WO2019159426A1 - Inspection device, inspection method, tablet printing device, and tablet printing method - Google Patents

Abstract

The present invention improves the accuracy of image-capturing-based visual inspection of a target object. An inspection device according to the present invention is provided with: at least one light (106, 108) that is capable of irradiating a target object (2) with light; an image capturing unit (102) that captures an image of the target object irradiated with light by the light and that generates image data of the target object; and an inspection unit (3) that performs visual inspection of the target object on the basis of the image data of the target object. When a direction slanted in a first direction from the direction along the optical axis of the image capturing unit that captures the image of the target object is considered as a first irradiation direction and a direction slanted in a second direction, which is opposite to the first direction, from the direction along the optical axis of the image capturing unit is considered as a second irradiation direction, the amount of light with which the target object is irradiated by the light along the first irradiation direction is greater than the amount of light with which the target object is irradiated by the light along the second irradiation direction.

Description

Inspection device, inspection method, tablet printing device, and tablet printing method

This invention disclosed in this specification relates to, for example, tablet inspection and printing technology.

Conventionally, an appearance inspection of an object such as a tablet has been performed by performing predetermined image processing on image data obtained by imaging the object and determining the quality of the appearance (for example, Patent Document 1). See).

JP 2007-114180 A

In the conventional method, the object is imaged in a state where the object is uniformly irradiated with light. For this reason, when there is a relatively shallow scratch on the object, it may be difficult to determine on the image data.

The present invention disclosed in the specification of the present application has been made to solve the above-described problems, and is intended to improve the accuracy of inspection in an appearance inspection of an object using an image obtained by imaging. The purpose is to provide the technology.

According to a first aspect of the technology disclosed in the specification of the present application, at least one illumination capable of irradiating light on an object, imaging the object irradiated with light by the illumination, and imaging of the object An imaging unit that generates image data, and an inspection unit that performs an appearance inspection of the object based on the image data of the object, and from a direction along the optical axis of the imaging unit that images the object The direction inclined in the first direction is the first irradiation direction, and the direction inclined in the second direction opposite to the first direction from the direction along the optical axis of the imaging unit is the second irradiation. The amount of light that the illumination irradiates the object along the first irradiation direction is greater than the amount of light that the illumination irradiates the object along the second irradiation direction.

A second aspect of the technology disclosed in the specification of the present application relates to the first aspect, and the illumination surrounds at least a part of the object when viewed from a direction along the optical axis of the imaging unit. It includes a plurality of side lights arranged.

A third aspect of the technology disclosed in the specification of the present application relates to the second aspect, and the plurality of side illuminations surround the object when viewed from a direction along the optical axis of the imaging unit. As viewed from the direction along the optical axis of the imaging unit, only one of the pair of side lights sandwiching the object irradiates the object with light.

A fourth aspect of the technology disclosed in the specification of the present application relates to any one of the first to third aspects, and the illumination is disposed on the optical axis of the imaging unit. And an optical system that guides light reflected by the object irradiated with light from the upper illumination to the imaging unit while bypassing the upper illumination.

A fifth aspect of the technology disclosed in the specification of the present application relates to the fourth aspect, and the illumination is disposed so as to surround at least a part of the object when viewed from a direction along the optical axis of the imaging unit. The plurality of side illuminations are arranged within a range in which the optical system is arranged when viewed from a direction along the optical axis of the imaging unit.

A sixth aspect of the technology disclosed in the present specification is related to any one of the first to fifth aspects, and the first irradiation direction is from the imaging unit in a plan view. The second irradiation direction is a direction extending from the periphery of the imaging unit toward the optical axis in plan view.

A seventh aspect of the technology disclosed in the specification of the present application relates to any one of the first to sixth aspects, and the illumination is from a direction along the optical axis of the imaging unit. As seen, it includes a plurality of side illuminations arranged at least partially surrounding the object, and at least one upper illumination arranged on the optical axis of the imaging unit, and the light by the upper illumination The optical system further includes an optical system that guides the light reflected by the object irradiated to the imaging unit while bypassing the upper illumination, and the imaging unit uses a plurality of the side illuminations and a plurality of the upper illuminations. The object irradiated with light according to the irradiation pattern is imaged, and image data of the object is generated.

An eighth aspect of the technology disclosed in the specification of the present application relates to any one of the first aspect to the seventh aspect, and relates to the inspection apparatus and the tablet inspected by the inspection apparatus. A printing unit that performs printing.

According to a ninth aspect of the technology disclosed in the specification of the present application, a step of imaging an object irradiated with light by at least one illumination and generating image data of the object; A step of performing an appearance inspection of the object based on image data, and a direction inclined in a first direction from a direction along an optical axis of an imaging unit that images the object is a first irradiation direction, The direction inclined from the direction along the optical axis of the imaging unit to the second direction opposite to the first direction is defined as a second irradiation direction, and the illumination is along the first irradiation direction. The amount of light that irradiates the object is greater than the amount of light that the illumination irradiates the object along the second irradiation direction.

The tenth aspect of the technique disclosed in this specification is related to the ninth aspect, and includes a step of printing on the tablet inspected by the above inspection method.

According to the first and ninth aspects of the technology disclosed in the specification of the present application, the accuracy of image recognition is increased by increasing the difference in gradation in image data, and the accuracy of appearance inspection of an object by imaging is increased. be able to.

In particular, according to the second aspect, the side illumination makes it possible to irradiate light from only one direction around the object, so that even a relatively shallow defect can be easily detected. it can.

Particularly, according to the third aspect, light is emitted from only one direction around the object by partially lighting the side illumination surrounding the object as viewed from the direction along the optical axis. By doing so, even a relatively shallow defect can be easily detected.

In particular, according to the fourth aspect, the amount of light irradiated radially on the main surface of the object by the upward illumination is higher than the amount of light irradiated from the periphery of the object toward the object. Therefore, the difference between the gradation on the main surface of the object and the gradation on the side surface becomes large, and a relatively shallow defect or the like can be easily detected by image processing.

Particularly, according to the fifth aspect, since the structure of the inspection apparatus can be reduced, the inspection apparatuses can be easily arranged closely.

In particular, according to the sixth aspect, when the upper illumination and the side illumination are used in combination, the amount of light irradiated radially from the upper illumination is the side illumination that surrounds the object as seen from the direction along the optical axis. Therefore, the difference between the gradation on the main surface of the object and the gradation on the side surface becomes large.

Particularly, according to the seventh aspect, since the object can be irradiated with a plurality of irradiation patterns using upper illumination and side illumination, the inspection accuracy can be improved.

In particular, according to the eighth and tenth aspects, since printing is performed only on an object that has been visually inspected with high accuracy, the object having foreign matter, scratches, defects, or the like is collected as a non-defective product. Can be prevented.

The objectives, features, aspects, and advantages of the technology disclosed in the present specification will become more apparent from the detailed description and the accompanying drawings shown below.

1 is a diagram schematically illustrating an overall configuration of a tablet printing apparatus according to an embodiment. It is a perspective view which shows the external appearance of a conveyance drum and a conveyance belt. It is sectional drawing which illustrates the specific structure of an imaging unit. It is a figure at the time of looking up at an imaging unit from the Z-axis negative direction. It is a top view which illustrates arrangement | positioning of the imaging unit in an external appearance inspection unit. It is a flowchart which shows the procedure of the processing operation in a tablet printer. It is a flowchart which shows the procedure of the processing operation in a tablet printer. It is a top view of a tablet. It is a figure which shows an example of the imaging result by an imaging unit. It is a figure which shows an example of the image data imaged with the 1st irradiation pattern. It is a figure which shows an example of the image data imaged in the state which set so that the light quantity which an upper illumination irradiates a tablet and the light quantity which a ring-shaped side illumination irradiates a tablet may become equal. It is a conceptual diagram which illustrates the light irradiated to the comparatively shallow defect formed in the 1st surface of a tablet. It is a conceptual diagram which illustrates the light irradiated to the comparatively shallow defect formed in the 1st surface of a tablet. It is a figure which shows the other example of the image data imaged with the 2nd irradiation pattern. It is a figure which shows an example of the image data imaged in the state which turned off the upper illumination and turned on the circumference of the ring-shaped side illumination. It is a figure which shows an example of the printing process result by an inkjet head.

Hereinafter, embodiments will be described with reference to the accompanying drawings.

It should be noted that the drawings are schematically shown, and the configuration is omitted or simplified as appropriate for the convenience of explanation. In addition, the mutual relationships between the sizes and positions of the configurations and the like shown in different drawings are not necessarily accurately described and can be changed as appropriate.

In the following description, the same components are denoted by the same reference numerals, and the names and functions thereof are also the same. Therefore, detailed descriptions thereof may be omitted to avoid duplication.

In the description described below, a specific position and direction such as “top”, “bottom”, “left”, “right”, “side”, “bottom”, “front” or “back” Even if the meaning terms are used, these terms are used for convenience to facilitate understanding of the contents of the embodiment, and have no relation to the direction in actual implementation. It is something that does not.

