JP2021065301A - Visual inspection device, visual inspection method, and tablet printing device - Google Patents

Abstract

To provide a visual inspection device, a visual inspection method, and a tablet printing device capable of suppressing reflection of a reflected light source when inspecting a surface defect.SOLUTION: In a tablet printing device P, surface A of a tablet supplied from a tablet supply device is printed by a surface A printing device 7 provided in the vicinity of a first conveyance drum 2, and propriety of the printing state is inspected by a surface A visual inspection device 6. The surface A visual inspection device is composed of a surface A imaging device 61 and a surface A illumination device 62. On the basis of positional relationships between the surface A imaging device and the tablet, control is executed for the turning on and off of a first surface A light source 62a and a second surface A light source 62b that constitute the surface A illumination device.SELECTED DRAWING: Figure 1

Description

The present invention relates to a visual inspection device, a visual inspection method, and a tablet printing device. More specifically, the present invention relates to an appearance inspection apparatus, an appearance inspection method, and a tablet printing apparatus capable of suppressing reflection of a reflected light source when inspecting a surface defect of a subject.

On the surface of pharmaceutical products and capsules (hereinafter collectively referred to as "tablets" in the present specification), characters such as product numbers, product names, and ingredient contents are used to identify products and prevent accidental ingestion. Various codes consisting of and symbols are displayed. Such labeling on the tablet surface is performed by a printing process such as engraving, a transfer method, or an inkjet method.

Of these, the inkjet printing process can print on the tablet surface in a non-contact state, so it is not easily affected by the powder adhering to the tablet surface, and is also excellent in terms of hygiene. Equipment has been proposed.

For example, the printing apparatus disclosed in Patent Document 1 includes a detection imaging device for photographing a tablet before printing and an inspection imaging device for photographing a tablet after printing. The apparatus of Patent Document 1 prints various codes on the tablets conveyed on the line based on the position, posture, front and back sides, etc. of the tablets detected by the detection imaging apparatus. Further, the image pickup device for inspection is used for inspecting the printing state on each tablet and the presence or absence of foreign matter on the surface of the tablet.

Japanese Unexamined Patent Publication No. 2013-121432

The detection imaging device and the inspection imaging device used in the printing device disclosed in Patent Document 1 are provided with a lighting device for irradiating a subject, which is a tablet to be printed, with light. .. As this lighting device, an LED lighting device having excellent directivity and a predetermined spread angle (hereinafter, simply referred to as "LED") is generally adopted. Then, the surface of the subject is irradiated with the LED from an oblique direction, and the scattered light from the subject is imaged by each of the above-mentioned imaging devices.

At this time, the reflected light from the surface of the subject may be reflected on the image pickup apparatus. Then, when a surface defect exists in the region where the reflected light is reflected, the scattered light generated by being reflected from the surface defect overlaps with the light from the reflection region of the illuminating device. Therefore, even if a surface defect is present on the surface of the subject in such a region, it cannot be detected by the imaging device.

On the other hand, as another method for detecting such surface defects of the subject, the surface of the subject is illuminated with a diffuser plate or a plurality of point light sources, and the scattered light generated from the surface defects is the light of the plurality of point light sources. There is a method of detecting surface defects by suppressing the influence of reflection of a light source by detecting at a position deviated from the axis. However, it is not always a practical method because it is difficult to install a plurality of point light sources due to problems such as the space of the printing apparatus and it is necessary to control each point light source. ..

The present invention has been devised in view of the above points, and is an appearance inspection device, an appearance inspection method, and an appearance inspection method capable of suppressing reflection of a reflected light source when inspecting a surface defect of a subject. It is an object of the present invention to provide a tablet printing apparatus.

In order to achieve the above object, the visual inspection device of the present invention includes a position detecting device for detecting the position of a subject transported along a transport path from upstream to downstream on the transport path, and an appearance of the subject. An imaging device that acquires image data by imaging within a predetermined imaging region on the transport path, a first light source that irradiates a subject with illumination light from the downstream side of the imaging device, and an upstream of the imaging device. The positional relationship between the position of the subject and the image pickup device at the imaging timing by the image pickup device detected by the position detection device and the lighting device including the second light source that irradiates the subject with the illumination light from the side. A lighting control device for controlling the lighting pattern of the lighting device is provided accordingly.

Here, by providing a position detection device that detects the position of the subject transported along the transport path from the upstream to the downstream on the transport path, the absolute position of the subject to be visually inspected on the transport path is provided. The subject can be imaged at an appropriate timing by the imaging device described later.

Further, by providing an imaging device that acquires image data by imaging the appearance of the subject within a predetermined imaging region on the transport path, a region in which the entire appearance of the subject can be imaged is defined as an imaging region. The appearance of the subject can be imaged in the imaging region to acquire image data, and the presence or absence of an abnormality in the appearance of the subject can be determined based on the image data.

Further, by providing an illumination device that irradiates the subject transported along the transport path with the illumination light, it is possible to obtain the reflected light when the subject is irradiated with the illumination light. The imaging device can capture the reflected light and acquire image data of the subject.

The lighting device is composed of a first light source that irradiates the subject with illumination light from the downstream side of the imaging device, and a second light source that irradiates the subject with illumination light from the upstream side of the imaging device. As a result, the irradiation light from two directions secures a sufficient amount of light required for imaging regardless of the position of the subject with respect to the imaging device in the imaging region, and is appropriate reflected light. Can be obtained.

