Tablet printing device and method for attaching and detaching conveyor belt of tablet printing device

Abstract

To provide a tablet printing device and an attaching / detaching method for a conveyance belt of the tablet printing device capable of preventing deterioration in printing quality.SOLUTION: A tablet printing device 1 includes: a driving pulley 210 and a driven pulley 310; a conveyance belt 400; a printing head device 24 for executing printing on a conveyed tablet T; a first tensioner 520 provided so as to rotate between a stretched position R1 for applying tension by energizing the conveyance belt 400 with tension pulleys 510a and 510b, and a retreat position R2 where the energization is cancelled and the conveyance belt 400 can be detached; and a second tensioner 550 provided so as to rotate between a fixing position R3 where the first tensioner 520 is fixed to the stretched position R1 by a contact part 552 coming in contact, and a release position R4 where the first tensioner 520 can be moved to the retreat position R2 by the contact part departing.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] An embodiment of the present invention relates to a tablet printing device and a method for attaching and detaching a conveyor belt of the tablet printing device. [Background technology]

[0002] A tablet printing device described in Patent Document 1 has been known for some time. This tablet printing device sequentially conveys tablets that are held by suction on a conveyor belt using negative pressure. An inkjet printer, which is a printing device provided opposite the tablets on the conveyor belt, prints letters, marks, etc. for identification on the surfaces of the tablets.

[0003] Inkjet printers have a print head with multiple nozzles that eject ink droplets, which perform printing by ejecting ink droplets in accordance with a pattern based on print data.

[0004] When using such an inkjet printer, even if the characters or marks to be printed change due to a change in the type of tablet, it is possible to respond immediately by changing the print data provided. In addition, inkjet printers allow for contactless printing, which makes them hygienic and suitable for tablets that are intended for consumption. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2018-083701 Summary of the Invention [Problem to be solved by the invention]

[0006] The conveyor belt in such tablet printing machines comes into direct contact with tablets consumed by people, so it must be removed and cleaned regularly for sanitation. Even when changing the type of tablet, such as for non-potable detergent tablets, the conveyor belt must be removed and cleaned to prevent the remaining tablet components from mixing with the new tablet components. Furthermore, if the conveyor belt has storage compartments such as grooves or pockets for storing tablets, changing the tablet size requires the conveyor belt to be removed and replaced with one that has a storage compartment that fits the tablet size.

[0007] For this reason, conventionally, as shown in Figure 7, for example, a driven pulley C on the driven side around which the conveyor belt B is wound is provided so as to be movable horizontally by a guide mechanism G, and the tension of the conveyor belt B can be adjusted by moving the driven pulley C back and forth horizontally in accordance with the rotation of the ball screw S. In other words, the structure was such that by turning a knob H provided at the end of the ball screw S and moving the driven pulley C horizontally in one direction, tension was applied to the conveyor belt B so that it could convey tablets, and by moving it in the opposite direction, the biasing force on the conveyor belt B was weakened and relaxed so that it could be removed.

[0008] However, when tension is applied to the conveyor belt B by using the ball screw S to move the driven pulley C in the direction that biases the conveyor belt B, the amount of tension adjustment varies depending on the worker. Therefore, every time the conveyor belt B is attached, detached, or replaced, the tension of the conveyor belt B changes depending on the worker.

[0009] Tablet printing devices do not simply transport tablets; they also need to print on them with precision, so the position of the tablets must be stable during transport. If the tension fluctuates each time the transport belt B is replaced, the suction force applied to the tablets during transport becomes unstable, causing the tablets to shake or shift in position, resulting in printing defects such as double printing or misaligned printing.

[0010] In other words, in a tablet printing device, it is preferable that the tension of the conveying belt B be constant and stable, but unlike general printing devices for paper, etc., it was difficult to maintain a constant tension of the conveying belt B because the conveying belt B had to be frequently removed and cleaned.

[0011] Furthermore, the shaft of the driven pulley C is attached to the guide mechanism G via an elongated hole M, and the distance that the driven pulley C can move horizontally is limited to the horizontal length of this elongated hole M. For this reason, the amount of movement of the driven pulley C relative to the amount of rotation of the ball screw S is limited to the length of the elongated hole, and it took excessive time and effort to apply tension to the conveyor belt B. Moreover, the amount of retraction of the driven pulley C when removing or fitting the conveyor belt B was small compared to the effort, making it difficult to attach and remove.

[0012] The embodiments of the present invention have been proposed to solve the problems described above, and their purpose is to provide a tablet printing device and a method for attaching and detaching the conveying belt of a tablet printing device that can prevent a decline in print quality. [Means for solving the problem]

[0013] In order to achieve the above object, a tablet printing device according to an embodiment of the present invention includes a drive pulley and a driven pulley, an endless conveyor belt looped around the drive pulley and the driven pulley, a print head device that prints on tablets conveyed by the conveyor belt, a first tensioner that has a tension pulley that moves toward and away from the conveyor belt and is rotatable between a tensioned position where the tension pulley biases the conveyor belt to apply tension, and a retracted position where the biasing force on the conveyor belt is released to allow the conveyor belt to be removed, and a second tensioner that has a contact portion that moves toward and away from the first tensioner and is rotatable between a fixed position where the contact portion is brought into contact with the first tensioner to fix the first tensioner at the tensioned position, and a release position where the contact portion is moved away from the first tensioner to allow the first tensioner to move to the retracted position. a retraction positioning portion that positions the first tensioner at the retracted position, and a release positioning portion that positions the second tensioner at the release position;It has.

[0014] Furthermore, an embodiment of the present invention is a method for attaching and detaching a conveyor belt of a tablet printing device that uses a print head device to print on tablets conveyed by an endless conveyor belt that is wound around a drive pulley and a driven pulley, the method comprising: winding the conveyor belt around the drive pulley and the driven pulley; rotating a first tensioner provided with a tension pulley to move the tension pulley closer to a tensioned position where it applies tension to the conveyor belt; rotating a second tensioner to bring an abutting portion of the second tensioner into abutment with the first tensioner to fix the first tensioner to the tensioned position; attaching the conveyor belt to the drive pulley and the driven pulley by moving the second tensioner to a fixed position; and rotating the second tensioner from the fixed position to a release position so that the abutting portion is separated from the first tensioner; Positioning the second tensioner in the release position; The first tensioner is rotated to a retracted position where the tension on the conveyor belt is released and the conveyor belt can be removed. The first tensioner is positioned at the retracted position. The conveyor belt is then removed. [Effects of the Invention]

[0015] According to the embodiments of the present invention, it is possible to provide a tablet printing device and a method for attaching and detaching a conveyor belt of a tablet printing device that can prevent a decrease in tablet print quality. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a diagram schematically illustrating the overall configuration of a tablet printing apparatus according to an embodiment. FIG. [Figure 2] FIG. 1 is a diagram showing tablets placed on a conveyor belt as viewed from above. [Figure 3] FIG. 10 is a side view of the mounting portion of the first conveying device, showing the first tensioner in the tensioned position (A), and the first tensioner in the tensioned position and the second tensioner in the fixed position (B) with other components omitted. [Figure 4]FIG. 10 is a side view of the mounting portion of the first conveying device, showing the first tensioner in a temporary locking position (A), and the first tensioner in a temporary locking position and the second tensioner in a released position (B) with other components omitted. [Figure 5] FIG. 10 is a side view of the mounting portion of the first conveying device, showing the first tensioner in the retracted position (A), and the first tensioner in the retracted position and the second tensioner in the released position (B) with other components omitted. [Figure 6] 3A is a perspective view of the first tensioner and the second tensioner of FIG. 3A, and FIG. 5B is a perspective view of the first tensioner and the second tensioner of FIG. 5A. [Figure 7] FIG. 10 is a side view showing a conventional structure for applying tension to a conveyor belt. DETAILED DESCRIPTION OF THE INVENTION

[0017] An embodiment of the present invention will be described with reference to the drawings. In the following description, "up" and "down" refer to up and down in the vertical direction. The tablet T to be conveyed has, for example, a circular convex lens shape, and a pair of opposing dome-shaped curved surfaces are the printing target surfaces on which printing is performed.

