Conveyance conveyor, and tablet processor

Abstract

To provide a technique for a conveyance conveyor for conveying granular material, capable to preventing a conveyor belt from being charged due to sliding contact between a support member and the conveyor belt.SOLUTION: A conveyance conveyor 25 comprises a pair of pulleys 26, and an annular conveyor belt 27 bridged to the pair of pulleys 26. The conveyor belt 27 rotates in response to rotation of the pair of pulleys 26 while holding granular material on an outer face thereof. The conveyance conveyor 25 comprises a support member 29. The support member 29 supports the annular conveyor belt 27 between the pair of pulleys 26, while coming into sliding contact with an inner face of the conveyor belt 27. The support member 29 is a conductive member. In this manner, static electricity generated by bringing the support member 29 into sliding contact with the conveyor belt 27 can be discharged onto the support member 29. Thus, the conveyor belt 27 can be prevented from being charged.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a transport conveyor for transporting granular material and a tablet processing device equipped with the transport conveyor. [Background technology]

[0002] Conventionally, there is known a printing device that prints on the surface of granular materials such as tablets and tablet candies. A conventional printing device is described, for example, in Patent Document 1. The printing device of Patent Document 1 prints an image on the surface of each tablet by an inkjet method while conveying a plurality of tablets on a conveyor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2023-026333 A Summary of the Invention [Problem to be solved by the invention]

[0004] The transport conveyor of this type of printing device has a support member that supports the belt. The support member supports the circular belt from the inside between a pair of pulleys. However, since the support member is in sliding contact with the transport belt, static electricity may be generated between the support member and the transport belt. This static electricity may cause the transport belt to become charged.

[0005] When the conveyor belt is charged, the tablets may tilt or the tablets may be transported improperly. Also, when tablet powder adheres to the conveyor belt, the tablet inspection results may be inaccurate. Furthermore, when tablet powder carrying static electricity adheres to the print head, ink ejection from the print head may be improper.

[0006] The present invention has been developed in consideration of the above circumstances, and aims to provide a technology that can prevent the conveying belt from becoming electrically charged due to sliding contact between a support member and the conveying belt in a conveyor that transports granular material. [Means for solving the problem]

[0007] In order to solve the above problems, the first invention of the present application is a transport conveyor for transporting granular material, comprising a pair of pulleys, a circular transport belt that is stretched across the pair of pulleys and rotates as the pulleys rotate while holding the granular material on its outer surface, and a support member that supports the transport belt between the pair of pulleys while sliding against the inner surface of the transport belt, the support member being a conductive member.

[0008] A second aspect of the present invention is the transport conveyor of the first aspect, wherein the support member is made of a conductive resin.

[0009] A third aspect of the present invention is the transport conveyor of the first or second aspect of the present invention, wherein the volume resistivity of the support member is 10 Ω·cm or more and 10 12 Ω·cm or less.

[0010] A fourth aspect of the present invention is the transport conveyor according to any one of the first to third aspects, wherein the transport belt is made of resin.

[0011] The fifth invention of the present application is a conveying conveyor according to any one of the first to fourth inventions, wherein the pulley has a plurality of external teeth formed on its outer surface along the rotation direction of the pulley, and the conveying belt has a plurality of internal teeth formed on its inner surface along the movement direction of the conveying belt, and the external teeth and the internal teeth mesh with each other.

[0012] The sixth invention of the present application is a conveying conveyor of any one of the first to fifth inventions, wherein the conveying belt has suction holes or suction slits for adsorbing the granular material, and the support member has slits communicating with the suction holes.

[0013] A seventh aspect of the present invention is the conveyor according to any one of the first to sixth aspects, wherein the granular material is a tablet.

[0014] An eighth aspect of the present invention is a tablet processing device, comprising: the transport conveyor of the seventh aspect of the invention; and a processing unit that performs at least one of printing and inspection on the tablets transported by the transport conveyor. Effect of the Invention

[0015] According to the first to eighth aspects of the present invention, static electricity generated by the sliding contact between the support member and the conveyor belt can be released to the support member side, thereby making it possible to suppress the charging of the conveyor belt.

[0016] In particular, according to the second aspect of the present invention, damage to the conveyor belt can be suppressed more effectively than when the support member is made of metal.

[0017] In particular, according to the third aspect of the present invention, the charging of the transport belt can be further suppressed.

