JP7394681B2 - Tablet printing device and tablet manufacturing method - Google Patents

Description

Embodiments of the present invention relate to a tablet printing device and a tablet manufacturing method.

In order to print identification information (an example of information) such as letters and marks on tablets, a printing technique is known that uses an inkjet head. Tablet printing devices using this technology transport tablets using a conveyor or other transport device, and eject ink from each nozzle of an inkjet head placed above the transport device toward the tablets passing below the inkjet head. , printing identification information on the tablet. In this tablet printing device, a detection unit that inspects the position and appearance of the tablet is placed upstream of the inkjet head in the tablet transport direction, and based on the detection information of the detection unit, it is determined whether or not to print on the tablet. , printing may be done on printable tablets.

Japanese Unexamined Patent Publication No. 7-081050

The problem to be solved by the present invention is to provide a tablet printing device and a tablet manufacturing method that can perform high-quality printing.

The tablet printing device according to the embodiment of the present invention includes:
a transport unit that transports tablets to be printed;
a first acquisition unit that acquires a position in the conveyance direction of the tablet conveyed by the conveyance unit;
The upper surface of the tablet, which is provided downstream of the first acquisition unit in the conveyance direction of the tablet, and is conveyed by the conveyance unit based on the position of the tablet in the conveyance direction acquired by the first acquisition unit. a first imaging unit that images the
a second acquisition unit that acquires the position in the conveyance direction of the tablet conveyed by the conveyance unit from an image including the top surface of the tablet obtained by the first imaging unit;
A side surface of the tablet that is provided downstream of the first imaging unit in the transport direction of the tablet and that is transported by the transport unit based on the position of the tablet in the transport direction that is acquired by the second acquisition unit. a second imaging unit that images the
The second imaging unit is provided downstream of the tablet in the transport direction, and prints on the tablet transported by the transport unit based on the position of the tablet in the transport direction acquired by the second acquisition unit. a print head that performs
has.

The tablet manufacturing method according to the embodiment of the present invention includes:
a step of conveying the tablet to be printed by a conveying section;
a step of acquiring, by a first acquisition unit, the position in the conveyance direction of the tablet conveyed by the conveyance unit;
Based on the position of the tablet in the transport direction acquired by the first acquisition unit, a first imaging timing for imaging the top surface of the tablet transported by the transport unit, and a first imaging timing for imaging the top surface of the tablet transported by the transport unit a step of setting a second imaging timing for imaging the side surface of the tablet by a setting unit;
a step of imaging the top surface of the tablet transported by the transporting unit with a first imaging unit at the first imaging timing set by the setting unit;
a step of acquiring, by a second acquisition unit, the position of the tablet in the conveyance direction of the tablet conveyed by the conveyance unit from an image including the top surface of the tablet obtained by the first imaging unit;
Correcting the second imaging timing by a correction unit based on the position of the tablet in the transport direction acquired by the second acquisition unit;
a step of imaging a side surface of the tablet transported by the transport unit with a second imaging unit at the second imaging timing corrected by the correction unit;
a printing step of printing on the tablet conveyed by the conveyance unit based on the position of the tablet in the conveyance direction acquired by the second acquisition unit;
has
In the correcting step, the second imaging timing is corrected to a timing at which a position in the transport direction of the tablet transported by the transport unit overlaps a center position in the transport direction of an imaging area of the second imaging unit. do.

According to embodiments of the present invention, high quality printing can be performed.

1 is a diagram showing a schematic configuration of a tablet printing device according to an embodiment. FIG. 1 is a plan view showing a part of the schematic configuration of a tablet printing device according to an embodiment. FIG. 3 is a diagram showing a schematic configuration of a second imaging unit according to an embodiment. FIG. 7 is a diagram for explaining an image obtained by a second imaging unit according to an embodiment. FIG. 3 is a diagram for explaining timing setting and correction according to an embodiment. 3 is a flowchart showing the flow of print processing according to an embodiment. FIG. 7 is a diagram for explaining another image (in the case where the tablet has a score line) obtained by the second imaging unit according to an embodiment.

<One form of implementation>
One embodiment will be described with reference to the drawings.

(Basic configuration)
As shown in FIG. 1, the tablet printing apparatus 1 according to the embodiment includes a supply section 10, a conveyance section 20, a detection section 30, a first imaging section 40, a second imaging section 50, It includes a printing section 60, a third imaging section 70, a collection section 80, and a control device 90.

The supply section 10 has a hopper 11 and a chute 12. The supply section 10 is configured to be able to supply the tablets T to the conveyance section 20, and is positioned at one end side of the conveyance section 20. The hopper 11 accommodates a large number of tablets T, and sequentially supplies the accommodated tablets T to the shooter 12. The shooter 12 arranges the tablets T supplied from the hopper 11 in a line and supplies them to the transport section 20. The supply unit 10 is electrically connected to a control device 90, and its driving is controlled by the control device 90. Note that the tablet T is circular in plan view and has substantially flat upper and lower surfaces.

The conveyance unit 20 includes a conveyance belt 21, a drive pulley 22, a plurality of (three in the example of FIG. 1) driven pulleys 23, a motor (drive unit) 24, a position detector 25, and a suction chamber (suction unit) 26. ing. The conveyor belt 21 is an endless belt, and is stretched around a drive pulley 22 and each driven pulley 23 . The drive pulley 22 and each driven pulley 23 are rotatably provided in the device body, and the drive pulley 22 is connected to a motor 24. The motor 24 is electrically connected to a control device 90, and its driving is controlled by the control device 90. The position detector 25 is a device such as an encoder, and is attached to the motor 24. This position detector 25 is electrically connected to a control device 90 and transmits a detection signal to the control device 90. The conveyor unit 20 rotates the conveyor belt 21 together with each driven pulley 23 by the rotation of the driving pulley 22 by the motor 24, and conveys the tablets T on the conveyor belt 21 in the rotation direction of arrow H1 in FIG. 1, that is, in the conveyance direction H1. do.

As shown in FIG. 2, the conveyor belt 21 is provided with a plurality of circular suction holes 21a. These suction holes 21a are through holes that suck the tablets T, and are arranged in a line along the conveyance direction H1 so as to form one conveyance path. Each suction hole 21a is connected to the suction chamber 26 through a suction path (not shown) formed in the suction chamber 26 (see FIG. 1), and it is possible to obtain suction force from the suction chamber 26. It has become. A suction section such as a pump is connected to the suction chamber 26 via a suction pipe (none of which is shown), and the pressure inside the suction chamber 26 is reduced by the operation of the suction section. The suction tube is connected to approximately the center of the side surface of the suction chamber 26 (a surface parallel to the transport direction H1). Further, the intake section is electrically connected to a control device 90, and its driving is controlled by the control device 90. When the pressure inside the suction chamber 26 is reduced, the tablets T placed on each suction hole 21a of the conveyor belt 21 are suctioned by the suction chamber 26 and held on the conveyor belt 21.

