JP2018186962A - Image acquisition device, inspection device, tablet printing device, and image acquisition method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology to clearly image tablets that can transmit a light while conveying them by a conveyor belt with absorption holes.SOLUTION: An image acquisition device includes a conveying mechanism, an epi-illumination part 71, a transparent illumination part 72, and an imaging part 73. The conveying mechanism moves a conveyor belt 12 and conveys tables 9 while absorbing and holding the tablets 9 in absorption holes 14 provided to the conveyor belt 12. The epi-illumination part 71 applies light onto the tablets 9 from a surface 12 side of the conveyor belt 12 where the tablets 9 are held, and the transparent illumination part 72 applies light onto the tablets 9 from a reverse surface 12b side of the conveyor belt 12. When imaging is performed by the imaging part 73, the light is applied from both the epi-illumination part 71 and the transparent illumination part 72. Thereby, a part of the tablet 9 that overlaps with the absorption hole 14 and a part that does not overlap with the absorption hole when viewed from the imaging part 73 can be both illuminated brightly, and the tablet 9 that can transmit light can be imaged clearly.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an image acquisition device that acquires an image of a tablet that can transmit light, an inspection device that includes the image acquisition device, a tablet printing device that includes the inspection device, and an image of a tablet that transmits light The present invention relates to an image acquisition method.

  Characters and codes for identifying the product are printed on the surface of the tablet which is one form of the medicine. Such characters and codes may be printed by engraving, but the engraving has a problem of low visibility. In particular, in recent years, the types of tablets have been diversified due to the spread of generic drugs. For this reason, in order to make it easy to identify a tablet, a technique for performing clear printing on the surface of the tablet by an ink jet method has attracted attention.

  In an inkjet tablet printing apparatus, ink droplets (hereinafter simply referred to as “ink droplets”) are ejected from a plurality of nozzles toward a tablet while the tablet is being conveyed. A conventional tablet printing apparatus is described in Patent Document 1, for example.

Japanese Patent Laying-Open No. 2015-223323

  In the tablet printing apparatus of Patent Document 1, the tablets are adsorbed and held in a plurality of adsorption holes provided in the conveyance belt. In addition, a plurality of imaging units are provided in the tablet printing apparatus of Patent Document 1. Each imaging unit captures a tablet to be conveyed and acquires an image of the tablet. The obtained image is used for, for example, inspecting the front and back of the tablet, the posture of the tablet, the presence or absence of damage to the tablet, and the quality of the printed image formed on the surface of the tablet.

  However, when the tablet is a transparent capsule, the back conveyor belt and suction hole can also be visually recognized through the tablet. For this reason, as shown in FIG. 9, when viewed from the imaging unit, a part or all of the tablet becomes a dark shadow, and a printed image formed on the surface of the tablet may not be captured clearly. In particular, the printed image formed on the surface of the tablet has a problem that a portion overlapping with the suction hole becomes a dark shadow and cannot be photographed clearly.

  This invention is made in view of such a situation, and it aims at providing the technique which can image | photograph a tablet clearly, conveying the tablet which can permeate | transmit light with the conveyance belt which has an adsorption hole. .

  In order to solve the above-mentioned problems, a first invention of the present application is an image acquisition device that acquires an image of a tablet capable of transmitting light, wherein the conveyance is performed while adsorbing and holding the tablet in an adsorption hole provided in a conveyance belt. By moving the belt, a transport mechanism that transports the tablets, an epi-illumination unit that emits light toward the tablets from the front surface side where the tablets of the transport belt are held, and from the back side of the transport belt toward the tablets The imaging unit while irradiating light from both the epi-illumination unit and the transmission illumination unit. An image of a tablet is obtained by taking a picture with a part.

  A second invention of the present application is the image acquisition device according to the first invention, wherein the imaging unit is disposed perpendicularly to the surface of the transport belt, and the epi-illumination unit is configured to be the sensor of the transport belt. A plurality of illumination units that irradiate light obliquely with respect to the surface.

  A third invention of the present application is the image acquisition device of the second invention, wherein the conveyor belt is opaque and has a surface that can reflect light while diffusing.

  4th invention of this application is an image acquisition apparatus of 3rd invention, Comprising: The reflection density of the said surface of the said conveyance belt is 0.3 or less.