[0018] In particular, according to the fourth aspect of the present invention, the conveyor belt can be processed more easily than when it is made of metal. Also, the number of parts can be reduced compared to when the conveyor belt is made of multiple types of materials, and the manufacturing cost of the conveyor belt and the cleanability of the conveyor belt can be improved.

[0019] In particular, according to the fifth aspect of the present invention, the rotation of the pulley can be transmitted to the conveyor belt with high accuracy.

[0020] In particular, according to the sixth aspect of the present invention, negative pressure can be applied to the suction holes or suction slits of the transport belt through the slits of the support member while maintaining the transport belt in sliding contact with the support member. [Brief description of the drawings]

[0021] [Figure 1] FIG. 1 is a diagram showing a configuration of a tablet printing device. [Diagram 2]FIG. [Diagram 3] FIG. [Figure 4] FIG. 2 is a control block diagram of the tablet printing device. [Diagram 5] FIG. 2 is an enlarged view of a portion of a pulley and a conveyor belt. [Figure 6] FIG. 3 is a diagram showing the transport conveyor of FIG. 2 with the transport belt removed. [Figure 7] FIG. 13 is a diagram showing the results of measuring the amount of charge on a conveyor belt when a non-conductive support member is used (Comparative Example) and when a conductive support member is used (Example). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0023] <1. Overall configuration of tablet printing device> FIG. 1 is a diagram showing the configuration of a tablet printing device 1 equipped with a transport conveyor 25 according to an embodiment. This tablet printing device 1 is a device that prints images such as a product name, a product code, a company name, and a logo mark on both sides of each tablet 9 while transporting a plurality of tablets 9, which are granular materials. The tablets 9 may be plain tablets (plain tablets), or may be coated tablets such as sugar-coated tablets and film-coated tablets (FC tablets). The tablets 9 may also be capsules, including hard capsules and soft capsules. The "granular materials" in the present invention are not limited to tablets as medicines, but may also be tablets as health foods or tablet candies such as Ramune.

[0024] As shown in FIG. 1, the tablet printing apparatus 1 of this embodiment includes a supply mechanism 10, a first drum 15, a second drum 20, a transport conveyor 25, a pre-printing imaging section 30, a printing section 35, a post-printing imaging section 40, a drying mechanism 45, an inversion mechanism 50, a discharge mechanism 55, and a control section 100.

[0025] The supply mechanism 10 is a mechanism that supplies a plurality of tablets 9 input into the tablet printing apparatus 1 to the first drum 15. The supply mechanism 10 of this embodiment has a bowl feeder 11, a first chute 12, a supply conveyor 13, and a second chute 14.

[0026] The bowl feeder 11 has a disk-shaped trough 110 that receives a plurality of tablets 9. The bowl feeder 11 vibrates the trough 110 to move the plurality of tablets 9 and supply them to the first chute 12. The first chute 12 extends in an arc between the trough 110 and the supply conveyor 13. The first chute 12 has a plurality of supply paths. The bowl feeder 11 supplies the tablets 9 to each supply path of the first chute 12. This causes a large number of tablets 9 to be aligned in a plurality of rows. That is, a plurality of rows of tablets 9 aligned in the conveying direction are formed in the width direction (direction perpendicular to the conveying direction). Then, the aligned tablets 9 are supplied from the first chute 12 to the supply conveyor 13. Note that only one row of tablets 9 is shown in FIG. 1.

[0027] The supply conveyor 13 is a mechanism for conveying the tablets 9 from the first chute 12 to the second chute 14. The supply conveyor 13 has two pulleys 131 and a circular supply belt 132 stretched around the two pulleys 131. One of the two pulleys 131 rotates by power obtained from a motor (not shown). This causes the supply belt 132 to rotate in the direction of the arrow in FIG. 1. The other pulley 131 rotates in response to the rotation of the supply belt 132. In addition, a partition plate extending along the boundary between rows of the tablets 9 is provided on the upper portion of the supply belt 132. The tablets 9 supplied from the first chute 12 are conveyed downstream in the conveying direction by the rotation of the supply belt 132 while being kept aligned in multiple rows by the partition plate.

[0028] The second chute 14 extends linearly between the supply conveyor 13 and the first drum 15. The second chute 14 has a plurality of horizontal supply paths. A plurality of tablets 9 supplied from the supply conveyor 13 are supplied to each supply path of the second chute 14. The tablets 9 in the second chute 14 are pushed by the succeeding tablets 9 conveyed by the supply conveyor 13, and are conveyed downstream in the conveying direction. Then, the tablets 9 are supplied from the end of the second chute 14 downstream in the conveying direction to the first drum 15.