The detection unit 30 is located downstream in the transport direction H1 from the position where the supply unit 10 is provided, and is provided above the transport belt 21. This detection unit 30 detects the tablet T on the conveyor belt 21 and functions as a trigger sensor for each device located downstream. The detection unit 30 includes a displacement sensor, a proximity sensor, and the like. For example, various laser sensors such as a reflective laser sensor are used as the displacement sensor. The detection unit 30 is electrically connected to the control device 90 and transmits a detection signal to the control device 90.

The first imaging unit 40 is located downstream in the transport direction H1 from the position where the detection unit 30 is provided, and is provided above the transport belt 21. The first imaging unit 40 performs imaging at a first imaging timing when the tablet T reaches an imaging position directly below the first imaging unit 40 based on a detection signal (for example, a trigger signal) from the detection unit 30. A first image including the top surface of the tablet T is acquired, and the acquired first image is transmitted to the control device 90. The first imaging timing is the timing when the position of the tablet T on the transport belt 21 in the transport direction H1 overlaps with the center position of the imaging area (imaging range) of the first imaging unit 40 in the transport direction H1. The first image is used to understand cracks and chips (for example, cracks or chips) and dirt (for example, deposits) on the tablet T, as well as the position and posture of the tablet T. As the first imaging unit 40, various cameras having an imaging element such as a CCD (charge coupled device) or a CMOS (complementary metal oxide semiconductor) are used. The first imaging unit 40 is electrically connected to a control device 90, and its driving is controlled by the control device 90. Illumination for imaging is also provided if necessary.

The second imaging unit 50 includes a camera 51 and a light guide member 52. The first imaging unit 40 described above images the top surface of the tablet T being transported by the transporting unit 20, while the second imaging unit 50 images the side surface of the tablet T being transported by the transporting unit 20.

The camera 51 is located downstream in the transport direction H1 from the position where the first imaging unit 40 is provided, and is provided above the transport belt 21. This camera 51 performs imaging at a second imaging timing when the tablet T reaches the imaging position directly below the camera 51 based on a detection signal (for example, a trigger signal) from the detection unit 30, and captures a second image including the side surface of the tablet T. , and transmits the obtained second image to the control device 90. The second imaging timing is the timing when the position of the tablet T on the transport belt 21 in the transport direction H1 overlaps with the center position of the imaging area of the camera 51 in the transport direction H1. The second image is used to identify cracks, chips (for example, cracks or chips), stains (for example, deposits), etc. on the tablet T. As the camera 51, it is possible to use various cameras having an image sensor such as a CCD or a CMOS, similar to the above-described image capturing section 40. The camera 51 is electrically connected to a control device 90, and its driving is controlled by the control device 90. Illumination for imaging is also provided as needed.

As shown in FIGS. 2 and 3, the light guide member 52 is composed of a plurality of prisms 52a (six in the example of FIG. 2). These prisms 52a are positioned below the camera 51, and are arranged in pairs in a horizontal plane in a ring shape so as to face each other in parallel. It is formed so that an image of all sides (the outer circumferential surface for one circumference) of the camera 51 is focused on the image pickup element of the camera 51. The center position of the ring formed by each prism 52a and the center position of the imaging area of the camera 51 are located on the same vertical line.

All sides of the tablet T are imaged by a camera 51 through a light guide member 52, as shown in FIG. When imaging is performed by the camera 51, as shown in FIG. 4, an image including all sides of the tablet T, that is, an individual image of the side surface of the tablet T by each prism 52a is obtained. The individual images of the side surfaces of the tablet T formed by these prisms 52a are arranged in a ring shape surrounding the optical axis of the camera 51, and exist around the center of the image. In addition, in FIG. 4, the top surface of the tablet T is illustrated in order to grasp the positional relationship between the individual images of the side surfaces of the tablet T by each prism 52a and the top surface of the tablet T. In each image of the side surface of the tablet T, the symbol M1 is a surface corresponding to the surface where the tablet T is in contact with the conveyor belt 21 (hereinafter referred to as the lower surface M1), and the symbol M2 is a surface corresponding to the opposite surface of M1. (hereinafter referred to as upper surface M2). In addition, in the light guide member 52, the number and arrangement of each prism 52a are adjusted so that the camera 51 can image the entire side surface (outer circumferential surface for one circumference) of the tablet T.

Here, the large number of tablets T transported by the transport section 20 may include tablets with cracks, chips, or stains. For example, "cracked or chipped" is a state in which a portion of the tablet T is chipped or broken, and a portion of the tablet T has a recessed portion. Such cracks and chips are likely to occur at the corners of the tablet T. Moreover, "stain" refers to a state in which there is a deposit on a part of the tablet T. The tablet T shown in FIG. 4 has cracks or stains on the corners of the upper surface. When a crack or a stain is present on the tablet T, the reflectance of the concave part of the crack or the stain is lower than that of other parts of the tablet T. Note that depending on the type of deposit that becomes a stain, the reflectance of the stain may be higher than that of other parts of the tablet T. For example, as shown in FIG. 4, a black triangle (dark portion) B1 exists on the upper surface M2 in three of all images of the side surface of the tablet T taken by each prism 52a. The black triangles shown in FIG. 4 schematically represent dark parts that appear in the captured image, and the dark parts that appear in the actually obtained image are not necessarily triangular.

The aforementioned black triangle B1 is caused by cracks, chips, or dirt. In other words, if the black triangle B1 is present in any of the individual images of the side surfaces of the tablet T by each prism 52a, it means that there is a crack, a chip, or a stain. Moreover, when the black triangle B1 exists on the upper surface M2 (see FIG. 4), it can be seen that the upper surface of the tablet T has cracks, chips, or stains. On the other hand, if the black triangle B1 is present on the lower surface M1, it can be seen that the lower surface of the tablet T has cracks, chips, or stains. Note that if the tablet T has cracks, chips, or stains, at least two or more black triangles B1 are present in all images of the side surface of the tablet T taken by each prism 52a. Therefore, if there is only one black triangle B1 in all images of the side surface of the tablet T taken by each prism 52a, the detection is determined to be an erroneous detection, rather than the tablet T being cracked or chipped. is also possible.

Returning to FIGS. 1 and 2, the printing unit 60 has an inkjet head (an example of a print head) 61, and the inkjet head 61 prints on the tablets T on the conveyor belt 21. The inkjet head 61 is positioned downstream in the transport direction H1 from the position where the second imaging unit 50 is provided, and is provided above the transport belt 21. As shown in FIG. 2, this inkjet head 61 has a plurality of nozzles 61a (for example, several hundred to several thousand), and the direction in which the nozzles 61a are lined up (nozzle row) is in the horizontal plane and in the transport direction. It is provided so as to be perpendicular to H1 (an example of crossing). The inkjet head 61 individually discharges ink from each nozzle 61a by driving a piezoelectric element or the like. As the inkjet head 61, various inkjet heads having drive elements such as piezoelectric elements, heating elements, or magnetostrictive elements are used. The inkjet head 61 is electrically connected to a control device 90, and its driving is controlled by the control device 90.

