Capsule Marking Device and Method

Abstract

A capsule marking device 1 comprises: a conveyance unit 2 that conveys a capsule C along a conveyance path 2a; a first imaging unit 30 that images the capsule C being conveyed, thus acquiring first imaging data; a marking unit 40 that marks the capsule C being conveyed; and a control unit that sets a marking area on the capsule C on the basis of the first imaging data and forms a marking pattern in the marking area by controlling operation of the marking unit 40. The capsule marking device 1 further comprises: a separation unit 60 that selectively separates the capsule C, while same is being conveyed, from the conveyance path 2a. By controlling operation of the separation unit 60, the control unit causes the capsule C to be separated without formation of the marking pattern when the size of a seam in the marking area in the first imaging data is greater than or equal to a predetermined criterion.

Description

Technical Field

[0001] The present invention relates to a capsule marking device and method, and more particularly to a capsule marking device and method suitable for marking edible capsules such as soft capsules and hard capsules.

Background Art

[0002] As a device capable of marking a capsule, for example, a configuration disclosed in Patent Document 1 is known. This device includes a conveying means for conveying an edible object such as a tablet or a capsule, a detecting means for imaging the edible object and acquiring direction data, a marking means for forming a marking pattern on the edible object, and a marking inspection means for inspecting the marking pattern formed on the edible object. Since this device can perform marking based on the direction data of the edible object, when the edible object is a scored tablet, marking can be performed along the score line so as not to intersect the score line.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, for an edible object made of a capsule, there may be a seam (joint) on the surface. For example, in the case of a soft capsule, the heat seal portion between the films formed by a rotary method appears as a seam. This seam does not always appear in the marking area like the score line of a scored tablet, and when it does not overlap the marking area, it does not affect the visibility of the marking. However, when the seam overlaps the marking area, it is difficult to perform marking while avoiding the seam, and there is a risk that the visibility of the marking will decrease.

[0005] Therefore, an object of the present invention is to provide a capsule marking apparatus and method capable of efficiently performing marking with good visibility.

Means for Solving the Problems

[0006] The above object of the present invention is achieved by a capsule marking apparatus including a conveyance unit that conveys capsules along a conveyance path, a first imaging unit that images the conveyed capsules to obtain first imaging data, a marking unit that performs marking on the conveyed capsules, and a control unit that sets a marking area on the capsules based on the first imaging data and forms a marking pattern in the marking area by controlling the operation of the marking unit, the capsule marking apparatus further including a detachment unit that selectively detaches the capsules being conveyed from the conveyance path, wherein the control unit detaches, without forming a marking pattern, the capsules in which the size of the seam in the marking area in the first imaging data is equal to or greater than a predetermined standard by controlling the operation of the detachment unit.

[0007] Preferably, this capsule marking apparatus further includes a second imaging unit that images the capsules on which the marking pattern is formed to obtain second imaging data, and preferably, the control unit determines the quality of the marking pattern based on the difference data between the first image data and the second image data when the size of the seam in the marking area in the first imaging data is less than a predetermined standard.

[0008] The conveying path is preferably formed linearly. The first imaging unit preferably includes a camera arranged such that the imaging direction is orthogonal to the conveying path, a reflection illumination unit arranged on the same side of the conveying path as the camera, and a transmission illumination unit arranged on the opposite side of the conveying path from the camera. In this configuration, the reflection illumination unit preferably includes a ring illumination, a first polarizing plate arranged between the ring illumination and the conveying path, and a second polarizing plate arranged between the camera and the conveying path and having a polarization axis orthogonal to the polarization axis of the first polarizing plate. It is also preferably provided with a polarizing plate driving unit for moving the second polarizing plate.

[0009] The control unit preferably sets the marking area based on the posture of the capsule identified by the contour of the capsule in the first imaging data.

[0010] The marking unit preferably performs marking by irradiating a CO2 laser.

