Tablet printing device and tablet printing method

Abstract

To suppress generation of a printing failure and deterioration in ink.SOLUTION: A tablet printing device includes: a conveyance part provided in a first region for conveying tablets by suction-holding the tablets in a suction hole; an ink jet head provided in the first region for executing printing for the tablets conveyed by the conveyance part; a heat generation source provided in a second region connected to the first region, which is provided side by side with the first region in a direction orthogonal to the conveyance direction of the tablets conveyed by the conveyance part; a cooling part for supplying gas whose temperature is lower than that of the second region, to the first region; and a moving mechanism provided in the second region for moving the ink jet head so as to change the interval between the face on a conveyance part side of the ink jet head and the face on an ink jet head side of the conveyance part. The cooling part further includes a separation member having an opening for the moving mechanism to be connected to the ink jet head, which is a wall provided so as to blow out gas avoiding the face on the conveyance part side of the ink jet head moved by the moving mechanism for separating the first region from the second region.SELECTED DRAWING: Figure 3

Description

[Technical field]

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

[0002] Currently, tablet printing devices that use inkjet heads to print various information such as identification information on tablets have been developed. Among these tablet printing devices, there are devices that use inkjet heads to print on tablets that are held by suction in suction holes. In such devices, a camera, detection sensor, control board that controls the inkjet head, etc., a blower used to hold the tablets by suction, a motor used to transport the tablets, etc. are all provided at the back of the area where printing is performed by the inkjet head.

[0003] The control board, blower, motor, etc. are heat sources, and the heated air is drawn into the suction hole by the suction used to hold the tablets. Because the inkjet head is located above the suction hole, the above-mentioned air flow raises the temperature near the inkjet head. When the temperature near the inkjet head rises, the viscosity of the ink inside the inkjet head decreases, making it impossible to eject a fixed amount of ink, or the area around the nozzle dries out, causing the ink to stick to the nozzle. This can lead to poor ejection and printing defects. Alternatively, the rise in temperature near the inkjet head can accelerate the deterioration of the ink inside the inkjet head. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-122401 Summary of the Invention [Problem to be solved by the invention]

[0005] The problem to be solved by the present invention is to provide a tablet printing apparatus and a tablet printing method capable of suppressing the occurrence of printing defects and the deterioration of ink.

Means for Solving the Problem

[0006] The tablet printing apparatus according to an embodiment of the present invention includes a conveying unit provided in a first region, for sucking and holding a tablet in a suction hole and conveying it; an inkjet head provided in the first region, for performing printing on the tablet conveyed by the conveying unit; a heat source provided in a second region so as to be aligned with the first region in a direction orthogonal to the conveying direction of the tablet conveyed by the conveying unit, and provided in the second region connected to the first region; a cooling unit for supplying a gas having a temperature lower than that of the second region to the first region from the first region side towards the second region ; a moving mechanism provided in the second region, for moving the inkjet head so as to change the distance between the surface of the inkjet head on the conveying unit side and the surface of the conveying unit on the inkjet head side; and the cooling unit is provided so as to blow out the gas while avoiding the surface of the inkjet head on the conveying unit side that moves by the moving mechanism, and further includes a partition member which is a wall for partitioning the first region and the second region, and has an opening for the moving mechanism to connect to the inkjet head.

[0007] The tablet printing method according to an embodiment of the present invention includes a conveying unit provided in a first region in a housing sucking and holding a tablet in a suction hole and conveying it; an inkjet head provided in the first region performing printing on the tablet conveyed by the conveying unit; Provided in the housing so as to be aligned with the first region in a direction orthogonal to the conveyance direction of the tablets conveyed by the conveyance unit, and in a state where a heat source exists in the second region connected to the first region, the cooling unit supplies a gas at a temperature lower than the temperature of the second region, from the first region side towards the second region avoiding the surface of the inkjet head on the conveyance unit side, and including supplying the gas, The first region and the second region are partitioned by a partition member having an opening for connecting an inkjet head provided in the first region and a moving mechanism provided in the second region for changing the distance between the surface of the inkjet head on the conveyance unit side and the surface of the conveyance unit on the inkjet head side.

Advantages of the Invention

[0008] According to the embodiment of the present invention, the occurrence of printing defects and the deterioration of ink can be suppressed.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Embodiments for Carrying Out the Invention

[0010] <Embodiment> An embodiment will be described with reference to the drawings.

[0011] (Configuration Example of Tablet Printing Device) A configuration example of the tablet printing device 1 according to the embodiment will be described with reference to FIGS. 1 and 2.

[0012] As shown in FIG. 1, the tablet printing device 1 according to the embodiment includes a supply device 10, a printing device 20, a recovery device 30, and a control device 40.

[0013] The supply device 10 has a hopper 11, an alignment feeder 12, and a delivery feeder 13. This supply device 10 is positioned on one end side of the printing device 20 and is configured to be able to supply tablets T, which are objects to be printed, to the printing device 20. The hopper 11 accommodates a large number of tablets T and sequentially supplies the accommodated tablets T to the alignment feeder 12. The alignment feeder 12 aligns the supplied tablets T in a row and conveys them in the conveyance direction A1 (clockwise direction) toward the delivery feeder 13. The delivery feeder 13 sequentially sucks and holds each of the tablets T arranged in a row on the alignment feeder 12 from above the tablets T, and conveys each of the held tablets T to the printing device 20 in a row and delivers them to the printing device 20. As the alignment feeder 12, for example, a belt conveyance mechanism or a vibration feeder is used. As the delivery feeder 13, for example, a belt conveyance mechanism is used. The belt conveyance mechanism of this delivery feeder 13 rotates in the conveyance direction A2 (counterclockwise direction). The supply device 10 is electrically connected to the control device 40, and its drive is controlled by the control device 40.

[0014] The printing device 20 includes a conveying unit 21, a detection unit 22, a first imaging unit 23, an inkjet head 24, a second imaging unit 25, a moving mechanism 26, a maintenance unit 27, and a drying unit 28.

[0015] Here, as shown in FIG. 2, the detection unit 22, the first imaging unit 23, the inkjet head 24, and the second imaging unit 25 are provided, for example, in pairs, but the number thereof is not particularly limited and is set according to the number of conveyance paths of the tablets T. Note that since the configurations of the respective detection units 22, the configurations of the respective first imaging units 23, the configurations of the respective inkjet heads 24, and the configurations of the respective second imaging units 25 are the same, only one of each will be described below.

[0016] Returning to FIG. 1, the conveying unit 21 includes a conveying belt 21a, a driving pulley 21b, a plurality of driven pulleys 21c, a motor 21d, a position detector 21e, and a suction chamber 21f. The conveying belt 21a is an endless belt and is spanned over the driving pulley 21b and each driven pulley 21c. The driving pulley 21b and each driven pulley 21c are rotatably provided on the apparatus main body (not shown), and the driving pulley 21b is connected to the motor 21d. The motor 21d is electrically connected to the control device 40, and its driving is controlled by the control device 40. The position detector 21e is a device such as an encoder and is attached to the motor 21d. This position detector 21e is electrically connected to the control device 40 and transmits a detection signal to the control device 40. The conveying unit 21 runs the conveying belt 21a together with each driven pulley 21c by the rotation of the driving pulley 21b by the motor 21d, and conveys the tablets T on the conveying belt 21a in the conveying direction A1 (clockwise direction).

[0017] As shown in FIG. 2, the conveying belt 21a is formed with a plurality of circular suction holes 21g. These suction holes 21g are through-holes for adsorbing the tablets T, respectively, and are arranged in two rows along the conveying direction A1 so as to form two parallel extending conveying paths. Each suction hole 21g is connected to the inside of the suction chamber 21f through a suction path (not shown) formed in the suction chamber 21f (see FIG. 1), and the suction chamber 21f enables the obtaining of a suction force. A blower is connected to the suction chamber 21f through a suction pipe (both not shown), and the inside of the suction chamber 21f is depressurized by the operation of the blower. The suction pipe is connected to the substantially center of the side surface of the suction chamber 21f (a surface parallel to the conveying direction A1). Further, the blower is electrically connected to the control device 40, and its drive is controlled by the control device 40. When the inside of the suction chamber 21f is depressurized, the tablets T placed on each suction hole 21g of the conveying belt 21a are sucked by the suction holes 21g and held on the conveying belt 21a.

[0018] The detection unit 22 is positioned on the downstream side in the conveying direction A1 from the position where the supply device 10 is provided, and is provided above the conveying path formed by the suction holes 21g. This detection unit 22 detects the arrival of the tablet T (the arrival of the tablet T) that has reached the detection position directly below the detection unit 22 by the transmission and reception of laser light, that is, the position of the tablet T in the X direction (see FIG. 2) on the conveying belt 21a. Further, the detection unit 22 detects the height of the tablet T on the conveying belt 21a. As the detection unit 22, for example, a displacement sensor is used. Further, as the displacement sensor, various laser sensors such as a reflection type laser sensor are used. The detection unit 22 is electrically connected to the control device 40 and transmits a detection signal to the control device 40.

[0019] The first imaging unit 23 is positioned downstream of the position where the detection unit 22 is provided in the conveyance direction A1, and is provided above the conveyance path formed by the suction holes 21g. Based on the position information in the X direction of the tablet T detected by the detection unit 22, the first imaging unit 23 performs imaging at the first imaging timing when the tablet T reaches the imaging position directly below the first imaging unit 23, acquires a first image including the upper surface of the tablet T, and transmits the acquired first image to the control device 40. The first image is used to detect the positions of the tablet T in the X direction, Y direction, and θ direction (see FIG. 2), and also to detect the presence or absence of damage or foreign matter attachment (e.g., cracks, chips, dirt, etc.) on the tablet T. As the first imaging unit 23, various cameras having imaging elements such as CCD (Charge Coupled Device) and CMOS (Complementary Metal Oxide Semiconductor) are used. The first imaging unit 23 is electrically connected to the control device 40, and its driving is controlled by the control device 40. In addition, illumination for imaging is provided as necessary.