In addition, in the description described below, even if an ordinal number such as “first” or “second” is used, these terms mean that the contents of the embodiment are understood. It is used for the sake of convenience, and is not limited to the order that can be generated by these ordinal numbers.

<Embodiment>
<About the configuration of the tablet printing device>
FIG. 1 is a diagram schematically illustrating an overall configuration of a tablet printing apparatus according to the present embodiment. As illustrated in FIG. 1, the tablet printing apparatus 1 is an apparatus that performs a printing process on both the front and back surfaces of a tablet.

The tablet printing apparatus 1 includes at least a hopper 8, a conveyance drum 10, a conveyance belt 20, a conveyance belt 30, an appearance inspection camera 51, an appearance inspection unit 52, an appearance inspection unit 53, an inkjet head 61, An inkjet head 62 is provided. The tablet printing apparatus 1 also includes a control unit 3 that controls each drive unit provided in the apparatus to advance the inspection process and the printing process for the tablet.

The hopper 8 is provided on the upper side of the ceiling of the housing 5 of the tablet printing apparatus 1. The hopper 8 is an input unit for supplying a large number of tablets into the apparatus at once. The plurality of tablets input from the hopper 8 flows into the rectilinear feeder 122 along the inclined surface. The plurality of tablets supplied to the rectilinear feeder 122 are conveyed to the rotary feeder 123 side by the vibration of the vibration trough. And it gathers to the outer peripheral part vicinity of a turntable with the centrifugal force by rotation of a turntable in the rotation feeder 123. FIG. Then, the tablets gathered near the outer periphery of the turntable are supplied to the transport drum 10 by a supply feeder 124 extending vertically downward from the outer periphery of the turntable to the transport drum 10.

FIG. 2 is a perspective view showing the appearance of the transport drum 10 and the transport belt 20. The conveyance drum 10 has a substantially cylindrical shape, and is rotated clockwise around a central axis along the Y-axis direction by a rotation drive motor (not shown here). As illustrated in FIG. 2, a plurality of suction holes 11 are formed on the outer peripheral surface of the transport drum 10. In the present embodiment, the suction holes 11 are formed in five rows at equal intervals along the central axis of the transport drum 10. Further, a set of suction holes 11 in five rows is provided in a plurality of rows at equal intervals along the circumferential direction of the outer peripheral surface of the transport drum 10.

The shape of the suction hole 11 is in accordance with the shape of the object to be inspected and printed. For example, in the present embodiment, since the disk-shaped tablet is processed, the shape of the suction hole 11 is also circular. The size of the suction hole 11 is slightly larger than the size of the tablet. For example, if the diameter of the disc-shaped tablet is about 10 mm, the diameter of the suction hole 11 is about 12 mm.

Small holes smaller than the suction holes 11 are provided at the bottoms of the plurality of suction holes 11, and each of the plurality of suction holes 11 is provided with a suction mechanism (here, provided inside the transport drum 10 through the small holes). (Not shown). By operating the suction mechanism, a negative pressure lower than the atmospheric pressure can be applied to each of the plurality of suction holes 11. As a result, each suction hole 11 of the transport drum 10 can suck and hold one tablet.

Further, a blow mechanism is provided in the vicinity of the portion facing the conveyor belt 20 inside the conveyor drum 10. The blow mechanism blows pressurized air toward the small hole provided at the bottom of the suction hole 11. When the blow mechanism blows air to the small holes, a pressure higher than the atmospheric pressure can be applied to the adsorption holes 11. Thereby, the adsorption state of the tablet by the adsorption hole 11 can be cancelled | released. As described above, the suction holes 11 provided on the transport drum 10 are all sucked by the suction mechanism, and the suction holes 11 in the fifth row and the first row facing the transport belt 20 are blown. Adsorption can be released by the mechanism.

The conveying belt 20 is configured by a plurality of holding plates 22 connected in a belt shape and stretched around a pair of pulleys. When the pair of pulleys are rotationally driven by a drive motor (not shown here), the belt-like body composed of the plurality of holding plates 22 moves in the direction of the arrow in FIG. The conveyor belt 20 is installed such that a part of a belt-like body composed of a plurality of holding plates 22 is opposed to the outer peripheral surface of the conveyor drum 10.

2, a plurality of suction holes 21 are formed in each of the plurality of holding plates 22 at equal intervals along the width direction of the belt (Y-axis direction). In the present embodiment, the suction holes 21 are formed in each holding plate 22 in five rows along the Y-axis direction. The shape and size of the suction holes 21 of the transport belt 20 are the same as the suction holes 11 of the transport drum 10. Further, the spacing between the suction holes 21 arranged in five rows on each holding plate 22 is also equal to the spacing between the suction holes 11 arranged in five rows along the central axis of the transport drum 10.

Similar to the suction holes 11, small holes smaller than the suction holes 21 are provided at the bottoms of the plurality of suction holes 21, and each of the plurality of suction holes 21 passes through the small holes and enters the inside of the conveying belt 20. It communicates with a provided suction mechanism. By operating the suction mechanism, a negative pressure lower than the atmospheric pressure can be applied to each of the plurality of suction holes 21. As a result, each suction hole 21 of the transport belt 20 can hold one tablet by suction.

In addition, a blow mechanism is provided in the vicinity of a portion facing the below-described conveyance belt 30 inside the conveyance belt 20. The blow mechanism blows pressurized air toward the small hole provided at the bottom of the suction hole 21. When the blow mechanism blows air into the small holes, a pressure higher than the atmospheric pressure can be applied to the adsorption holes 21. Thereby, the adsorption state of the tablet by the adsorption hole 21 can be canceled.

The configuration of the conveyor belt 30 is substantially the same as that of the conveyor belt 20. That is, the conveyance belt 30 is configured by a plurality of holding plates connected in a belt shape and stretched over a pair of pulleys. When the pair of pulleys are rotationally driven by the drive motor, the conveyor belt 30 moves in the direction of the arrow in FIG. The conveyor belt 30 is installed such that a part of a belt-like body composed of a plurality of holding plates faces the conveyor belt 20 in the vicinity.

The holding plate of the conveyance belt 30 is also formed with a plurality (five rows in this embodiment) of suction holes at equal intervals along the belt width direction (Y-axis direction).

Similarly to the above, a negative pressure lower than the atmospheric pressure can be applied to the suction holes of the conveyor belt 30 by the suction mechanism provided inside the conveyor belt 30. Thereby, each suction hole of the conveyance belt 30 can hold one tablet by suction. Moreover, the blow mechanism is provided in the inside of the conveyance belt 30, for example over three places. When the blow mechanism blows air, a pressure higher than the atmospheric pressure is applied to the suction hole of the transport belt 30 to release the tablet adsorption state by the suction hole.

All three blow mechanisms of the transport belt 30 blow air downward or diagonally downward. Therefore, among the three blow mechanisms, a blow mechanism provided at a portion facing the non-defective duct 48 blows air, thereby releasing the tablet adsorption state by the suction holes and releasing the tablets to the non-defective duct 48. be able to. The tablets released into the good product duct 48 are collected in the good product collection box 58.

Further, when a blow mechanism provided at a portion facing the defective appearance product duct 47 blows air, the tablet can be released from the suction holes and released to the defective appearance product duct 47. The tablets released to the defective appearance duct 47 are collected in the defective appearance box 57.

Furthermore, when a blow mechanism provided at a portion facing the defective print duct 46 blows air, the tablet adsorption state by the suction holes can be released and the tablet can be discharged to the defective print duct 46. The tablets released to the defective print duct 46 are collected in the defective print box 56.

The appearance inspection camera 51 is an imaging unit for imaging a predetermined area, and is, for example, a CMOS camera or a CCD camera.

The appearance inspection camera 51 is installed facing the outer peripheral surface so that the imaging area becomes the outer peripheral surface of the transport drum 10.

The appearance inspection camera 51 images a plurality of tablets conveyed while being sucked and held in the suction holes 11 of the transport drum 10. The size of the imaging area of the appearance inspection camera 51 can be set as appropriate, but since the cylindrical peripheral surface of the transport drum 10 is imaged, focusing over a wide range of the cylindrical peripheral surface is not possible. Have difficulty. For this reason, the imaging area of the appearance inspection camera 51 only needs to be large enough to image at least 5 columns and 1 row of tablets facing the appearance inspection camera 51.

The appearance inspection unit 52 is provided at a position downstream of the position facing the conveyance drum 10 along the conveyance direction of the conveyance belt 20 and at a position where the upstream side of the inkjet head 61 can be imaged. The appearance inspection unit 52 includes a plurality of imaging units 52A each for sequentially imaging one tablet. The arrangement and specific configuration of each imaging unit 52A will be described later.

The appearance inspection unit 53 is provided on the downstream side of the position facing the conveyance belt 20 along the conveyance direction of the conveyance belt 30 and at a position where the upstream side of the inkjet head 62 can be imaged. The appearance inspection unit 53 includes a plurality of imaging units 53A that sequentially image one tablet. The arrangement and specific configuration of the imaging unit 53A are the same as those of the imaging unit 52A in the appearance inspection unit 52.