[0011] Also, the object of the present invention is achieved by a capsule marking method including: a first imaging step of imaging a capsule conveyed on a conveying path with a first imaging unit to obtain first imaging data, and setting a marking area on the capsule based on the first imaging data; a separation step of separating a capsule having a seam size within the marking area greater than or equal to a predetermined standard from the conveying path; and a marking step of forming a marking pattern in the marking area of the capsule conveyed through the separation step. In the marking step, when the size of the seam within the marking area in the first imaging data is less than the predetermined standard, the marking pattern can be formed while avoiding the seam.

Advantages of the Invention

[0012] According to the present invention, it is possible to provide a capsule marking device and method capable of efficiently performing marking with good visibility.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Mode for Carrying Out the Invention

[0014] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a schematic front view of a capsule marking device according to an embodiment of the present invention. As shown in FIG. 1, the capsule marking device 1 includes a conveyance unit 2, a first imaging unit 30, a marking unit 40, a second imaging unit 50, and a separation unit 60.

[0015] FIG. 2 is a sectional view taken along the line A-A of FIG. 1, and FIG. 3 is a plan view of the main part of the conveyance unit 2 shown in FIG. 1. As shown in FIGS. 1 to 3, the conveyance unit 2 includes a first conveyance device 10 and a second conveyance device 20. The first conveyance device 10 includes a hat-shaped disk 11, an intermediate ring 12 that houses the disk 11, and a rotating ring 13 that houses the intermediate ring 12.

[0016] While the rotation axes 11a and 13a of the disk 11 and the rotating ring 13 extend in the vertical direction, the rotation axis 12a of the intermediate ring 12 is arranged to be slightly inclined with respect to the rotation axes 11a and 13a. The rotation axes 11a, 12a, and 13a are each connected via a speed reducer 11b, 12b, and 13b to a drive source (not shown) such as a motor provided individually, and the disk 11, the intermediate ring 12, and the rotating ring 13 can be rotationally driven independently of each other.

[0017] On the upper parts of the intermediate ring 12 and the rotating ring 13, conveying surfaces 12c and 13c are respectively formed along the circumferential direction. The conveying surface 13c of the rotating ring 13 is covered by a ring-shaped protrusion 13d on the radially outer side.

[0018] The second conveying device 20 includes a first pulley 21 and a second pulley 22 whose respective rotation axes 21a and 22a are arranged horizontally, an endless belt body 23 wound around the first pulley 21 and the second pulley 22, and a guide member 24 arranged along the conveying direction of the belt body 23. The diameter of the second pulley 22 is smaller than the diameter of the first pulley 21. The straight portion of the belt body 23 located between the first pulley 21 and the second pulley 22 is arranged horizontally above the first pulley 21 and the second pulley 22 to form a linear conveying path 2a, while being inclined below the first pulley 21 and the second pulley 22.

[0019] As shown in FIG. 2, the first pulley 21 is configured by connecting two disks 21b and 21c to each other with a space therebetween by a rotation axis 21a. Similarly, the second pulley 22 also includes two disks connected to each other with a space therebetween by a rotation axis 22a. In the present embodiment, the first pulley 21 is used as a drive pulley connected to a drive motor (not shown), and the second pulley 22 is used as a driven pulley, but the first pulley 21 may be used as a driven pulley and the second pulley 22 may be used as a drive pulley.

[0020] The belt body 23 includes two belt-shaped conveying belts 23a and 23b, and each conveying belt 23a, 23b is wound around the disks 21b, 21c of the first pulley 21 respectively. An opening 23c formed of a fine gap is formed over the entire circumference of the belt body 23 between the two conveying belts 23a, 23b. The conveying belts 23a, 23b can be formed of a flat belt made of a soft material such as silicon rubber, for example, but a V-belt, a toothed belt, or the like may also be used.