[0020] Here, the positions of the tablet T in the X direction and Y direction are, for example, the positions in the XY coordinate system with respect to the center (reference position) of the imaging region of the first imaging unit 23. Also, the position in the θ direction is, for example, the position indicating the degree of rotation of the tablet T in the horizontal plane along the XY plane of the imaging region of the first imaging unit 23. This position in the θ direction is detected when the tablet T has a directional shape, such as when a score line is provided on the tablet T or when the tablet T is molded into an elliptical, oval, rectangular, or other shape. Note that the X direction and Y direction are positions in the horizontal direction.

[0021] The first imaging unit 23 further includes a cover 23a (see FIG. 2). The cover 23a corresponds to the first cover and is a member for preventing foreign matter from adhering to the light-receiving portion of the first imaging unit 23. The cover 23a is non-contact with the conveyance belt 21a and is provided so as to surround the first imaging unit 23. The lower end of the cover 23a is at the same height as the retracted position H3 of the inkjet head 24 described later (see FIG. 9). The lower end of the cover 23a does not necessarily have to be at the same height as the retracted position H3 of the inkjet head 24, and it may be at a height that does not contact the tablet T. The cover 23a is formed of a metal such as stainless steel, for example.

[0022] The inkjet head 24 is positioned downstream of the position where the first imaging unit 23 is provided in the conveyance direction A1 and is provided above the conveyance path formed by the suction holes 21g. The inkjet head 24 has a plurality (for example, several hundred to several thousand) of nozzles 24a (see FIG. 2), and is provided such that the direction in which the nozzles 24a are arranged in a row (nozzle row) is orthogonal (an example of intersection) to the conveyance direction A1 in the horizontal plane. The inkjet head 24 discharges ink individually from each nozzle 24a by the operation of a drive element for each nozzle 24a. As this inkjet head 24, various inkjet type printing heads having a drive element such as a piezoelectric element, a heating element, or a magnetostrictive element are used. The inkjet head 24 is electrically connected to the control device 40, and its drive is controlled by the control device 40.

[0023] The second imaging unit 25 is positioned downstream of the position where the inkjet head 24 is provided in the conveyance direction A1 and is provided above the conveyance path formed by the suction holes 21g. Based on the position information in the X direction of the tablet T detected by the detection unit 22, the second imaging unit 25 performs imaging at the second imaging timing when the tablet T reaches the imaging position directly below the second imaging unit 25, acquires a second image including the upper surface of the tablet T, and transmits the acquired second image to the control device 40. The second image is used to inspect the printed pattern printed on the tablet T. As the second imaging unit 25, similar to the aforementioned first imaging unit 23, for example, various cameras having imaging elements such as CCDs and CMOSs are used. The second imaging unit 25 is electrically connected to the control device 40, and its driving is controlled by the control device 40. Illumination for imaging is provided as necessary.

[0024] The second imaging unit 25 further includes a cover 25a (see FIG. 2). The cover 25a corresponds to the second cover and is a member for preventing foreign matter from adhering to the light-receiving portion of the second imaging unit 25. The cover 25a is non-contact with the conveyor belt 21a and is provided so as to surround the second imaging unit 25. The lower end of the cover 25a is at the same height as the retracted position H3 of the inkjet head 24 described later (see FIG. 9). The lower end of the cover 23a does not necessarily have to be at the same height as the retracted position H3 of the inkjet head 24, and it may be at a height that does not contact the tablet T. The cover 25a is formed of, for example, a metal such as stainless steel.

[0025] The moving mechanism 26 moves each inkjet head 24 in the vertical direction (the vertical direction in FIG. 1). As shown in FIG. 2, this moving mechanism 26 has, for example, an arm 26a and an arm moving mechanism 26b. The arm 26a is a holding portion that holds each inkjet head 24. For example, the arm 26a holds the ejection surface of each inkjet head 24 facing the conveyance surface of the conveyance belt 21a. The conveyance surface of the conveyance belt 21a is the surface on which the tablet T is placed on the conveyance belt 21a, and is the surface of the conveyance belt 21a on the side of the inkjet head 24. The ejection surface of the inkjet head 24 is the surface on which the nozzles 24a are formed in the inkjet head 24, and is the surface of the inkjet head 24 on the side of the conveyance belt 21a. The arm moving mechanism 26b is a mechanism that holds the arm 26a and moves it in the vertical direction. This arm moving mechanism 26b is provided at a position adjacent to the side surface of the suction chamber 21f (a surface parallel to the conveyance direction A1). As the arm moving mechanism 26b, for example, a linear guide mechanism is used. The arm moving mechanism 26b is electrically connected to the control device 40, and its drive is controlled by the control device 40. Such a moving mechanism 26 can change the distance (separation distance) between the conveyance surface of the conveyance belt 21a and the ejection surface of each inkjet head 24 by raising and lowering the arm 26a, that is, each inkjet head 24, by the arm moving mechanism 26b.

[0026] In this embodiment, the maximum upward position of the inkjet head 24 is the maintenance position H2, which will be described later. However, the maximum upward position of the inkjet head 24 is not limited to this. The maximum upward position of the inkjet head 24 may be a position higher than the maintenance position H2. That is, the maximum upward position may be, for example, a height such that the vicinity of the nozzles of the inkjet head 24 does not dry due to the cooling unit 61 described later. However, the lower the maximum upward position of the inkjet head 24, the lower the height of the ceiling of the cover 53 described later can be. The lower the height of the ceiling of the cover 53, the smaller the volume of the space covered by the cover 53. Therefore, the cooling efficiency of the cooling unit 61 described later can be improved.

[0027] The maintenance unit 27 performs maintenance operations on each inkjet head 24. Examples of maintenance operations include a wiping operation and an ink receiving operation. As shown in FIG. 2, the maintenance unit 27 includes, for example, a wiping unit 27a and a drip tray 27b. The wiping unit 27a is a cleaning unit that cleans the ejection surface of each inkjet head 24 by reciprocating movement of the maintenance unit 27 in the Y direction (see FIG. 2). The drip tray 27b is a receiving member that receives droplets ejected from each inkjet head 24. Such a maintenance unit 27 is provided at a position adjacent to the side surface of the suction chamber 21f (a surface parallel to the conveyance direction A1), and is configured to be movable by a movement mechanism (for example, a linear guide mechanism) not shown between the conveyance surface of the conveyance belt 21a and the ejection surface of each inkjet head 24. During maintenance execution, the distance between the conveyance surface of the conveyance belt 21a and the ejection surface of each inkjet head 24 is widened by the movement mechanism 26 by a distance that allows the maintenance unit 27 to move between these surfaces to perform maintenance operations.

[0028] The drying unit 28 is disposed at a position facing the conveyance belt 21a, and is provided, for example, below the conveyance unit 21. The drying unit 28 dries the ink applied to each tablet T on the conveyance belt 21a. As the drying unit 28, various dryers such as a blower that dries with a gas such as air, a heater that dries with radiant heat, or a blower that dries with warm air or hot air using a combination of a gas and a heater are used. The drying unit 28 is electrically connected to the control device 40, and its drive is controlled by the control device 40.

[0029] The recovery device 30 is positioned downstream of the position where the drying unit 28 is provided in the conveyance direction A1, and is provided below the conveyance unit 21. This recovery device 30 has a reusable product recovery unit 31, a defective product recovery unit 32, and a non-defective product recovery unit 33. The recovery device 30 recovers the reusable tablets T by the reusable product recovery unit 31, recovers the defective tablets T by the defective product recovery unit 32, and recovers the non-defective tablets T by the non-defective product recovery unit 33. For example, reusable products are reusable tablets, which are non-printed tablets without damage and foreign matter attachment. Also, defective products are non-printed tablets with foreign matter attachment, printed non-conforming tablets (printed tablets) without damage and foreign matter attachment, etc., and non-defective products are printed conforming tablets (printed tablets) without damage and foreign matter attachment. Note that the arrangement order in the conveyance direction A1 in the reusable product recovery unit 31, the defective product recovery unit 32, and the non-defective product recovery unit 33 is not limited to the arrangement order shown in FIG. 1, and may be changed as appropriate. The recovery device 30 is electrically connected to the control device 40, and its drive is controlled by the control device 40.

[0030] The reusable product recovery unit 31 has an injection nozzle 31a and a recovery box 31b. Also, the defective product recovery unit 32 has an injection nozzle 32a and a recovery box 32b. The non-defective product recovery unit 33 has an injection nozzle 33a and a recovery box 33b. These injection nozzles 31a, 32a, 33a basically have the same structure, and each of the recovery boxes 31b, 32b, 33b also basically has the same structure. Therefore, the injection nozzle 31a and the recovery box 31b will be described as representatives.

[0031] The injection nozzle 31a and the collection box 31b are provided at positions facing each other with the conveyance path along which the suction holes 21g of the conveyance belt 21a are arranged therebetween. The injection nozzle 31a is disposed within the suction chamber 21f, and for example, injects a gas (such as air) toward the conveyance belt 21a to drop the tablets T from the conveyance belt 21a. At this time, the gas injected from the injection nozzle 31a passes through the suction holes 21g of the conveyance belt 21a and hits the tablets T. The injection nozzle 31a is electrically connected to the control device 40, and its drive is controlled by the control device 40. The collection box 31b is provided directly below the injection nozzle 31a and below the conveyance unit 21. This collection box 31b receives and accommodates the tablets T dropped from the conveyance belt 21a by the gas injected from the injection nozzle 31a.