[0018] 1, the tablet printing apparatus 1 of this embodiment includes a supply device 10, an alignment and conveyance device 11, a first printing device 20, a second printing device 30, a collection device 40, and a control device 50. The first printing device 20 and the second printing device 30 basically have the same structure.

[0019] As will be described later, the components of the tablet printing apparatus 1, namely, the supply device 10, the alignment and conveying device 11, the first printing device 20, the second printing device 30, and the recovery device 40, are arranged in this order. The tablets T supplied to the supply device 10 undergo a series of processes of printing and recovery while being conveyed along a conveying path. The conveying path is the route along which the tablets T are conveyed in the tablet printing apparatus 1, and in this embodiment, the supply device 10 is on the upstream side of the conveying path, and the recovery device 40 is on the downstream side.

[0020] [Feeding device] The supply device 10 is positioned at one end side of the aligning and conveying device 11, i.e., at one upstream end side of the conveying path P of the tablets T. The supply device 10 is electrically connected to the control device 50, and its driving is controlled by the control device 50.

[0021] The supply device 10 has a hopper 10a, a duct 10b, and a vibrating feeder (chute) 10c. The hopper 10a stores a large number of tablets T and sequentially supplies the stored tablets T to the duct 10b. The duct 10b is connected to the underside of the hopper 10a and supplies each tablet T supplied from the hopper 10a to the vibrating feeder 10c. The vibrating feeder 10c vibrates each tablet T supplied from the underside of the duct 10b to eliminate overlapping of the tablets T, while supplying each tablet T to the aligning and conveying device 11. In such a supply device 10, the tablets T fall and move due to their own weight, but for convenience in this specification, the supply device 10 will also be expressed as "conveying tablets T."

[0022] In this supply device 10, for example, 100,000 tablets T per hour (100,000 tablets / H) are fed into the hopper 10a, but not all of the tablets T fed into the hopper 10a immediately pass through the duct 10b and the vibrating feeder 10c and are fed to the aligning and conveying device 11. A large number of tablets T temporarily remain in the hopper 10a, the duct 10b, and the vibrating feeder 10c.

[0023] [Alignment and conveyance device] The aligning and conveying device 11 has an aligning feeder 13 and a transfer feeder 14. This aligning and conveying device 11 is positioned at one end side of the first printing device 20, i.e., at one upstream end side of the conveying path P. The aligning and conveying device 11 is configured to be able to supply tablets T to the first printing device 20 by the aligning feeder 13 and the transfer feeder 14. This aligning and conveying device 11 is electrically connected to the control device 50, and its drive is controlled by the control device 50.

[0024] The alignment feeder 13 aligns the supplied tablets T in two rows and transports them toward the transfer feeder 14. The transfer feeder 14 sequentially sucks in and holds each of the tablets T lined up in two rows on the alignment feeder 13 from above, transports the held tablets T in two rows to the first printing device 20, and delivers them to the first printing device 20. Note that as the alignment feeder 13 and the transfer feeder 14, for example, a belt conveying mechanism can be used.

[0025] [First printing device] The first printing device 20 includes a first conveying device 21, a detection device 22, a first imaging device (imaging device for printing) 23, a print head device 24, a second imaging device (imaging device for inspection) 25, and a drying device 26.

[0026] [First conveying device] The first conveying device 21 is a device that conveys tablets T by an endless conveying belt 400 that is wound around a driving pulley 210 and driven pulleys 310a and 310b. The first conveying device 21 rotates the conveying belt 400 together with the driven pulleys 310 by the rotation of the driving pulley 210 by the motor 220, and conveys the tablets T on the conveying belt 400 in a conveying direction A1 (clockwise direction).

[0027] The first conveying device 21 has a driving section 200, a driven section 300, a conveying belt 400, a mounting section 500, and a suction chamber 600, which are provided in a main body 21a. The main body 21a is a horizontally long housing including a frame.

[0028] (Drive unit) The drive unit 200 is provided at one horizontal end of the main body 21a and has a drive pulley 210, a motor 220, and a position detector 230. The drive pulley 210 is a pulley provided on the main body 21a so as to be rotatable about an axis perpendicular to the conveying direction A1. The motor 220 is connected to the shaft of the drive pulley 210 and is a drive source that rotates and drives the drive pulley 210. The motor 220 is electrically connected to the control device 50 and its operation is controlled by the control device 50.

[0029] The position detector 230 is a device such as an encoder, and is attached to the motor 220. The position detector 230 is connected to the control device 50 and transmits a detection signal to the control device 50. The control device 50, which will be described later, can obtain information such as the position, speed, and amount of movement of the conveyor belt 400 based on the detection signal.

[0030] (driven part) The driven unit 300 has a driven pulley 310 provided at the end of the main body 21a opposite to the drive unit 200. A plurality of driven pulleys 310 (two in the example of FIG. 1) are provided above and below. The two driven pulleys 310a, 310b are a pair of pulleys provided above and below the main body 21a and rotatable about an axis parallel to the axis of the drive pulley 210. The diameters and spacing of the pair of driven pulleys 310a, 310b and the diameter of the drive pulley 210 are set so that when the conveyor belt 400 is looped around the drive pulley 210 and the driven pulleys 310a, 310b, the upper and lower straight portions of the conveyor belt 400 are horizontal.

[0031] (Conveyor belt) The conveyor belt 400 is a strip-shaped body having a width parallel to the axes of the drive pulley 210 and the driven pulley 310. As shown in the plan view of Fig. 2, the conveyor belt 400 is formed with a plurality of suction holes 410 for sucking the tablets T by negative pressure. The suction holes 410 are circular through-holes, and are arranged in two parallel rows along the conveying direction A1 so as to form two conveying paths P. In Fig. 2, the conveying direction is the X direction, the horizontal width direction perpendicular to the conveying direction is the Y direction, and the rotation direction parallel to the XY plane is the θ direction.

[0032] In the following description, the term "attaching" refers to attaching the conveyor belt 400, "removing" refers to removing it, and "detaching" refers to both attaching and removing it.