[0021] As shown in FIG. 1, the guide member 24 includes a straight portion 24a disposed immediately below the vicinity of the belt body 23 that extends horizontally along the conveying path 2a between the first pulley 21 and the second pulley 22, and arc portions 24b, 24c provided on both sides of the straight portion 24a in the conveying direction respectively. Each arc portion 24b, 24c is inserted between the two disks provided on the first pulley 21 and the second pulley 22, and is formed to be curved in an arc shape along the belt body 23 wound around the first pulley 21 and the second pulley 22.

[0022] As shown in FIG. 2, the guide member 24 is formed in a hollow cylindrical shape, and a slit-shaped suction portion 25 is formed along the opening 23c at a portion where the guide member 24 faces the opening 23c of the belt body 23. The inside of the guide member 24 can be depressurized by the operation of a vacuum pump (not shown), and by sucking the capsule C to the suction portion 25 through the opening 23c of the belt body 23, the capsule C can be conveyed together with the belt body 23 in a state of being adsorbed to the belt body 23. The opening 23c of the belt body 23 in the present embodiment is continuously formed along the longitudinal direction between the two conveying belts 23a, 23b. However, even if the belt body 23 is a single belt-shaped belt, openings such as circular shape, elliptical shape, slit shape, etc. may be intermittently formed along the longitudinal direction of this belt-shaped belt.

[0023] FIG. 4 is a plan view showing an enlarged view of the vicinity of the conveyance path 2a in FIG. 1. As shown in FIG. 4, the first imaging unit 30 includes a camera 31, a reflection illumination unit 32, and a transmission illumination unit 33. The camera 31 is composed of a CCD area camera, a CCD line camera, or the like, and is arranged so that the imaging direction is orthogonal to the conveyance path 2a in a plan view, and images the capsule C conveyed on the conveyance path 2a horizontally along the upper surface of the belt body 23. The imaging direction of the camera 31 is preferably substantially parallel to the upper surface of the belt body 23. However, when the lowermost part of the capsule C enters the opening 23c of the belt body 23, imaging may be performed obliquely downward from above the belt body 23. As an example, the angle formed by the imaging direction of the camera 31 and the upper surface of the belt body 23 can be set in the range of 0 to 15 degrees.

[0024] The reflection illumination unit 32 is arranged on the same side as the camera 31 with respect to the conveyance path 2a, and illuminates the capsule C from the same side as the camera 31 with a white LED or the like. The reflection illumination unit 32 of the present embodiment includes a ring illumination 32a capable of illuminating the capsule C uniformly from all around, a first polarizing plate 32b, and a second polarizing plate 32c. The illumination light of the ring illumination 32a may be infrared light or the like in addition to visible light.

[0025] The first polarizing plate 32b is formed in a ring shape and is arranged in the vicinity of the ring illumination 32a. By being interposed between the ring illumination 32a and the conveyance path 2a, the light emitted from the ring illumination 32a becomes linearly polarized and irradiates the capsule C. The second polarizing plate 32c is arranged in the vicinity of the camera 31 so as to cover the lens unit of the camera 31. By being interposed between the camera 31 and the conveyance path 2a, the surface reflected light of the capsule C passes through and is observed by the camera 31. The second polarizing plate 32c is arranged so that the polarization axis is orthogonal to the polarization axis of the first polarizing plate 32b. The second polarizing plate 32c is configured to be movable by a polarizing plate driving unit 32d such as an actuator. By rotating the drive shaft of the polarizing plate driving unit 32d, the second polarizing plate 32c can be retracted from in front of the camera 31 as shown by the two-dot chain line in FIG. 4. The polarizing plate driving unit 32d may be configured to linearly move the second polarizing plate 32c and retract it from in front of the camera 31.

[0026] The transmission illumination unit 33 is disposed on the side opposite to the camera 31 with respect to the conveyance path 2a, and illuminates the capsule C from the side opposite to the camera 31 with a white LED or the like. The transmission illumination unit 33 of the present embodiment is a surface light source in which a plurality of light emitting elements are arranged in a matrix. The illumination light of the transmission illumination unit 33 may be infrared light or the like in addition to visible light.