[0032] Here, the tablets T that have passed through the reused product collection unit 31 and the defective product collection unit 32 are conveyed as the conveyance belt 21a moves and reach a position near the end on the side of each driven pulley 21c in the conveyance belt 21a. At this position, the suction action no longer acts on the tablets T, but a gas is blown onto the tablets T from above by the injection nozzle 33a, and the tablets T fall from the conveyance belt 21a. Therefore, by providing the injection nozzle 33a, the tablets T can be surely dropped from the conveyance belt 21a. The collection box 33b receives and accommodates the tablets T dropped from the conveyance belt 21a by the gas injected from the injection nozzle 33a.

[0033] The control device 40 controls each part of the tablet printing device 1, such as the supply device 10, the printing device 20, the collection device 30, etc., based on various information and various programs. Further, the control device 40 receives detection information (such as detection signals) respectively transmitted from the position detector 21e of the conveyance unit 21 and the detection unit 22, and also receives image information etc. transmitted from the first imaging unit 23 and the second imaging unit 25. The control device 40 is realized by, for example, an electronic circuit such as an integrated circuit or a computer.

[0034] (Cooling function of the tablet printing device) Next, the cooling function of the tablet printing apparatus 1 will be described with reference to FIGS. 2 to 7.

[0035] As shown in FIGS. 2 to 4, the tablet printing apparatus 1 has a housing 51. This housing 51 houses each part included in the tablet printing apparatus 1. Each part includes a supply device 10, a printing device 20, a recovery device 30, and a control device 40. In the example of FIG. 3, a cooling unit 61, a heat source 62, a transport unit 21, each inkjet head 24, a moving mechanism 26, and a maintenance unit 27 are shown.

[0036] The housing 51 has a door 52, a door 55, and a cover 53. The doors 52 and 55 are attached to the housing 51 so as to be openable and closable. An opening 52a is formed in the door 52. This opening 52a is sized to fit the exterior of the cooling unit 61, and further, when the door 52 is closed, the end of the cooling unit 61 on the door 52 side is inserted into the opening 52a. A gap member such as a packing may be provided in this opening 52a. The housing 51 has a holding portion 51a above the inkjet head 24 and above the heat source 62. The holding portion 51a is, for example, a planar plate that covers the upper sides of the inkjet head 24, the first imaging unit 23, and the second imaging unit 25. Above the holding portion 51a, an input device 40a, an output device 40b, etc., which will be described later, are housed. Below the holding portion 51a, a detection unit 22, a first imaging unit 23, a second imaging unit 25, etc., are housed. Also, a partition member 54 is provided between the transport unit 21 and the heat source 62 inside the housing 51.

[0037] The partition member 54 is a wall separating the first region R1 from the second region R2 and prevents heat from the heat source 62 from flowing into the first region R1. The partition member 54 is formed of a metal plate, such as stainless steel. The length of the partition member 54 in the X direction is the same as the length of the transport unit 21 in the X direction. The upper end of the partition member 54 is connected to the ceiling of the housing 51, but is not necessarily connected to the ceiling of the housing 51. A gap may be provided between the upper end of the partition member 54 and the ceiling of the housing 51. A cable connects the first imaging unit 23 or the second imaging unit 25 to the control board. The partition member 54 has a hole (not shown) through which the cable can pass. As shown in FIGS. 4 and 5, the partition member 54 has an opening 54a. The opening 54a is an opening through which the movement mechanism 26 connects to the inkjet head 24. The opening 54a also serves as an opening through which the maintenance unit 27 moves between the first area R1 and the second area R2.

[0038] In this embodiment, the opening 54a is a cutout. The outer shape of the opening 54a is T-shaped. For example, a portion of the partition member 54, which is rectangular or quadrangular, is cut out in a T-shape, thereby forming the T-shaped opening 54a in that portion of the partition member 54. Specifically, the opening 54a is formed by cutting the partition member 54 downward in the Z direction from its upper end. The length of the opening 54a in the X direction at the upper end of the partition member 54 is the same as the length of the door 52. The length of the portion of the opening 54a that protrudes downward in the X direction is the same as the length of the cover 53 in the X direction. The opening 54a is provided at a position where the maintenance unit 27 and the partition member 54 intersect. In other words, the upper end of the partition member 54 at the position where the protruding portion of the opening 54a is provided is provided at a height that allows the maintenance unit 27 to move between the first area R1 and the second area R2. The opening 54a is a T-shaped notch to avoid interference between the partition member 54 and the holding portion 51a. In cases where there is no holding portion 51a, for example, the opening 54a may be a notch of a shape other than T, or may be a hole of a shape such as rectangular, square, or circular.

[0039] As shown in FIG. 5, the partition member 54 may be formed from a single plate, or as shown in FIG. 6, may be formed by combining a plurality of plates 54b. In this case, there may be a plate 54b that closes the upper part of the holding portion 51a. Further, as shown in FIG. 7, the partition member 54 may be formed from a plurality of plates 54b and a frame 54c that can be attached to the housing 51. Note that instead of the frame 54c, a plurality of plates 54b may be attached to columns, beams, etc. of the housing 51.

[0040] Returning to FIGS. 2 and 3, the cover 53 is a cover member that closes the space above the conveyance unit 21 from the door 52 side (front side). At least each inkjet head 24 exists in the space surrounded by the cover 53. Further, the cover 53 is attached to the partition member 54 so as to cover a part of the opening 54a of the partition member 54, and is a cover that closes the space above the conveyance unit 21. That is, the space surrounded by the cover 53 communicates with the opening 54a of the partition member 54. In the present embodiment, since the upper part of the opening 54a is partitioned by the holding portion 51a, it cannot be covered by the cover 53. However, if the cover 53 can cover all of the opening 54a, it may be covered. The main point is that the cover 53 should be able to cover the range in which the gas in the second region R2 flows toward the inkjet head 24.

[0041] The cover 53 has, for example, a main body 53b and a door portion 53c. The main body 53b is a member that covers the space above the conveying unit 21 and has a U-shaped outer profile when viewed from the front side with the U-shaped opening facing downward. The main body 53b is connected to the partition member 54 so as to cover a part or all of the opening 54a of the partition member 54 with the U-shaped opening facing downward. Therefore, the main body 53b has two side surfaces orthogonal to the conveying direction A1 and a ceiling connecting the two side surfaces. The ceiling of the main body 53b is higher than the upper part of the inkjet head 24 at the maximum ascending position. Also, the ceiling of the main body 53b is at a height within the range of the lifting stroke of the inkjet head 24 and higher than the upper end of the inkjet head 24 at the maximum ascending position. The main body 53b is provided so as to just fill the space between the cover 23a and the cover 25a.

[0042] The door portion 53c is a door that can be opened and closed with respect to the main body 53b. The door portion 53c has, for example, a box shape with one of the four side surfaces missing. The door portion 53c is attached to the end portion on the side opposite to the partition member 54 side of the main body 53b via a hinge (not shown) with the missing side surface facing the inkjet head 24. Also, the door portion 53c is detachably provided on the cover 25a. Therefore, in the present embodiment, the cover 53 corresponds to a third cover that closes the space above the conveying unit 21 between the cover 23a and the cover 25a.

[0043] The door portion 53c is attached to the cover 25a while the tablet printing apparatus 1 is operating. Also, when attaching and detaching the inkjet head 24, the door portion 53c is removed from the cover 25a and moved to the cover 23a side via a hinge (not shown). Therefore, the inkjet head 24 can be attached and detached from the front side. Thus, the attachment and detachment of the inkjet head 24 can be easily performed.

[0044] On the surface of the cover 53 on the door 52 side (the surface parallel to the conveyance direction A1), a ventilation part 53a is formed. The upper part of the ventilation part 53a is at the same height as the ceiling of the main body 53b or several cm (centimeters) lower. Also, the ceiling of the main body 53b is at a height higher by the height within the lifting stroke range of the inkjet head 24 than the upper end of the inkjet head 24 at the maximum rising position. As this ventilation part 53a, for example, a mesh member such as a wire mesh or a punching member such as a punching plate is used. The ventilation part 53a is for supplying the outside air taken in by the cooling part 61 from the ventilation part 53a into the cover 53. The cooling part 61 is provided on the surface of the cover 53 on the door 52 side so as to block the ventilation part 53a. Also, it is preferable that the lower end of the ventilation part 53a is higher in the height direction than the upper part of the inkjet head 24 at the maximum rising position. When the lower end of the ventilation part 53a is higher than the upper part of the inkjet head 24, the flow of the cooling gas is not obstructed by the inkjet head 24. Therefore, the cooling gas from the cooling part 61 easily flows into the second region R2. In this case, needless to say, the upper end of the ventilation part 53a is provided above the lower end of the ventilation part 53a.

[0045] In the housing 51, there exist a first region R1 and a second region R2 connected (communicating) to the first region R1. In the first region R1, a conveyance part 21, each inkjet head 24, etc. are provided, and in the second region R2, a heat source 62 is provided. The moving mechanism 26 exists across the first region R1 and the second region R2, the maintenance part 27 has a standby position in the second region R2, and the maintenance position is in the first region R1. The maintenance position of the maintenance part 27 is a position where maintenance (such as purging, dummy ejection, wiping, etc.) of the inkjet head 24 is performed, and it is a position below the inkjet head 24. The standby position of the maintenance part 27 is the position of the maintenance part 27 when maintenance of the inkjet head 24 is not being performed, and it is a predetermined position in the second region R2 as shown in FIG. 3. The maintenance part 27 moves between the maintenance position and the standby position, that is, it moves in the left - right direction in FIG. 3.

[0046] Here, the first region R1 is a region of the housing 51 closer to the door 52 than the partition member 54. The second region R2 is a region of the housing 51 closer to the heat source 62 than the partition member 54.