[0033] (Attachment part) The mounting unit 500 mounts the conveyor belt 400 on the drive pulley 210 and the driven pulley 310, and applies the tension required for conveying the tablets T. As shown in Figures 3 to 6, the mounting unit 500 has a first tensioner 520, a temporary fixing portion 530, a retracted positioning portion 540, a second tensioner 550, a fixed positioning portion 560, and a released positioning portion 570. Figure 3 shows a state in which the first tensioner 520 is in the tensioned position R1 and the second tensioner 550 is in the fixed position R4, Figure 4 shows a state in which the first tensioner 520 is in the temporary fixing position R3 and the second tensioner 550 is in the released position R5, and Figure 5 shows a state in which the first tensioner 520 is in the retracted position R2 and the second tensioner 550 is in the released position R5.

[0034] The tensioned position R1 is a position where the tension pulleys 510a and 510b urge the conveyor belt 400 to apply tension that allows the tablets T to be conveyed. The retracted position R2 is a position where the urging force on the conveyor belt 400 is released, making it possible to remove the conveyor belt 400. The temporary fixing position R3 is a position where the first tensioner 520 is positioned near the tensioned position R1 in a state where tension is applied to the conveyor belt 400 only by the first tensioner 520. The fixed position R4 is a position where the second tensioner 550 fixes the first tensioner 520 to the tensioned position R1 by contacting the abutting portion 552 described below. The released position R5 is a position where the abutting portion 552 is released, making it possible to move the first tensioner 520 to the retracted position R2.

[0035] The first tensioner 520 is provided with tension pulleys 510a and 510b that come into contact with and separate from the conveyor belt 400, and is provided rotatably between a tensioned position R1, a retracted position R2, and a temporary fixing position R3.

[0036] The first tensioner 520 is provided on the main body 21a so as to rotate about a shaft 520a. The shaft 520a is provided near the upper driven pulley 310a and parallel to the axis of rotation of the driven pulley 310a. The tension pulleys 510a and 510b swing between the upper and lower driven pulleys 310a and 310b in accordance with the rotation of the first tensioner 520, adjusting the tension of the conveyor belt 400. The tension pulleys 510a and 510b, together with the driven pulleys 310a and 310b, also function as driven pulleys that are driven by the power of the drive pulley 210 transmitted via the conveyor belt 400.

[0037] In addition to the tension pulleys 510a and 510b described above, the first tensioner 520 of this embodiment also has a first rotating body 521, a lever 522, a first handle 523, and a first plunger 524. The first rotating body 521 is a substantially rectangular member, and tension pulleys 510a and 510b are rotatably mounted on both ends of the first rotating body 521 in the longitudinal direction. The upper end of the first rotating body 521 is mounted near the driven pulley 310a of the main body 21a so as to be rotatable about a shaft 520a.

[0038] Note that the rotation here refers to a change in angle around an axis parallel to drive pulley 210 and driven pulley 310, and moves tension pulleys 510a and 510b along an arc-shaped trajectory. For this reason, the rotation of first tensioner 520, that is, the rotation of first rotating body 521, differs from the rotation of ball screw S, which moves driven pulley C horizontally and linearly by rotating around an axis perpendicular to driven pulley C shown in Figure 7.

[0039] Furthermore, a notch 521a is formed in the corner of the first rotating body 521 facing the driven pulley 310b, against which a contact portion 552 of the second tensioner 550, described later, comes into contact. In other words, the notch 521a is a portion cut out to allow the contact portion 552 to fit therein, and has a linear edge with which the contact portion 552 comes into contact. When the first tensioner 520 is in the temporary fixing position R3, the second tensioner 550 rotates, thereby positioning the contact portion 552 in a position where it can come into contact with the notch 521a of the first rotating body 521.

[0040] Lever 522 is a substantially L-shaped member, one end of which is connected to shaft 520a, and is configured so that first rotating body 521 can rotate together with the rotation of lever 522. First handle 523 is a rod-shaped member provided on the other end of lever 522 so as to extend in a direction parallel to shaft 520a and toward the front of the page. An operator can grasp first handle 523 and rotate first rotating body 521 together with lever 522. In other words, first handle 523 enables manual operation to rotate first tensioner 520.

[0041] The second tensioner 550 is provided with an abutting portion 552 that comes into contact with and separates from the first tensioner 520, and is provided rotatable between a fixed position R4 (see FIG. 3) and a released position R5 (see FIGS. 5 and 6).

[0042] The second tensioner 550 is provided on the main body 21a so as to rotate about a shaft 550a that is different from the shaft 520a of the first tensioner 520. The shaft 550a is provided near the lower driven pulley 310b and is parallel to the axis of rotation of the driven pulley 310b.

[0043] The second tensioner 550 of this embodiment has a second rotating body 551, an abutment portion 552, a second handle 553, and a second plunger 554. The second rotating body 551 is a vertically elongated, approximately triangular member, and one end of its shorter side (base) is provided near the driven pulley 310b of the main body 21a so as to be rotatable about an axis 550a. Note that the rotation referred to here also refers to a change in angle about an axis parallel to the drive pulley 210 and the driven pulley 310. For this reason, the rotation of the second tensioner 550, i.e., the rotation of the second rotating body 551, differs from the rotation of the conventional ball screw S, which moves the driven pulley C horizontally and linearly by rotating about an axis perpendicular to the driven pulley C shown in FIG. 7.

[0044] The abutment portion 552 is located a predetermined distance back from the second rotating body 551 in the depth direction of the drawing in FIG. 3 and protrudes to the left of the drawing. In other words, the first rotating body 521 is located back from the second rotating body 551 in the depth direction of the drawing, and the abutment portion 552 is located at the same position as the first rotating body 521 in the depth direction of the drawing. Therefore, as shown in FIG. 5A, when the first tensioner 520 is in the retracted position R2, the first rotating body 521 and the tension pulley 510b are hidden behind a portion of the main body 21a and cannot be seen from the side. The tension position R1 of the first tensioner 520, which is determined by the contact of the abutment portion 552, is adjustable. In other words, the end position of the movement of the first tensioner 520, which is biased to rotate by the abutment portion 552, i.e., the tension position R1, is determined. Therefore, the tension position R1 can be changed by the contact portion 552, and the tension of the conveyor belt 400 by the tension pulleys 510a and 510b can be adjusted.

[0045] In this embodiment, the contact portion 552 is provided so that the biasing force of the outer edge of the contact portion 552 against the first tensioner 520 can be adjusted by adjusting the length of the protrusion from the second rotating body 551. As the protrusion length increases, the tension of the conveyor belt 400 increases, and as the protrusion length decreases, the tension of the conveyor belt 400 decreases. More specifically, the contact portion 552 is a roller provided so as to be rotatable about an axis parallel to the axis 550a. The roller is provided detachably on the second rotating body 551, so it can be replaced with a roller of a different diameter. By changing the diameter of the roller, the protrusion length of the contact portion 552 changes, and the tension of the conveyor belt 400 can be adjusted.

[0046] The contact portion 552 swings in accordance with the rotation of the second tensioner 550, and moves toward and away from the first tensioner 520. The location where the contact portion 552 of the first tensioner 520 moves toward and away from is the notch 521a, and the contact portion 552 fits into the notch 521a, preventing the contact portion 552 from shifting and enabling stable positioning.

[0047] Second handle 553 is a rod-shaped member provided at the vertex on the opposite side of second rotating body 551 from the short side so as to extend in a direction parallel to axis 550a and toward the front of the page. An operator can rotate second rotating body 551 by gripping second handle 553.