[0029] The first drum 15 is a mechanism for holding and conveying a plurality of tablets 9 supplied from the second chute 14 at regular intervals in the conveying direction. The first drum 15 has a substantially cylindrical outer peripheral surface centered on a first axis O1 parallel to the width direction. A motor (not shown) is connected to the first drum 15. When the motor is driven, the first drum 15 rotates in the direction of the arrow in FIG. 1 around the first axis O1. The first drum 15 conveys the tablets 9 from a first transfer position P1 near the upper end of the first drum 15 to a second transfer position P2 adjacent to the second drum 20.

[0030] As shown in FIG. 1, the first drum 15 has a drum body 16 and a retaining ring 17. The drum body 16 has a cylindrical outer peripheral surface centered on a first axis O1. The drum body 16 is formed of a metal such as stainless steel. The retaining ring 17 is attached to the outer peripheral surface of the drum body 16. Specifically, a plurality of retaining rings 17 are arranged at widthwise positions corresponding to the respective rows of tablets 9. The retaining ring 17 is formed of a resin such as polyacetal.

[0031] The outer circumferential surface of each retaining ring 17 has a plurality of concave pockets 18. The plurality of pockets 18 are provided at regular intervals in the circumferential direction centered on the first axis O1. The retaining ring 17 also has suction holes 19 at the bottom of each pocket 18 for suctioning the tablets 9. The suction holes 19 are through-holes that penetrate the retaining ring 17.

[0032] The first drum 15 is connected to a suction mechanism (not shown). When the suction mechanism is operated, gas is sucked out from the internal space of the first drum 15 located in the angular range between the first delivery position P1 and the second delivery position P2. This causes the internal space to have a negative pressure lower than atmospheric pressure. In addition, negative pressure is also generated in the suction holes 19 communicating with the internal space. The tablets 9 supplied from the second chute 14 are sucked and held by the suction holes 19 of the holding ring 17 due to this negative pressure.

[0033] The tablets 9 supplied from the second chute 14 are accommodated in the pockets 18 one by one and are adsorbed and held in the suction holes 19. At this time, the tablets 9 are pressed by the pressing mechanism 141 to be guided into the pockets 18 of the holding ring 17. As a result, the intervals between the tablets 9 in the conveying direction become a predetermined interval corresponding to the intervals between the pockets 18. Each tablet 9 is conveyed from the first transfer position P1 to the second transfer position P2 by the rotation of the first drum 15 while being adsorbed and held in the suction holes 19 in the pockets 18. Then, when the tablet 9 passes the second transfer position P2, it leaves the angle range of the internal space maintained at the negative pressure, and the adsorption of the tablet 9 is released. As a result, the tablet 9 is delivered from the first drum 15 to the second drum 20.

[0034] The second drum 20 is a mechanism for transporting the tablets 9 delivered from the first drum 15 to the transport conveyor 25. The second drum 20 has a substantially cylindrical outer peripheral surface centered on a second axis O2 parallel to the width direction. In this embodiment, the outer diameter of the first drum 15 and the outer diameter of the second drum 20 are substantially the same. However, the outer diameter of the first drum 15 and the outer diameter of the second drum 20 may be different. A motor (not shown) is connected to the second drum 20. When the motor is driven, the second drum 20 rotates in the opposite direction to the first drum 15 around the second axis O2. The second drum 20 transports the tablets 9 from a second delivery position P2 adjacent to the first drum 15 to a third delivery position P3 adjacent to the transport conveyor 25. The height of the third delivery position P3 is higher than the heights of the first delivery position P1 and the second delivery position P2.

[0035] As shown in FIG. 1, the second drum 20 has a drum body 21 and a retaining ring 22. The drum body 21 has a cylindrical outer peripheral surface centered on the second axis O2. The drum body 21 is formed of a metal such as stainless steel. The retaining ring 22 is attached to the outer peripheral surface of the drum body 21. Specifically, the multiple retaining rings 22 are arranged at widthwise positions corresponding to the respective rows of tablets 9. The retaining ring 22 is formed of a resin such as silicone.