[0047] Each inkjet head 24 is moved in a lifting direction (up and down direction in FIG. 3) by the movement mechanism 26, and the movement range Ha of the ejection surfaces in the lifting direction is the range between a normal position H1 where each inkjet head 24 is normally located and a maintenance position H2 where the maintenance unit 27 performs maintenance work on each inkjet head 24. The maintenance position H2 is a position where the maintenance unit 27 moves between the conveyance surface of the conveyor belt 21a and the ejection surfaces of each inkjet head 24 to perform maintenance work.

[0048] The cooling unit 61 takes in outside air and sends it into the cover 53. The cooling unit 61 may be, for example, a cooling fan that creates an air flow, but is not limited to this. The cooling unit 61 may be any device that can supply gas at least to the first region R1 at a temperature lower than that of the second region R2, and may be, for example, a supply unit that supplies compressed gas via a tube or the like. The gas may be, for example, air or nitrogen.

[0049] The cooling unit 61 is also provided to face the heat source 62 with the inkjet heads 24 therebetween in a direction intersecting the X direction, which is the conveying direction A1 of the tablets T (for example, the Y direction, which is a direction perpendicular to the X direction). Specifically, the cooling unit 61 is provided on the end side in the direction (Y direction) in which the inkjet heads 24 are lined up. This is to ensure that the gas supplied by the cooling unit 61 hits all of the inkjet heads 24.

[0050] Further, the cooling unit 61 blows and supplies gas along a direction (for example, the Y direction which is an orthogonal direction orthogonal to the conveyance direction A1 of the tablet T) intersecting in the horizontal plane. Since the gas is supplied toward the second region R2 on the heat source 62 side, it is possible to prevent the inflow of air from the second region R2 on the heat source 62 side into the suction hole 21g. If the inflow rate of the air flowing from the second region R2 into the suction hole 21g decreases due to the gas supplied from the cooling unit 61, the temperature of the air sucked into the suction hole 21g will drop, and as a result, the temperature of the first region R1 will also drop. Note that as the gas supply direction, for example, by providing the cooling unit 61 above the inkjet head 24, the gas may be supplied from above the inkjet head 24 downward, and as long as the temperature of the air flowing into the suction hole 21g can be lowered, the gas supply direction is not particularly limited.

[0051] Further, the lower end of the cooling unit 61 is always higher than the ejection surface of each inkjet head 24 that moves in the lifting direction, that is, above the upper limit of the movement range Ha in the lifting direction of the ejection surface of each inkjet head 24. That is, the cooling unit 61 is provided so as to blow out gas while avoiding the ejection surface of the inkjet head 24 that moves by the movement mechanism 26.

[0052] Such a cooling unit 61 is electrically connected to the control device 40, and its drive is controlled by the control device 40. For example, the cooling unit 61 may be constantly driven in a state where the device power is turned on, or may be driven for a predetermined time or stopped for a predetermined time. Further, since the diffusion of heat by the heat source 62 is weak for a predetermined time from the start of tablet printing (for example, the predetermined time when a predetermined number of tablets T are printed), the cooling unit 61 may be driven after the elapse of the predetermined time. In addition, a cooling unit 161 is provided on the second region R2 side of the housing 51.

[0053] The cooling unit 161 takes in the air within the second region R2 and discharges it to the outside of the apparatus. The cooling unit 161 is provided, for example, at a portion of the housing 51 that separates the outside of the apparatus from the second region R2. As the cooling unit 161, for example, a cooling fan is used. However, the cooling unit 161 is not limited thereto. The cooling unit 161 may also be a blower, a pump, or the like. When the cooling unit 161 is a blower or a pump, the cooling unit 161 is provided outside the apparatus. And the cooling unit 161 is connected via a pipe to a portion of the housing 51 that is in contact with the second region R2.

[0054] The heat source 62 is a source that generates heat. For example, the heat source 62 is a heat source related to one or both of the conveying operation of the conveying unit 21 and the printing operation of the inkjet head 24. Examples of such a heat source 62 include a control board such as the control device 40, a blower used for sucking and holding the tablet T, and a motor used for conveying the tablet T.

[0055] (Configuration example of the control device) Next, a configuration example of the control device 40 will be described with reference to FIG. 8.

[0056] As shown in FIG. 8, the control device 40 includes an image processing unit 41, a storage unit 42, and a control unit 43. An input device 40a and an output device 40b are connected to this control device 40. The input device 40a is realized, for example, by a switch, a touch panel, a keyboard, a mouse, or the like. Also, the output device 40b is realized, for example, by a display, a lamp, a meter, or the like.

[0057] The image processing unit 41 captures the first image captured by the first imaging unit 23 and the second image captured by the second imaging unit 25, and processes the images using known image processing techniques. For example, the image processing unit 41 processes the first image obtained from the first imaging unit 23 to acquire the presence or absence of damage or foreign matter attachment on the tablet T, and further acquires the positions of the tablet T in the X direction, Y direction, and θ direction. In addition, the image processing unit 41 processes the second image obtained from the second imaging unit 25 to acquire the printing position, shape, and size of the printing pattern (e.g., characters or marks) printed on the tablet T. The image processing unit 41 transmits the acquired information on the presence or absence of damage or foreign matter attachment on the tablet T, the acquired position information of each tablet T in the X direction, Y direction, and θ direction, and further the printing position information, shape information, and size information of the printing pattern on each tablet T to the control unit 43.

[0058] The storage unit 42 stores processing information, various programs, and the like. For example, it is realized by a semiconductor memory element such as a RAM (Random Access Memory) or a flash memory, or a storage device such as a hard disk or an optical disk. The storage unit 42 stores printing data related to printing, moving speed data of the conveyor belt 21a, and the like. The printing data includes information on printing patterns such as characters and marks.

[0059] The control unit 43 is a computer such as a CPU (Central Processing Unit), MCU (Micro Control Unit), or MPU (Micro Processing Unit), and controls each unit. For example, the control unit 43 controls the supply device 10, the printing device 20, the recovery device 30, the image processing unit 41, the storage unit 42, etc. based on various information and various programs stored in the storage unit 42. In addition, the control unit 43 receives detection signals transmitted from the position detector 21e of the transport unit 21 and the detection unit 22, respectively. Note that the control unit 43 is realized by, for example, one or both of hardware and software.

[0060] (Movement of the inkjet head by maintenance) For example, when performing maintenance work, the control unit 43 controls the movement mechanism 26 to move the ejection surface of each inkjet head 24 from the normal position H1 to the maintenance position H2. After the ejection surface of each inkjet head 24 has moved to the maintenance position H2, the control unit 43 then moves the maintenance unit 27 to the maintenance position in the Y direction to perform maintenance on the ejection surface of each inkjet head 24. Furthermore, as necessary, the control unit 43 moves the maintenance unit 27 to a position where the tray 27b of the maintenance unit 27 faces the ejection surface of each inkjet head 24, causes each inkjet head 24 to eject ink continuously, and then returns the maintenance unit 27 to its original position.

[0061] Here, the normal position H1, the maintenance position H2, etc. are usually set in advance and stored, for example, in the storage unit 42. However, the normal position H1, the maintenance position H2, etc. may be changed according to predetermined conditions, or may be changed according to an input operation by the user to the input device 40a.

[0062] (Inkjet head movement due to abnormal tablet height) Also, during tablet printing execution, the control unit 43 determines whether the height of the tablet T on the conveyor belt 21a is abnormal based on the height information regarding the height of the tablet T detected by the detection unit 22. For example, when the height of the tablet T exceeds a predetermined threshold value, the control unit 43 determines that the height of the tablet T on the conveyor belt 21a is abnormal. As shown in FIG. 9, a tablet in an abnormal height state (hereinafter also referred to as a "height-abnormal tablet") T is, for example, a tablet in an upright posture. The tablet T in an upright posture is in a state where the posture of the tablet T is perpendicular to or inclined with respect to the conveying surface of the conveyor belt 21a. If it is conveyed by the conveyor belt 21a directly below the inkjet head 24 in that posture, it collides with the inkjet head 24 whose ejection surface is located at a predetermined normal position H1. The tablet T may be held on the conveyor belt 21a in an upright posture by the suction action of the suction hole 21g. In particular, when the held surface of the tablet T has an R shape, a point other than the central portion of the tablet T may become a region to be sucked, and it may be held in an upright posture.

[0063] Further, the control unit 43 changes the conveying speed at which the conveyor belt 21a conveys the tablet T and changes the distance between the conveying surface of the conveyor belt 21a and the ejection surface of the inkjet head 24 based on whether the height of the tablet T on the conveyor belt 21a is abnormal. For example, when the height of the tablet T on the conveyor belt 21a is abnormal, the control unit 43 controls the conveying unit 21 to lower the conveying speed of the conveyor belt 21a and controls the moving mechanism 26 to widen the distance between the conveying surface of the conveyor belt 21a and the ejection surface of the inkjet head 24. Thereafter, when the tablet T in an abnormal height state passes directly below the inkjet head 24, the control unit 43 controls the moving mechanism 26 to return the inkjet head 24 to the normal position H1 and controls the conveying unit 21 to return the conveying speed of the conveyor belt 21a to its original value.