In this embodiment, a tablet printing apparatus including two appearance inspection units is illustrated, but the arrangement and the number of appearance inspection units are limited to the case illustrated in this embodiment. is not. That is, it can be assumed that the appearance inspection unit is arranged at another location in the transport path. When one appearance inspection unit is provided, the appearance inspection unit is replaced with the appearance inspection unit. When three are provided, it is also possible to assume a case where three or more appearance inspection units are provided.

The inkjet head 61 and the inkjet head 62 are provided with a plurality of ejection nozzles, and eject ink droplets from these ejection nozzles by an inkjet method. The ink jet system may be a piezo system that discharges ink droplets by applying a voltage to a piezo element (piezoelectric element) and deforms it, or an ink liquid by energizing a heater to heat the ink. A thermal system that ejects droplets may be used.

In the present embodiment, in order to perform a printing process on a pharmaceutical tablet or the like, as the ink ejected from the inkjet head 61 and the inkjet head 62, an edible ink manufactured from a raw material approved by the Food Sanitation Law is used. It is desirable to do. The inkjet head 61 and the inkjet head 62 can eject four colors of ink of cyan (C), magenta (M), yellow (Y), and black (K), and color printing can be performed by mixing these inks. Is possible. However, the color of the ink ejected by the inkjet head 61 and the inkjet head 62 is not limited to this. Further, it is not necessary that the colors of the inks ejected by the heads are all different, and the colors of the inks ejected by some of the heads may be the same color.

The inkjet head 61 is provided on the downstream side of the appearance inspection unit 52 along the conveyance direction of the conveyance belt 20. The inkjet head 61 performs a printing process on a plurality of tablets that are sucked and held by the transport belt 20 and transported.

Further, the inkjet head 62 is provided on the downstream side of the appearance inspection unit 53 along the conveyance direction of the conveyance belt 30. The inkjet head 62 performs a printing process on a plurality of tablets that are sucked and held by the transport belt 30 and transported.

The inkjet head 61 and the inkjet head 62 are preferably full line heads that cover the entire width direction of the conveyor belt 20 and the conveyor belt 30, respectively.

Further, the tablet printing apparatus 1 includes a product inspection camera 71 and a product inspection camera 72. As the product inspection camera 71 and the product inspection camera 72, for example, a CCD camera can be used. The product inspection camera 71 is installed facing the outer peripheral surface so that the imaging area is the outer peripheral surface of the pulley 10A. The product inspection camera 71 is provided at a position where the downstream side of the inkjet head 61 can be imaged along the conveyance direction of the conveyance belt 20. The product inspection camera 71 images a plurality of tablets that are sucked and held by the transport belt 20 and transported.

The product inspection camera 72 is installed facing the outer peripheral surface so that the imaging area is the outer peripheral surface of the pulley 10B. The product inspection camera 72 images a plurality of tablets that are sucked and held by the transport belt 30 and transported.

Further, the tablet printing apparatus 1 includes a heater 76 and a heater 77. As the heater 76 and the heater 77, for example, a hot-air drying heater that blows hot air to heat and dry the tablet can be used. The heater 76 is provided on the downstream side of the inkjet head 61 along the conveyance direction of the conveyance belt 20. The heater 76 blows hot air on the tablets that have been printed by the inkjet head 61 and dries them.

The heater 77 is provided on the downstream side of the inkjet head 62 along the conveyance direction of the conveyance belt 30. The heater 77 blows hot air on the tablet that has been printed by the inkjet head 62 and dries it.

Although the heater 76 and the heater 77 are provided below the conveyor belt 20 and the conveyor belt 30, respectively, the conveyor belt 20 and the conveyor belt 30 convey and hold tablets by adsorption, as described above. Even if the tablet faces downward, the tablet is transported without dropping.

Also, a heater is not necessarily used for the tablet drying process, and depending on the type of tablet, it may be desirable to dry it by natural drying. In that case, the heater 76 and the heater 77 may not be provided.

Furthermore, the tablet printing apparatus 1 includes a cleaning mechanism 83 and a cleaning mechanism 84. The powder generated from the tablet may adhere to the conveyor belt 20 and the conveyor belt 30. The cleaning mechanism 83 and the cleaning mechanism 84 clean the powder adhering to the transport belt 20 and the transport belt 30, respectively. As the cleaning mechanism 83 and the cleaning mechanism 84, for example, a mechanism that sucks and collects the ambient atmosphere by blowing air can be employed.

The control unit 3 controls the various operation mechanisms provided in the tablet printing apparatus 1. The configuration of the control unit 3 as hardware is the same as that of a general computer. That is, the control unit 3 stores a CPU that performs various arithmetic processes, a ROM that is a read-only memory that stores basic programs, a RAM that is a readable and writable memory that stores various information, control software, data, and the like. It is configured with a magnetic disk. When the CPU of the control unit 3 executes a predetermined processing program, processing for the tablet in the tablet printing apparatus 1 proceeds. The control unit 3 also has a function as a print control unit that controls the inkjet head 61 and the inkjet head 62 based on image data acquired by the appearance inspection camera 51, the appearance inspection unit 52, the appearance inspection unit 53, and the like. ing.

<About the configuration of the imaging unit>
FIG. 3 is a cross-sectional view illustrating a specific configuration of the imaging unit 52A. As illustrated in FIG. 3, the imaging unit 52A includes an imaging camera 102, an optical system 104, an upper illumination 106, and a plurality of side illuminations 108 arranged in a ring shape.

The imaging camera 102 is, for example, a CMOS camera. The imaging camera 102 includes a lens 102 </ b> A that receives light guided to the optical system 104. The imaging camera 102 is attached to the upper surface of the housing 101 of the imaging unit 52A in such a manner that the lens 102A is fitted into the hole 101A. The imaging camera 102 images the tablet 2 and further generates image data of the tablet 2.

The optical system 104 includes a reflection mirror 104A and a quadrangular pyramid mirror 104B. The optical system 104 condenses the light reflected by the target tablet 2 on the lens 102 </ b> A of the imaging camera 102 while bypassing the upper illumination 106.

The quadrangular pyramid mirror 104B is located in the lower part in the housing 101 and is disposed on the optical axis of the imaging camera 102. The reflection mirror 104A is located at the lower part in the housing 101 and is disposed so as to surround the quadrangular pyramid mirror 104B in a plan view (that is, viewed from the direction along the optical axis of the imaging camera 102). In the present embodiment, the quadrangular pyramid mirror 104B is exemplified, 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 light reflected by the tablet 2 enters the reflection mirror 104A, is further reflected by the reflection mirror 104A, and enters the quadrangular pyramid mirror 104B. Then, the light is further reflected by the quadrangular pyramid mirror 104B and guided to the lens 102A of the imaging camera 102.

The upper illumination 106 is attached to the lower surface of the housing 101 and is disposed on the optical axis of the imaging camera 102 or in the vicinity of the optical axis. That is, the upper illumination 106 is positioned substantially on the back side of the quadrangular pyramid mirror 104B with the housing 101 interposed therebetween. The upper illumination 106 mainly irradiates light on the main surface of the tablet 2 that faces the upper illumination 106. The “main surface facing the upper illumination 106” is the main surface opposite to the surface contacting the transport belt of the tablet 2 being transported, and the surface is the surface of the tablet 2. It doesn't matter whether it's on the back or the back. If the tablet 2 being conveyed is in a state in which the tablet 2 is directed vertically downward (a state in which the suction hole is opened downward), the surface facing the vertically downward side becomes the main surface facing the tablet 2.

The plurality of side lights 108 arranged in a ring shape are located below the housing 101 and are arranged so as to surround at least part of the periphery of the upper light 106 in a plan view. Each side illumination 108 mainly irradiates light to the side surface of the tablet 2 facing the side illumination 108. An angle α formed by the optical axis of the side illumination 108 and the vertical direction (Z-axis direction) is, for example, 50 °. The ring-shaped side illumination 108 may be formed integrally with the housing 101.

FIG. 4 is a diagram when the imaging unit 52A is looked up from the Z-axis negative direction. As illustrated in FIG. 4, the upper illumination 106 and the side illumination 108 are arranged so as to avoid the light path when the light reflected by the tablet 2 enters the reflection mirror 104A.

That is, an opening 101B for introducing light is formed on the lower surface of the housing 101, and the upper illumination 106 is attached to an attachment portion 101C for attaching to the lower surface of the housing 101 in the opening 101B. The light reflected by the tablet 2 is guided into the housing 101 from the opening 101B formed surrounding the upper illumination 106, and reaches the reflection mirror 104A. The reflection mirror 104 </ b> A surrounds the tablet 2 in a plan view and is positioned above the main surface facing the upward illumination 106 of the tablet 2.

Further, the ring-shaped side illumination 108 is arranged at a position overlapping the edge of the opening 101B in plan view, but the ring-shaped side illumination 108 is formed from the tablet 2 as illustrated in FIG. Since it is located below the path of light reaching the reflection mirror 104A, it does not hinder the collection of the light reflected by the tablet 2.

