a position where the suction action of the suction chamber 175 stops working. It falls on the 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 second tablet sensor of the tablets Tb sequentially transported as the transport belt 181 moves under the control of the print control unit 100. Position tracking based on the value of the second encoder 46 based on the output timing of the detection signal 33 (tablet detection position Pd), the back surface of each tablet Tb (surface opposite to the surface printed by the first transport mechanism 17) Printing of characters and marks by the second nozzle head 31 (positioned at the printing position Pp), drying of ink of characters and marks printed on the tablets by the second drying unit 37, damage and defective printing by the air jet nozzle 36a The tablet Tb with a certain amount is collected to the collection tray 38a, and the non-printable tablet Tb is collected to the collection tray 38b by the air injection nozzle 36b. Then, 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 185 does not work.

  Next, the configuration of the delivery feeder 16 in the tablet printing apparatus according to the embodiment of the present invention will be described in detail. In the embodiment of the present invention, due to the configuration of the delivery feeder 16, the above-described empty area for dummy discharge is placed on the first transport mechanism 17 (transport belt 171) or the second transport mechanism 18 (transport belt 181). Intentionally formed.

  In the tablet printing apparatus that performs the printing operation as described above, in the first embodiment, the alignment feeder 14 included in the front transport mechanism, the transfer feeder 16 as the relay transport mechanism, and the first transport mechanism 17 (transport belt 171). Is configured as schematically shown in FIG.

  In FIG. 3, as described above, the delivery feeder 16 has a configuration in which an annular conveyance belt 161 (relay conveyance belt) having gas permeability is wound around two pulleys. A sealing sheet 162 (relay interruption mechanism: tablet supply stop mechanism: empty area forming mechanism) that does not transmit gas is attached to a predetermined length portion of the conveyor belt 161, and the portion to which the sealing sheet 162 is attached is the non-adsorbable portion. It has become. Instead of forming the non-adsorbable portion on the conveyance belt 161 having gas permeability by sticking the sealing sheet 162, only the predetermined length portion does not have gas permeability, and other portions are gas. A conveyance belt 161 configured to have permeability may be used. For example, when the conveyance belt 161 having gas permeability by the fine holes is used, the non-adsorbable portion having no gas permeability can be formed by not forming the fine holes in the predetermined length portion.

  In such a delivery feeder 16, as described above, the transport belt 161 (relay transport belt) attracts and transports the tablets Tb from the alignment feeder 14 by the intake action of the intake chamber (not shown). The air is delivered to the first conveyance mechanism 17 (conveyance belt 171) at a position where the intake action stops working. In this process, the portion of the contact sheet 162 to which the tablet Tb from the alignment feeder 14 moves when the portion (non-adsorbable portion) to which the contact sheet 162 of the conveyor belt 161 is attached moves near the alignment feeder 14. Without being attracted to the carrier, it is dropped and returned to the upstream side of the alignment feeder 14 by the return feeder 15. For this reason, in the process in which the part to which the adhesion sheet 162 of the conveyance belt 161 is attached is moving close to the first conveyance mechanism 17, the tablet delivered from the delivery feeder 16 (conveyance belt 161) to the first conveyance mechanism 17. There is no Tb, and an empty area Ed having a length corresponding to the length of the sealing sheet 162 is formed on the upstream side of the printing position Pp in the transport direction D of the tablet Tb of the transport belt 171 of the first transport mechanism 17. The empty area Ed is, for example, the distance between the tablets Tb when the tablets Tb are arranged and conveyed at the shortest distance that can be continuously printed by the nozzle head 21 on the tablets Tb. The pitch is wider than the shortest arrangement pitch of the tablets Tb.

  The number of empty areas Ed formed on the transport belt 171 of the first transport mechanism 17 depends on the length and rotational speed of the transport belt 161 of the delivery feeder 16 and the length and rotational speed of the transport belt 171 of the first transport mechanism 17. It depends on the relationship. For example, the conveyance belt 161 of the delivery feeder 16 and the conveyance belt 171 of the first conveyance mechanism 17 are rotated synchronously at the same speed, and the entire length of the conveyance belt 171 of the first conveyance mechanism 17 is the same as that of the conveyance belt 161 of the delivery feeder 16. When the total length is three times, three empty areas Ed1, Ed2, and Ed3 are always formed at the same position on the rotating conveyor belt 171 of the first conveying mechanism 17 as shown in FIG.