[0064] More specifically, as shown in FIG. 9, the control unit 43 controls the movement mechanism 26 so that the inkjet head 24 moves upward with respect to the tablet T in an abnormal height state, and the ejection surface of the inkjet head 24 moves from a predetermined normal position H1 to a predetermined retracted position H3. As a result, the distance between the conveyance surface of the conveyance belt 21a and the ejection surface of the inkjet head 24 widens. Even if the tablet T in an abnormal height state reaches directly below the inkjet head 24 where the ejection surface is located at the predetermined retracted position H3 by the conveyance belt 21a in that state, it passes directly below the inkjet head 24 without colliding with the inkjet head 24. Thereafter, at the timing when the tablet T in an abnormal height state has passed directly below the inkjet head 24, the control unit 43 controls the movement mechanism 26 so that the inkjet head 24 moves downward and the ejection surface of the inkjet head 24 moves from the predetermined retracted position H3 to the predetermined normal position H1. As a result, the distance between the conveyance surface of the conveyance belt 21a and the ejection surface of the inkjet head 24 returns to its original state.

[0065] Here, usually, a predetermined threshold value, a predetermined normal position H1, a predetermined retracted position H3, etc. are set in advance, for example, stored in the storage unit 42. The normal position H1 is the lower limit value of the movement range Ha of the ejection surface of the inkjet head 24, and the predetermined retracted position H3 is a position lower than the maintenance position H2 which is the upper limit value of the movement range Ha. However, the predetermined threshold value, the predetermined normal position H1, the predetermined retracted position H3, etc. may be changed according to predetermined conditions, or may be changed according to a user's input operation to the input device 40a. The predetermined threshold value is set, for example, to a value of the thickness of the tablet T + 1 mm. The distance between the printing surface of the tablet T and the ejection surface of the inkjet head 24 is usually about 1 mm, and the thickness of the tablet T is about 2 to 8 mm. Considering the case where the tablet T is 3 mm, when the detected height of the tablet T exceeds 4 mm, it exceeds the threshold value, and it is determined that the tablet T has an abnormal height, and the collision of the tablet T with the inkjet head 24 can be prevented. The predetermined normal position H1 is, for example, a position (for example, a height position 1 mm away from the printing surface of the tablet T) where the inkjet head 24 can normally print on the tablet T on the conveying belt 21a without colliding with the tablet T in a lying state (normal posture) on the conveying belt 21a, and is set experimentally or theoretically. Also, the predetermined retracted position H3 is a position where the inkjet head 24 does not contact the tablet T in an abnormal height state on the conveying belt 21a (for example, a height position separated from the conveying belt 21a by more than the major diameter of the tablet T). Regarding both positions, a margin is taken as appropriate.

[0066] Further, based on the detection information transmitted from the detection unit 22, that is, the timing when the tablet T on the conveyor belt 21a is detected, the control unit 43 acquires the position of the tablet T in the X direction on the conveyor belt 21a, and based on the position information indicating the position of the tablet T in the X direction, sets the first imaging timing of the first imaging unit 23, the printing start timing of the inkjet head 24, and the second imaging timing of the second imaging unit 25, and generates timing information indicating those timings and stores it in the storage unit 42. The printing start timing is the timing to start printing on the tablet T that has reached the printing position directly below the inkjet head 24. Note that the control unit 43 can acquire information such as the movement amount (rotation amount) and speed of the conveyor belt 21a based on the detection information transmitted from the position detector 21e.

[0067] Also, based on the presence / absence information of damage or foreign matter attachment of the tablet T (this information is information based on the first image) transmitted from the image processing unit 41, the control unit 43 sets the printability for the tablet T for which the presence / absence information has been obtained as printability information. Then, the control unit 43 sets printing conditions as printing condition information for the tablet T for which printing is enabled. At this time, the control unit 43 sets printing conditions for the tablet T for which the position information has been obtained based on the position information of the tablet T in the X direction, Y direction, and θ direction transmitted from the image processing unit 41. For example, based on the position information of the tablet T in the Y direction and the print data, the control unit 43 determines the range of nozzles 24a used for printing the target tablet T in the inkjet head 24, that is, the used nozzle range, and sets printing conditions including the used nozzle range and the printing start timing. When the tablet T has a shape with a direction, the control unit 43 sets printing conditions corresponding to the position of the tablet T in the θ direction based on the position information of the tablet T in the θ direction. As an example, the control unit 43 registers 180 print patterns in which the orientation of the print pattern is rotated by 1 degree in the range from 0 degrees to 179 degrees in the storage unit 42, and selects a print pattern with an angle that matches the position of the tablet T in the θ direction from those print patterns to set the printing conditions.

[0068] Further, the control unit 43 determines whether the printed pattern is printed at a predetermined position on the tablet T in a predetermined shape and a predetermined size, that is, whether the printed pattern is normally printed on the tablet T, based on the printing position information, the shape information, and the size information of the printed pattern printed on the tablet T (these information are the information based on the second image) transmitted from the image processing unit 41, and sets the printing quality information of the tablet T (printing state inspection). For example, in determining the shape and size of the printed pattern, the control unit 43 registers the printed pattern for inspection in the storage unit 42, and compares the printed pattern for inspection with the printed pattern on the actual tablet T after printing (the printed pattern printed on the tablet T).

[0069] In addition, the control unit 43 appropriately stores various information (for example, information on the presence or absence of damage or foreign matter attachment to the tablet T, position information, height information of the tablet T, timing information, printability information, printing condition information, printing quality information, etc.) in the storage unit 42. When the target tablet T is collected by the collection device 30, for example, when a predetermined time (for example, several seconds) has elapsed after dropping from the downstream end of the transport direction A1 in the transport unit 21, the control unit 43 deletes the various information from the storage unit 42. However, when such information is required in a subsequent process or the like, it is also possible to leave the various information for each tablet T without deleting it, or to store it in a storage medium outside the device. When storing the various information for each tablet T, this information may be stored in association with the manufacturing date and time, lot number, etc., so that the cause can be traced back in case of defective products after shipment of the printed tablet T.

[0070] (Printing process) Next, the printing process performed by the aforementioned tablet printing device 1 will be described with reference to FIG. 10. This printing process includes an inspection process. Various information such as data required for printing and data required for retracting the inkjet head 24 are stored in the storage unit 42 in advance.

[0071] As shown in FIG. 10, in step S1, when a large number of tablets T to be printed are loaded into the hopper 11 of the supply device 10, the tablets T start to be sequentially supplied from the hopper 11 to the alignment feeder 12 and are aligned and moved in a row by the alignment feeder 12. The tablets T moving in this row are sequentially supplied to the conveyor belt 21a of the printing device 20 by the delivery feeder 13. The conveyor belt 21a rotates in the conveying direction A1 by the rotation of the driving pulley 21b and each driven pulley 21c by the motor 21d. Therefore, the tablets T supplied onto the conveyor belt 21a are arranged in a row on the conveyor belt 21a and conveyed at a predetermined conveying speed.

[0072] In step S2, the tablets T on the conveyor belt 21a are detected by the detection unit 22. Specifically, the tablets T on the conveyor belt 21a are detected by the detection unit 22 at the timing when the tablets T on the conveyor belt 21a reach the detection position (for example, the irradiation position of the laser beam) directly below the detection unit 22. Based on the timing when the tablets T are detected, the position of the tablets T in the X direction on the conveyor belt 21a is recognized by the control unit 43. Then, position information indicating the position of the tablets T in the X direction is generated by the control unit 43 and stored in the storage unit 42. Also, the height of the tablets T on the conveyor belt 21a is detected by the detection unit 22, the height information regarding the height of the tablets T is recognized by the control unit 43, and the height information of the tablets T is stored in the storage unit 42.

[0073] In step S3, based on the height information, it is determined whether the height of the tablets T on the conveyor belt 21a is abnormal. For example, it is determined whether the height of the tablets T on the conveyor belt 21a exceeds a predetermined threshold value. When it is determined that the height of the tablets T on the conveyor belt 21a exceeds the predetermined threshold value, it is determined that the height of the tablets T on the conveyor belt 21a is abnormal (Yes in step S3), and the process proceeds to step S11. On the other hand, when it is determined that the height of the tablets T on the conveyor belt 21a does not exceed the predetermined threshold value, it is determined that the height of the tablets T on the conveyor belt 21a is normal (No in step S3), and the process proceeds to step S4.

[0074] In step S4, the tablet T on the conveyor belt 21a is imaged by the first imaging unit 23. Specifically, the tablet T on the conveyor belt 21a is imaged by the first imaging unit 23 at the first imaging timing when it reaches the imaging position directly below the first imaging unit 23, and the first image obtained by the imaging by the first imaging unit 23 is transmitted to the control device 40. Based on this first image, information on the presence or absence of damage or foreign matter attachment to the tablet T, and position information of the tablet T in the X direction, Y direction, and θ direction are generated by the image processing unit 41 and stored in the storage unit 42.

[0075] In step S5, based on the information on the presence or absence of damage or foreign matter attachment to the tablet T, the control unit 43 determines whether printing on the target tablet T is possible. If it is determined that printing on the target tablet T is possible (Yes in step S5), the process proceeds to step S6. Note that based on information such as the position information of the tablet T in the X direction, Y direction, and θ direction and the printing pattern, printing conditions including the nozzle use range and printing start timing for the tablet T set to be printable (printable tablet T) are set in the storage unit 42. Based on the aforementioned printing start timing (the timing to start printing on the tablet T), the ejection timing (the timing to eject ink onto the tablet T) for the tablet T is determined. On the other hand, if it is determined that printing on the target tablet T is not possible (No in step S5), the process proceeds to step S9, and operations related to printing and inspection on the target tablet T are restricted. Note that the printability information of the tablet T is appropriately stored in the storage unit 42. Note that the "restriction" of operations related to printing and inspection means at least not performing processes related to printing and inspection on the target tablet T.

[0076] In step S6, printing is performed by the inkjet head 24 based on the above printing conditions. That is, the inkjet head 24 is controlled by the control unit 43 to print a predetermined printing pattern on the printable tablet T on the conveyor belt 21a. Specifically, the printable tablet T on the conveyor belt 21a that has passed below the first imaging unit 23 is printed by the inkjet head 24 based on the above printing conditions at the printing start timing when it reaches the printing position directly below the inkjet head 24. In the inkjet head 24, ink is appropriately ejected from each nozzle 24a, and a printing pattern (for example, numbers, alphabets, hiragana, symbols, figures) is printed on the printing surface, which is the upper surface of the tablet T.