The third imaging unit 70 is located downstream in the transport direction H1 from the position where the printing unit 60 is provided, and is provided above the transport belt 21. The third imaging unit 70 performs imaging at a third imaging timing when the tablet T reaches an imaging position directly below the third imaging unit 70 based on a detection signal (for example, a trigger signal) from the detection unit 30. A third image including the top surface of the tablet T is acquired, and the acquired third image is transmitted to the control device 90. The third imaging timing is the timing when the position of the tablet T on the transport belt 21 in the transport direction H1 overlaps with the center position of the imaging area of the third imaging section 70 in the transport direction H1. The third image is used to inspect the print pattern printed on the tablet T. As the third imaging section 70, for example, like the aforementioned imaging sections 40 and 50, various cameras having an imaging device such as a CCD or a CMOS are used. The third imaging unit 70 is electrically connected to the control device 90, and its driving is controlled by the control device 90. Illumination for imaging is also provided if necessary.

The recovery unit 80 is located downstream in the transport direction H1 from the position where the third imaging unit 70 is provided, and is provided at the downstream end of the transport unit 20 in the transport direction H1. The collecting section 80 is configured to separate and collect the tablets T that fall after being released from the holding by the conveying section 20 into defective and non-defective tablets. For example, defective products include unprinted tablets with cracks and chips, unprinted tablets with no cracks and stains (unprinted tablets with poor posture), and rejected tablets with cracks and no stains (defective tablets). be. A good product is a tablet that passes printing without any cracks, chips, or stains. Note that the conveyance section 20 releases the holding of the tablets T when each tablet T on the conveyance belt 21 reaches a predetermined position, for example, the downstream end of the conveyance section 20 in the conveyance direction H1.

The control device 90 includes a control section 91, a processing section 92, a storage section 93, and a correction section 94. Each part is composed of either or both of hardware (for example, an electric circuit) and software. The control section 91 is, for example, a microcomputer, and centrally controls each section. The processing unit 92 processes images using known image processing techniques. The storage unit 93 stores processing information, various programs, and the like. The control unit 91 controls the supply unit 10, the transport unit 20, each of the imaging units 40, 50, 70, the printing unit 60, etc. based on various information and various programs stored in the storage unit 93. Further, the control unit 91 receives detection information (for example, a detection signal) transmitted from the position detector 25 and the detection unit 30, and the processing unit 92 receives image information transmitted from each of the imaging units 40, 50, and 70. and so on.

The control unit 91 acquires information such as the movement amount (rotation amount) and speed of the conveyor belt 21 based on the detection information transmitted from the position detector 25 . Further, the control unit 91 determines the position of the tablet T in the conveying direction H1 (X direction) on the conveying belt 21 based on the detection information transmitted from the detecting unit 30, that is, the timing at which the tablet T on the conveying belt 21 is detected. The first position information (for example, trigger information) indicating this tablet position is generated and stored in the storage unit 93. Note that the control unit 91 and the detection unit 30 function as a first acquisition unit that acquires the position of the tablet T conveyed by the conveyance unit 20 in the conveyance direction H1.

Further, the control unit 91 controls the first imaging timing of the first imaging unit 40, the first imaging timing of the first imaging unit 40, The second imaging timing of the camera 51 of the second imaging unit 50, the printing timing of the inkjet head 61 of the printing unit 60, and the third imaging timing of the third imaging unit 70 are set, and timing information indicating these timings is set. It is generated and stored in the storage unit 93. The printing timing is the timing at which printing is started on the tablet T that has reached the printing position directly below the inkjet head 61. Note that the control unit 91 controls the first imaging timing for imaging the top surface of the tablet T transported by the transporting unit 20 and the second imaging timing for imaging the side surface of the tablet T transported by the transporting unit 20. It functions as a setting section that sets timing.

For example, as shown in FIG. 5, the timing at which the tablet T transported by the transport belt 21 reaches the detection position directly below the detection unit 30 (for example, the laser beam irradiation position) is set as reference 0, and the first imaging The timing of reaching the center position of the imaging area of the camera 51 of the second imaging unit 50 (first imaging timing) is 40 counts, and the timing of reaching the center position of the imaging area of the camera 51 of the second imaging unit 50 (second imaging timing) ) is 80 counts, the timing (printing timing) when the printing unit 60 reaches the printing position directly below the inkjet head 61 is 130 counts, and the timing (printing timing) when the printing unit 60 reaches the center position of the imaging area of the third imaging unit 70 ( The third imaging timing) is set to 180 counts. Then, information indicating those timings is generated and stored in the storage unit 93.

The processing unit 92 analyzes the image information transmitted from the first imaging unit 40, that is, the first image included in the image information, determines the center of the tablet T (for example, the center of gravity of the tablet), and calculates the center of the tablet T based on the determined center. The position of the tablet T on the conveyor belt 21 in the X direction, Y direction, and θ direction (see FIG. 2) is grasped, and second position information indicating this tablet position is generated and stored in the storage unit 93. Furthermore, when analyzing the first image described above, the processing unit 92 determines whether or not the tablet T has cracks or chips (presence or absence of cracks or stains), and determines whether the target tablet T has cracks or chips or stains. The first test information indicating whether or not the test information has the same is generated and stored in the storage unit 93. For example, the processing unit 92 performs a binarization process on the image of the top surface of the tablet T, grasps the density distribution, and if the density exceeds a threshold value (predetermined density), is judged to have cracks, chips, or stains. If the concentration is below the threshold value, it is determined that the upper surface of the target tablet T has no cracks, chips, or stains. Note that the processing unit 92 functions as a grasping unit (top face grasping unit) that grasps the top surface state of the tablet T conveyed by the conveyance unit 20 from the first image obtained by the first imaging unit 40.

Furthermore, when analyzing the first image described above, the processing unit 92 determines whether or not the tablet T has a poor posture (presence or absence of a poor posture), and determines whether or not the target tablet T has a poor posture. This information is also stored in the storage unit 93 as the first inspection information. Note that the processing unit 92 functions as a second acquisition unit that acquires the position of the tablet T transported by the transport unit 20 in the transport direction H1 from the first image obtained by the first imaging unit 40.