The print control unit 100 (functional part of the dummy discharge control unit) prints the empty area Ed formed on the transport belt 171 based on the value of the first encoder 45 based on a predetermined rotation reference timing of the transport belt 171. The timing of passing through the position Pp can be recognized in advance. Then, while the empty area Ed passes through the printing position Pp, the print control unit 100 discharges ink from all the nozzles of the nozzle head 21 and performs dummy discharge. Since the amount of ink ejected from the nozzles by dummy ejection is very small, it can be dried by passing through the first drying unit 27 even if ejected onto the transport belt 171. In addition, since the intake chamber 175 is provided inside the transport belt 171, the ink discharged onto the transport belt 171 can be sucked and removed. In this case, the intake chamber 175 is preferably provided with a filter for preventing ink from entering. The print control unit 100, based on the detection signal from the first tablet sensor 23, also detect the empty areas Ed1, Ed2, Ed 3, each air based on the image captured by the first posture confirmation camera 24 Areas Ed1, Ed2, and Ed3 can also be detected. In this case, it is possible on the basis of the value of the detection results and the first encoder 45 of each empty area Ed1～Ed 3, calculated in advance the timing of the empty area Ed1~Ed3 passes the printing position Pp.

  According to the tablet printing apparatus (first embodiment) as described above, when the tablet Tb transported by the transport belt 171 of the first transport mechanism 17 passes the printing position Pp, a plurality of nozzle heads 21 are provided. Printing is performed on the tablet Tb by ink droplets discharged from the nozzle. Without stopping this flow, when each of the empty areas Ed1 to Ed3 intentionally formed on the transport belt 171 passes the printing position Pp, ink droplets are ejected from all the nozzles of the nozzle head 21. The dummy discharge of the nozzle head 21 can be efficiently performed without moving the head 21 from the conveyor belt 171 in particular.

  From the viewpoint that each empty area Ed on the rotating transport belt 171 passes through the printing position Pp, as described above, one or a plurality of empty areas Ed can be detected. It is preferable that the transport belt 171 of the first transport mechanism 17 is always formed at the same position. Further, when the empty area Ed is always formed at the same position, the ink absorbing material can be made with the position where the empty area Ed on the conveyor belt 171 is formed as a fixed place.

  Next, a second embodiment will be described.

  In the tablet printing apparatus shown in FIG. 1, in the second embodiment, the alignment feeder 14 included in the front transport mechanism, the transfer feeder 16 as the relay transport mechanism, and the first transport mechanism 17 (transport belt 171) are schematically illustrated. 4A and 4B.

  In this second embodiment, the delivery feeder 16 is not provided with the sealing sheet 162 of the first embodiment, and instead, as shown in FIGS. 4A and 4B, an elevation mechanism that moves the delivery feeder 16 up and down. 20 (retraction mechanism: relay interruption mechanism: tablet supply stop mechanism) is provided.

  The lifting mechanism 20 moves the delivery feeder 16 up and down between the operating position shown in FIG. 4A and the retracted position shown in FIG. 4B under the control of a drive control unit (not shown). In the state where the delivery feeder 16 is in the operating position, as described above, the transport belt 161 of the delivery feeder 16 can receive the tablets Tb from the alignment feeder 14 by the suction action of the suction chamber (suction mechanism). The received tablet Tb is transported and delivered to the first transport mechanism 17 at a position where the suction action of the suction chamber does not work. On the other hand, in the state where the delivery feeder 16 is in the retracted position, the tablet Tb conveyed from the alignment feeder 14 cannot be received by the delivery feeder 16. Therefore, the tablet Tb spills from the alignment feeder 14 and is returned to the upstream side of the alignment feeder 14 by the return roller 15. As a result, a vacant area Ed is formed on the upstream side of the printing position Pp in the tablet conveyance direction D of the conveyance belt 171 of the first conveyance mechanism 17, and the vacant area is sequentially moved by the movement of the conveyance belt 171.

  By adjusting the period and time during which the delivery feeder 16 is retracted from the operating position to the retracted position, the length and number of empty areas Ed formed on the conveyor belt 171 can be adjusted.