[0077] In step S7, the printed tablet T on the conveyor belt 21a is imaged by the second imaging unit 25. Specifically, the printed tablet T on the conveyor belt 21a is imaged by the second imaging unit 25 at the second imaging timing when it reaches the imaging position directly below the second imaging unit 25, and the second image obtained by the imaging by the second imaging unit 25 is transmitted to the control device 40. This second image is processed by the image processing unit 41 of the control device 40. Specifically, information regarding the printed printing pattern on the tablet T, that is, the printing position, shape, and size of the printed printing pattern are acquired by the image processing unit 41. The second image transmitted from the second imaging unit 25 is processed by the image processing unit 41, inspection information indicating the printing position, shape, and size of the printed printing pattern on the tablet T is generated, and is stored in the storage unit 42.

[0078] In step S8, a print status inspection is performed by the control unit 43 based on the above-mentioned inspection information. More specifically, based on the inspection information related to the printing position, shape, and size stored in the memory unit 42, the control unit 43 determines whether the printing pattern has been printed correctly on the tablet T, and print pass / fail information indicating whether the printing on the tablet T is pass / fail is generated and stored in the memory unit 42. For example, in the print status inspection, the printing pattern used for printing is stored in the memory unit 42 as a test printing pattern, and pass / fail information related to the predetermined printing position, shape, and size of the test printing pattern is compared with inspection information related to the printing position, shape, and size of the actually printed printing pattern stored in the memory unit 42, and it is determined whether the printing pattern has been printed correctly on the tablet T (pass or fail).

[0079] In step S9, the tablets T on the conveyor belt 21a are collected by the collection device 30. The ink applied to the tablets T dries naturally during transport and is dried by the drying section 28. In detail, when the reused tablets T reach the reused product collection section 31 as the conveyor belt 21a moves, gas is sprayed onto the tablets T from above by the spray nozzle 31a, and the tablets T fall from the conveyor belt 21a and are collected in the collection box 31b. Similarly, when the defective tablets T reach the defective product collection section 32 as the conveyor belt 21a moves, gas is sprayed onto the tablets T from above by the spray nozzle 32a, and the tablets T fall from the conveyor belt 21a and are collected in the collection box 32b. Furthermore, when a non-defective tablet T reaches a position near the end of the conveyor belt 21a on the side of each driven pulley 21c, the suction action on the tablet T ceases, and gas is blown onto the tablet T from above by the injection nozzle 33a, causing the tablet T to drop from the conveyor belt 21a and be collected in the collection box 32b. Such control of the blowing of gas is executed by the control unit 43 based on various information such as position information of the tablet T, height information of the tablet T, printability information, and print quality information.

[0080] In step S10, the control unit 43 determines whether printing has ended. For example, the number of printed tablets T is counted, and when the number reaches a predetermined production number, it is determined that printing has ended. When it is determined that printing has ended (Yes in step S10), the process ends. On the other hand, when it is determined that printing has not ended (No in step S10), the process returns to step S1. Regarding the determination of the end of printing, in response to a user input operation on the input device 40a, for example, when the user presses a printing end button, it may be determined that printing has ended.

[0081] In the above step S3, when it is determined that the height of the tablet T on the conveyor belt 21a is abnormal (Yes in step S3), in step S11, the conveyor speed of the conveyor belt 21a is decreased by the control unit 43. For example, the conveyor speed may be gradually or stepwise decreased at a certain rate from a predetermined normal speed, or may be gradually or stepwise decreased at a random rate. The predetermined normal speed is decreased to a predetermined speed, and this predetermined speed is desirably a conveyor speed about 1 / 10 of the normal speed.

[0082] For example, the predetermined speed is determined based on the distance between the position directly below the detection unit 22 on the conveyor belt 21a and the position directly below the inkjet head 24, and the time required for the ejection surface of the inkjet head 24 to move from a predetermined normal position H1 to a predetermined retracted position H3. The distance between the position directly below the detection unit 22 on the conveyor belt 21a and the position directly below the inkjet head 24 is, for example, the distance between the detection position where the tablet T on the conveyor belt 21a is detected by the detection unit 22 and the position directly below the upstream end of the conveyor direction A1 of the inkjet head 24.

[0083] In step S12, the inkjet head 24 is lifted by the moving mechanism 26. For example, the inkjet head 24 rises until its ejection surface moves from a predetermined normal position H1 to a predetermined retracted position H3 (see FIG. 9). As a result, the distance between the conveyance surface of the conveyance belt 21a and the ejection surface of the inkjet head 24 expands to a predetermined retracted distance. This predetermined retracted distance is such that even if a tablet T in an abnormal height state reaches directly below the inkjet head 24 by the conveyance belt 21a in that state, it can pass directly below the inkjet head 24 without colliding with the inkjet head 24.

[0084] In step S13, printing on a plurality of tablets T including the tablet T in an abnormal height state, that is, the abnormally high tablet T, and located before and after it is restricted by the control unit 43. For example, the inkjet head 24 is lifted by the moving mechanism 26 and ejection is interrupted. As a result, the abnormally high tablet T and the tablets T conveyed before and after it (that is, the tablets T that pass directly below the inkjet head 24 when the inkjet head 24 is positioned higher than the normal position H1) are no longer printed by the inkjet head 24. As a result, the occurrence of defective printed (unqualified printed) tablets T can be suppressed. That is, the control unit 43 stops printing by the inkjet head 24 on the tablet T at the same time as it lifts the inkjet head 24 by the moving mechanism 26.

[0085] In step S14, it is determined by the control unit 43 whether or not the abnormally high tablet T has passed directly below the inkjet head 24. If it is determined that the abnormally high tablet T has passed directly below the inkjet head 24 (Yes in step S14), the process proceeds to step S15. For example, the control unit 43 determines that the abnormally high tablet T has passed directly below the inkjet head 24 when a predetermined time has elapsed since the tablet T on the conveyance belt 21a was detected by the detection unit 22. Note that whether or not the abnormally high tablet T has passed directly below the inkjet head 24 may also be detected by the position detector 22e.

[0086] For example, the predetermined time is determined based on the conveying speed of the tablet T (changing conveying speed), the distance between the position directly below the detection unit 22 on the conveyor belt 21a and the position directly below the inkjet head 24, and the movement amount (rotation amount) of the conveyor belt 21a. Note that the distance between the position directly below the detection unit 22 on the conveyor belt 21a and the position directly below the inkjet head 24 here is, for example, the distance between the detection position where the detection unit 22 detects the tablet T on the conveyor belt 21a and the position directly below the downstream end of the inkjet head 24 in the conveying direction A1.

[0087] In step S15, the inkjet head 24 is lowered by the movement mechanism 26. For example, the inkjet head 24 is lowered until its ejection surface moves from a predetermined retracted position H3 to a predetermined normal position H1 (see FIG. 9). As a result, the distance between the conveyance surface of the conveyor belt 21a and the ejection surface of the inkjet head 24 returns to the predetermined normal distance (the distance when the inkjet head 24 is located at the normal position H1).

[0088] In step S16, the control unit 43 returns the conveying speed of the conveyor belt 21a to its original speed, and the process proceeds to step S9. For example, the conveying speed may be increased gradually or stepwise at a constant rate to a predetermined normal speed, or may be increased gradually or stepwise at a random rate. The predetermined normal speed is set in advance and stored, for example, in the storage unit 42. However, the predetermined normal speed may be changed according to predetermined conditions, or may be changed according to a user's input operation on the input device 40a.

[0089] Even during such a printing process, the cooling unit 61 (see FIG. 3) continuously operates to take in outside air and supply it to the first region R1. The temperature of the air supplied to the first region R1 is at least lower than the temperature in the second region R2. The air with a temperature lower than the temperature in the second region R2 becomes cooling air. By supplying the cooling air to the first region R1, the cooling air touches each inkjet head 24, and each inkjet head 24 is cooled. At the same time, after the cooling air passes through each inkjet head 24, it flows into the suction hole 21g for holding the tablet T, making it difficult for the air current from the heat source 62 side to be sucked into the suction hole 21g. Alternatively, the air from the heat source 62 side is cooled by the cooling air and is sucked into the suction hole 21g. As a result, the temperature of the air flowing into the vicinity of the suction hole 21g decreases, and ultimately the temperature in the vicinity of the inkjet head 24 decreases.

[0090] Here, the target temperature in the vicinity of the inkjet head 24 is desirably, for example, 20 degrees to 25 degrees. If the cooling by the cooling unit 61 is not performed, the temperature in the vicinity of the inkjet head 24 will exceed 25 degrees. When the temperature in the vicinity of the inkjet head 24 exceeds 25 degrees, the likelihood of problems occurring in the inkjet head 24 (such as a decrease in ink viscosity resulting in poor ejection) increases. Therefore, by supplying the cooling air by the cooling unit 61 to lower the temperature in the vicinity of the inkjet head 24, it is possible to suppress a decrease in the viscosity of the ink in the inkjet head 24 and drying of the ink near the nozzle 24a, thereby suppressing the occurrence of poor ejection and the occurrence of printing defects. Also, it is possible to suppress an increase in the temperature of the ink in the inkjet head 24, appropriately maintain the ink, and suppress the deterioration of the ink. According to experiments, it was confirmed that by performing the supply of the cooling air by the cooling unit 61, the temperature in the vicinity of the inkjet head 24 can be lowered from 28 degrees to 31 degrees to about 23 degrees.