[0027] The marking unit 40 is a laser marking device, and can perform marking by heating and deforming the surface of the capsule C conveyed to a predetermined position by scanning with a laser spot. The surface of the capsule C may contain a discoloration-inducing oxide such as titanium oxide, yellow iron sesquioxide, or iron sesquioxide.

[0028] Examples of the laser light of the marking unit 40 include solid laser light such as YVO4 laser light, YLF laser light, and YAG laser light, gas laser light such as excimer laser light and CO2 (carbon dioxide) laser light, and liquid laser light such as dye laser light. In particular, CO2 laser light is easily absorbed on the surface of the capsule C and has low penetrability into the capsule C, so it can act effectively on the surface of the capsule C. Even when the capsule C is a transparent capsule, the surface can be whitely denatured to perform clear marking.

[0029] The marking unit 40 preferably can perform marking in accordance with the posture of the capsule C without moving or rotating the capsule C by converting the coordinate data in the reference coordinate system into the coordinate data in the processing coordinate system. Examples of such a device include an inkjet printing device in addition to the laser marking device.

[0030] Similar to the first imaging unit 30, the second imaging unit 50 includes a camera 51, a reflection illumination unit 52, and a transmission illumination unit 53. The reflection illumination unit 52 includes a ring illumination 52a, a first polarizing plate 52b, a second polarizing plate 52c, and a polarizing plate driving unit 52d. Since the configuration and arrangement of each element of the second imaging unit 50 are the same as those of each element of the first imaging unit 30, detailed description thereof is omitted.

[0031] The separating unit 60 is disposed between the first imaging unit 30 and the marking unit 40 in the vicinity of the transport path 2a, and can selectively separate the capsule C from the transport path 2a by injecting compressed air against the capsule C being transported on the transport path 2a. The specific configuration of the separating unit 60 is not particularly limited, and may be, for example, a pusher or the like that physically presses the capsule C on the transport path 2a to separate it from the transport path 2a. The capsule C separated from the transport path 2a by the operation of the separating unit 60 falls directly or via a shooter (not shown) onto the first transport device 10 disposed below the transport path 2a, and is transported again toward the transport path 2a.

[0032] As shown in the block diagram in FIG. 5, the operations of the above-described transport unit 2, first imaging unit 30, marking unit 40, second imaging unit 50, and separating unit 60 are controlled by the control unit 70.

[0033] Next, the operation of the capsule marking device 1 having the above-described configuration will be described. With the disk 11, intermediate ring 12, and rotating ring 13 of the first transport device 10 of the transport unit 2 being driven to rotate in the same direction, a plurality of capsules C are supplied onto the disk 11, so that the capsules C receive centrifugal force and move to the transport surface 13c of the rotating ring 13 via the transport surface 12c of the intermediate ring 12. In this way, the capsules C can be aligned in a row on the transport surface 13c and transported in the rotation direction of the rotating ring 13 (the direction of arrow D1 in FIG. 3). The rotation speeds of the disk 11, intermediate ring 12, and rotating ring 13 are preferably set such that the rotation speed of the disk 11 is the slowest and the rotation speed of the rotating ring 13 is the fastest, thereby promoting reliable aligned transport of the capsules C by the rotating ring 13.

[0034] The first transfer device 10 only needs to be configured to align the capsules C on the transfer surface 13c of the rotating ring 13 and transfer them in the rotating direction of the rotating ring 13. For example, without providing the intermediate ring 12, the rotation axes of the disk 11 and the rotating ring 13 may be inclined with respect to each other, and the capsules C supplied onto the disk 11 may be directly moved to the transfer surface 13c of the rotating ring 13. The rotation axis 13a of the rotating ring 13 is preferably arranged along the vertical direction as in the present embodiment, but may be arranged to extend in the vertical direction. For example, the rotation axis 13a may be slightly inclined with respect to the vertical direction.