  As in the case of the first embodiment, the print control unit 100 applies the value to the conveyor belt 171 based on the value of the encoder 45, the detection signal from the first tablet sensor 23, and the image taken by the first posture confirmation camera 24. The timing when the formed empty areas Ed1 to Ed3 pass the printing position Pp is recognized, and ink is ejected from all the nozzles of the nozzle head 21 while the empty areas Ed1 to Ed3 pass the printing position Pp.

  According to the second embodiment as described above, each empty area Ed1 intentionally formed on the conveyor belt 171 in the process of printing on each tablet Tb, as in the first embodiment. When Ed3 passes the printing position Pp, ink droplets are ejected from all the nozzles of the nozzle head 21, so that the dummy ejection of the nozzle head 21 can be efficiently performed without specifically moving the nozzle head 21 from the transport belt 171. It can be performed.

  Next, a third embodiment will be described.

  In the tablet printing apparatus shown in FIG. 1, in the third embodiment, the alignment feeder 14 included in the front transport mechanism, the transfer feeder 16 as the relay transport mechanism, and the first transport mechanism 17 (transport belt 171) are schematically illustrated. As shown in FIG.

  In the third embodiment, as shown in FIG. 5, an air injection nozzle 163 (relay interruption mechanism: tablet removal mechanism: empty area formation mechanism) is provided inside the conveyance belt 161 having gas permeability of the delivery feeder 16. Is provided. The air injection nozzle 163 injects air from the air injection nozzle 163 at a predetermined cycle for a predetermined time under the control of an injection control unit (not shown). In the state where air is not ejected from the air ejection nozzle 163, as described above, the transport belt 161 of the delivery feeder 16 accepts and transports the tablets Tb from the alignment feeder 14 by the suction action of the suction chamber (suction mechanism). Then, the air is delivered to the first transfer mechanism 17 at a position where the air intake action of the air intake chamber does not work. On the other hand, in a state where air is being ejected from the air ejection nozzle 163, the tablet Tb delivered from the alignment feeder 14 to the transport belt 161 (delivery mechanism 16) is removed from the transport belt 161 by the air ejected from the air ejection nozzle 163. Blowed away. As a result, an empty area is formed on the upstream side of the printing position Pp in the transport direction D of the tablet Tb of the transport belt 171 of the first transport mechanism 17 corresponding to the portion of the transport belt 161 from which the tablet Tb has been removed. The empty area sequentially moves as the belt 171 moves.

  The length and number of empty areas formed on the conveyor belt 171 can be adjusted by adjusting the period and time during which air is ejected from the air ejection nozzle 163.

  As in the first and second embodiments, the print control unit 100 applies the value of the encoder 45, the detection signal from the first tablet sensor 23, and the image taken by the first posture confirmation camera 24. Based on this, the timings when the empty areas Ed1 to Ed3 formed on the transport belt 171 pass the printing position Pp are recognized, and while the empty areas Ed1 to Ed3 pass the printing position Pp, the nozzles 21 of the nozzle head 21 Ink is ejected.

  According to the third embodiment as described above, like the first embodiment and the second embodiment, in the process of printing on each tablet Tb, the conveyor belt 171 is intentionally provided. When the formed empty areas Ed1 to Ed3 pass the printing position Pp, ink droplets are ejected from all the nozzles of the nozzle head 21, so that the nozzle head 21 can be efficiently moved without being moved from the transport belt 171. In addition, dummy discharge of the nozzle head 21 can be performed.

  Next, a modification of the first embodiment will be described.

In the tablet printing apparatus shown in FIG. 1, in a modification of the first embodiment (see FIG. 3), as schematically shown in FIG. 6, the tablets Tb of the transport belt 171 of the first transport mechanism 17 are transported. A cloth ink removing roller 19 (ink removing portion) is provided in contact with the transport belt 171 at a predetermined position upstream from the position where the tablet Tb is delivered from the delivery feeder 16 in the direction D. As described above, by providing the ink removing roller 19, the ink that has been ejected from all the nozzles of the nozzle head 21 and adhered to the empty areas E d 1 to E d 3 of the conveying belt 171 is removed from the ink removing roller 19. Wiped off when passing through. Therefore, it is possible to prevent ink stains in the empty areas E d 1 to E d 3 from being accumulated due to long-time printing. As shown in FIG. 6, the ink removing roller 19 is a region where the suction chamber 175 of the transport belt 171 is not sucked (the transfer from the transport belt 171 to the transport belt 181 is completed, and then the tablet Tb is transferred from the transfer feeder 16 to the tablet Tb. It is preferable to provide a position opposite to the region until the undertaking. The material of the ink removing roller 19 is not limited to cloth, and may be any material that absorbs water, such as paper. Further, it may be always in contact with the transport belt 171 or may be in contact only at the timing when the empty area Ed is opposed. When contact is made only at the timing when the empty areas Ed face each other, even if the wiped ink is not completely absorbed by the ink removal roller 19, it prevents the other portions of the transport belt 171 from being stained. it can. Further, when the empty area Ed is fixed as described above, only the position of the empty area Ed on the transport belt 171 is increased, and only the empty area Ed is in contact with the ink removal roller 19. good.