  A fifth invention of the present application is the image acquisition device according to the third or fourth invention, wherein the diffuse reflectance of the surface of the conveyor belt is 50% or more.

  A sixth invention of the present application is the image acquisition device according to any one of the third to fifth inventions, wherein the surface of the conveyor belt can reflect visible light.

  7th invention of this application is an image acquisition apparatus of 6th invention, Comprising: The color of the said surface of the said conveyance belt is white.

  An eighth invention of the present application is the image acquisition device according to any one of the first to seventh inventions, wherein the incident light illumination unit and the transmission illumination unit can individually adjust the light amount.

  A ninth invention of the present application is an inspection device for inspecting a tablet, based on the image acquisition device according to any one of claims 1 to 8 and an image of the tablet acquired by the imaging unit. And a processing unit for inspecting the state of the tablet.

  A tenth aspect of the present invention is a tablet printing apparatus that performs printing on the surface of a tablet, the head ejecting ink droplets onto the surface of the tablet conveyed by the conveyance mechanism, and the inspection apparatus according to claim 9; Is provided.

  In an eleventh aspect of the present invention, an image of the tablet is acquired while the tablet is transported by moving the transport belt while adsorbing and holding the light transmissive tablet in the suction hole provided in the transport belt. The image acquisition method includes: a) an epi-illumination unit disposed on the front surface side where the tablets of the transport belt are held and a transmission illumination unit disposed on the back surface side of the transport belts. A step of irradiating light toward the surface, and b) a step of acquiring a tablet image by an imaging unit disposed on the front surface side of the conveyor belt while continuing the light irradiation of the step a). .

  The twelfth invention of the present application is the image acquisition method of the eleventh invention, wherein x) the step of adjusting the light amount of the epi-illumination unit, and y) the light amount of the transmission illumination unit is adjusted after the step x). And a step of

  According to the first to twelfth inventions of the present application, light is emitted from both the epi-illumination unit and the transmission illumination unit. Thereby, both the part which overlaps with an adsorption hole seeing from an image pick-up part, and the part which does not overlap can be illuminated brightly. Therefore, a tablet capable of transmitting light can be clearly photographed.

  In particular, according to the second invention of the present application, a tablet can be photographed in a direction perpendicular to the surface of the transport belt. Moreover, since the epi-illumination unit has a plurality of illumination units, the shadow of the tablet is hardly generated.

  In particular, according to the third invention of the present application, the light emitted from the epi-illumination part is reflected while being diffused on the surface of the conveyor belt, and illuminates the tablet from the back side. Thereby, when it sees from an imaging part, the part which does not overlap with an adsorption | suction hole among tablets becomes clearer.

  In particular, according to the eighth invention of the present application, the light amount of the epi-illumination unit and the light amount of the transmission illumination unit can be adjusted to an optimum light amount ratio. Thereby, the brightness of the tablet in a picked-up image can be equalized.

  In particular, according to the ninth invention of the present application, a tablet capable of transmitting light can be inspected based on a clear image.

  In particular, according to the twelfth aspect of the present invention, the light quantity adjustment of the epi-illumination unit and the transmission illumination unit can be easily performed.

It is the figure which showed the structure of the tablet printing apparatus. It is a fragmentary perspective view of a tablet conveyance mechanism. It is a bottom view of a head. It is the block diagram which showed the connection of a control part and each part in a tablet printing apparatus. It is the figure which showed the structure of the image acquisition part. It is the flowchart which showed the test | inspection procedure of a tablet. It is an image figure of a picked-up image. It is the flowchart which showed the procedure of light quantity adjustment. It is an image figure of the conventional picked-up image.

  Embodiments of the present invention will be described below with reference to the drawings. In the following description, a direction in which a plurality of tablets are transported is referred to as a “transport direction”, and a direction perpendicular to the transport direction is referred to as a “width direction”.

<1. Overall Configuration of Tablet Printing Device>
FIG. 1 is a diagram showing a configuration of a tablet printing apparatus 1 according to an embodiment of the present invention. The tablet printing apparatus 1 is an apparatus that prints an image such as a product name, a product code, a company name, and a logo mark on the surface of each tablet 9 while conveying a plurality of tablets 9 that are medicines. In the present embodiment, a transparent conical capsule tablet made of a material capable of transmitting light is used as the tablet. As shown in FIG. 1, the tablet printing apparatus 1 of this embodiment includes a tablet transport mechanism 10, a printing unit 20, a first image acquisition unit 30, a second image acquisition unit 40, and a control unit 50.