[0035] The capsules C aligned and transferred by the first transfer device 10 toward the second transfer device 20 are sequentially adsorbed onto the belt body 23 near the lower part of the first pulley 21 by the suction of the suction part 25 and lifted, and are linearly transferred above the first pulley 21 and the second pulley 22 in the direction of arrow D2 in FIG. 3 while remaining in the adsorbed state. In this way, the capsules C aligned by the first transfer device 10 are transferred along the linear transfer path 2a while maintaining the aligned state by the second transfer device 20.

[0036] At the position where the capsules C are transferred from the rotating ring 13 to the belt body 23, as in the present embodiment, it is preferable that the transfer direction by the rotating ring 13 and the transfer direction by the belt body 23 coincide with each other, whereby the transfer of the capsules C can be surely performed. Further, by making the transfer speed of the capsules C by the belt body 23 faster than the transfer speed of the capsules C by the rotating ring 13, the alignment pitch of the capsules C aligned and transferred by the belt body 23 can be widened.

[0037] When the capsules C being transferred along the transfer path 2a pass through the first imaging unit 30, the sides thereof are imaged and the first imaging data is acquired. The control unit 70 sets a marking area on the capsules C based on the first imaging data. In this way, the first imaging step for the capsules C is performed.

[0038] When the capsule C is a colorless transparent capsule, as shown in Fig. 6(a), the control unit 70 turns on the transmission illumination unit 33 while turning off the reflection illumination unit 32, and illuminates the capsule C with the transmission illumination unit 33. Since part of the illumination light of the transmission illumination unit 33 passes through the capsule C and enters the camera 31, in the first imaging data, the outline of the capsule C appears, and when there is a seam (joint) in the imaging range of the capsule C, the part corresponding to the seam appears as a shadow. When illuminating with the transmission illumination unit 33, in order to suppress the decrease in the light amount of the illumination light, it is preferable to operate the polarizing plate driving unit 32d to retract the second polarizing plate 32c from in front of the camera 31.

[0039] On the other hand, when the capsule C is a colored transparent capsule or an opaque capsule, as shown in Fig. 6(b), the control unit 70 turns on the reflection illumination unit 32 while turning off the transmission illumination unit 33, and illuminates the capsule C with the reflection illumination unit 32. The illumination light of the reflection illumination unit 32 becomes linearly polarized by the first polarizing plate 32b and irradiates the capsule C, and the surface reflected light of the capsule C enters the camera 31 through the second polarizing plate 32c. Since the polarization axis of the second polarizing plate 32c is orthogonal to the polarization axis of the first polarizing plate 32b, the reflection of the illumination by the specular reflection light on the surface of the capsule C is removed, and only the diffuse reflection light is observed by the camera 31. Therefore, when the capsule C is a particularly colored transparent capsule, the glare on the surface of the capsule C can be effectively suppressed, and the first imaging data with clear outlines and seams of the capsule C can be obtained.

[0040] Which of the reflection illumination by the reflection illumination unit 32 and the transmission illumination by the transmission illumination unit 33 is selected may be determined in advance for each type of capsule C by comparing the first imaging data obtained under respective conditions. Alternatively, the light transmittance of the illumination light of the capsule C may be measured during conveyance by the conveyance unit 2, and the control unit 70 may be configured to automatically select based on this measurement result.

[0041] The setting of the marking area on the capsule C in the first imaging data is performed based on the posture of the capsule C conveyed on the conveyance path 2a. As shown in FIG. 7(a), the capsule C on the belt body 23 is usually adsorbed to the belt body 23 in the most stable posture. However, depending on the adsorption position of the capsule C, as shown in FIG. 7(b), the capsule C may be adsorbed to the belt body 23 in a slightly upright posture. The control unit 70 stores in advance the contours and marking areas corresponding to various postures of the capsule C, and by collating the contours included in the first imaging data, as shown in FIGS. 7(a) and 7(b), the marking area M corresponding to the posture of the capsule C can be set. The marking area M of the capsule C can also be specified by comparing the contour of the capsule C included in the first imaging data with a reference contour and calculating the rotation angle with respect to the reference contour.

