JP2019166199A - Printer and printing method - Google Patents

Abstract

To provide a technique capable of performing printing on a surface of a granular material in a direction of a secant line without changing a direction of holding the granular material.SOLUTION: A printer for printing an image on a surface 91 of a granular material includes a conveyance mechanism, an imaging unit 102, a rear surface secant line detection unit and a printing unit. The conveyance mechanism conveys the granular material while holding it from a rear surface 92 side. The imaging unit generates image data by imaging the surface and a side surface 93 of the conveyed granular material. The rear surface secant line detection unit detects whether or not there is a secant line on the rear surface, and detects a direction of the secant line on the basis of the image data. The printing unit performs printing on the surface of the granular material on the basis of the direction of the secant line detected by the rear surface secant line detection unit. With this, the printer can print the image correctly on the surface of the granular material in the detected direction of the secant line without changing a direction of holding the granular material after detecting the secant line on the rear surface of the granular material.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a printing apparatus and a printing method for printing an image on a granular material such as a tablet by an inkjet method.

  Conventionally, images of product names, product codes, company names, logos, etc. are recorded on at least one of the front and back surfaces of granular materials such as tablets as pharmaceuticals for the purpose of product identification. For recording these images, for example, an ink jet method is used. Thereby, it is possible to print clearly on the granular material. Further, the pressure applied to the granular material during printing can be reduced, and scratches and breakage can be suppressed. FIG. 9 is a perspective view of the tablet 9X on which printing has been performed. As shown in FIG. 9, a dividing line 90X for dividing the tablet in half may be formed on one of the front surface and the back surface of the tablet 9X. It is necessary to print on the tablet 9X having such a dividing line 90X at a rotation angle corresponding to the direction of the dividing line 90X. A printing machine that prints on the tablet 9X having the secant line 90X is described in Patent Document 1, for example.

International Publication No. 2014/013953

  The printing machine of Patent Document 1 includes a transport device that transports tablets, a first image-capturing printing unit that captures and prints a surface of the tablets that are directed downward, and an upper portion of the tablets that are transported. A second imaging printing unit that images and prints the side facing surface. The transport device is disposed on the downstream side of the first transport unit and the first transport unit that transports the tablet while being in contact with the upper side of the tablet, and transports the tablet while being in contact with the lower side of the tablet. A second transport unit. A 1st imaging printing unit images and prints the tablet currently conveyed by the 1st conveyance part. The second imaging / printing unit images and prints the tablets transported to the second transport unit. Further, in Patent Literature 1, each tablet to be transported is arranged so that the direction of the dividing line is a predetermined direction based on the imaging result of at least one of the first imaging printing unit and the second imaging printing unit. The structure of the parting direction alignment part to rotate is disclosed. Thereby, printing can be performed in a state where the direction of the dividing line of the tablet is aligned in a predetermined direction.

  In recent years, information (number of characters, etc.) printed on tablets tends to increase. Therefore, there is an increasing need for printing while moving the printing position to the vicinity of the center of the tablet and performing more accurate positioning with respect to the dividing line because of the printing space.

  In the printing machine of Patent Document 1, for example, after aligning the direction of the dividing line on the surface of the tablet in a predetermined direction based on the imaging result by the first imaging printing unit, the dividing line is held while inverting the front and back of the tablet. It becomes the structure which prints on the surface which does not. For this reason, when the front and back of the tablet are reversed, the direction (rotation angle) of the dividing line is shifted, and there is a possibility that the printing direction with respect to the direction of the dividing line is shifted.

  The present invention has been made in view of such circumstances, and after detecting the dividing line on the back surface of a granular material such as a tablet, the granularity is maintained along the direction of the detected dividing line without changing the direction of holding the granular material. An object is to provide a technique capable of printing on the surface of an object.

  In order to solve the above-mentioned problem, the first invention of the present application is a printing apparatus that prints an image on the surface of a granular material by an ink jet method, and conveys the granular material while holding it from the back side, and the conveying By imaging the front and side surfaces of the granular material conveyed by a mechanism, an imaging unit that generates image data of the granular material, and detecting whether there is a secant on the back surface based on the image data And when there is the secant on the back side, the direction of the secant is detected, and based on the direction of the secant detected by the back side secant detecting unit, the surface of the granular material is printed. A printing unit.

  2nd invention of this application is a printing apparatus of 1st invention, Comprising: The said back surface dividing line detection part is the said back surface based on the position of the edge part of the said dividing line which appears in the said side of the said granular material in the said image data. The direction of the secant line at is detected.

  3rd invention of this application is a printing apparatus of 1st invention or 2nd invention, Comprising: It further has several illumination which can irradiate light to the said granular material, These illuminations are the optical axes of the said imaging part A plurality of side illuminations that are disposed so as to surround at least a part of the granular material, and at least one on-axis illumination that is disposed on the optical axis of the imaging unit. The printing apparatus further includes an optical system that guides the light reflected by the granular material irradiated with light by the on-axis illumination to the imaging unit while bypassing the on-axis illumination, and the imaging unit includes: The surface and the side surface of the granular material irradiated with light by a plurality of irradiation patterns using the plurality of side illuminations and the on-axis illumination are imaged.

  4th invention of this application is a printing apparatus of 3rd invention, Comprising: The said optical system contains the some reflective mirror which each has a reflective surface which inclines and faces with respect to the said surface and the said side surface of the said granular material. The imaging unit images the side surface of the granular material from two or more different directions in the circumferential direction via the plurality of reflection mirrors.

  5th invention of this application is a printing apparatus of 4th invention, Comprising: The said imaging part images the said side of the said granular material from two directions which mutually shifted | deviated 90 degree | times to the circumferential direction.

  6th invention of this application is a printing apparatus of 4th invention, Comprising: The said imaging part images the said side surface of the said granular material from two directions mutually shifted | deviated 180 degree | times to the circumferential direction.

  7th invention of this application is a printing apparatus of 3rd invention, Comprising: The said optical system contains the reflective mirror which has a reflective surface which inclines and faces with respect to the said surface and the said side surface of the said granular material, The said reflection The elevation angle of the mirror with respect to the granular material is larger than 0 degree and not larger than 30 degrees.

  An eighth invention of the present application is the printing apparatus according to any one of the first invention to the seventh invention, wherein it is detected whether the surface has the secant based on the image data, and When there is the secant on the surface, the surface further includes a surface secant detecting unit, and the printing unit detects the direction of the granular material based on the direction of the secant detected by the surface secant detecting unit. Print on the surface.

