JPH06103170B2 - Appearance inspection method and device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention determines the appearance surface state (color, scratch, stain, pattern, etc.), shape, and size of an article such as fruit or vegetable conveyed by a conveyor or the like. The present invention relates to a method and a device for measuring and inspecting and automatically sorting by grade.

[Conventional technology and problems]

For example, when selecting spherical articles such as fruits and vegetables (hereinafter simply referred to as articles) by classifying and grading them according to the shape, size, color, and surface condition such as scratches, the shape and size of the article Since it is necessary to capture images of the part indicating the and the entire circumference surface state, conventionally, there are the following methods for inspecting the shape, size, and appearance surface state of articles conveyed one by one by a conveyer or the like.

(A) A method of disposing one sensor camera 3 above or to the side of the conveyor 1 as shown in FIG. 11 and imaging and inspecting one surface of the conveyed article 5.

(B) A method in which two sensor cameras 3 are arranged on both sides of the conveyor 1 as shown in FIG. 12, and both sides of the conveyed article 5 are imaged and inspected.

(C) As shown in FIG. 13, an article is dropped from the conveyor 1a to another conveyor 1b, four sensor cameras 3 are arranged on the side of the fall path, and four sides of the falling article 5 are imaged. How to inspect.

(D) As shown in FIG. 14, the article 5 is conveyed while being rotated at a high speed in the traveling direction by the roller conveyor 1c, etc., and one sensor camera 3 is arranged above the conveyance path, and the outer peripheral portion of the rotating article is arranged. There is a method of imaging and inspecting.

However, according to the method (a), since only the top surface or one side surface of the article is inspected, the inspection range is limited to a very small part of the entire circumference surface, and many surfaces not inspected are appropriate. I can't sort.

Since the above method (b) inspects both side surfaces of the article, the inspection range is larger than that in the method (a), but even with this, many surfaces are not inspected and proper selection cannot be performed. In particular, if the shape and size of an article differ greatly depending on the direction, such as lemon, the size of the image will differ depending on whether the axis is in the sideways orientation or when the axis is in the traveling direction. Since it is impossible to measure and inspect various dimensions, there is also a problem that the articles must be aligned in a certain direction.

Since the method of (c) above inspects the four sides, the measurement range is wider than the method of (b) above. Since it is not controlled, there is a drawback that the shape and size of the part showing the size of the article cannot be measured.

The method of (d) above can inspect the surface around the body of an article shaped like a lemon that can rotate around the body at a high speed around the axis, but it does not inspect the two sides in the axial direction of rotation, and further rotates with rollers. An article that has an unstable posture when it is caused has drawbacks such as sideways rotation and jumping. In addition, since the number of rotations is different for articles of various sizes, small ones make one or more revolutions in the same imaging time, so a part of the outer circumference is inspected redundantly, and large ones may not make one revolution. There is a problem that the surface that is not inspected remains.

Furthermore, the methods of (c) and (d) above have a wider inspection range than those of (a) and (b), but by dropping the item or rotating it at a high speed, the item may be bruised. It has not been put to practical use due to its drawbacks such as damage to the commercial value of the article due to damage such as scratches and scratches.

[Object of the Invention]

The object of the present invention is to convey the articles supplied separately on the conveying conveyor one by one in the front and rear, and to convey the articles, and to show the size of the article, and the entire outer circumference of the exposed portion except the lower surface in contact with the conveyor. A method and apparatus for measuring and inspecting the surface condition.

[Means for solving problems]

The present invention has been made to achieve the above object, in the method, on the left and right sides sandwiching the transport path of the transport conveyor for transporting the object to be measured, opposed at a position inclined by 45 degrees to the traveling direction. In addition to providing a mirror, the article conveyed by the conveyor is illuminated from the front side and the rear side with respect to the intersecting field of view of the mirrors arranged opposite to each other, and the article is conveyed to the left from the center in the conveying direction among four different side surfaces of the article. First imaging that reflects the 1/4 side surface and the right 1/4 side surface upward, and scans the image of the top surface of the article and both left and right mirror surfaces using a single sensor camera from a predetermined position above the conveyor. Steps, and in the direction orthogonal to the scanning line of the sensor camera, mirrors are provided so as to face each other on both left and right sides of the transport path of the transport conveyor, and a front side and a back side that sandwich a field of view of the mirrors arranged to face each other. From the transfer Illuminate the article to be conveyed by the muffler, and reflect the left 1/4 side surface and the right 1/4 side surface of the four different side surfaces other than the two side surface images captured in the first imaging step upward. A second imaging step of scanning the upper surface and both left and right mirror surfaces of the article using a single sensor camera from a predetermined position above the transport conveyor, and a plurality of images captured in the first imaging step and the second imaging step. It is characterized by including a step of measuring and inspecting the shape dimension and the surface state of the article by image-processing the imaging surfaces respectively, and as the apparatus, the articles to be measured are separated one by one and placed on the conveyor. Mirrors are provided on both the left and right sides of the transporting means for transporting and the transporting path on which the article is transported by the transporting means so as to face each other at a position inclined by 45 degrees with respect to the traveling direction. Center of transport direction out of two sides Luo left 1/4
First reflecting means for reflecting the side surface and the right 1/4 side surface upward, and from the front side and the rear side sandwiching the intersecting field of view of the mirrors arranged facing each other of the first reflecting means, using the lighting means, the conveyor. Of the first image pickup means for illuminating an article conveyed by a sensor camera provided at a predetermined position above the conveyer, and scanning the mirror surface of the mirror arranged to face the upper surface of the article. In the direction orthogonal to the scanning line scanned by the sensor camera, mirrors are provided facing each other on both left and right sides of the transport path of the transport conveyor, and two side surfaces of the four different side surfaces reflected by the first reflecting means. From the front side and the back side sandwiching the intersecting field of view of the mirrors arranged opposite to each other, the second reflecting means for reflecting the left 1/4 side surface and the right 1/4 side surface other than the image upward , Using the lighting means While illuminating the article, the sensor camera provided above the predetermined position of the transfer compare,
A second imaging means for scanning the upper surface of the article and the mirror surface of the second reflecting means; and means for respectively image-processing the plurality of imaging surfaces imaged by the first imaging means and the second imaging means. It is a feature.

〔Example〕

Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings.

The outline of the present invention will be described with reference to FIGS. 1 and 2.

1 is a conveyer conveyor, 2a, 2b, 2c, 2d are mirrors, 3A and 3B are sensor cameras, 4 is a lighting device, and 5 is an article. As shown in FIG. Is a hexahedron consisting of top and bottom surfaces, left and right surfaces, and front and back surfaces, and the left oblique rear side surface 5a, the right oblique front side surface 5b, and the right oblique rear side surface with respect to the traveling direction.
5c, a left oblique front side surface 5d, a plane surface 5e, and a bottom surface 5f.

The conveyor 1 is for separating the articles 5 one by one in a row in the front and rear and randomly conveying them, and uses a conveyor device as previously proposed by the present applicant in Japanese Patent Application Laid-Open No. 58-135026. However, other sorting conveyors can be used.

The mirrors 2a, 2b, 2c, 2d are side surfaces 5a, 5b, 5c, 5d of the article 5 in four directions.
Is reflected in a predetermined direction. As shown in FIGS. 4 and 5, mirrors 2a and 2b are opposed to the left and right sides sandwiching the conveyer conveyor 1 at positions inclined by 45 degrees with respect to the traveling direction, respectively.
Out of the four side views of the article 5, the rear left side 5a in the traveling direction
And the diagonally right front side surface 5b are provided so as to be reflected by the upper sensor camera 3A, respectively, and the scanning line of the sensor camera 3A is provided.
In a direction orthogonal to 30A, mirrors 2c and 2d are opposed to each other on both left and right sides of the conveyor 1, so that the right oblique rear side surface 5c and the left oblique front side surface 5d of the article 5 are reflected by the upper sensor camera 3B. Each of them is provided at a predetermined angle.

The mirrors 2a, 2b, 2c, 2d are the scanning lines 30 of the sensor cameras 3A, 3B.
It is sufficient that A and 30B are located at the scanning position, and it is formed to have a relatively small width, and the length of the inclined surface is set to a length that covers the visual field determined by the size of the article 5.

The sensor cameras 3A and 3B are cameras using a MOS-type or CCD-type linear image sensor 31 (Fig. 6), and more specifically, RGB light-receiving elements of light-receiving elements used in color facsimiles, color copying machines, etc. It is preferable to use a color linear image sensor with a filter formed on-chip or a three-plate color linear sensor camera.

The sensor cameras 3A and 3B are arranged at predetermined positions above the first and second inspection positions 11 and 12 on the conveyor 1 shown in FIG. 2, and the scanning lines 30A and 30B of the sensor cameras 3A and 3B are arranged on the conveyors. It is installed at a position where the left and right fields of view are equally distributed in a direction that crosses the direction of 1 diagonally 45 degrees.

Further referring to FIG. 6, linear image sensor 31A (31B)
The image pickup area will be described.

The imaging area of the linear image sensor 31A (31B) is
A ₁ (D ₁ ) is the first element of the scanning line, C ₂ (F ₂ ) is the last element, and the element surface of A (D) is the right diagonal front side surface 5b (right diagonal rear side surface 5c) of the article 5. Image area, B (E) element surface
The image area of the flat surface 5e and the element surface of C (F) are the image areas of the left oblique rear side surface 5a (the left oblique front side surface 5d) of the article 5.

As shown in FIGS. 1 and 5, the illuminating device 4 includes the articles 5 conveyed by the conveyor 1 when the articles 5 are on the scanning lines 30A, 30B of the sensor cameras 3A, 3B, before and after sandwiching the scanning lines 30A, 30B. A plurality of small illumination lamps 41 are arranged on the side so as to surround the article 5, and the surface of the article 5 is uniformly illuminated.

Next, the imaging procedure of the article 5 conveyed on the conveyor 1 will be described with reference to FIGS.

The article 5 conveyed by the conveyor 1 is a sensor camera 3A.
When it reaches a position crossing the scanning line 30A, the images of the left diagonal rear side surface 5a, the plane 5e, and the right diagonal front side surface 5b of the article 5 are taken at every scanning from A ₁ to C ₂ of the linear image sensor 31A. Then, the scanning is repeated by a scan start pulse (not shown) which is started each time the conveyor 1 advances by a predetermined unit size. The left oblique rear side surface 5a, the flat surface 5e, and the right oblique front surface 5b of the article 5 imaged in this way are respectively the ninth
An image is formed as shown in the figure.

On the other hand, the article 5 that has passed through the scanning line 30A of the sensor camera 3A and is conveyed further ahead is the scanning line 30B of the sensor camera 3B.
When reaching a position crossing, the linear image sensor 31B repeats the scanning in the same manner as described above, and diagonally moves to the respective positions (imaging device surface) of D, E, and F assigned on the linear image sensor 31B to the right. The rear side surface 5c, the plane surface 5e, and the left oblique front side surface 5d are imaged to form an image on each surface as shown in FIG.

The process of combining the image of each surface of the first inspection position 11 (FIG. 9) captured in this manner with the image of each surface of the second inspection position 12 (FIG. 10) is the first inspection. The image of the article 5 is stored at the same time when the photographing is completed at the position 11, and the conveyer conveyor 1 detects the distance (interval) from the imaging start point of the first inspection position 11 to the imaging start point of the second inspection position 12. Using a device that generates a signal each time a predetermined unit progresses, for example, an encoder (not shown), counts the signals (pulses) generated by the encoder and waits in order (shift control) An image (FIG. 9) captured and stored at the position 11 and an image (FIG. 10) captured at the second inspection position 12 can be combined and processed at the same time.

Of the images taken as described above, the images of the plane 5e of the article 5 taken at the first inspection position 11 and the second inspection position 12 are the same, and either one of the images is taken at the image processing stage. It may be unprocessed. In the present embodiment, the image of the plane surface 5e captured on the second inspection position 12 side is processed as unprocessed.

Of the images of the respective surfaces formed as described above, the image of the plane surface 5e is as shown in FIGS. 9 and 10 in order to scan in the direction oblique to the conveying direction of the article 5 by 45 degrees. Since distortion that is deformed in the diagonal direction of 45 degrees occurs, image correction processing of 45 degrees distortion is performed. From the corrected image of the plane 5e, the shape dimensions of the article 5 (circle diameter, major axis, minor axis, area, perimeter, etc.)
Is analyzed and calculated.

The dimension of the article 5 in the height direction is four side images 5a, 5b, 5c, 5
The average value of the heights Ha, Hb, Hc, and Hd of d is measured as the height of the article 5.

The surface condition (color, scratches, etc.) of the article 5 can be determined from the images of the four side surfaces 5a, 5b, 5c, 5d and the plane 5e excluding the lower surface of the article 5, the degree of coloring (lightness, hue, saturation), the size of the injury point. To calculate

The shape and size of the article 5, the color of the surface, and the scratches are measured by the above method, and compared with standard values set in advance by an arithmetic processing unit (not shown), and graded to the corresponding grades and classes, respectively, for sorting and sorting. It can be performed.

As described above, the treatment of the surface condition of the article 5 can be performed by, for example, Japanese Patent Laid-Open No.
Known techniques disclosed in Japanese Patent Publication No. 87081 can be used.

The above description and the attached drawings are merely examples of the embodiments of the present invention, and do not limit the invention.
Of course, it is also applied to the arrangement.

〔The invention's effect〕

According to the present invention, two cameras are provided above the conveyor as described above, and scanning is performed in a direction inclined by 45 degrees with respect to the traveling direction of the article, and the scanning lines of the cameras are arranged in directions orthogonal to each other, and the scanning is performed. Mirrors are arranged on both the left and right sides of the line that crosses the conveyor at 45 degrees, and it is configured to image the top surface of the article and four different side surfaces. It is possible to inspect the surface condition of the five surfaces except for, for example, the goods such as fruits and vegetables can be classified more accurately according to the grade, and uniform fruits can be provided with good assortment. .

Further, the article can be measured and inspected instantly without rolling on the conveyor while it is being conveyed, and the article is not damaged by bruising or abrasion.

Furthermore, according to the present invention, since it has a simple structure in which a camera and a mirror are combined, it has a feature that it can be easily adjusted and inspected.

[Brief description of drawings]

Each of the drawings is an explanatory view showing an embodiment of the present invention. FIG. 1 is a perspective view showing the whole apparatus of the present invention, FIG. 2 is a perspective view showing an imaging state of an article at the center of each inspection position, and FIG.
FIG. 4 is an explanatory view showing each side of the article, FIG. 4 is a sectional view taken along the line AA in FIG. 1, FIG. 5 is a plan view of the device of the present invention, FIG. FIG. 8 and FIG. 8 are explanatory diagrams of allocation of three images detected on the linear image sensor,
FIG. 9 and FIG. 10 are explanatory views of the three captured images. 11 to 14 are explanatory views of a conventional article appearance inspection method. 1 ... Conveyor 2a, 2b, 2c, 2d ... Mirror 3A, 3B ... Sensor camera 30A, 30B ... Scanning line 4 ... Illumination device, 5 ... Article 11 ... First inspection position, 12 ... Second inspection position 41 …… Small illumination lamp 5a, 5b, 5c, 5d, 5e, 5f …… Six sides of article A …… Sloping front right side image plane of article B …… Plane plane of article C …… Article Left diagonal rear side imaging plane D …… Right diagonal rear side imaging plane E …… Flat article plane imaging plane F …… Left diagonal front side imaging plane Ha, Hb, Hc, Hd …… Article height

Claims (5)

[Claims] 1. A mirror is provided on both left and right sides sandwiching a conveyance path of a conveyer for conveying an object to be measured so as to oppose at a position inclined by 45 degrees with respect to a traveling direction, and a field of view where the opposed mirrors intersect. Illuminate the article conveyed by the above-mentioned conveyor from the front side and the rear side sandwiching the above, the left 1/4 side surface and the right 1/4 side surface are reflected upward from the conveyance direction center among the four different side surfaces of the article. A first imaging step of scanning an image of the upper surface of the article and both left and right mirror surfaces using a single sensor camera from a predetermined position above the transport conveyor, and in the direction orthogonal to the scanning line of the sensor camera, The mirrors are provided so as to face each other on both left and right sides sandwiching the transport path of the transport conveyor, and the articles transported by the transport conveyor are illuminated from the front side and the rear side that sandwich the intersecting field of view of the facing mirrors, and the different four One side Among them, the left 1/4 side surface and the right 1/4 side surface other than the two side surface images captured in the first imaging step are reflected upward, and one sensor camera is used from a predetermined position above the transport conveyor. A second imaging step of scanning the upper surface of the article and both left and right mirror surfaces, and image processing of the plurality of imaging surfaces imaged in the first imaging step and the second imaging step, respectively, and the shape and surface state of the article. And a step of measuring and inspecting the appearance of the article. 2. The appearance inspection method for an article according to claim 1, wherein the sensor camera uses a linear image sensor on an imaging surface. 3. The appearance of the article according to claim 2, wherein images of the upper surface of the article and the left and right mirror surfaces are taken side by side on a linear image sensor for each scanning. Inspection method. 4. A conveyance means for separating the articles to be measured one by one and placing them on a conveyance conveyor and conveying them, and to the left and right sides sandwiching a conveyance path along which the articles are conveyed by the conveyance means, at an angle of 45 degrees with respect to the traveling direction. The first reflecting means for reflecting the left 1/4 side surface and the right 1/4 side surface upward from the conveyance direction center among the four side surfaces different from each other on the left, right, front and back of the moving article by providing a mirror facing each other, From the front side and the rear side sandwiching the intersecting field of view of the mirrors arranged facing each other of the first reflecting means, the illumination means is used to illuminate the article conveyed by the conveyor, and the sensor is provided at a predetermined position above the conveyor. A first image pickup means provided with a camera for scanning the mirror surface of the mirror arranged to face the upper surface of the article, and a conveyance path of the conveyance conveyor in a direction orthogonal to a scanning line scanned by the sensor camera of the first image pickup means. To Mirrors are provided facing each other on the left and right sides, and the left 1/4 side surface and the right 1/4 side surface other than the two side surface images reflected by the first reflecting means out of the four different side surfaces are upward. Second reflecting means for reflecting, and from the front side and the rear side sandwiching the intersecting field of view of the mirrors arranged facing the second reflecting means, the article is illuminated by using the illuminating means, and a predetermined position above the conveyor. A sensor camera is provided on the second imaging means for scanning the upper surface of the article and the mirror surface of the second reflecting means, and the plurality of imaging surfaces imaged by the first imaging means and the second imaging means are image-processed respectively. A visual inspection device for articles, comprising: 5. A means for processing each of the plurality of image pickup surfaces,
While calculating the dimensions of the plane image of the article from the top view, calculating the shape dimension of the article in the height direction from each of the four side images, and an arithmetic processing unit that classifies the articles by size from the calculated values. 5. The article according to claim 4, further comprising: an arithmetic processing unit that extracts a color and a flaw from each of the five images and grades the article based on the degree of coloring and the size of the flaw. Appearance inspection device.