Here, the above-mentioned positions in the X direction and Y direction are, for example, positions in the XY coordinate system with respect to the center (reference position) of the imaging area of the first imaging unit 40. Further, the position in the θ direction is, for example, a position indicating the degree of rotation of the tablet T with respect to the center line in the Y direction of the imaging area of the first imaging unit 40. This position in the θ direction is detected when the tablet T has a directional shape, such as when the tablet T has a score line or when the tablet T is formed into an oval, oval, or square shape. be done. Further, the attitude of the tablet T is, for example, the inclination of the tablet T with respect to the suction surface of the conveyor belt 21.

Further, the processing unit 92 analyzes the image information transmitted from the second imaging unit 50, that is, the second image (individual images of the side surfaces of the tablet T by each prism 52a) included in the image information, and The storage unit 93 determines whether or not the tablet T has cracks or stains (presence or absence of cracks or stains), generates second inspection information indicating whether or not the target tablet T has cracks or stains, and generates second inspection information indicating whether or not the target tablet T has cracks or stains. Save to. For example, the processing unit 92 performs a binarization process on each image of the side surface of the tablet T by each prism 52a (for example, see FIG. If the density exceeds 100%, it is determined that the target tablet T has cracks, chips, or stains. If the concentration is below the threshold value, it is determined that the target tablet T has no cracks or stains. Note that the processing section 92 functions as a grasping section (side surface grasping section) that grasps the side surface state of the tablet T transported by the transporting section 20 from the second image obtained by the second imaging section 50.

Further, the processing unit 92 analyzes the image information transmitted from the third imaging unit 70, that is, the third image included in the image information, and prints the printing pattern (for example, characters or marks) printed on the tablet T. The position, shape, and size are acquired, and third inspection information indicating the print position, shape, and size of this print pattern is generated and stored in the storage unit 93.

By the way, the detection unit 30 is used to detect the tablet T conveyed by the conveyor belt 21 at a detection position directly below the detection unit 30 (for example, the laser beam irradiation position), and as described above, this detection signal (detection timing ) as a trigger signal to obtain the imaging timing of the first imaging unit 40, second imaging unit 50, and third imaging unit 70, in order to perform high-quality printing on the tablet T, especially the tablet T In the second imaging unit 50 that acquires a side image (second image) of the tablet T, a preset reference line (for example, a line in which the plurality of suction holes 21a are lined up) of the tablet T conveyed by the conveyor belt 21 is set. This is preferable in consideration of the deviation state. The reason is as follows.

For example, when the tablet T used in this embodiment is circular in plan view, the tablet T transported by the transport belt 21 is deviated from the reference line in a direction perpendicular to the transport direction in a horizontal plane. When the tablet T is conveyed at this time, the position of the tablet T in the conveyance direction at the output timing (detection timing) of the detection signal by the detection unit 30 in this misaligned state is different from the position of the tablet T in the conveyance direction at the detection timing when there is no misalignment. It will shift. Therefore, even if the tablet T is imaged at the imaging timing based on the detection timing, the center of the tablet T in the transport direction may deviate from the center of the imaging area of the camera of each imaging section 40, 50, 70 in the transport direction.

If the first imaging unit 40 and the third imaging unit 70 image the top surface of the tablet T, the depth of field of the camera is the height of the tablet T on the conveyor belt 21 (for example, several mm). The depth of field is set to correspond to the thickness of the image. Therefore, even if the top surface of the tablet T is imaged when the center of the tablet T in the transport direction is shifted from the center of the camera's imaging area in the transport direction, the thickness of the tablet T remains constant or almost constant, and the thickness of the tablet T remains constant or almost constant. The imaging distance to the top surface of the tablet T (distance between the camera and the subject) is also almost unchanged. Therefore, the camera focuses on the top surface of the tablet T, and the image obtained by capturing the top surface of the tablet T is not blurred.

On the other hand, in the case where the camera 51 of the second imaging unit 50 images the side surface of the tablet T, the center of the tablet T in the transport direction is shifted from the center of the imaging area of the camera 51 in the transport direction. When the side surface of the tablet T is imaged in this state, the imaging distance between the camera 51 and the side surface of the tablet T (distance between the camera and the subject) changes. For this reason, the camera 51 does not focus on the side surface of the tablet T, and the obtained image of the side surface of the tablet T becomes blurred. For example, in order to focus the camera 51 on the entire side surface of the tablet T, the depth of field of the camera 51 should be set to the radius of the tablet T plus the predicted positional shift amount of the tablet T (for example, 10 or more). It is necessary to set the depth of field to correspond to a depth of field (approximately several tens of millimeters). In other words, the depth of field of the camera 51 used in the second imaging unit 50 that images the side surface of the tablet T is greater than that of the camera used in the first imaging unit 40 and the third imaging unit 70 that image the top surface of the tablet T. It will also be set in depth. Therefore, if you increase the F number to deepen the depth of field, you will need to slow down the shutter speed. For this reason, there is a limit to obtaining a clear image of the side surface of the tablet T as it moves during transportation without any motion blur, and it is difficult to sufficiently grasp cracks, chips, stains, etc. on the tablet T.

Therefore, in this embodiment, when acquiring the second image using the camera 51, the amount of positional deviation of the tablet T with respect to the camera 51 can be eliminated, the depth of field of the camera 51 can be made shallow, and the shutter speed can be made faster. This configuration allows the side surface of the moving tablet T to be clearly imaged. This will be explained in detail below.

The correction unit 94 corrects the first position information stored in the storage unit 93 (the position of the tablet T in the transport direction H1 on the transport belt 21) based on the second position information stored in the storage unit 93 (the position of the tablet T in the transport direction H1 on the transport belt 21). Various timings (second imaging timing, printing timing, third imaging timing) are corrected based on the position of the tablet T in the transport direction H1 in . When the tablet T transported by the transport belt 21 is located at the detection position directly below the detection unit 30 (for example, the laser beam irradiation position), the position of the tablet T on the transport belt 21 in the transport direction H1 is grasped, and the first Although various timings are set based on the positional information, these timings are corrected based on the second positional information. Various timings are managed by time or distance (for example, distance determined by the position detector 25). Note that although it is not necessarily necessary to correct the printing timing other than the second imaging timing or the third imaging timing, it is desirable to correct the printing timing or the third imaging timing in order to improve printing accuracy or inspection accuracy. .

In FIG. 5 shown above, when 40 counts have elapsed after the tablet T transported by the transport belt 21 reaches the detection position directly below the detection section 30, the first imaging section 40 captures an image. If it is determined from the first image obtained by the first imaging unit 40 that the position of the tablet T in the transport direction H1 on the transport belt 21 is 45 counts, and that the tablet T has moved forward by 5 counts. , the second imaging timing of the camera 51 of the second imaging unit 50 is corrected from 80 to 75 (=80-5), and the printing timing of the inkjet head 61 of the printing unit 60 is corrected from 130 to 125 (=130-5). 5), and the third imaging timing of the third imaging unit 70 is corrected from 180 to 175 (=180-5). Thereby, when the tablet T transported by the transport unit 20 reaches the center position of the imaging area of the camera 51 of the second imaging unit 50, it becomes possible for the camera 51 to image the side surface of the tablet T, and also, It becomes possible for the inkjet head 61 to start printing when the printing position directly below the inkjet head 61 of the printing unit 60 is reached, and when the center position of the imaging area of the third imaging unit 70 is reached, the third The imaging unit 70 can image the top surface of the tablet T.