  A ninth invention of the present application is the printing apparatus according to any one of the first to eighth inventions, wherein the transport mechanism has a first transport belt that transports the back side of the granular material while adsorbing the back surface. And the said imaging part images the said surface and the said side surface of the said granular material on the conveyance path | route by the said 1st conveyance belt.

  A tenth aspect of the present invention is the printing apparatus according to the ninth aspect, wherein the imaging unit is located on the opposite side of the first conveying belt with respect to the granular material.

  An eleventh invention of the present application is a printing method for printing an image on the surface of a granular material by an inkjet method, wherein a) a step of conveying the granular material while holding it from the back surface side, and b) a middle of the step a). Then, a step of generating image data of the granular material by imaging the front and side surfaces of the granular material, and c) a secant on the back surface based on the image data generated in the step b). Detecting the presence of the dividing line on the back surface, and detecting the direction of the dividing line on the back surface; and d) based on the direction of the dividing line detected in the step c). Printing on the surface.

  According to the first to eleventh inventions of the present application, the direction of the dividing line on the back surface is detected while holding the granular material from the back surface side, and further, printing is performed on the surface of the granular material based on the direction of the dividing line on the back surface. it can. Thereby, it is possible to suppress the occurrence of a shift in the direction of the dividing line, and to print with a more accurate position and direction with respect to the direction of the dividing line.

  In particular, according to the fourth aspect of the present invention, the direction of the secant on the back surface can be detected more accurately.

  In particular, according to the fifth invention of the present application, it is possible to detect any direction of the secant line on the back surface.

  In particular, according to the sixth invention of the present application, even when the granular material is held in an inclined state with respect to the horizontal plane and the dividing line is inclined with respect to the horizontal plane, the direction of the dividing line on the back surface can be detected.

1 is a diagram illustrating a configuration of a printing apparatus. FIG. 6 is a perspective view of the vicinity of a transport drum. It is a fragmentary perspective view of a 1st conveyance belt. It is a top view which illustrates arrangement | positioning of a 1st imaging unit. It is a bottom view of a head. FIG. 3 is a block diagram illustrating a connection between a control unit and each unit in the printing apparatus. It is sectional drawing which illustrates the detailed structure of a 1st imaging unit. It is the block diagram which showed a part of function of the control part notionally. It is a perspective view of a tablet.

  Embodiments of the present invention will be described below with reference to the drawings. In the following description, the direction in which a plurality of granular materials are conveyed is the “conveying direction”, the direction perpendicular to the conveying direction is the “width direction”, and the direction is perpendicular to the conveying direction and the width direction. Is referred to as a “height direction”.

<1. Configuration of printing device>
FIG. 1 is a diagram illustrating a configuration of a printing apparatus 1 according to an embodiment of the present invention. The printing apparatus 1 of the present embodiment prints an image such as a product name, a product code, a company name, and a logo mark on the surface 91 of each tablet 9 while conveying a plurality of tablets 9 that are granular materials by an inkjet method. Device. The tablet 9 of this embodiment has a disk shape (see FIGS. 3 and 9 described later). However, the shape of the tablet 9 may be another shape such as an elliptical shape. In the following description, among the both surfaces of the tablet 9, the surface is positioned on the opposite side of the first conveyance belt 412 to be described later that conveys the tablet 9, or the opposite side of the second conveyance belt 512 to be described later that conveys the tablet 9. The surface to be contacted is referred to as “front surface 91”, and the surface that contacts the first transport belt 412 or the surface that contacts the second transport belt 512 among both surfaces of the tablet 9 is referred to as “back surface 92”. However, the descriptions of “front surface 91” and “back surface 92” are used to identify both surfaces of the tablet 9, and are limited as any specific surface being “front surface 91” or “back surface 92”. It is not a thing.

  The tablet 9 has a groove-shaped dividing line 90 for dividing the tablet 9 in half (see FIGS. 3 and 9 described later). The secant 90 passes through the center of the surface of the tablet 9 where the secant 90 is formed (hereinafter referred to as “secant plane”), and extends straight to both ends of the secant plane. In the present embodiment, it is assumed that the dividing line 90 is formed only on one of the opposing surfaces of the disk-shaped tablet 9. However, the secant 90 may be formed on both surfaces of the tablet 9 that face each other.

  As illustrated in FIG. 1, the printing apparatus 1 according to the present embodiment includes a hopper 10, a feeder unit 20, a transport drum 30, a first printing unit 40, a second printing unit 50, a carry-out conveyor 60, and a control unit 70. The transport mechanism for transporting the tablets 9 is formed by the hopper 10, the feeder unit 20, the transport drum 30, the first transport conveyor 41 of the first printing unit 40, the second transport conveyor 51 of the second printing unit 50, and the unloading conveyor 60. Has been.

  The hopper 10 is an input unit for receiving a large number of tablets 9 in the apparatus. The hopper 10 is disposed at the top of the casing 100 of the printing apparatus 1. The hopper 10 has an opening 11 located on the upper surface of the housing 100 and a funnel-shaped inclined surface 12 that gradually converges as it goes downward. The plurality of tablets 9 put into the opening 11 flows into the rectilinear feeder 21 along the inclined surface 12.

  The feeder unit 20 is a mechanism that transports the plurality of tablets 9 put into the hopper 10 to the transport drum 30. The feeder unit 20 of the present embodiment includes a linear feeder 21, a rotary feeder 22, and a supply feeder 23. The rectilinear feeder 21 has a flat vibration trough 211. The plurality of tablets 9 supplied from the hopper 10 to the vibration trough 211 are conveyed to the rotary feeder 22 side by the vibration of the vibration trough 211. The rotary feeder 22 has a disk-shaped turntable 221. The plurality of tablets 9 that have dropped from the vibration trough 211 onto the upper surface of the turntable 221 are collected near the outer periphery of the turntable 221 by centrifugal force generated by the rotation of the turntable 221.