[0091] Furthermore, a measuring device (not shown) for measuring the temperature near the inkjet head 24 may be provided. When the measurement result of this measuring device exceeds a predetermined temperature (for example, 24 degrees), the amount of cooling air supplied from the cooling unit 61 may be increased. Alternatively, when the measurement result by the measuring device exceeds a predetermined temperature, printing by the inkjet head 24 may be stopped. By doing so, the occurrence of printing defects can be prevented. Note that the measuring device for measuring the temperature near the inkjet head 24 may be provided near the inkjet head 24, or may be provided on the inkjet head 24 itself to measure the surface temperature of the inkjet head 24 itself. That is, the temperature near the inkjet head 24 includes the temperature of the inkjet head 24 itself.

[0092] Also, the cooling unit 61 is provided so as to blow out cooling air avoiding the ejection surface of each inkjet head 24 that moves by the moving mechanism 26. Thereby, even when each inkjet head 24 moves by the moving mechanism 26 during retraction from the tablet T or during maintenance, etc., the cooling air blown out from the cooling unit 61 does not directly hit the ejection surface of each inkjet head 24, so that the ink near the nozzle 24a can be suppressed from drying and sticking. Therefore, the occurrence of ejection defects can be suppressed, and the occurrence of printing defects can be suppressed.

[0093] Also, by discharging the air in the second region R2 to the outside of the apparatus by the cooling unit 161, the inside of the second region R2 is made into a negative pressure. When the inside of the second region R2 becomes a negative pressure, the heat generated in the second region R2 is suppressed from flowing into the first region R1. Also, when the inside of the second region R2 becomes a negative pressure, the cooling gas from the cooling unit 61 easily flows into the second region R2.

[0094] Also, the length of the partition member 54 in the X direction is the same as the length of the conveying unit 21 in the X direction. Thereby, it is possible to prevent the suction holes 21g that are not sucking the tablets T in the conveying belt 21a from allowing the air in the second region R2 to flow in. Further, the upper end of the partition member 54 is connected to the ceiling of the housing 51. Warm air tends to go upward in the space. Therefore, by connecting the upper end of the partition member 54 to the ceiling of the housing 51, it is possible to prevent the air warmed in the second region R2 from flowing into the first region R1.

[0095] Also, in response to the detection of height abnormality by the detection unit 22, the control unit 43 decreases the conveyance speed of the conveyance belt 21a and further increases the distance between the surface of the inkjet head 24 on the conveyance belt 21a side and the surface of the conveyance belt 21a on the inkjet head 24 side. Thereby, the tablets T in an abnormal height state on the conveyance belt 21a can pass through without colliding with the inkjet head 24. Therefore, it becomes possible to suppress damage to the inkjet head 24 and breakage of the tablets T, so that it is possible to suppress adverse effects such as an increase in the number of maintenance times, an extension of the maintenance time, and breakage of the tablets T, and to efficiently perform printing on the tablets T.

[0096] The control unit 43 raises the inkjet head 24, and as soon as the tablet T with an abnormal height passes directly below the inkjet head 24, returns the inkjet head 24 to its original height position (normal position H1), returns the conveying speed of the conveyor belt 21a to the normal speed, and resumes printing at the normal conveying speed. Printing by the inkjet head 24 is interrupted only during the period when the inkjet head 24 is raised, the tablet T with an abnormal height passes below the inkjet head 24, and the inkjet head 24 is lowered, and printing is performed when the inkjet head 24 is in the normal position H1, so that printing can be performed efficiently on the tablets T. In other words, printing cannot be performed on tablets following the tablet T with an abnormal height that are present at a distance corresponding to the length of the inkjet head 24 in the conveying direction A1, but printing can be resumed after the tablet T with an abnormal height has completely passed the downstream end of the inkjet head 24 in the conveying direction A1, and this minimizes the number of tablets T that are not printed due to the conveyance of the tablet T with an abnormal height. In addition, the printing and inspection processes for tablets T subsequent to the height abnormal tablet T will also be restricted, and these tablets T will also become non-printed tablets.

[0097] As long as the height-abnormal tablet T and the subsequent tablets (tablets present at a distance equal to the length of the inkjet head 24 in the conveying direction A1) have passed the inkjet head 24 and the inkjet head 24 has returned to its normal position H1, the control unit 43 can resume printing on the tablets T by the inkjet head 24. If the conveying speed of the conveyor belt 21a has been reduced, printing may be resumed after the conveying speed is returned to the normal speed as described above, but printing may also be resumed with the conveying speed reduced and then the conveying speed returned to its original speed while printing continues.

[0098] Here, usually, the supply speed at which the tablets T are supplied from the supply device 10 to the conveying unit 21 (the conveying speed at which the tablets T are conveyed by feeders such as the alignment feeder 12 and the delivery feeder 13) is always set slower than the conveying speed at which the conveying belt 21a conveys the tablets T. For this reason, when the control unit 43 reduces the conveying speed of the conveying belt 21a so as to maintain a predetermined speed difference between the supply speed of the supply device 10 and the conveying speed of the conveying belt 21a, the supply speed of the supply device 10 may also be reduced. Thereby, it is possible to prevent the tablets T from clogging in feeders such as the alignment feeder 12 and the delivery feeder 13.

[0099] Further, the control unit 43 may control the supply device 10 to stop the supply of new tablets T as soon as a tablet T in an abnormal height state is detected. Thereby, in response to the occurrence of a tablet T in an abnormal height state, new tablets T are not supplied onto the conveying belt 21a. The maintenance unit 27 of the inkjet head 24 enters between the inkjet head 24 and the conveying belt 21a to perform maintenance. At this time, the inkjet head 24 retreats to a position higher than the normal position H1 in order to create a space for the maintenance unit 27 to enter. For this reason, as soon as the tablets T on the conveying belt 21a are collected and a state where new tablets T are not supplied to the conveying belt 21a is achieved, the maintenance work of the inkjet head 24 can be performed. Also, at the timing of performing the maintenance of the inkjet head 24, the maintenance of the conveying belt 21a (and the suction holes 21g) may be performed.

[0100] Further, the control unit 43 restricts the ink ejection of the inkjet head 24 for the tablets T that have passed directly below the detection unit 22 during the period when the conveying speed of the conveying belt 21a is reduced, and controls the recovery device 30 to recover the tablets T that have passed directly below the detection unit 22 during the period when the conveying speed of the conveying belt 21a is reduced as reusable non-printed tablets, that is, as recycled products. Thereby, the tablets T that have passed directly below the detection unit 22 during the period when the conveying speed of the conveying belt 21a is reduced can be recovered as recycled products.

[0101] Furthermore, in order to change the distance between the placement surface of the conveyor belt 21a and the ejection surface of the inkjet head 24, the inkjet head 24 is moved by the movement mechanism 26, but this is not limiting, and for example, the conveyor belt 21a may be moved by the movement mechanism 26. This movement of the conveyor belt 21a may be achieved by moving the entire conveyor unit 21 by the movement mechanism 26, or may be achieved by moving a part of the conveyor belt 21a facing the inkjet head 24 by the movement mechanism 26.

[0102] Here, when the conveyed object is a tablet T, the speed at which the tablet passes under the inkjet head 24 is orders of magnitude faster than when the conveyed object is, for example, paper. Furthermore, the relative size difference between the conveyed object and the inkjet head 24 is large, and the conveyance interval between each conveyed object is also narrow. Therefore, it is not enough to simply prevent collisions between the conveyed object and the inkjet head 24. It is important to devise a way to prevent collisions while minimizing the number of tablets T that are affected, such as by being unable to print, by retracting the inkjet head 24 to prevent the collision. Furthermore, if a tablet T with an abnormal height is detected and the operation of the entire device is stopped and the tablets T on the conveyor belt 21a are collected as unprinted (unprinted tablets), productivity will be significantly reduced. Therefore, according to the present embodiment described above, it is possible to solve tablet-specific problems not encountered in paper printing. When printing on tablets T, unlike printing on paper, a single inkjet head 24 may be used to print on multiple tablets T arranged in a direction perpendicular to the conveyance direction A1 in a horizontal plane.

[0103] As described above, according to the embodiment, the tablet printing apparatus 1 includes a conveyance unit 21 provided in the first region R1 that sucks and holds the tablet T in the suction holes 21g and conveys it, an inkjet head 24 provided in the first region R1 that performs printing on the tablet T conveyed by the conveyance unit 21, a heat source 62 provided in the second region R2 connected to the first region R1, and a cooling unit 61 that supplies a gas at a temperature lower than that of the second region R2 to the first region R1. Thereby, since it becomes possible to supply a gas at a temperature lower than that of the second region R2 to the first region R1, the temperature in the vicinity of the inkjet head 24 in the first region R1 can be lowered. Therefore, it is possible to suppress a decrease in the viscosity of the ink in the inkjet head 24 and drying of the ink near the nozzles 24a, and to suppress the occurrence of ejection failure, so that the occurrence of printing failure can be suppressed. Further, it is possible to suppress an increase in the temperature of the ink in the inkjet head 24 and to appropriately maintain the ink, so that deterioration of the ink can be suppressed.

[0104] <Other Embodiments> In the foregoing description, printing is performed on the tablet T using the tablet printing apparatus 1 (tablet printing method) according to an embodiment. This can also be rephrased as performing printing on the tablet T using the tablet printing apparatus 1 (tablet printing method) according to an embodiment and manufacturing the printed tablet T. That is, the tablet printing apparatus 1 can be rephrased as a tablet manufacturing apparatus, and the tablet printing method can be rephrased as a tablet manufacturing method.