[0042] The control unit 70 determines whether or not there is a seam in the marking area M set in the first imaging data, and if there is a seam, calculates the size of the seam. Since the position of the seam on the surface of the capsule C conveyed on the conveyance path 2a is random, as shown in FIG. 8(a), when the seam S does not overlap the marking area M, there is no problem of poor marking. On the other hand, as shown in FIG. 8(b), when the seam S overlaps the marking area M, the visibility of the marking may be reduced.

[0043] When the size of the seam within the marking area M is equal to or greater than a predetermined standard that has an adverse effect on the visibility of the marking, the control unit 70 activates the detachment unit 60 at the timing when the capsule C passes through the detachment unit 60, and detaches the capsule C from the transport path 2a. In this way, the detachment step of the capsule C is performed. The capsule C that has detached from the transport path 2a drops onto the first transport device 10 and is transported toward the transport path 2a, and the first imaging step is performed again. The capsule C that has detached from the transport path 2a may be configured to be collected in a container or the like, or may be supplied to the first transport device 10 after a certain amount of the capsule C has been stored. The size of the seam S within the marking area M can be, for example, the area ratio of the seam in the marking area M, but the length, thickness, etc. of the seam existing in the marking area M may also be used as the size of the seam.

[0044] When the size of the seam within the marking area M is less than the predetermined standard, the control unit 70 allows the capsule C to pass through without activating the detachment unit 60, and performs marking at the timing when the capsule C is transported to the marking unit 40. In the marking unit 40, the coordinate data in the reference coordinate system of the marking pattern composed of characters, numbers, symbols, figures, etc. or combinations thereof is stored in the memory in advance. The control unit 70 converts the coordinate data in the reference coordinate system into the coordinate data in the processing coordinate system so that the marking pattern is formed along the marking area set according to the posture of the capsule C, and performs drive control of the laser spot of the marking unit 40 in this processing coordinate system. In this way, the marking step for the capsule C is performed. When it is possible to form the marking pattern while avoiding the seam existing within the marking area M by rotation, shift, etc. of the coordinate data in the processing coordinate system, by performing such marking (that is, marking at a location other than the seam within the marking area), the adverse effect on the visibility of the marking pattern due to the seam can be further suppressed.

[0045] The marked capsule C is conveyed along the conveyance path 2a toward the second imaging unit 50. When passing through the second imaging unit 50, the side surface including the marking area is imaged, and the second imaging data is acquired. Based on the second imaging data, the control unit 70 determines the quality of the marking pattern within the marking area. In this way, the second imaging step for the capsule C is performed. The illumination condition of the second imaging unit 50 is preferably set to be the same as that of the first imaging unit 30. When the first imaging unit 30 performs reflected illumination by the reflection illumination unit 32, the second imaging unit 50 performs reflected illumination by the reflection illumination unit 52. On the other hand, when the first imaging unit 30 performs transmitted illumination by the transmission illumination unit 33, the second imaging unit 50 performs reflected illumination by the transmission illumination unit 53.

[0046] The control unit 70 determines the quality of the marking pattern by extracting the marking pattern data from the marking area of the second imaging data and comparing it with the reference pattern data corresponding to the marking pattern, which is pre-stored in the memory unit.

[0047] When there is no seam in the marking area, the quality of the marking pattern can be determined based on the second imaging data as described above. However, since there may be a seam with a size less than a predetermined standard in the marking area of the second imaging data, the determination of the quality of the marking pattern may also be performed based on the difference data between the first image data acquired by the first imaging unit 30 and the second image data acquired by the second imaging unit 50.