Further, by providing a lighting control device that controls the illumination pattern of the lighting device according to the position of the subject at the imaging timing by the imaging device detected by the position detection device and the positional relationship of the imaging device, the subject and the imaging device are provided. An appropriate amount of light can be secured depending on the positional relationship of. Therefore, in the imaging region, clear image data can always be acquired regardless of the position of the subject with respect to the imaging device.

Further, when the imaging device is a line scan camera capable of acquiring partial image data by imaging with a linear field of view substantially orthogonal to the transport path, the subject has high resolution and therefore always moves along the transport direction. It is also possible to acquire high-resolution partial image data. Therefore, even a slight abnormality present in the appearance of the subject can be detected.

Further, when controlling the illumination pattern of the lighting device according to the positional relationship between the position of the subject imaged by the imaging device detected by the position detection device and the linear field of view, the image is captured by the linear field of view of the line scan camera. It is possible to control the illumination pattern of the illumination control device in consideration of the incident angle of the reflected light from the subject.

Further, the lighting control device sets the second light source when the first light source is turned on according to the positional relationship between the transport position of the subject imaged by the image pickup device detected by the position detection device and the linear visual field. When the light is turned off and the second light source is turned on when the first light source is turned off, the reflected light incident on the image pickup apparatus is emitted according to the positional relationship between the position of the subject to be imaged and the linear visual field. It is possible to control the lighting or extinguishing of the lighting device so as to be appropriate. Further, when one light source is turned on, the other light source is turned off, so that the electricity consumption of the lighting device can be reduced.

In addition, when the transport direction is the longitudinal direction, the appearance of the subject is one side including the tip that points downstream in the transport direction with the substantially center line that divides the longitudinal direction of the subject into two, and the upstream in the transport direction. The other side including the rear end to be directed is defined, and the lighting control device turns on the first light source when acquiring the partial image data of the first region on one side including the tip of the subject by the imaging device. When the second light source is turned off, the tip portion of the subject can be illuminated by the illumination light emitted from the first light source, so that the tip portion is sufficiently reflected by the tip portion where the illumination light is difficult to reach. Light can be secured.

At this time, when the second light source is turned on together with the first light source, the reflected light emitted from the second light source and reflected by the subject interferes with the irradiation light from the first light source, so that the amount of light is strong. The partial image data becomes unclear because it becomes too large. On the other hand, when the first light source is turned off and the second light source is turned on, the irradiation light emitted from the second light source cannot irradiate a sufficient amount of light near the tip of the subject, and the partial image data is displayed. It becomes unclear.

Further, when acquiring the partial image data of the second region on one side excluding the first region of the subject, when the first light source is turned off and the second light source is turned on, the second light source is turned on. The reflected light emitted from the light source of the above and reflected by the subject is incident on the imaging device in an appropriate amount depending on the positional relationship between the imaging device and the subject, so that clear partial image data can be acquired.

That is, for example, a tablet as a subject is usually molded into a substantially elliptical shape or a substantially cylindrical shape that gently inclines from a second region to a first region with a center line as a boundary. At this time, since the reflected light emitted from the second light source and reflected in the gently inclined portion related to the second region is reflected in the transport direction, the amount of light incident on the linear field of view of the image pickup apparatus is appropriately adjusted. By doing so, clear partial image data can be acquired.

On the other hand, when the first light source is turned on when the second region is imaged, most of the reflected light emitted from the first light source and reflected in the gently inclined portion related to the second region is incident on the image pickup apparatus. When the amount of light becomes too strong, a part of the second region of the subject becomes white and blurred partial image data.

Further, when the image pickup device acquires the partial image data of the third region on the other side excluding the rear end of the subject, the reflected light emitted from the first light source and reflected by the subject is the image pickup device and the subject. Depending on the positional relationship of the sample, the amount of light becomes an appropriate amount and is incident on the imaging device, so that clear partial image data can be acquired.

That is, as described above, the tablet as a subject is molded into a substantially elliptical shape or a substantially cylindrical shape that is gently inclined from the third region to the fourth region with the center line as a boundary. At this time, the reflected light emitted from the first light source and reflected in the gently inclined portion related to the third region is reflected in the direction opposite to the transport direction, so that the amount of light incident on the linear field of view of the image pickup apparatus is large. By adjusting appropriately, clear partial image data can be acquired.

On the other hand, when the second light source is turned on when the third region is imaged, most of the reflected light emitted from the second light source and reflected in the gently inclined portion related to the third region is incident on the image pickup apparatus. When the amount of light becomes too strong, a part of the third region of the subject becomes white and blurred partial image data.

Further, when acquiring partial image data of a fourth region including the rear end of the subject and excluding the third region by the imaging device, when the first light source is turned off and the second light source is turned on. Is able to irradiate the rear end portion of the subject with the illumination light emitted from the second light source, so that sufficient reflected light can be secured for the rear end portion where the illumination light is difficult to reach.