The control unit 91 determines whether or not to set the printing conditions for the tablet T based on the first inspection information and the second inspection information stored in the storage unit 93, and when it is determined that the printing conditions are to be set, Printing conditions for the tablet T are set based on the second position information stored in the storage unit 93. For example, when the control unit 91 determines that the first inspection information indicates that the target tablet T has a poor posture, or the first inspection information or the second inspection information If it is determined that the tablet T has cracks, chips, or stains, printing conditions for that tablet T are not set, and printing for the target tablet T is prohibited. Further, the control unit 91 determines that the first inspection information indicates that the target tablet T does not have poor posture, and the control unit 91 determines that the target tablet T does not have a posture defect, and both the first inspection information and the second inspection information When it is determined that T has no cracks, chips, or stains, the inkjet head 61 selects the target tablet based on the Y-direction position information and printing pattern of the tablet T included in the second position information. Determining the range of the nozzle 61a (used nozzle range) used for printing T, and determining the ejection timing for the tablet T based on the above-mentioned printing timing (timing to start printing for the tablet T) Then, print conditions are set and saved in the storage section 93. Note that when the tablet T is in a form with directionality, the control unit 91 also uses the position information of the tablet T in the θ direction included in the second position information, and prints in correspondence with the position of the tablet T in the θ direction. Set conditions.

The control unit 91 also determines whether or not the print pattern is printed at a predetermined position on the tablet T in a predetermined shape and size, based on the third inspection information stored in the storage unit 93. It is determined whether or not the tablet T has been printed normally (printing status inspection), and printing quality information indicating the quality of printing of the tablet T is generated and stored in the storage unit 93. For example, in determining the print position, shape, and size of a print pattern, the control unit 91 registers the print pattern used for printing in the storage unit 93 as a test print pattern, and compares the test print pattern with the actual print pattern. Compare the printing pattern on the printed tablet T (printing pattern printed on the tablet T) to determine whether the printing pattern was correctly printed on the printed tablet T printed by the inkjet head 61. to decide.

Here, the aforementioned various information (for example, first position information, timing information, second position information, first inspection information, second inspection information, third inspection information, print quality information, etc.) It is generated for each tablet T transported by the transport belt 21 and stored in the storage unit 93, but when the target tablet T is collected by the collection unit 80, for example, When a predetermined time (for example, several seconds) has elapsed after falling from the edge, it is deleted from the storage unit 93. However, if it is needed in a later process, etc., it is also possible to leave various information for each tablet T without erasing it.

(Printing process)
Next, the printing process (printing process) performed by the above-mentioned tablet printing apparatus 1 will be described with reference to FIG. 6. Various information such as data required for printing (for example, print data including a print pattern and the print position of the print pattern on the tablet T, movement speed data of the conveyor belt 21, etc.) is stored in the storage unit 93 of the control device 90. It is stored in advance. Note that when the tablet printing device 1 starts the printing process, the motor 24 is driven, and the conveyor belt 21 rotates in the conveyance direction H1 as the drive pulley 22 and the driven pulley 23 are rotated by the motor 24.

As shown in FIG. 6, in step S1, while the conveyor belt 21 is rotating in the conveyance direction H1, the tablets T are sequentially supplied from the hopper 11 to the chute 12, are arranged in a line by the chute 12, and are placed on the conveyor belt 21. The tablets T are supplied on the conveyor belt 21 at random rather than at regular intervals, and are conveyed in a line on the conveyor belt 21 at a predetermined moving speed.

In step S2, the tablet T on the conveyor belt 21 is detected by the detection unit 30. Specifically, the tablet T on the conveyor belt 21 is detected by the detection unit 30 at the timing when it reaches the detection position directly below the detection unit 30 (for example, the laser beam irradiation position), and based on the timing at which the tablet T is detected, The position of the tablet T in the transport direction H1 (X direction) on the transport belt 21 is grasped by the control unit 91. Then, first position information indicating the tablet position is generated by the control unit 91 and stored in the storage unit 93.

In step S3, various timings (first imaging timing, second imaging timing, printing timing (third imaging timing) is set by the control unit 91. Timing information indicating these timings is generated by the control section 91 and stored in the storage section 93.

In step S4, the tablet T on the conveyor belt 21 is imaged by the first imaging section 40. Specifically, the tablet T on the conveyor belt 21 is imaged by the imaging unit 40 at the first imaging timing when the tablet T reaches the imaging position directly below the first imaging unit 40 based on timing information stored in the storage unit 93. , the first image obtained by the first imaging unit 40 is transmitted to the control device 90.

In step S5, the processing unit 92 grasps the position, cracks, chips, dirt, and posture of the tablet T on the conveyor belt 21. Specifically, the first image transmitted from the first imaging unit 40 is analyzed by the processing unit 92, and second position information of the tablet T (for example, position information in the X direction, Y direction, and θ direction) is generated. , are stored in the storage unit 93. Furthermore, through the above-mentioned image analysis, the processing unit 92 determines whether the tablet T has cracks, chips or stains, and whether the tablet T has a poor posture, and stores them in the storage unit 93 as first inspection information. Ru.

In step S6, based on the second position information stored in the storage unit 93, the correction unit 94 determines whether or not there is a positional shift of the tablet T on the conveyance belt 21 in the conveyance direction H1 (X direction). . Specifically, based on the position information in the X direction included in the second position information of the tablet T, the position of the tablet T in the transport direction H1 on the transport belt 21 and the image taken by the first imaging unit 40 are determined in the first image. The amount of deviation from the center position of the area in the transport direction H1 is calculated by the correction unit 94, and if the amount of deviation is 0 (zero), it is determined that there is no positional deviation of the tablet T, and if the amount of deviation is not 0, It is determined that there is a positional shift of the tablet T. If it is determined that there is a positional shift in the transport direction H1 of the tablet T on the transport belt 21 (YES), the process proceeds to step S7. On the other hand, if it is determined that there is no positional shift in the transport direction H1 of the tablet T on the transport belt 21 (NO), the process proceeds to step S8.