  The modification shown in FIG. 6 is a modification of the first embodiment (see FIG. 3), but the second embodiment (see FIGS. 4A and 4B) and the third embodiment (FIG. 5). In the same manner, an ink removing roller 19 can be provided.

  Note that 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 in a state of being turned over so that the printed surface is on the transport belt 181 side. Also in the second transport mechanism 18, as in the case of the first transport mechanism 17, under the control of the print control unit 100, the back surface (first surface) of the tablets Tb that are sequentially transported as the transport belt 181 moves. Characters, marks, and the like are printed by the second nozzle head 31 (located at the printing position Pp) on the surface opposite to the surface printed by the first transport mechanism 17. In the process, the empty areas Ed1 to Ed3 formed on the conveying belt 171 of the first conveying mechanism 17 are taken over to the second conveying mechanism 18 as they are, and the empty areas Ed1 to Ed3 are formed on the conveying belt 181. Then, as in the case of the empty area formed on the conveyance belt 171, the print control unit 100 detects the nozzle head 31 when each empty area Ed <b> 1 to Ed <b> 3 passes the printing position Pd by the movement of the conveyance belt 181. Ink droplets are ejected from all ink nozzles. Thereby, dummy discharge of the nozzle head 31 in the second transport mechanism 18 can also be performed efficiently.

  In the tablet printing apparatus as described above, the tablet Tb (circular shape) delivered from the delivery feeder 16 to the transport belt 171 of the first transport mechanism 17 is, for example, an adsorption formed on the transport belt 171 as shown in FIG. The center of the tablet Tb is not necessarily arranged on the straight line CL on which the through-holes 176 are arranged. For this reason, the printing range Ep of each tablet Tb can be shifted in a direction orthogonal to the straight line CL in which the through-hole 176 is arranged, that is, the transport direction D (vertical direction in FIG. 7). Further, as shown in FIG. 8, when printing is performed on an elongated (unshaped) tablet Tb1, each tablet Tb1 is accurately positioned on a straight line CL on which suction holes 176 formed on the transport belt 171 are arranged. Even in the case where the nozzles NZ are arranged, the printing range Ep in the arrangement direction of the nozzles NZ of the nozzle head 21 varies depending on the orientation of the tablet Tb1. That is, the printing range Ep of each tablet Tb1 can be shifted in a direction orthogonal to the transport direction D (up and down direction in FIG. 8).

In the nozzle head 21, the nozzle NZ _C corresponding to the intersection of the print range Ep deviate to such orthogonal direction to the conveying direction D (vertical direction in FIG. 7 and FIG. 8) is in a state always ejected ink but for the nozzles NZ _R corresponding to the lower displacement portion of the upper displacement nozzle NZ _L and print area corresponding to a portion Ep of the print range Ep, low ejection frequency of the ink. For this reason, ink clogging may occur in the nozzles NZ _L and NZ _R whose ink ejection frequency is low during printing. However, as described above, since ink is ejected from all the nozzles in the empty areas Ed1 to Ed3 during the printing of the tablet Tb (Tb1), the nozzles NZ _R and NZ _L that are less frequently ejected during printing are used. It is possible to effectively prevent ink clogging.

In the tablet printing apparatus described above, the empty area forming mechanism that forms the empty areas E d 1 to E d 3 on the conveying belt 171 (181) of the first conveying mechanism 17 (second conveying mechanism 18) is the above-described first. The present invention is not limited to the first embodiment (see FIG. 3), the second embodiment (see FIGS. 4A and 4B), and the third embodiment (see FIG. 5). For example, a shutter (empty area forming mechanism) capable of opening and closing the path can be provided in a path connecting the intake chamber provided in the delivery feeder 16 to the intake device. In this case, if the shutter closes the path, the tablet Tb is not attracted to the transport belt 161 of the delivery feeder 16, and the tablet Tb is not delivered to the transport belt 171 of the first transport mechanism 17. This makes it possible to form an empty d rear without tablets conveyor belt 171.