At this time, when the first light source is turned on together with the second light source, the reflected light emitted from the first light source and reflected by the subject interferes with the irradiation light from the second light source, so that the amount of light is strong. The partial image data becomes unclear because it becomes too large. On the other hand, when the second light source is turned off and the first light source is turned on, the irradiation light emitted from the first light source cannot irradiate a sufficient amount of light near the tip of the subject, and the partial image data is displayed. It becomes unclear.

Further, when the imaging device acquires partial image data relating to N subjects from upstream to downstream in the transport direction in the imaging region, the imaging device decomposes the imaging region into N resolutions and then determines the imaging device. With the linear visual field, the partial image data of the subject can be acquired at a predetermined timing, and the illumination control of the lighting device can be performed in synchronization with the acquisition of the partial image data.

That is, once the resolution of the imaging region is defined, the timing of acquiring partial image data by the imaging device is determined based on the resolution. Further, the lighting and extinguishing control by the lighting device can be reliably switched based on the acquisition timing of the partial image data.

In order to achieve the above object, the visual inspection method of the present invention includes a step of transporting a subject along a transport path from upstream to downstream, a step of detecting the position of the subject on the transport path, and imaging. In the step of capturing the appearance of the subject in a predetermined imaging region by the apparatus and acquiring the image data and the step of acquiring the image data, the subject is irradiated with illumination light from the downstream side of the imaging apparatus. The present invention includes a step of controlling an illumination pattern of an illumination device including a first light source and a second light source that irradiates a subject with illumination light from the upstream side of the image pickup apparatus.

Here, by providing a step of transporting the subject along the transport path from the upstream to the downstream, a plurality of operations and inspection steps performed on the subject can be performed on the transport path. It is possible to streamline the work on the sample or the inspection work.

Further, by providing a step of detecting the position of the subject on the transport path, the absolute position of the subject to be visually inspected on the transport path can be grasped, which is more appropriate in the imaging step by the imaging device described later. The subject can be imaged at the timing.

Further, by providing a step of capturing the appearance of the subject in a predetermined imaging region with an imaging device and acquiring image data, a region in which the entire appearance of the subject can be imaged is defined as an imaging region, and the imaging region is defined. The appearance of the subject can be imaged and image data can be acquired, and the presence or absence of an abnormality in the appearance of the subject can be determined based on the image data.

Further, in the process of acquiring image data, by providing a step of controlling the lighting pattern of the lighting device, the lighting device can obtain the clearest image data according to the positional relationship between the subject and the imaging device. The lighting pattern can be controlled.

Further, in the step of controlling the illumination pattern, the first light source for irradiating the subject with illumination light from the downstream side of the imaging device, and the second light source for irradiating the subject with illumination light from the upstream side of the imaging device. When controlling the illumination pattern of a lighting device consisting of a light source, the irradiation light from two directions is sufficient for imaging regardless of the position of the subject with respect to the imaging device in the imaging region. It is possible to secure an appropriate amount of light and obtain an appropriate reflected light.

In order to achieve the above object, the tablet printing apparatus of the present invention has a tablet supply unit capable of storing tablets and a large number of tablet holding units on the outer peripheral surface, and supplies the tablet holding unit from the tablet supply unit. A printing device that prints on the exposed surface of the tablet in the tablet holding portion, which is arranged near the outer peripheral surface of the transport drum to which the transferred tablets are transferred and is transported along the transport path by the rotation of the transport drum. A tablet printing device including the tablet printing device, which is arranged near the outer peripheral surface on the downstream side of the printing device and inspects the appearance of the printed tablet in the tablet holding portion which is transported by the rotation of the transport drum. In the visual inspection device, the position detection device for detecting the position of the tablet transported along the transport path from the upstream to the downstream on the transport path and the appearance of the printed tablet in the tablet holding portion are predetermined. An imaging device that acquires image data by imaging in the imaging region, a first light source that irradiates the tablet with illumination light from the downstream side of the imaging device, and an illumination light that illuminates the tablet from the upstream side of the imaging device. The illumination pattern of the illumination device is controlled according to the positional relationship between the tablet position and the image pickup device at the imaging timing by the image pickup device detected by the position detection device and the illumination device including the second light source that irradiates the tablet. It is equipped with a lighting control device.

Here, the tablet printing apparatus has a tablet supply unit capable of storing tablets, and a transfer drum having a large number of tablet holding units on the outer peripheral surface and transferring the tablets supplied from the tablet supply unit to the tablet holding unit. A printing device that is arranged near the outer peripheral surface of the drum and prints on the exposed surface of the tablet in the tablet holding portion that is transported along the transport path by the rotation of the transport drum, and is arranged near the outer peripheral surface on the downstream side of the printing device. By providing an appearance inspection device for inspecting the appearance of the printed tablet in the tablet holding portion transported by the rotation of the transport drum, the tablets supplied from the tablet supply unit and transported by the transport drum are predetermined. In addition to being able to print the characters and symbols of, the appearance inspection device can inspect for abnormalities in appearance including the printed state of tablets.

In addition, by providing a position detection device that detects the position of the tablet transported along the transport path from the upstream to the downstream on the transport path, the absolute position of the tablet to be visually inspected on the transport path can be grasped. , The tablet can be imaged at an appropriate timing by the imaging device described later.