In step S7, various timings (second imaging timing, print timing, third imaging timing) are corrected by the correction unit 94. Specifically, the timing information stored in the storage unit 93, that is, the second imaging timing, print timing, and third imaging timing, is corrected based on the shift amount calculated in step S5 described above. In other words, the second imaging timing is the timing when the position of the tablet T in the transport direction H1 on the transport belt 21 overlaps with the center position of the imaging area of the camera 51 in the transport direction H1 (the tablet T is (timing when the image capture position directly below is reached). The printing timing is the timing when the position of the tablet T in the transport direction H1 on the transport belt 21 overlaps the printing position directly below the inkjet head 61 (the timing when the tablet T reaches the printing position directly below the inkjet head 61 of the printing unit 60 ). The third imaging timing is the timing when the position of the tablet T in the transport direction H1 on the transport belt 21 overlaps the center position of the imaging area of the third imaging section 70 in the transport direction H1 (the tablet T is The timing is corrected so that the timing of reaching the imaging position immediately below is corrected.

In step S8, the tablet T on the conveyor belt 21 is imaged by the second imaging section 50. Specifically, the tablet T on the conveyor belt 21 is captured at the second imaging timing when the tablet T on the conveyor belt 21 reaches the imaging position directly below the second imaging unit 50 based on the corrected timing information stored in the storage unit 93. An image is captured by the imaging unit 50, and a second image obtained by the imaging by the second imaging unit 50 is transmitted to the control device 90.

In step S9, the processing unit 92 detects cracks, chips, or stains on the tablets T on the conveyor belt 21. Specifically, the second image transmitted from the second imaging section 50 is analyzed by the processing section 92, and the processing section 92 also determines whether or not the tablet T has cracks, chips, or dirt. Second inspection information indicating whether or not there is chipping or staining is stored in the storage unit 93.

In step S<b>10 , the control unit 91 determines from the first inspection information and second inspection information stored in the storage unit 93 whether or not there is poor posture, cracks, chips, or stains. If it is determined that there is no poor posture, cracks, chips, or stains (NO), the process proceeds to step S11, and printing on the target tablet T is permitted. On the other hand, if it is determined that there is poor posture, cracking, chipping, or staining (YES), the process proceeds to step S16, and printing on the target tablet T is prohibited.

In step S11, printing conditions are set by the control unit 91 based on the second position information and the print pattern stored in the storage unit 93. Specifically, the printing conditions for the tablet T are set by the control unit 91 based on the second position information and the printing pattern stored in the storage unit 93, and are stored in the storage unit 93. For example, the range of the nozzle 61a used for printing the target tablet T in the inkjet head 61 is determined based on the Y-direction position information and printing pattern of the tablet T included in the second position information, and Based on the print timing (timing to start printing on the tablet T), the ejection timing for the tablet T is determined, and the printing conditions are set and stored in the storage unit 93.

In step S12, printing is performed based on the printing conditions stored in the storage section 93. That is, the control unit 91 controls the inkjet head 61 of the printing unit 60 to print in a predetermined printing pattern. Specifically, the tablet T on the conveyor belt 21 that has passed below the second imaging section 50 is moved to a printing position directly below the inkjet head 61 of the printing section 60 based on the corrected timing information stored in the storage section 93. At the printing timing reached, printing is performed by the inkjet head 61 based on the above-mentioned printing conditions. In the inkjet head 61, ink is suitably ejected from each nozzle 61a, and a printing pattern (for example, alphabets, katakana, numbers, symbols, figures) is printed on the printing surface, which is the upper surface of the tablet T. The ink applied to this tablet T dries quickly. Note that the ink may be dried using a drying section (not shown) that performs drying using gas or heat.

In step S13, the printed tablets T on the conveyor belt 21 are imaged by the third imaging section 70. Specifically, the printed tablets T on the conveyor belt 21 are moved at the third imaging timing when they reach the imaging position directly below the third imaging unit 70 based on the corrected timing information stored in the storage unit 93. An image is captured by the third imaging unit 70, and a third image obtained by the imaging by the third imaging unit 70 is transmitted to the control device 90.

In step S13, the processing unit 92 acquires information regarding the printed pattern printed on the tablet T, that is, the printing position, shape, and size of the printed pattern. Specifically, the third image transmitted from the third imaging section 70 is analyzed by the processing section 92, and third inspection information indicating the printing position, shape, and size of the printed pattern on the tablet T is generated. , are stored in the storage unit 93.

In step S15, a printing state inspection is performed based on the third inspection information stored in the storage section 93. Specifically, the control unit 91 determines whether or not the printing pattern has been correctly printed on the tablet T based on the above-mentioned third inspection information regarding the printing position, shape, and size stored in the storage unit 93. Printing quality information indicating the quality of printing of T is generated and stored in the storage unit 93. For example, in a print condition inspection, the print pattern used for printing is stored in the storage unit 93 as a print pattern for inspection, and non-defective information regarding the predetermined printing position, shape, and size of the print pattern for inspection is stored in the storage unit 93. The third inspection information regarding the printing position, shape, and size of the saved actual printed printing pattern is compared, and it is determined whether the printing pattern has been correctly printed on the tablet T (pass or fail). Ru.

In step S16, the tablet T is collected by the collection unit 80. Specifically, when the tablet T after inspection is located at the downstream end of the conveyor belt 21 as the conveyor belt 21 moves, it is released from being held by the conveyor belt 21, falls from the conveyor belt 21, and is collected. 80. At this time, good tablets (printed tablets with no cracks or stains) T fall as they are and are collected by the collection unit 80, but defective tablets (for example, unprinted tablets with cracks or stains), The unprinted tablets (unprinted tablets with no cracks, chips, or stains) or rejected tablets (printed tablets with no cracks, chips, or stains) are removed by blowing gas (for example, air) while falling from the conveyor belt 21. Note that the tablets T removed by the gas spraying are collected by another collection container (not shown) provided next to the collection unit 80, for example.

According to such a printing process, the first imaging timing for capturing an image of the upper surface of the tablet T transported by the transport unit 20 based on the position of the tablet T transported by the transport unit 20 in the transport direction H1; A second imaging timing for imaging the side surface of the tablet T transported by the transport unit 20 is set. Based on the set first imaging timing, the top surface of the tablet T transported by the transport unit 20 is imaged by the first imaging unit 40, and from the first image obtained by the first imaging unit 40, the top surface of the tablet T transported by the transport unit 20 is The position of the tablet T transported by the unit 20 in the transport direction H1 is acquired. Then, the above-mentioned second imaging timing is corrected based on the acquired position of the tablet T in the transport direction H1, and at the corrected second imaging timing, the side surface of the tablet T transported by the transport unit 20 is The condition of the side surface of the tablet T (for example, whether there are cracks, chips, or stains) can be grasped from the second image obtained by the second image pickup section 50 .