Each imaging unit 52 </ b> A is installed to face the conveyance surface so that the imaging area includes one tablet arranged on the conveyance surface of the conveyance belt 20. In the present embodiment, five rows of tablets are arranged and transported in the belt width direction (Y-axis direction), and therefore five imaging units 52A are also provided for each row of tablets 2.

FIG. 5 is a plan view illustrating the arrangement of the imaging unit 52A in the appearance inspection unit 52. As shown in FIG. In FIG. 5, the tablet 2 captured by each imaging unit 52 </ b> A is indicated by a dotted line because it is arranged, for example, at the center position of the imaging unit 52 </ b> A.

Corresponding to a plurality of tablets arranged, a plurality of imaging units 52A are arranged in the belt width direction (Y-axis direction). However, when the interval in the width direction (Y-axis direction) of the plurality of arranged tablet belts is narrower than the housing width of the imaging unit 52A, the imaging unit 52A is transported as illustrated in FIG. You may divide and arrange | position in the some line in a direction (X-axis direction).

Here, in order to make it easy to arrange the imaging units 52A densely, it is desirable that the arrangement width of the ring-shaped side illumination 108 be within the arrangement width of the optical system 104, particularly the arrangement width of the reflection mirror 104A.

<About operation of tablet printer>
Next, the processing operation in the tablet printing apparatus 1 having the above configuration will be described. 6 and 7 are flowcharts showing the procedure of the processing operation in the tablet printing apparatus 1.

First, a plurality of tablets are collectively put into the hopper 8 of the tablet printing apparatus 1 (step S1). The batch loading of tablets may be performed manually by an operator using a bucket or the like, or may be automatically performed by a transport mechanism separate from the tablet printing apparatus 1.

In this embodiment, a plurality of disc-shaped tablets 2 are put into the hopper 8. FIG. 8 is a plan view of the tablet 2. A split line 7 is formed on one side of the tablet 2 to divide it in half. The secant 7 is a groove carved along the radial direction of the disc-shaped tablet 2. The secant 7 is formed only on one side of the tablet 2.

In this embodiment, the surface on the side where the secant 7 is provided is the surface of the tablet 2. The secant 7 is not formed on the back surface of the tablet 2. In addition, there is no difference in the properties as a medicine between the front surface and the back surface of the tablet 2, and the surface on the side where the secant line 7 is provided is merely used as the front surface for convenience of distinction.

The plurality of tablets 2 put into the hopper 8 are guided to the transport drum 10, and the plurality of tablets 2 are sucked and held in the suction holes 11 of the transport drum 10 one by one.

The conveyance drum 10 has suction holes 11 formed in five rows along a direction perpendicular to the conveyance direction (the circumferential direction of the conveyance drum 10), that is, along the central axis direction of the conveyance drum 10. Accordingly, the transport drum 10 transports the plurality of tablets 2 in five rows in which five tablets are aligned in a direction perpendicular to the transport direction.

In this specification, a unit in which five tablets are arranged in a direction perpendicular to the conveyance direction of the conveyance drum 10 is denoted as “row”. That is, the transport drum 10 sucks and holds the tablets 2 individually in the suction holes 11 and transports the plurality of tablets 2 in a state in which the tablets 2 are arranged in a plurality of rows and columns (step S2).

In addition, an alignment mechanism for aligning and supplying a plurality of tablets 2 to the hopper 8 may be attached so that the transport drum 10 can smoothly suck and hold the tablets 2 loaded from the hopper 8 by five. Good. As such an alignment mechanism, for example, a ball feeder type mechanism can be employed.

Next, the appearance inspection camera 51 images the plurality of tablets 2 being transported by the transport drum 10 (step S3). The plurality of tablets 2 are held in the suction holes 11 of the transport drum 10 and are transported clockwise along the circumferential direction of the transport drum 10 on the paper surface of FIG. Although the plurality of tablets 2 are conveyed in an array of 5 rows, it is completely random whether the surface of each tablet 2 faces the inside of the conveyance drum 10 (the center side of the conveyance drum 10) or the outside. . Further, since the circular tablet 2 is held by the circular suction hole 11, the directionality of the tablet 2 is arbitrary, and the direction of the dividing line 7 of each tablet 2 conveyed by the conveyance drum 10 is completely random.

The appearance inspection camera 51 images the tablet 2 from the outside of the transport drum 10. Therefore, the plurality of tablets 2 imaged by the appearance inspection camera 51 randomly include those having the front surface facing the appearance inspection camera 51 and those facing the back surface.

Further, the foreign substance adhering to the plurality of tablets 2 is detected by the appearance inspection camera 51 (step S4). Usually, when the tablet 2 which is a pharmaceutical product is manufactured, thorough quality control is performed so that foreign matters are not mixed, but foreign materials may still be mixed. Examples of such a foreign material include human hair and metal powder.

Image data that is a result of imaging by the appearance inspection camera 51 is transferred to the control unit 3. The control unit 3 performs predetermined image processing on the image data, thereby recognizing the direction of the dividing line 7 of the tablet 2 and the tablet 2 to which foreign matter is attached.

Next, tablets 2 in 5 columns and 1 row are further transported by the transport drum 10 and reach a position facing the transport belt 20 in close proximity. At this time, the blowing mechanism of the transport drum 10 blows air to the five suction holes 11 in which the tablets 2 in the five rows and one row are sucked and held, thereby changing the suction state to the tablets 2 in the five rows and one row. To release.

On the other hand, a negative pressure is acting on the suction hole 21 of the holding plate 22 of the conveyor belt 20 at a position close to and opposed to the conveyor drum 10. Accordingly, the tablets 2 in the 5 columns and 1 row released from the suction state by the transport drum 10 are transferred from the suction holes 11 of the transport drum 10 to the suction holes 21 of the transport belt 20 and sucked and held.

In order to reliably deliver such a tablet 2, the control unit 3 equalizes the conveyance speed of the conveyance drum 10 and the conveyance speed of the conveyance belt 20, and the suction hole 11 and the suction hole 21 accurately face each other. In this way, control is performed to synchronize the operations of both transport units.

When the tablets 2 are transferred from the transport drum 10 to the transport belt 20, the respective tablets 2 are reversed. That is, the tablet 2 that has been sucked and held with the front surface on which the dividing line 7 is formed on the transport drum 10 facing outward is sucked and held in the suction hole 21 of the transport belt 20 with the back surface facing outward. On the contrary, the tablet 2 that has been sucked and held on the transport drum 10 with the back surface facing outward is sucked and held on the transport belt 20 with the front surface facing outward.

Therefore, each tablet 2 transported by the transport drum 10 is turned upside down while maintaining its direction, delivered to the transport belt 20 and transported.

Subsequently, the appearance inspection unit 52 images the plurality of tablets 2 being transported by the transport belt 20 (step S5). The conveyance belt 20 conveys the plurality of tablets 2 received by being reversed from the conveyance drum 10 by aligning them in five rows in a direction perpendicular to the conveyance direction. The appearance inspection unit 52 images the tablet 2 from the outside of the conveyor belt 20. Therefore, the plurality of tablets 2 imaged by the appearance inspection unit 52 randomly include those having the front surface facing the appearance inspection unit 52 and those facing the back surface.

However, since each tablet 2 is reversed when the tablets 2 are delivered from the transport drum 10 to the transport belt 20, the front and back of each tablet 2 imaged by the appearance inspection camera 51 and the corresponding tablet 2 imaged by the appearance inspection unit 52 are displayed. Is completely the opposite.

FIG. 9 is a diagram illustrating an example of an imaging result obtained by the imaging unit 52A. As illustrated in FIG. 9, the image of the tablet 2 obtained in the imaging unit 52 </ b> A is an image obtained by capturing the main surface facing the upper illumination 106 of the tablet 2 from obliquely above. This is because, as illustrated in FIG. 3, the light guided to the lens 102 </ b> A of the imaging camera 102 by the optical system 104 is light that has reached the reflection mirror 104 </ b> A located obliquely above the tablet 2. In the present embodiment, images captured from four directions obliquely above one tablet 2 are created by the light guided from the reflecting mirror 104A to the lens 102A via the quadrangular pyramid mirror 104B.

The imaging unit 52A captures an image of the tablet 2 as illustrated in FIG. 9, whereby the main surface and the side surface of the tablet 2 facing the upward illumination 106 can be simultaneously inspected. Here, the main surface facing the upper illumination 106 of the tablet 2 imaged in the imaging unit 52A is referred to as a “first surface” for convenience.

The appearance inspection of the first surface and the side surface of one tablet 2 is performed using the image (step S6). Specifically, the first surface and the side surface are inspected for foreign matter, scratches or defects.

9 is transmitted to the control unit 3. The controller 3 recognizes foreign matter, scratches, defects, or the like on the first surface and the side surface of one tablet 2 by performing predetermined image processing on the image data.

Specifically, the image data is divided into several regions (for example, two regions divided by the dividing line on the surface of the tablet, the side of the tablet, or the periphery of the dividing line), and the difference in gradation (gradation) in each region. A threshold is set for (difference). Then, a portion where the difference in gradation from the surrounding area is equal to or greater than the threshold is detected as a defect.