Further, by providing an imaging device that captures the appearance of the tablet within a predetermined imaging region and acquires image data, a region in which the entire appearance of the tablet can be imaged is defined as an imaging region, and the tablet is within the imaging region. The appearance can be imaged to acquire image data, and the presence or absence of abnormalities in the appearance of the tablet can be determined based on the image data.

Further, by providing an illumination device that irradiates the tablet with illumination light along the transport path, it is possible to obtain the reflected light when the tablet is irradiated with the illumination light. The imaging device can capture the reflected light and acquire image data of the tablet.

Further, the illumination device is composed of a first light source that irradiates the tablet with illumination light from the downstream side of the image pickup device and a second light source that irradiates the tablet with illumination light from the upstream side of the image pickup device. As a result, the irradiation light from two directions secures a sufficient amount of light required for imaging regardless of the position of the tablet with respect to the imaging device in the imaging region, and obtains appropriate reflected light. be able to.

Further, by providing an illumination control device that controls the illumination pattern of the illumination device according to the positional relationship between the tablet position at the imaging timing by the image pickup device detected by the position detection device and the image pickup device, the positions of the tablet and the image pickup device are provided. An appropriate amount of light can be secured depending on the relationship. Therefore, in the imaging region, clear image data can always be acquired regardless of the position of the tablet with respect to the imaging device.

The visual inspection apparatus, visual inspection method, and tablet printing apparatus according to the present invention can suppress reflection of a reflected light source when inspecting a surface defect of a subject.

It is an overall schematic view of the tablet printing apparatus which concerns on embodiment of this invention. It is an overall schematic view of the appearance inspection apparatus which concerns on embodiment of this invention. It is a block diagram of the appearance inspection apparatus which concerns on embodiment of this invention. It is a figure explaining the imaging region of a tablet. It is a schematic diagram which shows the situation which a visual inspection is performed. It is a time chart of a lighting device. It is the image data of the tablet imaged by the image pickup apparatus.

Hereinafter, embodiments of the present invention will be described with reference to the drawings for the purpose of understanding the present invention. For convenience of explanation in each figure, when the tablet printing device is installed on the installation surface, the direction upward from the installation surface of the tablet printing device is upward, and the opposite direction of the upward direction is downward, upward, and downward. The axial direction represented by is defined as the vertical direction, the axial direction perpendicular to the vertical direction is defined as the horizontal direction, and the rotation direction of each drum constituting the tablet printing apparatus is defined as the transport direction.

Further, in the following embodiments, an example in which the visual inspection apparatus of the present invention is applied to a tablet printing apparatus will be described, but the present invention is not necessarily limited to the embodiment, and the visual inspection apparatus is any electronic component, food, or the like. It shall also be applicable when inspecting the appearance. The tablet defined in the embodiment of the present invention is a doublet tablet having a major axis of approximately 1.00 cm to 3.00 cm and a minor axis of approximately 0.50 cm to 1.00 cm and having a substantially elliptical cross section. It is not limited to. For example, it may be a capsule tablet composed of a cap and a body and having a substantially elliptical cross section, a formulation having a substantially circular shape in a plan view, or the like.

First, the configuration of the tablet printing device P to which the visual inspection device according to the embodiment of the present invention is applied will be described with reference to FIG. The tablet printing device P determines the front and back sides of the tablet and prints on one or both sides of the front and back sides of the tablet such as a pharmaceutical product as a subject, and selects whether the tablet is a good product or a defective product. As shown in FIG. 1, a supply drum 1, a first transfer drum 2, a second transfer drum 3, and an extraction drum 4 are provided.

Above the supply drum 1, a tablet supply device 5 including a hopper 51 for storing tablets to be printed and a chute 52 for supplying the tablets stored in the hopper 51 to the supply drum 1 is provided. There is.

Below the take-out drum 4, a tablet judged to be non-defective based on the printing state and the inspection result of the presence or absence of foreign matter by the A-side visual inspection device 6 and the B-side visual inspection device 8 described later is sent to a subsequent process. A tablet discharging device 10 including a belt conveyor 101 and a collecting device 102 for collecting tablets determined to be defective is installed.

Here, it is not always necessary to include the supply drum 1. The tablets stored in the hopper 51 may be directly supplied to the first transport drum 2 by the chute 52.

Further, it is not always necessary to include the take-out drum 4. For example, by giving the second transfer drum 3 the same function as the take-out drum 4, the tablets may be transferred from the second transfer drum 3 to the belt conveyor 101 and the collection device 102.

Each of the above-mentioned drums has a large number of holes (not shown) formed on the outer peripheral surface for adsorbing the tablets, and the adjacent drums rotate in the opposite direction in synchronization with each other, and the tablets are formed between the drums. By delivering the tablets, the tablets can be transported to a subsequent process.

In the delivery of tablets in each drum, the front and back surfaces of the tablets (hereinafter, the front surface is defined as "A side" and the back surface is defined as "B side") are reversed. For example, if the A side of the first transport drum 2 is exposed, when it is delivered to the second transport drum 3, the B surface, which is the opposite surface, is exposed, and then it is delivered to the take-out drum 4. And the A side will be exposed again.

In the vicinity of the first transport drum 2, the A-side printing device 7 for printing various codes consisting of letters, symbols, etc. on the exposed surface of the tablet (here, the A-side) in order from the upstream side in the transport direction. The A-side visual inspection device 6 for inspecting the printed state of the A-side and the presence or absence of foreign matter is provided.