  The supply feeder 23 has a plurality of cylindrical portions 231 extending vertically downward from the outer peripheral portion of the turntable 221 to the transport drum 30. FIG. 2 is a perspective view of the vicinity of the transport drum 30. As shown in FIG. 2, a plurality (three in the example of FIG. 2) cylindrical portions 231 are arranged in parallel to each other. Each of the plurality of tablets 9 conveyed to the outer peripheral portion of the turntable 221 is supplied to any one of the plurality of cylindrical portions 231 and falls in the cylindrical portion 231. A plurality of tablets 9 are stacked in each cylindrical portion 231. As described above, the plurality of tablets 9 are aligned and supplied to the plurality of transport rows by being distributed and supplied to the plurality of cylindrical portions 231. Then, the plurality of tablets 9 in each conveyance row are supplied to the conveyance drum 30 in order from the lower end.

  The transport drum 30 is a mechanism that delivers a plurality of tablets 9 from the supply feeder 23 to the first transport conveyor 41. The conveyance drum 30 has a substantially cylindrical outer peripheral surface. The conveyance drum 30 is rotated in the direction of the arrow in FIGS. 1 and 2 around a rotation axis extending in the width direction by power obtained from a motor (not shown). As shown in FIG. 2, a plurality of holding portions 31 are provided on the outer peripheral surface of the transport drum 30. The holding unit 31 is a recess that is recessed inward from the outer peripheral surface of the transport drum 30. The plurality of holding portions 31 are arranged along the circumferential direction on the outer circumferential surface of the conveyance drum 30 at the position in the width direction corresponding to each of the plurality of conveyance rows described above. An adsorption hole 32 is provided at the bottom of each holding part 31. The suction hole 32 is formed in a circular shape corresponding to the shape of the tablet 9.

  A suction mechanism (not shown) is provided inside the transport drum 30. When the suction mechanism is operated, a negative pressure lower than the atmospheric pressure is generated in each of the plurality of suction holes 32. The holding unit 31 sucks and holds the tablets 9 supplied from the supply feeder 23 one by one with the negative pressure. In addition, a blow mechanism (not shown) is provided inside the transport drum 30. The blow mechanism blows locally pressurized gas from the inside of the transport drum 30 toward the first transport conveyor 41 described later. Thereby, in the holding part 31 which does not oppose the 1st conveyance conveyor 41, adsorption | suction of the tablet 9 is cancelled | released only in the holding part 31 which opposes the 1st conveyance conveyor 41, maintaining the adsorption | suction state of the tablet 9. FIG. Thus, the transport drum 30 rotates while adsorbing and holding the plurality of tablets 9 supplied from the supply feeder 23, and can deliver these tablets 9 to the first transport conveyor 41.

  The first printing unit 40 is a processing unit for printing an image on one surface of the tablet 9. As shown in FIG. 1, the first printing unit 40 includes a first transport conveyor 41, a first imaging unit 42, a first head unit 43, a first inspection camera 44, and a first fixing unit 45.

  The first conveyor 41 includes a pair of first pulleys 411 and an annular first conveyor belt 412 that is stretched between the pair of first pulleys 411. The first conveyor belt 412 is disposed so that a part thereof is opposed to the outer peripheral surface of the conveyor drum 30. One of the pair of first pulleys 411 rotates with power obtained from a motor (not shown). As a result, the first conveyor belt 412 rotates in the direction of the arrow in FIGS. At this time, the other of the pair of first pulleys 411 rotates following the rotation of the first conveying belt 412.

  As shown in FIG. 2, the first conveyor belt 412 is provided with a plurality of holding portions 413. FIG. 3 is a partial perspective view of the first transport belt 412. As shown in FIG. 3, each holding portion 413 is a portion that protrudes in a cylindrical shape further outward from the outer surface of the first transport belt 412 (the surface on the opposite side of the first pulley 411). Each holding portion 413 is formed in a cylindrical shape corresponding to the shape of the tablet 9. In addition, the plurality of holding units 413 are arranged in the transport direction at the position in the width direction corresponding to each of the plurality of transport rows. That is, the plurality of holding units 413 are arranged at intervals in the width direction and the transport direction. The intervals in the width direction of the plurality of holding portions 413 in the first conveyance belt 412 are equal to the intervals in the width direction of the plurality of holding portions 31 in the conveyance drum 30.

  An adsorption hole 415 is provided at the bottom of the cavity 414 inside each holding part 413. The first conveyor 41 has a suction mechanism (not shown) inside the first conveyor belt 412. When the suction mechanism is operated, a negative pressure lower than the atmospheric pressure is generated in each of the plurality of suction holes 415. Each holding part 413 adsorbs and holds the tablets 9 delivered from the transport drum 30 one by one with the negative pressure. Accordingly, the first transport belt 412 transports the plurality of tablets 9 while being held from the back surface 92 side in a state where the tablets 9 are aligned in a plurality of transport rows spaced in the width direction. The plurality of tablets 9 transported to the first transport belt 412 include a tablet 9 held by the holding unit 413 from the secant surface side having the secant line 90 and a surface not having the secant line 90 (hereinafter referred to as “main surface”). The tablet 9 held by the holding part 413 from the side is mixed.

  Further, the first transport belt 412 is provided with a blow mechanism (not shown). When the blow mechanism is operated, the suction hole 415 becomes a positive pressure higher than the atmospheric pressure in the holding portion 413 facing the second transport conveyor 51 described later. Thereby, the adsorption of the tablets 9 in the holding unit 413 is released, and the tablets 9 are delivered from the first transport conveyor 41 to the second transport conveyor 51. In addition, when passing from the 1st conveyance conveyor 41 to the 2nd conveyance conveyor 51, the front and back of the tablet 9 is reversed. Specifically, the back surface 92 of the tablet 9 that has been positioned on the first transport belt 412 side when being held by the first transport conveyor 41 is moved to the second transport belt 512 when being held by the second transport conveyor 51. It becomes the surface 91 located in the other side. Further, the surface 91 of the tablet 9 located on the opposite side of the first conveyor belt 412 when being held by the first conveyor 41 is located on the second conveyor belt 512 side when being held by the second conveyor 51. It becomes the back surface 92 located in.

  The first imaging unit 42 is located upstream of the first head unit 43 in the transport direction. The first imaging unit 42 generates image data of the tablet 9 by imaging the front surface 91 and the side surface 93 of the tablet 9 on the transport path by the first transport belt 412. The image data obtained in the first imaging unit 102 is transmitted to the control unit 70. Based on the received image data, the control unit 70 detects the presence / absence of the tablet 9 in each holding unit 413 and the position and orientation of the secant 90 of the tablet 9 held in the holding unit 413. The detailed configuration of the first imaging unit 42 will be described later.