Alternatively, the following method may be used. That is, the contour of the tablet 2 is extracted using the difference in gradation (gradation difference) in the image data. The contour is extracted by, for example, calculating a point sequence based on the gradation difference and approximating the point sequence to an ellipse. Then, a scratch, a defect, a black spot, or the like in the tablet 2 is detected with reference to a predetermined gradation threshold value on each of the first surface and the side surface.

In addition, the said black spot is a location where a gradation degree is lower than the surrounding area | region, for example, respond | corresponds to the stain | pollution | contamination in a tablet 2, a foreign material, or a burn. At this time, the control unit 3 also recognizes the direction of the secant 7 of the tablet 2 based on the image data.

Here, the imaging unit 52A in the present embodiment can realize a plurality of irradiation patterns on the tablet 2 by adjusting the amount of light irradiated by the upper illumination 106 and the plurality of side illuminations 108. Note that the irradiation pattern may be switched by a changeover switch and an adjustment switch provided in the imaging unit 52A, or by an external control device (for example, the control unit 3).

In the present embodiment, it is assumed that the tablet 2 is transported at a transport speed of 250 mm / s, for example, and the exposure time for imaging the tablet 2 is limited to about 50 μs. In such a case, the imaging unit 52A images the tablet 2 with the following two irradiation patterns.

<First irradiation pattern>
In the first irradiation pattern, the upper illumination 106 in the imaging unit 52A sets the amount of light that the tablet 2 is irradiated relatively high, and the ring-shaped side illumination 108 irradiates the tablet 2 with the amount of light emitted by the upper illumination 106. It is the irradiation pattern set lower than.

FIG. 10 is a diagram illustrating an example of image data captured with the first irradiation pattern. As illustrated in FIG. 10, in the tablet 2 in the image data, a defect is detected in the contour of the inclined portion close to the first surface among the side surfaces.

By imaging with the first irradiation pattern, the amount of light irradiated radially from the top of the tablet 2 (that is, the optical axis of the imaging camera 102) is larger than the amount of light irradiated from the periphery of the tablet 2 toward the tablet 2. Therefore, the difference between the gradation on the first surface and the gradation on the side surface of the tablet 2 can be increased. In the case illustrated in FIG. 10, the difference between the average gradation on the first surface of the tablet 2 and the average gradation on the side of the tablet 2 is 20 gradations with 8 bits (256 gradations). Degree. Therefore, the extraction accuracy of the outline of the tablet 2 is also increased.

In FIG. 10, since the contour of the inclined portion close to the first surface of the side surfaces of the tablet 2 is also extracted with high accuracy, the defect 6 is detected. Further, since the gradation of the first surface is relatively high, the internal shape of the secant 7 can be recognized with high accuracy. Therefore, it is possible to detect a case where there is a scratch, a defect, a black spot, or the like in the secant line 7.

On the other hand, in FIG. 11, for the same tablet 2, the amount of light that the upper illumination 106 irradiates the tablet 2 is set to be equal to the amount of light that the ring-shaped side illumination 108 irradiates the tablet 2. It is a figure which shows an example of the image data imaged in the state.

In FIG. 11, there is no difference between the amount of light that the upper illumination 106 irradiates the tablet 2 and the amount of light that the ring-shaped side illumination 108 irradiates the tablet 2, and the tablet 2 is irradiated with light uniformly. Of the side surfaces, the contour of the inclined portion close to the first surface cannot be recognized on the image data. For this reason, it is not possible to detect a defect at the location.

Here, the uniform irradiation of light onto the tablet 2 means that the direction inclined from the direction along the optical axis of the imaging camera 102 that images the tablet 2 to the first direction is the first irradiation direction (the imaging camera 102 in plan view). (Radiation direction extending radially from) and the direction inclined to the opposite side is the second irradiation direction (irradiation direction from the periphery of the imaging camera 102 toward the optical axis in plan view), along the first irradiation direction. Thus, the amount of light applied to the tablet 2 is equal to the amount of light applied to the tablet 2 along the second irradiation direction.

In the case illustrated in FIG. 11, referring also to FIG. 3, the omnidirectional light is irradiated onto the tablet 2 by the upper illumination 106 and the ring-shaped side illumination 108. Therefore, it is considered that the amount of light along the first irradiation direction is equal to the amount of light along the second irradiation direction.

On the other hand, in the case illustrated in FIG. 10, referring also to FIG. 3, the first irradiation is performed in the direction extending radially from the imaging camera 102 in plan view (that is, the direction separating from the optical axis as approaching the tablet 2). As a direction, the direction from the periphery of the imaging camera 102 toward the optical axis in plan view (that is, the direction approaching the optical axis as approaching the tablet 2) is the second irradiation direction, and the amount of light along the first irradiation direction is It is considered that the amount of light is larger than the second irradiation direction. As described above, there is a difference between the light amount along the first irradiation direction and the light amount along the second irradiation direction, thereby increasing the difference in gradation and improving the extraction accuracy of the contour of the tablet 2. it can.

In addition, in FIG. 10, although the case where a difference arises in the whole surface of the tablet 2 between the light quantity along a 1st irradiation direction and the light quantity along a 2nd irradiation direction was illustrated, it follows a 1st irradiation direction. The part where the difference occurs between the light amount and the light amount along the second irradiation direction may be a part of the tablet 2. Further, it is only necessary to define at least one direction of the first irradiation direction and the second irradiation direction that cause a difference with respect to the target portion.

In addition, since the accuracy of extracting the outline of the tablet 2 increases as the difference in gradation between the first surface and the side surface of the tablet 2 increases, it may be possible to turn off the ring-shaped side illumination 108. That is, it is possible to realize a state in which the amount of light along the first irradiation direction is larger than the amount of light along the second irradiation direction only by the upper illumination 106. On the other hand, if the amount of light of the entire image data is not sufficient, it becomes difficult to acquire image data having a sufficient amount of light for image processing. In such a case, the amount of light with which the ring-shaped side illumination 108 irradiates the side surface of the tablet 2 also needs to be greater than a certain level.

<Second irradiation pattern>
The second irradiation pattern is an irradiation pattern suitable for detecting a relatively shallow defect formed on the tablet 2, and turns off the upper illumination 106 in the imaging unit 52A and surrounds the upper illumination 106 in a plan view. This is an irradiation pattern in which only half of the side illumination 108 is turned on.

Here, the detection of a relatively shallow defect formed in the tablet 2 will be examined. FIG. 12 and FIG. 13 are conceptual diagrams illustrating light irradiated on a relatively shallow defect formed on the first surface of the tablet 2. 12 and 13, the direction of the optical axis of the imaging camera 102 in the imaging unit 52A is a direction along the Z-axis direction.

In FIG. 12, the light 200 that irradiates the tablet 2 by being inclined in the first direction from the direction along the optical axis of the imaging camera 102, and the second direction from the direction along the optical axis of the imaging camera 102 is inclined. The light 201 that irradiates the tablet 2 is irradiated to the same extent. That is, the light is uniformly irradiated to the tablet 2 in the direction.

In such a state, the relatively shallow defect 300 is uniformly irradiated with light on the bottom surface and side surfaces thereof, so that a difference in gradation is less likely to appear in the image data compared to a region where no defect is formed. Therefore, in such a light irradiation state, it is difficult to detect the relatively shallow defect 300 by image processing.

On the other hand, in FIG. 13, the light 200 is not irradiated, but only the light 201 is irradiated. In such a state, since light is not irradiated on one side surface of the relatively shallow defect 300, a shadow 202 portion that is not irradiated with light is formed. Therefore, a difference in gradation occurs in the image data as compared with a region where no defect is formed, and the relatively shallow defect 300 can be easily detected by image processing.

FIG. 14 is a diagram showing another example of image data captured with the second irradiation pattern. As illustrated in FIG. 14, the tablet 2 in the image data has a relatively shallow defect 300 detected on the first surface.

By imaging with the second irradiation pattern, as shown in FIG. 13 above, by forming a portion of the shadow 202 where the light is not irradiated on the defect 300, the relatively shallow defect 300 can be easily detected. Can do.

In addition, the irradiation pattern of the ring-shaped side illumination 108 for forming the shadow 202 portion on the defect 300 (that is, the illumination pattern for lighting a part of the plurality of side illuminations 108) is turned on for the above half circumference. It is not restricted to the irradiation pattern to be made.

On the other hand, FIG. 15 turns off the upper illumination 106 in the imaging unit 52A for the same tablet 2 and lights up the entire circumference of the ring-shaped side illumination 108 surrounding the upper illumination 106 in plan view. It is a figure which shows an example of the image data imaged in the made state.

In FIG. 15, since the tablet 2 is uniformly irradiated with light by the side illumination 108 for the entire circumference, no shadow portion is formed in a relatively shallow defect. Therefore, compared to a region where no defect is formed, a difference in gradation is less likely to appear in image data, and a relatively shallow defect cannot be detected by image processing.