In the correction of the second imaging timing described above, the second imaging timing is based on the position of the tablet T in the transport direction H1 obtained from the first image (image including the top surface of the tablet T) by the first imaging unit 40. Based on this, the timing is corrected so that the position of the tablet T transported by the transport section 20 in the transport direction H1 overlaps with the center position of the imaging area of the second imaging section 50 in the transport direction H1. As a result, the tablet T transported by the transport section 20 is transported at a timing when the position of the tablet T transported by the transport section 20 in the transport direction H1 overlaps with the center position of the imaging area of the second imaging section 50 in the transport direction H1. , is imaged by the second imaging unit 50. In this way, the side surface of the tablet T can be imaged without any displacement in the transport direction H1 of the tablet T with respect to the center position of the imaging area of the second imaging unit 50. Therefore, it is possible to set the depth of field without considering the positional deviation of the tablet T in the transport direction H1, or even if it is taken into account, the amount is small, and the depth of field can be made shallow. I can do it. As a result, since it becomes possible to increase the shutter speed, it is possible to clearly image the side surface of the tablet T that is being transported and moving. Since the side surface of the moving tablet T can be clearly imaged, smaller cracks, chips or stains can be detected, and the inspection accuracy of the side surface of the tablet T can be improved. In addition, since the depth of field can be made shallow, the second imaging section 50 can be made into an imaging section with a shallow depth of field, for example, by decreasing the F number, and by increasing the F number, it is possible to Compared to an imaging section with a deep depth of field, the brightness of the illumination required for taking pictures can be reduced.

As described above, according to the embodiment, it is possible to eliminate positional deviation in the transport direction H1 of the tablet T with respect to the center position of the imaging area of the second imaging unit 50, and to image the side surface of the tablet T. Since the depth of field can be made shallow and the shutter speed can be made faster, it is possible to clearly image the side surface of the tablet T that is being transported and moving. Therefore, it becomes possible to detect smaller cracks, chips, or stains, and the accuracy of inspecting the side surface of the tablet T can be improved. By improving the inspection accuracy, it becomes possible to prohibit and eliminate printing even for tablets T with small cracks, chips, or stains, for example, making it possible to perform high-quality printing.

Note that although a tablet with substantially flat upper and lower surfaces is used as the tablet T, the present invention is not limited to this, and for example, a tablet having a score line (recessed portion) may be used. When using a tablet with a score line, it is necessary to distinguish whether the black triangle B1 described above is due to cracks, chips or stains, or is due to the score line. In the images of all sides of the tablet T taken by each prism 52a, the faces, positions, and number of black triangles B1 are different. Therefore, it is possible to recognize the black triangle B1 caused by the secant line, identify the presence or absence of the secant line, and further specify the plane and angle on which the secant line is formed. For example, as shown in FIG. 7, if black triangles B1 exist at two positions facing each other across the center of the tablet T, it is determined that these black triangles B1 are created by a straight line dividing line. can do. Moreover, when the black triangle B1 exists on the upper surface M2, it can be seen that there is a score line on the upper surface of the tablet T. On the other hand, if the black triangle B1 does not exist at two positions facing each other across the center of the tablet T, it is determined that the black triangle B1 is not a straight dividing line but is caused by a crack, a chip, or a stain. I can do it.

<Other embodiments>
In the above description, printing is performed on the tablet T using the tablet printing apparatus 1 (tablet printing method) according to the embodiment described above. This can also be expressed as printing on the tablet T using the tablet printing device 1 (tablet printing method) according to the embodiment described above, and producing a printed tablet T. That is, the tablet printing device 1 can be translated into a tablet manufacturing device, and the tablet printing method can be translated into a tablet manufacturing method.

Furthermore, in the above description, an example was given in which images of all sides of the tablet T (outer circumferential surface for one circumference) are used for processing by the second imaging unit 50; however, the present invention is not limited to this. The image of the top surface of the tablet T may be used for processing together with the image of the tablet T. The second image obtained by the second imaging unit 50 includes an image of the top surface of the tablet T. The positional information of the tablet T on the conveyor belt 21 (the position of the tablet T in the X direction, Y direction, and θ direction) is obtained from the image of the top surface of the tablet T, and the printing timing of the printing unit 60 is determined based on this positional information. Alternatively, the imaging timing of the third imaging unit 70 may be corrected. In addition, when the tablet T is a tablet having a score line, the image of all sides or the top surface of the tablet T is used for processing by the second imaging unit 50, and a plurality of black triangles B1 based on the score line are formed (see FIG. 7). ), the positional information of the tablet T on the conveyor belt 21 (the position of the tablet T in the X direction, Y direction, and θ direction) is acquired, and based on this positional information, the printing timing of the printing section 60 and the third imaging section 70 are adjusted. It is also possible to correct the imaging timing.

Furthermore, in the above description, the correction unit 94 corrects various timings (second imaging timing, print timing, third imaging timing) set by the control unit 91 based on the second position information. Although this is an example, the present invention is not limited to this. For example, the correction unit 94 may not be provided and various timings may be set based only on the second position information.

Furthermore, in the above description, it is assumed that the first imaging section 40, the second imaging section 50, and the third imaging section 70 are each still image cameras, and the explanation focuses on the imaging timing of each camera. did. However, for example, if the camera is for moving images and the processing unit 92 appropriately captures images from the camera and processes the images based on instructions from the control unit 91, the above-described image capture timing may be read as capture timing. In any case, the control device 90 causes the first imaging section 40 to detect the tablet T based on the position in the transport direction of the tablet T acquired by the first acquisition section which includes the control section 91 and the detection section 30. The position in the transport direction of the tablet T acquired by the second acquisition unit which images the top surface and includes the processing unit 92, or the position in the transport direction of the tablet T acquired by the first and second acquisition units. Based on the position, the second imaging unit 50 is caused to image the side surface of the tablet T.

Further, in the above description, the light guide member 52 is provided to capture images of all sides of the tablet T, but the invention is not limited to this. For example, the light guide member 52 is not provided and multiple cameras 51 Alternatively, all sides of the tablet T may be imaged.

Further, in the above description, the use of a plurality of prisms 52a as the light guide member 52 was illustrated, but the present invention is not limited to this, and for example, a mirror or an optical fiber may be used.

Further, in the above description, the light guide member 52 is configured by six prisms 52a, but the number is not limited to this, and the number of prisms 52a may be, for example, three, four, five or more. It may be eight, odd or even numbers, and is not limited. Further, although each prism 52a is arranged in a hexagonal ring shape, the present invention is not limited to this. For example, the prisms 52a may be arranged in a polygonal ring shape such as a triangle, a quadrangle, or a pentagon to an octagon. The shape is not limited. Further, one prism 52a may be used as the light guide member 52, and the one prism 52a may be formed in an annular shape such as a circle or an ellipse. Note that it is also possible to integrate the respective prisms 52a described above.

Furthermore, in the above description, the tablet T to be printed is circular in plan view, and the top and bottom surfaces of the tablet T are flat. Alternatively, spindle-shaped, perfectly circular, disc-shaped, lens-shaped, triangular, or elliptical tablets may be used. Note that the tablet thickness is not constant, such as when the shape of the tablet T is a spindle shape or a lens shape, but in this case, the first imaging section 40, the second imaging section 50, and the third imaging section 70 , each having a depth of field that focuses on the top surface of the tablet T is preferable.