  The tablet transport mechanism 10 is a mechanism that transports a plurality of tablets 9 while holding them. The tablet transport mechanism 10 includes a pair of pulleys 11 and an annular transport belt 12 that is stretched between the pair of pulleys 11. The plurality of tablets 9 put into the tablet printing apparatus 1 are aligned at equal intervals and supplied to the surface of the conveyor belt 12 by a carry-in mechanism 60 including a vibration feeder, a conveyance drum, and the like. One of the pair of pulleys 11 is rotated by power obtained from the conveyance motor 13. Thereby, the conveyance belt 12 rotates in the direction of the arrow in FIG. At this time, the other of the pair of pulleys 11 is driven to rotate as the conveyor belt 12 rotates.

  FIG. 2 is a partial perspective view of the tablet transport mechanism 10. As shown in FIG. 2, the conveyance belt 12 is provided with a plurality of suction holes 14. The plurality of suction holes 14 are arranged at equal intervals in the transport direction and the width direction. As shown in FIG. 1, the tablet transport mechanism 10 includes a suction mechanism 15 that sucks out gas from the space inside the transport belt 12. When the suction mechanism 15 is operated, the space inside the conveyor belt 12 becomes a negative pressure lower than the atmospheric pressure. The plurality of tablets 9 are sucked and held in the suction holes 14 by the negative pressure.

  As described above, the plurality of tablets 9 are held on the surface of the transport belt 12 in a state of being aligned in the transport direction and the width direction. And the tablet conveyance mechanism 10 conveys the some tablet 9 in a conveyance direction by rotating the conveyance belt 12. FIG. Below the four heads 21 described later, the plurality of tablets 9 are conveyed in the horizontal direction.

  As shown in FIG. 1, the tablet transport mechanism 10 has a defective product discharge unit 16 and a non-defective product discharge unit 17. The defective product discharge unit 16 and the non-defective product discharge unit 17 are located downstream of the first image acquisition unit 30, the printing unit 20, and the second image acquisition unit 40 in the conveyance path.

  The defective product discharge unit 16 includes a defective product blow mechanism 161 disposed inside the conveyance belt 12 and a defective product collection unit 162 disposed below the defective product blow mechanism 161 across the conveyance belt 12. The defective product blow mechanism 161 blows gas only to the suction holes 14 that hold the tablets 9 determined to be defective among the plurality of suction holes 14 of the transport belt 12. If it does so, the said adsorption hole 14 will become a positive pressure higher than atmospheric pressure. As a result, the suction of the tablet 9 in the suction hole 14 is released, and the tablet 9 determined to be defective falls from the transport belt 12 to the defective product recovery unit 162.

  The non-defective product discharge unit 17 is disposed downstream of the defective product discharge unit 16 in the conveyance path. The non-defective product discharge unit 17 includes a non-defective product blow mechanism 171 disposed inside the conveyance belt 12 and a non-defective product collection unit 172 disposed below the good product blow mechanism 171 with the conveyance belt 12 interposed therebetween. The good product blow mechanism 171 blows gas toward the plurality of suction holes 14 of the transport belt 12. If it does so, the said adsorption hole 14 will become a positive pressure higher than atmospheric pressure. As a result, the adsorption of the tablet 9 in the suction hole 14 is released, and the tablet 9 determined to be non-defective falls from the transport belt 12 to the non-defective product collecting unit 172.

  The printing unit 20 is a part that records an image on the surface of the tablet 9 conveyed by the conveyance belt 12 by an inkjet method. As shown in FIG. 1, the printing unit 20 of the present embodiment has four heads 21. The four heads 21 are located above the transport belt 12 and are arranged in a line along the transport direction of the tablets 9. The four heads 21 eject ink droplets of different colors (for example, cyan, magenta, yellow, and black) toward the surface of the tablet 9. Then, a multicolor image is recorded on the surface of the tablet 9 by superimposing single color images formed by these colors. In addition, the edible ink manufactured by the raw material approved by the food hygiene law is used for the ink discharged from each head 21.