In the case illustrated in FIG. 15, referring also to FIG. 3, the side illuminations 108 facing each other out of the side illuminations 108 for the entire circumference are irradiated with each other along the first irradiation direction and the second irradiation direction. Therefore, the amount of light along the first irradiation direction and the amount of light along the second irradiation direction are considered to be equal.

On the other hand, in the case illustrated in FIG. 14, if referring also to FIG. 3, the opposing side lights 108 of the side lights 108 for the entire circumference are paired with a lighting state and a light-off state. It is considered that there is a difference between the amount of light along the first irradiation direction and the amount of light along the second irradiation direction. Therefore, the relatively shallow defect 300 can be easily detected by forming a portion of the shadow 202 where the defect 300 is not irradiated with light.

According to the first irradiation pattern, the first surface and the side surface can be inspected at the same time for scratches, defects or black spots on the tablet 2, and the contour of the tablet 2 is extracted with high accuracy by the difference in gradation. can do. Further, scratches, defects or black spots in the dividing line 7 can be inspected.

In addition, according to the second irradiation pattern, it is possible to detect a relatively shallow defect that is difficult to detect only by the first irradiation pattern, based on the difference in gradation.

Therefore, by using the above-described two irradiation patterns, the appearance inspection of the tablet 2 can be performed with high accuracy and efficiency even under a situation where the exposure time is limited.

Next, the tablet 2 imaged by the appearance inspection unit 52 is further transported by the transport belt 20 and reaches a position facing the ink jet head 61. Then, the inkjet head 61 performs a printing process on the tablet 2 (step S7). Here, the control unit 3 controls the printing process by the inkjet head 61 based on the image data acquired by the appearance inspection camera 51 and the appearance inspection unit 52. FIG. 16 is a diagram illustrating an example of a print processing result by the inkjet head 61.

The inkjet head 61 performs a printing process on the first surfaces of the plurality of tablets 2 conveyed by the conveyance belt 20. However, the inkjet head 61 performs a printing process only on the tablet 2 in which no foreign matter or the like is detected in the appearance inspection process (step S4) and the appearance inspection process (step S6) among the plurality of tablets 2. Specifically, based on the image data acquired by the appearance inspection camera 51 and the appearance inspection unit 52, the tablet 2 in which no foreign matter or the like is detected by the appearance inspection camera 51 and the appearance inspection unit 52 among the plurality of tablets 2. The control unit 3 controls the ink jet head 61 so that the printing process is performed only for the ink jet head. That is, the inkjet head 61 does not perform the printing process on the tablet 2 in which foreign matter or the like is detected by the appearance inspection camera 51 and the appearance inspection unit 52.

Further, the control unit 3 performs the surface printing process on the ink jet head 61 based on the surface printing data for the tablet 2 whose first surface is the surface among the plurality of tablets 2 conveyed by the conveying belt 20. Let it be done. Here, for example, character data of “ABCD” is used as the front surface print data.

Further, the control unit 3 causes the inkjet head 61 to perform a surface printing process on the surface of the tablet 2 along a predetermined direction with respect to the secant 7 formed on the surface of the tablet 2. In the present embodiment, the inkjet head 61 performs a printing process along a direction parallel to the secant 7 on the surface of the tablet 2. Regarding the direction of the dividing line 7 in the tablet 2 whose first surface is the front surface among the plurality of tablets 2 conveyed by the conveying belt 20, image processing is performed on the image data acquired by the appearance inspection camera 51 and the appearance inspection unit 52. By applying, the control unit 3 can recognize.

Next, the tablet 2 on which the printing process for the first surface has been performed is further transported by the transport belt 20 and reaches a position facing the product inspection camera 71. The product inspection camera 71 images the first surfaces of the plurality of tablets 2 conveyed by the conveyance belt 20, and images the result of the printing process performed on the first surfaces of the plurality of tablets 2 by the inkjet head 61.

The product inspection camera 71 transmits the acquired image data to the control unit 3. Based on the image data acquired by the product inspection camera 71, the control unit 3 confirms the print processing result of the inkjet head 61 for the first surfaces of the plurality of tablets 2 (step S8).

Next, the tablet 2 in which the print processing result of the first surface has been inspected is further transported by the transport belt 20 and reaches a position facing the heater 76. As illustrated in FIG. 1, the heater 76 is installed below the conveyor belt 20, and when the tablet 2 reaches a position facing the heater 76, the tablet 2 is held downward by the conveyor belt 20. Will be. Since the transport belt 20 sucks and holds the tablet 2 by applying a negative pressure to the suction hole 21, it is also possible to hold the tablet 2 downward.

The heater 76 blows hot air on the first surface of the plurality of tablets 2 conveyed by the conveyance belt 20 to dry the plurality of tablets 2 (step S9). By performing such a drying process, the ink ejected from the inkjet head 61 to the plurality of tablets 2 can be quickly dried to prevent bleeding.

Next, the tablets 2 in 5 columns and 1 row dried by the heater 76 are further transported by the transport belt 20 and reach a position in close proximity to the transport belt 30. At this time, the blow mechanism of the conveyor belt 20 blows air to the five suction holes 21 in which the tablets 2 in the five rows and one row are held by suction, thereby releasing the suction state for the tablets 2 in the five rows and one row. To do. On the other hand, a negative pressure is applied to the suction hole of the conveyor belt 30 at a position facing the conveyor belt 20 in the vicinity. Accordingly, the tablets 2 in 5 columns and 1 row released from the suction state by the transport belt 20 are transferred from the suction holes 21 of the transport belt 20 to the suction holes of the transport belt 30 and sucked and held. In order to reliably deliver such a tablet 2, the control unit 3 equalizes the conveyance speed of the conveyance belt 20 and the conveyance speed of the conveyance belt 30 and makes the suction holes of both conveyance belts accurately face each other. The control of synchronizing the operations of both conveying belts is performed.

When the tablet 2 is delivered from the conveyor belt 20 to the conveyor belt 30, the tablet 2 moves as it is without rotating. That is, each tablet 2 is transferred from the conveyor belt 20 to the conveyor belt 30 while maintaining the direction of the dividing line 7.

In addition, when the tablets 2 are transferred from the transport belt 20 to the transport belt 30, each tablet 2 is reversed. In other words, the tablet 2 that has been sucked and held with the front surface on which the dividing line 7 is formed on the transport belt 20 facing the outside is sucked and held on the transport belt 30 with the back surface facing the outside. On the other hand, the tablet 2 that has been sucked and held on the transport belt 20 with the back surface facing outward is sucked and held on the transport belt 30 with the front surface facing outward. Therefore, each tablet 2 transported by the transport belt 20 is turned upside down while being maintained in its direction, transferred to the transport belt 30 and transported (step S10).

Subsequently, the appearance inspection unit 53 images the plurality of tablets 2 being transported by the transport belt 30 (step S11). The conveyance belt 30 conveys the plurality of tablets 2 received by being reversed from the conveyance belt 20 in five rows in a direction perpendicular to the conveyance direction. The appearance inspection unit 53 images the tablet 2 from the outside of the conveyance belt 30. Therefore, the front and back of each tablet 2 imaged by the appearance inspection unit 53 is completely opposite to the front and back of the corresponding tablet 2 imaged by the appearance inspection unit 52.

The imaging unit 53A having the same structure as the imaging unit 52A captures the image of the tablet 2 as illustrated in FIG. 9, thereby simultaneously performing the appearance inspection of the main surface and the side facing the upward illumination 106 of the tablet 2. It can be carried out. Here, the main surface facing the upper illumination 106 of the tablet 2 imaged by the imaging unit 53A is referred to as a “second surface” for convenience.

Using the image acquired by the imaging unit 53A, the appearance inspection of the second surface and the side surface of one tablet 2 is performed (step S12). Specifically, the second surface and the side surface are imaged using the first irradiation pattern and the second irradiation pattern to determine whether there are foreign objects, scratches or defects, and the acquired image data Inspect based.

Next, the tablet 2 imaged by the appearance inspection unit 53 is further transported by the transport belt 30 and reaches a position facing the inkjet head 62. Then, the inkjet head 62 performs a printing process on the tablet 2 (step S13). Here, the control unit 3 controls the printing process by the inkjet head 62 based on the image data acquired by the appearance inspection unit 53.

The inkjet head 62 performs a printing process on the second surfaces of the plurality of tablets 2 conveyed by the conveyance belt 30. However, as with the inkjet head 61, the inkjet head 62 detects foreign matter in both the appearance inspection process (step S4), the appearance inspection process (step S6), and the appearance inspection process (step S12) among the plurality of tablets 2. Only the tablet 2 that has not been printed is printed.

Specifically, based on the image data acquired by the appearance inspection camera 51, the appearance inspection unit 52, and the appearance inspection unit 53, the appearance inspection camera 51, the appearance inspection unit 52, and the appearance inspection unit 53 out of the plurality of tablets 2. The control unit 3 controls the inkjet head 62 so that the printing process is performed only on the tablet 2 in which no foreign matter or the like has been detected.

That is, the inkjet head 62 does not perform the printing process on the tablet 2 in which foreign matter or the like is detected by the appearance inspection camera 51, the appearance inspection unit 52, or the appearance inspection unit 53.