As shown in FIG. 2, the A-side visual inspection device 6 includes an A-side imaging device 61, which is an inspection camera that images the A-side, and an A-side illumination for irradiating the A-side of the tablet to be imaged with light. It has a device 62. The A-plane illumination device 62 is a first unit that uses an LED as a light source and is at a symmetrical position with the A-plane imaging device 61 in between, and irradiates the tablet with illumination light at a predetermined angle (for example, approximately 45 degrees) from the downstream side. It is composed of an A-plane light source 62a and a second A-plane light source 62b that irradiates the tablet with illumination light at a predetermined angle (for example, about 45 degrees) from the upstream side.

The A-side imaging device 61 captures an image for one line at an imaging point by means of a strip-shaped (straight-line) field of view (hereinafter, referred to as “linear field of view”) extending in a width direction substantially orthogonal to the transport direction. This is a line sensor camera that continuously captures images for a predetermined imaging area.

Here, the A-side imaging device 61 does not necessarily have to be a line sensor camera. For example, an area camera in which the image pickup elements are arranged in a vertical and horizontal planes and can obtain an image relating to a predetermined two-dimensional imaging region may be used. However, from the viewpoint of imaging the tablets on the first transport drum 2 rotating at high speed with a constant high resolution, the A-side imaging device 61 is preferably a line sensor camera.

Further, the A-side lighting device 62 does not necessarily have to be an LED. It can be appropriately selected from known light sources such as halogen lamps and fluorescent lamps. However, it is preferable to use an LED having excellent controllability in order to obtain a constant amount of light with low power consumption and to support switching control between lighting and extinguishing at high speed.

Further, the first A-side light source 62a and the second A-side light source 62b do not necessarily have to be symmetrically arranged with the A-plane imaging device 61 interposed therebetween. For example, the mounting angle of each light source may be adjusted so that the irradiation angle of the irradiation light emitted from the first A-side light source 62a and the irradiation angle of the second A-side light source 62b are different.

A score line imaging device (not shown) for confirming the direction of the score line may be separately provided on the upstream side of the A-side printing device 7, for example, in a tablet having a score line formed substantially in the center. By providing the secant line imaging device, it is possible to appropriately change the printing direction of the A-side printing device 7 according to the direction of the secant line.

In the vicinity of the second transport drum 3, as in the case of the first transport drum 2, various codes consisting of letters, symbols, etc. on the exposed surface of the tablet (here referred to as the B surface) in order from the upstream side in the transport direction. It has a B-side printing device 9 for printing, and a B-side visual inspection device 8 for inspecting the printing state of the B-side and the presence or absence of foreign matter. Since the B-side visual inspection device 8 has the same configuration as the A-side visual inspection device 6, detailed illustration is omitted.

The B-side visual inspection device 8 includes a B-side imaging device 81, which is an inspection camera that images the B-side, and a B-side lighting device 82 for irradiating the B-side of the tablet to be imaged with light. .. The B-plane lighting device 82 uses an LED as a light source, and the first B-plane light source 82a, which irradiates the tablet with illumination light at a predetermined angle (for example, about 45 degrees) from the downstream side of the B-plane imaging device 81, upstream. It is composed of a second B-plane light source 82b that irradiates the tablet with illumination light at a predetermined angle (for example, about 45 degrees) from the side.

Next, the visual inspection apparatus according to the embodiment of the present invention will be described. As described above, since the A-side visual inspection device 6 and the B-side visual inspection device 8 as the visual inspection device have substantially the same configuration, the A-side visual inspection device 6 will be described here as an example.

As described above, the A-side visual inspection device 6 mainly includes the A-side imaging device 61, the A-side lighting device 62 including the first A-side light source 62a and the second A-side light source 62b, and the first transport. It is composed of an A-side position detecting device 63 (not shown) for detecting the position of the tablet on the drum 2.

In the embodiment of the present invention, the A-plane position detecting device 63 uses an incremental encoder. The incremental encoder has a well-known structure, and outputs a number of pulse signals proportional to the amount of rotation (rotation angle) as the permanent magnet synchronous motor (not shown) rotates.

Here, the A-plane position detecting device 63 does not necessarily have to be an incremental encoder. For example, it may be an absolute encoder capable of detecting the absolute position of the tablet transported on the transport path. In the embodiment of the present invention, the absolute position of each tablet on the transport path is detected by converting the signal of the origin detected by the incremental encoder into an absolute position as a reference.

FIG. 3 is a block diagram constituting the A-side visual inspection device 6. In the A-side imaging region setting unit 64, a predetermined imaging region RS is uniquely set based on the major axis of the tablet, for example, as shown in FIG. 4, and the A-side imaging apparatus 61 is within the range of the imaging region RS. It is possible to arbitrarily set the number of partial image data to be captured.

The A-side position detecting device 63 outputs pulse signals to the A-side imaging device 61 and the A-side lighting device 62 at predetermined intervals. When the A-side imaging device 61 receives the pulse signals at predetermined intervals output from the A-side position detecting device 63, the A-plane imaging device 61 performs imaging for each line at the imaging point. In the embodiment of the present invention, imaging is performed for each pulse corresponding to the major axis of the tablet defined in advance, and a total of 500 partial image data are captured from the start point to the end point of the imaging region.