[0036] Each holding ring 22 has a plurality of suction holes 24. The suction holes 24 are through holes penetrating the holding ring 22. The second drum 20 is also connected to a suction mechanism (not shown). When the suction mechanism is operated, gas is sucked out from the internal space of the second drum 20 located in the angle range between the second delivery position P2 and the third delivery position P3. This causes the internal space to have a negative pressure lower than atmospheric pressure. In addition, a negative pressure is also generated in the suction holes 24 communicating with the internal space. The tablets 9 delivered from the first drum 15 are sucked and held by the suction holes 24 of the holding ring 22 due to this negative pressure.

[0037] The tablet 9 adsorbed and held in the suction holes 24 is transported from the second delivery position P2 to the third delivery position P3 by the rotation of the second drum 20. Then, when the tablet 9 passes the third delivery position P3, it leaves the angle range of the internal space maintained at the negative pressure, and the adsorption of the tablet 9 is released. As a result, the tablet 9 is delivered from the second drum 20 to the transport conveyor 25.

[0038] In this manner, in this embodiment, a plurality of tablets 9 supplied from the supply mechanism 10 are transported to the transport conveyor 25 via two drums, the first drum 15 and the second drum 20. The first drum 15 holds the plurality of tablets 9 at intervals in the transport direction. The second drum 20 transports the tablets 9 to the transport conveyor 25 while maintaining the intervals in the transport direction. At that time, the transport direction (rotation direction) of the tablets 9 is reversed between the first drum 15 and the second drum 20. This allows the tablets 9 to be sent from the second drum 20 to the transport conveyor 25 in accordance with the direction of operation of the transport conveyor 25.

[0039] The transport conveyor 25 is a mechanism for transporting the tablets 9 delivered from the second drum 20 while suction-holding them. The transport conveyor 25 has a pair of pulleys 26 and a circular transport belt 27 stretched around the pair of pulleys 26. One of the pair of pulleys 26 rotates by power obtained from a motor M. This causes the transport belt 27 to rotate in the direction of the arrow in FIG. 1. The other of the pair of pulleys 26 rotates following the rotation of the transport belt 27.

[0040] FIG. 2 is a partial perspective view of the transport conveyor 25. As shown in FIG. 2, a plurality of suction holes 270 are formed in the transport belt 27. The plurality of suction holes 270 are arranged at intervals in the transport direction and the width direction. Each suction hole 270 is a through hole penetrating the transport belt 27. The transport conveyor 25 also has a suction mechanism 28 that sucks out gas from the space inside the transport belt 27. When the suction mechanism 28 is operated, the space inside the transport belt 27 becomes a negative pressure lower than atmospheric pressure. The plurality of tablets 9 are sucked and held by the suction holes 270 one by one by the negative pressure.

[0041] In this manner, the tablets 9 are held on the outer surface of the transport belt 27 in a state aligned in the transport direction and the width direction. The transport conveyor 25 then rotates the transport belt 27 to transport the tablets 9 along the circular transport path. Below the pre-print imaging unit 30, the printing unit 35, and the post-print imaging unit 40, which will be described later, the tablets 9 are held on the upper surface of the transport belt 27 and transported in the horizontal direction.

[0042] As shown in FIG. 2, the surface of the conveyor belt 27 in this embodiment has a first region A1 that holds the tablets 9 before being inverted by the inversion mechanism 50, and a second region A2 that holds the tablets 9 after being inverted. The first region A1 and the second region A2 are adjacent to each other in the width direction. In this embodiment, the first region A1 and the second region A2 are provided with a plurality of suction holes 270 in three rows in the width direction. The tablets 9 transferred from the second drum 20 to the transport conveyor 25 are adsorbed and held by the suction holes 270 in the first region A1. In addition, the plurality of tablets 9 printed on both sides are discharged to the discharge mechanism 55 from the suction holes 270 in the second region A2.

[0043] The pre-printing imaging section 30 is a unit for photographing the tablets 9 before printing. The pre-printing imaging section 30 is located downstream of the conveying path from the third delivery position P3 described above and upstream of the conveying path from the printing section 35. The pre-printing imaging section 30 extends in the width direction across both the first area A1 and the second area A2. The pre-printing imaging section 30 photographs a plurality of tablets 9 conveyed by the conveyor belt 27. The images acquired by photographing are transmitted from the pre-printing imaging section 30 to the control section 100 described later. The control section 100 performs an appearance inspection of the tablets 9 based on the images obtained from the pre-printing imaging section 30. A more detailed configuration of the pre-printing imaging section 30 will be described later.