  FIG. 3 is a bottom view of one head 21. In FIG. 3, the conveyance belt 12 and the plurality of tablets 9 held on the conveyance belt 12 are indicated by a two-dot chain line. As shown enlarged in FIG. 3, a plurality of nozzles 211 capable of ejecting ink droplets are provided on the ejection surface 210 which is the lower surface of the head 21. In the present embodiment, a plurality of nozzles 211 are two-dimensionally arranged on the lower surface of the head 21 in the transport direction and the width direction. The nozzles 211 are arranged at different positions in the width direction. Thus, if the plurality of nozzles 211 are two-dimensionally arranged, the positions in the width direction of the nozzles 211 can be brought closer to each other. However, the plurality of nozzles 211 may be arranged in a line along the width direction.

  As a method for ejecting ink droplets from the nozzle 211, for example, a so-called piezo method is used in which a voltage is applied to a piezo element that is a piezoelectric element to deform the piezo element so that the ink in the nozzle 211 is pressurized and ejected. However, the ink droplet ejection method may be a so-called thermal method in which the ink in the nozzle 211 is ejected by heating and expanding by energizing the heater.

  The 1st image acquisition part 30 is a site | part which acquires the image of the tablet 9 before printing. The first image acquisition unit 30 is located on the downstream side of the conveyance path from the carry-in mechanism 60 and the upstream side of the conveyance path from the printing unit 20. The first image acquisition unit 30 images the plurality of tablets 9 that are transported by the transport belt 12. An image acquired by photographing is transmitted from the first image acquisition unit 30 to the control unit 50 described later. Based on the image obtained from the first image acquisition unit 30, the control unit 50 has no defect such as the presence or absence of the tablet 9 in each suction hole 14, the position of the tablet 9, the posture of the tablet 9, and the tablet 9. Check whether or not.

  The 2nd image acquisition part 40 is a site | part which acquires the image of the tablet 9 after printing. The second image acquisition unit 40 is located downstream of the printing unit 20 in the conveyance path and upstream of the defective product discharge unit 16 in the conveyance path. The second image acquisition unit 40 images a plurality of tablets 9 that are transported by the transport belt 12. An image acquired by photographing is transmitted from the second image acquisition unit 40 to the control unit 50 described later. The control unit 50 inspects the quality of the printed image formed on the surface of the tablet 9 based on the image obtained from the second image acquisition unit 40.

  Detailed configurations of the first image acquisition unit 30 and the second image acquisition unit 40 will be described later.

  The control unit 50 is means for controlling the operation of each unit in the tablet printing apparatus 1. FIG. 4 is a block diagram illustrating the connection between the control unit 50 and each unit in the tablet printing apparatus 1. As conceptually shown in FIG. 4, the control unit 50 includes a computer having a processor 51 such as a CPU, a memory 52 such as a RAM, and a storage unit 53 such as a hard disk drive. A computer program 531 for executing print processing is installed in the storage unit 53.

  As shown in FIG. 4, the control unit 50 includes the above-described tablet transport mechanism 10 (including the transport motor 13, the suction mechanism 15, the defective product blow mechanism 161, and the non-defective product blow mechanism 171), and the printing unit 20 (4 Two heads 21), a first image acquisition unit 30 (including an epi-illumination unit 71, a transmission illumination unit 72, and an imaging unit 73 described later), a second image acquisition unit 40 (an epi-illumination unit 71, transmission transmission described below). Unit 72 and imaging unit 73) and carry-in mechanism 60 are communicably connected to each other. The control unit 50 temporarily reads the computer program P and data stored in the storage unit 53 into the memory 52, and the processor 51 performs arithmetic processing based on the computer program P, thereby controlling the operation of each unit described above. To do. Thereby, the printing process with respect to the some tablet 9 advances.

<2. About Image Acquisition Unit>
<2-1. Configuration of image acquisition unit>
Next, a more detailed configuration of the first image acquisition unit 30 and the second image acquisition unit 40 will be described. In the present embodiment, the first image acquisition unit 30 and the second image acquisition unit 40 have the same configuration. For this reason, in the following description, the image acquisition applicable to both the 1st image acquisition part 30 and the 2nd image acquisition part 40 without distinguishing the 1st image acquisition part 30 and the 2nd image acquisition part 40. The configuration of the unit 70 will be described.