Here, the A-side imaging device 61 does not necessarily have to start imaging based on the pulse signal from the A-plane position detecting device 63. The origin position for imaging may be determined in advance, and imaging may be performed at regular intervals according to the rotation speed of the first transport drum 2.

Further, the imaging timing by the A-side imaging device 61 and the number of partial image data to be captured in the imaging region RS are not necessarily limited to the above-mentioned ranges. The imaging timing and the number of partial image data to be captured can be appropriately changed depending on the size of the tablet, the size of the characters printed on the A side or the B side of the tablet, and the like.

The A-plane image processing unit 65 performs image processing based on the partial image data in the imaging region RS acquired by the A-plane imaging device 61 and synthesizes the image data into one image data, and the image data is the A-plane. It is stored in the storage device 66.

The A-side illumination device 62 has a first A-side light source 62a and a first A-side light source 62a according to the positional relationship between the tablet and the linear field of view of the A-side image pickup device 61 based on the pulse signal from the A-side position detection device 63. Lighting control for turning on or off the A-side light source 62b of No. 2 is performed.

Here, it is not always necessary for the A-side lighting device 62 to control lighting or extinguishing based on the pulse signal from the A-side position detecting device 63. The origin position at which the illumination control is started is determined in advance, and the illumination control is performed according to the rotation speed of the first transport drum 2, or the illumination control is performed by receiving a synchronization signal from the A-side imaging device 61. You may.

As shown in FIG. 4, the tablet T to be imaged has a front end pointing to the downstream side in the transport direction and a rear end pointing to the upstream side in the transport direction with the major axis substantially center line O as a boundary. As described above, the A-plane imaging device 61 captures partial image data for each pulse as a pulse signal from the A-plane position detecting device 63 from the start point to the end point of the imaging region RS, and 500 pieces in the range of the imaging region RS. Import partial image data.

At this time, the A-side illumination device 62 extends from the downstream to the upstream as a pulse signal from the A-side position detection device 63 from the start point to the end point of the imaging region RS at intervals of 125 pulses, and the first region R1 and the second region R2. , The third region R3 and the fourth region R4 are divided, and the illumination patterns of the first A-side light source 62a and the second A-side light source 62b are changed according to each region.

Here, in the illumination pattern of the A-side illumination device 62, the pulse signal from the A-side position detection device 63 does not necessarily have to be changed at intervals of approximately 125 pulses. The lighting pattern can be appropriately changed depending on the size of the tablet T to be visually inspected and the like.

Hereinafter, control of lighting and extinguishing of the A-side lighting device 62 will be described based on the schematic diagram of FIG. 5 and the time chart of FIG.

<Abbreviated range of 0 to 125 pulses>
As shown in FIG. 5A, in the first region R1 of approximately 0 to 125 pulses as the pulse signal from the A-side position detecting device 63, the linear visual field of the A-side imaging device 61 is the tip portion of the tablet T. To image. At this time, due to the positional relationship between the tablet T and the A-side lighting device 62, the first A-side light source 62a on the downstream side is turned on and the second A-side light source 62b on the upstream side is turned off to turn off the tablet T. The tip of the image is irradiated, and the A-side imaging device 61 can obtain sufficient reflected light.

For example, when the first A-side light source 62a is turned off and the second A-side light source 62b is turned on, the irradiation light emitted from the second A-side light source 62b does not reach the vicinity of the tip of the tablet T, and the tablet. Since the amount of light is insufficient near the tip of T, clear partial image data cannot be obtained.

On the other hand, when the first A-plane light source 62a and the second A-plane light source 62b are turned on at the same time, the amount of light becomes too strong due to the interference of the irradiation lights from both light sources. Clear partial image data may not be obtained.

<Range of approximately 125-250 pulses>
As shown in FIG. 5B, in the second region R2 of approximately 125 to 250 pulses as the pulse signal from the A-plane position detecting device 63, the first A-plane light source 62a is turned off and the second A-plane is turned off. The reflected light emitted from the second A-side light source 62b by turning on the light source 62b and reflected by the tablet T becomes an appropriate amount of light depending on the positional relationship between the A-side imaging device 61 and the tablet T, and the A-side imaging device 61. Since it is incident on the light source, clear partial image data can be obtained.

That is, the reflected light emitted from the second A-plane light source 62b and reflected in the gently inclined portion related to the second region R2 is reflected in the transport direction, so that it is incident on the linear field of view of the A-plane imaging device 61. Clear partial image data can be obtained by appropriately adjusting the amount of light to be emitted.

On the other hand, when the first A-side light source 62a is turned on when the second region R2 is imaged, the reflected light emitted from the first A-side light source 62a and reflected in the gently inclined portion related to the second region R2. Most of the data is incident on the A-side imaging device 61 and the amount of light becomes too strong, so that a part of the second region R2 of the tablet T becomes white and blurred partial image data.

<Range of approximately 250 to 375 pulses>
As shown in FIG. 5C, in the third region R3 of approximately 250 to 375 pulses as the pulse signal from the A-plane position detecting device 63, the first A-plane light source 62a is turned on and the second A-plane is turned on. By turning off the light source 62b, the reflected light emitted from the first A-side light source 62a and reflected by the tablet T becomes an appropriate amount of light depending on the positional relationship between the A-side image pickup device 61 and the tablet T, and the A-side image pickup device 61. Since it is incident on the light source, clear partial image data can be obtained.