  As described above, the tablets 9 are arranged on the first transport belt 412 at intervals in the width direction and the transport direction. In the present embodiment, three tablets 9 are arranged at intervals in the width direction of the first transport belt 412. FIG. 4 is a plan view illustrating the arrangement of the first imaging unit 42. As shown in FIG. 4, three first imaging units 42 are arranged at positions corresponding to the three tablets 9 in the width direction on the first transport belt 412. Each first imaging unit 42 images one tablet 9 in the width direction. In addition, each first imaging unit 42 sequentially images the plurality of tablets 9 conveyed in the conveyance direction. However, as shown in FIG. 4, in consideration of the arrangement space of the first imaging units 42, the three first imaging units 42 may be arranged with their positions shifted in the transport direction.

  The first head unit 43 is an ink jet head unit that discharges ink droplets toward the surface 91 of the tablet 9 that is conveyed by the first conveying conveyor 41. The first head unit 43 has four heads 431 arranged along the transport direction. The four heads 431 eject ink droplets of different colors (for example, cyan, magenta, yellow, and black) toward the surface 91 of the tablet 9. A multicolor image is printed on the surface 91 of the tablet 9 by superimposing single-color images formed by these colors. In addition, the edible ink manufactured from the raw material approved by the Japanese Pharmacopoeia, the Food Sanitation Law, etc. is used for the ink discharged from each head 431.

  FIG. 5 is a bottom view of one head 431. In FIG. 5, the first conveyor belt 412 and the plurality of tablets 9 held by the first conveyor belt 412 are indicated by two-dot chain lines. As shown enlarged in FIG. 5, a plurality of nozzles 430 capable of ejecting ink droplets are provided on the lower surface of the head 431. In the present embodiment, a plurality of nozzles 430 are two-dimensionally arranged on the lower surface of the head 431 in the transport direction and the width direction. The nozzles 430 are arranged at different positions in the width direction. Thus, if the plurality of nozzles 430 are two-dimensionally arranged, the positions in the width direction of the nozzles 430 can be brought closer to each other. However, the plurality of nozzles 430 may be arranged in a line along the width direction.

  As a method for ejecting ink droplets from the nozzle 430, for example, a so-called piezo method is used in which a voltage is applied to a piezo element to deform it to pressurize and eject the ink in the nozzle 430. However, the ink droplet discharge method may be a so-called thermal method in which the ink in the nozzle 430 is discharged by heating and energizing the heater.

  Returning to FIG. The first inspection camera 44 is an imaging unit for confirming the printing result by the first head unit 43. The first inspection camera 44 images the surface 91 of the tablet 9 that is transported to the first transport belt 412 on the downstream side of the first head unit 43 in the transport direction. Further, the first inspection camera 44 transmits the obtained image to the control unit 70. Based on the received image, the control unit 70 inspects whether or not the image printed on the surface 91 of each tablet 9 has a print defect such as a positional shift or a missing dot.

  The first fixing unit 45 is a mechanism that fixes the ink discharged from the first head unit 43 to the tablet 9. In the present embodiment, the first fixing unit 45 is disposed downstream of the first inspection camera 44 in the transport direction. However, the first fixing unit 45 may be disposed between the first head unit 43 and the first inspection camera 44. For the first fixing unit 45, for example, a hot air drying heater that blows hot air toward the tablets 9 conveyed by the first conveyance conveyor 41 is used. The ink attached to the surface 91 of the tablet 9 is dried by hot air and fixed to the surface 91 of the tablet 9.

  The second printing unit 50 is a processing unit for printing an image on the other surface of the tablet 9 after printing by the first printing unit 40. As shown in FIG. 1, the second printing unit 50 includes a second conveyor 51, a second imaging unit 52, a second head unit 53, a second inspection camera 54, a second fixing unit 55, and a defective product collecting unit 56. Have

  The second transport conveyor 51 transports while holding the plurality of tablets 9 delivered from the first transport conveyor 41. The second imaging unit 52 images the plurality of tablets 9 that are transported by the second transport conveyor 51 on the upstream side of the second head unit 53 in the transport direction. The second head unit 53 ejects ink droplets toward the surface 91 of the tablet 9 that is transported by the second transport conveyor 51. The second inspection camera 54 images the plurality of tablets 9 that are transported by the second transport conveyor 51 on the downstream side in the transport direction from the second head unit 53. The second fixing unit 55 fixes the ink discharged from each head 531 of the second head unit 53 to the tablet 9.

  The details of each of the second conveyor 51, the second imaging unit 52, the second head unit 53, the second inspection camera 54, and the second fixing unit 55 are as described above for the first conveyor 41 and the first imaging unit 42. Since it is equivalent to the first head unit 43, the first inspection camera 44, and the first fixing unit 45, duplicate description is omitted.

  The defective product collection unit 56 selects the tablet 9 determined to be defective based on the captured images obtained from the first imaging unit 42, the first inspection camera 44, the second imaging unit 52, and the second inspection camera 54. to recover. The defective product collection unit 56 includes a blow mechanism (not shown) disposed inside the second conveyor 51 and a collection box 561. When the tablet 9 determined to be a defective product is transported to the defective product recovery unit 56, the blow mechanism blows pressurized gas toward the tablet 9 from the inside of the second transport conveyor 51. As a result, the tablets 9 are dropped from the second conveyor 51 and are collected in the collection box 561.

  The carry-out conveyor 60 is a mechanism for carrying out the plurality of tablets 9 determined as non-defective products to the outside of the casing 100 of the printing apparatus 1. The upstream end of the carry-out conveyor 60 is located below the second pulley 511 of the second transport conveyor 51. The downstream end of the carry-out conveyor 60 is located outside the housing 100. For the carry-out conveyor 60, for example, a belt conveyance mechanism is used. The plurality of tablets 9 that have passed through the defective product collection unit 56 fall from the second transport conveyor 51 to the upper surface of the carry-out conveyor 60 by releasing the suction of the suction holes. Then, the plurality of tablets 9 are carried out of the housing 100 by the carry-out conveyor 60.