  In the following description, of the both surfaces of the conveyor belt 12, the outer surface (the surface on which the tablets 9 are held) is referred to as “front surface 12a”, and the inner surface is referred to as “back surface 12b”.

  FIG. 5 is a diagram illustrating a configuration of the image acquisition unit 70. As illustrated in FIG. 5, the image acquisition unit 70 includes an epi-illumination unit 71, a transmission illumination unit 72, and an imaging unit 73. In the present embodiment, the tablet transport mechanism 10 and the image acquisition unit 70 constitute an image acquisition device that acquires the image of the tablet 9 while transporting the tablet 9.

  The epi-illumination unit 71 is located on the surface 12a side of the conveyor belt 12, and is arranged at a distance from the surface 12a of the conveyor belt 12. The epi-illumination unit 71 irradiates the surface 12a of the conveyor belt 12 with light (for example, white light) at a predetermined imaging position P on the conveyance path. The epi-illumination unit 71 includes a first illumination unit 71A located on the upstream side in the transport direction with respect to the imaging unit 73 described later, and a second illumination unit 71B located on the downstream side in the transport direction with respect to the imaging unit 73. The first illumination unit 71A and the second illumination unit 71B each include a light source 711 and a diffusion plate 712. For example, an LED is used as the light source 711. The light emitted from the light source 711 passes through the diffusion plate 712 and is obliquely applied to the surface 12a of the conveyor belt 12 at the imaging position P.

  In the present embodiment, the surface 12a of the conveyor belt 12 is irradiated with light from two directions by the first illumination unit 71A and the second illumination unit 71B. Thereby, it can suppress that the shadow of tablet 9 itself arises in the imaging position P. FIG. Further, by arranging the diffusion plate 712 between the light source 711 and the imaging position P, unevenness of incident light can be suppressed.

  The transmitted illumination unit 72 is located on the back surface 12 b side of the transport belt 12 and is disposed at a distance from the back surface 12 b of the transport belt 12. The transmission illumination unit 72 irradiates the back surface 12 b of the transport belt 12 with light at the imaging position P. The transmitted illumination unit 72 includes a light source 721 and a diffusion plate 722. For example, an LED is used as the light source 721. The light emitted from the light source 721 passes through the diffusion plate 722 and is irradiated perpendicularly to the back surface 12 b of the transport belt 12 at the imaging position P. Therefore, when the suction hole 14 is located at the imaging position P, part of the light emitted from the transmission illumination unit 72 passes through the suction hole 14 and is irradiated to the surface 12 a side of the transport belt 12.

  The imaging unit 73 is located on the front surface 12a side of the conveyor belt 12 and is disposed at a distance from the front surface 12a of the conveyor belt 12. In addition, the imaging unit 73 is disposed so as to face the surface 12 a of the conveyor belt 12 in a vertical direction. The imaging unit 73 takes an image of the tablet 9 held on the transport belt 12 at the imaging position P. As illustrated in FIG. 5, the imaging unit 73 includes a lens 731 and a camera 732. As the camera 732, for example, a CCD camera or a CMOS camera capable of recording incident light as a digital image is used. The camera 732 may be a line camera in which image pickup elements are arranged one-dimensionally in the width direction, or may be an area camera in which image pickup elements are two-dimensionally arranged in the transport direction and the width direction.

<2-2. Inspection procedure using image acquisition unit>
FIG. 6 is a flowchart showing a procedure for inspecting the tablet 9 using the image acquisition unit 70.

  When the tablet 9 is inspected, first, irradiation of light from both the epi-illumination unit 71 and the transmission illumination unit 72 is started (step S11). And imaging with the imaging part 73 is performed, continuing irradiation of the light from both the epi-illumination part 71 and the transmission illumination part 72 (step S12).

  A part of the light emitted from the epi-illumination unit 71 is reflected on the surface 12 a of the transport belt 12 as shown by an arrow A 1 in FIG. 5, passes through the tablet 9 and the lens 731, and enters the camera 732. Further, a part of the light emitted from the transmission illumination unit 72 passes through the suction hole 14 of the transport belt 12 and further passes through the tablet 9 and the lens 731 as indicated by an arrow A2 in FIG. Is incident on.