[0044] The printing unit 35 is a processing unit that prints an image on the surface of the tablet 9 conveyed by the conveyor belt 27 by an inkjet method. As shown in FIG. 1, the printing unit 35 of this embodiment has four heads 36. The four heads 36 are located above the conveyor belt 27 and are arranged in a row along the conveying direction of the tablet 9. Each head 36 extends in the width direction across both the first area A1 and the second area A2. The four heads 36 eject ink droplets of different colors (e.g., cyan, magenta, yellow, and black) toward the tablet 9. Then, a multicolor image is recorded on the surface of the tablet 9 by superimposing the monochromatic images formed by each of these colors. Note that the ink ejected from each head 36 is edible ink manufactured from raw materials approved by the Japanese Pharmacopoeia, the Food Sanitation Act, etc.

[0045] FIG. 3 is a bottom view of one head 36. In FIG. 3, the conveyor belt 27 and the plurality of tablets 9 held by the conveyor belt 27 are indicated by two-dot chain lines. As shown enlarged in FIG. 3, the bottom surface of the head 36 is provided with a plurality of nozzles 37 capable of ejecting ink droplets. In this embodiment, the plurality of nozzles 37 are two-dimensionally arranged in the conveying direction and the width direction on the bottom surface of the head 36. The nozzles 37 are arranged with their positions shifted in the width direction. In this way, by arranging the plurality of nozzles 37 two-dimensionally, the positions of the nozzles 37 in the width direction can be brought close to each other. However, the plurality of nozzles 37 may be arranged in a line along the width direction.

[0046] The method of ejecting ink droplets from the nozzle 37 is, for example, a so-called piezo method in which a voltage is applied to a piezo element to deform it, thereby pressurizing and ejecting the ink in the nozzle 37. However, the method of ejecting ink droplets may also be a so-called thermal method in which electricity is passed through a heater to heat and expand the ink in the nozzle 37, thereby ejecting the ink.

[0047] The post-printing imaging section 40 is a unit for photographing the tablets 9 after printing. The post-printing imaging section 40 is located downstream of the printing section 35 on the conveying path and upstream of the drying mechanism 45 on the conveying path. The post-printing imaging section 40 extends in the width direction across both the first area A1 and the second area A2. The post-printing imaging section 40 photographs the tablets 9 conveyed by the conveyor belt 27. The image acquired by photographing is transmitted from the post-printing imaging section 40 to the control section 100 described later. The control section 100 inspects the quality of the image printed on the tablets 9 based on the image obtained from the post-printing imaging section 40.

[0048] The drying mechanism 45 is a mechanism for drying the ink adhering to the tablet 9. The drying mechanism 45 is located downstream of the post-printing imaging unit 40 on the conveying path and upstream of the inversion mechanism 50 and the discharge mechanism 55 described later on the conveying path. The drying mechanism 45 extends in the width direction across both the first area A1 and the second area A2. For example, the drying mechanism 45 uses a hot air supply mechanism that blows heated gas (hot air) toward the tablet 9 conveyed by the conveyor belt 27. The ink adhering to the tablet 9 is dried by the hot air and fixed to the front or back surface of the tablet 9.

[0049] The inversion mechanism 50 is a mechanism that inverts the front and back of the tablet 9 conveyed by the conveyor belt 27 and moves the tablet 9 from the first area A1 to the second area A2. The inversion mechanism 50 is located downstream of the conveying path from the drying mechanism 45. The inversion mechanism 50 has a plurality of pairs of inclined drums 51 arranged in the width direction. Each inclined drum 51 has a conical holding surface. One of the pair of inclined drums 51 rotates while adsorbing the tablet 9 conveyed in the first area A1 to the holding surface, and transfers the tablet 9 to the other inclined drum 51. The other inclined drum 51 rotates while adsorbing the tablet 9 received from the one inclined drum 51 to the holding surface, and transfers the tablet 9 to the second area A2. As a result, the front and back of the tablet 9 are inverted and the tablet 9 moves from the first area A1 to the second area A2.

[0050] The tablet 9 conveyed from the supply mechanism 10 to the conveyor 25 via the first drum 15 and the second drum 20 is first held in the first area A1 of the conveyor belt 27. The tablet printing device 1 then conveys the tablet 9 while holding it in the first area A1, and performs the following processes on one side of the tablet 9: photographing by the pre-printing imaging unit 30, printing by the printing unit 35, photographing by the post-printing imaging unit 40, and drying by the drying mechanism 45. Next, the inversion mechanism 50 inverts the tablet 9 and moves it from the first area A1 to the second area A2. The tablet printing device 1 then conveys the tablet 9 while holding it in the second area A2, and performs the following processes on the other side of the tablet 9: photographing by the pre-printing imaging unit 30, printing by the printing unit 35, photographing by the post-printing imaging unit 40, and drying by the drying mechanism 45.