  The control unit 70 is means for controlling the operation of each unit in the printing apparatus 1. FIG. 6 is a block diagram illustrating connections between the control unit 70 and each unit in the printing apparatus 1. As conceptually shown in FIG. 6, the control unit 70 is configured by a computer having a processor 701 such as a CPU, a memory 702 such as a RAM, and a storage device 703 such as a hard disk drive. In the storage device 703, a computer program P and data D for executing a printing process and an inspection process are stored.

  As shown in FIG. 6, the control unit 70 includes the above-described linear feeder 21, the rotary feeder 22, the transport drum 30 (including a motor, a suction mechanism, and a blow mechanism), and a first transport conveyor 41 (a motor, a suction mechanism). , And a blow mechanism), a first imaging unit 42, a first head unit 43 (including a plurality of nozzles 430 of each head 431), a first inspection camera 44, a first fixing unit 45, a second conveyor 51 ( Motor, suction mechanism, and blow mechanism), second imaging unit 52, second head unit 53 (including a plurality of nozzles 430 of each head 531), second inspection camera 54, second fixing unit 55, defective product The collection unit 56 and the carry-out conveyor 60 are connected so as to be able to communicate with each other.

  The control unit 70 temporarily reads the computer program P and data D stored in the storage device 703 into the memory 702, and the processor 701 performs arithmetic processing based on the computer program P, thereby operating the above-described units. Control. Thereby, the printing process with respect to the some tablet 9 advances.

<2. Detailed Configuration of First Imaging Unit>
Next, the detailed configuration of the first imaging unit 42 will be described.

  FIG. 7 is a cross-sectional view illustrating a detailed configuration of the first imaging unit 42. In FIG. 7, the first conveying belt 412 that holds the tablets 9 imaged by the first imaging unit 42 and the two tablets 9 that are aligned with the tablets 9 in the width direction are indicated by two-dot chain lines. As shown in FIG. 7, the first imaging unit 42 includes a first imaging unit 102, a first optical system 103, a first on-axis illumination 106, and a plurality of first side illuminations 108.

  The first imaging unit 102 is an apparatus that generates image data of the tablet 9 by imaging the tablet 9. For the first imaging unit 102, for example, a CMOS camera is used. The first imaging unit 102 is located on the opposite side of the first transport belt 412 with respect to the plurality of tablets 9 transported by the first transport belt 412. In addition, the first imaging unit 102 includes a lens 102 </ b> A that receives the light guided to the first optical system 103. The first imaging unit 102 is attached to the upper surface of the housing 101 of the first imaging unit 42 in a manner in which the lens 102A is fitted into the hole 101A.

  The first optical system 103 includes a quadrangular pyramid mirror 103A and a plurality of reflection mirrors 103B. The quadrangular pyramid mirror 103A has a quadrangular pyramid-shaped three-dimensional shape, and includes the reflecting surfaces 104 on the upper three of the four side surfaces. Further, the quadrangular pyramid mirror 103 </ b> A is located at the lower part in the housing 101 and is disposed on the optical axis O of the first imaging unit 102. The quadrangular pyramid mirror 103 </ b> A reflects the light from the plurality of reflection mirrors 103 </ b> B with the reflection surface 104 on the side surface. In the present embodiment, the quadrangular pyramid mirror 103A is illustrated, but the shape of the mirror is not limited to the quadrangular pyramid, and may be another conical shape, for example, a conical mirror.

  The plurality of reflecting mirrors 103B are located at the lower part in the housing 101 and are disposed so as to surround the periphery of the quadrangular pyramid mirror 103A when viewed from the direction along the optical axis O of the first imaging unit 102. The reflecting surface 105 of each reflecting mirror 103B faces the surface 91 and the side surface 93 of the tablet 9 while being inclined.

  The light that reaches the reflecting surface 105 of the reflecting mirror 103B is reflected by the reflecting surface 105 and enters the reflecting surface 104 of the quadrangular pyramid mirror 103A. Further, the light is reflected by the reflecting surface 104 of the quadrangular pyramid mirror 103 </ b> A and guided to the lens 102 </ b> A of the first imaging unit 102. As described above, the end of the secant 90 is connected to the side surface 93 of the tablet 9. For this reason, even when the secant 90 is located on the back surface 92 of the tablet 9, the light reflected near the end of the secant 90 is reflected through the reflecting surface 105 of the reflecting mirror 103B and the reflecting surface 104 of the quadrangular pyramid mirror 103A. It is guided to the lens 102A of the first imaging unit 102.

  The elevation angle θ of each reflecting mirror 103B with respect to the tablet 9 is preferably greater than 0 degree and 30 or less, for example. In this way, even when there is a taper surface (chamfered portion) between the back surface 92 and the side surface 93 of the tablet 9, the end of the secant 90 positioned on the back surface 92 of the tablet 9 is passed through the reflection mirror 103B. Can be included in the field of view of the first imaging unit 102.

  At least one first on-axis illumination 106 is attached to the lower surface of the housing 101 and is disposed on or near the optical axis O of the first imaging unit 102. The quadrangular pyramid mirror 103 </ b> A is located between the first on-axis illumination 106 and the lens 102 </ b> A of the first imaging unit 102. The first on-axis illumination 106 mainly irradiates the surface 91 of the tablet 9 that faces the first on-axis illumination 106.

  The plurality of first side lights 108 are positioned below the housing 101 and at least around the first on-axis light 106 and the tablet 9 when viewed from the direction along the optical axis O of the first imaging unit 102. A part of the ring is arranged around the ring. Each first side illumination 108 mainly irradiates light on the surface 91 and the side surface 93 of the tablet 9 that face the first side illumination 108. Each of the first side lights 108 is arranged so that the inclination angle of the optical axis is about 60 degrees or more and 90 degrees or less with respect to the side surface 93 of the tablet 9. Note that the first side illumination 108 may be formed integrally with the housing 101.

  As shown in FIG. 7, the first on-axis illumination 106 and the plurality of first side illuminations 108 are reflected from the tablet 9, and the lens 102A of the first imaging unit 102 is reflected via the reflection mirror 103B and the quadrangular pyramid mirror 103A. Arranged while avoiding the path of light guided to. That is, by having the first optical system 103, the light reflected from the tablet 9 irradiated with light from the first on-axis illumination 106 and the plurality of first side illuminations 108 is bypassed by the first on-axis illumination 106. Meanwhile, the light can be condensed on the lens 102 </ b> A of the first imaging unit 102.