  For this reason, the part of the tablet 9 that does not overlap the suction hole 14 when viewed from the imaging unit 73 is illuminated brightly by the light from the epi-illumination unit 71. In addition, a portion of the tablet 9 that overlaps the suction hole 14 when viewed from the imaging unit 73 is brightly illuminated by the light from the transmission illumination unit 72. That is, the light from the epi-illumination unit 71 and the light from the transmission illumination unit 72 are inserted from the back side of the tablet 9 so that the entire tablet 9 is illuminated brightly. Therefore, as shown in FIG. 7, the imaging unit 73 can clearly photograph the entire transparent tablet 9. When a printed image is formed on the surface of the tablet 9, the printed image can also be captured clearly.

  The image photographed by the imaging unit 73 is transmitted to the control unit 50 as digital data. The controller 50 inspects the tablet 9 based on the obtained image (step S13). The control unit 50 inspects, for example, the position of the tablet 9, the posture of the tablet 9, and whether or not the tablet 9 has a defect such as a chip or the printed image formed on the surface of the tablet 9 has no defect. . As a result, each tablet 9 is sorted into a good product and a defective product.

  That is, in the present embodiment, the computer as the control unit 50 functions as a processing unit that inspects the state of the tablet 9 based on the captured image obtained from the imaging unit 73. In the present embodiment, the tablet transport mechanism 10, the image acquisition unit 70, and the control unit 50 constitute an inspection device that inspects the tablet 9.

<2-3. About the surface properties of the conveyor belt>
Next, the surface properties of the conveyor belt 12 will be described.

  As described above, the light emitted from the epi-illumination unit 71 is reflected on the surface 12 a of the conveyor belt 12, and a part of the light needs to go to the camera 732. For this reason, it is desirable that at least the surface 12a of the conveyor belt 12 is opaque and can be reflected while diffusing visible light. That is, it is desirable that the surface 12a of the conveyor belt 12 does not transmit light and is not a mirror surface or a glossy metal surface.

  Specifically, it is desirable that the surface 12a of the conveyor belt 12 has a lower reflection density than a metal surface such as stainless steel. For example, the reflection density of the surface 12a of the transport belt 12 is desirably 0.3 or less, and more desirably 0.2 or less. Alternatively, it is desirable that the surface 12a of the conveyor belt 12 has a higher diffuse reflectance than a metal surface such as stainless steel. For example, the diffuse reflectance of the surface 12a of the conveyor belt 12 is desirably 50% or more, and more desirably 60% or more.

  In addition, it is desirable that the color of the printed image formed on the surface of the tablet 9 and the color of the surface 12a of the transport belt 12 have substantially opposite colors (complementary colors). For example, when the color of the printed image formed on the surface of the tablet 9 is black or a dark color close to black, the color of the surface 12a of the transport belt 12 is desirably white or a light color close to white. For example, when the color of the printed image formed on the surface of the tablet 9 is blue-purple, the color of the surface 12a of the transport belt 12 may be yellow, which is the opposite color of blue-purple.

  Moreover, when the printed image formed on the surface of the tablet 9 is multicolored like this embodiment, the color of the surface 12a of the conveyance belt 12 is desirably white or a light color close to white. Specifically, the conveyance belt 12 may be formed of white or light color resin. For example, polyurethane can be used as the resin.

  As described above, by appropriately setting the surface property of the conveyance belt 12, it is possible to take a clearer image of a printed image formed in a portion of the tablet 9 that does not overlap the suction hole 14 when viewed from the imaging unit 73.

<2-4. About the light intensity adjustment of the epi-illumination unit and the transmission illumination unit>
Next, the light amount adjustment of the epi-illumination unit 71 and the transmission illumination unit 72 will be described.

  The epi-illumination unit 71 and the transmission illumination unit 72 can individually adjust the amount of light. Before the tablet printing apparatus 1 is operated, the light emitted from the epi-illumination unit 71 and the light emitted from the transmission illumination unit 72 are adjusted to optimum light amounts, respectively.