Further, the control unit 3 applies the front surface printing process to the inkjet head 62 based on the front surface print data for the tablet 2 whose second surface is the front surface among the plurality of tablets 2 transported by the transport belt 30. To do. Here, the front-side print data is “ABCD” character data similar to the above.

Furthermore, the control unit 3 causes the inkjet head 62 to perform a surface printing process on the surface along the predetermined direction with respect to the secant 7 formed on the surface of the tablet 2. In the present embodiment, the inkjet head 62 performs a printing process along a direction parallel to the secant 7 on the surface of the tablet 2. With respect to the direction of the secant 7 in the tablet 2 whose second surface is the front surface of the plurality of tablets 2 conveyed by the conveyance belt 30, the control unit performs image processing on the image data acquired by the appearance inspection unit 53. 3 can be recognized.

On the other hand, the control unit 3 also applies the back surface printing process to the inkjet head 62 based on the back surface print data for the tablet 2 whose second surface is the back surface among the plurality of tablets 2 transported by the transport belt 30. Can be performed.

The control unit 3 causes the inkjet head 62 to perform the printing process for the back surface of the tablet 2 along the same direction as the predetermined direction with respect to the secant 7 formed on the surface of the tablet 2. In the present embodiment, the printing process is performed on the surface of the tablet 2 along a direction parallel to the secant line 7, and also on the back surface of the tablet 2 along the direction parallel to the secant line 7 on the front surface side. Then, the inkjet head 62 performs a printing process. Regarding the direction of the front dividing line 7 in the tablet 2 whose second surface is the back surface among the plurality of tablets 2 transported by the transport belt 30, the image data acquired by the appearance inspection camera and the appearance inspection unit 52 is imaged. The control part 3 can recognize by performing a process.

Next, the tablet 2 on which the printing process for the second surface has been performed is further transported by the transport belt 30 and reaches a position facing the product inspection camera 72. The product inspection camera 72 images the second surfaces of the plurality of tablets 2 conveyed by the conveying belt 30 and images the result of the printing process performed on the second surfaces of the plurality of tablets 2 by the inkjet head 62.

The product inspection camera 72 transmits the acquired image data to the control unit 3. Based on the image data acquired by the product inspection camera 72, the control unit 3 confirms the print processing result of the inkjet head 62 for the second surfaces of the plurality of tablets 2 (step S14).

Subsequently, the tablet 2 whose print processing result has been inspected on the second surface is further conveyed by the conveyance belt 30 and reaches a position facing the heater 77. The heater 77 blows hot air on the second surfaces of the plurality of tablets 2 conveyed by the conveyance belt 30 to dry the plurality of tablets 2 (step S15). By performing such a drying process, the ink ejected from the inkjet head 62 to the plurality of tablets 2 can be quickly dried to prevent bleeding.

Finally, the sorting process is performed on the tablets 2 that have been inspected on both sides (step S16). The tablet 2 having no problem in the printing process on both the front and back sides in step S8 and step S14, that is, the non-defective tablet 2, is put into the non-defective product duct 48 by air blowing from the blow mechanism. The tablet 2 discharged into the non-defective duct 48 is collected in the non-defective product collection box 58.

On the other hand, the tablet 2 having a problem in the result of the printing process on either of the front and back sides, that is, the defective tablet 2 is put into the defective print duct 46 by air blowing from the blow mechanism. The tablet 2 discharged to the defective print duct 46 is collected in the defective print box 56.

Further, among the plurality of tablets 2, the tablets 2 in which the abnormality is detected by the appearance inspection camera 51, the appearance inspection unit 52, or the appearance inspection unit 53 are put into the appearance defective product duct 47 by air blowing from the blow mechanism. The tablet 2 discharged to the defective appearance duct 47 is collected in the defective appearance box 57. As described above, the tablet 2 in which a defect or the like is detected can be collected in the defective appearance product box 57 separately from the tablet 2 in which the printing process is performed without detecting the defect or the like.

As described above, the printing process on the tablet 2 in the tablet printing apparatus 1 is completed.

<About the effects produced by the embodiment described above>
Next, effects produced by the embodiment described above will be exemplified. In the following description, the effect is described based on the specific configuration exemplified in the above-described embodiment, but is exemplified in the present specification within a range in which the same effect occurs. Other specific configurations may be substituted.

According to the embodiment described above, the inspection apparatus includes at least one illumination, an imaging unit, and an inspection unit. Here, the illumination corresponds to, for example, at least one of the upper illumination 106 and the ring-shaped side illumination 108. The imaging unit corresponds to the imaging camera 102, for example. The inspection unit corresponds to the control unit 3, for example. The illumination can irradiate the object with light. Here, the object corresponds to the tablet 2, for example. The imaging camera 102 images the tablet 2 irradiated with light by illumination, and generates image data of the tablet 2. The control unit 3 performs an appearance inspection of the tablet 2 based on the image data of the tablet 2. Here, a direction inclined in the first direction from the direction along the optical axis of the imaging camera 102 that images the tablet 2 is defined as a first irradiation direction. Further, a direction inclined from the direction along the optical axis of the imaging camera 102 to the second direction opposite to the first direction is set as a second irradiation direction. And the light quantity which illumination irradiates to tablet 2 along a 1st irradiation direction is larger than the light quantity which illumination irradiates tablet 2 along a 2nd irradiation direction.

According to such a configuration, the amount of light irradiated along the first irradiation direction is made larger than the amount of light irradiated along the second irradiation direction to increase the difference in gradation in the image data. The accuracy of image recognition can be increased, and the accuracy of appearance inspection of the tablet 2 by imaging can be increased.

In the present embodiment, the configuration in which both the upper illumination 106 and the plurality of side illuminations 108 are provided is illustrated, but only one of the upper illumination 106 and the ring-shaped side illumination 108 is illustrated. May be provided. Further, in the present embodiment, the plurality of side lights 108 are disposed so as to surround the entire periphery of the upper illumination 106 in a plan view, but may be configured to surround at least a part of the entire periphery.

Further, according to the embodiment described above, the illumination includes a plurality of side illuminations 108 that are disposed so as to surround at least a part of the tablet 2 when viewed from the direction along the optical axis of the imaging camera 102. . According to such a configuration, the plurality of side lights 108 can irradiate light from only one direction around the tablet 2, and a shadow is formed on the image of the tablet 2 to form a relatively shallow defect. Even if it exists, it can detect easily.

Further, according to the embodiment described above, the plurality of side lights 108 are arranged so as to surround the tablet 2 when viewed from the direction along the optical axis of the imaging camera 102. When viewed from the direction along the optical axis of the imaging camera 102, only one of the pair of side lights 108 that sandwich the tablet 2 irradiates the tablet 2 with light. According to such a configuration, the ring-shaped side illumination 108 is partially turned on to irradiate light only from one direction around the tablet 2 and form a shadow on the image of the tablet 2. Even a relatively shallow defect can be easily detected.

Also, according to the embodiment described above, the illumination includes at least one upper illumination 106 disposed on the optical axis of the imaging camera 102. The inspection apparatus includes an optical system 104 that guides light reflected by the tablet 2 irradiated with light from the upper illumination 106 to the imaging camera 102 while bypassing the upper illumination 106. According to such a configuration, the amount of light irradiated radially from the optical axis of the imaging camera 102 to the tablet 2 by the upper illumination 106 becomes higher than the amount of light irradiated from the periphery of the tablet 2 toward the tablet 2. . Therefore, the difference between the gradation on the main surface of the tablet 2 and the gradation on the side surface can be increased, and a relatively shallow defect can be easily detected by image processing.

Further, according to the embodiment described above, the illumination includes a plurality of side illuminations 108 arranged so as to surround at least a part of the tablet 2 when viewed from the direction along the optical axis of the imaging camera 102. The plurality of side lights 108 are arranged in a range where the optical system 104 is arranged when viewed from the direction along the optical axis of the imaging camera 102. According to such a configuration, since the width in the width direction (Y-axis direction) of the conveyance belt of the imaging unit can be up to the width of the optical system 104, the structure of the imaging unit can be reduced, and the imaging unit It becomes easy to arrange closely. If the image pickup units can be densely arranged in the width direction of the transport belt, it is not necessary to shift the image pickup unit in the transport direction of the transport belt (X-axis direction), or it is shifted in the transport direction of the transport belt. The range to do can be suppressed.

Further, according to the embodiment described above, the first irradiation direction is a direction extending radially from the imaging camera 102 in a plan view. The second irradiation direction is a direction from the periphery of the imaging camera 102 toward the optical axis in plan view. According to such a configuration, when the upper illumination 106 and the ring-shaped side illumination 108 are used in combination, the amount of light emitted radially from the upper illumination 106 is changed from the side illumination 108 around the tablet 2 to the tablet. Therefore, the difference between the gradation on the first surface and the gradation on the side surface of the tablet 2 can be increased.