Also, tablet printing apparatus above described (mechanism portion), as shown in FIG. 9, it is housed in the housing case 200. FIG. 9 is a side view schematically showing the tablet printing apparatus housed in the housing case 200.

  In FIG. 9, the tablet printing apparatus having the above-described structure (the same structure as FIG. 1) is housed in a generally box-shaped housing case 200. Each mechanism such as the alignment feeder 14, the delivery feeder 16, the first transport mechanism 17, and the second transport mechanism 18 is disposed at a location relatively close to the front wall portion of the housing case 200, and the suction of the first transport mechanism 17. A first intake pipe 207 that connects the chamber 175 (see FIG. 1) to an intake device (not shown) and a second intake air that connects the intake chamber 185 (see FIG. 1) of the second transport mechanism 18 to the intake device (not shown). Each of the tubes 208 extends to the back of the housing case 200. A transparent window 202 is fitted into a predetermined portion of the front wall portion of the case 200 so that the operator OPT can see the inside of the case 200 through the window 202. Further, a tray 209 that can be pulled out forward (on the side of the operator OP) is provided at the bottom of the housing case 200. The tray 209 may be divided into a plurality of parts in the horizontal direction of the housing case 200 (direction perpendicular to the paper surface of FIG. 9).

  As shown in FIG. 9, the mirror plate 210 that is obliquely inclined to the upper part in the housing case 200 is provided so as to face the window body 202, so that the operator OPT outside the housing case 200 Through the window body 202, the state of each mechanism (the first transport mechanism 17, the second transport mechanism 18, etc.) reflected on the mirror plate 210, the back side thereof, and the tablet transport state can be seen. For this reason, the operator OPT can easily visually check whether each mechanism has a problem while operating the tablet printing apparatus without stopping.

  Even if the tablet Tb falls from the delivery feeder 16, the first transport mechanism 17, and the second transport mechanism 18 to the bottom of the housing 200, the dropped tablet Tb is a tray provided at the bottom of the housing case 200. Received at 209. Therefore, the tablet Tb can be easily collected by pulling out the tray 209 from the housing case 200. When the tray 209 is divided as described above, only a tray that needs to be pulled out can be pulled out without pulling out a large tray over the entire bottom of the casing 200. In the third embodiment, the example in which the tablets Tb on the conveying belt 161 of the delivery feeder 16 are blown off by the air injection nozzle 163 has been described. However, the tablets Tb blown off at this time are returned to the return feeder. 15 recovered. However, even if it is not collected by the return feeder 15 due to the momentum of injection from the air injection nozzle 163, it can be recovered by the tray 209, which is efficient.

  In addition, the tray 209 accumulates adhered powder adhering to the tablet Tb together with the dropped tablet Tb. A vacuum cleaner that collects the deposited powder adhering to the bottom surface of the housing case 200 may be provided. The vacuum of this vacuum cleaner may use the suction source of the intake chamber 175 (185).

  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 14 Alignment feeder 15 Return feeder 16 Delivery feeder 17 1st conveyance mechanism 171 Conveyance belt 172 Drive pulley 173 Tension pulley 174a, 174b Adjustment pulley 175 Intake chamber 176 Through-hole 18 2nd conveyance Mechanism 181 Conveying belt 182 Drive pulley 183 Tension pulley 184a, 184b Adjustment pulley 185 Intake chamber 19 Ink removal roller 20 Lifting mechanism 21 First nozzle head 23 First tablet sensor 24 First posture confirmation camera 25 First print confirmation camera 26a, 26b Air spray nozzle 27 First drying units 28a, 28b Collection tray 31 Second nozzle head 33 Second tablet sensor 34 Second posture confirmation camera 35 Second print confirmation camera 36 a, 36b Air injection nozzle 37 Second drying unit 38a, 38b Collection tray 40 Storage tray 45 First encoder 46 Second encoder 100 Print control unit 200 Housing case 202 Window body 207 First intake pipe 208 Second intake pipe 209 Tray 210 Mirror plate