[0048] The first plunger 524 of the first tensioner 520 and the second plunger 554 of the second tensioner 550 will now be described with reference to FIG. 6. The first plunger 524 is equipped with a pin 524a that can be manually advanced and retreated parallel to the shaft 520a. As shown in FIG. 6(A), the temporary fixing portion 530 temporarily fixes the first tensioner 520 at a temporary fixing position R3, which is near the tensioned position R1 and where an abutment portion 552 of the second tensioner 550, described below, can abut (but has not yet abutted). The retracted positioning portion 540 positions the first tensioner 520 at the retracted position R2, as shown in FIG. 6(B).

[0049] More specifically, the temporary fixing portion 530 and the retraction positioning portion 540 are formed in a fixed member 21b fixed to the main body 21a, and are holes into which the pin 524a of the first plunger 524 can be inserted and removed. The temporary fixing portion 530 is a horizontally elongated hole that has play that allows the inserted pin 524a to move horizontally. By inserting the pin 524a into the temporary fixing portion 530, the first tensioner 520 is temporarily fixed at a temporary fixing position R3 near the tensioned position R1, but is allowed to move toward the tensioned position R1.

[0050] Temporarily fixed means that the first tensioner 520 is held in a predetermined position but can be moved by being biased, and the movable range is between the tensioned position R1 and the temporary fixed position R3. In this embodiment, the temporary fixed position R3 is near the tensioned position R1, but is a position where the tension pulleys 510a and 510b do not apply the tension necessary for conveying the tablet T. The retraction positioning portion 540 is a circular hole that restricts the movement of the inserted pin 524a. In other words, the diameter of the circular hole of the retraction positioning portion 540 is sized so that the first tensioner 520 cannot move from the retracted position R2 by inserting the pin 524a. As a result, the first tensioner 520 is fixed at the retracted position R2.

[0051] The second plunger 554 is a plunger equipped with a pin 554a that can be manually moved forward and backward parallel to the shaft 550a. The fixed positioning part 560 positions the second tensioner 550 at a fixed position R4, as shown in Figure 6(A). The release positioning part 570 positions the second tensioner 550 at a release position R5, as shown in Figure 6(B).

[0052] More specifically, the fixed positioning portion 560 and the release positioning portion 570 are formed on the fixed member 21c fixed to the main body 21a, and are holes through which the pin 554a of the second plunger 554 can be inserted and removed. The fixed positioning portion 560 and the release positioning portion 570 are circular holes that restrict movement of the inserted pin 554a. In other words, the diameters of the circular holes of the fixed positioning portion 560 and the release positioning portion 570 are sized so that inserting the pin 554a prevents the second tensioner 550 from moving from the fixed position R4 or the released position R5. As a result, the second tensioner 550 is fixed at the fixed position R4 or the released position R5.

[0053] (suction chamber) The suction chamber 600 is a container that applies suction force by negative pressure to each suction hole 410 of the conveyor belt 400. Each suction hole 410 is connected to the inside of the suction chamber 600 via a suction path provided in the suction chamber 600, and is able to obtain suction force from the suction chamber 600. An air suction device such as a pump is connected to the suction chamber 600 via an air suction pipe (neither is shown), and the pressure inside the suction chamber 600 is reduced by operating the air suction device. The air suction device is also electrically connected to the control device 50, and its operation is controlled by the control device 50.

[0054] The detection device 22 has a plurality of detection units 22a (two in the example of FIG. 2). The detection units 22a are arranged one by one for each conveyance path of the tablets T downstream in the conveyance direction A1 from the position where the tablets T are supplied on the conveyor belt 400 by the aligning and conveying device 11, in a direction intersecting (for example, perpendicular to) the conveyance direction A1 in the horizontal plane, and are provided above the conveyor belt 400. The detection units 22a detect the position of the tablets T on the conveyor belt 400 (position in the conveyance direction A1) and function as trigger sensors for each device located downstream. Various laser sensors such as reflective laser sensors can be used as the detection units 22a. Each detection unit 22a is electrically connected to the control device 50 and transmits a detection signal (position information) to the control device 50.

[0055] The first imaging device 23 has a plurality of imaging units 23a (two in the example of FIG. 2). The imaging units 23a are arranged downstream in the conveying direction A1 from the position where the detection device 22 is provided, in a direction intersecting (for example, perpendicular to) the conveying direction A1 in the horizontal plane, one for each conveying path of the tablets T, and are provided above the conveyor belt 400. Based on the position information of the tablets T described above, the imaging units 23a capture images when the tablets T arrive directly below the imaging units 23a, acquire images including the top surfaces of the tablets T (images for printing), and transmit the acquired images to the control device 50. The imaging units 23a can be various cameras having imaging elements such as CCDs (charge-coupled devices) and CMOSs ​​(complementary metal-oxide semiconductors). Each imaging unit 23a is electrically connected to the control device 50, and its operation is controlled by the control device 50. Incidentally, illumination for imaging is also provided as necessary.

[0056] The print head device 24 is a device that prints on the printing target surface of the tablet T. The print head device 24 of this embodiment has multiple inkjet print heads 24a (two in the example of Figure 2). The print heads 24a are arranged downstream in the conveying direction A1 from the position where the first imaging device 23 is provided, in a direction that intersects (e.g., a direction perpendicular to) the conveying direction A1 in the horizontal plane, one for each conveying path of the tablet T, and are provided above the conveying belt 400. The print head 24a has multiple nozzles 24b (see Figure 2; however, only four are shown in the illustration), and ejects ink individually from these nozzles 24b.

[0057] The print head 24a is arranged so that the alignment direction of the nozzles 24b intersects (for example, perpendicular to) the transport direction A1 in a horizontal plane. The print head 24a can be any inkjet print head having a driving element such as a piezoelectric element, a heating element, or a magnetostrictive element. Each print head 24a is electrically connected to a control device 50, and its driving is controlled by the control device 50.

[0058] The second imaging device 25 has a plurality of imaging units 25a (two in the example of FIG. 2). The imaging units 25a are arranged downstream in the conveying direction A1 from the position where the print head device 24 is provided, in a direction intersecting (for example, perpendicular to) the conveying direction A1 in the horizontal plane, one for each conveying path of the tablets T, and are provided above the conveyor belt 400. Based on the position information of the tablets T described above, the imaging units 25a capture images when the tablets T arrive directly below the imaging units 25a, and acquire images (images for inspection) including the top surfaces of the tablets T. The imaging units 25a then transmit the acquired images to the control device 50. As with the imaging unit 23a described above, various cameras having imaging elements such as CCDs and CMOSs ​​can be used as the imaging units 25a. Each imaging unit 25a is electrically connected to the control device 50, and its operation is controlled by the control device 50. Incidentally, illumination for imaging is also provided as necessary.

[0059] Returning to FIG. 1, the drying device 26 is positioned downstream in the conveying direction A1 from the position where the print head device 24 is provided, and is provided, for example, below the first conveying device 21. This drying device 26 is a drying device common to the two rows of conveying paths, and dries the ink applied to each tablet T on the conveying belt 400. As the drying device 26, various drying units can be used, such as a blower that dries using gas such as air, a heater that dries using radiant heat, or a blower that dries using warm or hot air using both gas and a heater. The drying device 26 is electrically connected to the control device 50, and its operation is controlled by the control device 50.