[0051] The discharge mechanism 55 is a mechanism for discharging a plurality of tablets 9 printed on both sides from the transport conveyor 25. The discharge mechanism 55 is located downstream of the transport path from the drying mechanism 45. The discharge mechanism 55 discharges the tablets 9 held in the second area A2 of the transport belt 27 below the transport conveyor 25 while separating the tablets 9 into defective tablets and non-defective tablets.

[0052] The control unit 100 is a unit for controlling the operation of each part in the tablet printing apparatus 1. FIG. 4 is a control block diagram of the tablet printing apparatus 1. As conceptually shown in FIG. 4, the control unit 100 is composed of a computer having a processor 101 such as a CPU, a memory 102 such as a RAM, and a storage unit 103 such as a hard disk drive. A computer program CP for carrying out transportation, printing, and inspection of the tablets 9 is stored in the storage unit 103.

[0053] As shown in FIG. 4, the control unit 100 is electrically connected to each of the bowl feeder 11, supply conveyor 13, first drum 15, second drum 20, transport conveyor 25, pre-print imaging unit 30, printing unit 35, post-print imaging unit 40, drying mechanism 45, inversion mechanism 50, and discharge mechanism 55 described above.

[0054] The control unit 100 temporarily reads out the computer program CP and data stored in the storage unit 103 into the memory 102, and the processor 101 performs arithmetic processing based on the computer program CP, thereby controlling the operation of each of the above-mentioned units. This allows the conveyance and printing of multiple tablets 9 to proceed. The control unit 100 also inspects the tablets 9 by processing images obtained from the pre-printing imaging unit 30 and the post-printing imaging unit 40 according to the computer program CP.

[0055] <2.About the transport conveyor> Next, the structure of the transport conveyor 25 will be described in more detail.

[0056] The conveyor belt 27 of the present embodiment is made of resin. For example, the conveyor belt 27 is made of resin such as urethane that is suitable for holding the tablets 9. Therefore, the conveyor belt 27 of the present embodiment is a non-conductive member.

[0057] By making the conveyor belt 27 from resin, the conveyor belt 27 can be made lighter than when it is made from metal. In addition, the conveyor belt 27 made from resin is easier to process than a conveyor belt made from metal. In addition, conventionally, conveyor belts have been made from two types of materials, namely, a metal such as stainless steel and a resin such as silicone. However, by forming the entire conveyor belt 27 from a single resin, the number of parts of the conveyor belt 27 can be reduced. In addition, by forming the entire conveyor belt 27 from a single resin, the manufacturing cost of the conveyor belt 27 and the cleanability of the conveyor belt 27 can be improved.

[0058] Fig. 5 is an enlarged view of a portion of the pulley 26 and the conveyor belt 27. As shown in Fig. 5, the pulley 26 has a plurality of external teeth 261 on its outer circumferential surface. The external teeth 261 are protrusions that protrude outward from the outer circumferential surface of the pulley 26. The plurality of external teeth 261 are formed at a constant pitch along the rotation direction of the pulley 26.

[0059] 5, the conveyor belt 27 has a plurality of internal teeth 271 on its inner surface. The internal teeth 271 are protrusions that protrude inward from the inner surface of the conveyor belt 27. The multiple internal teeth 271 are formed at a constant pitch along the moving direction of the conveyor belt 27. In this embodiment, since the conveyor belt 27 is made of resin, such multiple internal teeth 271 can be easily formed on the inner surface of the conveyor belt 27.

[0060] 5, the external teeth 261 of the pulley 26 and the internal teeth 271 of the conveyor belt 27 mesh with each other. This allows the rotation of the pulley 26 to be transmitted to the conveyor belt 27 with high precision. Therefore, the conveyor belt 27 can convey the tablets 9 with high precision.

[0061] Fig. 6 is a diagram showing the transport conveyor 25 of Fig. 2 without the transport belt 27. As shown in Fig. 1, Fig. 2, and Fig. 6, the transport conveyor 25 has a support member 29. The support member 29 is a member that supports the transport belt 27 between a pair of pulleys 26 while being in sliding contact with the inner surface of the transport belt 27.