[0048] For example, as shown in FIG. 9(a), when there is a seam S with a size less than a predetermined standard in the marking area M of the first image data, the control unit 70 removes the marking area M of the first image data shown in FIG. 9(a) from the marking area M of the second image data shown in FIG. 9(b), thereby obtaining the differential data of the marking area M shown in FIG. 9(c). In the differential data shown in FIG. 9(c), a portion corresponding to the seam S shown in FIG. 9(a) is missing from the marking pattern P. However, since the size of the seam S is less than the predetermined standard that does not adversely affect the visibility of the marking pattern P, the quality of the marking pattern P can be accurately determined.

[0049] As shown in FIG. 1, the capsules C for which the quality of the marking pattern has been determined are sorted into a good product box 81 and a defective product box 82 by the control unit 70 controlling the operation of the sorting damper 80.

[0050] According to the capsule marking device 1 of the present embodiment, when the seam S of the capsule C overlaps the marking area M, it is determined whether the seam S is larger than a predetermined standard. If it is larger than the predetermined standard, the capsule C can be separated from the transport path 2a without forming a marking pattern, so that marking with good visibility can be efficiently performed.

Explanation of Signs

[0051] 1 Capsule marking device 2 Transport unit 2a Transport path 30 First imaging unit 40 Marking unit 50 Second imaging unit 60 Separation unit 70 Control unit C Capsule S Seam M Marking area

Claims

1. A capsule marking device comprising: a conveying unit that conveys a capsule along a conveying path; a first imaging unit that images the conveyed capsule to obtain first imaging data; a marking unit that marks the conveyed capsule; and a control unit that sets a marking area on the capsule based on the first imaging data and forms a marking pattern in the marking area by controlling the operation of the marking unit. The capsule marking device further comprises: a detachment unit that selectively detaches a capsule being conveyed from the conveying path, wherein the control unit detaches, without forming a marking pattern, a capsule in which the size of a seam within the marking area in the first imaging data is equal to or greater than a predetermined standard by controlling the operation of the detachment unit.

2. The capsule marking device according to claim 1, further comprising a second imaging unit that images the capsule on which the marking pattern is formed to obtain second imaging data, wherein the control unit determines the quality of the marking pattern based on difference data between the first image data and the second image data when the size of a seam within the marking area in the first imaging data is less than a predetermined standard.

3. The conveying path is linearly formed, The capsule marking device according to claim 1 or 2, wherein the first imaging unit comprises a camera arranged such that an imaging direction is orthogonal to the conveying path, a reflection illumination unit arranged on the same side of the conveying path as the camera, and a transmission illumination unit arranged on the opposite side of the conveying path from the camera.

4. The capsule marking device according to claim 3, wherein the reflection illumination unit comprises a ring illumination, a first polarizing plate arranged between the ring illumination and the conveying path, and a second polarizing plate arranged between the camera and the conveying path and having a polarization axis orthogonal to the polarization axis of the first polarizing plate.

5. The capsule marking device according to claim 4, wherein the reflection illumination unit further includes a polarizing plate driving unit that moves the second polarizing plate.

6. The capsule marking device according to any one of claims 1 to 5, wherein the control unit sets the marking area based on the posture of the capsule specified by the contour of the capsule in the first imaging data.

7. The marking unit irradiates a CO ２ laser to perform marking. The capsule marking device according to any one of claims 1 to 6.

8. A first imaging step of imaging a capsule conveyed on a conveyance path by a first imaging unit to obtain first imaging data, and setting a marking area on the capsule based on the first imaging data; A detachment step of detaching a capsule having a seam size in the marking area equal to or greater than a predetermined standard from the conveyance path; A capsule marking method comprising a marking step of forming a marking pattern in the marking area of the capsule conveyed through the detachment step.

9. The capsule marking method according to claim 8, wherein in the case where the size of the seam in the marking area in the first imaging data is less than a predetermined standard, the marking pattern is formed while avoiding the seam.

Images