That is, the reflected light emitted from the first A-plane light source 62a and reflected in the gently inclined portion related to the third region R3 is reflected in the transport direction, so that it is incident on the linear field of view of the A-plane imaging device 61. Clear partial image data can be obtained by appropriately adjusting the amount of light to be emitted.

On the other hand, when the second A-side light source 62b is turned on when the third region R3 is imaged, the reflected light emitted from the second A-side light source 62b and reflected in the gently inclined portion related to the third region R3. Most of the data is incident on the A-side imaging device 61 and the amount of light becomes too strong, so that a part of the third region R3 of the tablet T becomes white and blurred partial image data.

<Range of approximately 375 to 500 pulses>
As shown in FIG. 5D, in the fourth region R4 of approximately 375 to 500 pulses as the pulse signal from the A-side position detecting device 63, the linear visual field of the A-side imaging device 61 is the rear end of the tablet T. Image the part. At this time, due to the positional relationship between the tablet T and the A-side lighting device 62, the second A-side light source 62b on the upstream side is turned on and the first A-side light source 62a on the downstream side is turned off to turn off the tablet T. The tip of the image is irradiated, and the A-side imaging device 61 can obtain sufficient reflected light.

For example, when the second A-side light source 62b is turned off and the first A-side light source 62a is turned on, the irradiation light emitted from the first A-side light source 62a does not reach the vicinity of the rear end of the tablet T. The amount of light in the vicinity of the tip of the tablet T is insufficient, and clear partial image data cannot be obtained.

On the other hand, when the first A-plane light source 62a and the second A-plane light source 62b are turned on at the same time, the amount of light becomes too strong due to the interference of the irradiation lights from both light sources. There is a possibility that clear partial image data cannot be obtained.

FIG. 7 shows actual image data captured by the A-side imaging device 61. FIG. 7A is image data when the first A-side light source 62a and the second A-side light source 62b of the A-side lighting device 62 are constantly lit. According to FIG. 7A, there are crescent-shaped white blurry portions in the portion of the tablet T near the tip of the A surface (second region) and the portion near the rear end (third region), and halation. Can be confirmed to be causing.

Further, in FIG. 7B, the first A-side light source 62a is always turned off, the second A-side light source 62b is turned off in the first region R1, is lit in the second region R2, and is lit in the third region R3. This is the image data when the light is turned off and the light is turned on in the fourth area R4. In the second region R2, by turning on only the second A-side light source 62b, clear image data without halation can be obtained. Further, in the fourth region R4, by irradiating the rear end of the tablet T in the transport direction with the second A-side light source 62b, image data clear enough to clearly confirm the contour of the rear end can be obtained. Obtainable.

Further, in FIG. 7C, the first A-side light source 62a is turned on in the first area R1, turned off in the second area R2, turned on in the third area R3, turned off in the fourth area R4, and so on. This is image data when the second A-side light source 62b is constantly lit.

First, in the first region R1, both the first A-side light source 62a and the second A-side light source 62b are turned on, so that the amount of light becomes too strong and a semicircle is formed on the downstream side of the first region R1. The whitish line of is reflected, and the image data becomes white and blurry. Further, in the second region R2, by turning on only the second A-side light source 62b, clear image data without halation can be obtained. Further, in the third region R3, the first A-side light source 62a and the second A-side light source 62b are turned on at the same time, so that a crescent-shaped white and blurred portion exists, causing halation. You can check. Further, in the fourth region R4, only the second A-side light source 62b is lit, and it is possible to obtain clear image data to the extent that the contour of the rear end can be clearly confirmed.

As described above, it can be confirmed that by alternately controlling the lighting and extinguishing of the first A-side light source 62a and the second A-side light source 62b, clear image data in which halation does not occur in the entire region can be obtained. ..

As described above, the visual inspection apparatus, the visual inspection method, and the tablet printing apparatus according to the present invention can suppress the reflection of the reflected light source when inspecting the surface defects of the subject.

P Tablet printing device 1 Supply drum 2 1st transfer drum 3 2nd transfer drum 4 Extraction drum 5 Tablet supply device 51 Hopper 52 Shoot 6 A side visual inspection device 61 A side image pickup device 62 A side illumination device 62a 1st A-side light source 62b Second A-side light source 63 A-side position detection device 64 A-side imaging area setting unit 65 A-side image processing unit 66 A-side storage unit device 7 A-side printing device 8 B-side visual inspection device 81 B-side imaging Device 82 B-side illumination device 82a First B-side light source 82b Second B-side light source 83 B-side position detection device 9 B-side printing device 10 Tablet discharge device 101 Belt conveyor 102 Recovery device T Tablet RS Imaging area R1 First Area R2 2nd area R3 3rd area R4 4th area

Claims (9)