  FIG. 8 is a flowchart showing a procedure for adjusting the light amount of the epi-illumination unit 71 and the transmission illumination unit 72. As shown in FIG. 8, when adjusting the light amount, first, the exposure time of the camera 732 is determined (step S21). For example, the exposure time is determined according to the transport speed of the tablet 9 by the tablet transport mechanism 10. Specifically, exposure time is shortened, so that the conveyance speed of the tablet 9 is quick.

  Next, the light quantity of the epi-illumination unit 71 is adjusted (step S22). Here, first, the tablet 9 is arranged at the imaging position P, and light from the epi-illumination unit 71 is irradiated. Then, the amount of light received by the camera 732 is confirmed while changing the light emission intensity of the epi-illumination unit 71. Specifically, the brightness of the portion of the tablet 9 that does not overlap with the suction hole 14 as viewed from the camera 732 is confirmed. Then, the light emission intensity of the epi-illumination unit 71 is set so that the brightness of the part becomes a preset level. Thereby, among the light emitted from the epi-illumination unit 71, the amount of light reflected by the surface 12a of the conveyor belt 12 and incident on the camera 732 of the imaging unit 73 via the tablet 9 is appropriately adjusted. .

  Subsequently, the light amount of the transmitted illumination unit 72 is adjusted (step S23). Here, in addition to the light irradiation from the epi-illumination unit 71, the light irradiation from the transmission illumination unit 72 is also performed. Then, the amount of light received by the camera 732 is confirmed while changing the light emission intensity of the transmitted illumination unit 72. Specifically, when viewed from the camera 732, the light emitted from the transmissive illumination unit 72 is set so that the brightness of the portion of the tablet 9 that overlaps the suction hole 14 is the same level as the brightness of the portion that does not overlap the suction hole 14. Set the strength. Thereby, the brightness of the tablet 9 in the photographed image is made uniform.

  In the image acquisition unit 70, the amount of light emitted from the epi-illumination unit 71 and incident on the camera 732 is affected by the reflectance of the surface 12 a of the transport belt 12. Therefore, the epi-illumination unit 71 needs to make a strict adjustment in order to obtain a desired brightness. For this reason, it is preferable to adjust the light quantity of the epi-illumination part 71 first, and to adjust the light quantity of the transmissive illumination part 72 according to the epi-illumination part 71 after that as mentioned above. Thereby, the light quantity adjustment work of the epi-illumination unit 71 and the transmission illumination unit 72 is facilitated.

  In addition, the adjustment process of step S21-S23 may be performed manually by the user of the tablet printing apparatus 1, and the control unit 50 may be automatically executed according to a preset computer program.

<3. Modification>
As mentioned above, although main embodiment of this invention was described, this invention is not limited to said embodiment.

  In the above embodiment, the first illumination unit 71A and the second illumination unit 71B of the epi-illumination unit 71 are arranged on both sides in the transport direction with the imaging unit 73 interposed therebetween. However, the first illumination unit 71A and the second illumination unit 71B may be arranged on both sides in the width direction with the imaging unit 73 interposed therebetween. Moreover, the epi-illumination part 71 may have three or more illumination parts.

  In the above embodiment, the emission intensity of each of the epi-illumination unit 71 and the transmission illumination unit 72 is adjusted in steps S22 to S23. However, each light emission time may be adjusted with the light emission intensity of each of the epi-illumination unit 71 and the transmission illumination unit 72 being constant. That is, the adjustment of the “light quantity” in the present invention includes both the case where the light emission intensity is adjusted and the case where the light emission time is adjusted.

  In addition to the configuration of the above embodiment, the tablet printing apparatus 1 may have a drying mechanism that dries the ink attached to the tablet 9. The drying mechanism may be provided downstream of the printing unit 20 in the conveyance direction and upstream of the defective product discharge unit 16 in the conveyance direction. The drying mechanism may be, for example, a mechanism that blows hot air toward the tablets 9 that are transported by the transport belt 12.

  In the above embodiment, printing is performed only on the surface of the tablet 9 held on the conveyor belt 12 that faces the head 21. However, you may provide the same tablet printing apparatus which has the tablet conveyance mechanism 10 and the printing part 20 in the downstream of the conveyance direction of said tablet printing apparatus 1. FIG. And you may make it print on the surface where the tablet 9 differs with a previous tablet printing apparatus and a subsequent tablet printing apparatus.