Furthermore, in the above description, the tablets T are conveyed in one row, but the number of rows is not limited to this, and may be two, three, or four or more, and is not particularly limited. The number of conveyor belts 21 may be two or more, and is not particularly limited. Furthermore, the number of inkjet heads 61 may be two or more, and is not particularly limited.

Further, in the above description, a print head in which the nozzles 61a are arranged in one row is illustrated as an example of the inkjet head 61, but the present invention is not limited to this. For example, a print head in which the nozzles 61a are arranged in multiple rows may be used. good. Alternatively, a plurality of inkjet heads 61 may be used in a horizontal plane in a direction perpendicular to the transport direction H1.

Further, in the above description, the inkjet head 61 is provided so that the direction in which the nozzles 61a are lined up is perpendicular to the transport direction H1 in the horizontal plane, but the invention is not limited to this. For example, the nozzles 61a They may be provided so that the direction in which they are lined up is a direction that intersects the conveyance direction H1 in a horizontal plane.

In addition, in the above description, printing on one side of the tablet T was exemplified, but the invention is not limited to this. 50, the printing section 60 and the third imaging section 70 are made into one unit, and the units are stacked one on top of the other, and the tablet T printed in the upper conveyance section 20 is reversed and transferred to the lower conveyance section 20. Upon delivery, both sides of the tablet T may be printed.

Furthermore, in the above description, the tablets T are supplied on the conveyor belt 21 at random rather than at regular intervals, but the present invention is not limited to this, and they may be supplied at regular intervals. Furthermore, in the above description, the tablets T are sucked and held by the suction holes 21a formed on the conveyor belt 21, but the invention is not limited to this. Alternatively, it may be held on the conveyor belt 21 by its own weight and conveyed.

Here, the above-mentioned tablets can include tablets used for medicine, for eating and drinking, for cleaning, for industrial purposes, and for aromatic purposes. In addition, tablets include plain tablets, sugar-coated tablets, film-coated tablets, enteric-coated tablets, gelatin-encapsulated tablets, multilayer tablets, and dry-coated tablets, as well as various types of capsule tablets such as hard capsules and soft capsules. can be included in Furthermore, tablets can have various shapes such as a disc, a lens, a triangle, and an ellipse. Furthermore, when the tablet to be printed is for pharmaceutical use or food or drink use, 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.

Although several embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included within the scope and gist of the invention, as well as within the scope of the invention described in the claims and its equivalents.

1 Tablet printing device 20 Transport section 30 Detection section 40 First imaging section 50 Second imaging section 61 Inkjet head 91 Control section 92 Processing section 94 Correction section T Tablet

Claims (5)

a transport unit that transports tablets to be printed;
a first acquisition unit that acquires a position in the conveyance direction of the tablet conveyed by the conveyance unit;
The upper surface of the tablet, which is provided downstream of the first acquisition unit in the conveyance direction of the tablet, and is conveyed by the conveyance unit based on the position of the tablet in the conveyance direction acquired by the first acquisition unit. a first imaging unit that images the
a second acquisition unit that acquires the position in the conveyance direction of the tablet conveyed by the conveyance unit from an image including the top surface of the tablet obtained by the first imaging unit;
A side surface of the tablet that is provided downstream of the first imaging unit in the transport direction of the tablet and that is transported by the transport unit based on the position of the tablet in the transport direction that is acquired by the second acquisition unit. a second imaging unit that images the
The second imaging unit is provided downstream of the tablet in the transport direction, and prints on the tablet transported by the transport unit based on the position of the tablet in the transport direction acquired by the second acquisition unit. a print head that performs
Tablet printing device with Based on the position of the tablet in the transport direction acquired by the first acquisition unit, a first imaging timing for imaging the top surface of the tablet transported by the transport unit, and a first imaging timing for imaging the top surface of the tablet transported by the transport unit a setting unit that sets a second imaging timing for imaging a side surface of the tablet and a printing timing for printing by the print head on the tablet transported by the transport unit ;
a correction unit that corrects the second imaging timing and the printing timing based on the position of the tablet in the transport direction acquired by the second acquisition unit;
has
The second imaging unit images the side surface of the tablet transported by the transport unit at the second imaging timing corrected by the correction unit , and at the printing timing corrected by the correction unit, The tablet printing device according to claim 1 , wherein the print head prints on the tablets transported by the transport section . The correction unit corrects the second imaging timing to a timing at which a position in the transport direction of the tablet transported by the transport unit overlaps a center position in the transport direction of an imaging area of the second imaging unit. ,
The tablet printing apparatus according to claim 2 , wherein the correction section corrects the printing timing to a timing at which a position of the center of the tablet transported by the transport section in the transport direction overlaps directly below the print head . a grasping unit that grasps the state of the side surface of the tablet conveyed by the conveyance unit from an image including the side surface of the tablet obtained by the second imaging unit;
It is determined whether the side condition of the tablet grasped by the grasping unit is acceptable, and when it is determined that the side condition of the tablet is acceptable, the printing head is caused to execute the printing, and the side condition of the tablet is determined to be acceptable. a control unit that causes the print head to prohibit the printing when it is determined that the side surface condition is unacceptable;
The tablet printing device according to any one of claims 1 to 3, having the following. a step of conveying the tablet to be printed by a conveying section;
a step of acquiring, by a first acquisition unit, the position in the conveyance direction of the tablet conveyed by the conveyance unit;
Based on the position of the tablet in the transport direction acquired by the first acquisition unit, a first imaging timing for imaging the top surface of the tablet transported by the transport unit, and a first imaging timing for imaging the top surface of the tablet transported by the transport unit a step of setting a second imaging timing for imaging the side surface of the tablet by a setting unit;
a step of imaging the top surface of the tablet transported by the transporting unit with a first imaging unit at the first imaging timing set by the setting unit;
a step of acquiring, by a second acquisition unit, the position of the tablet in the conveyance direction of the tablet conveyed by the conveyance unit from an image including the top surface of the tablet obtained by the first imaging unit;
Correcting the second imaging timing by a correction unit based on the position of the tablet in the transport direction acquired by the second acquisition unit;
a step of imaging a side surface of the tablet transported by the transport unit with a second imaging unit at the second imaging timing corrected by the correction unit;
a printing step of printing on the tablet conveyed by the conveyance unit based on the position of the tablet in the conveyance direction acquired by the second acquisition unit;
has
In the correcting step, the second imaging timing is corrected to a timing at which a position in the transport direction of the tablet transported by the transport unit overlaps a center position in the transport direction of an imaging area of the second imaging unit. Tablet manufacturing method.

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