A position detection device that detects the position of the subject transported along the transport path from upstream to downstream on the transport path, and
An imaging device that acquires image data by imaging the appearance of the subject within a predetermined imaging area on the transport path, and
An illumination device including a first light source that irradiates the subject with illumination light from the downstream side of the imaging device, and a second light source that irradiates the subject with illumination light from the upstream side of the imaging device.
An appearance inspection device including a lighting control device that controls the lighting pattern of the lighting device according to the position of a subject at the imaging timing by the imaging device detected by the position detecting device and the positional relationship of the imaging device. The imaging device is a line scan camera capable of acquiring partial image data by imaging with a linear field of view substantially orthogonal to the transport path.
The visual inspection apparatus according to claim 1, wherein the illumination pattern of the illumination apparatus is controlled according to the positional relationship between the position of the subject imaged by the imaging apparatus detected by the position detection apparatus and the linear visual field. The appearance according to claim 2, wherein the lighting control device turns off the second light source when the first light source is turned on, and turns on the second light source when the first light source is turned off. Inspection device. When the transport direction is the longitudinal direction, the appearance of the subject points to one side including the tip that points downstream in the transport direction with the substantially center line that divides the longitudinal direction of the subject into two, and points upstream in the transport direction. The other side, including the trailing edge, is defined
When the illumination control device acquires partial image data of a predetermined first region on one side including the tip of the subject by the imaging device, the lighting control device turns on the first light source and turns on the second light source. Turns off,
When the image pickup apparatus acquires partial image data of a predetermined second region on one side of the subject excluding the first region, the first light source is turned on and the second light source is turned on. And
When the image pickup apparatus acquires partial image data of a predetermined third region on the other side excluding the rear end of the subject, the first light source is turned on and the second light source is turned off.
When the image pickup apparatus acquires partial image data of a predetermined fourth region including the rear end of the subject and excluding the third region, the first light source is turned off and the second light source is turned off. The visual inspection apparatus according to claim 2 or 3, which is lit. The imaging device acquires partial image data of N subjects (N is a natural number) from upstream to downstream in the transport direction in the imaging region.
The first region corresponds to a range in which less than about N / 4 partial image data are acquired after the imaging of the subject by the imaging device is started.
The second region corresponds to a range in which partial image data of approximately N / 4 or more and less than approximately N / 2 is acquired after the start of imaging of the subject by the imaging device.
The third region corresponds to a range in which partial image data of approximately N / 2 or more and less than approximately 3N / 4 is acquired after the start of imaging of the subject by the imaging device.
The appearance according to claim 4, wherein the fourth region is approximately 3N / 4 or more from the start of imaging of the subject by the imaging device, and corresponds to the range from the acquisition of N partial image data. Inspection equipment. The process of transporting the subject along the transport path from upstream to downstream, and
The process of detecting the position of the subject on the transport path and
A step of capturing an image of a subject detected in the step of detecting the position of the subject in a predetermined imaging region with an imaging device and acquiring image data, and a step of acquiring image data.
In the step of acquiring the image data, the first light source that irradiates the subject with illumination light at a predetermined angle from the downstream side of the imaging device, and the subject at a predetermined angle from the upstream side of the imaging device. A visual inspection method comprising a step of controlling an illumination pattern of an illumination apparatus including a second light source for irradiating illumination light. The step of controlling the lighting pattern of the lighting device is
The visual inspection method according to claim 6, wherein the second light source is turned off when the first light source is turned on, and the second light source is turned on when the first light source is turned off. When the transport direction is the longitudinal direction, the appearance of the subject points to one side including the tip that points downstream in the transport direction with the substantially center line that divides the longitudinal direction of the subject into two, and points upstream in the transport direction. The other side, including the trailing edge, is defined
In the step of controlling the illumination pattern of the illumination device, when the image pickup apparatus acquires image data of a predetermined first region on one side including the tip of the subject, the first light source is turned on. Turn off the second light source
When the image pickup device acquires image data of a predetermined second region on one side of the subject excluding the first region, the first light source is turned off and the second light source is turned on. ,
When acquiring image data of a predetermined third region on the other side excluding the rear end of the subject by the imaging device, the first light source is turned on and the second light source is turned off.
When the image pickup device acquires image data of a predetermined fourth region including the rear end of the subject and excluding the third region, the first light source is turned off and the second light source is turned on. The visual inspection method according to claim 6 or 7. A tablet supply unit that can store tablets and
A transport drum having a large number of tablet holding portions on the outer peripheral surface and to which the tablets supplied from the tablet feeding portion are transferred to the tablet holding portions.
A printing device that is arranged near the outer peripheral surface of the transport drum and prints on the exposed surface of the tablet in the tablet holding portion that is transported along the transport path by the rotation of the transport drum.
In a tablet printing device including a visual inspection device arranged near the outer peripheral surface on the downstream side of the printing device and inspecting the appearance of a printed tablet in the tablet holding portion which is conveyed by rotation of the transport drum.
The visual inspection device is
A position detection device that detects the position of tablets transported along the transport path from upstream to downstream on the transport path, and
An imaging device that acquires image data by imaging the appearance of the printed tablet in the tablet holding portion within a predetermined imaging region on the transport path.
An illumination device including a first light source that irradiates the tablet with illumination light from the downstream side of the image pickup device, and a second light source that irradiates the tablet with illumination light from the upstream side of the image pickup device.
A tablet printing device including a tablet printing device that controls a lighting pattern of the lighting device according to a position of a tablet at an imaging timing by the imaging device detected by the position detecting device and a positional relationship of the imaging device.

Images