  The first imaging unit 102 images the surface 91 and the side surface 93 of the tablet 9 irradiated with light by a plurality of irradiation patterns using the first on-axis illumination 106 and the plurality of first side illuminations 108. Further, the plurality of reflection mirrors 103B surround the periphery of the tablet 9 as viewed from the direction along the optical axis O of the first imaging unit 102, and are arranged at different positions in the circumferential direction. Thereby, the 1st imaging part 102 can acquire the image which imaged the surface 91 and the side surface 93 of the tablet 9 from two or more directions which are mutually different in the circumferential direction via several reflective mirror 103B. As a result, it is possible to accurately detect the direction of the dividing line 90 on the back surface 92.

  It should be noted that at least two of the plurality of reflection mirrors 103B are desirably arranged at positions shifted from each other by about 90 degrees in the circumferential direction when viewed from the direction along the optical axis O of the first imaging unit 102. Thereby, the 1st imaging part 102 can acquire the image which imaged the surface 91 and the side surface 93 of the tablet 9 from 2 directions which shifted | deviated 90 degree | times to the circumferential direction mutually. As a result, it is possible to acquire an image in which the end of the dividing line 90 is captured regardless of the orientation of the dividing line 90.

  In addition, it is desirable that at least two of the plurality of reflection mirrors 103B are arranged at positions shifted from each other by about 180 degrees in the circumferential direction when viewed from the direction along the optical axis O of the first imaging unit 102. Thereby, the 1st imaging part 102 can acquire the image which imaged the surface 91 and the side surface 93 of the tablet 9 from 2 directions mutually shifted | deviated 180 degree | times to the circumferential direction. As a result, even when the tablet 9 is conveyed in a state inclined with respect to the horizontal plane, and the dividing line 90 is inclined with respect to the horizontal plane, an image in which the end portion of the dividing line 90 is captured can be acquired.

  Further, in the present embodiment, the tablet 9 is imaged by the first imaging unit 42 in a state where the tablet 9 is raised by the holding unit 413 from the first conveyance belt 412. For this reason, the light emitted from the plurality of first side lights 108 easily reaches the back surface 92 of the tablet 9. As a result, it is possible to acquire an image captured more clearly over the entire surface 91 and side surface 93 of the tablet 9.

<3. Data processing in the control unit>
FIG. 8 is a block diagram conceptually showing part of the function of the control unit 70. As shown in FIG. 8, the control unit 70 of the present embodiment includes a first secant detection unit 711, a second secant detection unit 712, a first head control unit 721, a second head control unit 722, a first inspection unit 731, And a second inspection unit 732. The function of each unit is as follows. The computer program P and data D stored in the storage device 703 of the control unit 70 are temporarily read into the memory 702, and the processor 701 performs arithmetic processing based on the computer program P. Realized.

  The first secant detection unit 711 and the second secant detection unit 712 have a secant 90 position (whether the secant 90 is on the front surface 91 of the tablet 9 or the back surface 92 of the tablet 9) and direction of each tablet 9 being conveyed. It is a function for detecting. First, the first secant detection unit 711 will be described. The first dividing line detection unit 711 includes a first front surface dividing line detection unit 81 and a first back surface dividing line detection unit 82.

  The first surface secant detection unit 81 first has a secant 90 on the surface 91 of each tablet 9 conveyed by the first conveyor 41 based on the image data generated by the first imaging unit 102 of the first imaging unit 42. Detect whether or not there is. And when it detects that there is a secant 90 on the surface 91 of the tablet 9, the direction is detected. More specifically, the 1st surface secant detection part 81 detects whether the surface 91 has the secant 90 by image-analyzing the area | region of the surface 91 of the tablet 9 in image data. When it is detected that there is a secant line 90 on the surface 91, the direction of the secant line 90 on the surface 91 (for example, the rotation angle of the secant line 90 with respect to the conveyance direction of the tablet 9) is detected by further analyzing the image data.

  The first back surface dividing line detection unit 82 first has a dividing line 90 on the back surface 92 of each tablet 9 conveyed by the first conveyance conveyor 41 based on the image data generated by the first imaging unit 102 of the first imaging unit 42. Detect whether or not there is. And when it detects that the secant 90 is in the back surface 92 of the tablet 9, the direction is detected. More specifically, the first back surface dividing line detection unit 82 performs image analysis on the region of the side surface 93 of the tablet 9 in the image data, and determines whether or not the end of the dividing line 90 appears on the side surface 93 of the tablet 9. By detecting, it is detected whether or not there is a secant 90 on the back surface 92 of the tablet 9. Then, when it is detected that the dividing line 90 is present on the back surface 92, the direction of the dividing line 90 on the back surface 92 (for example, with respect to the transport direction of the tablet 9) is further determined based on the position of the end of the dividing line 90 that appears on the side surface 93 of the tablet 9. The rotation angle of the secant 90) is detected. As described above, the secant 90 extends straight through the center of the secant plane of the tablet 9 to both ends. Therefore, the orientation of the dividing line 90 can be detected by analyzing the image data and detecting the center position of the back surface 92 and the position of the end of at least one dividing line 90 appearing on the side surface 93.

  The first back surface dividing line detection unit 82 detects whether the dividing line 90 is formed on the back surface 92 of the tablet 9 based on the result of detecting whether the first surface dividing line detection unit 81 has the dividing line 90 on the surface 91 of the tablet 9. It may be detected whether or not there is. For example, when the first surface secant detection unit 81 detects that there is no secant 90 on the surface 91 of the tablet 9, the first back secant detector 82 detects that there is a secant 90 on the back 92 of the tablet 9. Also good.

  Similarly, the second dividing line detection unit 712 determines whether there is a dividing line 90 on the front surface 91 or the back surface 92 of each tablet 9 conveyed by the second conveyance conveyor 51 based on the image data generated by the second imaging unit 52. To detect. If it is detected that there is a secant line 90, the position (whether the secant line 90 is on the front surface 91 of the tablet 9 or the back surface 92 of the tablet 9) and the direction (for example, the secant line 90 with respect to the conveyance direction of the tablet 9). ) Is detected. The details of the second secant detection unit 712 are the same as those of the first secant detection unit 711 described above, and thus the duplicate description is omitted.