  In the above embodiment, the printing unit 20 is provided with the four heads 21. However, the number of heads 21 included in the printing unit 20 may be 1 to 3, or 5 or more.

  In addition, the “tablet” to be processed in the present invention is not necessarily limited to a tablet as a pharmaceutical product. The image acquisition device of the present invention may acquire an image of a tablet or tablet confectionery as a health food.

  In addition, the detailed configurations of the image acquisition device, the inspection device, and the tablet printing device may be different from those of the present application. Moreover, you may combine suitably each element which appeared in said embodiment and modification in the range which does not produce inconsistency.

DESCRIPTION OF SYMBOLS 1 Tablet printer 9 Tablet 10 Tablet conveyance mechanism 11 Pulley 12 Conveyor belt 12a Front surface 12b Back surface 13 Conveyance motor 14 Suction hole 15 Suction mechanism 16 Defective product discharge part 17 Non-defective product discharge part 20 Printing part 21 Head 30 First image acquisition part 40 Second image acquisition unit 50 Control unit 60 Carry-in mechanism 70 Image acquisition unit 71 Epi-illumination unit 71A First illumination unit 71B Second illumination unit 72 Transmission illumination unit 73 Imaging unit 711 Light source 712 Diffuser plate 721 Light source 722 Diffuser plate 731 Lens 732 Camera P Imaging position

Claims (12)

An image acquisition device for acquiring an image of a tablet capable of transmitting light,
A transport mechanism for transporting the tablets by moving the transport belt while adsorbing and holding the tablets in the suction holes provided in the transport belt;
An epi-illumination unit that irradiates light from the surface side where the tablets of the conveyor belt are held toward the tablets;
A transmission illumination unit that emits light toward the tablet from the back side of the conveyor belt;
An imaging unit that photographs tablets from the front side of the conveyor belt;
With
An image acquisition apparatus that acquires an image of a tablet by performing imaging by the imaging unit while irradiating light from both the epi-illumination unit and the transmission illumination unit. The image acquisition device according to claim 1,
The imaging unit is disposed vertically opposite to the surface of the conveyor belt,
The said epi-illumination part is an image acquisition apparatus which has several illumination part which irradiates light diagonally with respect to the said surface of the said conveyance belt. The image acquisition device according to claim 2,
The image acquisition apparatus, wherein the conveyor belt is opaque and has a surface that can reflect light while diffusing light. The image acquisition device according to claim 3,
The image acquisition device wherein the reflection density of the surface of the conveyor belt is 0.3 or less. The image acquisition device according to claim 3 or 4, wherein:
The image acquisition device wherein the diffuse reflectance of the surface of the conveyor belt is 50% or more. The image acquisition device according to any one of claims 3 to 5,
The image acquisition device, wherein the surface of the conveyor belt can reflect visible light. The image acquisition device according to claim 6,
The image acquisition device wherein the color of the surface of the conveyor belt is white. The image acquisition device according to any one of claims 1 to 7,
The epi-illumination unit and the transmission illumination unit are image acquisition devices capable of individually adjusting the amount of light. An inspection device for inspecting tablets,
The image acquisition device according to any one of claims 1 to 8,
Based on the tablet image acquired by the imaging unit, a processing unit for inspecting the state of the tablet,
An inspection apparatus comprising: A tablet printing apparatus for printing on the surface of a tablet,
A head for ejecting ink droplets onto the surface of the tablet conveyed by the conveyance mechanism;
An inspection apparatus according to claim 9;
A tablet printing apparatus. An image acquisition method for acquiring an image of a tablet while transporting the tablet by moving the transport belt while adsorbing and holding a light transmissive tablet in an adsorption hole provided in the transport belt. ,
a) irradiating light toward the tablet from both the epi-illumination unit disposed on the front surface side where the tablet of the transport belt is held and the transmission illumination unit disposed on the back side of the transport belt; ,
b) acquiring an image of a tablet by an imaging unit arranged on the surface side of the transport belt while continuing the light irradiation of the step a);
An image acquisition method comprising: The image acquisition method according to claim 11,
x) adjusting the amount of light of the epi-illumination unit;
y) After the step x), the step of adjusting the light quantity of the transmitted illumination unit;
An image acquisition method comprising: