JP3954083B2 - Appearance inspection method and apparatus - Google Patents

Description

  The present invention relates to an appearance inspection method for determining the quality of an appearance of a small article such as a tablet, and an appearance inspection apparatus using this method.

  Conventionally, as a method for inspecting the appearance of small articles such as tablets (hereinafter referred to as “inspection object”), the inspection object is dropped vertically, and the falling inspection object is imaged by an imaging means such as a CCD camera, Appearance inspection methods are known in which image processing is performed on the obtained imaging data to determine the quality of an inspection object (for example, chipping or cracking) (for example, see Patent Documents 1 and 2). ).

  According to the appearance inspection method described in Patent Document 1, an object to be vertically dropped is imaged by an imaging means such as a CCD camera from a horizontal front position, and the object is inspected by image processing based on the obtained single image. The quality of the appearance is determined.

  Further, in the appearance inspection method described in Patent Document 2, a reflecting plate (mirror) having a cross-section “<” shape is disposed opposite to a position opposite to the imaging unit with a fall path of an inspection object interposed therebetween. When the object to be inspected passes through the front of the reflector, the object to be inspected is reflected from the front image taken directly from the front in the horizontal direction and from the reflector having a cross-section "<" A total of three images, a left rear image and a right rear image, are obtained simultaneously, and the quality of the appearance of the inspection object is determined by image processing based on these three images.

JP 2001-311691 A (all pages, all figures) Japanese Patent Laying-Open No. 2005-172608 (all pages, all figures)

  In the case of the appearance inspection method described in Patent Document 1, the quality of the appearance of the object to be inspected is determined based on one front image taken directly from the front in the horizontal direction. For this reason, the appearance inspection cannot be performed on the rear surface, the left and right side surfaces, the upper and lower side surfaces, and the like that are not imaged. In order to perform an appearance inspection on the entire peripheral surface of the inspection object using the appearance inspection method described in Patent Document 1, the inspection object that naturally falls while changing its posture irregularly is measured several times during the fall. However, even if such a method is adopted, there is no guarantee that the appearance inspection has been definitely performed on the entire circumferential surface.

  In the case of the appearance inspection method described in Patent Document 2, a total of three images including a front image captured directly from the front in the horizontal direction and left and right side images projected and reflected on a reflector having a cross-section “<” shape. Since the quality of the appearance of the object to be inspected is determined based on the above image, it is possible to perform a more accurate appearance inspection than the appearance inspection method described in Patent Document 1. However, in order to perform an appearance inspection of the entire outer peripheral surface of a thick three-dimensional object to be inspected, such as a tablet, by one image processing, the front surface, the back surface, the upper and lower side surfaces, and the left and right side surfaces 6 In the case of the appearance inspection method described in Patent Document 2, a front image captured directly from the front in the horizontal direction and a reflection plate having a cross-section “<” shape are reflected and reflected. Since only the left and right side and back images can be obtained, and the upper and lower side images cannot be obtained, it has been difficult to accurately inspect the entire outer peripheral surface of the object to be inspected with one imaging.

The present invention has been made to solve the above problems, the front of the object to be inspected, rear, upper and lower sides, it is possible to simultaneously capture images of the total of six surfaces of the right and left side surfaces, imaging of these six surfaces It is an object of the present invention to provide an appearance inspection method capable of performing an extremely accurate and complete appearance inspection with one imaging on the entire peripheral surface of an object to be inspected by using an image, and an appearance inspection apparatus using the same. Is.

In order to achieve the above object, the visual inspection method of the present invention images the inspection object being transported by the imaging means, and performs image processing on the image data of the obtained captured image to determine whether the appearance of the inspection object is good or bad. In the visual inspection method, a vertical drop part for naturally dropping the inspection object according to gravity is provided in the middle of the conveyance path, and an imaging point of the inspection object is set in the vertical dropping part, and the imaging point An imaging means consisting of an area sensor is arranged at the front position in the horizontal direction directly opposite to the imaging point, and four side mirrors are arranged around the imaging point so as to surround the imaging point at right angles to the vertical and horizontal positions of the imaging point. In addition, a single rear-view mirror having a cross-section “<” shape is arranged on the back side of the imaging point, and the object to be inspected is predetermined at the vertical drop portion. It was naturally dropped to correct the attitude, when the object to be inspected come beat該落is located at the imaging point, and vertical and horizontal four sides image of the object reflected from the four side surfaces mirrors , a rear image of the object coming is reflected toward the front side by the reflection mirror, the imaging means comprising an image of a total of six surfaces of the front image of the object to be viewed directly from the front position from the area sensor Image at the same time,
The quality of the appearance of the object to be inspected is determined using the image data of the six images captured at the same time.

In addition, the appearance inspection apparatus of the present invention images the inspection object being transported by the imaging means, and determines whether the appearance of the inspection object is good or not by performing image processing on the image data of the obtained captured image. In the appearance inspection apparatus, the vertical dropping means for the inspection object provided in the middle of the conveyance path, and the reflection means arranged at the imaging point of the inspection object set at a predetermined position directly below the vertical dropping means And an imaging means comprising an area sensor for imaging the inspection object from the horizontal front position when the inspection object falling vertically is positioned at the imaging point, and provided below the reflection means provided, and a good-defective sorting means for distributing an inspection object falling down according to the result of the quality determination of appearance into non-defective products and defective products, the vertical drop section, the inspection object being conveyed in a predetermined posture Correction The reflecting means is arranged perpendicularly to the vertical position and the horizontal position of the imaging point so as to surround the imaging point, and the upper and lower sides of the outer peripheral side surface of the inspection object positioned at the imaging point. Four side mirrors that reflect the four images on the left and right sides toward the imaging unit, and the rear image of the inspection object that is disposed on the rear side of the imaging point and is positioned at the imaging point, is directed toward the imaging unit. It is characterized by comprising a single rear-view mirror having a cross-section “<” shape to be reflected .

According to the appearance inspection method of the present invention, four side mirrors arranged orthogonally to the upper and lower and left and right positions of the imaging point, and one mirror having a cross-section “<” shape arranged on the back side of the imaging point. The five images of the back, upper and lower sides, and left and right sides of the object to be inspected falling are reflected toward the image pickup means, and the reflected five images and the front image that is directly visually recognized are measured. Since the six images are simultaneously captured by the imaging means, image processing is performed using the image data of these six captured images, so that the entire circumferential surface of the object to be inspected is extremely accurate with a single imaging. A complete visual inspection can be performed.

Further, according to the appearance inspection apparatus of the present invention, the four mirrors arranged orthogonally to the vertical position and the horizontal position of the imaging point and the single rear-view mirror having a cross-section “<” shape arranged on the back side. Imaging means consisting of an area sensor arranged at the front position in the horizontal direction of the imaging point, so that a total of six images of the front, back, top and bottom sides, and left and right sides of the object to be inspected are captured. Images can be taken simultaneously by the means. For this reason, by performing image processing using the image data of these six captured images, an extremely accurate and complete appearance inspection can be performed on the entire peripheral surface of the inspection object, and the accuracy of the appearance inspection is greatly improved. Can be made. In addition, since the appearance inspection of the object to be inspected, which has been difficult with conventional single imaging, can be completed with a single imaging, the time required for the visual inspection can be shortened, and the manufacture of small articles such as tablets can be performed. Efficiency can be improved.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings , but before that, reference embodiments of the present invention necessary for understanding the present invention will be described first.

1 to 3 show an appearance inspection apparatus according to a reference embodiment of the present invention. FIG. 1 is a schematic side view showing the overall configuration of the apparatus, FIG. 2 is a schematic perspective view showing the arrangement of reflecting means and a CCD camera provided in the middle of the tablet dropping path, and FIG. FIG. 3B is a schematic cross-sectional view taken along the line II in FIG. 3A. FIG.

As shown in FIG. 1, the visual inspection apparatus according to this reference form aligns the hopper 11 that is loaded with the tablets S that are inspection objects and the tablets that are loaded into the hoppers 11 and discharges them at regular intervals. The alignment device 12, the vibration feeder 13 that conveys the tablets discharged from the alignment device 12 at regular intervals toward the vertical dropping chute 14 while correcting the tablets to a fixed posture, and the inspection object sent through the vibration feeder 13. A vertical dropping chute (vertical dropping means) 14 that vertically drops the tablet S in a predetermined posture while maintaining a predetermined posture, and a predetermined distance in the vertical direction is located below the vertical dropping chute 14. And a collecting chute 15 arranged.

  Between the collecting chute 15 and the vertical dropping chute 14, reflecting means 16 for taking out a total of six images including a front image, a rear image, and four outer peripheral side surfaces of the falling tablet S is installed. A CCD camera (imaging) comprising an area sensor for directly capturing a front image of the tablet S at the front position in the horizontal direction of the reflecting means 16 and capturing a reflected image of the tablet S sent from the reflecting means 16. Means) 17 is installed.

  Also, below the collection chute 15, a good / defective product sorter (non-defective product / defective product sorting means) 18 for further separating good products from defective products, and a belt for carrying out the sorted good products to the next process. A conveyor 19 and a defective product storage box 20 for storing defective products are provided.

As shown in detail in FIGS. 2 and 3, the reflecting means 16 in the reference embodiment includes four side mirrors 16 a to 16 d having a square shape in plan view, and one sheet having a cross-section “<” shape. And a rear mirror 16e.

  Of these mirrors, the four side mirrors 16a to 16d are 45 degrees above the right, 45 degrees below the right, 45 degrees below the left, and 45 degrees to the left with the imaging point P set in the middle of the vertical drop path of the tablet S as the center. The mirror surface is located at each of the positions 45 degrees upward and left obliquely, and the mirror surface thereof is arranged toward the imaging point P. Further, the light beam emitted from the imaging point P is reflected by the mirror surface of each mirror and is reflected on the CCD camera 17. Inclined toward the CCD camera 17 side by a predetermined angle so as to be incident on the CCD camera 17 side. The size of the side mirrors 16 a to 16 d may be any size as long as the entire side surface of the tablet S can be projected and reflected toward the CCD camera 17.

  On the other hand, the rear-view mirror 16e having a cross-section “<” shape is disposed opposite to the CCD camera 17 with the imaging point P interposed therebetween. Further, the upper mirror surface of the mirror surface having a cross-section “<” shape is arranged so as to be located immediately behind the imaging point P, and the back image of the tablet S reflected on the upper mirror surface is directed toward the lower mirror surface. The mirror surface bending angle θ is set so as to be reflected and further reflected from the lower mirror surface toward the CCD camera 17. The size of the rear mirror 16e may be any size as long as the entire back surface of the tablet S can be projected and reflected toward the CCD camera 17.

When the reflecting means 16 is configured as described above, when the portion of the reflecting means 16 is imaged from the front in the horizontal direction by the CCD camera 17 comprising an area sensor, the CCD camera 17 has six surfaces of the tablet S as shown in FIG. Reflected from the image, that is, the front image S ₁ that is directly viewed from the front, the rear image S ₂ reflected from the rear mirror 16e, the side image S ₃ reflected from the upper right side reflected from the side mirror 16a, and the side mirror 16b. 6 of the side image S ₄ viewed from the lower right side, the side image S ₅ reflected from the upper left side reflected from the side mirror 16c, and the side image S ₆ viewed from the lower left side reflected from the side mirror 16d. An image of the surface is taken simultaneously. Therefore, if the appearance inspection of the tablet S is performed by image processing using the image data of the six-sided images simultaneously captured, an accurate and reliable appearance inspection can be performed on the entire circumferential surface of the tablet S by one imaging. It becomes possible.

  In FIG. 1, reference numerals 21a and 21b denote illumination devices that illuminate the imaging point P of the tablet, 22 denotes a camera trigger sensor for taking the imaging timing of the CCD camera 17, and 23 denotes the CCD camera 17 and the illumination devices 21a and 21b. A light shielding case covering the whole, 24 is an operation panel, and 25 is a monitor device such as a liquid crystal display.

Next, the operation of the appearance inspection apparatus according to the reference embodiment will be described.
After putting a predetermined amount of tablets S into the supply hopper 11, the operation panel 24 is operated to start processing. The loaded tablets S are sequentially discharged while being aligned at a predetermined interval by the aligning device 12, and are sent out toward the vertical dropping chute 14 by the vibration feeder 13.

  The tablet S that has reached the vertical drop chute 14 has a predetermined posture (in the illustrated example, a circle) by the guide groove 14a of the vertical drop chute 14 and the guide hole 14b (see FIGS. 2 and 3) that follows the guide groove 14a. It slides down while being corrected so that the front and back sides face the CCD camera 17), is discharged vertically downward from the opening at the lower end of the chute, and starts to fall vertically according to gravity.

  When the vertical drop of the tablet S is started, the camera trigger sensor 22 installed in the vicinity of the lower end opening of the vertical drop chute 14 detects the start of the drop of the tablet S and sends a detection signal to a control device (not shown). . The control device takes a timing based on this detection signal, and when the vertically falling tablet S has just reached the position of the imaging point P, the control device operates the electronic shutter of the CCD camera 17 so that the tablet S positioned at the imaging point P is moved. Take an image.

As a result, the CCD camera 17 simultaneously captures six-plane images S _{1 to} S ₆ for the tablet S as shown in FIG. Then, the image processing apparatus (not shown) performs predetermined image processing based on the image data of the six-plane images S _{1 to} S ₆ for the tablet S illustrated in FIG. Judge the quality.

  When it is determined that there is no abnormality in the appearance of the tablet S, the sorting flap 18a of the non-defective product / defective product sorter 18 is rotated to the left position shown by the solid line in FIG. As a result, the tablet S guided to the collection chute 15 and guided to the non-defective / defective product sorter 18 slides down to the non-defective product carry-out conveyor 19 side and is carried out to the next process by the non-defective product carry-out conveyor 19. Is done.

  On the other hand, when it is determined that the tablet S has an appearance abnormality, the sorting flap 18a of the non-defective product / defective product sorter 18 is rotated to the right position indicated by the two-dot chain line in FIG. Thereby, the tablet S having an appearance abnormality slides down toward the defective product storage box 20 and is stored in the defective product storage box 20. In this way, it is possible to select only tablets with no appearance abnormality. Each processing status is displayed on the monitor device 25 as necessary.

As described above, according to the appearance inspection apparatus according to the above-described reference embodiment , images of the six faces of the vertically falling tablet S, that is, the front image S ₁ , the back image S2, and the side image S viewed obliquely from the upper right side. _3. A six-sided image of a side image S ₄ viewed from the lower right side, a side image S ₅ viewed from the upper left side, and a side image S ₆ viewed from the lower left side can be obtained simultaneously. Appearance inspection can be performed on the entire peripheral surface of the tablet S. For this reason, it is possible to perform a more accurate and more complete appearance inspection as compared with a conventional appearance inspection apparatus that cannot simultaneously obtain a six-surface image by one imaging.

Next, on the premise of the above reference embodiment, an embodiment of an appearance inspection apparatus according to the present invention will be described with reference to the drawings. Since this embodiment is different from the above-described reference embodiment only in the arrangement of the mirrors constituting the reflecting means, only the reflecting means and its peripheral part are shown below, and other parts are not shown. Is omitted.

5 and 6 show the configuration of the reflection means 26 used in the appearance inspection apparatus according to the embodiment of the present invention. Similar to the reflection means 16 used in the reference embodiment , the reflection means 26 includes four side-view mirrors 26a to 26d having a square shape in plan view and one rear-view mirror 26e having a cross-section "<". However, the arrangement of the four side mirrors 26a to 26d for taking out the side images is different from that of the reflecting means 16.

In other words, the reflecting means 26 used in the present invention is arranged such that the side mirrors 26a and 26b of the four side mirrors are positioned on the left and right side surfaces in the horizontal direction of the imaging point P and the side mirrors 26c and 26d. Is located on the upper and lower side surfaces of the imaging point P in the vertical direction.

  Of these four side mirrors, the side mirrors 26a and 26b arranged on the left and right side surfaces of the imaging point P are arranged right next to the imaging point P, that is, right next to the tablet S located at the imaging point P. As shown in FIG. 6B, the side mirrors 26c and 26d disposed at the upper and lower side positions of the imaging point P can be prevented from colliding with the vertically falling tablet S. It is necessary to dispose to the front side (or the rear side indicated by a two-dot chain line) of the drop path of the tablet S.

  On the other hand, the rear mirror 26e having a cross-section “<” shape is disposed opposite to the CCD camera 17 with the imaging point P in between, like the rear mirror 16e used in the above-described reference embodiment. The back image of the tablet S is reflected twice by a mirror surface having a “<” shape and guided to the front side so as to be incident on the CCD camera 17.

FIG. 7 shows a captured image of the tablet S by the CCD camera 17 when the reflecting means 26 is used. When the reflecting means 26 having the mirror arrangement is used, as shown in the figure, the front image S ₁₁ directly visible from the front, the back image S ₁₂ reflected from the back mirror 26e, and reflected from the side mirror 26a. right side image _{S 13,} the left side image _{S 14} has been reflected from the side mirror 26b, the side surface image _{S 15} after having been reflected from the side mirrors 26c, six sides image of the lower face images _{S 16} that has been reflected from the side mirrors 26d simultaneously Obtainable. For this reason, as in the case where the reflection means 16 is used, the appearance inspection can be performed on the entire peripheral surface of the tablet S by one imaging.

The side mirrors 26c and 26d arranged in the vertical direction are shifted to the front side (or rear side) of the dropping path so as not to collide with the falling tablet S, as shown in FIG. since it is arranged, the lower side image S ₁₆ as viewed from the upper side image S ₁₅ and the lower side as viewed from the upper side becomes a perspective image viewed from an oblique direction as shown in FIG. 7, the side surface of the upper and lower tablet Not only the front and back surfaces of the tablet are reflected, but the side surface itself is copied, so there is no problem in image processing using a six-sided image.

The reference embodiment and the embodiment described above, with the reflection mirror 16e (26e), to position the upper mirror surface of the mirror body to be shaped cross-section "V" directly behind the imaging point P, reflected in the upper mirror The back image of the tablet is reflected toward the lower mirror surface, and is reflected toward the CCD camera 17 from the lower mirror surface. On the contrary, the lower mirror surface is positioned directly behind the imaging point P. The back image of the tablet reflected on the lower mirror surface may be reflected toward the upper mirror surface and reflected from the upper mirror surface toward the CCD camera 17. In the illustrated example, the rear mirror 16e (26e) having a cross-section “<” shape is vertically placed along the vertical direction, but it can also be turned horizontally by turning 90 degrees.

1 is a schematic side view showing an overall configuration of an appearance inspection apparatus according to a reference embodiment of the present invention. FIG. 2 is a schematic perspective view of a reflecting means and a CCD camera portion in FIG. 1. (A) is the schematic front view which looked at the reflection means of FIG. 2 from the CCD camera side, (b) is the schematic sectional drawing in the II line position in (a). It is a figure which shows the picked-up image of the CCD camera obtained by the reflection means of FIG. It is a schematic示斜view showing the configuration of a reflecting means employed in the appearance inspection apparatus according to the present invention. (A) is the schematic front view which looked at the reflection means of FIG. 5 from the CCD camera side, (b) is the schematic sectional drawing in the II-II line position in (a). It is a figure which shows the picked-up image of the CCD camera obtained by the reflection means of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Supply hopper 12 Alignment apparatus 13 Vibrating feeder 14 Chute for vertical drop (vertical drop means)
15 Collecting chute 16, 26 Reflecting means 16a to 16d, 26a to 26d Side mirrors 16e, 26e Rear mirror 17 CCD camera (imaging means)
18 Non-defective / defective product sorter (good / defective product sorting means)
DESCRIPTION OF SYMBOLS 19 Conveyor for carrying out non-defective product 20 Defective product storage box 21a, 21b Illuminating device 22 Trigger sensor for camera 23 Shading case 24 Operation panel 25 Monitor device S Tablet (inspection object)
P imaging points S _{1 to} S ₆ , S _{11 to} S ₁₆ captured images (6-plane images)

Claims (2)

In the appearance inspection method in which the inspection object being conveyed is imaged by the imaging means, and the quality of the appearance of the inspection object is determined by performing image processing on the image data of the obtained captured image.
In the middle of the transport path, a vertical drop unit is provided that allows the object to be naturally dropped according to gravity.
An imaging point of the inspection object is set on the vertical drop part, and an imaging unit including an area sensor is disposed at a horizontal front position facing the imaging point.
Further, around the imaging point, four side mirrors are arranged so as to surround the imaging point at right angles to the vertical and horizontal positions of the imaging point, and a cross-section “<” is formed on the back side of the imaging point. Place one rear-view mirror,
The object to be inspected is corrected to a predetermined posture in the vertical drop part and allowed to fall naturally,
When the falling inspection object is positioned at the imaging point, four side images of the inspection object reflected from the four side mirrors on the top, bottom, left and right, and the front mirror face the front side. captured simultaneously with the back image of the object coming is reflected by the imaging means comprising an image of a total of six sides of the front image from the area sensor of the object to be viewed directly from the front position Te,
Appearance inspection method characterized by performing quality determination of the appearance of the object to be inspected by using the image data of the imaged six sides of the captured image at the time of identity. In the appearance inspection apparatus that images the inspection object being transported by the imaging means and determines the quality of the appearance of the inspection object by performing image processing on the image data of the obtained captured image.
A vertical drop means for the inspection object provided in the middle of the conveyance path;
Reflecting means disposed at the imaging point of the inspection object set at a predetermined position directly below the vertical dropping means,
An imaging means comprising an area sensor that images the inspection object from a horizontal front position when the inspection object falling vertically is positioned at the imaging point;
A non-defective product / defective product sorting means that is provided on the lower side of the reflecting means and distributes the inspected object falling according to the result of the quality determination of the appearance to a non-defective product and a defective product;
The vertical drop means corrects the object to be inspected to a predetermined posture and naturally drops it,
The reflecting means is arranged orthogonally to the vertical position and the horizontal position of the imaging point so as to surround the imaging point, and the four vertical and horizontal images of the outer peripheral side surface of the inspection object positioned at the imaging point are Four side mirrors that reflect toward the imaging means, and a cross-section "<" that is disposed on the back side of the imaging point and reflects the back image of the object located at the imaging point toward the imaging means A visual inspection apparatus comprising a single rear-view mirror .

Images