  As described above, the plurality of tablets 9 respectively transported by the first transport conveyor 41 and the second transport conveyor 51 are held from the secant surface side having the secant line 90 (the secant line 90 is not exposed to the imaging unit side). 9 and the tablet 9 held from the main surface side not having the secant line 90 (the secant line 90 is exposed to the imaging unit side) are mixed. On the other hand, the front and back of the tablet 9 are reversed when the first transport conveyor 41 is transferred to the second transport conveyor 51. In the present embodiment, since the first secant detection unit 711 and the second secant detection unit 712 have the above-described configuration, the positions and orientations of the secant 90 of all the tablets 9 can be detected. In the present embodiment, the position and orientation of the secant 90 on the front surface 91 or the back surface 92 of the tablet 9 can be detected in each of the first imaging unit 42 and the second imaging unit 52. As a result, the number of imaging units for detecting the position and orientation of the secant 90 can be minimized. As a result, the arrangement space and cost of the imaging unit in the printing apparatus 1 are reduced.

  The first head control unit 721 is a function for controlling the operation of the first head unit 43. The first head control unit 721 has a first storage unit 83. The second head control unit 722 is a function for controlling the operation of the second head unit 53. The second head control unit 722 has a second storage unit 84. The functions of the first storage unit 83 and the second storage unit 84 are realized by the storage device 703 described above, for example. The first storage unit 83 and the second storage unit 84 store print image data D1. In the present embodiment, an image is printed only on the main surface of the main surface and the secant surface of the tablet 9. The print image data D1 is data representing an image to be printed on the main surface of the tablet 9. The image includes a product name, a product code, a company name, a logo mark, and the like, and is formed by a character string including alphabets and numbers, for example. The first storage unit 83 and the second storage unit 84 may be a single storage unit.

  When printing on the tablet 9, first, the first head control unit 721 reads the print image data D <b> 1 from the first storage unit 83. Subsequently, the first head control unit 721 rotates the read print image data D1 based on the direction (rotation angle) of the dividing line 90 of the back surface 92 of the tablet 9 detected by the first dividing line detection unit 711. . Then, the first head control unit 721 controls the head 431 of the first printing unit 40 based on the rotated print image data D1. Then, the image represented by the print image data D <b> 1 is printed on the front surface 91 of the tablet 9 transported to the first transport conveyor 41 along the dividing line 90 of the back surface 92.

  Thereby, after detecting the position and orientation of the dividing line 90 of the tablet 9, printing can be performed along the direction of the detected dividing line 90 without changing the direction in which the tablet 9 is held. As a result, it is possible to suppress a shift between the direction of the dividing line 90 and the print image. That is, it is possible to print at a more accurate position and orientation with respect to the direction of the dividing line 90.

  In the present embodiment, when the main surface of the tablet 9 that does not have the secant line 90 faces the front surface 91, an image is displayed on the front surface 91 that is the main surface while avoiding a portion that faces the secant line 90 of the rear surface 92. Print. That is, the first printing unit 40 prints on the front surface 91 of the tablet 9 based on the direction of the dividing line 90 of the back surface 92 detected by the first back surface dividing line detection unit 82. However, when the secant surface having the secant line 90 faces the surface 91, the image may be printed on the surface 91 that is the secant surface while avoiding the secant line 90. That is, the first printing unit 40 may print on the surface 91 of the tablet 9 based on the direction of the dividing line 90 detected by the first surface dividing line detection unit 81. The print image data D1 also includes information for designating the print position and print direction of the image on the tablet 9 as described above.

  Similarly, the second head control unit 722 controls the head 531 of the second printing unit 50. Thereby, the image represented by the print image data D <b> 1 is printed on the front surface 91 of the tablet 9 transported to the second transport conveyor 51 along the dividing line 90 of the back surface 92. As a result, the printing along the dividing line 90 on the main surface of all the tablets 9 is completed.

  The first inspection unit 731 is a function for detecting a defect in an image printed on the surface 91 of the tablet 9 conveyed by the first conveyance conveyor 41. As illustrated in FIG. 8, the first inspection unit 731 includes a third storage unit 85. The function of the 3rd memory | storage part 85 is implement | achieved by the memory | storage device 703 mentioned above, for example. The third storage unit 85 stores the inspection image data D2. The inspection image data D2 is the same as the print image data D1.

  When inspecting the tablet 9 after printing, the first inspection unit 731 reads out inspection image data D2 for inspection from the third storage unit 85. Then, the first inspection unit 731 rotates the read inspection image data D2 in accordance with the direction (rotation angle) of the secant 90 detected by the first secant detector 711. In addition, the first inspection unit 731 acquires the captured image data Dp of the tablet 9 after printing from the first inspection camera 44. The first inspection unit 731 compares the rotated print image data D1 for inspection with the captured image data Dp acquired from the first inspection camera 44, thereby comparing the image printed on the surface 91 of the tablet 9. Detect defects. Specifically, if there is a difference greater than or equal to a preset threshold value between the print image data D1 and the captured image data Dp, the portion is detected as a defect.

  Similarly, the second inspection unit 732 detects a defect in the image printed on the surface 91 of the tablet 9 conveyed by the second conveyance conveyor 51. As a result, the inspection of the printing state on all the tablets 9 is completed. In addition, the 4th memory | storage part 86 and the 3rd memory | storage part 85 which the 2nd test | inspection part 732 has may be a single memory | storage part.

  As described above, the printing method of the present embodiment is a printing method in which an image is printed on the front surface 91 of the tablet 9 that is a granular material by an inkjet method, and a) a step of transporting the tablet 9 while holding it from the back surface 92 side. And b) on the basis of the image data generated in step b), a step of generating image data of the tablet 9 by imaging the surface 91 and the side surface 93 of the tablet 9 in the middle of the step a). Detecting whether or not the dividing line 90 is on the back surface 92, and detecting the direction of the dividing line 90 on the back surface 92; and d) based on the direction of the dividing line 90 detected in step c). And printing on the surface 91 of the tablet 9. Thereby, after detecting the position and orientation of the dividing line 90 of the tablet 9, printing can be performed along the direction of the detected dividing line 90 without changing the direction in which the tablet 9 is held. As a result, it is possible to suppress the occurrence of deviation in the direction of the dividing line 90, and to print with a more accurate position and orientation with respect to the direction of the dividing line 90.

<4. Modification>
As mentioned above, although main embodiment of this invention was described, this invention is not limited to said embodiment.