In addition, according to the embodiment described above, the printing unit for printing on the tablet 2 inspected by the inspection apparatus is provided. Here, the printing unit corresponds to at least one of the inkjet head 61 and the inkjet head 62, for example. According to such a configuration, since printing is performed only on the tablet 2 that has been visually inspected with high accuracy, it is possible to prevent the tablet 2 having a foreign object, a scratch, a defect, or the like from being collected as a non-defective product. it can.

The tablet printing apparatus 1 includes a product inspection camera 71 and a product inspection camera 72, which inspects the tablet 2 after the printing process. However, if a printing process is performed on the tablet 2 to which foreign matter is adhered, if the ink is applied from above the foreign matter, the foreign matter cannot be detected and the foreign matter adhered tablet 2 is regarded as a good product collection box. There is also a risk of recovery to 58.

If the printing process is performed only on the tablet 2 in which no foreign matter or the like is detected among the plurality of tablets 2 as in the present embodiment, the printing process is not performed on the tablet 2 on which the foreign matter has adhered. Therefore, such a tablet 2 is prevented from passing through the inspection and being collected in the non-defective product collection box 58. As a result, it is possible to prevent the tablet 2 to which foreign matter is adhered.

<Modifications in Embodiments Described above>
Although the embodiments have been described above, the present invention can be modified in various ways other than those described above without departing from the gist thereof. For example, in the above embodiment, the printing process is performed on both the front and back surfaces of the tablet 2, but the printing process may be performed only on either the front surface or the back surface.

For example, if the printing process is performed only on the surface, the printing process is performed by the inkjet head 61 on the tablet 2 whose first surface conveyed by the conveyance belt 20 is the surface, and the tablet 2 is conveyed by the conveyance belt 30. A printing process is performed on the tablet 2 whose second surface is the surface by the inkjet head 62.

In the above-described embodiment, the appearance inspection accuracy is improved by performing the appearance inspection of the tablet 2 using the appearance inspection unit 52 and the appearance inspection unit 53 that increase the accuracy of image recognition. By applying the same structure as the appearance inspection unit 52, it is possible to perform the appearance inspection on both the front and back surfaces of the tablet 2 with high accuracy before the tablet 2 reaches the position facing the inkjet head 62. In that case, since the tablets 2 to be subjected to the printing process in the inkjet head 62 are limited to the tablets 2 having no problem in the appearance inspection on both the front and back surfaces, the production efficiency can be improved.

On the other hand, when the appearance inspection of the tablet 2 is performed using the appearance inspection unit 52 and the appearance inspection unit 53 at a position facing the transport belt 20 which is a plane as in the case of the above-described embodiment, Since focusing can be performed over a wider range than when imaging a cylindrical peripheral surface, the degree of freedom of the types and number of tablets that can be imaged increases. In addition, the accuracy of image recognition can be improved.

Also, when the secant 7 is not provided on the tablet 2, that is, when the printing process is performed on the tablet 2 with no distinction between the front and the back, the technology relating to the present embodiment can be applied. In this case, as long as printing is possible only on one side of the tablet 2, printing may be performed by only one of the inkjet head 61 and the inkjet head 62. Even in this case, the inkjet head 61 or the inkjet head 62 is only applied to the tablet 2 in which no foreign matter is detected by the appearance inspection camera 51, the appearance inspection unit 52, and the appearance inspection unit 53 among the plurality of tablets 2. Perform the printing process.

In addition, when printing is performed on the tablet 2 with no distinction between the front and back, if printing is performed with only one of the inkjet head 61 and the inkjet head 62, the appearance inspection camera 51, the appearance inspection unit 52, and the appearance are not necessarily required. It is not necessary to detect foreign matter or the like on both sides of the tablet 2 by the inspection unit 53. In this case, if foreign matter is detected only on the side of the tablet 2 on which the printing process is performed and only the tablet 2 on which no foreign matter is detected is detected, the foreign matter can be obtained. It is possible to prevent the printing process from being performed from above.

In addition, when the foreign substance has adhered to the surface of the tablet 2 on which the foreign substance is not detected, the foreign substance is detected by a separate inspection (for example, inspection by the product inspection camera 71 and the product inspection camera 72). Therefore, it is prevented that the tablet 2 is mixed into a non-defective product. That is, foreign matter or the like may be detected on at least the surface on which the printing process is performed, of the front and back surfaces of the tablet 2.

Further, in the above-described embodiment, the printing process is performed by an ink jet method that discharges ink droplets, but the printing process method is not limited to this, and intaglio printing including letterpress printing and gravure printing, Alternatively, laser printing or the like may be used.

Further, the shape of the tablet 2 is not limited to the disk shape, and may be another shape such as a substantially elliptical shape or a rod shape. In this case, the suction hole of each transport unit is in accordance with the shape of the tablet 2.

Moreover, in the said embodiment, although it was made to convey the tablet 2 by the unit of 5 columns 1 line, it is not limited to this, You may make it convey the tablet 2 by 1 row, You may make it convey the tablet 2 by two or more rows.

DESCRIPTION OF SYMBOLS 1 Tablet printer 2 Tablet 3 Control part 5,101 Case 6,300 Defect 7 Split line 8 Hopper 10 Conveyance drum 10A, 10B Pulley 11,21 Adsorption hole 20,30 Conveyor belt 22 Holding plate 46 Print defective product duct 47 Appearance defect Good product duct 48 Good product duct 51 Appearance inspection camera 52, 53 Appearance inspection unit 52A, 53A Imaging unit 56 Print defective product box 57 Appearance defective product box 58 Good product recovery box 61, 62 Inkjet head 71, 72 Product inspection camera 76, 77 Heater 83 , 84 Cleaning mechanism 101A Hole portion 101B Opening 101C Mounting portion 102 Imaging camera 102A Lens 104 Optical system 104A Reflection mirror 104B Square pyramid mirror 106 Upper illumination 108 Side illumination 122 Straight feeder 123 Rotating feeder 1 4 supply feeders 200, 201 light 202 Shadow

Claims (10)

1. At least one illumination capable of illuminating the object;
   An imaging unit that images the object irradiated with light by the illumination and generates image data of the object;
   An inspection unit that performs an appearance inspection of the object based on the image data of the object;
   The direction inclined from the direction along the optical axis of the imaging unit that images the object to the first direction is the first irradiation direction,
   The direction inclined from the direction along the optical axis of the imaging unit to the second direction opposite to the first direction is a second irradiation direction,
   The amount of light that the illumination irradiates the object along the first irradiation direction is greater than the amount of light that the illumination irradiates the object along the second irradiation direction.
   Inspection device.
2. The illumination includes a plurality of side illuminations that are disposed so as to surround at least a part of the object as viewed from a direction along the optical axis of the imaging unit.
   The inspection apparatus according to claim 1.
3. The plurality of side illuminations are arranged so as to surround the object as seen from the direction along the optical axis of the imaging unit,
   Only one of the pair of side illuminations sandwiching the target object irradiates the target object with light as viewed from the direction along the optical axis of the imaging unit.
   The inspection apparatus according to claim 2.
4. The illumination includes at least one upward illumination disposed on the optical axis of the imaging unit,
   An optical system for guiding light reflected by the object irradiated with light from the upper illumination to the imaging unit while bypassing the upper illumination;
   The inspection apparatus according to any one of claims 1 to 3.
5. The illumination includes a plurality of side illuminations arranged to surround at least a part of the object when viewed from a direction along the optical axis of the imaging unit,
   The plurality of side illuminations are disposed within a range in which the optical system is disposed when viewed from a direction along the optical axis of the imaging unit.
   The inspection apparatus according to claim 4.
6. The first irradiation direction is a direction extending radially from the imaging unit in a plan view,
   The second irradiation direction is a direction from the periphery of the imaging unit toward the optical axis in plan view.
   The inspection apparatus according to any one of claims 1 to 5.
7. The lighting is
   A plurality of side illuminations arranged to surround at least a part of the object as seen from the direction along the optical axis of the imaging unit;
   And at least one upward illumination disposed on the optical axis of the imaging unit,
   An optical system for guiding the light reflected by the object irradiated with light from the upper illumination to the imaging unit while bypassing the upper illumination;
   The imaging unit images the object irradiated with light by a plurality of irradiation patterns using the plurality of side illuminations and the upper illumination, and generates image data of the object.
   The inspection apparatus according to any one of claims 1 to 6.
8. The inspection apparatus according to any one of claims 1 to 7,
   A printing unit that performs printing on the tablet inspected by the inspection device,
   Tablet printing device.
9. Imaging an object illuminated with light by at least one illumination and generating image data of the object;
   A step of performing an appearance inspection of the object based on the image data of the object;
   The direction inclined from the direction along the optical axis of the imaging unit that images the object to the first direction is the first irradiation direction,
   The direction inclined from the direction along the optical axis of the imaging unit to the second direction opposite to the first direction is a second irradiation direction,
   The amount of light that the illumination irradiates the object along the first irradiation direction is greater than the amount of light that the illumination irradiates the object along the second irradiation direction.
   Inspection method.
10. Comprising a step of printing on the tablet inspected by the inspection method according to claim 9;
    Tablet printing method.

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