[0060] The tablets T that have passed above the drying device 26 are transported along with the movement of the conveyor belt 400, and reach a position near the end of the conveyor belt 400 on the side of each driven pulley 310. At this position, the suction action no longer acts on the tablets T, and the tablets T are released from the state held by the conveyor belt 400 and are transferred from the first printing device 20 to the second printing device 30.

[0061] [Second printing device] The second printing apparatus 30 includes a second conveying device 31, a detecting device 32, a first imaging device (imaging device for printing) 33, a print head device 34, a second imaging device (imaging device for inspection) 35, and a drying device 36. Similar to the first printing apparatus 20, the second conveying device 31 includes a driving unit 200, a driven unit 300, a conveying belt 400, a mounting unit 500, and a suction chamber 600. Each element constituting the second printing apparatus 30 has basically the same structure as the corresponding component of the first printing apparatus 20 described above, and therefore a description thereof will be omitted. The conveying direction of the second printing apparatus 30 is conveying direction A2 (counterclockwise), which is the direction of arrow A2 in FIG. 1.

[0062] [Recovery Device] The recovery device 40 includes a defective product recovery device 41 and a non-defective product recovery device 42. This recovery device 40 is provided downstream in the conveying direction A2 from the position where the drying device 36 of the second printing device 30 is provided, and the defective product recovery device 41 recovers defective tablets T, and the non-defective product recovery device 42 recovers non-defective tablets T. Note that the defective tablets T are, for example, tablets T having cracks, chips, or stains detected based on images acquired by the imaging devices 23 and 33, tablets T whose positional deviation before printing exceeds an allowable value, tablets T from which part or all of the printed identification information is missing, or tablets T whose printing position exceeds an allowable value detected based on images acquired by the second imaging device 25 and the second imaging device 35.

[0063] The defective product recovery device 41 has a spray nozzle 41a and a storage device 41b. The spray nozzle 41a is provided in the suction chamber 600 of the second printing device 30. This spray nozzle 41a sprays gas (e.g., air) toward the tablets T (defective tablets T) conveyed by the conveyor belt 400, causing the tablets T to fall from the conveyor belt 400. At this time, the gas sprayed from the spray nozzle 41a passes through suction holes 410 (similar to the suction holes 410 shown in FIG. 2) of the conveyor belt 400 and hits the tablets T. The spray nozzle 41a is electrically connected to the control device 50, and its drive is controlled by the control device 50. The storage device 41b receives and stores the tablets T that have fallen from the conveyor belt 400.

[0064] The non-defective product collecting device 42 has a gas blowing section 42a and a storage device 42b. The non-defective product collecting device 42 is provided downstream of the position where the defective product collecting device 41 is provided in the conveying direction A2.

[0065] The gas blowing section 42a is provided in a location within the second conveying device 31 of the second printing device 30 where the suction action of the suction chamber 600 no longer works (i.e., the end of the conveying belt 400 on the driven pulley 310 side). The gas blowing section 42a constantly blows gas (e.g., air) toward the conveying belt 400 during, for example, the printing process, causing the tablets T to fall from the conveying belt 400. At this time, the gas blown out from the gas blowing section 42a passes through suction holes 410 (similar to the suction holes 410 shown in FIG. 2) of the conveying belt 400 and hits the tablets T. As the gas blowing section 42a, for example, an air blower having a slit-shaped opening extending in a direction intersecting (e.g., perpendicular to) the conveying direction A2 in a horizontal plane can be used. The gas blowing section 42a is electrically connected to the control device 50, and its drive is controlled by the control device 50.

[0066] Here, the tablets T that have passed through the defective product collecting device 41 are transported along with the movement of the conveyor belt 400, and reach a position near the end of the conveyor belt 400 on the side of each driven pulley 310. At this position, the suction action no longer acts on the tablets T, and by further providing the gas blowing section 42a, the tablets T can be dropped from the conveyor belt 400 into the storage device 42b.

[0067] The storage device 42b receives and stores the tablets T that have fallen from the underside of the conveyor belt 400. The storage device 42b is positioned at the downstream end of the conveyor belt 400, i.e., at the conveying end of the second conveyor device 31 in the second printing device 30.

[0068] [Control device] As shown in FIG. 1, the control device 50 includes an image processing unit 51, a print processing unit 52, an inspection processing unit 53, and a memory unit 54. The image processing unit 51 processes images. The print processing unit 52 performs processing related to printing. The inspection processing unit 53 performs processing related to inspection. The memory unit 54 stores various information such as processing information and various programs. Such a control device 50 controls the supply device 10, the alignment and conveying device 11, the first printing device 20, the second printing device 30, and the recovery device 40, and also receives position information of the tablets T transmitted from the individual detection devices 22, 32 of the first printing device 20 and the second printing device 30, and images transmitted from the individual imaging devices 23, 25, 33, 35 of the first printing device 20 and the second printing device 30.

[0069] [Removing and putting on the belt] Next, we will explain the detachment and installation work of the conveyor belt 400 of the first conveyor device 21 and the installation work of the conveyor belt 400 in the tablet printing apparatus 1. The detachment and installation work of the conveyor belt 400 in the second conveyor device 31 are similar. The method of attaching and detaching the conveyor belt 400 described below is also an aspect of the present invention.

[0070] (Removal work) First, as shown in Figures 3(A) and (B), the conveyor belt 400 is wrapped around the drive pulley 210 and driven pulleys 310a and 310b, and tension capable of transporting tablets T is applied by tension pulleys 510a and 510b. The following describes the process of removing the conveyor belt 400 from this state.

[0071] 4(A) and (B), the operator removes the pin 554a of the second plunger 554 from the fixed positioning portion 560 (see FIG. 6(A)), grips the second handle 553, and rotates the second rotating body 551 to rotate the second tensioner 550 to the release position R5. Then, the abutment portion 552 moves away from the notch 521a of the first rotating body 521, and the biasing force of the tension pulleys 510a and 510b of the first tensioner 520 on the conveyor belt 400 is weakened (temporarily fixed).

[0072] This causes the first tensioner 520 to rotate and reach the temporary fixing position R3. The operator then inserts the pin 554a of the second plunger 554 into the release positioning portion 570 (see FIG. 6(B)), thereby fixing the second tensioner 550 at the release position R5.

[0073] 5(A) and (B), the worker removes pin 524a of first plunger 524 from temporary fixing portion 530 (see FIG. 6(A)), grasps first handle 523, and rotates first rotating body 521 together with lever 522 to rotate first tensioner 520 to retracted position R2. Furthermore, the worker inserts pin 524a of first plunger 524 into retracted positioning portion 540 (see FIG. 6(B)), thereby fixing first tensioner 520 in retracted position R2.

[0074] This loosens the conveyor belt 400, and the tension pulleys 510a and 510b are fixed in a state where they are sufficiently retracted from the conveyor belt 400. In this state, the worker removes the conveyor belt 400 from the first conveyor device 21. This makes it possible to clean the removed conveyor belt 400 or replace it with a new conveyor belt 400.

[0075] (Installation work) Next, we will explain the operation of installing the conveyor belt 400. As described above, when the conveyor belt 400 is not installed, the first tensioner 520 is fixed at the retracted position R2, and the second tensioner 550 is fixed at the released position R5, as shown in Figures 5(A) and 5(B).

[0076] In this state, the worker loops the conveyor belt 400 around the drive pulley 210 and the driven pulleys 310a and 310b. At this time, the first tensioner 520 is in the retracted position R2, so the tension pulleys 510a and 510b of the first tensioner 520 are retracted from the inner circumferential surface of the conveyor belt 400.

[0077] 4(A) and (B), the worker removes pin 524a of first plunger 524 from retraction positioning portion 540 (see FIG. 6(B)), grips first handle 523, and rotates first rotating body 521 together with lever 522 to rotate tension pulleys 510a and 510b in a direction in which they come into contact with conveyor belt 400. Then, pin 524a of first plunger 524 is inserted into temporary fixing portion 530 (see FIG. 6(A)).

[0078] As a result, the first tensioner 520 is temporarily fixed at a temporary fixing position R3 near the tensioned position R1. At this time, as shown in Fig. 4(A), the tension pulleys 510a and 510b contact the conveyor belt 400, but do not apply a tension sufficient to convey the tablets T.

[0079] Next, as shown in Figures 3(A) and (B), the operator removes pin 554a of second plunger 554 from release positioning portion 570 (see Figure 6(B)), and then grasps second handle 553 to rotate second rotating body 551 to a position where contact portion 552 contacts notch 521a of first rotating body 521. As a result, first tensioner 520, which is in temporary fixing position R3, is biased by contact portion 552 and rotates to tensioned position R1.

[0080] Then, the conveyor belt 400 is urged by the tension pulleys 510a and 510b of the first tensioner 520, and the tension required for conveying the tablets T is applied. Then, the pin 554a of the second plunger 554 is inserted into the fixed positioning portion 560 (see FIG. 6(A)). As a result, the second tensioner 550 is fixed to the fixed position R4, and the first tensioner 520 is also fixed to the tensioned position R1. Therefore, the conveyor belt 400 is ready to convey the tablets T.

[0081] [Printing Processing] 1 and 2, the printing process performed by the tablet printing apparatus 1 will now be described. First, various information such as print data required for printing is stored in the memory unit 54 of the control device 50. Then, when a large number of tablets T to be printed are placed in the hopper 10a of the supply device 10, the tablets T flow from the hopper 10a into the duct 10b. The tablets T that flow into the duct 10b begin to be sequentially supplied to the alignment feeder 13 by the vibration feeder 10c, and are moved in two rows by the alignment feeder 13. The tablets T moving in these two rows are sequentially supplied to the conveyor belt 400 of the first printing apparatus 20 by the transfer feeder 14.

[0082] The conveyor belt 400 rotates in the conveying direction A1 by the rotation of the drive pulley 210 driven by the motor 220, which in turn rotates the driven pulleys 310a, 310b and the tension pulleys 510a, 510b. Therefore, the tablets T supplied onto the conveyor belt 400 are lined up in two rows on the conveyor belt 400 and conveyed at a predetermined moving speed. Note that the conveyor belt 400 of the second printing device 30 also rotates in the conveying direction A2 by the rotation of the drive pulley 210 driven by the motor 220.

[0083] In the first printing device 20, the tablet T on the conveyor belt 400 is detected by the detection device 22. As a result, position information of the tablet T (position in the conveying direction A1) is acquired and input to the control device 50. This position information of the tablet T is stored in the memory unit 54 and used in post-processing.

[0084] Next, the tablets T on the conveyor belt 400 are imaged by the first imaging device 23 at a timing based on the position information of the tablets T described above, and the imaged images are transmitted to the control device 50. Based on the individual images transmitted from the first imaging device 23, positional deviation information of the tablets T (for example, positional deviation of the tablets T in the X direction, Y direction, and θ direction in FIG. 3) is generated by the image processing unit 51 and stored in the memory unit 54. Based on this positional deviation information of the tablets T, printing conditions for the tablets T (such as ink ejection position and ejection timing) are set by the print processing unit 52 and stored in the memory unit 54.

[0085] Next, printing is performed on each tablet T on the conveyor belt 400 by the print head device 24 based on the printing conditions described above at a timing based on the position information of the tablet T described above, i.e., at the timing when the tablet T reaches below the print head device 24. In each print head 24a of the print head device 24, ink is appropriately ejected from each nozzle 24b, and identification information such as letters (e.g., alphabets, katakana, numbers) and marks (e.g., symbols, figures) is printed on the top surface of the tablet T.

[0086] The tablet T on which the identification information is printed is imaged by the second imaging device 25 at a timing based on the position information of the tablet T described above, and the imaged image is transmitted to the control device 50. Based on the individual images transmitted from the second imaging device 25, printing position information indicating the printing position of the printing pattern for each tablet T is generated by the image processing unit 51 and stored in the memory unit 54. Based on the printing position information, the inspection processing unit 53 determines whether the printing on the tablet T is good or bad, and printing result information indicating the result of the printing quality for each tablet T is stored in the memory unit 54. For example, it is determined whether the printing pattern is printed at a predetermined position on the tablet T.

[0087] After inspection, the tablet T is transported along with the movement of the conveyor belt 400 and passes above the drying device 26. At this time, the ink that has reached (landed on) the tablet T is dried by the drying device 26 while the tablet T passes above the drying device 26, and the tablet T with the dried ink is transported along with the movement of the conveyor belt 400 and is positioned near the end of the conveyor belt 400 on the side of each driven pulley 310. At this position, the suction effect no longer acts on the tablet T, and the tablet T is released from the state held on the lower surface of the conveyor belt 400 and is passed from the first printing device 20 to the second printing device 30.

[0088] In the second printing device 30, the printing process and inspection process are performed in the same manner as described above. After inspection, the tablets T are transported as the conveyor belt 400 moves, and pass above the drying device 36. Then, the tablets T, on which the ink has dried, reach the defective product recovery device 41. At this position, the defective tablets T fall from the underside of the conveyor belt 400 due to the gas spray from the spray nozzle 41a, and are collected by the storage device 41b. On the other hand, the non-defective tablets T pass through the defective product recovery device 41 and reach the non-defective product recovery device 42. At this position, the suction action on the non-defective tablets T ceases to act on the tablets T, and the non-defective tablets T fall from the underside of the conveyor belt 400 due to the gas blown out by the gas blowing section 42a, and are collected by the storage device 42b.

[0089] [effect] (1) The tablet printing apparatus 1 of this embodiment as described above includes a drive pulley 210, a driven pulley 310, an endless conveyor belt 400 wound around the drive pulley 210 and the driven pulley 310, a print head device 24 that prints on tablets T conveyed by the conveyor belt 400, tension pulleys 510a and 510b, tension position R1 where tension pulleys 510a and 510b apply tension to the conveyor belt 400, and tension pulleys 510b at tension position R2 where tension pulleys 510a and 510b apply tension to the conveyor belt 400. The tensioner includes a first tensioner 520 that is rotatable between a first tensioner 520 and a retracted position R2 at which the tensioning force is released to allow the conveyor belt 400 to be removed, a second tensioner 550 that is provided with an abutting portion 552 that comes into contact with and separates from the first tensioner 520, and that is rotatable between a fixed position R4 at which the abutting portion 552 comes into contact to fix the first tensioner 520 at the tensioned position R1, and a release position R5 at which the abutting portion 552 moves away to allow the first tensioner 520 to move to the retracted position R2.

[0090] Furthermore, this embodiment is a method for attaching and detaching the conveyor belt 400 of the tablet printing apparatus 1, in which the conveyor belt 400 is looped around the drive pulley 210 and the driven pulley 310, and the first tensioner 520 is rotated to move the tension pulleys 510a and 510b closer to the tensioning position R1 where the conveyor belt 400 is biased to apply tension, and the second tensioner 550 is rotated to bring the abutting portion 552 into contact with the first tensioner 520, thereby applying tension to the first tensioner 520. The conveyor belt 400 is attached to the drive pulley 210 and the driven pulley 310 by moving the tensioner 520 to a fixed position R4 where it is fixed at the tensioning position R1, and the second tensioner 550 is rotated to a release position R5 so that the abutment portion 552 moves away from the first tensioner 520. The conveyor belt 400 is then removed by rotating the first tensioner 520 to a retracted position R2 where the force applied to the conveyor belt 400 is released and the conveyor belt 400 can be removed.

[0091] As mentioned above, due to hygiene issues specific to tablet printing, the conveyor belt 400 must be removed and cleaned daily in the tablet printing apparatus 1. In this embodiment, the operator can fix the first tensioner 520 in its fixed position, the tensioned position R1, by performing a two-step operation: rotating the first tensioner 520 and then rotating the second tensioner 550.

[0092] Therefore, the variation in tension applied to the conveyor belt 400 can be reduced compared to when the driven pulley C is moved back and forth by the rotation of the ball screw S. Therefore, even if the conveyor belt 400 is removed frequently, the tension can be stabilized, and printing defects caused by insufficient tension can be suppressed. Furthermore, since sufficient tension can be stably applied to the conveyor belt 400, slippage and slack in the conveyor belt 400 can be prevented, dust generation due to friction with other components can be suppressed, and printing defects can be reduced. In other words, a decrease in print quality can be prevented.

[0093] The rotation of the first tensioner 520 moves the tension pulleys 510a and 510b, and the rotation of the second tensioner 550 fixes the first tensioner 520, so that the necessary tension can be applied to the conveyor belt 400 with a light force using the principle of leverage, reducing the labor required for installation. Also, compared to when the driven pulley C is moved back and forth by the rotation of the ball screw S, the rotation of the first tensioner 520 ensures a large amount of retraction for the tension pulleys 510a and 510b, making it easier to remove the conveyor belt 400.

[0094] (2) This embodiment has a temporary fixing portion 530 that temporarily fixes the first tensioner 520 at a temporary fixing position R3 near the tensioned position R1 where the abutment portion 552 can abut. Therefore, when the tablet printing apparatus 1 is not in operation, the second tensioner 550 can be set to the release position R5 and the first tensioner 520 can be set to the temporary fixing position R3. Therefore, by resting the conveyor belt 400 (leaving the conveyor belt 400 looped around the drive pulley 210 and driven pulley 310 with a tension lower than that at which tablets T can be conveyed), the life of the conveyor belt 400 can be extended. When restarting the apparatus, the first tensioner 520 can be set to the tensioned position R1 by simply setting only the second tensioner 550 to the fixed position R4, which facilitates preparation work.

[0095] Furthermore, by setting the second tensioner 550 to the release position R5 and temporarily fixing the first tensioner 520 at the temporary fixing position R3, the conveyor belt 400 becomes less loose than when the first tensioner 520 is retracted to the retracted position R2. This allows the conveyor belt 400 to rest while avoiding interference with other components.

[0096] Furthermore, by temporarily fixing the first tensioner 520 in the temporary fixing position R3, the worker does not need to support the first tensioner 520, and the first tensioner 520 can be easily fixed in the tensioned position R1 by operating only the second tensioner 550. Therefore, even a single worker can perform the installation work.

[0097] (3) This embodiment includes the fixed positioning portion 560 that positions the second tensioner 550 at the fixed position R4. This allows the second tensioner 550 to more stably fix the first tensioner 520 at the tensioned position R1.

[0098] (4) The contact portion 552 is a rotatable roller, which allows the contact portion 552 in contact with the first tensioner 520 to move smoothly.

[0099] (5) The tension position R1 of the first tensioner 520, which is determined by the contact of the abutting portion 552, is adjustable. Therefore, the tension of the conveyor belt 400 can be adjusted by changing the tension position R1 using the abutting portion 552. For example, if the abutting portion 552 is a roller, the tension of the conveyor belt 400 can be adjusted by replacing it with a roller of a different diameter.

[0100] (6) This embodiment includes a retraction positioning unit 540 that positions the first tensioner 520 at the retraction position R2. Therefore, with the first tensioner 520 positioned at the retraction position R2 by the retraction positioning unit 540, the conveyor belt 400 can be easily removed without the need for support by an operator. This makes the removal work easy even for a single operator.

[0101] (7) This embodiment includes a release positioning portion 570 that positions the second tensioner 550 at the release position R5. Therefore, with the second tensioner 550 positioned at the release position R5 by the release positioning portion 570, the first tensioner 520 can be easily rotated without the need for support by an operator. This makes installation and removal easy even for a single operator.

[0102] (8) The first tensioner 520 has a first handle 523 that can be operated manually to rotate the first tensioner 520. Therefore, an operator can easily rotate the first tensioner 520 by gripping the first handle 523.

[0103] (9) The second tensioner 550 has a second handle 553 that can be operated manually to rotate the second tensioner 550. Therefore, an operator can easily rotate the second tensioner 550 by gripping the second handle 553.

[0104] (10) The conveyor belt 400 has suction holes 410 for sucking the tablets T by negative pressure. When the suction holes 410 are formed in the conveyor belt 400 and the tablets T are conveyed while being held by suction, if the tension of the conveyor belt 400 is not stable, the suction by the suction holes 410 will not be stable. However, in this embodiment, the tension can be easily maintained constant, so the suction of the tablets T is stable and printing defects due to poor holding of the tablets T are unlikely to occur.

[0105] [Variations] In the above description, two tension pulleys 510a, 510b apply tension to the conveyor belt 400, and the two tension pulleys 510a, 510b function as driven pulleys to stabilize the rotation of the conveyor belt 400. However, the number of tension pulleys is not limited to this and may be one, or three or more. Furthermore, because the tension pulley is also a driven pulley, it is also possible to have, for example, a tablet printing device that does not have any driven pulleys other than the tension pulley, that is, a device that only has a tension pulley and driven pulley.

[0106] In the above description, temporary fastening portion 530, retraction positioning portion 540, fixed positioning portion 560, and release positioning portion 570 are holes into which pin 524a of first plunger 524 and pin 554a of second plunger 554 are inserted and removed. However, temporary fastening portion 530, retraction positioning portion 540, fixed positioning portion 560, and release positioning portion 570 are not limited to this and may have any shape that allows pins 524a and 554a to be locked, such as a groove, notch, recess, or protrusion. Alternatively, first plunger 524 and second plunger 554 may be fixed to main body 21a, and holes for temporary fastening portion 530 and retraction positioning portion 540 may be provided in first tensioner 520, and holes for fixed positioning portion 560 and release positioning portion 570 may be provided in second tensioner 550.

[0107] In the above description, suction by the suction chamber 600 is performed on a portion of the conveyor belt 400, but suction by negative pressure may be performed over the entire length. The conveyor belt 400 may also have a storage section, such as a pocket, for storing tablets T. In this case, too, in this embodiment, it is easy to maintain constant tension, so the position of the storage section is stable, and printing defects due to incorrect storage of tablets T or misalignment are less likely to occur.

[0108] In the above description, the contact portion 552 is provided to protrude from the second tensioner 550, but the contact portion 552 may be configured to come into contact with and separate from a portion protruding from the first tensioner 520. For example, the contact portion 552 on the edge of the second tensioner 550 may be configured to come into contact with and separate from a roller that is rotatably provided on the first tensioner 520.

[0109] In the above explanation, an example is given in which the tablets T are transported in two rows, but this is not limited to this, and the number of rows may be one row or three or more rows, and there are no particular limitations on the number of transport paths or the number of transport belts 400. In addition, the shape of the suction holes 410 of the transport belt 400 is not limited to the example given above.

[0110] In the above explanation, an example was given of providing a print head 24a for each transport path for tablets T, but this is not limited to this, and for example, one print head 24a may be used to print on two or more rows of tablets T.

[0111] In the above explanation, a print head with nozzles 24b arranged in a single row was used as an example of the inkjet print head 24a, but this is not limited to this, and for example, a print head with nozzles 24b arranged in multiple rows may also be used.Furthermore, multiple print heads 24a may also be lined up along the transport direction A1.

[0112] In the above explanation, inkjet type print head devices are used as examples of print head devices 24 and 34, but this is not limited to this, and it is also possible to use transfer type print head devices that use, for example, a transfer roll or a transfer pad.

[0113] In the above explanation, an example was given of placing the first printing device 20 and the second printing device 30 one on top of the other to print on both sides or one side of the tablet T, but this is not limited to this, and for example, it is also possible to provide only the first printing device 20 and print on only one side of the tablet T.

[0114] The aforementioned tablets can include tablets used for pharmaceutical, food and beverage, cleaning, industrial, or aromatic purposes. Tablets include plain tablets (plain tablets), sugar-coated tablets, film-coated tablets, enteric-coated tablets, gelatin-coated tablets, multilayer tablets, and dry-coated tablets, and various types of capsule tablets, such as hard capsules and soft capsules, can also be included. Furthermore, in the above explanation, tablet T is exemplified as having a circular convex lens shape, but this is not limited thereto, and tablet shapes can include various shapes such as a disk, lens, triangle, oval, and rounded rectangle.

[0115] When the tablets to be printed are for medical or edible use, edible ink is suitable, and any of synthetic pigment ink, natural pigment ink, dye ink, and pigment ink may be used as the edible ink.

[0116] [Other embodiments] Although several embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0117] 1. Tablet printing equipment 10 Feeding device 10a Hopper 10b Duct 10c Vibration Feeder 11 Alignment and conveyance device 13 Alignment Feeder 14 Delivery Feeder 20 First printing device 21 Conveyor equipment 21a main body 21b, 21c fixing members 22 Detection device 22a Detector 23 First imaging device 23a Imaging unit 24 Print head unit 24a print head 24b nozzle 25 Second imaging device 25a Imaging unit 26 Drying equipment 30 Second printing device 31 Second conveying device 32 Detection device 33 First imaging device 34 Print head device 35 Second imaging device 36 Drying equipment 40 Recovery Device 41 Defective product recovery device 41a Injection nozzle 41b Containment device 42 Good product recovery device 42a Gas outlet 42b Containment Device 50 Control device 51 Image processing section 52 Print processing unit 53 Inspection processing section 54 Storage section 200 Drive Unit 210 Drive pulley 220 Motor 230 Position detector 300 Driven part 310, 310a, 310b driven pulleys 400 conveyor belt 410 Suction hole 500 Mounting part 510a, 510b tension pulley 520 First tensioner 520a shaft 521 1st rotation body 521a Notch 522 Lever 523 First Handle 524 First plunger 524a pin 530 Temporary fastening part 540 Evacuation positioning section 550 Second tensioner 550a shaft 551 2nd rotating body 552 Contact part 553 Second Handle 554 Second plunger 554a pin 560 Fixed positioning part 570 Release positioning part 600 suction chamber

Claims

1. a driving pulley and a driven pulley; an endless conveyor belt wound around the drive pulley and the driven pulley; a print head device that prints on the tablets transported by the transport belt; a first tensioner provided with a tension pulley that moves toward and away from the conveyor belt, the first tensioner being rotatable between a tensioned position where the tension pulley biases the conveyor belt to apply tension, and a retracted position where the biasing force on the conveyor belt is released to allow the conveyor belt to be removed; a second tensioner provided with an abutment portion that comes into contact with and separates from the first tensioner, and that is rotatable between a fixed position where the first tensioner is fixed to the tensioned position by bringing the abutment portion into contact with the first tensioner, and a release position where the abutment portion is moved away from the first tensioner to allow the first tensioner to move to the retracted position; a retraction positioning portion that positions the first tensioner at the retracted position; a release positioning portion that positions the second tensioner at the release position; A tablet printing device comprising:

2. 2. The tablet printing apparatus according to claim 1, further comprising a temporary fixing portion for temporarily fixing the first tensioner at a temporary fixing position near the tensioned position where the contact portion can contact.

3. 3. The tablet printing apparatus according to claim 1, further comprising a fixed positioning portion for positioning the second tensioner at the fixed position.

4. 4. The tablet printing apparatus according to claim 1, wherein the contact portion is a rotatable roller.

5. 5. The tablet printing device according to claim 1, wherein the tension position of the first tensioner, which is determined by the contact of the abutting portion, is adjustable.

6. 6. The tablet printing apparatus according to claim 1, wherein the tension pulley is the driven pulley.

7. A method for attaching and detaching a conveyor belt of a tablet printing device that prints on tablets conveyed by an endless conveyor belt wound around a drive pulley and a driven pulley using a print head device, comprising: The conveyor belt is wound around the drive pulley and the driven pulley, a first tensioner provided with a tension pulley is rotated to move the tension pulley toward a tensioned position where the tension pulley applies tension to the conveyor belt; By rotating the second tensioner, an abutting portion of the second tensioner abuts against the first tensioner, thereby fixing the first tensioner to the tensioned position, and by moving the second tensioner to a fixed position, the conveyor belt is attached to the drive pulley and the driven pulley, A method for attaching and detaching a conveyor belt of a tablet printing device, characterized in that the conveyor belt is removed by rotating the second tensioner from the fixed position to a release position so that the abutment portion moves away from the first tensioner, positioning the second tensioner at the release position, rotating the first tensioner to a retracted position that releases the force applied to the conveyor belt to allow the conveyor belt to be removed, and positioning the first tensioner at the retracted position.

Images