Claims (7)

A transport mechanism having a pre-transport mechanism that transports the tablets that are sequentially supplied, a transport belt that transports the tablets, and a relay transport mechanism that takes over the tablets from the front transport mechanism and delivers them to the transport belt ;
A plurality of nozzles for ejecting ink droplets are provided, arranged opposite to the surface of the transport belt, and the ink droplets are ejected from the nozzles to a tablet at a printing position on the transport belt to perform printing on the tablets. An ink ejection printing mechanism to perform;
And the supply of tablets is stopped for said conveyor belt, have a sky area forming mechanism to form an empty area without tablets the conveyor belt,
The empty area forming mechanism is a relay interruption mechanism for retracting the relay transport mechanism from a position where the tablet can be received from the front transport mechanism to a position where the tablet cannot be received from the front transport mechanism,
Wherein when the air the air area which is formed by the area forming mechanism passes through the printing position, tablet printing apparatus, characterized in that ink is ejected from all the nozzles of the ink ejection printing mechanism. A transport mechanism having a pre-transport mechanism that transports the tablets that are sequentially supplied, a transport belt that transports the tablets, and a relay transport mechanism that takes over the tablets from the front transport mechanism and delivers them to the transport belt;
A plurality of nozzles for ejecting ink droplets are provided, arranged opposite to the surface of the conveyance belt, and printing on the tablets is performed by ejecting ink droplets from the nozzles to the tablets at a printing position on the conveyance belt. An ink ejection printing mechanism to perform;
Said supply of tablets is stopped against the conveyor belt, it has a sky area forming mechanism Ru to form empty et rear no tablet to the conveyor belt,
The relay transport mechanism includes a relay transport belt capable of transporting tablets received from the front transport mechanism to the transport belt, and a suction mechanism for adsorbing the tablets received from the front transport mechanism to the transport belt to the relay transport belt; Have
The empty area forming mechanism is a non-adsorbable part that does not adsorb the tablets provided on the relay conveyance belt,
A tablet printing apparatus that discharges ink from all nozzles of the ink discharge printing mechanism when the empty area formed by the empty area forming mechanism passes through the printing position . The tablet printing apparatus according to claim 1 or 2, wherein the empty area formed by the empty area forming mechanism is always formed at the same position of the conveyor belt . The tablet printing apparatus according to claim 3 , wherein a material that absorbs the ink is provided at a position of the empty area on the transport belt . An ink removing unit that is provided at a position facing a region upstream of the conveyance direction from the position where the tablets are delivered from the relay conveyance mechanism on the conveyance belt and removes ink adhering to the empty area on the conveyance belt; The tablet printing apparatus according to any one of claims 1 to 4 .   A step of conveying the tablets sequentially supplied by a relay conveyance mechanism from a previous conveyance mechanism, and delivering the tablets received by the relay conveyance mechanism to a conveyance belt;
  When the tablets transported by the transport belt pass through a printing position on the transport belt, the ink is ejected from a plurality of nozzles to print the tablets.
  An empty area forming step of forming an empty area without the tablet on the transport belt on the upstream side of the printing position in the transport direction of the tablet, and
  In the empty area forming step, by retracting the relay conveyance mechanism to a position where the tablets cannot be received from the front conveyance mechanism, an empty area is formed on the conveyance belt that accepts tablets from the relay conveyance mechanism,
  A tablet printing method, wherein ink is ejected from all of the plurality of nozzles when an empty area formed by the empty area forming step passes through the printing position.   A step of conveying the tablets sequentially supplied by a relay conveyance mechanism from a previous conveyance mechanism, and delivering the tablets received by the relay conveyance mechanism to a conveyance belt;
  When the tablets transported by the transport belt pass through a printing position on the transport belt, the ink is ejected from a plurality of nozzles to print the tablets.
  An empty area forming step for forming an empty area without a tablet on a conveying belt on the upstream side of the printing position in the conveying direction of the tablet, and
  The empty area forming step includes providing a non-adsorbable portion where the tablet cannot be adsorbed on the relay conveyance belt that the relay conveyance mechanism has to adsorb the tablet and deliver it to the conveyance belt. Forming an area,
  A tablet printing method, wherein ink is ejected from all of the plurality of nozzles when an empty area formed by the empty area forming step passes through the printing position.

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