[0105] Also, in the foregoing description, printing one side of the tablet T has been exemplified, but the present invention is not limited thereto. For example, the printing apparatuses 20 are combined into one unit, and the units are arranged one above the other. The tablet T printed by the upper printing apparatus (first printing apparatus) 20 is inverted and delivered to the lower printing apparatus (second printing apparatus) 20, and printing on the tablet T by the lower printing apparatus 20 is executed so that both sides of the tablet T are printed.

[0106] In the above description, it was exemplified that the tablets T are conveyed in two rows, but it is not limited thereto. The number of rows may be an example, or may be multiple rows of three or more, and is not particularly limited. The number of the conveyor belts 21a may also be two or more, and is not particularly limited. Also, the number of the inkjet heads 24 may be one or three or more, and is not particularly limited.

[0107] In the above description, it was exemplified that the cover 53 is formed of the main body 53b and the door portion 53c, but it is not limited thereto. For example, the side surface of the cover 23a on the inkjet head 24 side and the side surface of the cover 25a on the inkjet head 24 side may function as the side surface of the main body 53b. Also, the holding portion 51a of the housing 51 may function as the ceiling of the main body 53b. Further, the ceilings of the cover 23a, the cover 25a, and the cover 53 may be integrated. Also, the cover 53 may be integrated without distinguishing between the main body 53b and the door portion 53c.

[0108] In the above description, the cover 23a covering the first imaging unit 23 and the cover 25a covering the second imaging unit 25 were exemplified, but it is not limited thereto. For example, the cover 23a and the cover 25a are not essential, and the cover 53 may have a configuration that surrounds at least the periphery and the upper side of the inkjet head 24 above the conveying unit 21.

[0109] In the above description, as the opening 54a of the partition member 54, the case where the shape of the opening 54a is a notch is exemplified, but the present invention is not limited thereto. For example, when there is no holding portion 51a, the opening 54a may be a hole having a width that allows the maintenance portion 27 to move back and forth between the first region R1 and the second region R2. In this case, the lower end of the opening 54a is provided so as to be positioned at a height at which the maintenance portion 27 can move back and forth between the first region R1 and the second region R2. When the partition member 54 is connected to the ceiling of the housing 51, the first region R1 and the second region R2 are substantially partitioned by the partition member 54. In this case, most of the heat generated in the second region R2 tends to flow into the first region R1 through the opening 54a. However, since the cooling gas from the cooling unit 61 is supplied to the space blocked by the cover 53, it is possible to further suppress the heat generated in the second region R2 from flowing into the first region R1.

[0110] In the above description, as the inkjet head 24, a printing head in which the nozzles 24a are arranged in a row is exemplified, but the present invention is not limited thereto, and for example, a printing head in which the nozzles 24a are arranged in a plurality of rows may be used.

[0111] In the above description, the case where the inkjet head 24 is provided such that the direction in which the nozzles 24a are arranged is perpendicular to the conveyance direction A1 in the horizontal plane is exemplified, but the present invention is not limited thereto, and for example, the inkjet head 24 may be provided such that the direction in which the nozzles 24a are arranged intersects the conveyance direction A1 in the horizontal plane.

[0112] In the above description, it is assumed that the tablets T are supplied randomly on the conveyance belt 21a instead of at regular intervals, but the present invention is not limited thereto, and they may be supplied at regular intervals. In the above description, it is assumed that the tablets T are sucked and held by the suction holes 21g formed on the conveyance belt 21a, but the present invention is not limited thereto, and they may be housed and held in a pocket or the like and conveyed, or they may be held and conveyed on the conveyance belt 21a by their own weight.

[0113] Also, in the above description, the control unit 43 was exemplified as determining whether or not the height of the tablet T is abnormal based on the height information regarding the height of the tablet T detected by the detection unit 22, but it is not limited to this. For example, based on the image of the tablet T obtained by the first imaging unit 23, the area, length, and shape when the tablet T supplied to the conveyor belt 21a is viewed in plan (indirectly detecting the height of the tablet T) may be detected to obtain height information. That is, when the area or length of the tablet T in plan view falls below a threshold value, it may be determined that the height of the tablet T is abnormal. Alternatively, a position about 1 mm lower than the normal position H1 may be set as a threshold value with respect to the normal position H1 of the inkjet head 24.

[0114] Also, in the above description, the control unit 43 was exemplified as causing the inkjet head 24 to perform printing until the inkjet head 24 moves to the retracted position H3 or until the tablet T located one upstream of the tablet T with abnormal height when the tablet T with abnormal height is detected by the detection unit 22, but it is not limited to this. For example, when the tablet T with abnormal height is detected by the detection unit 22, the printing by the inkjet head 24 may be interrupted and the inkjet head 24 may be moved from the normal position H1 to the retracted position H3. In this case, the conveyance speed of the conveyor belt 21a only needs to be reduced to a speed at which it is possible to move to the retracted position H3 during the period from when the tablet T with abnormal height is detected until the tablet T with abnormal height reaches the inkjet head 24. Alternatively, the inkjet head 24 may be controlled to move to the retracted position H3 so that the tablets T whose printing is restricted are several (for example, about 10) before and after the tablet T with abnormal height (or the time when about 10 are predicted to be conveyed). In this case, the speed difference before and after the reduction in the conveyance speed of the conveyor belt 21a can be small, and the number of tablets printed per unit time can be increased.

[0115] In the above description, an example was given of gradually or stepwise reducing the conveyance speed of the conveyance belt 21a. However, the present invention is not limited to this. When the detection unit 22 detects that the height of the tablet T has exceeded a predetermined threshold value, the conveyance speed may be rapidly reduced to the target conveyance speed. Even when returning the conveyance speed of the conveyance belt 21a from the reduced speed to the normal speed, similar to the case of reducing the speed, it may be gradually or stepwise returned, or may be rapidly returned. In any case, gradually or stepwise changing the conveyance speed can prevent the tablet T from detaching from the conveyance belt 21a.

[0116] Here, the aforementioned tablet T can include tablets used for pharmaceuticals, food, cleaning, industrial, or fragrance purposes. Also, as the tablet T, there are uncoated tablets (plain tablets), sugar-coated tablets, film-coated tablets, enteric-coated tablets, gelatin-coated tablets, multilayer tablets, nucleated tablets, etc., and various capsule tablets such as hard capsules and soft capsules can also be included in the tablet T. Furthermore, as the shape of the tablet T, there are various shapes such as disk shape, lens shape, triangle, ellipse, etc. Also, when the tablet T to be printed is for pharmaceuticals or food, edible ink is suitable as the ink to be used. As this edible ink, any of synthetic pigment ink, natural pigment ink, dye ink, and pigment ink may be used.

[0117] As described above, some embodiments of the present invention have been explained. However, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and its equivalent scope.

Explanation of Reference Numerals

[0118] 1 Tablet printing device 10 Feeding device 11 Hopper 12 Alignment feeder 13 Delivery Feeder 20 Printing Device 21 Conveyor Section 21a Conveyor Belt 21b Driving Pulley 21c Driven Pulley 21d Motor 21e Position Detector 21f Suction Chamber 21g Suction Hole 22 Detection Section 23 First Imaging Section 23a Cover 24 Inkjet Head 24a Nozzle 25 Second Imaging Section 25a Cover 26 Moving Mechanism 26a Arm 26b Arm Moving Mechanism 27 Maintenance Section 27a Wiping Section 27b Tray 28 Drying Section 30 Recovery Device 31 Recycled Product Recovery Section 31a Injection Nozzle 31b Recovery Box 32 Defective Product Recovery Section 32a Injection Nozzle 32b Recovery Box 33 Non-defective Product Recovery Section 33b Recovery Box 33a Injection Nozzle 40 Control Device 40a Input Device 40b Output Device 41 Image Processing Section 42 Memory Section 43 Control Section 51 Housing 51a Holding Section 52 Door 52a Opening 53 Cover 53a Ventilation Section 53b Main Body 53c Door Section 54 Partition member 54a Opening 54b Plate 54c Frame 55 Door 61 Cooling section 62 Heat source 161 Cooling section A1 Conveying direction A2 Conveying direction Ha Movement range H1 Normal position H2 Maintenance position H3 Retracted position T Tablet

Claims

1. A conveying unit provided in a first area, which sucks and holds a tablet in a suction hole and conveys the tablet; An inkjet head provided in the first area, which performs printing on the tablet conveyed by the conveying unit; A heat source provided in a second area that is arranged to be aligned with the first area in a direction orthogonal to the conveying direction of the tablet conveyed by the conveying unit, and is provided in the second area connected to the first area; A cooling unit that supplies a gas at a temperature lower than the temperature of the second area from the first area side toward the second area in the first area; A moving mechanism provided in the second area, which moves the inkjet head so as to change the distance between the surface of the inkjet head on the conveying unit side and the surface of the conveying unit on the inkjet head side; Comprising; The cooling unit is provided so as to blow out the gas while avoiding the surface of the inkjet head on the conveying unit side that moves by the moving mechanism; A tablet printing apparatus further comprising a partition member that is a wall for partitioning the first area and the second area and has an opening for connecting the moving mechanism to the inkjet head.

2. A conveying unit provided in a first area within a housing sucks and holds a tablet in a suction hole and conveys the tablet; An inkjet head provided in the first area performs printing on the tablet conveyed by the conveying unit; In a state where a heat source exists in a second area that is arranged to be aligned with the first area within the housing in a direction orthogonal to the conveying direction of the tablet conveyed by the conveying unit and is connected to the first area, a cooling unit supplies a gas at a temperature lower than the temperature of the second area from the first area side toward the second area while avoiding the surface of the inkjet head on the conveying unit side; including, The first area and the second area are partitioned by a partition member having an opening for connecting an inkjet head provided in the first area and a moving mechanism provided in the second area for changing the distance between the surface of the inkjet head on the conveying unit side and the surface of the conveying unit on the inkjet head side; A tablet printing method.

Images