[0062] The transport conveyor 25 of this embodiment has two support members 29. The two support members 29 are arranged at an interval in the vertical direction. The upper support member 29 contacts the lower surface (inner surface) of the transport belt 27 between the upper ends of the pair of pulleys 26. The lower support member 29 contacts the upper surface (inner surface) of the transport belt 27 between the lower ends of the pair of pulleys 26.

[0063] Each support member 29 extends along the inner surface of the conveyor belt 27. That is, the support members 29 are plates that extend in a plane along the conveying direction and the width direction. The conveyor belt 27 is conveyed between the pair of pulleys 26 while being supported by the support members 29. This suppresses the conveyor belt 27 from shaking or flapping in the up and down direction. In addition, the support members 29 suppress the conveyor belt 27 from being drawn inward by the negative pressure of the suction mechanism 28, thereby maintaining the shape of the conveyor belt 27.

[0064] As shown in FIG. 6, the support member 29 has a plurality of slits 291. The slits 291 are through holes that penetrate the support member 29 in the up-down direction. The plurality of slits 291 are arranged at intervals in the width direction of the conveyor belt 27. Each slit 291 extends linearly along the conveying direction of the tablet 9. The plurality of suction holes 270 of the conveyor belt 27 communicate with the internal space of the conveyor 25 through the slits 291. The negative pressure generated by the suction mechanism 28 acts on the suction holes 270 through the slits 291. This allows the conveyor belt 27 to be kept in sliding contact with the support member 29 while applying a negative pressure to the suction holes 270 of the conveyor belt 27.

[0065] However, since the conveyor belt 27 is in sliding contact with the support member 29, static electricity may be generated between the support member 29 and the conveyor belt 27 due to the sliding contact. In addition, in this embodiment, since the conveyor belt 27 is made of resin, static electricity generated between the support member 29 and the conveyor belt 27 cannot be released to the conveyor belt 27 side. Therefore, in this embodiment, the support member 29 is made of a conductive member. If the support member 29 is conductive, static electricity generated by the sliding contact between the support member 29 and the conveyor belt 27 can be released to the support member 29 side. This makes it possible to prevent the conveyor belt 27 from being charged.

[0066] Suppressing the charge on the conveyor belt 27 makes it possible to suppress tilting of the tablet 9 due to charging. It also makes it possible to suppress poor conveyance of the tablet 9 due to charging. It also makes it possible to suppress adhesion of fine powder of the tablet 9 to the outer surface of the conveyor belt 27. It also makes it possible to suppress adhesion of fine powder of the statically charged tablet 9 to the underside of the head 36. As a result, printing and inspection of the tablet 9 can be performed more accurately.

[0067] Metal or conductive resin may be used as the material of the support member 29. However, it is more preferable that the support member 29 is made of conductive resin. If the support member 29 is made of conductive resin, damage to the conveyor belt 27 can be suppressed more than if the support member 29 is made of metal.

[0068] In particular, in this embodiment, since the conveyor belt 27 is made of resin, if the support member 29 is made of metal, the difference in hardness between the support member 29 and the conveyor belt 27 will be large. In that case, the conveyor belt 27 will be easily damaged by sliding contact between the support member 29 and the conveyor belt 27. However, if the support member 29 is made of a conductive resin, damage to the conveyor belt 27 due to sliding contact can be reduced.

[0069] The volume resistivity of the support member 29 is, for example, 10 Ω·cm or more and 10 12 It is preferable that the volume resistivity of the support member 29 is 10 2 Ω cm or more and 10 4 It is preferable to set the resistivity to Ω·cm or less, which can further suppress the charging of the conveyor belt 27.

[0070] Fig. 7 is a diagram showing the results of measuring the amount of charge on the conveyor belt 27 when a non-conductive support member is used (comparative example) and when a conductive support member 29 is used (example) in the tablet printing apparatus 1. In the experiment of Fig. 7, polyacetal (POM) was used as the non-conductive resin. Also, in the experiment of Fig. 7, conductive ultra-high molecular weight polyethylene was used as the conductive resin.