  In the above embodiment, according to the orientation (rotation angle) of the tablet 9 detected by the first secant detection unit 711 and the second secant detection unit 712, the first inspection unit 731 and the second inspection unit 732 are inspection images. Data D2 was rotated. However, a plurality of inspection image data D2 having different rotation angles (for example, 360 inspection image data D2 having different rotation angles by 1 °) are stored in advance in the third storage unit 85 and the fourth storage unit 86. Also good. And the 1st inspection part 731 and the 2nd inspection part 732 are the inspection image data D2 according to the direction (rotation angle) of the tablet 9 detected in the 1st secant detection part 711 or the 2nd secant detection part 712, respectively. The inspection may be performed by reading from the third storage unit 85 or the fourth storage unit 86.

  In this way, the calculation burden on the first inspection unit 731 and the second inspection unit 732 can be reduced as compared with the case where the inspection image data D2 is rotated one by one for each tablet 9. Accordingly, the inspection of the printed image can be executed quickly.

  Moreover, said printing apparatus 1 was an apparatus which prints on the main surface which does not have the secant 90 of the tablet 9 by the 1st printing part 40 and the 2nd printing part 50. FIG. However, the printing apparatus of the present invention may be an apparatus that performs printing on both sides of the tablet 9. Further, the printing apparatus of the present invention may be an apparatus that performs printing only on the secant plane having the secant line 90 of the tablet 9.

  In the above embodiment, the first printing unit 40 and the second printing unit 50 are each provided with four heads. However, the number of heads included in each of the first printing unit 40 and the second printing unit 50 may be 1 to 3, or 5 or more.

  Further, the “particulate matter” to be processed in the present invention is not limited to the tablet 9 appearing in the above embodiment. The “particulates” may be capsules including, for example, uncoated tablets (bare tablets), orally disintegrating tablets (OD tablets), film-coated tablets (FC tablets), sugar-coated tablets, hard capsules, and soft capsules. . The printing apparatus of the present invention is not limited to tablets as pharmaceuticals, and may print on tablets as health foods and tablet confectionery such as ramune.

  Further, the detailed configuration of the printing apparatus 1 may be different from those in the drawings 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 Printing apparatus 9,9X Tablet 10 Hopper 20 Feeder part 30 Conveyance drum 40 1st printing part 41 1st conveyance conveyor 42 1st imaging unit 43 1st head unit 44 1st inspection camera 45 1st fixing | fixed part 50 2nd printing part 51 Second Conveyor 52 Second Imaging Unit 53 Second Head Unit 54 Second Inspection Camera 55 Second Fixing Unit 56 Defective Product Recovery Unit 60 Unloading Conveyor 70 Control Unit 81 First Surface Split Line Detection Unit 82 First Back Side Split Line Detection Unit 90, 90X secant 91 91 front surface 92 back surface 93 side surface 100 housing 102 first imaging unit 103 first optical system 103A quadrangular pyramid mirror 103B reflection mirror 104 reflection surface 105 reflection surface 106 first axial illumination 108 first side illumination 412 second 1 Conveyor belt 413 Holding part O Optical axis

Claims (11)

A printing apparatus that prints an image on the surface of a granular material by an inkjet method,
A transport mechanism for transporting the granular material from the back side;
An imaging unit that generates image data of the granular material by imaging the surface and side surfaces of the granular material conveyed by the conveying mechanism;
Based on the image data, detecting whether or not there is a secant on the back surface, and detecting the direction when the secant is on the back surface,
Based on the direction of the dividing line detected by the back surface dividing line detection unit, a printing unit that prints on the surface of the granular material;
Having a printing device. The printing apparatus according to claim 1,
The back surface dividing line detection unit detects a direction of the dividing line on the back surface based on a position of an end of the dividing line that appears on the side surface of the granular material in the image data. The printing apparatus according to claim 1 or 2, wherein
A plurality of lights capable of irradiating the granular material with light;
The plurality of lights are:
A plurality of side illuminations arranged to surround at least a part of the granular material as seen from the direction along the optical axis of the imaging unit;
At least one on-axis illumination disposed on the optical axis of the imaging unit;
Including
The printing apparatus includes:
An optical system that guides the light reflected by the granular material irradiated with light by the on-axis illumination to the imaging unit while bypassing the on-axis illumination;
The said imaging part is a printing apparatus which images the said surface and the said side surface of the said granular material with which light was irradiated by the several irradiation pattern using the said some side illumination and the said on-axis illumination. The printing apparatus according to claim 3,
The optical system is
A plurality of reflecting mirrors each having a reflecting surface that is inclined and opposed to the surface and the side surface of the granular material;
The said imaging part is a printing apparatus which images the said side surface of the said granular material from two or more directions which are mutually different in the circumferential direction through the said several reflective mirror. The printing apparatus according to claim 4,
The imaging unit is a printing apparatus that images the side surface of the granular material from two directions that are shifted from each other by 90 degrees in the circumferential direction. The printing apparatus according to claim 4,
The image pickup unit picks up the side surface of the granular material from two directions that are 180 degrees apart from each other in the circumferential direction. The printing apparatus according to claim 3,
The optical system is
A reflecting mirror having a reflecting surface that is inclined and opposed to the surface and the side surface of the granular material;
The elevation angle with respect to the granular material of the reflection mirror is greater than 0 degree and 30 degrees or less. The printing apparatus according to any one of claims 1 to 7,
Based on the image data, a surface dividing line detection unit that detects whether the surface has the dividing line, and detects the direction when the surface has the dividing line,
The printing unit prints on the surface of the granular material based on the direction of the dividing line detected by the surface dividing line detection unit. A printing apparatus according to any one of claims 1 to 8, wherein
The transport mechanism is
A first conveyor belt that conveys the granular material while adsorbing the back surface;
The imaging unit is a printing apparatus that images the surface and the side surface of the granular material on a conveyance path by the first conveyance belt. The printing apparatus according to claim 9, wherein
The image pickup unit is a printing apparatus that is located on the opposite side of the first conveyance belt with respect to the granular material. A printing method for printing an image on the surface of a granular material by an inkjet method,
a) transporting the granular material while holding it from the back side;
b) generating image data of the granular material by imaging the surface and side surfaces of the granular material in the middle of the step a);
c) detecting whether there is a secant on the back surface based on the image data generated in the step b), and detecting the orientation when the secant is on the back surface;
d) printing on the surface of the granular material based on the direction of the secant detected in step c);
A printing method.

Images