[0071] "Row 1-3" in Fig. 7 represents the first area A1 in Fig. 2. "Row 4-6" in Fig. 7 represents the second area A2 in Fig. 2. "IJ4" in Fig. 7 represents the printing position by the head 36 on the most downstream side in Fig. 1. "IJ1" in Fig. 7 represents the printing position by the head 36 on the most upstream side in Fig. 1. "Drive pulley" in Fig. 7 represents the portion of the conveyor belt 27 that contacts the pulley 26 to which the motor M is connected, out of the pair of pulleys 26.

[0072] According to the results in Fig. 7, in all measurement positions, when a conductive support member 29 was used, the absolute value of the charge amount of the conveyor belt 27 was smaller than when a non-conductive support member was used. In particular, in positions "IJ4" and "IJ1" where the conveyor belt 27 is in direct contact with the support member 29, when a conductive support member 29 was used, the charge amount of the conveyor belt 27 was 0. This result shows that the charge amount of the conveyor belt 27 can be reduced by using a conductive member as the support member 29.

[0073] <3. Modifications> Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment. Various modified examples will be described below, focusing on the differences from the above embodiment.

[0074] In the above embodiment, the conveyor belt 27 is made of resin. However, the conveyor belt 27 may be made of a metal such as stainless steel. The conveyor belt 27 may be made of a plurality of parts made of different materials. The present invention is particularly useful when the conveyor belt 27 is made of resin, but even when the conveyor belt 27 is made of a material other than resin, the effect of suppressing charging of the conveyor belt 27 can be obtained by making the support member 29 conductive.

[0075] In the above embodiment, the support member 29 is made of a conductive resin. However, the support member 29 may be made of a metal.

[0076] In the above embodiment, the conveyor belt 27 has the suction holes 270 for suctioning the tablets 9. However, the conveyor belt 27 may have linear suction slits for suctioning the tablets 9 instead of the suction holes 270. The suction slits may communicate with the internal space of the transport conveyor 25 via the slits 291 of the support member 29.

[0077] In the above embodiment, the printing unit 35 is provided with four heads 36. However, the number of heads 36 included in the printing unit 35 may be one to three, or may be five or more.

[0078] In the above embodiment, the tablet printing device 1 that prints on the tablets 9 has been described. However, the present invention may be applied to a device that performs visual inspection on tablets, etc. That is, the present invention may be applied to a tablet processing device that includes a transport conveyor 25 and a processing section that performs at least one of printing and inspection on the tablets 9 transported by the transport conveyor 25.

[0079] Furthermore, the elements appearing in the above-described embodiment and modified examples may be appropriately selected to the extent that no contradiction occurs. [Explanation of symbols]

[0080] 1 Tablet printing equipment 9 tablets 10 Supply mechanism 15 First Drum 20 2nd Drum 25 Transport Conveyor 26 Pulley 27 Conveyor belt 28 Suction mechanism 29 Support member 30 Pre-printing imaging section 35 Printing Department 40 Post-printing imaging section 45 Drying mechanism 50 Reversal mechanism 55 Ejection mechanism 100 Control section 261 Outer teeth 270 Adsorption hole 271 Inner teeth 291 Slit A1 1st area A2 2nd area Medium motor

Claims

1. A conveyor for conveying granular material, A pair of pulleys; a circular conveyor belt that is stretched around the pair of pulleys and rotates with the rotation of the pulleys while holding the granular material on its outer surface; a support member that is disposed between the pair of pulleys and supports the conveyor belt while being in sliding contact with an inner surface of the conveyor belt; Equipped with The transport conveyor, wherein the support member is a conductive member.

2. 2. The transport conveyor according to claim 1, The support member is made of a conductive resin.

3. The transport conveyor according to claim 1 or 2, The volume resistivity of the support member is 10 Ω·cm or more and １２ A transport conveyor with a resistance of Ω·cm or less.

4. The transport conveyor according to claim 1 or 2, The transport belt is made of resin.

5. The transport conveyor according to claim 4, The pulley has a plurality of external teeth formed on an outer circumferential surface thereof along a rotation direction of the pulley, The conveyor belt has a plurality of internal teeth formed on an inner surface thereof along a moving direction of the conveyor belt, The external teeth and the internal teeth mesh with each other.

6. The transport conveyor according to claim 1 or 2, the conveyor belt has suction holes or suction slits for suctioning the particulate matter, The support member has a slit communicating with the suction hole.

7. The transport conveyor according to claim 1 or 2, A conveyor, wherein the granular material is tablets.

8. The transport conveyor according to claim 7; a processing unit that performs at least one of printing and inspection on the tablets transported by the transport conveyor; A tablet processing device comprising:

Images